ROUTE ENGINEERING STUDY FINAL REPORT: A REPORT FOR HS2

High Speed Two Ltd

ROUTE ENGINEERING STUDY FINAL REPORT: A REPORT FOR HS2

DEcEmbER 2009

High Speed Two Final Report

cONTENTS REPORT REFERENcE : HS2-ARP-00-RP-cX-00003-ISSUE-2-FEbRUARY 26.2010

HIGH SPEED 2 1

ContEntS 2

1. IntroDuCtIon 7

1.1. This Route Engineering Report 7

1.2. Historical background 7

1.3. Overview of methodology 7

1.4. Layout of this Report 11

2. rEmIt, rEquIrEmEntS anD aSSumPtIonS 13

2.1. Arup’s Remit 13

2.2. Other Studies 13

2.3. commentary on Alignment Accuracy 13

2.4. Alignment Design Assumptions 15

2.5. Tunnels 16

2.6. Geotechnical Assumptions 18

2.7. Structures Assumptions 20

2.8. Environmental mitigation 20

3. raIlway oPEratIonal anD nEtwork ISSuES 25

3.1. Supporting Reports 25

3.2. VISION modelling for Sectional Running Times 25

3.3. journey times beyond hs2 25

3.4. Journey Time Results 25

4. CaPItal CoStInG anD rISk aSSESSmEnt mEtHoDoloGy 26

4.1. capital cost methodology 26

4.2. Risk Assessment methodology 30

4.3. Optimism bias 32

5. routE 3 34

5.1. Introduction 34

5.2. Euston Station 36

5.3. Euston to Old Oak common 56

5.4. Old Oak common Station (West London Interchange) 60

5.5. Old Oak common to Acton Portal 64

5.6. Acton Portal to Hanger Lane 66

5.7. Hanger Lane 70

5.8. Hanger Lane to South Ruislip 72

5.9. Northolt LUL Station 74

5.10. South Ruislip 76

5.11. South Ruislip to West Ruislip 78

5.12. West Ruislip to amersham tunnel portal 80

5.13. Amersham Tunnel - m25 to west of Amersham 82

5.14. Amersham to Little missenden 84

5.15. Little missenden Tunnel 86

5.16. Little missenden to Wendover 88

5.17. Wendover to Stoke mandeville/Aylesbury 90

5.18. Aylesbury to Quainton 92

5.19. Quainton to brackley 94

5.20. brackley to Ufton / Long Itchington Wood 96

5.21. Long Itchington Wood Tunnel 98

5.22. Ufton / Long Itchington Wood to burton Green 100

5.23. burton Green to the NEc Area 102

5.24. birmingham Interchange Station 104

5.25. Delta Junction 110

5.26. Delta Junction to belfry Golf course 122

5.27. North of the belfry 124

5.28. Lichfield 126

5.29. connection into the West coast main Line 128

5.30. The Link to birmingham 130

5.31. HS2 Ltd’s Preferred birmingham Station - Fazeley Street 144

5.32. THE ALTERNATE LINK TO bIRmINGHAm 150

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cONTENTS REPORT REFERENcE : HS2-ARP-00-RP-cX-00003-ISSUE-2-FEbRUARY 26.2010

5.33. The Alternative birmingham Station - Warwick Wharf Station 152

5.34. costs and Risk 156

5.35. Journey Time Results – Route 3 158

6. routE 2.5 160


6.2. West Ruislip to Denham 162

6.3. Gerrards cross Tunnel 164

6.4. Gerrards cross to Hazlemere 166

6.5. Hazlemere to Princes Risborough 168

6.6. Princes Risborough to brackley 170

6.7. costs and Risk 172

6.8. Journey Time Results – Route 2.5 174

7. routE 4 176

7.1. Old Oak common to Kings Langley Tunnel 176

7.2. Kings Langley to cheddington 178

7.3. cheddington to Whaddon 180

7.4. Whaddon to catesby 182

7.5. catesby New Tunnel 184

7.6. catesby to Lower Shuckburgh 186

7.7. Lower Shuckburgh Tunnel 188

7.8. Lower Shuckburgh to crackley 190

7.9. Route Termination – crackley 192

7.10. Total Route 4 costs and Risk 194

7.11. Journey Time Results – Route 4 196

8. oPtIonS for ConnECtInG to HEatHrow 198


8.2. Terminal 5 – Terminus Station 198

8.3. Terminal 5 – Through Station 200

8.4. Terminal 6 – Terminus Station 202

8.5. Terminal 6 – Through Station 204

8.6. Iver – Through Station 206

8.7. Iver – Terminus Station 208

8.8. Track Alignment Options – Loops, Spurs and Through Routes 210

8.9. Loop Design from Route 3 210

8.10. Spur Design from Route 3 220

8.11. Serving Heathrow from Route 2.5 223

8.12. Serving Heathrow from Route 4 223

8.13. capital cost of Heathrow Options 224

8.14. journey times via heathrow 224

9. oPtIonS for tHE HS1 to HS2 ConnECtIon 226

9.1. The Incremental Nature of the Study 226

9.2. Option 1 226

9.3. Option 2 228

9.4. Option 3 230

9.5. capital cost of the HS1 connection 230

10. oPtIonS StuDIED In StaGE 3 232

10.1. The Stage 3 Process 232

10.2. London Station - Deep ‘cavern’ Stations at Paddington 232

10.3. London Station - Kings cross Lands 234

10.4. London Station – Euston (Options 1 and 2) 236

10.5. Line of Route - m1 corridor (Hemel Hempstead to Edlesborough) 238

10.6. Line of Route - Route 2 (chiltern Line corridor) 240

10.7. Line of Route - Route 1 m40 (Denham to Aynho) 244

10.8. Line of Route - Gaydon to chipping Warden 246

10.9. Line of Route - brackley to catesby 248

10.10. West midlands - On-line Widening: Lapworth to moor Street 250

10.11. birmingham Outer Eastern bypass 254

10.12. birmingham Inner Eastern bypass 256

10.13. West midlands Station - birmingham moor Street East (Through) 258

4 High Speed Two Final Report

10.14. West midlands Station - birmingham moor Street East Terminus 260

10.15. West midlands Station - birmingham New Street 262

10.16. West midlands - central birmingham to the North-West 264

10.17. Heathrow Option - Ealing broadway 266

10.18. Heathrow Option – Southall 268

10.19. capital cost Estimates for Options not pursued in stage 3 268

11. oPtIonS StuDIED In StaGE 2 270


11.2. London Stations - Introduction 270

11.3. London Station - Willesden Junction (Terminus) 270

11.4. London Station “Royal Parks 1” - Hyde Park 272

11.5. London Station “Royal Parks 2” - Regent’s Park 274

11.6. London Station - St Pancras 1 276

11.7. London Station - St Pancras 2 278

11.8. The midland main Line / m1 corridor 280

11.9. chiltern Line (South Ruislip to Neasden) 282

11.10. m40 (Stokenchurch to Heathrow) 284

11.11. m4 corridor (Old Oak cOmmON to Heathrow) 286

11.12. Line of Route - chiltern Line/m40 (Princes Risborough to Warwick) 288

11.13. Line of Route - m40 Stokenchurch to Warwick 290

11.14. West midlands Option - Fully Tunnelled m42 to city centre 292

11.15. West midlands - Stechford to Perry bar 294

11.16. A West midlands Western bypass 296

11.17. South-Westerly Approaches to birmingham 298

11.18. West midlands Approach from Nuneaton – bedworth Gap 300

11.19. Through birmingham Routes 302

11.20. West midlands Station - moor Street West 304

11.21. West midlands Station - curzon Street (Through) 306

11.22. birmingham Station - Underground Through Station 308

11.23. Heathrow Options - North Pole 310

11.24. Heathrow Options - Acton Yard Interchange 312

11.25. Heathrow Options - Hayes and Harlington 314

11.26. Heathrow options - GWmL Heathrow Interchange 316

11.27. capital cost Estimates for Options not pursued in stage 316

5

There is a series of Appendices.

Appendix A contains a full account •

of the tunnelling studies

Appendix b sets out Tunnelling •

Ventilation Requirements

Appendix c sets out Geotechnical Assumptions•

Appendix D describes Structures Assumptions•

Appendix E describes route alignment issues •

between Old Oak common and Ruislip;

Appendix F is the cost Risk Register.•

Appendix G is a List of Drawings•

Appendix H : maintenance Depot •

Appendix I is the birmingham •

New Street Station Report


7

tHIS routE EnGInEErInG rEPort1.1.

This Arup report was prepared in response to a remit from High Speed Two Limited (HS2 Ltd). The report presents the findings of a route engineering and alignment study for a potential new high-speed rail line from London to the West midlands.

Although a very large range of engineering issues were considered during route development, this report focuses on two key topics:

Where would a route go?•

How much would it cost? •

HIStorICal BaCkGrounD1.2.

In January 2009, the Government established HS2 Ltd with a remit to undertake studies into a new high-speed line between London and birmingham. The letter establishing HS2 Ltd also set out a wide range of considerations that the HS2 project team would have to consider. In February 2009, the chairman of HS2 Ltd expanded on the proposed approach to the studies in a letter to Lord Adonis.

Arup was then appointed by HS2 Ltd on 19th may 2009 for a series of route engineering studies. In parallel to the appointment of Arup, HS2 Ltd appointed booz Temple as their environmental/sustainability advisors. Arup and booz Temple worked closely together throughout the duration of this commission.

ovErvIEw of mEtHoDoloGy1.3.

HS2 Studies1.3.1.

In April 2009, HS2 Ltd undertook internal studies to generate and appraise (at a very strategic level) a huge number of options for:

London Stations;•

London Approaches;•

West midlands Options;•

West midlands Stations;•

Heathrow Options;•

Line of Route Options;•

Network connections.•

The HS2 Ltd options were described to Arup and booz Temple= at two Option Workshops, held on June 2nd and June 5th. At these Workshops, further options were considered to complete a full list of options. HS2 Ltd then appraised the added options in the same manner as their April work, in order to sift out the less favoured schemes.

As a result of all this appraisal work HS2 Ltd prepared a definitive list of routes / corridors / stations options that became the focus of this study. They agreed that some options would not be carried forward; those that were are described later in this report.

The Stage Gate 2 Report 1.3.2.

Arup then prepared drawings for the whole route concepts, and for the station layout options. Each route was then broken up into individual links sharing common attributes (open country, tunnel, existing rail corridor).

HS2 Ltd constructed a “template” for each link, populating it with engineering assessments arising from the Arup work, environmental and sustainability assessments from booz Temple, and their own internal assessments on other issues. The alignment work was undertaken on plan only, with little vertical detail, but with recognition of general topographical implications. costs were derived on a “per route-km” basis, nominating a single type of solution for the whole of a link.

Arup presented its engineering findings to HS2 Ltd at a series of short-listing meetings, one for each geographical grouping. This engineering work was presented alongside that of the other consultants, principally the booz Temple inputs. This stage of the process was known as Stage Gate 2 (end of June 2009).

As a result of these meetings, HS2 Ltd, in conjunction with its stakeholders, decided which routes and stations should be not be pursued

INTRODUcTION1.


9

in order to focus attention on a shorter list. This process was also known as a “sift”.

The Stage Gate 3 Report1.3.3.

The short-listed routes were then developed in plan and longitudinal profile, and route alignments adjusted to suit emerging environmental constraints. Each remaining option was developed on Ordnance Survey mapping in order to produce centre-line alignments, horizontally and vertically. The routes were then sub-divided into geographical sections. Outline comments on the materials and geotechnical issues were made based on the digital information provided by the british Geological Society.

A cost was produced for each geographical section, taking engineering and material quantities from the engineering drawings. The geographical sections were then aggregated into whole route totals. costs were still on a “per route-km” basis, but in Stage 3, each link was sub-divided by the type of engineering solution.

The output of this work was reported to HS2 Ltd (in exactly the same meetings format as at Stage Gate 2) for the Stage Gate 3 review (end of September 2009). Again, following the same process, HS2 Ltd decided not to pursue a number of routes and stations, and attention again focussed on a shorter list of candidate routes. Another “sift” took place. Essentially, three main routes remained.

HS2 Ltd’s Preferred Route1.3.4.

Further work was undertaken on the remaining three routes in September / October 2009.

This work consisted of considerably more “depth” in terms of horizontal and vertical location, further refining emerging outputs from initial sustainability appraisal. more cognisance was taken of constraints posed by existing major roads, railways and major watercourses. For stations, much more work was done on layouts, facilities, passenger circulation etc. A further set of alignment drawings was then prepared.

The remaining options were re-costed, but at a much greater degree of disaggregation. Individual quantities were derived, and matched against a large database of unit rates.

meetings were held with the Highways Agency to understand the major implications on the motorway and trunk road network, particularly in the West midlands. The Highways Agency also provided level information on the major motorways, and information on major structures.

Of these last three routes, one (Route 3) emerged as HS2’s Preferred Route. Arup presented factual information to a series of Working Groups, but the route preferences were taken by HS2 Ltd.

The location, layout and engineering issues associated with this Route are described. There are two other main but less favoured alternatives to Route 3: Route 2.5 (the nomenclature is explained later), and Route 4.

The other routes in the Stage Gate 2 and Stage Gate 3 work are then described, at a correspondingly less level of detail, in the remaining chapters.


11

layout of tHIS rEPort1.4.

The remainder of this report is laid out as follows:

chapter 1, this chapter, is introductory;•

chapter 2 concerns Arup’s Remit, •

Requirements and Assumptions

chapter 3 sets out some railway •

operational and network Issues

chapter 4 describes the approach to •

capital costing and risk assessment

chapter 5 describes Route 3 – HS2 •

Limited’s Preferred Route;

chapter 6 describes Route 2.5;•

chapter 7 describes Route 4;•

chapter 8 describes options for •

connecting to Heathrow Airport;

chapter 9 describes options for •

connecting HS2 to HS1;

chapter 10 describes options •

studied in Stage 3 of the study;

chapter 11 describes options •

studied in Stage 2 of the study.

There is a series of Appendices.

Appendix A contains a full account •

of the tunnelling studies

Appendix b sets out Tunnelling •

Ventilation Requirements

Appendix c sets out Geotechnical Assumptions•

Appendix D describes Structures Assumptions•

Appendix E describes route alignment issues •

between Old Oak common and Ruislip;

Appendix F is the cost Risk Register.•

Appendix G is a List of Drawings•

Appendix H concerns a maintenance Depot •

Appendix I is the birmingham •

New Street Station Report


HS2 cONNEcTIONS

13

aruP’S rEmIt2.1.

Essentially, the remit from HS2 Ltd was to develop route options with the requirement to:

provide a route from London to the •

West midlands, with connections to existing rail networks in such a way that the West coast main Line (WcmL) south of Rugby would be relieved;

connect London to central birmingham;•

provide for trains of 400m in length, •

formed of 2 x 200m units, capable of splitting and joining in platforms;

achieve a line speed of 400kph wherever •

practicable and reasonable to do so;

achieve minimum journey times, but with •

no particular time aspiration specified;

design for 15 trains per hour, each providing •

for 1032 passengers per train, thus giving a total demand of over 15,000 passengers per hour approaching the London area;

provide a route capacity of 20 trains per hour •

(3-minute headways) such that the proposed 15tph would use 75% of the capacity;

provide platforms at stations based •

around a utilisation of 2 trains per hour per platform (30 minute repeating cycle);

provide a terminal station in London •

with 10 platforms for a maximum of 20 trains per hour, such that 15tph would use 75% of the capacity;

provide a station in birmingham with •

4 (later expanded to 6) platforms;

consider the opportunities for •

connecting to HS1;

consider the opportunities for interchange •

(or direct links to ) Heathrow Airport.

In addition to the above key requirements, HS2 Ltd prepared a Project Specification giving a range of other technical parameters.

otHEr StuDIES2.2.

This report concerns engineering, layout and geographical position only. It does not address a number of topics, even though they are of equal importance to engineering, as they were the subject of separate consultancy studies. These other studies were in relation to:

the demand model which provides •

transport forecasts;

environmental and sustainability issues;•

the business case Appraisal. •

CommEntary on alIGnmEnt aCCuraCy2.3.

The Scope of Work called for “Outline Designs”.

The geometric alignments were derived using Ordnance Survey mapping, and designed on computer using an alignment programme, “InRail”.

This programme calculated alignments which were then plotted on OS mapping, using a Digital Terrain model (DTm) and Digital Surface model (DSm) at a 5m grid, with a quoted accuracy of +/- 15cm vertically and +/- 43 cm horizontally. The OS 1:2500 data has a horizontal accuracy +/- 50cm. The OS 1:10,000 data does not quote one value for horizontal accuracy, but was created from a generalised and simplified version of the 1:2500 scale mapping. For example, all roads are generalised to a standard width, and building outlines are simplified. The routes as drawn could therefore be (wrongly) viewed as being “accurate” at this level of detail.

The reader will be able to read the drawings and use a scale rule to determine the position of the route in relation to observable features. However, the route alignments are such that they could be moved during further design development. The key question is that, if a particular route were to be taken forward and eventually implemented, then how far away from today’s drawings would

REmIT, REQUIREmENTS AND ASSUmPTIONS2.


SELFRIDGES ELEVATION DETAIL bIRmINGHAm

LONDON SKYLINE

15

that final alignment be. In some cases, the constraints are such that the final alignment could be less than 5m from its shown position; these constraints are particularly prevalent on the approaches to London and the West midlands. In other locations, principally the more rural areas, the route has more lateral and vertical flexibility and could be adjusted to meet emerging constraints.

It should therefore be noted that:

The information contained on the •

drawings is on a feasibility basis;

The drawings show an indicative rail •

corridor and are subject to further study.

The corridor shown does not •

consider utility locations.

The corridor shown does not •

consider ground conditions.

All vertical information is based on the •

OS 5m grid, and interpolated levels.

Any track turnout positions •

shown are indicative.

The rail corridor shown has been located •

to minimise the impact to the environmental constraints identified on the Environmental Features Legend shown on the route plans.

Earthworks outlines are based on typical •

side slopes, and no detail was prepared on other areas needed for such features for environmental mitigation, landscaping etc.

alIGnmEnt DESIGn aSSumPtIonS2.4.

The alignment design carried out as part of the HS2 was based upon the parameters and constraints outlined in the HS2 Project Specification Version 2 (HS2-HS2-020SP-RW-0001). These guidelines for track design are largely based on the TSI, 2002/732/Ec (Technical Specification for Interoperability relating to the infrastructure sub-system), with some input from the relevant sections of the Network Rail Standard, NR/SP/TRK/0049 (Track Design

Handbook) and practices adopted on HS1 and French systems.

It should be noted that whilst the route options that passed Sift 3 comply with the guidelines outlined in the HS2 Project Specification Version 2, earlier options do not as Version 1 of the HS2 Project Specification used different parameters which are non-compliant in relation to the standards mentioned above.

The key geometry considerations made and adopted as part of the design are:

Horizontal Alignments:

max curvature of 10,000m•

maximum cant of 180mm•

max cant deficiency: 100mm up to •

300kph, 80mm above 300kph

max rates of change of cant and •

cant deficiency 55mm/s

All transitions were clothoids •

Track centres: 4,500mm for speeds of •

200kph+, 3,065m at 200kph or less

Vertical Alignments:

max ‘normal’ value of vertical acceleration •

of 2.25%g. Higher values (max 3.25%g for a hollow and max 4.25%g for hump) adopted in exceptional circumstances.

max vertical curve radius of 56,000m •

at 400kph using 2.25%g.

SELFRIDGES bIRmINGHAm


max ‘normal’ gradient of 2.5%, increasing •

to max of 3.5% for exceptional use.

Vertical curves used between two •

vertical straight elements

2sec rule applied to straights between vertical •

curves to account for motion sickness.

Turnouts:

High Speed turnouts (230kph) used a crossing •

angle of 1 in 65 based on a preliminary design provided by Vossloh cogifer;

Slower turnouts in station regions •

based on NR60 Type in NR/SP/TRK/0049 (Track Design Handbook);

All mainline turnouts placed on •

straight sections of track, both horizontally and vertically.

In all but exceptional cases, the design did not use these maximum values. At 400kph, horizontal radii generally used were 8220m, at 150mm cant, with 350m length transitions between elements. It would, for example, still be possible to reduce the radius to 7265m, at 180m cant, with 370m long transitions and still maintain a 400kph railway. The geometry was designed to facilitate future flexibility.

Arup raised queries in relation to several items in the HS2 Project Specification Version 2. The specification stated that the vertical radii should be limited to 40,000m, but, at 2.25%g, 400kph could not be achieved. HS2 agreed that vertical radii could be increased to 56,000m, which would permit 400kph over crest vertical curves at the desired %g value.

tunnElS2.5.

Appendix A is a comprehensive account of the considerations given to tunnelling methods, geometry, appropriate solutions in particular circumstances, and aerodynamic assessments relating to a variety of desired speeds and tunnel lengths.

The range of tunnel configurations considered was as follows:

Twin bored, Single Track Tunnels (with •

cross passages where required);

Single bore, Twin Track Tunnel (with •

or without central dividing wall).

The tunnelling methods considered were:

Tunnel boring machine (Tbm) •

driven tunnels with machine type dependent on ground conditions;

mined tunnels, i.e. tunnel driven without a •

shield, generally utilising Sprayed concrete Lining (ScL) for initial ground support.

For the purposes of this feasibility report, an attempt was made to distil the output of the tunnelling study (Appendix A) to propose a limited number of tunnel cross-sections to be considered for use along the HS2 route.

The length of tunnel would affect the general cost effectiveness of different methods. It was assumed that tunnels above 2km would be likely to be more cost-effectively driven by Tbm rather than mined with ScL support. It was also assumed that, for tunnels less than 2km, there would be no need for a dividing wall in single twin-track tunnel as the train stopping distance is likely to mean that trains on fire would be likely to run through, rather than stop in, tunnels of

17

this length. This assumption was based on North Downs tunnel on HS1.

In general terms, tunnels under London were required to offer 225kph capability, those through the chilterns to offer 320kph, and those in “open country” to offer 400kph. care was taken to ensure that the horizontal and vertical alignments in tunnel locations would not preclude 400kph running should suitable train technologies be developed. The specific solutions are described in the route descriptions.

In summary, the following tunnel sizes were assumed for different line speeds, tunnel lengths and situations:

Length

Speed

225kph

(twin bore,

single

track)

320kph

(twin bore,

single

track)

320kph

(single

bore, twin

track)

400kph

(single

bore, twin

track)

<2km

(Urban)

7.25mID* 8.5mID N/A N/A

<2km (Rural) N/A N/A 12.2mID** 15.1mID***

>2km 7.25mID 8.5mID N/A N/A

* mID means “meters, internal diameter”.

** 11.6mID for tunnels less than 400m long

*** 11.6mID for tunnels less than 300m long

Appendix b presents a summary of tunnel ventilation requirements. At

this stage, the tunnel sizes assume that no ventilation shafts are present.

However, the costs include shafts (for emergency intervention), at a spacing

of approximately 2km. This is the most conservative scenario.


GEotECHnICal aSSumPtIonS2.6.

The geological materials between central London and the West midlands consist of a wide variety of sedimentary strata from Palaeogene to Triassic age, overlain in many places by superficial deposits of glacial and fluvial origin. The youngest, Palaeogene materials, are mainly clays (London clay Formation and Lambeth Group). These overlie the Upper cretaceous chalk Group, which largely comprise a weak pure limestone. This material forms the higher ground of the chiltern Hills. North-west of the chiltern Hills, the HS2 route would traverse a broad flat vale underlain by Lower cretaceous and Upper Jurassic clays (Gault clay, Kimmeridge clay Oxford clay etc). However in the Aylesbury area this flat topography is broken up by a series of hills capped by Jurassic Portland and Purbeck strata, and Lower cretaceous Wealden Group strata. To the north west of the clay vale, the HS2 route(s) would traverse undulating topography underlain in turn by middle Jurassic Great and Inferior Oolite Group limestones and clay, Lower Jurassic clay and Triassic mudstone and sandstone. In Warwickshire, the route(s) would locally cross onto Permian and Upper carboniferous mudstones and sandstones where they locally protrude through the Triassic sediments. There were no significant geotechnical issues. A representative geotechnical map is presented in Appendix c.

19

RUGBY

THAME

LUTON

LONDON

DIDCOT

OXFORD

RUISLIP

RUGELEY

EVESHAMBANBURY

WARWICK

BEDFORD

READING

NUNEATON

TAMWORTH

BICESTER

COVENTRYSOLIHULL

LICHFIELD

STEVENAGE

KETTERING

ST ALBANS

AYLESBURY

BUCKINGHAM

BIRMINGHAM

CIRENCESTER

NORTHAMPTON

HIGH WYCOMBE

MILTON KEYNES

STOW-ON-THE-WOLD

STRATFORD-UPON-AVON

Proposed Route

Tunnel

Viaduct

© Crown copyright and database right 2009. All rights reserved. Ordnance Survey Licence number 0100049190.

Topography (m)< -200 - -200

-190 - 0

0.01 - 10

11 - 20

21 - 30

31 - 40

41 - 50

51 - 60

61 - 70

71 - 80

81 - 90

91 - 100

110 - 120

130 - 140

150 - 160

170 - 180

190 - 200

210 - 220

230 - 240

250 - 260

270 - 280

290 - 300

310 - 320

330 - 350

360 - 400

410 - 450

460 - 500

510 - 550

560 - 600

610 - 640

0 10 20 30 405Km

TOPOGRAPHIc mAP


StruCturES aSSumPtIonS2.7.

Appendix D sets out the structures issues, particularly relating to longer structures with repeating spans, and provides parameters for route definition and costing. Key issues are summarised below.

Issues2.7.1.

There should be opportunities to achieve construction speeds and economies due to standardisation and investment in special equipment, typically with whole spans being lifted in one to create viaducts. While it would not be necessary for all viaducts to have the same span lengths, it is likely that construction equipment would be passed from site to site, and the size of this equipment would be driven by the largest span.

In general, steel bridges are significantly noisier than concrete bridges, but they can be designed to meet specific noise limits. There is limited experience in this field. It is likely that the cost advantage of steel would be lost on a very large project, and the basic material costs for concrete solutions are likely to benefit from factory-like on-site pre-casting.

It is anticipated that the major structures for HS2 would be built with continuous rails and discontinuous decks pre-cast on site as full span concrete units. Where the rail would be more than about 35m above ground, continuous, push-launched concrete structures may be used, with joints in the rails at about 800m spacing. In either case, the construction would take place in safe working conditions within a factory-like environment on site.

ballast or slab-track remains a debate: France believed in ballasted track and all its benefits, and Germany believed in slab-track, and a different set of benefits. ballasted track is heavier than slab-track but this may not be an issue. Slab-track is shallower than ballasted track, but this may not prove to be an issue.

Overall Conclusion2.7.2.

The initial designs assumed a structure rising 1,200mm above the underside of the track envelope, giving an overall structural depth below rail level of about 3.5m. It was assumed that the viaducts would have ballasted track, continuous rails and spans of up to 50m. It is also likely that structures would be built in pre-cast concrete with one half-joint per span. ConStruCtaBIlIty

Issues of constructability were considered in determining the route alignments. These matters were of particular concern on the stations, and the tunnelled sections of the route, and the outcome of the considerations are reported in the appropriate geographical section.

On the open-country route elements, it was assumed that there would typically be a 10m construction width requirement outside the permanent earthworks outlines, as well as additional areas for site compounds, contractor’s materials storage, laying-out areas for S&c units, and working space around major structures etc.

EnvIronmEntal mItIGatIon2.8.

Environmental mitigation will require areas of land outside the purely engineering footprint of the scheme; and only this engineering footprint is shown on the present drawings.

For major projects such as this, significant earthworks, planting areas, balancing ponds and replacement facilities can be anticipated. The present drawings do not show all these areas, and the reader of the drawings should bear in mind that significant extra areas of land will be needed.

more work on these issues is needed for the chosen route.

21


23


Geological map

25

SuPPortInG rEPortS3.1.

A number of free-standing reports were prepared by Arup on railway operational issues in order to support its infrastructure design decisions, or to provide information for HS2 Ltd’s train service planning work, or to stimulate debate on network-wide issues.

The most significant findings were in respect of journey time modelling, and the results of this analysis are reported below.

vISIon moDEllInG for SECtIonal 3.2.

runnInG tImES

The train operations simulation software, VISION was used to undertake journey time modelling. The modelling software simulates the minimum journey times possible with the specified route infrastructure and maximum permissible speeds. .

In britain, the normal process for developing realistic (or timetabled) journey times is to calculate minimum unrestrained journey times and then to add a time allowance to cover for variations in day-to-day performance, pathing, and minor perturbations. In France, for high-speed routes, the maximum permissible line speeds are lowered, and the lengthened journey times simulated. This gives a margin for day-to-day variations and incidents. It is understood that this “French” timetabling approach has been used on HS1, which has led to criticism that the available line speeds are not utilised, and the route not used to its full potential. The journey time results presented in this report are derived from this factored speed approach.

It was assumed that there would be a station dwell time of 2 minutes, which would be of some significance when stops at both Old Oak common and birmingham Interchange are considered. These actual dwell times, plus the acceleration and deceleration impacts, could typically add 3 – 5 minutes to running times for each station stop.

journEy tImES BEyonD HS23.3.

To allow journey times to WcmL destinations north of Lichfield to be calculated, the models were extended over the WcmL to Rugeley North Junction

Although the HS2 proposal ends at Lichfield, Rugeley was chosen as a timing point north of the tie-in. The existing West coast main Line scheduled times to Rugeley (for a Pendolino train with no stops south of Rugeley) are typically 67 minutes. The VISION models for HS2 give a non-stop time of about 44 minutes, so trains would gain about 23 minutes by using HS2.

journEy tImE rESultS 3.4.

The journey time results are presented in each route chapter.

RAILWAY OPERATIONAL AND NETWORK ISSUES3.


CaPItal CoSt mEtHoDoloGy4.1.

Introduction4.1.1.

The capital cost of HS2 will be dominated by civil engineering costs, particularly stations and tunnels. The remainder of the civil engineering elements such as structures and earthworks will be next in significance. “System” costs for track, electrification and train control systems will be in the order of 25% of the total cost of an open-country section of route (i.e. excluding stations and tunnels), but would largely be fixed regardless of the route selected; it would be the civil engineering costs that would drive the variations between options. Attention was therefore focussed on obtaining up-to-date and meaningful quantities and civil engineering rates.

Civil Engineering Rates Database4.1.2.

Arup has developed a database of civil engineering unit rates from recently-tendered contracts for linear civil engineering schemes. For any item, 8 rates were available, and the lowest and highest of these were set aside from the analysis. The remaining 6 were averaged to produce a mean value, but the remaining outliers (original rates 2 and 7) were retained for use in a risk profile basis. The spread of rates was used statistically to derive risk-based cost profiles.

From these individual item rates, composite rates were built up for measurable items, for instance, cuttings. An amalgamated rate was therefore derived per cubic metre of cutting, aggregating individual rates and making assumptions of side slopes, top soil depths, percentage of re-use etc. The composite rates were then used alongside items of measure from the engineering drawings. The alignment model was used to derive earthworks quantities; other items were measured as linear measures, or other appropriate measure. This process was repeated for the entirety of the rates database, to allow extraction of quantities. Sensitivity test were conducted on the variable parameters (such as side slopes) to allow an understanding of the sensitivity of costs.

General Route Costing Methodology4.1.3.

Each route was sub-divided into geographical sections. A spreadsheet was produced for each of these sections, allowing quantities to be input from the engineering drawings. The unit rates were drawn from the embedded data as described above. The spreadsheet then allowed the user to specify a number of geographical sections to be added together to produce route totals (for HS2 Ltd’s Preferred Route and the remaining two other options).

Tunnelling Costs4.1.4.

Tunnelling costs were built up from generic and historic data.

There was, however, insufficient detail to derive firm costs, as these will ultimately depend on data which is not available at present. There will not be a clear link between diameter and cost, nor would costs be pro-rata to length. The cost per metre would depend on:

ground conditions; •

the construction method;•

the portal structures (some of which are •

tens of metres in length, while others would be almost a kilometer long);

cross-passages or other safety measures;•

the future cost of Tbms, their number, •

potential reuse, write-off cost, the client’s procurement strategy, and the contractor’s construction strategy;

vent shafts (or their absence).•

Preliminary cost estimates were therefore made relating to measurable parameters such as Tbm costs, tunnel circumference, spoil volumes etc.

Although the costs provide an order of magnitude, they are based on an assumed construction and are subject to review/verification. It is to be noted that the rates include for the base cost of tunnel construction and associated works only in normal ground conditions. They do not include for any rail infrastructure costs and are subject to the normal on-cost adjustments.

cAPITAL cOSTING AND RISK ASSESSmENT 4. mETHODOLOGY

27

The cost calculations include an allowance for pressure relief shafts; the aerodynamics calculations assume no pressure relief shafts. Therefore a worst-case combination was assumed, for a tunnel sized for aerodynamics without relief shafts (i.e. largest cross-sectional area) with the additional cost for relief shafts. However, because there are many uncertainties in the costing assumptions, it was appropriate to retain this element of conservatism.

Station Cost Estimates4.1.5.

capital costs for stations were estimated using a combination of:

civil engineering rates (as described above). •

These would typically be used to determine the cost of the civil engineering components, i.e. demolition, earthworks, slab construction, walls, road construction, drainage etc.;

rail system costs. costs of track, switches, •

OLE and signalling as determined in the calculations in the spreadsheet;

station building costs. costs of platforms, •

canopies, concourses, station facilities etc. These costs were derived, where possible, from historical information of similar station schemes.

In all cases, cost information, calculated or derived, was checked against publicly available data from cost data reference books.

For works involving alterations to existing stations and elevated stations, works at cTRL St Pancras were used as a guide, but particular note was made of the issues at each site, including access to the London Underground. Similarly, for at-grade stations, cTRL Ebbsfleet Station was used to benchmark costs. Additions and subtractions were then made to reflect the particular characteristics of each site, particularly in terms of depth below ground, the positioning of the track and concourse levels, and the road access requirements. For deep “cavern” stations, estimates were derived from the tunnelling requirements, allowing for the approach tracks and platform requirement.

Train Control System Cost Estimates4.1.6.

The approach to estimating the cost of the train control system used two independent methods, the results of which were then compared, reconciled and used to construct a very simple cost model.

In method A, Network Rail’s signalling cost model was used intuitively to derive a cost firmly based on the proposed HS2 route length and track layouts.

In method b, published cost estimates and reports from European projects to derive comparators were used.

Network Rail estimates the cost of re-signalling schemes at an early stage using the ‘Signalling Equivalent Unit’ (SEU) cost model. Each signal and point end, for example, on a scheme plan is treated as 1 SEU. The total SEU count is multiplied by the current benchmark SEU cost (roughly £250K) to derive an all-in cost of a scheme.

This model was adapted intuitively to derive an SEU count from features that would exist in a cab-signalled ERTmS/ETcS railway. Point ends were still counted as 1 SEU, but fractions of an SEU were used for route nodes (i.e. non-passable marker boards where routes must be set) and section nodes (i.e. passable marker boards on plain line). An estimate was made of the number of conventional signals that would be used at interfaces to the historic network.

method b used publicly available cost data, which varied enormously (from £5K to £130K per route-kilometre) and it was not always possible to determine what was included in the figures: the most significant unknowns were as follows:

Were all the infrastructure manager’s •

costs included, or only the signalling supplier’s contract value?

Was GSm R included?•

In one case, it was not clear whether •

costs were normalised per single-track-km or per route-kilometre.


In all cases, however, it was possible to exclude the cost of rolling stock fitment.

method A yielded a cost of £120m for a typical route. considering the 180 route-km of HS2, the typical or mid-range benchmark figures of method b fell between £16m and £130m. It was therefore decided to treat the results of method A as an upper limit, particularly because the SEU cost model and the top-end benchmark cost are both set in the context of migrating an existing, operating railway to ERTmS/ETcS. by contrast, HS2 would see ERTmS/ETcS applied as a mature technology onto a purpose-built railway without any of the inconvenience of keeping existing train control systems in operation during the installation and commissioning phases. It is therefore expected that eventual costs would be roughly half the method A figure, or perhaps as low as one quarter.

Given that costs of this order make up a small proportion of the whole, it was not felt necessary to require cost estimates to be derived from a detailed SEU estimate. SEU counts were therefore apportioned in the model to the two main drivers of train control costs: point ends and route length. This resulted in the following cost rates to be used in capital cost estimations.

Rate High Expected Low

£K per route-km 310 155 80

£K per point end

500 250 125

Electrification / OLE Cost Estimates4.1.7.

Arup has some data on electrification costs, albeit not as comprehensive as the civil engineering unit rates discussed above. Also, this data is largely derived from electrification of existing lines, with their attendant issues of structures clearances, possession working and many other issues not relevant to new construction in a green-field site.

Network Rail has only very recently published an Electrification Route Utilisation Strategy ( RUS),

and this contains data on electrification costing, but again obviously related to conversion of existing lines.

What is Included in the Cost4.1.8.

Each of the routes was broken down into the generic headings of:

P/Way. Unit of measure: per metre. •

costs included are rail,sleepers, ballast, cess walkway, track drainage and high security fencing;

Switches and crossings. Unit of measure: •

per number for a range of speeds;

OHLE. Unit of measure: per •

metre. costs include OLE, support structures and power supply;

Signalling (Train control systems). Unit of •

measure: per route-km and number of point-ends. costs include all signalling and communication requirements.

Stations. Unit of measure: per location. •

costs include civil engineering works, station buildings, station facilities, track, switches, OHLE, train control systems and utility diversions. costs will also include any station specific requirements, i.e. connectivity with other stations, car parking facilities, construction difficulties etc;

Earthworks. Unit of measure: per m3. costs •

include site clearance, earthworks, soiling, seeding and small structures/accommodation bridges etc. The scope of earthworks measured under this section is confined to the P/way only. All other earthworks (stations, roads, tunnels and structures) are included in the particular unit cost;

Retaining Walls. Unit of measure: per m2 of •

total face area. costs include associated earthworks, concrete, formwork, reinforcement, back of wall drainage and finishing works;

Structures. Unit of measure: per m2 of •

total deck area. costs include associated earthworks, concrete, formwork, reinforcement, pre-cast units, structural steelwork and finishing works;

29

Tunnels. Unit of measure: per metre. costs •

include excavation, tunnel lining, cross links (dual tunnels), shafts and m&E. Separate allowances were made for establishment (reception pits, segment fabrication yard, mobilisation and demobilisation) and portals. Excavation assumed the cost of providing Tbm, 24/7 earthworks operation, earthworks disposal (not included in normal earthworks) and all ancillary considerations (unforeseen ground conditions, dewatering, ground investigation, ground monitoring etc.)

Highways. Unit of measure: per m2 •

of surfacing area. costs include site clearance, fencing, vehicular barriers, drainage, earthworks, pavement, kerbs, footways, signs, lighting and small structures/accommodation bridges;

Utilities were priced as a percentage allowance •

(typically 3%) of the base construction cost for those links considered to be at some risk of conflict with local services

Additional items. This was used to allow for •

items considered not to be adequately covered by the items above, e.g. diversion costs, rebuild works, multi-storey car parks etc.

The summation of the above was defined as the “base construction cost”. Stageworks costs were captured by multiple measures of the quantities of track, signalling and OLE systems.

To this cost was added:

contractors on-costs (Prelims, OH & Profit);•

Site Supervision (client);•

Testing and commissioning;•

Training;•

Spares.•

This total was defined as “construction cost + on-cost”

To this cost was added:

construction Risk. These risks are those •

identified at the risk workshops pertaining

to particular links and are expressed as a probability and a three point estimated value;

Ancillary Items. Refers principally to •

environmental mitigation typically added at 3% of base construction cost (although certain links include higher percentages to reflect sensitivities);

compensation. HS2 will provide this data.•

The summation of costs to this point was defined as “Total construction cost”

HS2 costs were then added, including:•

HS2 Project management;•

Design including consultancy •

charges (Legal, Advisory etc.);

Possession/Isolation management. •

Typically 1% added to specific links;

RImINI costs. Typically 1% •

added to specific links;

TOc compensation / Schedule 4 •

charges (applicable only to a few links). Typically 8% added to specific links;

Topo/GI surveys. costs added in at •

a rate of £150,000 per route km;

Statutory process charges: HS2 •

Ltd will be providing this data;

Route Risk allowance. These risks were those •

identified at the risk workshops pertaining to particular routes and were expressed as a probability and a three point estimated value; refer to the separate risk schedules included in the pricing document.

The following costs were NOT included:

Price Escalation Allowance;•

Land Acquisition. •

consents costs•

Rates and Prices 4.1.9.

All costs are expressed in Q3_2009 prices.


rISk aSSESSmEnt mEtHoDoloGy4.2.

Introduction4.2.1.

An assessment of risk was completed for each route. This identified risks at both route and link level using a monte carlo evaluation of probability and three point estimates. The assessment was originally conducted as an “add-on” exercise to the base construction cost calculated as described above. The tables below provide a summary of those original evaluations carried out as a separate exercise.

A decision was subsequently made to include the risks within the total body of the route estimates – the route summaries present both whole route and link risks.

PRObabILITy Of

OCCuRREnCE (P)IMPaCT On THE PROjECT (I)

Scale Range Value Scale Value

Rare 0 – 5% 1 Insignificant 1

Low 6 - 20% 2 minor 2

medium21 -

50%3 moderate 3

Likely51 -

80%4 Significant 4

Almost

certain> 81% 5 Serious 5

Risk Identification4.2.2.

A series of three risk workshops was held. The aim of the first was to identify a preliminary list of risks to cAPEX, OPEX, revenue streams, viability, programme and HS2 reputation. A list of guidewords was used to prompt risk identification.

Workshops 2 and 3 focused solely on cAPEX risks and estimating uncertainties, and used an alternative risk identification technique. Each route section was reviewed in turn to consider uncertainties associated with the work scope, which could result in a different cost to that assumed in the base cost estimate(s). All risks were recorded in the project Risk Register (Appendix F).

Risk assessment 4.2.3.

Only cost risks, as measures of risk exposure, were assessed. Table 4.1 was used to inform probability assessments; the qualitative Scale (see column 1) of quantitative Range (see column 2) being used to guide the Value (see column 3) to be recorded in the Risk Register.

Table 4.1: Risk classification Scheme

31


Quantitative Cost Risk analysis (QRa)4.2.4.

All cost risks, regardless of exposure, were modelled. These risks included:

Direct cost risks;•

Programme delay cost risks, and•

cost estimating uncertainties.•

Three-point estimates (i.e. minimum, most likely and maximum cost values), assuming the risk occurs, were agreed with workshop attendees. At this stage, estimates were not made relative to a base cost plan. The justification for three-point estimates is recorded in the risk register.

Probability and severity distributions for risks and uncertainties were described in @RISK by binomial and PERT distributions respectively. The Risk collect @RISK function was used as an additional argument to the distribution functions, so that only functions identified by Risk collect were displayed in the simulation results and sensitivity analysis.

Output cells, using the Risk Output function, were used to combine the simulation results from all the modelled risks for each route. @RISK for mS Excel was used to simulate the models. 5,000 iterations were run using the Latin Hypercube sampling method.

Risk assessment Results4.2.5.

The QRA results for each route are presented in the relevant route chapter.

The results are presented in terms of key output statistics, a cumulative cost risk distribution graph and a tornado chart, which illustrates the sensitivity of the results to individual risks within the QRA models.

oPtImISm BIaS4.3.

The issue of the application of Optimism bias is being addressed by HS2 Ltd, using the results of this risk analysis to inform any application of that principle.

33


IntroDuCtIon5.1.

Route 3 is HS2 Ltd’s Preferred Route.

It would run from an expanded London Euston station to a new station in central birmingham and it would also connect to the West coast main Line (WcmL) near Lichfield.

There would be a new station at Old Oak common. The route would then run via the Old Oak common to West Ruislip corridor, before passing through the chilterns near Great missenden and Wendover. It would then pass to the South-West of Aylesbury and east of brackley, before passing between Kenilworth and coventry. It would pass east of birmingham, with a new station near birmingham International. The route would continue north to pass east of the belfry, and would join the WcmL west of Lichfield.

A spur from this route, in the coleshill / Water Orton area, would link towards central birmingham, to a new station near Fazeley Street, that would open out onto moor Street, with access to New Street Station and the city centre.

There is a full set of detailed engineering drawings to accompany the more general maps presented in this chapter.

ROUTE 35.

35

!

!

!

!

!

!

!

!

!

Birmingham

Wendover

Amersham

Brackley

London

Ruislip

Warwick

Bicester

Solihull

Aylesbury


Route 30 9 184.5

Km

LINE OF ROUTE 3


EuSton StatIon5.2.

Introduction5.2.1.

The specification for the London Terminal for HS2 required a facility with 10 platforms, 415m in length to receive and despatch up to 15 trains per hour carrying approximately 1,000 passengers each.

Key parameters for selection of an appropriate site were, therefore, the size of site available (to include space for a high speed throat) and dispersion of passengers.

Numerous sites were investigated from existing stations through development sites to currently occupied sites and the preferred option selected at Euston. No existing London Station could accommodate the length required for platform and throat, but Euston offered the best opportunity to achieve the desired provision.

Existing Station 5.2.2.

built originally 150 years ago, Euston was substantially refurbished in the mid 1960s with further major throat modifications undertaken about 10 years ago.

The existing station occupies a site approximately 180m wide, providing 18 platforms served at their southern end by ramps from a raised concourse and service bay beneath. The longest platforms are in excess of 300m which, together with the concourse, gives an overall station length of the order of 420m.

The approach to the station from the north comprises 6 tracks from camden Junction descending camden bank to a track fan starting beneath Hampstead Road bridge. The vertical alignment falls from the Park Road tunnel to the north at approximately 1.5% to the Hampstead Road bridge, incorporating a ‘dive-under’ and then rises to the station about 1.5m. In plan, the station is offset from the approach alignment, necessitating a track fan located on reverse curves (S-bend) and curved platforms; this significantly constrains both throat design and operational flexibility.

Hampstead Road is a major north-south highway linking Tottenham court Road to the south to camden in the north. At the intersection with the railway, it is dual carriageway. This bridge provides minimum clearance for the rail and overhead line equipment beneath.

Passenger dispersal is primarily via London Underground, with direct access to Northern Line charing cross branch, Northern Line city branch and Victoria Lines, and indirect access to metropolitan and circle Lines via the adjacent Euston Square station. The LUL concourse currently handles approximately 7,000 passengers per hour at peak. It is situated beneath the existing concourse and is generally recognised to be too small for current demand.

The constraints surrounding the Euston site include:

Euston Square Gardens to the south (part •

of the bloomsbury conservation Area);

Listed buildings to the south-•

east and south-west;

Eversholt Street and melton Street •

along the east and west façades;

St. James’s Gardens on the west side;•

mornington crescent and other residential •

areas to the east of the throat;

Residences as part of the crown Park •

Estate on the west of the throat.

The existing station provides 18 platforms receiving, at peak, 18 trains per hour, primarily for Virgin West coast and London midland Trains.

37

EUSTON STATION - EXISTING cONcOURSE AND PLATFORm LEVEL


General Description5.2.3.

The proposal would be for a new station comprising 10 HS2 platforms (5 islands) alongside 14 classic platforms (7 islands). Two of the classic platforms (one island) would also have the facility to receive ‘hybrid’ HS2 trains.

The High Speed station was designed to receive up to 15 trains per hour with, typically, 1,000 passengers each. This would align with a 30-minute dwell time and 75% occupancy, matching the 3-minute headway and 75% occupancy specified for the two track railway as a whole.

The classic station would be designed to meet current service patterns (excluding the Watford Dc 3 trains per hour), for which 14 platforms would be sufficient. Provision would be made for future IEP services which are proposed to be longer trains.

Due to the HS2 platform length, the new platform level would extend southwards to the northern edge of Euston Square Gardens and would necessitate demolition of the existing office blocks immediately south of Euston Station. The Grade II* Listed building at the south-west corner of the site would be retained.

A new concourse for HS2 and classic services would be provided above the platform level and a new LUL concourse provided below platform level. This new concourse would be at approximately existing ground level and would provide permeabillity for pedestrian and vehicular movements.

The total reconstruction of the station would enable optimisation of platform and throat to maximise facilities for both HS2 and classic services. However, it would be necessary to extend the footprint of the station across melton Street to cobourg Street on the west side to enable the development of a high speed throat, and to create track access to the wide High Speed platforms, given their increased length.

The Grade II* Listed building on the corner of melton Street and Euston Road would be retained.

39

EUSTON STATION PROPOSED STATION FOOTPRINT


Provisions for HS25.2.4.

alignments and Permanent way

The HS2 platforms would be located on the west side of the station to enable provision of both platform length (415m) and a high-speed throat (100kph to 85kph in the track fan).

The two tracks from Old Oak common would emerge from a new tunnel portal immediately south of Park Road to the west of the four remaining classic tracks. A vertically separated junction would then be formed between mornington Street bridge and Granby Terrace bridge to provide two pairs of tracks into the station.

The west pair would serve the 4 platforms along the western edge. Due to space constraints, the up and down tracks would briefly share a sloping alignment immediately north of the track fan to enable provision of a diamond crossover, essential for operational requirements.

The east pair would serve the eastern 6 high-speed platforms, together with the ‘hybrid’ platform. It was assumed that the hybrid platform would essentially serve classic services and, therefore, a flat crossover of the HS2 and classic fans would be acceptable.

To enable the specified Gc gauge, the HS2 lines would need to be lower than the present track levels at Hampstead Road bridge (or the bridge would need raising) by approximately 1.5m. The existing bridge has already been raised above natural road level and is constrained to serve mornington crescent and street-facing properties to the north-west, and a series of street-facing properties along its south-west pavement. In the light of the general station design, it was decided not to raise the road, even though Hampstead Road bridge would require complete reconstruction for its entire length. The track lowering would require the new western retaining walls to be higher than the existing.

The track fans would start north of Hampstead Road bridge. Their complexity and the

requirement to link with adjacent classic track fans would require all fans to be on one plane. It is therefore desirable, both from a station planning perspective and to facilitate throat design, to continue the track level beneath Hampstead Road bridge horizontally through the station. This would provide a track level of 16.5m above Ordnance Datum (OD). current track levels at Hampstead Road bridge are at approximately 18.5mOD and at the station 20mOD.

The tracks would extend approximately 100m further south than those of the existing station which, allowing for buffer stops (25m) would take the platform deck to the northern edge of Euston Square Gardens.

Platforms

The 10 HS2 platforms (5 islands) would be 12m wide with a maximum reduction to 9m over the last 70m at the country end. The ‘hybrid’ platforms would be 12m wide with a similar taper to 9m. Where platforms would be curved, a minimum curvature of 1000m would be used

Access to the HS2 and ‘hybrid’ platforms would be from a paid zone of the concourse above, via 6 banks of 2 escalators. These could be arranged in pairs (i.e. both up) for full length trains most, or opposed (i.e. one up, one down) for half length formations.

The escalators would clear the platforms in between 2 and 3 minutes, which would compare well with the specified 3-minute headways.

Access to platforms for servicing has yet to be developed. It is anticipated that servicing would be from the north of the station to avoid conflict with passengers, possibly utilising the bT Depot Site (north-east corner) to access bridges or underpasses and ramps to platforms at their country end.

41

EUSTON STATION PROPOSED TRAcK ALIGNmENT


Provision for Classic Services 5.2.5. alignments

The classic platforms would be located on the east side of the station adjacent to HS2 platforms. being shorter, the platforms could be accommodated on the outside of the reversed curves, still minimising their curvature (minimum radius 1000m).

The classic station would be served by 4 tracks from camden Junction, passing under Park Road in tunnel as the existing four tracks. minor track modifications in the camden Junction area would enable the approach tracks to be paired (up, down, up, down) before reaching the two track fans beneath Hampstead Road bridge

South of Primrose Hill tunnels, the existing 4 WcmL tracks would form a Slow line pair to the

east at camden bank, with a Fast line pair to the west. The existing dive-under, which carries the slow lines under the Up Fast, would remain, though would not have a particular use in normal operation. The existing underpass for northbound services from the presently low-numbered platforms would be lost to the new HS2 lines. The platforms would be split into 6 (3 islands) for the east-west fan and 6 (3 islands) plus 2 (1 island) ‘hybrid’ platforms for the west fan. There would be no need for the provision of vertical separation for classic lines.

As noted, the vertical track alignment would descend at approximately 1.5% from Park Road to Hampstead Road bridge (the start of the fans) and would then run horizontally through the station to buffer stops adjacent to Euston

PARK STREET TUNNELS - EXISTING ScHEmATIc TRAcK LAYOUT

PARK STREET TUNNELS - PROPOSED ScHEmATIc TRAcK LAYOUT

43

EUSTON STATION PROPOSED PLATFORm LEVEL


Square Gardens. The ‘hybrid’ platform would also be served from the east-west HS2 track via flat crossings.

The horizontal throat and station alignment at the same level as HS2 would facilitate the design of the fans and the interaction of HS2 and classic lines for the ‘hybrid’ platforms.

The lowered alignments would require excavation of the throat by approximately 1.5m north of Hampstead Road, increasing to 3m down the length of the station. civil works to existing retaining walls to the north would be augmented by new retaining walls along the station edge (Eversholt Street).

The overall track and platform layout is shown schematically alongside.

Platforms

A study of platform occupancy, using existing service patterns, was carried out. A further study then was undertaken to establish the number of platforms needed for the services that would remain on the classic side of the station for the remaining WcmL services. This would need both operational plans and forecasts, and HS2 demand forecasts, to establish how much of the existing traffic would be transferred to HS2. This work is, it is understood, currently being undertaken by HS2 Ltd.

The platforms provided would be 6 (3 islands) at 260m long for conventional 12-car trains, 6 (3 islands) at 320m long, in anticipation of the longer IEP services, and 2 (1 island) at 415m long for the ‘hybrid’ platform. All platforms, apart from the ‘hybrid’ one, would be 10m wide, tapering over the last 70m to 8m minimum. All platforms would have some degree of curvature (minimum radius 1000m). consideration will have to be given to the retention of the facilities for sleeper services.

The platforms would be accessed from the concourse above via 4 banks of 2 escalators each. This would facilitate platform clearance

in between 2 and 3 minutes which would align well with the potential minimum headways of 2 minutes.

Access to the platforms for servicing has yet to be developed, but it is anticipated it would be from the north, utilising the bT Depot site (north-east corner) to access via bridge or underpass and ramps to the country end of the platform. This would avoid conflict of servicing and passenger movements.

Concourse Level [Rail] 5.2.6.

Euston Station currently handles a maximum flow of about 7,000 passengers per hour across the concourse to the underground at peak periods. The introduction of HS2 services may involve up to 10,000 passengers per hour needing to access the Underground. This would increase the pressure on concourse space for both Rail and Underground users by a factor greater than 2.0. (This is similar to current King’s cross/St Pancras passenger flows). It is anticipated the Old Oak common Interchange will reduce pressure on the Victoria Line.

The proposed concourse would be located above the platform deck level and would be integrated with the podium circulation of any future ‘air-rights’ development. The space would be open plan in the continental style, providing generally unconstrained public access. Gated bridge areas would provide access, via escalators, lifts and stairs, to both HS2 and classic platforms below. The track level would be 16.5mOD with concourse level above at approximately 24mOD, which would be compatible with the Euston Road level of 23.5mOD and cobourg Street level of 25mOD. Thus the concourse would be effectively at ground level providing a high degree of permeability in all directions.

The design intent was to create a spacious, active, environment for public, residents and passengers alike, whilst retaining a clear identity and focus for the HS2 station.

45

EUSTON STATION ScHEmATIc LAYOUT OF HYbRID, cLASSIc AND HS2 TRAcK ALIGNmENTS


EUSTON STATION PROPOSED cONcOURSE AND PLATFORm LEVEL

47

The concourse would be perforated to provide natural light through to platform level and enhance the overall volume of the station.

Access to the concourse would be from Euston Road (and Euston Square Underground Station) to the south, cobourg Street to the east (possibly incorporating taxi provisions) and Eversholt Street to the west (with provision for buses, taxis and possible future trams). There would also be a facility to the north of the concourse level to provide a transverse route for buses and taxis. This would be developed at a future design stage.

Direct connections to Euston Square Station (metropolitan and circle Lines) and to St Pancras station were not included. However, both were the subject of studies in the past by others in the form of subways.

EUSTON STATION cIRcULATION DIAGRAm


49

EUSTON STATION - VISUALISATION OF PROPOSED STATION ENTRANcE


51

EUSTON STATION -VISUALISATION OF PROPOSED STATION cONcOURSE ( HS2 SEcTION)


LuL Concourse5.2.7.

As noted above, the passenger flow through the LUL concourse would more than double. The existing concourse space beneath the existing rail concourse would be taken by the platform level extension, necessitating its reconstruction. The new concourse, to be provided below track level, would extend from the existing footprint, both north and west, to provide 2 additional escalators to each of the Northern and Victoria lines, effectively doubling the platform access.

A zone would be reserved between classic and HS2 platforms to provide vertical circulation for the new rail concourse above track level to the new LUL concourse below track level. This would be by escalator, lift and stairs. It is anticipated that interchange between the two concourse levels would be achieved locally to the points of access to HS2 and classic platforms to minimise pedestrian movements and resulting conflicts. This central zone would also facilitate replacement vent shafts to the Underground lines.

General Site Development5.2.8.

It is anticipated that the site would be developed by others as part of an integrated scheme. No master planning or urban planning was carried out as part of this study. It is anticipated that this would become part of a future study covering planning gains, funding, etc. The extension of the station footprint and throat to the west would displace five residential blocks and would reduce St. James’s Gardens.

Some potential solutions for where displaced employment, residential and open space might be relocated is shown alongside. Any future development at or around the station would be subject to consultation and masterplanning in the future.

53

EUSTON STATION AREA DIAGRAm OF POSSIbLE RELOcATIONS


Constructability5.2.9.

Initial studies were carried out on methods of constructing the station. Key objectives were:

maintain rail and underground operations •

as far as reasonably possible (displacing the minimum number of services);

To minimise land take which recognises •

the need to replace residential accommodation on site in advance of its demolition due to the extension of the station and throat footprints westward.

The provisional construction plan would be:

Phase 1 – Enabling Works (No •

station closure) (18 months)

Demolish buildings along west –

side of station in extension zone to enable development above

build new station structure. –

Phase 2 – First Station closure – build •

new classic Platforms 1-6 (24 months; 12 months overlap with Phase 2)

Demolish and remove station (platforms –

and concourse) platforms 1-8 along east side (platforms 9-18 remain active);

build new low level LUL concourse –

with new platform access facilities;

build new east side platform deck –

tracks including eastern throat. (Note: This would require the modifications at camden Junction to be carried out);

build the new concourse level –

along the east side.

Simultaneously construct the new –

western concourse deck structure, the new residential accommodation and commence west side commercial air-rights development.

Phase 3 – Second closure •

of Euston.(24 months)

Demolish and remove classic station –

platforms and concourse, platforms

9-14, the central zone (new platforms 1-6 and platforms 15-18 remain active);

Replace existing LUL concourse –

with new concourse (Phase 3 to 4 concourse join to double the capacity of LUL passenger facilities);

build new classic platforms 7-16 –

(includes ‘hybrid’ platform) together with second classic throat;

build new central rail concourse zone; –

commission the remaining classic platforms. –

The classic station is now complete.

Simultaneously the commercial air- –

rights development may be pursued over the Phase 2 site and works can start on demolition of the residential blocks north of the Phase 1 site.

Phase 4 – Final closure of Euston.(24 months) •

complete demolition of west –

side throat zone;

complete demolition of existing –

station platforms and concourse;

construct new track fans, grade –

separation and all HS2 platforms;

construct remaining concourse zone; –

commission new HS2 station. –

Typically there would be a rearrangement –

of the approach throat layouts at each successive release of new platforms, with “double-handling” of all approach trackwork, signalling and OLE. The development above would then need completion.

Detailed planning of the throat and any –

temporary throat design has yet to be addressed. Similarly, detailed planning of the replacement of Hampstead Road bridge has yet to be addressed.

Total construction Period - 78 months•

It is recognised that the Euston works would require stageworks involving multiple handling of track, signalling and OLE equipment. The multiplicity of these changes was captured in the cost estimates.

55

EUSTON STATION - cONSTRUcTION SEQUENcE - PHASE 1





EuSton to olD oak Common5.3.

Overview5.3.1.

From the Euston portal, the route would be in tunnel to Old Oak common. The route would consist of twin 7.25m internal diameter tunnels, connected by cross-passages at 250m intervals. This minimum diameter of 7.25m would theoretically allow speeds up to 225kph, but these might not be achievable given the acceleration and deceleration rates of the reference train used in the design. The maximum speed achieved in operation along this length would depend on the acceleration and deceleration rates chosen for operation, timetabling constraints and whether all the trains would stop at Old Oak common.

The vertical alignment was based on minimising the gradients as far as is possible, whilst keeping this in balance with the resulting quantity of tunnels and viaducts required. The vertical profile assumed constant gradients between fixed points such as station box locations and minimum clearances to roads and railways; it did not account for sub-surface obstacles and an assessment is ongoing of impacts these may have on the profile.

The design of the tunnelled alignments would need to give consideration to the construction techniques. The vertical profile of the tunnels may be refined to provide more homogenous geotechnical parameters for the Tunnel boring machine (Tbm) to operate within. maintaining a set depth may result in excessive variety in the substrates tunnelled through, with a significant impact on Tbm design, construction rates and associated project risk.

The alignment5.3.2.

It would be necessary to run the route in tunnels from the Euston tunnel portal at Park Road as the available information on the existing rail corridor indicates that this has insufficient spare capacity to accept the additional dedicated HS lines which would be required.

The tunnelled route would swing round to head in a west-southwest direction in a curve with a horizontal radius of 1,600m and would pass to the north of Primrose Hill. This curve would limit the maximum speed to 180kph. As this is within 3.5km of Euston, this speed limitation would not significantly affect the journey time. Approximately 3km from the buffer stops at Euston, the tunnelled route would run along the same corridor as the tunnels carrying the WcmL and the London Overground services. The new HS tunnels would run beneath the existing tunnels, and the vertical alignment through this section would be set by achieving sufficient clearance beneath these existing tunnels.

The vertical alignment would also be dictated by the presence of any other significant deep services or installations. As the tunnels were sized for a maximum running speed of 225kph, this would allow tighter vertical curves than those used in the alignment design for the surface alignments across country. This would be of benefit should the vertical profile need to vary significantly to pass above or beneath existing obstacles.

Once the existing WcmL surface lines emerge from tunnel at South Hampstead Station, the HS alignment would continue parallel to this alignment heading southwest, but in an optimised form, with a constant gradient and straight horizontal alignment, subject to the route being free from sub-surface obstructions. From the LUL Queens Park Station, the straight HS alignment would result in the existing surface lines and the new tunnels diverging, and the tunnels passing beneath Kensal Green cemetery.

Through the route section, the HS alignment would broadly follow the existing rail corridor, but generally would not run directly under the existing rail infrastructure. The proximity to the rail corridor would appear to be the optimal route when consideration is given to the tunnel portal location and when trying to maximise the speed at which the new rolling stock could operate. conversely, the new tunnels would not run directly beneath the rail corridor, as the existing

57

LONDON

WESTMINSTER

ACTON

PUTNEY

HENDON

FULHAMBARNES

LAMBETH

HORNSEY

EDGWARE

CLAPHAM

CHELSEA

BRIXTON

FINSBURY

FINCHLEY

CHISWICK

WILLESDEN ISLINGTON

HAMPSTEAD

BATTERSEA

WOOD GREEN

WANDSWORTH

PADDINGTON MARYLEBONE

KENSINGTON

KENSAL TOWN

HAMMERSMITH

CAMDEN TOWN

FRIERN BARNET

Proposed Route

Tunnel

Viaduct


0 10.5Km

EuSton to olD oak Common - LINE OF ROUTE


infrastructure would be particularly sensitive to slight levels of ground movement arising from the tunnelling.

beneath Kensal Green cemetery, the alignment would swing around to a more westerly direction, and would pass beneath the Grand Union canal and into the station box for the station at Old Oak common. The ground level at the Grand Union canal is approximately 28m, resulting in sufficient clearance to the tunnels. In this area there are also two existing crossings of the canal; the A219 Scrubs Lane and a rail bridge carrying the West London Line. The tunnelled alignment would need to avoid passing beneath the abutments of these structures as they are likely to comprise deep foundations.

between the canal and the station box for the station at Old Oak common, the tunnels would pass beneath the tracks for the existing crossrail and GWmL Depots.

The track level in the Old Oak common station would be 9.5m, 15m below the ground level of 25.5m

Intervention Shafts5.3.3.

It was assumed that there would be three intermediate intervention shafts. The Euston tunnel portal would be at approximately chainage 1,300 and the Old Oak common station box at chainage 8,400.

Approx chainage of shaft (m)

current land use

3,200Residential and hotel car parking

5,100 Sorting office

6,700Residential properties, church and storage yard

Construction5.3.4.

It is presently envisaged that the tunnels would be constructed from Old Oak common towards Euston, such that (given the possibility of finding a large enough area for a work site including

segment storage) the muck-away would be brought to the Old Oak common end. This tunnelling would not be able to begin until the station box was substantially complete, and before station fit-out. It is envisaged that two Tbms would be used, with a slight lag between the two drives, and cutterhead refurbishment being carried out at the intermediate shafts. These tunnels would be through soft ground.

59


olD oak Common StatIon 5.4.

(wESt lonDon IntErCHanGE)

There would be a station at Old Oak common, constructed in an open cut box. It would occupy the site of the existing First Great Western Depot (which should become redundant in about 2020 after the introduction of IEP services) and Heathrow Express Depot (which would require displacement).

Platform arrangements -HS25.4.1.

There would be 6 platform faces: 3 Up faces served off the approaching Up line, and 3 Down faces similarly served off the approaching Down line; there would be no through lines, as HS2 Ltd advised that all HS2 trains would stop. The station would be served by two tracks both to the north-west and south-east, and, because all trains would stop, there would be no need to provide lengthy parallel lines such that non-stopping trains could overtake.

The station would be sub-surface since it would be served by tunnelled approaches from both east and west.

The overall length of the station and throat was minimised by tapering the island platforms at both ends.

The HS2 station could possibly provide for international services subject to their frequency, platform requirements and physical connections. This international connection could require a revision of track arrangements, possibly by placing the international line(s) as a centrally-located turnback facility, or as a dedicated platform with customs and security facilities. This international facility was not included at this stage of option development.

Platform arrangements 5.4.2.

– GWML and CrossRail

This station would provide interchange with the Great Western main Line. Two island platforms would be provided on the Fast Lines, to permit successive trains to call without cumulative delay. Each of the Relief Lines would have a single platform face, together with two platform faces to provide turnback facilities for crossrail.

Concourse5.4.3.

This station would essentially be an interchange with minor external passenger access. concourse facilities would be provided immediately above HS2 at approximately 6m below ground. This would link directly beneath the GWmL and crossrail at the same level. both GWmL and crossrail platforms would be served by two banks of two escalators per platform, together with lifts and stairs. Additional segregated space for international traffic could be provided.

Crossrail Depot5.4.4.

crossrail propose to site their new maintenance facility and stabling (up to 35 tracks) immediately north of the proposed HS2 Old Oak common Station. The new HS2 station would replace the existing GWmL depot.

The proposed crossrail depot does not have full grade-separation with the Relief Lines, but this would need to be reviewed if crossrail were to be extended to Reading (14tph) and there were to be a turnback at Old Oak common.

If the turnback facility were to be provided at Old Oak common, the Relief Lines to Old Oak common reach full capacity (24tph) and a grade-separated depot access could be required. This would be achieved by modifying the flyover east of Old Oak common, vacated since HS2 would displace the GWmL depot facilities.

This flyover returns to grade beneath the elevated West London Line to form the depot reception lanes.

Effects on Existing Old Oak Depot5.4.5.

The new HS2 station would replace the existing GWmL depot which would have, by this time, become largely redundant. The introduction of the new Inter-city Express Programme (IEP) services and accompanying relocation of facilities to the North Pole Depot leaves only Heathrow Express services using the old depot. This facility would require relocation probably to Heathrow.

61

Old Oak Common

Proposed Route

Tunnel

Viaduct


0 0.10.05Km

olD oak Common - STATION FOOTPRINT


Construction5.4.6.

The station would be formed in an open cut box (similar to that at Stratford International Station) approximately 850m long, 60m wide and 15m deep. The concourse would be sited at -1 level above the tracks (at level -2) with links direction to the at-grade new GWmL Station and crossrail Station beneath the existing GWmL tracks (at level 0). If emergency or full operational crossovers were required at both ends of the station, the box might need to be enlarged, and this was addressed as a risk issue.

The box would be sited to avoid conflict with the crossrail Depot access line.

The HS1 Connection5.4.7.

Old Oak common is a potential location for a connection to HS1 - this is described in a separate chapter.

OLD OAK cOmmON STATION -SEcTION

STRATFORD bOX - LONDON

63

OLD OAK cOmmON - PLATFORm LEVEL PLAN


olD oak Common to aCton Portal5.5.

Layout5.5.1.

At the western end of the Old Oak common station box, the HS alignment would comprise twin bored tunnels. These tunnels would be required due to the extensive domestic and industrial development in this area resulting in no suitable surface corridors for the new HS infrastructure. The tunnels would swing round to head north-west from the station box, with a radius capable of providing a line speed of about 270kph. As there would be a need to minimise tunnelling costs, it was assumed that these tunnels would be constructed at the minimum physical dimensions of twin 7.25m diam. This would restrict speeds to 225kph, but as it was assumed that all HS2 trains would stop at Old Oak common, this speed limitation should not be a major issue in terms of journey times. Should the “all trains stop” assumption be revised, the design of the station and tunnels would need to be revised.

The tunnels would rise to a tunnel portal location immediately to west of Park Royal Road. This area is currently in use as an aggregate storage yard, and would provide sufficient space to allow the construction of the portal structure. This area could also be used as the driving location for the tunnel, but it is envisaged that the Old Oak common site would be preferable as the existing rail infrastructure could be utilised for removing excavated material and transporting in tunnel lining segments.

The track level at the tunnel portal would be approximately 16m below ground level,

Construction5.5.2.

It is envisaged that the tunnel towards Acton would, like the Euston to Old Oak common tunnel, be carried out from Old Oak common station box. These would be much shorter drives and there are therefore two options in terms of tunnelling strategy:

Re-use the two machines from Euston to •

Old Oak common drives, with consequential programme implications of successive use;

buy a third machine to construct the two •

drives. Once the first drive is completed take the machine out, take it back to OOc station box and do the second drive. This would have the added advantage of having some Tbm redundancy in the case of a major problem with the Euston-OOc drives as these are also envisaged to be in soft ground.

65

Harlesden

East Acton

Stonebridge

North Acton

Lower Place

Old Oak Common

Willesden Green

Shepherd's Bush

ACTONProposed Route

Tunnel

Viaduct


0 0.20.1Km

OLD OAK cOmmON TO AcTON PORTAL


aCton Portal to HanGEr lanE5.6.

Design basis for the Surface alignment 5.6.1.

approaching London

The proposed alignment was based on running the new High Speed (HS) rail corridor immediately to the north of the existing central Line. It was also assumed that the existing Network Rail route from Old Oak common to South Ruislip would be abandoned. The central Line tracks generally run in the southern side of the existing rail corridor.

The design was based on providing twin HS tracks. As the rail corridor historically accommodated four rail lines, there would, at some locations, be sufficient space to run both HS2 and LUL lines in the existing corridor. The width might be achieved by the extensive use of steeper cuttings, retaining walls and steeper embankments. Even where the route could not be accommodated in existing boundaries, these techniques would be used to minimise land acquisition. The feasibility of these engineering measures would depend on a wide range of local issues such as geotechnical parameters of the ground, and access for construction.

Due to the radii of curvature on the HS lines, it would not be possible to construct all of the new alignment within the existing corridor. This would necessitate land take to the north of the rail corridor, and this would affect both industrial and residential properties. In most areas the additional width required would be less than 10m. Work would also be required to locally lower the track bed to provide the structure gauge clearance to existing structures. This was not considered in detail, as most of the road and rail bridges which the new HS lines would pass under would be demolished and replaced. The optimal solution in each location may therefore be a combination of both lowering the track bed and increasing the level of the new structure through local road modifications. In locations where the HS tracks are lower than the adjacent central Line tracks, lengths of retaining wall would be required.

In order to mitigate the noise created by HS trains, HS2 Ltd agreed to limit the maximum line speed locally to 250kph. The outline track alignment was based on maintaining the maximum possible track speed, should the 250kph speed limit be modified in the future.

Passive Provision for future Widening5.6.2.

Section 4.2 of the project specification requires the consideration of passive provision for four tracks. The design of this surface rail alignment based on four tracks could potentially be significantly different to that developed to date. A significant design and costing exercise would need to be carried out to determine which of the following options would be preferable. It is assumed that the initial construction would be of twin HS tracks, with the additional pair of HS tracks being added at some future point when demand justifies their construction. The three main options were considered.

option 1 - widen the Existing Corridor

This would convert the historic 4-track corridor to a 6-track corridor, with increased spacing between the tracks due to the speed of the trains. This would necessitate significant land take of industrial and residential properties over a length of 13km between Old Oak common and West Ruislip. The future widening of this corridor was considered feasible from an engineering perspective, but mitigation works would be required to minimise the impact on the central and chiltern Lines. This solution would impact significantly on the domestic and industrial premises in the footprint of the widened corridor. Whilst it could be possible to widen the corridor to the south, this would require the central lines to be moved.

option 2 - remove the Central line tracks

This option would remove these tracks from the surface corridor and reinstate these in tunnels below the existing rail corridor. The surface corridor would then be available for use for the 4-track HS alignment. This would require all of the LUL stations to be rebuilt and extensive

67

Alperton

West Acton

Park Royal

Stonebridge

North Acton

Lower Place

EALING

Proposed Route

Tunnel

Viaduct


0 0.20.1Km

AcTON PORTAL TO HANGER LANE


tunnelling beneath the original two track HS alignment which carries a number of associated risks. The advantage of this option is that the tunnels required for the underground lines would be smaller than the tunnels required for the HS lines should these be buried. Greenford station, which is a terminus on the First Great Western Line would need to be extensively remodelled. To accommodate the HS lines in the southern side of the existing rail corridor would also require extensive widening of the corridor as described in Option 1. Access to the Northolt Depot would need to be maintained and the tunnelled LUL lines would need to be brought to the surface in this location. Where the existing chiltern Line tracks run from Northolt Junction to West Ruislip these would need to be slewed across to run where the LUL lines were previously running. West Ruislip station would need to be remodelled both to accept the twin HS lines and the 4 HS lines.

option 3 – Construct HS in new tunnels

This option would require tunnelling beneath existing operation rail assets including the HS lines. To minimise the risk of ground settlement and disruption to the rail tracks, the tunnels would be at depth and additional mitigation measures such as compensation grouting may be required. This would require a portal structure to the west of West Ruislip where the additional twin tracks would diverge from the original twin tracks and dip down to the start of the tunnel. Due to the restricted width of the existing rail corridor it is not considered feasible to construct the additional HS lines as a cut and cover tunnel – this would cause severe disruption to both the HS and LUL lines.

overall width

For the surface alignment through London a corridor width of 22m was used, measured from the nearest rail of the existing rail infrastructure that would be retained (either chiltern lines or central Lines depending on the position along the route). The 22m comprises:

5m from the existing rail to the edge of the •

ballast trace (assumed to be sufficient to provide clearance for the existing trains, a separation fence and a single track access road with drainage etc). This is subject to further detailed studies of access requirements and separation from LUL lines.

14m ballast trace as specified in the Project •

Specification. It was assumed that track centres would be 4.5m, but this might be unnecessarily wide given the restricted speed of 250kph in this corridor;

3m space from the other side of the ballast •

trace for drainage, power supply ancillaries, retaining walls, etc. This was discussed with HS2 and was felt to be a reasonable assumption at this stage. No consideration has been given to the means of connecting any rail access track with the local road network.

Description - Old Oak Common to Hanger 5.6.3.

Lane

Over the 1.3km to the west of the Old Oak Tunnel portal, the track level would rise to the existing track level. This would require a long and deep retained structure too minimise acquisition. The gradient of the track along this section may be increased to bring the alignment to the surface over a shorter distance thus reducing the length of retaining walls needed, however this would affect the vertical alignment design between the tunnel portal and Old Oak common station. In the immediate vicinity of the tunnel portal, it is likely that limited additional land would be required outside the existing rail corridor to allow the HS lines to achieve sufficient clear distance between them prior to the commencement of the tunnels.

The route would then follow the existing surface rail line from Old Oak common towards South Ruislip, alongside the LUL central line. A north-side widening in the Park Royal area was preferred because of property, railway, road and other constraints. The corridor is tightly confined, and construction working space would be at a premium. All existing overbridges would have

to be demolished and replaced at the higher headroom required by HS2. Land take would be minimised by the extensive use of retaining walls, but some acquisition of residential property (generally gardens) and industrial property would be inevitable. There would be adverse, but possibly only temporary, effects on roads such as Rockware Avenue close to the railway boundary.

The first significant structures which would be encountered to the west of the tunnel portal, are the road and rail bridges at Park Royal. Due to the usage of these bridges, and there being no alternative to divert the services onto during replacement, these bridges would require an off-line solution. New bridges would be constructed adjacent to the existing bridges, and when complete the rail and road services would be diverted onto these. The old bridges would then be demolished. It is in this area that there are plans to site a new station on the central Line to serve the Park Royal development. No details were received on this, but it was assumed that this would be on the southern side of the rail corridor and as such would not affect the HS alignment. This station location would also link with the Piccadilly Line, and is likely to be to the east of the road bridge connecting coronation Road with the A40 (Western Avenue). Early liaison with the promoters and developers of the new station may facilitate the planning and construction of both the station and the HS lines. It is likely that the central Lines would be temporarily slewed to the northern edge of the rail corridor to allow the construction of the station; an operation which would not be possible should the HS lines have already been constructed.

HanGEr lanE5.7.

One of the most difficult areas is the A40 Hanger Lane Gyratory system, where the A40 runs east-west in an underpass, with Hanger Lane LUL station in the complex.

The gyratory is a very heavily trafficked junction and includes two overbridges; one with five lanes and the other with eight lanes. In order to accommodate the required Gc gauge for HS2 trains, it would be necessary to create additional headroom and widen the existing rail corridor. Lowering the HS2 alignment below existing levels might be possible, but would be complicated by the proximity of LUL lines and the bridge abutments. Raising the bridges would be problematic but is preferred to affecting the LUL alignments or station. However, increasing the span of the bridges whilst maintaining the LUL and the traffic system on the gyratory would not be possible.

Two options were considered in outline to avoid the need to replace the highway bridges. The first was to relocate approximately 1km of the surface tracked central Line into a sub-surface alignment in a new cut and cover tunnel. This would free up the surface corridor for the HS lines, but would require Hanger Lane station to be rebuilt as a sub-surface station. It would also result in extensive disruption to the operation of the central Line during the construction period. The second was to elevate approximately 1.5km of the surface tracked central Line onto a viaduct over the gyratory. This would again free up the surface corridor for the HS lines, but would require a high level Hanger Lane LUL station. This option would also result in significant disruption to the operation of the central Line during construction.

It was therefore decided by HS2 Ltd to retain the LUL lines in their existing location and to construct the HS lines to the north of these. This would result in both of the existing road bridges needing to be replaced, but this would be complicated by a horizontal curve in the existing rail corridor at this location. The alignment of the

HS lines would therefore pass through the corner of an existing office block, a builders merchants and a number of units on a new industrial park.

The proposals envisage the enlargement of the gyratory system by the construction of new bridges “outside” the present structures. It would appear to be possible to construct a new east bridge (at the Gc gauge clearance above the HS2 alignment) clear of the existing easterly bridge, with extensive and restrictive traffic management measures. Traffic would then be switched to the new bridge, and the present structure demolished. A similar process would apply to the west bridge, but there is less room available in this area. This enlargement of the junction may afford opportunities to include improvements to facilities for pedestrians and other vulnerable road users.

The enlargement of the gyratory system would involve the acquisition of a substantial number of residential and industrial premises, principally in the north-east quadrant, on Abbey Parade, Twyford Abbey Road and Hanger Lane.

It is envisaged that the existing LUL station and lines would remain in their present positions during and after the completion of the HS2 works. It might be necessary to temporarily slew the LUL lines northwards onto the abandoned Network Rail formation, with new temporary platform arrangements, in order to afford more construction space on the south side of the LUL lines for the new bridge abutments.

71

Alperton

Proposed Route

Tunnel

Viaduct


Proposed Roundabout

0 0.20.1Km

HANGER LANE


HanGEr lanE to SoutH ruISlIP5.8.

North-west of Hanger Lane, the HS lines would pass over the River brent on a new 120m long viaduct. This would run immediately to the north of the existing rail viaducts, and would require new embankments at each end. Due to the continued bend in the existing rail corridor, the HS alignment in this location would be situated approximately 40m to the north of the existing rail corridor.

Where the new HS alignment would deviate from the existing rail corridor, it would pass along the side of an existing industrial estate.

In this area through Perivale, and to the south of Perivale Industrial Estate, the existing corridor is predominantly straight and raised on an embankment above the adjacent ground level. Over a 3km length, seven existing rail bridges over roads would need to be widened. In some instances it may be necessary to only provide additional bridges for one HS line, with one HS line utilising the existing available bridges. These would need to be assessed for the dynamic and static loads imposed. Aged bridges may require strengthening works, but these would need to be ascertained by a detailed inspection and structural assessment. Apart from a few locations where industrial premises or domestic properties are immediately adjacent to the rail corridor, the impact of widening the existing corridor to accept twin HS lines should be minimal. This would include the stretch along the south of Perivale Industrial Park and the brent Valley bird Sanctuary.

At Greenford, the available rail corridor is severely restricted on the northern side by a series of aggregate yards, industrial premises and scrap yards. The HS alignment would be required to pass through these, utilising the land between the rail corridor and the adjacent street ‘Station Approach’. To the west of this section, a new bridge would be required over the Grand Union canal prior to the rail alignment entering a shallow cutting. This would necessitate the replacement

of the A312 road bridge and the Eastcote Lane road bridge over the rail corridor.

73

HAYES

ACTON

PINNER

KENTONHARROW

EALING

WEMBLEY

RUISLIP

EDGWARE

STANMORE

SOUTHALL

NORTHOLT

HOUNSLOW

CHISWICK

NORTHWOOD

ISLEWORTH

GREENFORD

BRENTFORD

HILLINGDON

Proposed Route

Tunnel

Viaduct


0 10.5Km

HANGER LANE TO SOUTH RUISLIP


nortHolt lul StatIon5.9.

Immediately to the west of the A312 road bridge is the location of Northolt LUL station.

This is located on the southern side of the tracks and is likely to be maintained in this location with minimal works. This however, would depend on how Heathrow Airport is served, as, if a HS delta junction with a spur down to Heathrow were required from this alignment, it is in this vicinity that the HS spur lines would deviate from the main through alignment. This would necessitate a corridor width sufficient to accommodate the twin central Line tracks and the four HS tracks. As the HS tracks would require a grade separated junction, the existing corridor width would be insufficient. A number of options were explored for this location including extensive widening of the existing corridor or running the central Line in tunnels. The nearest properties on the northern side are approximately 35m from the rail corridor and these would certainly be affected by the widening as this section is in a cutting. burying the central Line would require Northolt Station to be rebuilt with sub-surface platforms.

75

NORTHOLT

Proposed Route

Tunnel

Viaduct


0 0.080.04Km

NORTHOLT LUL STATION


SoutH ruISlIP5.10.

At South Ruislip, the chiltern line from marylebone and Neasden joins the proposed corridor at a grade-separated junction. The diverging line towards marylebone is a single-track link; the route from marylebone is also a single-track link, passing under the Old Oak line, merging into it south of South Ruislip Station. The LUL central line lies to the south of all the other lines. A waste transfer facility lies in the triangle of land between these lines.

The HS2 route would be on the northern side of the chiltern line, so would need to cross both the Up and Down line to marylebone, while at the same time attempting not to involve the demolition of the waste transfer facility.

A number of layout options were investigated in this area with the aim of allowing HS2 to pass over the two chiltern lines, all with the aim of meeting chiltern Railways’ aspirations for improved line speeds. This would allow HS2 to pass through South Ruislip at, broadly, existing levels, rather than having to be grade-separated over the Up marylebone. more layout development work is needed.

The waste transfer facility is served by a rail link used on a daily basis. This would be in the footprint of the HS lines, resulting in this facility being lost. In order to maintain the facility, it would be necessary to develop a layout incorporating the various requirements in the area.

South Ruislip Station would be remodelled, generally by a southerly slewing of lines and platforms to allow HS2 to pass to the north, in a complex staged implementation sequence. The HS lines would pass along the side of an industrial yard, impacting both the existing buildings and the access road to the yard. There appears to be little scope to widen the corridor at the southern side and slew all the lines across, so the impacts on the industrial area would need to be assessed in detail.

77

South Ruislip

Ruislip Manor

Proposed Route

Tunnel

Viaduct


0 0.40.2Km

SOUTH RUISLIP


SoutH ruISlIP to wESt ruISlIP5.11.

North of South Ruislip, there would be a 6-track rail corridor comprising twin LUL tracks, twin chiltern Line tracks, and twin HS tracks. The chiltern Lines would run in the centre of the available corridor. It is envisaged that these would need to be slewed over to the southern side of the available corridor, and hence run immediately to the north of the central Lines. This would maximise the space available for the HS2 tracks to occupy within the existing corridor, although online widening would still be required.The inclusion of HS2 into this corridor may introduce issues of signalling immunisation which will need to be addressed with LUL.

West of South Ruislip station and over bridgewater Road via a new bridge, the HS lines would run on an embankment along the side of a recreation ground to the north of Ruislip Gardens Station. The extent of the widening required along here would be approximately 15m. However, west of the new bridge which would be required over West End Road, there are properties immediately to the north of the embankment on which the railway runs. The properties back onto the railway with the rear walls of the houses being approximately 20m from the base of the embankment. It is likely that some land take would be required from the gardens, and the replacement of the existing tree covered embankment slopes with a vertical retaining wall.

Along this 1km length, the southern side of the rail corridor is formed by the LUL depot. It appears that the rail alignments could be modified to allow the central Line, chiltern Line and HS lines to be slewed to the south. This would potentially reduce the impact on the properties to the north of the rail corridor, but would introduce reverse curvature into the track alignments.

To the west of Ruislip manor, the rail corridor would continue along the edge of a recreational ground on a low level embankment and over the Piccadilly and metropolitan Lines to Uxbridge on a new bridge. At this location, 450m to the east

of West Ruislip Station, there are approximately 7 properties immediately adjacent to the existing rail corridor. Due to the widening, it was envisaged that retaining these would not be viable, however this would depend on the modifications made to West Ruislip Station, and the resulting impacts on the rail alignments. The widened corridor would then pass through a scrap yard and the car park of West Ruislip station.

To accommodate the HS lines through the station, it would be necessary to substantially remodel it, and to rebuild the bridge where the b466 (Ickenham Road) passes over the station platforms. The existing bridge would be demolished and replaced. This would have a high local impact, and the sequencing of these operations needs to be considered in detail to ensure that the station can continue to operate throughout the modifications. There would probably be a loss of platform capacity during the works.

79

Yeading

Ickenham

Eastcote

Hayes End

Hatch End

West Ruislip

Rayners Lane

Pinner Green

Colham Green

South Ruislip

Ruislip Manor

Wood End Green

Ruislip Common

Newyears Green

Ruislip Gardens

Pinnerwood ParkNorthwood Hills

North Hillingdon

Hillingdon Heath

Eastcote Village

HAYES

PINNER

RUISLIP

NORTHOLT

NORTHWOOD

HILLINGDON

Proposed Route

Tunnel

Viaduct


0 21Km

SOUTH RUISLIP TO WEST RUISLIP


wESt ruISlIP to amErSHam tunnEl 5.12.

Portal

From West Ruislip Station the route would continue to the immediate north of the chiltern line with the widening potentially affecting the Ruislip Golf club. Along this length it may be possible to widen the corridor to the south, and slew the chiltern Lines over. The basis for this is that previously it has been planned to extend the LUL central Line along this length to Denham, and the adjacent properties are therefore set back from the existing rail lines. Whilst minimising the impact to the north of the rail corridor, this would bring the alignment slightly closer to the houses on the southern side.

1km west of West Ruislip Station, the chiltern Lines turn slightly to the south. The HS lines would also turn to the south, but due to the radius of the horizontal alignment, the two rail corridors would start to diverge. The HS alignment would cross over the River Pinn on a new bridge and pass into a 1km long cutting. At this point the new cutting for the HS corridor would be adjacent to the cutting for the chiltern Line corridor. The most appropriate solution would need to be developed here, as it may be more practical to maintain a level ground profile between the two corridors.

The cutting would extend to a maximum depth of 20m. Whilst substantial, this would be as the adjacent chiltern Line cutting. If the HS track alignment were higher, this would reduce the depth of the cutting, but would have impacts on the adjacent alignments including through West Ruislip station. This may be able to be refined during the detailed design, but the overall principle of widening the existing corridor was to try to utilise similar track levels to facilitate the design and construction of overbridges.

The HS alignment would cross the River colne and its valley on a viaduct. The 3.6km long viaduct would be relatively low due to the shallow nature of the valley and the design being based on maintaining a constant gradient between the levels at each end of the viaduct. Should this

impose any unacceptable impacts it would be possible to change this to increase the clearance from the valley bottom by having the alignment on the viaduct rise to a vertical crest curve.

The viaduct would cross three flooded gravel pits, the River colne, the Grand Union canal and two roads including the A412 North Orbital Road. The length of individual spans and the locations of the piers would need to be determined based on detailed site investigations of the flooded gravel pits. The alignment design assumed that it would be possible to locate piers in the flooded gravel pits, although this would require extensive working on water.

The viaduct would end immediately to the north of Northmoor Hill Wood with the alignment then continuing in a series of embankments and cutting towards the m25. The topography of the land in this location results in the m25 being at the top of a slope. The HS alignment would therefore continue at a very shallow gradient and enter a tunnel portal immediately to the east of the m25. The gradient of the hillside would necessitate a 350m long approach to the cutting which could either be formed as a cutting or a retained structure. From tunnel portal the tunnel(s) would start and pass beneath the m25. The clearance from the track level to the road is 20m, and the potential for settlement of the m25 would be carefully assessed and monitored with suitable mitigation plans in place to avoid any operational disruption.

81

RUISLIP

UXBRIDGE

NORTHWOOD

HILLINGDON

RICKMANSWORTH

Proposed Route

Tunnel

Viaduct


0 2.51.25Km

WEST RUISLIP TO m25 PORTAL


amErSHam tunnEl - m25 to wESt of 5.13.

amErSHam

Layout5.13.1.

The route would be in tunnel from the m25 until a point to the west of Amersham Old Town. The route would consist of twin 8.5m internal diameter tunnels, connected by cross-passages at 250m intervals, allowing speeds of 320kph. The length of the tunnels would be approximately 9.6km.

Predominantly at a depth of at least 30m from track level to the ground, the tunnel(s) would run under fields to the north of chalfont St Peter and then pass under chalfont St. Giles. The route would then follow the River misbourne valley towards Amersham and pass beneath residential properties at the southern side of Amersham. The alignment would run to the north of Amersham Old Town before emerging at the tunnel portal.

Through this length the alignment was primarily dictated by the surface alignments to its east and west. These have more constraints on their line and level, and the tunnelled sections at either end are a continuation of the alignments and gradients used to develop the optimal surface alignment. Once in tunnel and at sufficient depth, there are few constraints on the horizontal and vertical alignment. The alignment developed utilises large radius curves to provide the shortest route between the tunnel portals. This could be developed during the detailed design to provide a refined solution suitable for the chosen construction methodology.

At the two locations where the alignment would cross the River misbourne, the depth of the alignment would be at least 20m. Detailed investigations would be required into the nature of the geology in the valley bottom at these locations. The presence of buried river valleys and saturated gravels or fines may require the tunnel(s) to be constructed deeper or special mitigation measures implemented.

It was assumed that emergency access and egress shafts would be required along the

tunnelled section at intervals of approximately 2km. The shafts would be generally located in areas adjacent to existing roads to facilitate both construction and long-term access. In some locations, local road construction would be required to provide suitable access.

The location and design of the shafts requires further refinement. The size of the shafts would depend on the use which is made of each, as, if these are also used for tunnel ventilation purposes, a larger excavation would be required. The spacing would need to be agreed with the relevant emergency services as part of the tunnel design works.

An area would be required around each shaft to allow construction. During long term operation, space would also be required around the shaft to accommodate maintenance vehicles and emergency services vehicles. These could be required to access the tunnels for both routine and emergency maintenance access, during training exercises and in case of tunnel evacuation.

Construction5.13.2.

This would be a long tunnel under residential areas, and would probably use Tbm construction techniques. The two ends of the tunnel would be in relatively empty areas in terms of construction site, but proximity to the motorway could be advantageous. The proximity of the south end of the tunnel to the chiltern line may allow the use of rail transport for spoil disposal.

At least two Tbms would be used. These two tunnels would, on present information, be constructed in chalk. A possibility would be to drive from each end of the tunnels if the tunnel was on the critical path - i.e. have four Tbms, which could be removed from an intermediate shaft.

83

AMERSHAM

CHORLEYWOOD

GERRARDS CROSS

Proposed Route

Tunnel

Viaduct


0 2.51.25Km

TUNNEL - m25 TO AmERSHAm


amErSHam to lIttlE mISSEnDEn5.14.

The alignment to the west of the Amersham would initially comprise approximately 2.25km of deep cutting. This would run parallel and to the north of the A413 bow Road dual carriageway through the Shardeloes garden. The alignment in this section would be between 10m and 20m below the existing ground levels, the principal reason being that, at each end of this surface alignment, there are lengths of tunnel. At each tunnel portal, the alignment would need to be sufficiently below the ground levels. If the ground were level, it would be preferable to bring the alignment closer to the surface where it is not in tunnel. However, in this location the ground level is rising steeply from east to west, and this complicated the alignment design. Further complications in the vertical alignment were caused by the consecutive horizontal curves required to maintain the HS corridor between the existing rail and roads.

This section of the alignment comprises a series of transverse valleys running down to the main valley. The HS alignment would cross these, resulting in significant variations in the depths of cuttings. Due to the sensitive nature of this location it may be preferable to construct the cuttings as a retained, or partially retained, solution. This would reduce the width of the HS corridor. It may also be preferable to construct this section as a series of cut and cover tunnels but this is subject to further review and would need detailed consideration. moving the horizontal alignment slightly towards the A413 may result in lower ground levels with an associated reduction in the depth of cutting required. This would have a consequential impact in that it would bring the alignment nearer to residential properties in Amersham and along the valley.

To cross beneath the existing railway it would be proposed that a jacked box be used. There is a minimal quantity of cover in this location so additional measures may be required to control settlement of the existing rail lines. This may include proactive ground strengthening and

reactive compensation grouting. Utilising a jacked box, with progressive excavation at the face, would provide continual support to the overlying ground. Once the jacked box was in place, the remainder of the tunnel could be excavated from this. Alternatively the tunnel could be constructed from the western side of the hill and ending in a breakout.

85

Woodrow

NewtownHilltop

Waterside

Pond Park

Coleshill

Lower Bois

Hyde Heath

ChessmountSouth Heath

Penn Street

Penn Bottom

Beamond End

Chesham Bois

Mantles Green

Winchmore Hill

Pednormead End

Little Missnden

Little Wood Corner

Amersham on the Hill

Ballinger Bottom (South)

CHESHAM

AMERSHAM

Proposed Route

Tunnel

Viaduct


0 10.5Km

AmERSHAm TO LITTLE mISSENDEN


lIttlE mISSEnDEn tunnEl5.15.

The route would pass beneath the existing rail corridor and into a 1.05km length of tunnel under a hill. because of its short length, the tunnel would be a single 9.8m internal diameter tunnel, allowing speeds up to 320kph.

The ground surface climbs to the north. The tunnel vertical alignment would also need to climb to match, as, if the bottom of the valley were followed instead, this would result in an excessively sinuous horizontal alignment. To achieve a high-speed alignment, it was necessary to have an alignment rising up to the northern side of the valley, and it would then run along the relatively level top of the chiltern Hills. This would also result in the alignment being further away from the centres of population in Little missenden and Great missenden.

The western side of the hill (which is tunnelled through) is very steep resulting in the approach portal being only 100m long.

87

Hyde Heath

Little Missnden

Proposed Route

Tunnel

Viaduct


0 0.30.15Km

LITTLE mISSENDEN TUNNEL


lIttlE mISSEnDEn to wEnDovEr5.16.

The route would continue to run at approximately ground level and follow up the hillside for the next 2km to South Heath. This length would predominantly be in cutting, but these would typically be less than 10m deep. The alignment would pass through one hamlet, and would require a number of roads to be modified.

To the west of South Heath, the route would be level through the surrounding gently undulating topography. by designing the corridor to be predominantly in a shallow cutting with a maximum depth of 10m, this would provide a level of noise and visual impact mitigation. Road crossings would be elevated over the route. The route would pass through a set of HV electricity cables supported by pylons. These may need to be relocated, but the impacts of this on the electricity distribution network were not investigated. Should it not be feasible to move these, the route may need to be revised. For the majority of this length, the route would run parallel to the pylon line.

Another feature which it was not possible to avoid is Grim’s Ditch. The HS alignment would cross this historical feature to the east of cottage Farm. Adjusting the alignment to the east to avoid this feature would result in the alignment passing through an increased number of properties. The relative importance of this feature would need to be investigated in detail and the potential impacts on the alignment incorporated in the further design phases.

At the western end of the level alignment along the top of the chiltern Hills, the route would follow the hillside down towards Wendover. The vertical curve would start at approximately the crossing of bowood Lane. The alignment would be generally maintained above the existing ground levels on a series of embankments. A 450m viaduct would be required to cross the steep valley (Wendover Dean) in the vicinity of Durham Farm. The use of an elevated alignment would necessitate a series of underbridges for the roads which would be crossed between the top of the hill and the A413 London Road.

A further 600m viaduct would be used to cross the A413, railway and adjacent road. This crossing would be complicated as the

alignment would be highly slewed. A clearance of approximately 10m is currently present between the existing road level and the new rail level. This would be reduced by the structure of the viaduct, and should this be insufficient the roads may need to be locally diverted and lowered. It may be feasible to elevate the route further north where it drops down from the top of the chiltern Hills. by doing this the height of the embankment would be increased, and this would need to be considered as part of the environmental impact appraisal as it could potentially increase the noise and visual impact.

West of the A413 transport corridor, the route would continue to run adjacent to the A413 Nash Lea Road, which would result in impact on residential properties. The alignment would pass through the confined space between the A413 and property on bacombe Lane. However it would result in the acquisition of residential property on Ellesborough Road as the alignment can not avoid the houses there. Running immediately adjacent to the A413 would also require a significant length of electricity pylons to be relocated, and there are no obvious locations to relocate these to.

The crossing under Ellesborough Road would require the road to be elevated. It is currently proposed that this length of the HS corridor be in a cut and cover tunnel to minimise the noise impacts on the adjacent properties. As the cover is very shallow in this location this would need to be reviewed once the vertical alignment has been finalised.

The route would then continue to run to the south-west of the Wendover bypass, generally on embankment up to 5m high, and would pass near the junction of Nash Lea Road (b4009) and Nash Lea Lane.

89

WENDOVER

Proposed Route

Tunnel

Viaduct


0 10.5Km

LITTLE mISSENDEN TO WENDOVER


wEnDovEr to StokE manDEvIllE/5.17.

aylESBury

The route would run north-westwards to pass to the west of both Stoke mandeville and Aylesbury.

It would cross above the A4010 Risborough Road at a gap in property near Old Risborough Road, and this section would run on a viaduct avoiding the flood plain. The route would pass under marsh Lane, and inevitably close to residential property to the south-west of Stoke mandeville arising from the restricted space available. At Stoke mandeville, the route would follow a tributary of the River Thames; this would prevent disruption to the town by partially running along the tributary’s undeveloped flood plain.

The route would be elevated via a lengthy viaduct, passing property at the edge of the Southcourt area of Aylesbury and avoiding a series of flood plains.

The route would cross the existing railway from Princes Risborough to Aylesbury, but this might have to be re-aligned to create sufficient vertical clearance. The vertical alignment in this area is affected by a number of factors, and more investigation is needed.

The route would pass in close proximity to the western outskirts of Aylesbury, particularly in Hartwell area; this was deemed necessary in order to avoid the village of Stone, just to the west of Aylesbury.

The line would be elevated to pass over another flood plain and the A418 Oxford Road, affecting the lower Hartwell area and the Aylesbury Park Golf club. It was not possible to avoid this due to the geometry of the vertical alignment. Adjusting or lowering the alignment would result in a deep cutting or a lengthy tunnel. The relative importance of this feature would need to be investigated in detail and the potential impacts on the alignment incorporated in the detailed design phase.

91

WENDOVER

AYLESBURY

PRINCES RISBOROUGH

Proposed Route

Tunnel

Viaduct


0 10.5Km

WENDOVER TO STOKE mANDEVILLE/AYLESbURY


aylESBury to quaInton5.18.

North of Aylesbury and Stone, the route would generally follow the existing terrain, subsequently being raised on a viaduct to cross the River Thame and its flood plain.

The alignment would then pass over A41, and would run further to the north-west to minimise disturbance to Waddesdon in the south. The line would generally be at-grade except for a short section on viaduct/bridges over the River Ray and its flood plain.

North of Quainton, the topography becomes relatively flat and the line would be at-grade in general. It would pass close to Sheephouse Wood (an SSSI), and would follow the existing freight line from Aylesbury to claydon. Retaining structures would be provided in order to minimise the impact to the nature zone.

93

AYLESBURY

Proposed Route

Tunnel

Viaduct


0 10.5Km

AYLESbURY TO QUAINTON


quaInton to BraCklEy5.19.

From Quainton to brackley, the alignment would follow an existing freight line and would then make use of a dismantled railway corridor. This would attempt to minimise the effects on Twyford, Godington, chetwode, barton Hartshorn and mixbury.

The topography between Quainton and Godington is fairly flat, but the line would be kept above the ground level using viaducts as there are a series of flood plains that would need to be crossed.

In the calvert area, an HS2 infrastructure maintenance depot is proposed. The depot would be alongside the existing East - West Rail route between bicester and bletchley, near Steeple claydon. Placing the depot here would allow maintenance trains and on-track plant (for example ballast trains) use the WcmL at bletchley to gain access to HS2. There would be a link connecting HS2 to East – West Rail, which itself would need to be grade-separated over HS2, potentially involving re-alignment and raising over a distance of up to 3km. The critical distance associated with the design on HS2 is the loop lines adjacent to the main line. There would need to be provision for locomotives to run round their engineering trains. Turnouts to and from HS2 and East – West rail would be needed, and 80kph switches were assumed. The link to and from East – West rail would need to be capable of bi-directional operation. The depot itself was modelled on the Singlewell Depot on HS1. The depot would consist of:

Office accommodation, workshops •

and internal storage;

maintenance shed;•

Rail plant fuelling points;•

Area for materials and equipment;•

Access roads and parking;•

Security measures. •

Further investigation is needed to devise an optimum layout accommodating the existing lines, the HS2 line, and the spur to the maintenance depot.

North of calvert, the topography starts to change; the land starts to rise and become hilly, such that the alignment would need to enter a series of cuttings. The line between Godington and brackley would cross a number of waterways, but the topography of the area lends itself to creating a vertical alignment crossing these obstructions using viaducts. The horizontal alignment would start to divert north-west from mixbury towards brackley.

The alignment would pass east of brackley, crossing the A43 at an oblique angle; it is anticipated that the line would pass over this area on viaduct. The topography of the area lends itself to the construction of a viaduct, in order to minimise flooding from the Great Ouse river. The alignment in this area was placed to minimise the effects on brackley, and would avoid the settlements of Turweston, the SSSI at Radstone and the airstrip at the east of Turweston.

95

BRACKLEY

BICESTER

BUCKINGHAM

Proposed Route

Tunnel

Viaduct


0 21Km

QUAINTON TO bRAcKLEY


BraCklEy to ufton / lonG ItCHInGton 5.20.

wooD

The alignment would follow existing ground levels from brackley, but would then encounter hilly terrain through Greatworth and Thorpe mandeville, with a series of deep cuttings and high embankments, as it could not follow the rolling topography. The route would avoid clashes with a number of Ancient monuments, but would pass through the disused World War II airfield of RAF chipping Warden. The alignment would cross the Oxford canal shortly after Wormleighton, then would need to cross a series of waterways and flood plains on viaducts and bridges towards Ladbroke before passing south-west of Southam.

97

BANBURY

DAVENTRY

BRACKLEY

Proposed Route

Tunnel

Viaduct


0 2.51.25Km

bRAcKLEY TO UFTON / LONG ITcHINGTON WOOD


lonG ItCHInGton wooD tunnEl5.21.

At Ufton, the alignment would affect Ufton Wood and Long Itchington Wood (an SSSI). It is therefore proposed to place the route in a tunnel of 1400m in length, from Ufton Hill Farm to Wood Farm. The tunnel would be a single-bore two-track tunnel of 12.8m internal diameter, designed for a maximum line speed of 400kph. The alignment would enter a deepening cutting before entering the tunnel portal north-east of Ufton as well as underneath the A425, after passing through areas of flood plain on a series of short viaducts /bridges.

99

Ufton

Bascote Heath

Proposed Route

Tunnel

Viaduct


0 0.20.1Km

LONG ITcHINGTON WOOD TUNNEL


ufton / lonG ItCHInGton wooD to 5.22.

Burton GrEEn

Upon exiting the tunnel at Wood Farm, the alignment would pass over the Grand Union canal and enter a cutting to the east of Offchurch. The line would not follow the existing surface topography but would be on high embankment with a short viaduct over the River Leam. The route would pass east of cubbington, avoid tunnelling, but passing through South cubbington Wood.

The route would then pass between the grounds of the National Agricultural centre (NAc) and Stoneleigh village, resulting in it passing through Stoneleigh National Park and Garden. The route would be at ground level, but would pass over the River Sowe and one of its tributaries. It might be possible to re-align the route through the grounds of the NAc, severing it, or requiring a cut-and-cover tunnel to avoid permanent severance.

The route would pass over the A46 near the Stoneleigh junction. The alignment would not have enough clearance to pass below the A46 as the alignment would be either on viaducts or above ground prior to this section, due to the geographical location of a series of flood plain between cubbington and Stoneleigh. Alternatively, it would include a long and deep tunnel option that would be very costly.

The route would then cross over Finham brook, the Leamington – Kenilworth – coventry railway line, and the A429.

In order to run north of crackley, the route would not follow the dismantled rail corridor on

the eastern boundary of Kenilworth, but would cut through the birches Wood Farm area and broadwells Wood. It would then join the alignment of Route 3, passing through a constricted gap in property at burton Green, joining the existing dismantled railway corridor there.

101

COVENTRY

WARWICK

BEDWORTH

KENILWORTH

STRATFORD-UPON-AVON

ROYAL LEAMINGTON SPA

Proposed Route

Tunnel

Viaduct


0 31.5Km

UFTON / LONG ITcHINGTON WOOD TO bURTON GREEN


Burton GrEEn to tHE nEC arEa5.23.

On the approach to the m42 transport corridor, the proposed alignment was placed to avoid multiple crossings of the meandering River blythe (SSSI) and avoid disruption to berkswell Station which serves the existing birmingham to coventry Railway. In order to achieve speeds of 400kph and accommodate a desirable birmingham Interchange Station, there was little flexibility in terms of alignment through this area.

East of berkswell Station, the alignment would diverge away from the existing disused railway corridor and would cross the birmingham to coventry Railway Line north of balsall common and berkswell Station on a 50m bridge, 8m high. The alignment would miss the lakes adjacent to the station and would then roughly follow the A452 as far as middle bickenhill. A major permanent diversion of the A452 would be required east of Hampton in Arden to lift the road over the route, as this would be less costly and intrusive than lifting the HS2 route over the road.

The existing A45 would need to be raised by about 3m, with a new overbridge to enable HS2 to approach birmingham Interchange Station at-grade. Elevating the railway over the A45 would result in the entire station being elevated with substantial embankment works and elevated throats at both station ends. This would be considerably more costly than the current proposed option.

103

Knowle

Meriden

Hockley

Fen End

Barston

Balsall

Pickford

Outwoods

Meer End

Maxstoke

Hook End

Eastcote

Sedgemere

Kinwalsey

Green End

Four Oaks

Berkswell

Beechwood

Walsal End

Rotten Row

Stonebridge

Lodge Green

Eaves Green

Carol Green Reeves Green

Oldwich LaneDarley Green

Chapel Green

Chadwick End

Burton Green

Benton Green

Wootton Green

Newhall Green

Flint's Green

Temple Balsall

Pickford Green

Hollyberry End

Chessetts Wood

Balsall Street

Balsall Common

Catchems Corner

Hampton in Arden

Bradnock's Marsh

Middle Bickenhill

Little Packington

Upper Eastern Green

Proposed Route

Tunnel

Viaduct


New Highway Works

People Mover

Station

0 0.750.375Km

bURTON GREEN TO THE NEc AREA


BIrmInGHam IntErCHanGE StatIon 5.24.

An interchange station would be provided near to the existing birmingham International Station serving both the Airport and NEc.

Track arrangements5.24.1.

South of the station, HS2 would bifurcate via 230kph turnouts to form a 4-track railway, and the outer pair of lines would then further split via 95kph turnouts to create 4 platform lines (an Up Island and a Down Island); there would be 2 through lines. North of the station, there would, like in the south, be a 4-track railway, with the outer pair of lines further bifurcating (230kph Turnouts) to create a 2-track route towards central birmingham and 2-track passive provision (somewhat further north) towards the m42 corridor, the East midlands, South Yorkshire, West Yorkshire and North-East England.

105

Bickenhill

Stonebridge

Chelmsley Wood

Middle Bickenhill

Little Packington

Proposed Route

Tunnel

Viaduct


New Highway Works

People Mover

Station

River Diversion

0 0.40.2Km

bIRmINGHAm INTERcHANGE STATION


bIRmINGHAm INTERcHANGE STATION - LOcATION PLAN

107

The Interchange Concept - Station 5.24.2.

arrangement

The station would be modelled on the similar station at Ebbsfleet on HS1. Situated east of the m42, near to NEc, birmingham International Station and birmingham Airport, it would be a parkway-style station, with major road access requirements and car parking provision. There would be inter-connected access between all these components.

Two island platforms (four platform edges) would be provided, as well as two through non-stop lines. The westerly island would serve trains towards central birmingham, or those stopping services on the London to North-West axis, as well as potential train services towards Yorkshire

and North-East England. The southbound platform would be fed by trains from birmingham or the North towards London. Each platform island would be accessed by two banks of two escalators. Escape bridges would also be provided to the extreme ends of the platforms.

The concourse, directly accessed from the multi-storey car park to the east, would be suspended above the platform level. The concourse would connect directly to a people-mover adjacent to the platform zone aligned approximately north-south. This would provide interchange with the NEc Halls, birmingham International Station, and birmingham International Airport.

bIRmINGHAm INTERcHANGE STATION - cONcOURSE PLATFORm LEVEL


Highway access arrangements5.24.3.

Local transport demand data was used, supplemented by HS2’s demand model to derive an indicative estimate of the numbers of passengers (approximately 20,000 passengers per day to and from London) forecast to use the proposed station (although the number of trains and journey times was not known with accuracy). These daily demand figures were converted into hourly forecasts, and an assumption of car occupancy was used to derive vehicular flows. Further assumptions were then made on the origin of trips, and the routing of their arrival in the immediate local area. Using existing data on highway flows, and taking into consideration discussions with the Highways Agency, the process produced a forecast of potential additional flows on the highway network.

From this, indicative highway improvements were identified, principally being;

The size, scale and location of a connection •

from the station itself to the local network (assumed to be off the A452);

Improvements and widening of the •

circulatory carriageway and bridges at m42 J6 (NEc Junction);

modification of A45 between m42 J6 and •

the A45/A452 junction (Stonebridge)

A segregated left-turning lane, with signalisation •

and circulatory carriageway widening on A452 between Stonebridge and the Station Junction.

Widening of the circulatory carriageway •

and full signalisation at m6 J4 (coleshill).

bIRmINGHAm INTERcHANGE STATION - cONNEcTION TO AIRPORT

109

Car Parking5.24.4.

The demand figures were used to derive an indicative number of car parking spaces required at the Interchange. consideration was given to a surface car park, but this proved to be of such a size that walking distances and times from the remote parts of the car park could easily negate much of the train services time savings, as well as creating complex drainage issues. It was therefore assumed that multi-storey provision adjacent to the proposed station building would be required. A total of 7,000 spaces was calculated, over 5 floors, in a building of approximate dimensions 200m x 200m.

Internal Circulatory Road System5.24.5.

Given the car park location, a tentative layout was prepared for an internal roadway system, serving the car park, a short-stay / drop-off area, and provision for coaches, taxis etc.

a People Mover to the airport5.24.6.

One of the advantages of the proposed station is the proximity to the NEc and birmingham Airport. A people-mover would be required to facilitate connectivity. This connection would need to be of high capacity (potentially significant numbers of users at major NEc exhibitions etc) and of high-speed as the distances involved

are lengthy. It was assumed that a maximum of 2,000 passengers per hour would be carried, in vehicular units of about 100 passengers at a frequency of 20 per hour.

Several types of people mover system were considered, including monorail, bus, light rail or automated guided transit systems. A twin track APm system was assumed. An indicative alignment was then derived using relevant technical parameters. most of this alignment would be on high-level structure crossing the m42 and would connect into the NEc and Airport. The costs assumed a monorail system, with the other types of systems included in the risk / opportunity allowance.

River Diversion5.24.7.

The proposed station would cross Hollywell brook, and a high-level study was undertaken to look at the extent and effects of any river diversion. It was established that an approximate 1,200m diversion would be required with a 50m bridge, 3m high, built to carry the High Speed lines over the diversion adjacent to the A45. This diversion was not considered likely to adversely affect the hydrology in this area. The south end of the station would be built on fill.

bIRmINGHAm INTERcHANGE STATION - SEcTION


DElta junCtIon5.25.

Overall Layout5.25.1.

A triangular “Delta Junction” would be created west of coleshill. The three sides of the triangle would be;

A main HS2 line running approximately north-•

south (the east link), named the ‘mainline’.

A twin-track link towards birmingham •

heading north-west, then west towards the Water Orton area (the south link), named the ‘Up and Down birmingham’.

A twin-track link from the Water Orton •

area back to the HS2 main line (the north link), named the ‘Up and Down Spur’

The overall form of the junction was aimed at achieving high north-south “through” speeds on the London to West coast main Line axis, with lesser speeds to and from birmingham, on both the north and south links, and was also aimed at avoiding effects on coleshill Pool SSSI. The speed on each of these links was optimised but it is recognised that further layout work will be required once more is known about capacity requirements, stopping patterns at the proposed Interchange Station, and the train service frequencies on the north and south links.

The north and south links would form grade-separated junctions with the east link. These grade-separated junctions would require long viaducts due to the skew of the crossing angles and presence of flood plains. It is also proposed that the west junction (where the north and south links meet) would also be a grade-separated junction, with the Up and Down birmingham being the turnout route.

The Delta junction arrangement would intercept a number of significant features including motorways, existing railways and rivers for which underbridges would be required. The frequency of these features means that much of the Delta would be situated on high embankments or elevated structures up to 2km in length. A number of local roads would also need to

bridged, and possibly diverted, to accommodate the junction. costings considered the additional costs associated with short-term possessions of both existing railways and highways.

The Delta Junction was primarily located to provide a connection to and from central birmingham, and was fortuitously situated to facilitate a potential link from both HS2 (from London) and from birmingham to the East midlands, South Yorkshire, West Yorkshire and North-East England by creating a stub connection aligned towards the m42 corridor. Initial alignment work was undertaken on the potential link to the North-East to ensure that the corridor towards Kingsbury and the m42 was credible.

Some preliminary visualisations of the Delta Junction, overlain on Google Earth imagery, are presented. more work on the Delta junction is needed to provide a more consistent pattern of achievable speeds, and to relate the speeds on the North link and South link in relation to emerging train service patterns.

East Link (Mainline)5.25.2.

North of the proposed birmingham Interchange Station, the east link would cross over to the west side of the m42 and then over the m6 and immediately west of the motorway link road which executes a 270° loop to carry northbound m42 traffic to the eastbound m6. The primary purpose of this alignment was to avoid any impact on coleshill and bannerly Pools SSSI and to create a long section of straight track to accommodate all the necessary switches and crossings between different lines. The vertical alignment of HS2 would involve the total demolition of the existing roundabout over the m42 which serves the A452, A446 and b4438 to enable the mainline to cross over the m42 at approximately 8m above the motorway. This roundabout would be rebuilt north of the proposed Interchange Station with a link road crossing the mainline and m42 to serve the b4438. Additionally coleshill Heath Road would need to be raised over HS2. It is thought that the existing bridge carrying coleshill Heath

111

Gilson

Cole End

Curdworth

Coleshill

Kingshurst

Fordbridge

Water Orton

Lea Marston

Bacon's End

Chattle Hill

Proposed Route

Tunnel

Viaduct


0 0.50.25Km

DELTA JUNcTION


113DELTA JUNcTION NORTH cONNEcTION LOOKING NORTH


115DELTA JUNcTION NORTH cONNEcTION LOOKING EAST


117

DELTA JUNcTION WEST cONNEcTION


119

DELTA JUNcTION SOUTH cONNEcTION


121

DELTA JUNcTION - VISUALISATION


Road over the m6 and its slip roads would remain untouched.

beyond the ‘South link’, the main lines would cross back over to the east side of the m42 to avoid the elevated motorway slip roads serving the m42 and m6, as well as the village of Gilson. In order to avoid substantial land take requirement from Hams Hall Distribution Park and the Sewage Works, and facilitate a further long section of straight track to fit all the required switch and crossings, it would be necessary to pass close to the village of Gilson. New underbridges and the temporary diversion of the A446 would be required to carry the mainline over the A446 and adjacent existing birmingham to coleshill Railway line.

The permissible speed through the proposed Interchange Station up to the crossing with the m6 would be 400kph. Speeds would then be restricted by horizontal geometry to 315kph adjacent to the 270° loop and 320kph crossing back over the m42. Thereafter, speeds could increase to 400kph. Further detailed design should prove that faster speeds through this region are achievable, but the various physical and railway operational constraints mean that speeds are unlikely to be significantly greater than 320kph.

South Link5.25.3.

The South link was designed as the turnout route from both the mainline and Spur lines. The radii would allow speeds of 230kph throughout the link. As the eastern main line link would be on a 2km viaduct (height varies between 7m and 15m above existing ground) to carry the lines over the m6 and m42, it is proposed that the Up birmingham Line would pass under the mainlines before converging towards the Up birmingham Line.

On the approach to the motorway slip roads serving the m6 and m42, it is proposed that two bridges, each 100m long and 8m above the road, would carry one of the birmingham Lines over the slip roads before tying into the Spur lines. The design currently assumes that a 230m viaduct, 8m high, would carry the Up birmingham over

the Spur lines to tie into the Down Spur to form a grade-separated junction.

north Link5.25.4.

The north link would connect the High Speed lines that run alongside the existing Water Orton railway corridor to the mainline between the existing birmingham to Kingsbury and coleshill railway lines. Speeds would be restricted to 200kph west of Water Orton due to presence of the m6 and Water Orton Primary School. In order to tie into the mainline, speeds would be further restricted to 170kph due to a tight 1,300m radii.

A 200m viaduct, 8m high, would be required to carry the Down Spur over the m42 before tying into the mainline. A 1,390m viaduct of varying height would be required to carry the Up Spur over the m42, the mainline, flood plains and existing railways before tying in. The mainline was located as close as possible to Hams Hall Distribution Park to maximise the radii and speed joining the mainline.

DElta junCtIon to BElfry Golf CourSE 5.26.

The main HS2 route would continue on a straight alignment north of the Delta Junction to allow the opportunity to incorporate the switches and crossings needed for a possible HS route towards the m42 corridor.

It is proposed that the 4-track railway would converge back to a 2-track railway via 230kph turnouts south of the crossing with the m42. A 320m viaduct, 8m high, would then be required to enable the mainline to pass over the m42 and the birmingham and Fazeley canal. Line speed through this region would be up to 400kph.

The belfry Golf course was recognised as a physical constraint and the route was located to minimise effects and land take. Investigative work was carried out on whether realistic speeds could be maintained by passing between belfry Golf course and the village of middleton. Speeds greater than 300kph were not possible, so it was decided that the route would pass east of middleton.

123

Wishaw

Marston

Stoke End

Lea Marston

Hunts Green

Bodymoor Heath

Proposed Route

Tunnel

Viaduct


0 0.40.2Km

DELTA JUNcTION TO bELFRY GOLF cOURSE


Two structures of 120m and 265m, 3m and 5m high respectively, would be required to carry the route over the flood plains adjacent to belfry Golf course and a major permanent diversion of the A4091 would be required.

nortH of tHE BElfry 5.27.

East of middleton, speeds would be restricted to 350kph to enable the alignment to pass west of Hints and to avoid the area of higher ground and quarry north east of Hints. bourne brook passes to the south of Hints, and a 170m bridge, 13m high, would be required to carry the mainline over its flood plains. A 320m retaining wall would be required to prevent the railway embankment footprint infringing on the flood plain. North of middleton, the alignment was designed for 400kph for future high speed connectivity to the North East and West.

Near Weeford, the A5 would need to be raised to lift it over the route. It is proposed that a new bridge would be built off-line and the A5 permanently diverted once complete to avoid major disruptions to a relatively busy highway link.

The alignment would then aim for a relatively narrow gap north of Lichfield and south of Streethay. The approach to this gap was designed to avoid farm properties between Hints and Whittington Heath Golf course. A 1780m straight alignment was incorporated (adjacent to Whittington Heath Golf course) to facilitate possible connections to the North West and North East.

125

LICHFIELD

TAMWORTH

SUTTON COLDFIELD

Proposed Route

Tunnel

Viaduct


0 21Km

NORTH OF THE bELFRY


lICHfIElD5.28.

At Lichfield, consideration was given to the connection into the West coast main Line and also to a potential further northerly extension to HS2 itself. It is proposed that the High Speed lines would be elevated on a 685m long viaduct, between 8m and 14m high, to cross over the A38, existing railways and A5127.

An alignment north of Streethay was dismissed due to the additional speed restrictions and length of track, as well as the environmental impact on passing adjacent to a scheduled ancient monument.

The alignment would then run parallel to the West coast main Line until its tie-in point north-west of Lichfield. Through Lichfield, speeds would be restricted by horizontal geometry to 250kph. Any possible high-speed route to the North-West could possibly be achieved, and a 3,900m length of straight was incorporated into the design. It would also be possible to modify the approach geometry south east of Lichfield to incorporate higher speeds but this would undoubtedly lead to further land acquisition.

It would be possible to include a connection to the Lichfield to Wichnor junction line, affording the opportunity for HS2 trains (from either London or birmingham) to access Derby and South Yorkshire. Trying to accommodate all the HS2 northerly extensions, links to Derby, links to the WcmL in a 3-way junction would need to be the subject of further study.

127

LICHFIELD

Proposed Route

Tunnel

Viaduct


0 10.5Km

LIcHFIELD


ConnECtIon Into tHE wESt CoaSt 5.29.

maIn lInE

It is proposed that a grade-separated junction would be formed with the West coast main Line, in the Elmhurst area.

connections would be provided from Down HS2 to both Down Trent Valley Slow and Down Trent Valley Fast, and from both Up Trent Valley Slow and Up Trent Valley Fast to Up HS2. A pair of crossovers between the HS2 lines would be provided as close to the junction as possible.

This would ensure operational flexibility and compatibility with the bi-directional signalling on the Trent Valley lines. The HS2 / WcmL connection would be “straight”, with the turnouts and associated layout for the WcmL route designed to match the existing 200kph linespeed of this section.

creation of this junction would involve slewing of the existing tracks to make space for the grade-separated HS2 route, so some land acquisition outside the existing railway boundary would be required.

129

Stowe

Elmhurst

Rileyhill

Curborough

Nether StoweProposed Route

Tunnel

Viaduct


Slew of Existing Lines

0 0.30.15Km

cONNEcTION INTO THE WEST cOAST mAIN LINE


tHE lInk to BIrmInGHam5.30.

The next sections of the description of the Preferred Route concentrate on the link to central birmingham.

Water Orton to a452 Chester Road5.30.1.

Over this length, there is an existing triangular railway junction between the birmingham – Derby line and the Sutton Park line on the north side, which also has residential property constraints in the castle Vale area. Approaching the city, the first major obstruction is the A452 chester Road. East of chester Road, on the north side, there is substantial housing at castle Vale. Immediately west of chester Road on the north side there is industrial property; the south side is, relatively, free. A south-side widening is therefore proposed in this area.

The south side is largely unoccupied land, albeit that the River Tame runs in a canalised course on the railway’s southern boundary. The River Tame would need to be diverted approximately 20m southwards parallel to the existing river. Towards the A452, however, the south side also has industrial premises up to the chester Road. Therefore, it is proposed that HS2 would run on the south side, as a ground-level route.

131

Gilson

Walmley

Minworth

Lea Hall

Colehall

Shard End

Curdworth

Coleshill

Tile Cross

Kingshurst

Fordbridge

Water OrtonCastle Vale

Bacon's EndKitt's Green

Buckland End

Chelmsley Wood

Castle Bromwich

Proposed Route

Tunnel

Viaduct


0 0.40.2Km

THE LINK TO bIRmINGHAm


a452 Chester Road5.30.2.

The A452 is a dual 2-lane carriageway, carried over the railway. To the north of the railway, the A452 rises in elevation to meet the A47 Fort Parkway at an at-grade junction known as “Spitfire Island”. To the south, it reduces to a single 4-lane carriageway and passes under the m6, before connecting to a roundabout carrying the east-facing slip roads from the m6 at the castle bromwich junction.

There is therefore very little vertical flexibility on the alignment of the A452, albeit that there is some horizontal flexibility. Slab track and lowering existing ground levels could be considered to accommodate higher HS2 gauge. It would appear to be possible to construct a new A452 bridge alongside the existing, and then by means of a series of staged demolitions and new construction, re-create a dual-carriageway A452 at a higher level than existing to allow the higher HS2 gauge to pass under the structures. This would allow the proposed south-side widening.

133

Tyburn

Colehall

Bromford

Hodgehill

Pype Hayes

Castle Vale

Buckland End

Proposed Route

Tunnel

Viaduct


0 0.20.1Km

A452 cHESTER ROAD


M6 Crossing5.30.3.

HS2 lines would need to cross the alignment of the m6. Approaching the m6 crossing, the existing railway runs in a tight corridor between the A47 Heartlands Spine Road on the north side, and the viaduct carrying the m6 on the south side.

When the m6 was constructed, it had to cross from the south side of the Water Orton to birmingham lines near castle bromwich to their north side near Washwood Heath. To do this, the existing railway and the River Tame were crossed by a series of portal structures supported by lines of piers, which carry deck structures on which the m6 is aligned. The existing railway and river therefore lie under what is effectively a tunnelled structure, at minimum clearance over the existing railway. There are east-west openings through the structure, the southernmost of which carries the River Tame.

It is proposed to realign the River Tame outside and south of the m6 structure, and to utilise the river opening to carry the HS2 lines. This was found to be acceptable in gauging terms, provided that the HS2 tracks were about 1.5m lower than existing to achieve Gc gauge headroom. Some structural work would be required to strengthen the piers against train derailment. because of the proximity of the River Tame, these lowered tracks would have to be protected from flooding by constructing bunds along the full length of the diverted river channel. A benefit of the realignment would be that the river would become an open-air watercourse, rather than covered, with aquatic benefits. A “ground level” route for HS2 was therefore achieved, albeit that more investigation is needed on structural clearances and gauging to absolutely confirm the viability of passing under m6. An alternative might be to find an alignment following the chelmsley Wood collector Road.

135

Ward End

Bromford

Hodgehill

Erdington

Gravelly Hill

Birches Green

Proposed Route

Tunnel

Viaduct


Proposed Heartlands Roundabout

0 0.250.125Km

m6 cROSSING


a4040 bromford Lane and 5.30.4.

Heartlands Spine Road

The Heartlands Roundabout forms the junction of the Heartlands Parkway, A47 Fort Parkway and the A4040 bromford Lane north and south of the junction. There are traffic signal controlled junctions immediately north and south of Heartlands Roundabout that provide access into adjacent industrial areas. The circulatory carriageway of Heartlands Roundabout passes under the m6 motorway and over the existing railway. As a result, Heartlands Roundabout is extremely constrained by the surrounding infrastructure.

The proposed alignment of HS2 would be adjacent to the southern side of the existing railway lines. In order to provide the required railway headroom, the circulatory carriageway of Heartlands Roundabout would need to be raised. The ability to raise the circulatory carriageway of Heartlands Roundabout is constrained by the m6 motorway which passes over the junction. As a result, it is proposed to reconstruct the western part of the circulatory carriageway as a dual 2-lane carriageway with an amended vertical alignment to obtain the clearances required, but this would require a gradient possibly in excess of 4%. This would not change the minimum clearance under the m6 motorway. There would be a replacement roundabout to the south of the m6, with a realigned Heartlands Parkway and bromford Lane.

At this stage of the study, the proposals only considered highways alignments and not considered highway capacity. Nevertheless, the existing highway arrangements are likely to suffer from capacity issues due to the design constraints on the existing network. The proposals would need to be discussed with birmingham city council to satisfy them in terms of the proposed layout’s capacity.

This locality is the site of the proposed rolling stock maintenance depot, and this is described in the next section.

137

Proposed Route

Tunnel

Viaduct


0 0.10.05Km

A4040 bROmFORD LANE AND HEARTLANDS SPINE ROAD


The Rolling Stock Maintenance Depot5.30.5.

A site at Washwood Heath in birmingham was identified as a specimen location for a maintenance depot for the HS2 fleet. An indicative depot was developed, in order to determine the size and footprint requirements. HS2 Ltd provided the calculation on fleet size, based on assumptions of the total fleet size, and the number of units to be stabled or serviced overnight, in order to calculate the requirements in the midlands.

Key assumptions were made about issues such as:

Operational sequence•

Speed of connections from the main lines;•

Distances / spacings between tracks;•

Stabling sidings to provide cET •

and cleaning facilities.

standage requirements;•

wheel lathe provision;•

under frame cleaning facility;•

storage / offices facilities. •

Depot costs were estimated to cover

Depot signalling.•

OHLE•

Points heating•

Permanent Way•

Telecoms•

civils and Structures•

Fencing and security.•

Appendix H gives full details of the studies of the depot site.

139

THE ROLLING STOcK mAINTENANcE DEPOT

Saltley

Ward End

Nechells

Alum Rock

Gravelly Hill

Birches Green

Washwood Heath

Proposed Route

Tunnel

Viaduct


Proposed Heartlands Roundabout

Depot Boundary

0 0.250.125Km


bromford Lane to aston Church Road5.30.6.

between bromford Lane and Aston church Road, HS2 would lie on the southerly side of the existing line. This would sever existing siding connections to the south side premises, and sever the industrial link road bridge, but this could create a very convenient site for a rolling stock depot. The proposed Heartlands Roundabout could provide a highway connection to the depot.

The route would then pass, at a slightly lower level than existing, under Aston church Road and the Stechford to Aston line to its immediate north. There would be a realignment of Aston church Road to create adequate headroom.

141

Saltley

Ward End

Nechells

Alum Rock

Gravelly Hill

Birches Green

Washwood Heath

Proposed Route

Tunnel

Viaduct


0 0.250.125Km

bROmFORD LANE TO ASTON cHURcH ROAD


aston Church Road to fazeley Street Station5.30.7.

The route would run on the south side of the existing lines would then cross the Grand Union canal at existing rail levels before crossing under Saltley Viaduct. Due to the close proximity of the canal and Saltley Viaduct, it would not be possible to lower the HS2 lines. Saltley Viaduct would possibly need to be demolished and replaced to create adequate headroom.

between Saltley Viaduct and Fazeley Street Station, the route would then be on an elevated structure. This elevated structure would start to the west of Saltley Viaduct. The viaduct structure would be parallel to the existing lines before crossing over Duddeston Road sidings.

In order to allow the new route to cross from the southerly side of the existing railway to its north, a box structure is proposed over the existing lines. This box would stop as soon as practical after the crossing and the route would then run towards Fazeley Street Station on viaduct.

The viaduct would be located over Lawley Street depot and would then cross the existing cross-city line near Northumberland Street and St James’ Place.

The box structure could be avoided by realigning the HS2 lines further south of existing railway lines. This may also provide an opportunity to increase the throat speed, which is subject to a further study.

143

Aston

Witton

Tyseley

Saltley

Newtown

Digbeth

Ward End

Vauxhall

Nechells

Lee Bank

Highgate

Hay Mills

Erdington

Bordesley

Alum Rock

Sparkbrook

Birchfield

Small Heath

Gravelly Hill

Birches Green

Balsall Heath

Washwood Heath

Stockland Green

Netchells Green

Little Bromwich

Bordesley Green

BIRMINGHAM

Proposed Route

Tunnel

Viaduct


0 0.50.25Km

ASTON cHURcH ROAD TO FAZELEY STREET STATION


HS2 ltD’S PrEfErrED BIrmInGHam 5.31.

StatIon - fazElEy StrEEt

The preferred station location in central birmingham is near Fazeley Street.

General arrangement5.31.1.

The station would comprise three island platforms providing six platform edges. The platforms would serve 400m length trains and would be 10m wide, served by 3 banks of 2 escalators each distributing passengers to and from the high-level walkway at concourse level.

alignment5.31.2.

The horizontal alignments would be broadly parallel to the New Street to coventry line with a set of 80kph turnouts in the throat area, allowing all trains to access all platforms. These turnouts would be situated on straight tracks extending some 1km east of the platforms.

The vertical alignment was dictated by both the junctions to the east, and road clearances, particularly above New canal Road; the tracks terminate immediately west of Park Street causing its diversion. The proposed track level would be 116mOD which compares with the existing New Street line track level of between 111m and 113mOD.

145

FAZELEY STREET - STATION LOcATION


Concourse5.31.3.

The concourse would be located at high level above Park Street and would feed onto moor Street Queensway and hence moor Street Station. The concourse would also extend over the road to deliver passengers on the north side facilitating pedestrian access both to the business District (Snow Hill) and to New Street via the bull Ring Pedestrian Plaza.

The concourse building would act as a shared area for both the arriving and departing passengers, providing a seamless and integrated passenger experience to and from the New Street Station and city centre direction. The concourse would contain passenger and staff facilities, and as an inter-modal hub would also be able to offer retail opportunities.

The connectivity with New Street Station could be achieved by travelators connecting the bull Ring plaza at high level to the new HS2 station entrance concourses, and possibly by trams at street level providing safe inter-station movement without pedestrians crossing major roads. Taxis and buses would use a drop-off zone beneath the extended concourse, taking advantage of earlier provisions made along moor Street Queensway.

Platform Level5.31.4.

The high-level concourse would provide direct connections to a high-level walkway running above the centre platform with three transverse bridges providing travelator and escalator access to the platforms (two banks of three escalators for each platform, enabling platform clearance in 3 minutes).

Construction 5.31.5.

The station platforms (415m long and 10m wide) would be constructed on a new viaduct adjacent to the existing brick viaducts. These viaducts would vary in height up to approximately 8m.

A haul road could be formed from the Saltley Roundabout approximately 800m from the concourse beneath the void and station deck. This could subsequently be adapted to provide

additional access to the station and adjacent development.

Phasing 5.31.6.

The new Fazeley Street Station would be integrated into the adjacent developments currently envisaged as commercial offices and educational facilities. It is anticipated that the opportunity to develop above the station (air rights) and potentially above adjacent New Street lines would provide connectivity between the north and south sides of the railway corridor.

Through arch access would enable the majority of roads to be retained from New canal Road to the east but only pedestrian access across the rail corridor to the west of New canal Road.

147

FAZELEY STREET - cONcOURSE LEVEL

FAZELEY STREET - SEcTION


149

FAZELEY STREET - VISUALISATION


tHE altErnatE lInk to BIrmInGHam5.32.

This solution remains the second alternative behind the Water Orton corridor solution into birmingham.

M42 to birmingham International5.32.1.

At birmingham International Station, the new route would lie on the north side. A new island platform would be required (that would require the removal of the existing platform 5).

birmingham International to Marston Green5.32.2.

There is housing on both sides of the line approaching marston Green station, but generally the northerly side is less developed. It is therefore considered that a north side alignment for HS2 would be adopted.

Marston Green Station5.32.3.

At marston Green station, a symmetrical widening would be preferred. This would involve constructing a new island platform on the south side of the existing Down line, and then slewing it to the new face. The present Up line would then be slewed to the present Down face, with consequential re-arrangement of station access facilities, bridges, car parks etc.

Marston Green to Lea Hall5.32.4.

between marston Green and Lea Hall, a north side widening would be preferred. At the meadway, it would appear to be possible to construct a new bridge with appropriate spans and headroom, alongside the existing.

Lea Hall Station and Stechford5.32.5.

At Lea Hall station, a symmetrical widening would be preferred in view of constraints on both sides.

between Lea Hall and Stechford, the solution would be driven by the Stechford area. Stechford Station lies to the immediate of a fork of lines, the main route towards central birmingham, and the other towards Aston. A grade-separated junction would be needed.

Stechford Station lies towards the southerly side of the available formation, and a north-side

widening for HS2 would seem inevitable. In order to achieve the grade-separation, an elevated structure would begin east of Station Road, which would have to be re-aligned to the east, and raised. The HS2 elevated structure would pass over Albert Road to lie on the northerly side of the route towards New Street.

Stechford to adderley Park5.32.6.

It would be desirable for HS2 to lie to the southerly side of the existing railway approaching central birmingham, because of the less constrained nature of the area, and because it would suit connections into either of the new proposed stations, Fazeley or Warwick Wharf, in central birmingham. HS2 would be elevated over the Aston line and would then cross to the south side.

adderley Park to Landor Street and the City 5.32.7.

Centre Station

The south side widening would involve the demolition and replacement of Pretoria Road bridge as well as the acquisition from a waste recycling facility, and go-kart business, on the south side. Westwards from the Go-Kart facility, HS2 would be on elevated structure to approach whichever birmingham station was selected.

151

BIRMINGHAM

SOLIHULL

REDDITCH

ALDRIDGE

SUTTON COLDFIELD

Proposed Route

Tunnel

Viaduct


0 10.5Km

bERKSWELL TO bIRmINGHAm


tHE altErnatIvE BIrmInGHam StatIon - 5.33.

warwICk wHarf StatIon

General arrangement5.33.1.

Warwick Wharf station is HS2 Ltd’s second preference for a central birmingham station.

It would be sited in the fork of land between the New Street to coventry line, and the moor Street to Leamington line. The station would approximately bisect the space. The connectivity of the two sides of the HS2 line could still be achieved by the traffic and pedestrian linkages through the new viaduct arches serving the main stream of traffic and pedestrian movements. The station would be aligned approximately east-west with its approach curving back towards either the Water Orton corridor or the birmingham International corridor. The two new high-speed tracks would service two island platforms (six platform edges) each totalling 415m long and 10m wide forming the terminus.

The station would be aligned to avoid the Grade II listed buildings along its northern edge and would span over the Digbeth branch canal.

alignment 5.33.2.

The horizontal alignment was dictated by the connection with the two eastern approaches to maximise arrival and departure line speeds through the curves.

Vertical alignments would be constrained by the grade-separated junctions to the east and

the road clearance beneath (notably New canal Road). The tracks would terminate immediately to the east of Park Street to leave the road intact. The track level proposed would be 118mOD.

153

Aston

Digbeth

Vauxhall

Highgate

Bordesley

Netchells Green

BIRMINGHAM

Proposed Route

Tunnel

Viaduct


0 0.250.125Km

WARWIcK WHARF STATION - STATION LOcATION


Concourse 5.33.3.

The concourse would be located at high level above Park Street and the New Street Eastern Approach tracks. It would be approached from moor Street Queensway, with its entrances in a similar location to Fazeley Street. It is possible that the concourse could project over the road to deliver passengers to the north side, facilitating pedestrian access to the north (the commercial centre) and the west to birmingham New Street Station. connections to New Street Station would be enhanced by travelators from the concourse to the Plaza at high level, or by trams at street level.

The station would be constructed on new viaducts at a level of +10 to +15m above ground. It would be fully enclosed with a lightweight roof structure and noise barrier incorporated into both north-east and south-west façades.

Platform Level 5.33.4.

Platforms would be accessed by a high level walkway incorporating travelators serving three bridges with escalators to platform level. Each platform would be served by three banks of two escalators, enabling platform clearance in 3 minutes.

Construction5.33.5.

The station platforms ( 415m long ) would be constructed on a new viaduct varying in height up to approximately 10m high.

construction could be carried out in two phases with an initial 4- platform station subsequently augmented by two additional platforms as train service levels increase.

A haul road could be formed from the nearby Saltley roundabout running beneath the new deck and concourse locations. This could subsequently be adapted to provide new station access, and access to the surrounding site.

Phasing5.33.6.

It is anticipated that the new station would be an integral part of any future redevelopment of the area and its construction phasing would be planned accordingly.

Use of space beneath the new viaduct and potential construction above the station could provide valuable development opportunity.

155

WARWIcK WHARF STATION - cONcOURSE PLAN

WARWIcK WHARF STATION - STATION LOcATION


CoStS anD rISk5.34.

The table opposite presents the costs and risk summary for Route 3.

157

Route(3)

Route Length (km) 206.69

P/Way (#) 313,539,394 0.57%

Switches and crossings (#) 35,000,000 1.26%

OHLE (#) 173,618,588

Power supply (#) 78,128,365 10.26%

Signalling (#) 117,140,425 9.06%

communications (#) 83,169,702 1.46%

Stations 1,630,000,000 2.91%

Earthworks 634,526,481 7.65%

Retaining Walls 51,598,350

Structures 560,785,050

Tunnel 1,466,087,500

Road 90,010,600

Utilities 171,203,009

Additional items (construction) 473,162,500

base construction 5,877,969,963

Administration costs

Preliminaries & General Items 10.00% 587,796,996

Site Supervision 5.00% 293,898,498

Testing and commissioning (#) 5.00% 40,029,824

Training (#) 1.00% 8,005,965

Spares (#) 1.00% 8,005,965

base construction + On-costs 6,815,707,211

construction Risk 1,120,941,122

Ancillary Items 215,231,818

compensation 930,000,000

Total construction cost 9,081,880,151

HS2 costs

HS2 Project Management 8.00% 726,550,412

Design including consultancy charges (Legal,

Advisory etc.)

8.00% 726,550,412

Possession/Isolation management 17,467,433

RImINI costs 17,467,433

TOc compensation/Schedule 4 charges 139,739,462

Topo/GI surveys etc 31,000,000

Statutory charges 200,000,000

Depot / stabling 250,000,000

Programme construction risk allowance 1,104,916,667

cost escalation allowance -

Estimated Total Scheme cost inc. QRA risk 12,295,571,970


journEy tImE rESultS – routE 3 5.35.

The results are presented below for Route 3. These times can be regarded as equivalents to a timetabled WcmL run inclusive of performance / recovery time.

Timing Points Stops Route 3

London to birmingham Non-Stop 41m 26 s

Old Oak common Only 44m 09s

birmingham Interchange only

45m 46s

Old Oak and b’ham Interchange

48m 27s

London to Rugeley Non-Stop 43m 46s



51m 16s

birmingham to Rugeley Non-stop 14m 30s

London to WcmL Destinations such as Glasgow, manchester, Liverpool etc

About 23 minutes saving to Rugeley compared to present non-stop WcmL timings to Rugeley.

159


ROUTE 2.56.

IntroDuCtIon6.1.

This route was entitled “Route 2.5” as it lies between Route 2 (described later in the section on options not pursued) and Route 3 (the Preferred Route).

Route 2.5 would be identical to Route 3 (HS2 Ltd’s Preferred Route) from Euston to West Ruislip Station, and from mixbury (South of brackley) to Fazeley Street Station.

161

!

!

!

!

!

!

!

!

Birmingham

Brackley

West Ruislip

Princes Risborough

London

Warwick

Bicester

Solihull

High Wycombe


Route 2.50 9 184.5

Km

LINE OF ROUTE 2.5


wESt ruISlIP to DEnHam6.2.

From West Ruislip Station, the route would continue to the immediate north of the chiltern line with the corridor widening potentially affecting Ruislip Golf club. Along this length it may be possible to widen the corridor to the south, and slew the chiltern Lines over. The basis for this is that previously it has been planned to extend the LUL central Line along this length to Denham, and the adjacent properties are therefore set back from the existing rail lines. Whilst minimising the impact to the north of the rail corridor, this would bring the alignment slightly closer to the houses on the southern side.

1km west of West Ruislip Station, the chiltern Lines turn slightly to the south. The HS lines would also turn to the south with a matched horizontal radius of curvature. This would limit the line speed on the HS lines to 300kph, but this would have a minimal impact on the journey time as this is in close proximity to the 250kph limited section from West Ruislip to central London. The HS alignment would then maintain a line speed of 320kph until Princes Risborough.

The HS alignment would cross over the River Pinn on a new culvert and pass into a 1km long cutting which would be formed by widening the existing cutting utilised by the chiltern Line. The vertical alignment along this section would broadly match that of the existing chiltern Lines.

Upon emerging from the cutting and into the River colne valley, the HS alignment would cross this on a viaduct immediately to the north of the existing chiltern Line embankment and bridges. The 715m long viaduct would be relatively low with a maximum clearance above existing ground levels of 15m due to the vertical alignment mirroring that of the existing railway. Should this impose any unacceptable impacts it would be possible to change this to increase the clearance from the valley bottom by having the alignment on the viaduct rise to a vertical crest curve.

The viaduct would cross the Grand Union canal, the River colne and local tributaries and drains.

The length of individual spans and the locations of the piers would need to be determined based on detailed site investigations of the local ground conditions. Access would need to be provided to this area to allow construction as there are no roads in the immediate vicinity.

On the western side of the valley, the route would continue to follow the chiltern Line through Denham. This would necessitate the rebuilding of Denham Station to accommodate a new entrance and platform layout. Through Denham the existing rail corridor would need to be widened. It is envisaged that this could predominantly be carried out through slewing the chiltern Lines to the southern extent of the existing corridor and using structural measures to retain widened cuttings in the same manner as used between Old Oak common and West Ruislip. Detailed design of the alignment through this section based on the geotechnical properties of the existing cuttings would allow the extent of any necessary additional land requirements to be established.

To the west of Denham, the alignment would start to dip towards a tunnel portal. In this location it would also start to deviate from the chiltern Line to enable sufficient space for the retained cutting and the approach to the portal itself. The retained cutting would be 600m long with the tunnel portal being located to the north of Higher Denham. The retained approach would encroach upon the southern side of Denham Golf course.

lInE of routE 2.5

163

Denham

Ickenham

Hill End

Eastbury

West Hyde

Harefield

Willowbank

New Denham

Maple Cross

West Ruislip

Denham Green

Woodcock Hill

Uxbridge Moor

Ruislip Common

Newyears Green

Mount Pleasant

South Harefield

Ruislip Gardens

Northwood Hills

Harefield Grove

North Hillingdon

Hillingdon Heath

Batchworth Heath

RUISLIP

UXBRIDGE

NORTHWOOD

HILLINGDONProposed Route

Tunnel

Viaduct


0 0.750.375Km

WEST RUISLIP TO DENHAm


GErrarDS CroSS tunnEl 6.3.

This tunnel would be approx 4km in length, and would pass under Gerrards cross, emerging just west of Gerrards cross at chantry Wood, alongside the existing chiltern line, to the north side. The tunnels would be a twin-bores, each of 8.5m diameter, to allow 320kph running. There would be intermediate intervention shafts, but their locations have not been finalised.

165

Fulmer

Denham

Jordans Hill EndWest Hyde

New Denham

Iver Heath

Austenwood

Tatling End

Stoke Poges

Maple Cross

Gravel Hill

Denham Green

Baker's Wood

Wexham Street

Layters Green

Higher Denham

Butlers Cross

Mount Pleasant

Langley CornerHollybush Hill

Hedgerley Hill

Chalfont Grove

Hedgerley Green

Chalfont Common

Bottrells Close

Chalfont St Peter

Chalfont St Giles

GERRARDS CROSS

Proposed Route

Tunnel

Viaduct


0 0.750.375Km

GERRARDS cROSS TUNNEL


GErrarDS CroSS to HazlEmErE6.4.

Near Seer Green & Jordans, the existing chiltern Line would need to be slewed to the south to allow HS2 to pass between it and Seer Green. It would not realistically be possible to place HS2 to the immediate north of the existing chiltern Line without unacceptable effects on property.

The new route would lie a little to the south of the existing line’s footprint, avoiding direct property impacts on Seer Green, and the chiltern Line re-alignment would be to HS2’s south. The chiltern line re-alignment would be designed to achieve identical line speeds to the existing situation, but would involve the loss of woodland and part of a Golf course.

The HS2 route would then run in a series of deep cutting and viaducts up to 600m in length, to a tunnel portal at Hazlemere, about 1.2km east of Amersham Road, at Penn Wood.

167

CHESHAM

AMERSHAM

BEACONSFIELD

GERRARDS CROSS

Proposed Route

Tunnel

Viaduct


0 10.5Km

GERRARDS cROSS TO HAZLEmERE


HazlEmErE to PrInCES rISBorouGH6.5.

Tunnel - Hazlemere to Hughenden6.5.1.

between Hazlemere and Hughenden, the route would be in tunnel. The tunnel would be twin-bore, each of 8.5m diameter, to allow 320kph running. There would be intermediate intervention shafts, but their locations have not been finalised.

Hughenden Valley6.5.2.

At Hughenden, there would be a 720m length viaduct up to 20m from the valley floor.

Tunnel – Hughenden to Princes Risborough6.5.3.

most of the route from Hughenden to Princes Risborough would be in a twin-bore tunnel, each of 8.5m diameter, to allow 320kph running. There would be intermediate intervention shafts, but their locations have not been finalised.

There would be an intermittent length without tunnelling over a local valley in the Upper North Dean area. The tunnel would pass under the Speen and Lacey Green areas. The tunnel would pass under the existing chiltern Line north of Saunderton, and would emerge just west of Horsenden.

169

WENDOVER

HIGH WYCOMBE

PRINCES RISBOROUGH

Proposed Route

Tunnel

Viaduct


0 21Km

HAZLEmERE TO PRINcES RISbOROUGH


PrInCES rISBorouGH to BraCklEy6.6.

At the portal, the route would lie about 800m south of the existing chiltern line, and would then run in an almost straight line to converge with it near Haddenham. It would run almost alongside the chiltern line to chearsley. The route would continue in a straight alignment, north of chilton, and south of Dorton to avoid Rushbeds Wood (SSSI).

The route would then swing north to cross the chiltern line just north of Piddington. The route would be elevated to cross a flood plain, and this elevation would be used to bridge over the chiltern Line, without requiring its re-alignment, and then over the A41.

The route would then leave the chiltern Line corridor and strike across country. It would cross over the existing bicester to bletchley line (East-West Rail), and then pass east of Stratton Audley and west of Newton Purcell to join the alignment of Route 3 between mixbury and Finmere.

Route 2.5 would then be identical to Route 3 towards birmingham.

171

OXFORDTHAME

WENDOVER

BRACKLEY

BICESTER

AYLESBURY

BUCKINGHAM

MILTON KEYNES

PRINCES RISBOROUGH

Proposed Route

Tunnel

Viaduct


0 31.5Km

PRINcES RISbOROUGH TO bRAcKLEY


CoStS anD rISk6.7.

The table opposite presents the costs and risk summary for Route 2.5.

173

Route(2.5)


P/Way (#) 318,629,454 4.99%


OHLE (#) 176,885,228 2.77%

Power supply (#) 79,598,353 1.25%

Signalling (#) 116,440,905 1.82%


Stations 1,630,000,000 25.50%

Earthworks 594,101,807 9.29%

Retaining Walls 42,359,450 0.66%

Structures 495,525,470 7.75%

Tunnel 2,094,398,000 32.77%

Road 90,104,740 1.41%

Utilities 186,164,368 2.91%

Additional items (construction) 451,162,500 7.06%






Training (#) 1.00% 8,078,270

Spares (#) 1.00% 8,078,270

base construction + On-costs 7,406,937,703



compensation Prov sum

930,000,000


HS2 costs

HS2 Project Management 8.00% 805,369,664

Design including consultancy charges (Legal, Advisory etc.) 8.00% 805,369,664








cost escalation allowance

Estimated Total Scheme Cost inc. QRa risk

13,259,451,122


journEy tImE rESultS – routE 2.5 6.8.

The journey time results are presented below for Route 2.5. These times can be regarded as equivalents to a timetabled WcmL run inclusive of performance / recovery time.

Timing Points Stops Route 2.5

London to birmingham Non-Stop 43m 08s



47m 27s


50m 06s

London to Rugeley Non-Stop 45m 33s



52m 57s

birmingham to Rugeley Non-stop 14m 30s

London to Wcm Destinations such as Glasgow, manchester, Liverpool etc

Approx 1m 40s slower than Route 3

175


This route would be identical to Route 3 (HS2 Ltd’s Preferred Route) from Euston to Old Oak common, and would include the proposed Old Oak common station.

olD oak Common to kInGS lanGlEy 7.1.

tunnEl

The route would run in tunnel from Old Oak common to Kings Langley, consisting of twin 7.25m internal diameter tunnels, connected by cross-passages at 250m intervals, allowing speeds up to 225kph.

The alignment through the Old Oak common station box would be straight and level. This would facilitate the design of the necessary turnouts to serve each of the platform faces. Immediately to the west of the station box, the alignment would swing to the north in a curve with a radius of 3,000m. This curve could allow 240kph, but the tunnel would allow only 225kph, and there would be the proposed station. All this would result in minimal journey time impact. North of this curve, the route would run in a straight alignment to the tunnel portal at kings Langley. This alignment would need to be reviewed through the design development phases to minimise the effects of settlement on extensive areas of domestic properties and industrial zones. This would involve routing the tunnels beneath open ground, gardens and roads as much as possible, subject to sensitivity assessments. There are areas where the current alignment is adjacent to open space but currently under properties, and where possible this would be improved upon. However it is not considered likely that this would significantly affect the length of the tunnel.

There are limits to how the alignment of the tunnels could be modified to follow surface features. consideration would also need to be given to achieving a balance of the land use above both of the tunnels, and whilst it is possible to vary the distance between the bores, this would have impacts on the cross-passage design and alignment.

The design of the vertical alignment was based on minimising the gradients as far as is possible, whilst keeping this in balance with the resulting quantity of tunnels and viaducts required. The vertical profile assumed constant gradients between fixed points such as station box locations and minimum clearances to roads and railways; it does not account for sub-surface obstacles and an assessment is ongoing of impacts these may have on the profile.

The design of the tunnelled alignments would need to give consideration to the construction techniques, and the vertical profile may be refined to provide more homogenous geotechnical parameters for the Tbms to operate within. maintaining a set depth may result in excessive variety in the substrates tunnelled through, with a significant impact on Tbm design, construction rates and associated project risk.

Immediately to the north of the m25 the topography rises steeply. Whilst it would be preferable to site a tunnel portal immediately to the north of the m25, this would result in the rail alignment continuing at a very steep angle and in a deep cut approximately parallel to the adjacent ground level as it rose to the north. The alignment would therefore continue in tunnel, but would climb steeply to the tunnel portal location at the top of the hill. The portal would be located to the north of chipperfield Road, and due to its siting on the edge of a hillside would only require a 250m long approach structure.

Intervention shafts would be needed, and it was assumed that there would be fourteen of these. The design of the shafts would vary depending on their location relative to the tunnels, whether they were also being used for ventilation purposes and the depth of the tunnels. Larger shafts may be required should access be needed to the Tbms at intervals along the drive to facilitate maintenance and repair.

ROUTE 47.

177

!

!

!

!

!

!

!

Birmingham

Catesby

Watford

Kings Langley

Lower Shuckburgh

Leighton Buzzard

London

Milton Keynes


Route 40 9 184.5

Km

LINE OF ROUTE 4


kInGS lanGlEy to CHEDDInGton 7.2.

North of the tunnel portal, the line speed would rise to 400kph and this governs the alignment design. The increased radii required affected the extent to which the route could avoid major constraints.

At the tunnel portal, the alignment would be heading in a northwest direction. Upon reaching the surface, the alignment would then swing round to head on a more westerly bearing. In doing so, it would cross the northern side of Scatterdell’s Wood and a number of roads although the majority of the land crossed is currently used for agricultural purposes. The roads which are crossed would either be routed in new over or under bridges, or locally diverted to connect to other roads in the immediate vicinity.

Due to the steep gradient at the northern end of the tunnelled alignment and the topography of the ground to the north of the tunnel portal, significant embankments would be needed. These would be up to a maximum of 15m above the existing ground level. During the detailed design it may be possible to reduce the height although this would result in deeper cuttings on the adjacent sections of route and on the approach to the tunnel portal.

The route would continue to run to the north of bovingdon and bovingdon Airfield. Along this stretch it would affect five roads and pass near a number of domestic properties. The alignment would generally be at grade although where it passes through the Little Hay Golf course a significant cutting would be required. This would extend to a depth of 18m but is required as the alignment could not mirror the topography. Detailed design may reveal that it would be possible to utilise a section of cut and cover tunnel in this location. This would also serve to minimise the long term impact on land usage.

To the north of bovingdon, the alignment would continue to run in a westerly direction across a number of transverse valleys. These have a

maximum height difference of 25m from the valley bottom to hill top, and crossing these would necessitate deep cuttings and high embankments. The vertical alignment was designed to minimise impact by crossing at mid-height, thus the minimising the depths of cutting and heights of embankment. Towards berkhamsted, the route would cross a number of small woods. crossings would be provided where the route would cross footpaths and agricultural tracks.

To the south of berkhamsted the alignment would pass between Haresfoot Farm and Haresfoot School and then coincide with the A41. maintaining the alignment to the south of the A41 would result in speed restrictions, and the route would run through school buildings. It would also require a long and complex slewed crossing of the A41 further along the route. It was therefore deemed preferable to locate the route north of the A41 for the stretch where it drops down from the chiltern Hills to the Grand Union canal adjacent to Tring Station.

The impact of routing to the north of the A41 is that it would coincide with it at two locations. The first of these is between the intersection with the A416 chesham Road and cock Grove, where the A41 would need to be realigned to the south for a distance of 2km. This would also necessitate the provision of a new overbridge where the line passes over the A41. A benefit of realigning the A41 in this location is that it would reduce the radius on the existing bend. The second location is at the foot of the hill where the Newground Road passes over the A41. This would require a 1km length to be realigned to the south and this would involve extending the existing cutting into the hillside.

Along the alignment by the A41, the route would drop down and move towards the West coast main Line. The surrounding topography would result in lengths of cutting and embankment, each typically less than 5m deep or high.

In the vicinity of New Ground, the A41 swings around to the west and the route would continue

179

TRING

LUTON

CHESHAM

AMERSHAM

DUNSTABLE

CHORLEYWOOD

BERKHAMSTED

RICKMANSWORTH

HOUGHTON REGIS

HEMEL HEMPSTEAD

LEIGHTON BUZZARD

Proposed Route

Tunnel

Viaduct


0 21Km

KINGS LANGLEY TO cHEDDINGTON


in a northerly direction passing immediately to the east of Pendley manor Hotel and conference centre in a shallow cutting. It would then cross over Station Road and the Grand Union canal on a low 520m long viaduct.

The line would then cross the West coast main Line near Pitstone, running between the settlement and the railway. Approaching cheddington, the route would lie immediately east of the current Tring cutting on the WcmL.

CHEDDInGton to wHaDDon7.3.

The route would pass to the east of cheddington, and would run parallel to the existing WcmL. Approximately two kilometres north of cheddington, the line would re-cross the WcmL and head toward Ledburn, continuing towards Whaddon. Due to a flood plain in the Ledburn area and a general height increase of the adjacent relief, the line would be on a viaduct and embankment, and would then move into a cutting north of Ledburn. Raising the line to the south of Ledburn would decrease the quantity of cut.

The route would be generally unaffected by the topography between Ledburn and beachhampton, with the ground level gently undulating between these two locations. Localised areas would require cutting, but the route would generally be on embankment.

181

TRING

AYLESBURY

MILTON KEYNES

LEIGHTON BUZZARD

Proposed Route

Tunnel

Viaduct


0 21Km

cHEDDINGTON TO WHADDON


wHaDDon to CatESBy 7.4.

From the Whaddon and beachhampton area to Wicken, the line would be at ground level after traversing a flood plain on viaduct at beachhampton. From Wicken, the line would head north-west, passing East Ashalls copse SSSI.

The route would continue at or about ground level to the east of Nash, and to the west of beachampton, and would cross the River Great Ouse near mount Hill Farm. This would allow for the expansion of bletchley/milton Keynes into the potentially designated areas for new housing developments.

It would then run at or about ground level between Wicken and Deanshanger, then east of Whittlebury. In doing so, it would avoid environmental features such as Scheduled monuments, Park and Gardens. The line at this point would traverse Whittlewood Forest (a designated SSSI and Park and Garden). There is little scope for the horizontal alignment to change due to the close proximity of the Silverstone race track and the town of Towcester. There are plans for Towcester to expand towards Wood burcote - this was taken into consideration and the line would not affect the development of the town. The line would cross a series of waterways including the river Towe and elevated structures would need to be constructed in order to cross these obstacles.

The route would pass under the A43 north of Silverstone, and there would be a viaduct over the flood plain before passing west of bradden and blakesley, and east of Adstone.

183

DAVENTRY

BRACKLEY

BICESTER

BUCKINGHAM

NORTHAMPTON

Proposed Route

Tunnel

Viaduct


0 31.5Km

WHADDON TO cATESbY


CatESBy nEw tunnEl7.5.

At catesby, the route would move towards the disused Great central Railway alignment and its tunnel at catesby, and would face the same topographical challenges. There were a number of alignment options:

the tunnel could be over-bored and made •

structurally sound to meet HS2 requirements

a wholly new twin-track tunnel could •

be constructed alongside

the existing tunnel could be used for one •

track, and a new single-track tunnel provided.

It was assumed that the tunnel would be twin-bore tunnels, each of 11.0m diameter to allow continued 400kph running. It is possible that further route refinement could occur in this area, aimed at reducing the length of the new tunnel.

185

DAVENTRY

Proposed Route

Tunnel

Viaduct


0 0.90.45Km

cATESbY NEW TUNNEL - TO LOWER SHUcKbURcH TUNNEL


CatESBy to lowEr SHuCkBurGH7.6.

Upon exiting the catesby tunnel, the line would pass onto viaduct to cross the River Leam and its associated flood plain.

187

Hellidon

Flecknoe

Nethercote

Upper CatesbyLower Catesby

Lower Shuckburgh

Proposed Route

Tunnel

Viaduct


0 0.50.25Km

cATESbY TO LOWER SHUcKbURGH


lowEr SHuCkBurGH tunnEl 7.7.

The route would go into a further tunnel to pass under challenging topography east of Lower Shuckburgh; this would also avoid features of environmental interest. It was assumed that the tunnel would be twin-bore tunnels, each of 11.0m diameter to allow continued 400kph running.

189

Flecknoe

Nethercote

Lower Shuckburgh

Proposed Route

Tunnel

Viaduct


0 0.40.2Km

TO LOWER SHUcKbURcH TUNNEL


lowEr SHuCkBurGH to CraCklEy7.8.

North of Lower Shuckburgh tunnel, the line would cross the Grand Union canal and pass along relatively flat topography. There are many tributaries to the river Leam from Lower Shuckburgh to marston, and the area is subject to flooding, so lengths of line would have to be elevated. This area has scattered settlements; the route as currently proposed sought to find an acceptable alignment between broadwell, Leamington Hastings and birdingbury.

The line would pass to the northwest of marton, then cross the River Leam and rise up with the surface topography through Wappenbury Wood.

The route would then pass south of bubbenhall, affecting a proportion of a SSSI and would then cross the River Avon.

The route would then cross the River Sowe between the Finham Sewage Works and Stoneleigh village, aiming to avoid or minimise the effect on Stoneleigh National Park and Garden.

The route would then be placed in a jacked box structure under the A46 Kenilworth Eastern bypass and would cross Finham brook. It would be jacked under the Leamington – coventry line, then pass below the A429 and cross a flood plain, which are in close succession.

191

COVENTRY

RUGBY

WARWICK

NUNEATON

HINCKLEY

BEDWORTH

KENILWORTH

ATHERSTONE

LUTTERWORTH

STRATFORD-UPON-AVON


Proposed Route

Tunnel

Viaduct


0 31.5Km

LOWER SHUcKbURGH TO cRAcKLEY


routE tErmInatIon – CraCklEy7.9.

The line would then progress towards the disused railway line north of Kenilworth. The line would then adopt the alignment of the Preferred Route, Route 3.

193

COVENTRY

WARWICK

KENILWORTH


Proposed Route

Tunnel

Viaduct


0 10.5Km

ROUTE TERmINATION – cRAcKLEY


total routE 4 CoStS anD rISk 7.10.

The table opposite presents the costs and risk summary for Route 4.

195

Route(4)


P/Way (#) 317,167,586 4.49%


OHLE (#) 175,042,340 2.48%

Power supply (#) 78,769,053 1.12%

Signalling (#) 115,684,857 1.64%


Stations 1,630,000,000 23.07%

Earthworks 662,069,774 9.37%

Retaining Walls 20,436,950 0.29%

Structures 461,576,850 6.53%

Tunnel 2,817,508,275 39.88%

Road 98,944,400 1.40%

Utilities 205,757,965 2.91%

Additional items (construction) 365,662,500 5.18%






Training (#) 1.00% 8,024,001

Spares (#) 1.00% 8,024,001

base Construction + On-costs 8,180,178,323



compensation Prov sum 930,000,000


HS2 costs

HS2 Project management 8.00% 851,973,852

Design including consultancy charges (Legal,

Advisory etc.)

8.00% 851,973,852








cost escalation allowance

Estimated Total Scheme cost inc. QRA risk 13,900,416,101


journEy tImE rESultS – routE 47.11.

The journey time results for Route 4 are presented below. These times can be regarded as equivalents to a timetabled WcmL run inclusive of performance / recovery time.

Two timings are presented, for differing speeds in the Old Oak common to Kings Langley tunnel. This tunnel would have a 225kph capability, the same as the Euston to Old Oak common tunnel. Other routes’ tunnels through the chilterns would however have a 320kph capability, so Route 4 would not achieve 320kph running for some relatively larger distance from London.

A sensitivity test was undertaken using 320kph in the tunnel. The time saving would vary depending on stopping patterns, but would typically be about 2 minutes. The cost difference would be in the order of £200 - 300m.

Timing Points Stops Route 4

with 225kph

Kings Langley Tunnel

Route 4

with 320kph

Kings Langley

Tunnel

London to birmingham Non-Stop 42m 51s 40m 50s

Old Oak common Only 45m 43s 43m 33s


47m 17s 45m 08s


50m 01s 47m 51s

London to Rugeley Non-Stop 45m 20s 43m 10s

Old Oak common Only 48m 03s 45m 53s


52m 50s 50m 39s

birmingham to Rugeley Non-stop 14m 30s 14m 30s

London to Wcm Destinations such as Glasgow, manchester, Liverpool etc

Approx 1m 30s slower than Route 3

Approx 35s faster than Route 3

197


IntroDuCtIon8.1.

Following the sifting process, six options were identified for stations in the immediate vicinity of Heathrow Airport. These comprised:

A Terminus Station at Terminal 5; •

A Through Station at Terminal 5; •

A Terminus Station at Terminal 6; •

A Through Station at Terminal 6; •

A Through Station at Iver; •

A Terminus Station at Iver.•

These six locations were considered with three route alignment options (through, loops and spurs). The through station options would be compatible with loops although the through route alignment option was not pursued, all six stations options remained live pending the results of the demand model and a further report on the relative benefits associated with each would be needed.

tErmInal 5 – tErmInuS StatIon8.2.

The proposal would comprise a four-platform edge (two island platform) serving four fully reversible lanes. The station would be built within a cut-and-cover box with tracks at -1 level (approx. 7.5m below ground). The station would be aligned north/south adjacent to the local road immediately west of the T5 car park. This alignment would be dictated by land availability and sub-surface access to the north beneath the road network.

Sites on the Heathrow Apron were not pursued due to excessive airport operation disruption associated with a construction of this magnitude.

The station would be served by two tracks from the north as a spur from the Route 3 passing beneath the local road network (hence its north-south alignment).

Access to the station would be at approximately 3m below ground level via a travelator to the

shared concourses beneath T5 for Heathrow Express, Piccadilly Line and Airtrack.

In the event that international HS2 services were required, an additional dedicated platform would be provided.

OPTIONS FOR cONNEcTING TO HEATHROW8.

199

Longford

Stanwell Moor

Proposed Route

Tunnel

Viaduct


0 0.20.1Km

TERmINAL 5 – TERmINUS STATION - LOcATION PLAN


tErmInal 5 – tHrouGH StatIon8.3.

The Terminal 5 Through Station would be located on a two-track loop dropping down to the south of Route 3.

The station would comprise four-platform edges (two island platform) serving four lines (two up, two down). The station would be constructed within a cut-and-cover box with tracks at -1 level (approx. 7.5m below ground, passing above the Airtrack tunnels [approx. 15m below ground]). The station would be aligned north/south adjacent to the T5 car park and local road, taking advantage of land availability whilst avoiding disruption to airport operations. .

The station would be served by two tracks from the north passing beneath the local road network. To the south the box would be extended approximately 300m to enable the two southbound tracks to descend into tunnel portals (track level approx. 15m below ground). These tracks would then loop round beneath the airport avoiding existing airport infrastructure to form a loop from Route 3.

Access to the station would be at approximately 3m below ground by travelator into the shared concourse beneath T5 for Heathrow Express, Airtrack and the Piccadilly Line.

In the event of an International service requirement an additional dedicated platform would be provided.

Provision for crossovers at either end of the station was not included.

201

Longford

Stanwell Moor

Proposed Route

Tunnel

Viaduct


0 0.20.1Km

tErmInal 5 – tHrouGH StatIon - LOcATION PLAN


tErmInal 6 – tErmInuS StatIon8.4.

The Terminus Station would comprise four-platform edges (two island platforms) serving four reversible lines. The station would be served by two tracks from the north forming a spur from Route 3.

The station would be built within a cut-and-cover box with tracks at -2 level (approximately 15m below ground) to facilitate tunnel portals to the north. The station would be aligned north-south located beneath the new Runway/Taxiway and the new Terminal 6.

Access to the station would probably be via a concourse at -1 level (7.5m below ground level) beneath Terminal 6.

If International services were required, an additional dedicated island platform would be provided.

The location of the station would be dependent on the future terminal design and therefore the current proposals are indicative only.

203

Sipson

Longford

Harmondsworth

WEST DRAYTON

Proposed Route

Tunnel

Viaduct


0 0.20.1Km

TERmINAL 6 – TERmINUS STATION - LOcATION PLAN


tErmInal 6 – tHrouGH StatIon8.5.

The through station would be served by a two-track loop dropping down from Route 3.

The through station would comprise four platform edges (two island platforms) serving two up lines and two down lines. The station would be constructed in a cut-and-cover box with track at -2 level (approximately 15m below ground) to facilitate provision of tunnel portals at both ends of the box for the two eastbound and the two westbound lines.

The station would be aligned east-west to optimise alignments for the track loop which would serve it from Route 3.

Access would probably be provided via a concourse at -1 level beneath the new T6 Terminal.

If International services were required, an additional dedicated platform would be provided.

Provision for crossovers at either end of the station was not included.

205

Sipson

Longford

Harmondsworth

WEST DRAYTON

Proposed Route

Tunnel

Viaduct


0 0.20.1Km

TERmINAL 6 – THROUGH STATION - LOcATION PLAN


IvEr – tHrouGH StatIon8.6.

The HS2 through station would comprise four platform edges (two islands) serving two Up and two Down lines. The station would be located east-west alongside and to the north of the Great Western main lines and Relief Lines at, or marginally above, ground level.


The Great Western Fast Lines and Relief Lines would be realigned to provide platforms for all four lines serving GWmL and crossrail. Interchange with HS2 would be via a raised concourse above the station.

HS2 would be served by a two line loop from Route 3 in each direction.


It was assumed that the new terminus would surround this station and provide access (via a people mover) to the main airport terminals.

207

Iver

Cowley

Thorney

Love Green

Richings Park

Harmondsworth

Cowley Peachy

Proposed Route

Tunnel

Viaduct


0 0.40.2Km

HEATHROW HUb – THROUGH STATION - LOcATION PLAN


IvEr – tErmInuS StatIon8.7.

The Terminus Station would also be aligned east/west and served by two tracks from the east as a spur.

The station would comprise four platform edges (two islands) serving four fully reversible lanes. GWmL facilities and interchange facilities would be identical to those of the through station, as would access to the hub and main airport.


209

Iver

Cowley

Thorney

Love Green

Richings Park

Harmondsworth

Cowley Peachy

Proposed Route

Tunnel

Viaduct


0 0.40.2Km

HEATHROW HUb – TERmINUS STATION - LOcATION PLAN


traCk alIGnmEnt oPtIonS – looPS, 8.8.

SPurS anD tHrouGH routES

Three options were considered for serving the T5, T6 and Iver station locations. These comprise a loop solution, and spur solution and a through route.

Loop solutions. There would be a loop off •

the main HS2 alignment (Old Oak common to Ruislip). The deviation points would depend on which line was being considered. The loops would comprise a junction from the main line to both the east and west of each Heathrow station option, with up and down lines through the station. This arrangement would allow the trains not timetabled to stop at Heathrow to continue on the direct alignment.

Spur solutions. There would be a •

triangular junction on the main HS2 alignment (Old Oak common to Ruislip section) with spurs approaching each of the Heathrow Station location options.

Through Routes. From London, the HS2 •

Route would pass through the Heathrow station location. It would then continue to the west and connect to whatever alignment was chosen through the chilterns. All HS2 trains would pass Heathrow, and some (undefined) would stop there. There would need to be acceleration and deceleration lines each side of the station. It would be necessary to have a turnout from the non-stopping through lines approximately 2.5km to the east and west of the station box. These would require areas of open cutting extending to the depth of the tunnels which would be carrying the HS trains on this route alignment out of London. Trains stopping at the station would branch off at the turnouts and enter separate dedicated tunnels leading to the station.

On the basis of the above, the through route options were not pursued. Options for the loops and spurs to each of the Heathrow station locations were retained.

looP DESIGn from routE 38.9.

Deviation Point for the Station Options8.9.1.

The eastern connection point would be in the Northolt area, with the tunnel portal for the twin tunnels to Heathrow being located immediately to the east of the Hillingdon Waste Transfer Station. There would be a connection at this location to both the Up and Down mains from London. This would require a grade-separated junction for the turnouts, which would be designed to maintain a line speed of 230kph on the spur.

The siting of the tunnel portal would require consideration of a number of factors, of which the key ones are described below:

to minimise the route length to each •

of the Heathrow station locations, so as to both minimise the journey time and the construction cost;

to allow a suitable track geometry to •

maintain high speed through the turnout and on the route to Heathrow;.

Availability of space to allow the branch •

off from Route 3. The junction would comprise the through HS lines and the Up and Down mains on the loop to Heathrow. There would also need to be a grade-separated junction. This would require a greater width of rail corridor than necessary for the through HS lines.

The tunnel portal would be located to the north of Route 3, and once the tunnels had started these would swing round to the south and cross under the through HS lines. The alignment would then pass under the A40 and under fields towards Hayes Park and Hayes End. From this point the alignment design would be specific to which of the Heathrow station options was to be served.

The tunnel alignment from the Northolt portal to Hayes End would generally provide at least 15m cover from the crown of the bored tunnel to the ground surface. The vertical alignment design was based on keeping the tunnels as shallow as is practical, but the depth of cover could be increased by lowering the vertical alignment.

211

ST ALBANS

Proposed Route

Tunnel

Viaduct


0 42Km

TRAcK ALIGNmENT OPTIONS – LOOPS, SPURS AND THROUGH ROUTES - LOcATION PLAN


Along each of the loops intervention shafts would be included at intervals of approximately 2km. In some locations, the shafts and their associated hard-standing for maintenance and emergency vehicles would necessitate local modifications to roads or the provision of access from adjacent roads.

Loop to T58.9.2.

The twin bored tunnel alignment would continue from Hayes End and pass beneath Stockley Park, Drayton and the m4 on its approach to the perimeter of Heathrow. It would then cross under the runways to the west of the terminal complex for T1 – T4. In order to pass through the north-south orientated T5 station location, the alignment would then swing around steeply in a curve limiting speed to less than 130kph. As the bend would be near the station, and trains would either be already braking or still accelerating at this point, the impact on the speed profile would be minimal.

Under the southern side of Heathrow airport, the tunnels would not run under the runway but would be in areas utilised for aircraft taxi-ing to and from the terminals. Within the Heathrow airport footprint, the tunnelled alignment would need to avoid existing subsurface infrastructure, and this may require variations to both the vertical and horizontal alignments. It is envisaged that it would generally be possible to route the tunnel beneath the existing subsurface infrastructure at Heathrow, but this would need to be confirmed. The only constraint on the depth that the tunnels can run at under Heathrow would be the track level in the T5 station. This, in conjunction with the maximum permitted gradients on the alignment, would dictate the depth achievable with distance from the station.

As the alignment continues to swing around to the head in a northerly direction at the western end of the Heathrow airport, the vertical alignment would start to rise up in order to be at an appropriate level at the T5 station location. The risks associated with this shallower tunnel would need to be considered in detail, and mitigation

measures developed for any impacts on adjacent buildings and infrastructure. It may be necessary to steepen the gradient of the alignment into the station to maintain the maximum levels of cover practicable. It is considered unlikely that this section could be constructed as a cut and cover tunnel due to the significant roads, watercourses and airport infrastructure above the alignment of the tunnel.

The alignment would then pass through the T5 station.

To the north-east of the T5 station, the alignment would again dip down to gain sufficient cover to the tunnels. It would then continue in a northerly direction under the m25 and then the m4 immediately to the west of its junction with the m25. It would continue on under Richings Park, and Iver in a straight alignment to the west of the m25.

213

ST ALBANS

Proposed Route

Tunnel

Viaduct


0 42Km

LOOP TO T5 - LOcATION PLAN


Loop to T68.9.3.

The twin bored tunnel alignment to T6 would lie further to the east of that described for T5, as the through station orientation would be east-west. The alignment would pass under the Warnford Industrial Estate, the m4 and swing round from a southerly direction to a westerly direction under Harlington. The radius of the curve would limit speed to 200kph. As this bend would be near the station, and trains would either be already braking or still accelerating at this point, the impact on the speed profile would be minimal.

between Harlington and Simpson, the alignment would pass beneath the existing LUL Piccadilly line tunnels to Heathrow and a spur from the m4 into Heathrow. It is envisaged that the alignment would pass under these key transport links, but the depth of the LUL tunnels is not known. These therefore have the potential to affect the alignment. As there would only be 800m from the crossing location of the tunnels to the station box, there would be very limited scope to achieve significant changes in the vertical profile of the tunnels.

The crossing beneath the m4 spur could require modifications to the alignment. The m4 runs in a cutting at this location, and there is very little clearance from the proposed tunnel to the road level. Accurate site information would be required to determine the level of the ground. If the clearance would result in undue subsidence risks, the alignment would need to be lowered. This could affect the station design as the close proximity of this constraint to the station does not allow much distance to achieve changes in the vertical profile.

Having passed through the station at T6 in an east-west alignment, the continuation towards the West midlands would dip back down to achieve sufficient cover and swing around in a northerly direction. The radius of the curve would limit speed to 150kph. As this curve would be near the station, and trains would either be already braking or still accelerating at this point, the impact on the speed profile would be minimal.

The alignment would pass beneath Harmondsworth moor and the junction of the m25 and the m4. In this location, the tunnel would be between 20 and 30m below the ground level. The road junction is complex and includes many grade-separated elements. It would be necessary to ascertain the depth of the supporting foundations and ensure that these would not coincide with the alignment of the tunnels.

Once north of the m4, the alignment would turn to the north and pass beneath Richings Park, the Great Western main Line, the Grand Union canal and Iver. From this point, the alignment would follow the common alignment with the other loops as described below.

215

ST ALBANS

Proposed Route

Tunnel

Viaduct


0 42Km

LOOP TO T6 - LOcATION PLAN


Loop to 8.9.4. Iver

The twin bored tunnel alignment to the Iver would lie further to the west of that described for T5 as the Hub station through station orientation would be east-west, and the station would be located 4km to the north of T5. The alignment would therefore pass under Yiewsley and swing progressively round to a westerly direction. The radius of the curve would limit speed to 200kph. As this bend would be near the station, and trains would either be already braking or still accelerating at this point, the impact on journey times would be minimal.

The station would be at approximately ground level. This could be constructed at a lower level through the use of a cut and cover box. This would result in increased cost, and complicate the passenger movements for people transferring between the HS route and the Great Western main Line. The impacts of the latter could be partially mitigated through the design of the station, and this would need to be considered further as the design was progressed.

This location of the station at ground level would require the tunnelled alignments to rise up to tunnel portals to the east and west of the station. between the station and the tunnel portals, the alignments would be contained in structurally retained cuttings.

To the east of the location lie extensive flooded gravel pits, the River colne and the Grand Union canal. Immediately to the east are extensive areas of residential and industrial property. The alignment was designed to minimise the impact on these constraints, and would remain in tunnel until immediately to the west of the River colne. At this point, the tunnel portal would be sited.

In order to be able to achieve the necessary reduction in level from the station to the tunnel portal, the alignment would need a gradient of 3.5%, the maximum permitted by the project specification. It would also require the radius of curvature on the vertical curves to be reduced to the minimum permitted. This alignment would therefore be at the limit of its design.

construction of the approach to the tunnel portals would probably be in saturated ground conditions beneath the water table. Whilst feasible to construct in these conditions, extensive dewatering would be required. The tunnel portal to the east of the station would lie within the flood plain. This would need to be flood protected until the alignment is above the maximum flood level. Due to the potential impact of flooding to the tunnel, the design of the flood protection should be based on at least a 1 in 1,000 year design storm event. The flood defences to the tunnel portal would need to extend along the approach to the tunnel portal until the ground level around the retained approach is above the design flood level.

The m25 is located immediately to the west of the Iver station location. As the station would be at ground level and the m25 is on a raised embankment, it would be necessary to cross the m25 in a very shallow tunnel. It was assumed that a jacked box would be utilised. If there were insufficient cover to allow this without incurring excessive risk, alternative methods would be utilised. These may include progressively constructing a cut and cover box through the motorway with extensive temporary traffic management on the m25. The location of the station would affect the width of corridor that is required beneath the m25 as it is possible that the station throat would extend through this location.

West of the m25 and the station throat, the alignments would dip down to a tunnel portal immediately to the south of the Grand Union canal Slough Arm. On the approach to the tunnel portal, the alignment would swing around to a north-west direction and once in tunnel would continue until it was heading north. The horizontal alignment would restrict speeds to 130kph. As this would be near the station, and trains would either be already braking or still accelerating at this point, the impact on journey times would be minimal.

The northerly-heading alignment would pass under Iver and would then follow the common

217

ST ALBANS

Proposed Route

Tunnel

Viaduct


0 42Km

LOOP TO IVER - LOcATION PLAN


alignment with the other loops as described below.

Surface Option from the Heathrow stations8.9.5.

This option is preferred by HS2 Ltd.

North of Iver, the loops through each of the stations options would recombine and then follow the same alignment to the connection point. This would initially comprise a straight, northerly, tunnelled alignment running to the west of the m25, and crossing beneath it to the north-east of Iver Heath. The alignment would continue in the same direction and having passed beneath the m40, Denham, the A40 and Denham Green would run to the east of the Denham Aerodrome.

Along this stretch, the alignment would pass beneath some significant hills. These would increase the cover to the tunnel from the minimal levels present at the station locations to between 40m and 50m. The tunnel could be lifted where there is increased cover to reduce the depth of the shafts connecting the tunnels to the surface.

Immediately to the south of Denham the alignment would start to turn in a western direction. The pair of tunnels (Up and Down) would start to diverge from each other, increasing the distance between the tunnels from around 10m to 200m. They would also start to rise at a gradient of approximately 1% to allow them to surface at two portals adjacent to Route 3. The distance from where the tunnels start to diverge to where they become a surface alignment at the tunnel portals is 4.9km. The divergence is necessary to achieve a suitable alignment at the tunnel portal for the turnouts to connect to Route 3 whilst maintaining a line speed of 230kph through the junction.

both tunnel portals for the Heathrow loop would be located to the south side of Route 3 west of the River colne valley and east of the tunnel beneath the m25 northeast of chalfont St Peter. The tunnel portals would be approximately 15m below the level of the route. At the tunnel portal location the Up main would be immediately adjacent to the route, with the Down main portal

further to the south. Immediately upon surfacing, and whilst still at a level below the route, the Up main would pass beneath the twin route tracks in a grade separated junction.

From the tunnel portal both of the loop alignments would continue to rise to bring the track to the same level as Route 3 and with 225kph turnouts.

The vertical and horizontal alignment would require modification to Route 3 about 200m from the tunnel portal. The tunnel would need to be widened to allow the switches. This could be achieved by either constructing a length of ScL tunnel prior to the start of the bored tunnel, or by breaking out the initial 200m of the bored tunnel to the necessary size and constructing a ScL tunnel from this.

It is envisaged that this junction could be refined during the detailed design with lesser Route 3 modifications. Having this connection completely on the surface would facilitate long term maintenance access.

Sub-surface Option8.9.6.

An alternative to that described above would be to have a tunnelled connection from the Heathrow loops to Route 3. This would be 0.5km shorter.

Similar to the alignment described above, the loops through each of the stations options would recombine at a location to the north of Iver and then follow a common alignment to the connection point to Route 3. This would initially comprise a straight, northerly tunnelled alignment running to the west of the m25, and crossing beneath it to the north-east of Iver Heath. The alignment would continue in the same direction and having passed beneath the m40 and the A40, would run under Denham Golf club and the Aerodrome to the west of Denham. At the northern end of this straight, the alignment would lie half a kilometer to the west of that for the surface connection.

As with the surface connection alignment, the alignment would pass beneath some significant

219

hills along this stretch,. These would increase the cover to the tunnel from the minimal levels present at the station locations to between 40m and 50m. It was again assumed that the tunnel would maintain a constant gradient along this length.

To the north of Denham Aerodrome, the alignment would start to turn in a western direction to align with the Route 3. The tunnelled alignment would pass beneath the m25 at a location approximately 200m south of where the tunnel from Route 3 would cross. At a point to the north-east of chalfont St Peter, the alignment of the loop from the Heathrow stations would meet Route 3 and there would be a junction at this location. The junction geometry would allow 225kph turnouts to be utilised.

At the junction location of the tunnels, the rail level would be approximately 35m below ground level in a mined cavern. The geology at this location is chalk, and the construction methodology envisaged is that the Route 3 tunnels would be installed first. The bored tunnels would be widened out and the widened cavern used to serve as the terminating point of the connecting tunnels to Heathrow. The caverns would be 300m long with a maximum width at rail level of 22m. The exact design of the caverns would depend on the tunnel design for both the Route 3 and Heathrow tunnels. The connection would require very different individual alignments should Route 3 tunnel be a single bore tunnel rather than twin bores.

The area above the cavern location comprises agricultural fields and minor roads.

This option is non-preferred by HS2 due to the construction and operational risks associated with having the switches and turnouts in deep caverns.


SPur DESIGn from routE 38.10.

There would be a triangular delta junction on Route 3, with grade-separation of the junctions on the through route. The south-facing point of the delta junction would also be grade-separated. Southwards, the spur would continue to a 4-platform terminal station at T5, T6 or Iver.

The spurs would be twin 7.25m ID tunnels with cross-passages. Intervention shafts would be included at intervals of approximately 2km. In some locations the shafts and their associated hard-standing for maintenance and emergency vehicles would necessitate local modifications to roads or the provision of access from adjacent roads.

Eastern Leg of Delta junction8.10.1.

The eastern connection point of the spur to Route 3 would be in the Northolt area, with the tunnel portal for the twin tracks to Heathrow being located immediately to the east of the Hillingdon Waste Transfer Station. There would be a grade separated junction, designed to maintain a line speed of 225kph on the spur.

The siting of the tunnel portal requires consideration of a number of factors, of which the key ones are described below. The Northolt tunnel portal location was chosen to achieve a balance of these.

to minimise the length to each of the •

Heathrow station locations to minimise the journey time and the construction cost.

to allow a suitable track geometry which •

would maintain high speed through the turnout and on the route to Heathrow. If the turnout were located to the west of Northolt the radius of curvature on the bend to T6 and Iver would restrict the operating speed to less than 225kph.

Availability of space to allow the •

branch off from Route 3.

The grade-separated junction. This would •

require a greater width of rail corridor than necessary for the through HS lines. It

was therefore necessary to find a location where this additional width of corridor can be accommodated with least impact on adjacent landowners and users. Suitable open ground to allow the necessary deep cutting for the southern point of the delta junction. At this location the east and western leg of the delta junction join, and a deep grade separated junction would be required. This would necessitate a significant area of open ground, and needs to be in a location which matches the alignment geometry of both the eastern and western leg.

The tunnel portal would be located to the north of Route 3, and the tunnels would swing to the south to pass under the through HS lines. The alignment would then pass beneath South Ruislip, Northolt Aerodrome and the A40 whilst swinging around to the south. Approximately 200m to the south of the A40, the tunnels would enter an open cutting to allow connection of both of the sides of the delta junction from London and the West midlands to the twin lines down to the Heathrow station locations.

The tunnel alignment from the Northolt portal to the connection cutting would generally provide at least 20m cover from the crown of the bored tunnel to the ground surface. The vertical alignment design was based on keeping the tunnels as shallow as practical, but the depth of cover could be increased by lowering the vertical alignment. The horizontal alignment would result in a line speed of 200kph through this section.

Western Leg of Delta junction8.10.2.

The western connection point of the spur to Route 3 would be to the west of West Ruislip with the tunnel portal for the twin tracks to Heathrow being located 700m to the west of breakspear Road South. There would be a grade separated junction, at a line speed of 230kph on the spur. The turnouts would extend back onto the viaduct over the colne valley at this location.

The tunnel portal would be located to the north of Route 3, and once the tunnels had started these would swing round to the south and cross under

221

the through HS lines. The alignment would then pass beneath West Ruislip, Northolt Aerodrome and the A40 whilst swinging around to the south. Approximately 200m to the south of the A40, the tunnels would enter an open cutting to allow connection of both of the sides of the delta junction from London and the West midlands to the twin lines down to the Heathrow station locations.

The tunnel alignment from the Northolt portal to the connection cutting would generally provide at least 20m cover. The vertical alignment design was based on keeping the tunnels as shallow as is practical, but the depth of cover could be increased by lowering the vertical alignment. The horizontal alignment would result in a line speed of 225kph through this section.

Delta junction Connection Cutting8.10.3.

The pair of tunnels from the London side of the delta junction and the pair of tunnels from the West midlands side would join at a grade-separated juntion within a long cutting that all four tunnels would enter. A single pair of tunnels to Heathrow would start at the southern end of the cutting. The cutting would extend 30m below the existing ground level.

The elevation of the tunnels could be optimised to facilitate the necessary grade separated junctions. It would also be possible for the approaching tunnels to cross over each other resulting the pair of Southbound lines being adjacent upon entry into the cutting. This would result in a shorter excavation, but more complicated tunnel alignments. The feasibility of this would depend on any sub-surface constraints to the tunnel alignments under Northolt Aerodrome and on the speed at which the trains are running in the tunnels; faster speeds would result in less scope to significantly change vertical and horizontal alignments.

The cutting would comprise battered slopes, with vehicular access from the A40 for future access and maintenance. As the location of the cutting

extends across the existing route of the Yeading brook this would need to be diverted to a new alignment.

constructing this junction in an open cutting would facilitate future access for maintenance and renewal of the switches and turnouts. It would also reduce the construction risk associated with constructing this as a tunnelled connection. In this location the geology comprises London clay, and as such there would be significant settlement risks should a large sub-surface cavern be excavated to allow the necessary interconnections. It would also create logistical issues with tunnel boring machines, with additional shafts being needed to remove the secondary drive Tbms once they had connected to the through drives. by constructing an open cutting, this could be used to drive Tbms on both the east and west legs of the delta junction and towards Heathrow.

Delta junction Connection Cutting to 8.10.4.

Heathrow T5

South of the delta junction, the route would follow a straight line through Hayes End prior to swinging west to pass beneath West Drayton. It would pass under the m4 immediately to the east of its junction with the m25, and continue under Harmondsworth moor.

The twin bored tunnel alignment from the connection cutting would generally provide at least 20m cover. The vertical alignment was based on keeping the tunnels as shallow as practical, but the depth of cover could be increased by lowering the vertical alignment.

The horizontal alignment of the tunnels from the cutting to the south side of Harmondsworth moor would allow trains to run at 225kph. At the southern side of Harmondsworth moor, a curve would be required to allow the alignment to swing around into the T5 station location, and this would limit speeds to 180kph. As this curve is near the station, and trains would either be already braking or still accelerating at this point, the impact on journey times would be minimal.


Having passed beneath the colnbrook by-pass at the south side of Harmondsworth moor, the vertical alignment would start to rise. At 15m cover, the bored tunnels would stop, and the continuation to T5 would be in a cut-and-cover tunnel. The cut-and-cover tunnel would necessitate the rebuilding of both bath Road and the spur from the m25 to Heathrow. The design assumed that these bridges would be demolished and replaced by an off-line structure to minimise traffic disruption.

Along the length from the colnbrook bypass to the T5 station, the cut-and-cover tunnel would run through an extensive flood plain. The impacts of this on the construction during construction would need to be ascertained and mitigated as necessary as part of the environmental works.

Delta junction Connection Cutting to 8.10.5.

Heathrow T6

South of the Delta junction, the route would follow a straight line through Hayes End prior to swinging south to pass beneath West Drayton. It would pass under the m4 between the junction with the m25 and Stockley Road.

The twin bored tunnel alignment from the connection cutting would generally provide at least 25m cover. The vertical alignment was based on keeping the tunnels as shallow as practical, but the depth of cover could be increased by lowering the vertical alignment if necessary.

The crossing beneath the m4 could potentially require modifications to the vertical alignment. The m4 runs in a cutting at this location, and there would be approximately 8m from the proposed tunnel to the road level. Accurate site information would be required to determine the level of the ground, and the design checked against this. If the clearance between the crown of the tunnel and the road formation were predicted to result in undue subsidence risks, the alignment would need to be lowered. This would necessitate steeper gradients on the approach to the station as the close proximity of the station to the m4 reduces scope for other solutions.

The bored tunnels would end to the north of Harmondsworth Lane, and the continuation to the station box would be in cut-and-cover tunnel, necessitating the rebuilding Harmondsworth Lane.

The horizontal alignment of the tunnel from the cutting to the T6 station location would allow trains to run at 225kph.

Delta junction Connection Cutting to Iver8.10.6.

South of the Delta junction, the twin bored tunnel alignment would follow a straight line through Hayes End prior to swinging west to pass beneath Yiewsley and on to the Iver location.

The Iver station would place the lines at approximately ground level. This could be constructed at a lower level through use of a cut-and-cover box. This would result in increased cost, and complicate the passenger movements for people transferring between HS2 and the Great Western main Line. The impacts of the latter could be partially mitigated through the design of the station, and this would need to be considered further as the design was progressed.

The ground level station would require the tunnelled alignments to rise up to a tunnel portal to the east of the station. between the station and the tunnel portal, the alignment would be contained in a structurally retained cutting.

At the Iver location, there are extensive flooded gravel pits and the River colne. The Grand Union canal, and areas of residential and industrial property. The alignment was designed to minimise the impact on these constraints, and remained in tunnel until immediately to the west of the River colne. At this point, the tunnel portal would be sited.

In order to be able to achieve necessary reduction in level from the station to the tunnel portal within the available space, the alignment would need to have a gradient of 3.5%, the maximum permitted by the project specification. It would also require the radius of curvature on the vertical curves to be reduced to the minimum permitted. This alignment is therefore at the limit

223

of its design and it would be important to verify the constraints prior to further design. This would include ascertaining the depth of the river and gravel pits to ensure that sufficient cover would be present from the top of the tunnels to the bottom of these bodies.

construction of the approach to the tunnel portals would possibly be in saturated ground conditions beneath the water table. Whilst feasible to construct in these conditions, extensive dewatering would be required.

The horizontal alignment of the tunnel from the cutting to the Iver station location would allow trains to run at 225kph throughout.

SErvInG HEatHrow from routE 2.58.11.

Each of the Heathrow station options which were served from Route 3 would be able to be served from Route 2.5.

There would be no significant difference to the design of the spur options as the connection to the route at both Northolt and West Ruislip would be similar. The junction would be in the same place for the Northolt branch in a very similar location for the West Ruislip portal. The vertical alignment design would be very similar. The similarities in the design would result in the spur option costs from Route 2.5 being the same as on Route 3.

The eastern side of the loop to Route 2.5 would be tunnelled. This is due to the presence of Iver and Gerrards cross, significant roads (including the m25, m4 and m40), railways and canals, protected environmental features, and topography comprising steep sided hills and valleys. In the vicinity of the junction of the m25 and the m40, the connection to Route 2.5 would progressively swing to the west, and pass beneath Gerrards cross. The connection to Route 2.5 would be to the West of Gerrards cross.

Route 2.5 would pass in tunnel beneath Gerrards cross with a portal immediately to the west. The connection of the loop to Heathrow could also

have its tunnel portal at this location, adjacent to that of Route 2.5.

There were two junction options to connect the Heathrow loop to Route 2.5;

Placing the tunnel portals to Heathrow •

on either side of the main route portals, which would avoid the need for a grade separated junction on the surface. Once the route and Heathrow loop were in tunnel, the northern Heathrow tunnel would swing under the main route, and run adjacent to the southern tunnel to Heathrow.

A grade-separated junction as part of the •

surface alignment. This would result in the pair of tunnels to Heathrow being on the southern side of the main route and would avoid the need for the tunnels to cross.

The optimal junction design would depend on the horizontal and vertical alignment of the main route.

SErvInG HEatHrow from routE 48.12.

Due to the northerly alignment of Route 4 from Old Oak common, it would not be feasible to connect this alignment with a loop or spur to Heathrow. The interconnectivity with Heathrow would therefore need to occur at Old Oak common.


Connection Length (Km) base Construction Cost

Heathrow Terminal 5 loop 33.70 3,068,661,998

Heathrow Terminal 5 spur 22.03 1,748,145,375

Heathrow Terminal 6 loop (from Northolt) 29.86 2,659,885,404

Heathrow Terminal 6 loop (from Old Oak common) 33.70 3,081,814,600

Heathrow Terminal 6 spur 19.68 1,446,211,405

Iver loop (tunnelled connection to Route 3) 25.15 2,097,875,162

Iver spur 18.93 1,357,781,416

Iver loop (surface connection to Route 3) 24.40 1,745,492,378

CaPItal CoSt of HEatHrow oPtIonS8.13.

The capital cost of the options for connecting Heathrow are presented in the table below.

journEy tImES vIa HEatHrow8.14.

These timings are for a through route via Heathrow (and route 3 thereafter)

Timing Points Stops Route 2.5

London to birmingham Old Oak common, Heathrow, birmingham Interchange

59m 56s

London to birmingham Heathrow, birmingham Interchange

57m 13s

In comparison with the Route 3, the journey time would be about 9 minutes slower than an equivalent “ two intermediate stops” timing.

225


tHE InCrEmEntal naturE of tHE StuDy9.1.

The Government’s brief to HS2 Ltd required the consideration of options for connecting HS2 to HS1. Three options were prepared for this link:

Option 1: a single track bi-directional link •

via NLL to the portal north of St Pancras;

Option 2: a double track link via the NLL •

to the portal north of St Pancras;

Option 3: a double track ‘fast’ link •

to a new grade-separated junction east of the St Pancras portal.

This report addresses these options as incremental additions to Route 3.

An option to connect HS1 below ground between St. Pancras and Rainham were considered impractical, as a high-speed, tunnelled, grade-separated underground junction in an operational high-speed railway would be required.

An option to connect at the Stratford box was rejected as impracticable because of the proximity of the Olympic Power Lines Upgrade (PLUG) tunnels.

oPtIon 19.2.

This option would provide a single Gc gauge track from Old Oak common to the existing grade-separated junction from the North London Line (NLL) to the St Pancras portal.

The single track would leave Old Oak common station via a central tunnel to camden Junction where a new portal would be constructed immediately south of slewed NLL lines. The Old Oak common station layout would be adapted to create a non-conflicted junction.

From camden Junction, the bi-directional Gc link would occupy the southern line across the camden viaducts through camden market. The proposed NLL scheme would be modified from camden Station to the link chord by building a third track to the north of the existing two tracks (together with bridges) which would serve a new platform edge at camden Station. Platform

1 at camden Station would be taken out of commission to provide the bi-directional line with Gc gauge and the three bridges east of the station rebuilt.

The HS2 track would follow the existing link to the junction at the tunnel portal immediately north of St Pancras.

OPTIONS FOR THE HS1 TO HS2 cONNEcTION9.

227

WESTMINSTER

HENDON

LAMBETH

HORNSEY

CHELSEA

WILLESDEN

HAMPSTEAD


KENSINGTON

KENSAL TOWN

HAMMERSMITH

CAMDEN TOWN

Proposed Route

Tunnel

Viaduct


Connection to HS1 - Option 1

Tunnel

Above Ground

HS1 Portal

0 0.6 1.20.3Km

OPTION 1- HS1 cONNEcTION


oPtIon 29.3.

This option would provide two tracks at Gc gauge connecting Old Oak common to the existing grade-separated junction at the portal north of St Pancras.

Old Oak common station layout would be modified to create effective non-conflicting junctions with two dedicated link tunnels leaving the box and emerging immediately west of the disused Primrose Hill Station, at which point an elevated grade separation would be achieved. This option would minimise new tunnelled lengths, and make maximum use of Primrose Hill Tunnels.

A two-track Gc-gauge route would then be provided through Primrose Hill Tunnels (major widening works to part of the Stephenson Tunnel) and then a further grade separation in the camden Junction area to facilitate a twin-track, Gc, elevated route through camden market. (The viaduct would need extensions for new walkways.)

The NLL proposals would be modified such that both NLL tracks would occupy the vacant track beds to the north of the existing from west of camden Road Station to the St Pancras portal zone. This would necessitate building three new bridges and two new platforms at camden Station.

The HS2 tracks would follow the existing NLL to the existing grade-separated junction north of St Pancras which has provision for twinning. This would require decommissioning of two platforms at camden Station, construction of a larger junction west of camden Station and reconstruction of three bridges east of camden Station.

The line speed associated with this option is approximately 60kph. However, it does not reduce significantly line capacity through the camden market Zone as Option 1.

229

WESTMINSTER

HENDON

LAMBETH

HORNSEY

CHELSEA

WILLESDEN

HAMPSTEAD


KENSINGTON

KENSAL TOWN

HAMMERSMITH

CAMDEN TOWN

Proposed Route

Tunnel

Viaduct



Tunnel

Above Ground

HS1 Portal

0 0.6 1.20.3Km



oPtIon 39.4.

This solution would provide a twin-track fast connection from Old Oak common to a new portal in the Rainham area (29km of tunnel). Old Oak common Station would be modified to provide a non-conflict junction as Option 2.

An assessment of an alternative junction at Stratford box was carried out, which would reduce the tunnel length by approximately 13km. This would be achieved by bringing the HS2 tunnels up through the floor of the cut-and-cover box. However, this would not be feasible as:

Tunnel Reception chamber. The proposed •

northern track alignment for the HS2 would clash with the foundations for the Temple mills connection. This may be avoided if the sideways slew was tighter than 1 in 20 but this could not accommodate the required line speed. Hence the northern track could not work from this point. An alternative to slew the northern track to the south would also not work as it would still clash with the Temple mills foundations.

Tunnel clearances. To construct the •

new tunnels the following clearances would be required due to the ground movements associated with settlements:

Horizontal clearance = 9m –

Vertical clearance 4.5m –

Hence with an excavated face of 9m the –

tunnel space proofing dimensions are:

Horizontal = 27m (3 x 9m) –

Vertical = 18m (2 x 4.5m + 9m) –

At the west end of the Stratford box the ‘Plug’ tunnels pass below the box. The crown of these tunnels is approx -20mOD, and the box base slab SSL is approx -10mOD. Hence there is only a 10m gap for the HS2 tunnels to pass over the Plug tunnels and below the box base slab. This would be impracticably tight.

CaPItal CoSt of tHE HS1 ConnECtIon 9.5.

The capital cost of the options for connecting to HS1 are presented below.

Option 1 = £457,730,400•

Option 2 = £812,165,920•

Option 3 = £3,595,290,000•

231

ACTON

BECKENHAM

CHINGFORD

BOREHAMWOOD

BOW

CHESHUNT

CROYDON

EDGWARE

ENFIELD

LEWISHAM

RICHMOND

STEPNEY

STRATFORD

WALTHAMABBEY

WALTHAMSTOW

WEMBLEY HAMPSTEAD

PADDINGTON

HAMMERSMITH LAMBETH

ST ALBANS

WOOLWICH

BROMLEY

COULSDON

CRAYFORD

DAGENHAMEAST HAM

EPPING

EPSOM

ERITHGREENWICH

HATFIELD

ILFORD

KINGSTONUPON THAMES

LEATHERHEAD

LOUGHTON

ORPINGTON

SWANSCOMBE

Proposed Route

Tunnel

Viaduct



Tunnel

HS1 Portal

0 1 20.5Km



tHE StaGE 3 ProCESS10.1.

between July 2009 and September 2009, a number of other options were studied. These were developed to a lesser degree of engineering detail than Routes 3, 4 and 2.5 described above. Outline engineering schemes were developed to assess the viability of options under geotechnical and spatial criteria. These options were subject to appraisal by HS2 Ltd and were not pursued.

These options were:

London Station•

Deep ‘cavern’ Stations at Paddington –

Kings cross Lands –

Euston (Options 1 and 2) –

Line of Route•

m1 corridor (Hemel Hempstead –

to Edlesborough)

Route 2 (chiltern Line corridor) –

Route 1 m40 (Denham to Aynho) –

Gaydon to chipping Warden –

brackley to catesby –

West midlands•

On-line Widening: Lapworth to moor Street –

On-Line Widening: berkswell to birmingham –

birmingham Outer Eastern bypass –

birmingham Inner Eastern bypass –

birmingham moor Street East (Through) –

birmingham moor Street East Terminus –

birmingham New Street –

central birmingham to the North-West –

Heathrow Option•

Ealing broadway –

Southall. –

lonDon StatIon - DEEP ‘CavErn’ 10.2.

StatIonS at PaDDInGton

There were two options proposed for a 10-platform terminus at Paddington.

Option 1 A tunnelled station (cavern) •

beneath the footprint of the existing GWmL station terminus

Option 2 A tunnelled station (cavern) •

beneath the St. mary’s Hospital site which is believed ‘due for redevelopment’

The proposed station would be constrained by existing LUL tunnels, concourses, etc. and would be between 25m and 30m below ground level in the top of the Lambeth Group and primarily within the clay layer. This is a similar stratigraphy and depth to crossRail’s bond Street Station. The plan form of the station was based on sprayed concrete lining tunnelling technology with typical caverns up to 10m high and 12m across providing accommodation for one platform and one track in each.

caverns would be separated by access tunnels for escalators and through circulation and would, therefore, be at approximately 40m centres to minimise interaction during construction and ground movement. Even with this spacing it is anticipated that the ground movements of the order of 150mm would occur.

For listed historic buildings such as Paddington Station and the Train Shed, it is recommended that ground movements should not exceed 15mm which is considerably less than anticipated in this case.

The need to space caverns to address construction issues would make not only the station very wide (≈300m for 10 platforms), but the throat (track fan) would be extensive since the parallel platform tracks would be so widely spaced.

For Option 1, the site constraints would include the crossrail (cut and cover) station along Eastbourne Terrace, and the bakerloo Line which runs diagonally from south-east and north-west across the site at a depth of about 15m below concourse level.

OPTIONS STUDIED IN STAGE 310.

233

Bayswater

PADDINGTON


Possible Station Location0 0.10.05

Km

PADDINGTON STATION


For Option 2, the St mary’s site would be bounded by the basin along its north edge, bordering onto the new piled developments (arguably one could construct under the basin itself), and the bakerloo Line which again would cross the site.

There are also modern buildings on the St mary’s site which are piled and are not due for demolition which, if retained, would act as a major constraint for this option.

lonDon StatIon - kInGS CroSS lanDS10.3.

Two options were proposed:

A ten-platform terminus station constructed •

within a deep cut-and-cover box

A ten-platform terminus station •

in tunnel (cavern)

In both cases, the level of track formation would possibly be about 35m below ground level. This would create challenges for both cut-and-cover and tunnelled construction.

The site is bounded by major infrastructure projects as follows:-

to the west, the elevated St Pancras •

International Station with throat and track veering across the north of the site into the tunnel portal;

to the north, in addition to the at-grade •

tracks for HS1, there is the North London Line on embankment and the Thameslink lies at approximately 12m below ground. This would effectively block all but a deep tunnelled station exit to the north;

to the east, there are the gasworks •

tunnels serving Kings cross and the Piccadilly Line tunnels;

to the south is the Thames Water Ring •

main (about 25m below ground) and the new LUL concourse and service yard.

These constraints would act to ‘park’ the extensive spatial requirements for a tunnelled

(cavern) terminus station (approximate width required 300m for a 10-platform station).

There are a number of existed listed or locally protected structures together with plans for numerous new developments (planning granted). These include:

the listed Granary Shed – under conversion •

for the central St. martin’s Art college;

the Regent’s canal and basin;•

camden Nature Park;•

Fish and coal Office buildings;•

camden Sewer;•

New building for Sainsbury (committed)•

The extensive redevelopment also includes pile structures with piles of the order of 25m long (also an obstruction for any tunnelled option).

The construction of Option 1 cut-and-cover would require a jacked structure or similar beneath the canal, demolition and reconstruction of any listed building to be retained and diversion of the camden Sewer. Although the extreme depth of the cut-and-cover creates major challenges for the construction, these ground conditions can be overcome.

The construction of option 2 (cavern) would require tunnelling in the Lambeth swamp which are water bearing structures. This could make sprayed concrete techniques impossible therefore this option was not carried forward.

235

Barnsbury

St Pancras



Km

KINGS cROSS STATION


lonDon StatIon – EuSton (oPtIonS 1 10.4.

anD 2)

The chosen Euston Station option was originally called “Euston Option 3”. This section of the report addresses the other two options not taken forward. Option 3 was carried forward and has already been described.

Two permutations were developed:

Option 1: HS2 new 10-platform station •

built above existing station projecting in plan between the existing office buildings up to the gardens;

Option 2: HS2 new 10-platform station •

at grade with displaced ‘classic’ platforms built at high level.

Option 1 would locate the new HS2 station above the existing ‘classic’ station, with the 10 platforms (5 islands) projecting between the two office buildings to the south of the station to provide the platform length required. The concourse would be sited between the two deck levels. The new platform deck would be located approximately 20m above the existing track level to enable the throat and approach tracks to pass over Hampstead Road bridge. The tracks would then descend north to a point under Park Road on the easterly side.

This option would appear to minimise disruption to the existing station, but the construction of the support structure for the elevated platform deck and the track fan would necessitate reconstruction of most of the classic station below together with the London Underground concourse. Preliminary studies of alignment indicated that the site constraints would severely compromise the throat geometry, limiting operational movements, requiring ‘special’ switches and placing the throat on an incline. In addition, the tunnel portal width cannot be accommodated east of the existing WcmL tracks south of Park Road.

Option 2 would locate the new HS2 platforms below ground along the west side of the station, with classic services on an elevated

deck above. The concourse would be sited between the two deck levels. The increased HS2 gauge would require the deck level to be lowered approximately 1.5m to pass beneath the Hampstead Road bridge. The classic station would be about 23m above HS2. The elevated throat would pass over Hampstead Road bridge and then the tracks would descend immediately above the new HS2 tracks to the existing tunnels beneath Park Road west of the 4-track classic tunnel. As in Option 1, the construction of the lengthened HS2 platforms and the elevated deck structure would realistically require the demolition and reconstruction of both the existing station and London Underground concourse below. The new LUL ticket hall would be sited below the train deck level. It would be larger to handle the increased number of passengers from HS2, and would double the escalator access facilities to all three LUL lines (Northern charing cross, Northern city, Victoria).

Preliminary studies of alignment for this option indicated that provision of a vertical throat for HS2 would be compromised by the need to achieve two tiers of tunnel portal (one for HS2 and one for classic services). In both options, the location of an upper platform level effectively precludes any east-west permeability except in the Hampstead Road area. Also, in both cases, there would be a requirement for additional land to be acquired immediately north of the station at Hampstead Road to enable the HS track fan to be developed along its west side, together with the demolition of Grantley Road bridge and mornington Street bridge due to insufficient clearance.

Preliminary consideration was given on practicalities of construction and how much of Euston Station could reasonably be kept open during construction of both Options 1 and 2.

The construction would probably be carried out in two phases, necessitating the closure of half the existing station; this would lead to the potential loss of 8 platforms during the works.

237

Bloomsbury

Somers Town



Km

EUSTON STATION


lInE of routE - m1 CorrIDor (HEmEl 10.5.

HEmPStEaD to EDlESBorouGH)

The start of this route was assumed to be Euston, with an identical alignment to Route 3 to Old Oak common, with a tunnel from Old Oak common towards Elstree. The route would then veer to the east towards Junction 5 of the m1 at Aldenham, with a tunnel portal situated immediately to the north of Junction 5.

The route would follow a surface alignment across the River colne valley in a combination of cuttings on the approaches to the tunnel portals, embankment and viaducts. The alignment would be parallel and to the east of the m1, to a new tunnel portal on the southern side of bricket Wood common. Once in tunnel, the HS alignment would trend northwest and run under Garston prior to emerging at a tunnel portal by Junction 6 of the m1.

To the north of this tunnel portal, the alignment would remain on the surface to the west of the m1. It would cross m25 on a viaduct, and continue in a straight alignment to the east of Hemel Hempstead. North of Hemel Hempstead, the alignment would bend to the west and continue to run across country, predominantly on agricultural land. Along this length the alignment would be chosen to minimise the quantity of woodland affected but there were few significant environmental constraints.

The route would then pass south of Jockey End, and drop down the side of the valley to the River Gade and along the bottom of the valley, rather passing through the edge of the escarpment. This would avoid tunnels from this section, and a general reduction in the gradients on the vertical profile which should improve the speed achieved on the line.

The end of this route would be to the south of Leighton buzzard, where it would adopt the Route 4 alignment. The alignment from Edlesborough to Leighton buzzard would generally be across agricultural land, with a viaduct used to cross the Grand Union canal.

239

ST ALBANS

TRING

LUTON

HAYES

PINNER

MARLOW

KENTONHARROW

EALING

BUSHEY

WEMBLEY

WATFORD

RUISLIP

RADLETT

HITCHIN

EDGWARE

CHESHAM

WENDOVER

UXBRIDGE

STANMORE

NORTHOLT

AMERSHAM

NORTHWOOD

HARPENDEN

GREENFORD

DUNSTABLE

MAIDENHEAD

HILLINGDON

CHORLEYWOODBOREHAMWOOD

BERKHAMSTED

HIGH WYCOMBE

BEACONSFIELD

RICKMANSWORTH

HOUGHTON REGIS

GERRARDS CROSS

HEMEL HEMPSTEAD

LEIGHTON BUZZARD


Route0 52.5

Km

m1 cORRIDOR


lInE of routE - routE 2 (CHIltErn lInE 10.6.

CorrIDor)

This route would be identical to Route 3 between Euston and West Ruislip.

Ruislip Gardens to Denham10.6.1.

The “on-line widening” would continue from the LUL works at Ruislip Gardens Station heading north to cross the Grand Union canal making its way to Higher Denham.

From Ruislip Gardens to the Grand Union canal, the route would traverse an area relatively free of urban development, apart from around West Ruislip LUL Station.

As the alignment approaches Denham, it would cross the Grand Union canal, over which a viaduct would be required. To Denham, the route would generally be on embankment, and a number of properties around the sports ground area and in Higher Denham would be impacted. As it leaves Higher Denham, it would dive down into a cutting to pass under the m25 and A413 and would approach a tunnel portal south of Gerrards cross.

Gerrards Cross to beaconsfield10.6.2.

Under Gerrards cross, the route would change to the southerly side of the existing railway, and would near Raylands Farm. It could potentially impact the River misbourne and its associated flood plain. As the new route would emerge from Raylands Farm, to achieve a high speed, it would not follow the existing rail corridor but would follow a flatter radius and traverse a Golf course and a series of wooded areas (Pitlands, Walk, the mount) generally in cutting until the tunnel portal on the edge of beaconsfield.

beaconsfield to High Wycombe Tunnel10.6.3.

HS2 would be in tunnel from beaconsfield to High Wycombe.

High Wycombe to Ilmer10.6.4.

The route would emerge from tunnel at West Wycombe, near branch Wood and would then run to the north of the A4010 and bradenham.

The route would be tunnelled approximately 4 km. under Saunderton Lee and Horsenden. North of Saunderton Lee, it would emerge near Ilmer to adopt the Route 2.5 alignment.

Ilmer to Wootton underwood10.6.5.

The line would emerge out of tunnel just east of Ilmer and proceed to the west veering away from the chiltern line. Just before Haddenham, the route would start to diverge towards the chiltern line tracing along the surface topography. North of Haddenham, the alignment would follow the chiltern line with the majority of the route on elevated structure. North from Dorton, the alignment would run alongside the chiltern corridor and tunnel under the SSSI at Rushbed’s Wood and under the chiltern Line. The line would emerge out of tunnel north of Rushbed’s Wood.

Wootton underwood to aynho10.6.6.

The route would veer east away from the chiltern line to the eastern side of bicester. The line would come in close proximity to Launton and then cut through bicester airfield. It would avoid disturbing a disused quarry (now a SSSI). The topography north of bicester then starts to rise sharply and the route would pass through bainton. The line would diverge towards the m40 motorway to pass west of Stoke Lyne. The line would then pass to the western side of Souldern and west of Aynho Park and Garden.

aynho to Gaydon10.6.7.

The route would enter a 350m tunnel to the east of Aynho. It would then cross the chiltern line, the Oxford canal, the River cherwell and its associated flood plains; it would be on a continuous viaduct. The line would then follow the m40 motorway corridor to the east of banbury; as a consequence of this the speed would reduce in steps to 300kph.

The route northwards from banbury would return to 400kph, and would avoid the settlements of Little bourton, mollington and the Farnborough

National Park and Garden. The line would then cross over to the western side of the m40

241

OXFORD

COVENTRY


Route0 105

Km

ROUTE 2


motorway at Avon Dassett, in order to avoid the hilly terrain of the burton Dassett Hills. The line would then pass between the motorway and Temple Herdewyke and run towards the east of Gaydon.

Gaydon to Warwick to Dorridge10.6.8.

The line would pass in close proximity to the west of Kingston Grange, and pass through chesterton Wood. The route would then pass through one of the buildings at the m40 Warwick motorway Service Area.

West of Debden Hollow and south of Warwick, the area is complex, with a major motorway junction, trunk and local roads, and the River Avon valley. There would essentially two design solutions: an elevated structure over all the obstructions, or a tunnel, probably in cut-and-cover. It would emerge out of tunnel on the east side of the motorway just west of Hampton on the Hill. North of Warwick and Hampton-on-the-Hill, there would be two main options:

towards central birmingham via Lapworth and •

a widened existing corridor via Dorridge;

towards birmingham international / NEc area.•

Warwick to birmingham International 10.6.9.

The speed would veer away from the m40 in order to avoid Little Shrewley as well as the Hatton railway junction. The line would avoid Wroxall Abbey National Park and Garden, then pass to the east of a Temple balsall, and around barston, balsall common and Hampton in Arden. It would then join the previously-described Route 3.

243


lInE of routE - routE 1 m40 (DEnHam to 10.7.

aynHo)

Denham to Hedgerley10.7.1.

This route would be identical to Route 2, Route 2.5 and Route 3 to Denham. At Higher Denham, it would dive into a cutting to approach the Gerrards cross tunnel portal. It would stay in tunnel under these areas for approximately 7 kms emerging at Hedgerley

Hedgerley to frieth 10.7.2.

From the tunnel portal at Hedgerley, the route would head north west to Wooburn generally crossing a wooded landscape and traversing two areas requiring viaducts, most notably at Wooburn, where a viaduct up to 40+m height could be required.

The route would continue to head north-west towards Frackwell Heath, requiring a mixture of short tunnels and viaducts. beyond Frackwell Heath, the route would require a long tunnel close to Handy cross Farm, and then a viaduct towards claymoor Park and Frieth.

frieth to aston Rowant10.7.3.

This area of the route is very challenging and undulating, and would require a significant number of large viaducts and tunnels to achieve the required line speed.

aston Rowant to boarstall10.7.4.

The line at this point would exit a tunnel through the chilterns, and run down into relatively flat land. The route would lie to the east of the m40 motorway and would avoid the villages of Postcombe and Tetsworth. North of Tetsworth, the line would veer away from the m40 and pass in close proximity to the west of Rycote Park. The route could not follow the sinuous alignment of the m40 in this area.

The line would then head towards Ickford on a viaduct over the River Thames and its tributaries. The route would then diverge towards the m40 motorway to pass east of Worminghall and would cut straight through the disused World War II

RAF Oakley airbase. The line would head west of Oakley whilst remaining on the eastern side of the m40; it would pass to the west of boarstall avoiding the site of a medieval village and would cross over the Dane brook.

boarstall to aynho10.7.5.

North of boarstall, the line would pass under Pans Hill in a 250m tunnel. The route would then veer away from the m40 motorway in order to avoid the villages of melton and Wendlebury. The line would then pass between Wendlebury and chesterton, through the chesterton Golf course and then over the m40. The alignment would pass to the west of middletone Stoney to avoid the middletone National crossing over of the Gagle brook, and it would then cut across the disused upper Heyford Airfield. It would then cross over the chiltern line. The route would pass to the west of Fritwell, then remain high to cross waterways and the m40, to pass to the west of Aynho Park and Garden.

At this locality, the route would adopt the previously-described Route 2 alignment.

245

OXFORD ST ALBANS


Route0 105

Km

ROUTE 1 - m40


lInE of routE - GayDon to CHIPPInG 10.8.

warDEn

The line would provide a link between the “Great central Line” to Kenilworth/coventry and the m40 Stokenchurch to Warwick Route. coming out of chipping Warden, the route would pass onto viaduct crossing a waterway. The alignment would then pass west of Wormleighton. The line would pass to the east of Fenny compton Wharf on a 1.5km viaduct, crossing over the A423 as well as the chiltern Railway. The route would then cross the m40 motorway and tie into the m40 Stokenchurch to Warwick Route at Gaydon.

247


Route0 21

Km

GAYDON TO cHIPPING WARDEN


lInE of routE - BraCklEy to CatESBy10.9.

The route would roughly follow a disused rail corridor, weaving through brackley, Turweston, Radstone, Helmdon, Eydon, moreton Pinkey, Woodford Halse and charwelton. It would pass between brackley and Turweston following alongside the A43 eventually crossing it as well as the Great Ouse. The route would pass to the east of Radstone, and before Helmdon, would enter a tunnel to avoid effects on an old railway cutting which has been designated a SSSI.

The line would exit the tunnel and climb towards Helmdon. The surface topography then becomes more challenging, which results in the alignment needing to enter a series of cuttings and viaducts, crossing the River cherwell twice. The route would pass east of Woodford Halse and through charwelton using the disused railway corridor. The line would then tie into the milton Keynes/Daventry to Kenilworth/coventry Route at catesby.

249

BANBURY

DAVENTRY

BRACKLEY


Route0 2.51.25

Km

bRAcKLEY TO cATESbY


wESt mIDlanDS - on-lInE wIDEnInG: 10.10.

laPwortH to moor StrEEt

General form of Widening10.10.1.

The route was, in general, a former 4-track corridor, of which only 2 are currently used.

From Lapworth to Tyseley, the existing, used, pair of lines generally lies in the northerly part of the formation. It was therefore assumed that the vacant, southerly side would be used to accommodate HS2. In general, all existing overbridges would be demolished and rebuilt. Existing stations could largely remain unaffected, although facilities such as car parks could be adversely affected.

It might be more costly to construct the new south-side lines as the “chiltern Route” and permanently switch trains to the south side, and place HS2 on the north side. This would almost certainly be more costly in first-cost, but it might be an economic solution when TOc compensation is considered.

Lapworth to bentley Heath10.10.2.

Lapworth was the southernmost extent of the former 4-track scheme. Dorridge Station is used as a turnback facility for terminating local services from the birmingham moor Street direction. mill Lane crosses the existing 2-track railway at bentley Heath Level crossing, and it was assumed that it would be unacceptable for this to remain. It was therefore assumed that there would be a “Dorridge bypass” picking up from the general m40 corridor to the m42 area.

M42 / bentley Heath to Widney Manor10.10.3.

From the m42 to Widney manor, there has been a complex history of track positions by virtue of the simplification of the railway and the construction of the m42. It would be proposed to locate the HS2 lines on the western side, which would involve a new structure over the m42, to its west. At Widney manor station, the existing car park would be replaced.

Widney Manor to Solihull Station10.10.4.

between these locations, the new tracks would lie to the south-west side. Various bridges would need to be extended and strengthened. At Solihull station, the HS2 tracks would pass to the west through the redundant platforms.

Solihull Station to acocks Green Station10.10.5.

Various overbridges would be demolished and replaced, sometimes requiring a closure, at others by using a temporary diversion, or a permanent off-line re-alignment. At Olton Station, the disused platforms would be demolished, and a new HS2 alignment placed on the abandoned formation.

acocks Green Station / Sherborne Road10.10.6.

At Acocks Green Station, the existing station car park would be abandoned to make way for the HS2 tracks. At Sherborne Road (which carries the station buildings), it might be possible to lower the HS2 tracks instead of raising the bridge.

acocks Green to Tyseley10.10.7.

Immediately north of Acocks Green, the existing tracks lie to the north of the formation, but towards Stocksfield Road, there has been a recent realignment of the railway to improve speeds in the Tyseley area, and to simply Tyseley South Junction. In this area, HS2 would need to swing from the southerly to the northerly side, in order to avoid Tyseley South junction, and to avoid interference with the depot.

An underpass would be constructed to bring the HS2 tracks to the north side. At Stocksfield Road bridge, an off-line temporary diversion and structure could be built, and the existing bridge re-configured to incorporate the underpass walls and slab.

Northwards from Tyseley, HS2 would lie on the northerly side and come out of the dive-under on the north of the existing railway. At Small Heath Station, the existing disused northern island platform would need to be removed.

251

BIRMINGHAM

WARWICK

SOLIHULL


Route0 2.51.25

Km

LAPWORTH TO mOOR STREET


bordesley Middleway / Camp Hill Line10.10.8.

There is a well-used connecting chord from the camp Hill line towards Tyseley, north of which the Dorridge Route crosses over bordesley middleway, and then the Grand Union canal.

If moor Street were to be a surface level terminal, or surface level through, station, HS2 would continue below ground level towards the camp Hill line then climb to pass over the canal and bordesley middleway, continuing on elevated structure to moor Street. If moor Street were to be a low-level through station, the alignment would remain deep all the way to moor Street.

253


BIrmInGHam outEr EaStErn ByPaSS10.11.

.As the on-line widening from berkswell to birmingham remains the second alternative for the birmingham approach behind the Water Orton corridor solution, this ‘Outer Eastern bypass’ solution also remains as the second alternative due to the impracticality of linking a north connection to the ‘Inner Eastern bypass’ solution from the berkswell to birmingham corridor.

burton Green to Coleshill10.11.1.

before reaching the m6 and m6 Toll Junction, the alignment would leave the route of the former Hampton Railway line before crossing the motorways. There was no obvious site to place a birmingham Interchange Station on this route.

Coleshill to belfry Golf Course10.11.2.

On the approach to Kingsbury, east of coleshill, a pinch point adjacent to Lea marston was identified where a potential HS alignment could cross the lakes and water park near Kingsbury. To avoid the village of Whitacre Heath, Shustoke Reservoirs and the SSSI of Whitacre Heath Nature Reserve, speeds would be restricted to 300kph. Part of maxstoke Park Golf course would be lost and the alignment would pass alongside the grounds of maxstoke castle.

On crossing the m42 north of Hams Hill Distribution Park, a series of reverse curves would avoid the grounds of belfry Golf course and the village of middleton.

north of belfry Golf Course10.11.3.

To join the West coast main Line north west of Tamworth, avoiding the village / towns of middleton, bangley and mile Oak, as well as Drayton manor Park and Hopwas Hays Wood, the location of any HS alignment was quite restricted. At the A5, a jacked box would be pushed under.

Connection into the WCML10.11.4.

The HS lines would connect to West coast main Line near Whittington.

birmingham International Delta Connection 10.11.5.

to Outer Route

A possible Delta solution was identified for the birmingham Outer Eastern bypass that would utilise the existing birmingham to coventry line through Hampton in Arden. No solution was considered realistic for the Inner Route or from the south of balsall common.

Water Orton Outer Delta junction10.11.6.

To link the birmingham Outer Eastern bypass with the Water Orton corridor into central birmingham, a Delta Junction was proposed east of Hams Hall Distribution Park with the north and south links passing either side of the park. All junctions with the mainline would be grade separated. The west junction connecting the north and south links would be a flat junction due to lesser traffic.

At Water Orton Station, the South link would continue to follow the existing lines to coleshill Parkway Station before diverging south east towards maxstoke castle. coleshill Parkway Station would need to be partially rebuilt.

The North link would pass over Water Orton Station. There may be scope pass under the m6 utilising one of the unused spans of the existing bridge. East of the m6, the route would avoid a large electrical distribution station before crossing over the m42 and birmingham & Fazeley canal, via a bridge, before joining the mainline adjacent to belfry Golf course.

255

LICHFIELD

BIRMINGHAM

TAMWORTH

SUTTON COLDFIELD


Route0 2.51.25

Km

bIRmINGHAm OUTER EASTERN bYPASS


BIrmInGHam InnEr EaStErn ByPaSS10.12.

This solution was selected as the preferred solution at Sift 3 and was since developed into the preferred Route 3. As the new proposal is significantly different from that described below, this option was subsequently replaced and not pursued. This route varied from Route 3 only north of middleton.

North of the belfry Golf course, the alignment would continue north-west towards m6 Toll to avoid higher ground below Whittington. The route would pass the site boundary of canwell Hall, skirting the Sand and Gravel Pit at moneymore and coach and Horses Plantations south of Weeford.

To avoid Lichfield and achieve a suitable crossing angle to connect into the West coast main Line, the alignment would head in a north-north-east direction. On reaching Lichfield, a viaduct would be required to cross a tributary of the coventry canal, WcmL and the A38.

The route would pass north of Streethay, crossing the A38 and its slip roads from the A5127. North of Streethay, the alignment would pass north of curborough and would avoid Tomhay Wood, before joining the WcmL.

257

COVENTRY

LICHFIELD

BIRMINGHAM

WALSALL

RUGELEY

TAMWORTH

SOLIHULL

NUNEATON

BEDWORTH

ALDRIDGE

SMETHWICK

KENILWORTH

BROWNHILLS

ATHERSTONE

SWADLINCOTE

SUTTON COLDFIELD

ASHBY-DE-LA-ZOUCH


Route0 42

Km

bIRmINGHAm INNER EASTERN bYPASS


wESt mIDlanDS StatIon - BIrmInGHam 10.13.

moor StrEEt EaSt (tHrouGH)

The station would be sited parallel to the existing moor Street Station along its north-east side. The station would provide two island platforms with associated stopping lanes in each direction separated by two fast through lanes.

The station would be formed in a cut-and-cover box approximately 1km long, 50m wide and up to 16m deep which would also provide the thrust block to start tunnelling machines in both directions.

This solution was developed in sufficient detail to allow a robust case to be made as to its unsuitability. HS2 Ltd felt that other options would be preferred

259

Digbeth



Km

bIRmINGHAm mOOR STREET EAST



moor StrEEt EaSt tErmInuS

The station would be fed from the south-east. There would be two island platforms (four platform edges). This station could only feed the chiltern corridor.

The station would run parallel to the existing moor Street on viaducts which clear the existing road infrastructure beneath. The tracks would terminate south-east of Park Street, leaving it intact for future traffic circulation. The concourse would be located at high level between the existing station and new development to the east, over the New Street and Snow Hill tunnels.

261

Digbeth



Km

bIRmINGHAm mOOR STREET EAST TERmINUS



nEw StrEEt

birmingham New Street Station was considered as a possible terminus for HS2 by undertaking major modification to the northernmost Platforms 1-5.

The proposed HS2 rolling stock would require an increase in the structural gauge to Gc, affecting both height and width. The tunnels to the east and the air-rights structure above give insufficient vertical clearance to the tracks.

There are shallow strip foundations, piled foundations supporting low and medium level buildings including the foundations to the high level Rotunda structure situated in close proximity to the tunnel. The new bull Ring is situated to the south of the tunnel. contiguous piled walls and bored piled walls located either side and between the existing East and West tunnels.

In order to allow HS2 trains to access New Street Station, the existing brick arched tunnel would need to be lowered by approximately 1.5m and widened to accommodate the HS2 rolling stock. The new tunnel profile would be a minimum of 8,900mm in width. This would involve the demolition of the existing tunnel and masonry piers as well the removal of overburden above the existing tunnels and to underside of roadway deck construction.

The tracks for HS2 and platforms would also have to be lowered to provide headroom beneath the concourses and shopping centre above.

The existing New Street station concourse substructure and foundations situated below the new lines would also need to be modified and/or strengthened or partially replaced to accommodate the track lowering. This would require the closure of parts of the station to accommodate the temporary works for the construction of bored piled retaining walls.

The existing station platforms would all be too short to support HS2 trains. Four options were considered, but all were considered to

compromise train length and future operations to an unacceptable extent.

Existing train services using these low-numbered platforms would be displaced. To provide for these displaced services, a new station would be required with up to 8 no platform edges up to 320m long trains. As a possible compensation, a route has been reserved by birmingham city council for a cross-city service in tunnel with a domestic two platform through station about 25m beneath New Street. This may compensate for the losses incurred providing for HS2. However, passenger demand forecasts indicate significant growth at New Street which was the driver both for the Gateway enhancements (mainly platform access) and the cross-city Studies.

Platform 1 could provide dedicated facilities for International Services directly to Europe. The central area north of the platform could be opened up to provide check in and security at platform level with access from the concourse above.

Appendix I contains a series of detailed technical reports on birmingham New Street Station.

263

Lee Bank



Km

bIRmINGHAm NEW STREET


wESt mIDlanDS - CEntral BIrmInGHam 10.16.

to tHE nortH-wESt

If a through birmingham route were developed, moor Street would be used as a through station. The route alignment northwards is described below.

Moor Street Exit10.16.1.

A high-level moor Street station could be achieved, placing the station about today’s station level. The route would pass over the New Street Station approach tracks, and then pass under moor Street Ringway, which would have to be raised to create the required headroom. The route would require the acquisition of all property between the Ringway and carrs Lane, involving the demolition of carrs Lane church as well as all other premises as far north-west as carrs Lane.

Moor Street to Ray Hall / Perry barr10.16.2.

At Dale End Road, the route would enter twin single tunnels diving down and turning to the east to avoid the existing moor Street tunnels. This combination of horizontal and vertical alignment would restrict speeds to 100kph, so any non-stop train would face this restriction. A deep-level option under the New Street lines would avoid the geometric restrictions, and would therefore allow a higher maximum speed, at the cost of a much deeper station.

Ray Hall / Perry barr to WCML10.16.3.

The HS2 tracks would emerge from a tunnel portal 1km north of the m6 to avoid Great barr Park, part of which forms a SSSI. Part of Great barr Golf course would be severed. The HS lines would pass to the east of Aldridge, crossing over the existing railway between Walsall and Sutton coldfield before reaching the m6 Toll. The alignment would, unlike a route to the east of Aldridge, avoid cannock chase Forest which contains SSSI’s, Areas of Outstanding Natural beauty and Special Areas of conservation,

At the m6 Toll, the route would be on elevated structure over the motorway and the nearby A5, and then over the existing Lichfield to Walsall railways and the Wyrley and Essington canal.

Once clear of the canal, the route would return to and continue northwards at surface level.

Another viaduct would be required to take the HS2 tracks over the A51 west of the village of Longdon. The route would be on elevated structure on the outskirts of Armitage due to the presence of the Trent and mersey canal, local roads, West coast main Line and River Trent. Horizontally, the route would be fairly restricted between Armitage and the power station.

Connection into the West Coast Mainline10.16.4.

The tie in point of the HS lines into the West coast main Line would be south east of Rugeley.

265

LICHFIELD

BIRMINGHAM

TIPTON

WALSALL

RUGELEY

OLDBURY

CANNOCK

BLOXWICH

ALDRIDGE

SMETHWICK

DARLASTON

WILLENHALL

WEDNESBURY

BROWNHILLS

BLACKHEATH

WEST BROMWICH

SUTTON COLDFIELD


Route0 2.51.25

Km

cENTRAL bIRmINGHAm TO THE NORTH-WEST


HEatHrow oPtIon - EalInG BroaDway10.17.

The HS2 station would be oriented east-west with a platform length of approximately 415m. The station would be directly beneath the existing Ealing broadway Underground and Network Rail Station.

This new HS2 station would be constructed within tunnels bored whilst the station above is fully operational. The station would provide for two non-stopping fast through lines with island platforms on either side giving a total of four platform edges (and six tracks).

Ground movements would be substantial with anticipated hot spots of up to 150mm, and this may not be acceptable to Network Rail or LUL.

267

West Acton

EALING



Km

HEATHROW OPTION - EALING bROADWAY


HEatHrow oPtIon – SoutHall10.18.

A cut-and-cover through station at Southall would be immediately north of the GWmL and 600m west of Southall Station. This station would occupy some railway land (sidings) and some light industrial land (including limited demolition).

In order to achieve the brief for interchange with crossrail and GWmL, the proposal would rebuild the existing Southall Station alongside the new HS2 station.

CaPItal CoSt EStImatES for oPtIonS 10.19.

not PurSuED In StaGE 3

Each option was developed on Ordnance Survey mapping in order to produce centre-line alignments, horizontally and vertically. The routes were then sub-divided into geographical sections of a consistent engineering solution:

“open country” routes in non-•

challenging topography;

“open country” routes in more •


Tunnel sections;•

On viaduct / structure;•

On-line widening in an existing rail corridor •

(where there is a “wide” solum in existence);

On-line widening in an existing rail •

corridor (where the existing width is fully occupied by rail infrastructure);

For underground and surface stations, •

site-specific estimates were produced.

Each link was then divided, such that, for example, a 20km route section could have 2km of viaduct, 3km of tunnel, and 15km of “open route”. The costs were at Q3, 2009 prices.

Quantities were extracted from engineering drawings, while unit rates were drawn from an embedded set of sheets, such that sectional totals could be added to form route estimates.

capital costs for stations were estimated using Stratford International as a benchmark for cut / cover underground stations. For deep “cavern”

stations, estimates were derived from the tunnelling requirements, allowing for the approach tracks and platform requirement. For works involving alterations to existing stations and for elevated stations, works at cTRL St Pancras were used as a guide.

Tunnelling cost estimates were derived for single-bore and twin-bore configurations, but without details of exact sizes, depths, ventilation requirements etc.

The costs included allowances for environmental mitigation, construction on-costs, and HS2 Ltd’s client costs.

269

North Hyde Norwood Green

Dormer's Wells

SOUTHALL



Km

HEATHROW OPTION - SOUTHALL


IntroDuCtIon11.1.

This chapter summarises the options studied in Stage 2, and not carried forward beyond the end of that period in the Stage Gate 2 Review (at July 2009). The chapter does not described routes carried forward, as these have been previously described at an appropriate level of detail.

The routes were:

London Stations•

Willesden Junction (Terminus) –

“Royal Parks 1” - Hyde Park –

“Royal Parks 2” - Regent’s Park –

St Pancras 1 –

St Pancras 2 –

Line of Route•

The midland main Line / m1 corridor –

chiltern Line (South Ruislip to Neasden) –

m40 (Stokenchurch to Heathrow) –

m4 corridor (Old Oak to Heathrow –

chiltern Line/m40 (Princes –

Risborough to Warwick)

m40 Stokenchurch to Warwick –

West midlands Option•

Fully Tunnelled m42 to city centre –

Stechford to Perry bar –

A West midlands Western bypass –

South-Westerly Approaches to birmingham –

Approach from Nuneaton – bedworth Gap –

Through birmingham Routes –

moor Street West –

curzon Street (Through) –

Underground Through Station –

Heathrow Options•

North Pole –

Acton Yard Interchange –

Hayes and Harlington –

GWmL Heathrow Interchange. –

lonDon StatIonS - IntroDuCtIon11.2.

For each station, a “footprint” template was created as an aid to determining the size of the station. Essentially, the requirement was for a 10-platform station, containing platforms of sufficient length to accommodate a 400m length train.

In addition to the track footprint, site-specific thinking was carried out on the passenger circulation requirements, considering concourse levels, other levels for access to the “outside world” and onward access to London Underground, other stations, bus and taxi services. Accessibility was a significant issue in determining station layouts.

The station location was considered in conjunction with the potential approaches, whether tunnelled or otherwise. The location of tube tunnels, particularly, was considered, along with some knowledge of deep basements, plied foundations. Future constraints such as crossrail alignments were known, and influenced locations.

lonDon StatIon - wIllESDEn junCtIon 11.3.

(tErmInuS)

This would be a 10-platform terminus parallel to the West coast main Line. The station would be constructed in cut-and-cover below the existing junction trackwork, served by 2 track tunnels from the north.

This station, as a terminus, would be most compatible with a tunnelled route approaching London from the West coast main Line / m1 / midland main Line corridors but could in fact be served from the Great Western main Line or chiltern Line corridors in tunnel.

In engineering terms, significant costs would be associated with the massive excavation for the 10-track station and diversion / temporary works to maintain the operational junction above. concourse connection costs would be above-ground and, therefore, relatively low.

The station, as a Terminus, would interchange with the WLL and NLL (both serving the periphery of London) and the bakerloo Line which would

OPTIONS STUDIED IN STAGE 211.

271

Harlesden

College Park

Old Oak Common

Willesden Green



Km

LONDON STATION - WILLESDEN JUNcTION


take the majority of passengers to central London. It is not anticipated that a significant number of passengers would use either WLL or NLL since neither serve central London.

In terms of constructability, there is a precedent for this construction (Stratford box) including adjacent lines and structures and lines above. This land, being railway land, is believed available so there would be few land acquisition costs and only limited disruption to NLL and WLL services. There would however be relatively poor road access, both for construction purposes, and for later servicing of the station.

In terms of engineering, this option would be relatively straightforward.

lonDon StatIon “royal ParkS 1” - HyDE 11.4.

Park

This would be a 10-platform terminus station in a cut-and-cover box beneath the Park, aligned north / south. This would minimise land disruption, optimise potential access to LUL and permit the Park to be re-instated above the completed station.

The engineering challenges are few. Access costs would be low, but the concourse would be sited below ground level. The station would be well served by road access and would be constructed conventionally, and the surface later re-instated. The station would, on completion, be completely beneath the reinstated Park, with access points on the Park boundaries. Ventilation structures would remain as a surface feature, perhaps up to 4 storeys above ground.

Whilst there would be no disruption to existing rail services or demolition, there would be significant disruption to areas of the Park to allow for ventilation and vertical station access.

In terms of onward distribution of passengers, this station would have potential links to Hyde Park corner (Piccadilly Line) or, possibly, marble Arch (central Line). However, these two stations are over 1km apart. It would have no potential linkage with other underground routes. This station is not

a significant engineering challenge, but passenger dispersal would be poorer than most other central London locations.

273

Mayfair

Brompton BelgraviaKnightsbridge

MARYLEBONE



Km

LONDON STATION “ROYAL PARKS 1” - HYDE PARK


lonDon StatIon “royal ParkS 2” - 11.5.

rEGEnt’S Park

This would be a 10-platform terminus station in a cut-and-cover box beneath the Park aligned north / south on the Park’s easterly perimeter. This option would optimise access to existing transport corridors out of London, and, being sub-surface, would allow re-instatement of the Park on completion.

The station would, on completion, be completely beneath the reinstated Park, with access points on the Park boundaries. This station could be a new HS2 station or equally a new domestic station taking displaced services from a new HS2 station.

Significant costs would be associated with massive excavation for the 10-track station (track level at -15m) and Park reinstatement over the roof deck. Access costs would be low, and the concourse would be sited below ground level, leaving only “access” structures and ventilation shafts on the surface.

This option would be entirely free from potential disruption to existing rail services.

This station would have links to Regents Park, Great Portland Street and, possibly, baker Street by foot tunnel/travelator which encompasses bakerloo, metropolitan, Hammersmith & city, circle and Jubilee Lines, giving rapid access to London destination and other London stations. In engineering terms, this option would be relatively straightforward, and it would have sensible onward connectional opportunities.

275

Somers Town

Regent's Park

MARYLEBONE



Km

LONDON STATION “ROYAL PARKS 2” - REGENT’S PARK


lonDon StatIon - St PanCraS 111.6.

This would be a 10-platform station constructed immediately above the extended HS1 platform zone, the South East Trains platform zone and Thameslink access. It would be situated north of the barlow train shed and its arched glazed screen. This option would utilise the available transport corridors and site without displacement of existing services.

The station would be served by four tracks above the existing HS1 fan which would descend into tunnel at the earliest opportunity. A vertical crossover, north of the station, with HS1, mainline east and North London junction to the west would enable a tunnel portal to be constructed, subject to an available site.

The notable engineering challenge would be the vertical alignment heading north out of the station. The high-level track fan would need to oversail the existing track fans below before descending into a tunnel portal beyond the North London Line. This would involve demolition of residential property.

Significant costs would arise both from displacement of services and extensive complex construction. The erection of a new deck above the existing would necessitate relocation of services as, by nature, the construction could not be carried out above a live operating station. Further costs would be incurred by locating additional concourse and customer facilities at high level above upper platform level. Roof level would be of the order of +45m.

This option would provide good connectivity to London destinations and other London stations via LUL, being served by Hammersmith & city, circle, Northern (city branch), Victoria, metropolitan and Piccadilly Lines. There would be very good access to HS1 by direct interchange.

There would be very large engineering challenges with this option.

277

St Pancras

Somers Town



Km

LONDON STATION - ST PANcRAS 1


lonDon StatIon - St PanCraS 211.7.

This would be a 10-platform terminus station sited to the north-west of St Pancras with its tracks at the same level as St Pancras International’s tracks. The HS2 station would be oriented north / south. The site is currently occupied by Somers Town – camden Housing and Sir John Soames’s mausoleum and graveyard.

This option would provide a natural extension and interchange with the existing St. Pancras facilities, and would take advantage of a relatively undeveloped site.

The station would be fed by four tracks through an elevated track fan. The fan, adjacent to the HS1 fan would descent into tunnel adjacent to the North London Line. There would be no natural alignment for the HS2 north of St Pancras, however, once in tunnel this option would be compatible with all London approaches.

This option would be compatible with services to Heathrow and connection of HS2 to HS1. It would provide good connectivity to London destinations and other London stations via LUL, being served by Hammersmith & city, circle, Northern (city branch), Victoria, metropolitan and Piccadilly Lines.

279

St Pancras

Somers Town



Km

LONDON STATION - ST PANcRAS 2


tHE mIDlanD maIn lInE / m1 CorrIDor11.8.

At Luton, widening alongside the midland main Line would have major effects on property, development and other infrastructure. The m1 through Luton (at Junction 11) is also contained with dense property constraints. Harpenden, St Albans and Radlett are also huge constraints on a mmL route. Through Hendon and cricklewood, the mmL follows a route that could not realistically be widened, nor could it offer any serious speed potential. All these constraints could be overcome by tunnelling, but given that there are “open country” routes to both the east and west, there would be no merit in taking HS2 through Luton itself. Given these less damaging and less costly options, a route literally following either the mmL or m1 would be impractical, intrusive, costly and disruptive.

281

ST ALBANS

TRING

SANDY

LUTON

RUSHDEN

HITCHIN

BEDFORD

BALDOCK

WENDOVER

ST NEOTS

KEMPSTON

HATFIELD

AMPTHILL

STEVENAGE

HARPENDEN

DUNSTABLE

AYLESBURY

BIGGLESWADE

BERKHAMSTED

MILTON KEYNES

WELLINGBOROUGH

HOUGHTON REGIS

HIGHAM FERRERS

NEWPORT PAGNELL

HEMEL HEMPSTEAD

LEIGHTON BUZZARD

WELWYN GARDEN CITY

LETCHWORTH GARDEN CITY


Route0 52.5

Km

THE mIDLAND mAIN LINE / m1 cORRIDOR


CHIltErn lInE (SoutH ruISlIP to 11.9.

nEaSDEn)

between Ruislip and Neasden, two additional tracks would be needed, as this link is well-used by chiltern Railways’ services. This would be problematic in terms of property, and in maintaining existing train services. It would be difficult to derive an alignment offering the order of speeds required, compared to other route options. consideration was given to tunnelling, but alternative tunnel alignments would provide more realistic and direct routes towards London.

283

HAYES

ACTON

PUTNEY

PINNER

KENTON

HENDON

HARROW

EALING

BUSHEY

BARNES

WEMBLEY

WATFORD

RUISLIP

FELTHAM

EDGWARE

ASHFORD

YIEWSLEY

STANMORE

SOUTHALL

RICHMOND

NORTHOLT

HOUNSLOW

CHISWICK

WILLESDEN

NORTHWOOD

ISLEWORTH

GREENFORD

BRENTFORD

TWICKENHAM

TEDDINGTON

HILLINGDON

KENSAL TOWN

HAMMERSMITH

BOREHAMWOOD

WEST DRAYTON


Route0 21

Km

cHILTERN LINE (SOUTH RUISLIP TO NEASDEN)


m40 (StokEnCHurCH to HEatHrow)11.10.

consideration was given to deviating south from the broad m40 corridor at Gerrards cross to head towards Heathrow.

This route would pass through the chiltern Hundreds, north of Wexham Street, before passing under m25 in tunnel and connecting to the Heathrow hub near the m4 / m25 junction at Yiewsley. It would appear that a surface route would be possible, though there are many property and development constraints. This route could provide a link from the chiltern corridor towards Heathrow, if required.

285

ETON

HAYES

EGHAM

SLOUGH

WINDSOR

WATFORD

STAINES

RUISLIP

FELTHAM

ASHFORD

YIEWSLEY

UXBRIDGE

NORTHWOOD

HILLINGDON

CHORLEYWOOD

WEST DRAYTON

BEACONSFIELD

RICKMANSWORTH

GERRARDS CROSS


Route0 21

Km

m40


m4 CorrIDor (olD oak Common to 11.11.

HEatHrow)

The HS2 train service could not be accommodated on the existing 4-track GWmL Route, and two additional tracks would be needed. It is almost impossible to develop a credible surface route for such 300kph infrastructure, given property constraints, existing railway junctions, freight yards, stations, etc. It was therefore considered that only a fully-tunnelled route could be developed in this GWmL corridor.

287

HAYES

ESHER

ACTON

SUTTON

PUTNEY

PINNER

MORDEN

MERTON

KENTON

HENDON

HARROW

FULHAM

EALING

BUSHEY BARNET

BARNES

WEMBLEY

WATFORD

SUNBURY

STAINES

RUISLIP

FELTHAM

EDGWARE

ASHFORD

YIEWSLEY

UXBRIDGE

SURBITON

STANMORE

SOUTHALL

RICHMOND

NORTHOLT

HOUNSLOW

FINCHLEY

CHISWICK

CHERTSEY

WILLESDEN

WEYBRIDGE

NORTHWOOD

ISLEWORTH

GREENFORD

BRENTFORD

WANDSWORTH

TWICKENHAM

TEDDINGTON

NEW MALDEN

KENSINGTON

HILLINGDON

ADDLESTONE

KENSAL TOWN

HAMMERSMITH

BOREHAMWOOD

WEST DRAYTON

RICKMANSWORTH

WALTON-ON-THAMES

KINGSTON UPON THAMES


Route0 21

Km

m40 cORRIDOR


lInE of routE - CHIltErn lInE/m40 11.12.

(PrInCES rISBorouGH to warwICk)

Northwards from Princes Risborough, the HS2 line could follow the chiltern corridor past the Haddenham and Thame Parkway station area towards bicester.

At bicester, HS2 could not realistically pass through the present station, as there would be major and unacceptable disruption in trying to accommodate 2 new HS tracks within the footprint of the existing station. Inadequate clearances would result, together with major grade-separation works to place HS2 in the middle of the layout. Equally, an “off-line” HS2 closely paralleling the existing lines would be very problematic in terms of property. It was therefore concluded that HS2 could not pass through bicester, but must go around it.

At banbury, as at bicester, it would not be possible (at any realistically high speed) to find a route adjacent to the existing railway. It was therefore concluded that a route around banbury would be needed. The m40 steers a course to the east of the town, emphasising the logic of an easterly bypass. between bicester and banbury, therefore, the route could adopt the m40 alignment, paralleling it very closely.

between banbury and Warwick, HS2 could follow m40 Junction 15 south of Warwick. This route became Route 2, as described earlier. North of Warwick, the route could continue to follow the m40 towards the Dorridge corridor, or could swing north to form a birmingham Eastern bypass. There does not appear to be a significant engineering challenge on this route, except the area south of Warwick.

289

OXFORD

COVENTRY

LEICESTER


Route0 84

Km

cHILTERN LINE


lInE of routE - m40 StokEnCHurCH to 11.13.

warwICk

From the Stokenchurch area, the route would attempt to follow the m40, but this is not likely to be achieved, given the sinuous nature of parts of the m40 alignment. The m40 also took a route skirting the eastern edge of Ot moor, as this was a major constraint on its alignment, and would equally be so for a new high speed railway.

North from Stokenchurch, therefore, there would appear to be two alignments; one following m40 around Ot moor, and the other closer to Oxford’s easterly suburbs, where a Parkway Station might be envisaged.

The easterly of this pair of routes would, like the m40, pass west of bicester, but again could not literally follow the m40 because of its curvature. The route would therefore deviate away from the m40 alignment to pass west of Ardley and Fritwell. It would then join a previously-described route onwards to Warwick.

There would not appear to be a significant engineering challenge on this route, except the area south of Warwick.

291

OXFORD


Route0 42

Km

m40 STOKENcHURcH TO WARWIcK


wESt mIDlanDS oPtIon - fully 11.14.

tunnEllED m42 to CIty CEntrE

This would be a “notional” tunnelled route that could allow access to central birmingham from, generically speaking, the m42 locality. It would only be considered if surface access routes proved very challenging in engineering, disruption or environmental terms.

293

BIRMINGHAM

SOLIHULL

SUTTON COLDFIELD


Route0 21

Km

WEST mIDLANDS OPTION - FULLY TUNNELLED m42 TO cITY cENTRE


wESt mIDlanDS - StECHforD to PErry 11.15.

Bar

A potential route would diverge at Stechford Junction to run to Perry barr (Grand Junction) route. This would require sluing of the existing coventry line to make space for new high speed lines. Stechford Junction would require major remodelling and grade separation. Aston Junction would require grade separation of the Sutton coldfield line (extremely difficult due to vertical space restriction). There would be track configuration issues at Perry barr Junction. It might be necessary to place 5.5km of the route in tunnel.

There would be a major reconstruction of existing railway, which is an important diversionary route when problems arise at New Street. This option would not serve central birmingham.

295

BIRMINGHAM

WALSALL

SOLIHULL

ALDRIDGE

SMETHWICK

SUTTON COLDFIELD


Route0 21

Km

WEST mIDLANDS - STEcHFORD TO PERRY bAR


a wESt mIDlanDS wEStErn ByPaSS11.16.

A Western bypass would start in the m40/m42 Umberslade Junction area and follow the m42 towards Hopwood (m42 J2) and towards the m5 (J4) at Lydiate Ash. The route would run on the southerly side of m42.

The link would only be necessary if there were south-westerly approaches to central birmingham or towards Sandwell, or as part of a genuine Western bypass. None of these appear a sensible way of gaining access to the centre of birmingham in terms of cost, there being much more realistic ways of achieving the link from the m40 corridor to central birmingham.

A Western bypass could continue around the western fringe of the conurbation towards west Wolverhampton, a length of 57km. The route was based on the alignment of the once-proposed birmingham Western Orbital Route (bWOR). Achieving a high-speed railway in this corridor would be extremely challenging. The route would not serve birmingham, and would need to be supplemented by other links to achieve this aim, probably more cost-effectively. This route is also on the opposite side of the West midlands conurbation to the “natural” alignment from London to manchester, which would pass to the east in the m42 coleshill area.

297

LICHFIELD

BIRMINGHAM

WOLVERHAMPTON


Route0 52.5

Km

A WEST mIDLANDS WESTERN bYPASS


SoutH-wEStErly aPProaCHES to 11.17.

BIrmInGHam

It would be possible to use the initial section of the Western bypass to access the Sandwell area by routes through birmingham’s south-westerly suburbs.

There are two broad corridors, one through Kings Norton, Harborne and Smethwick (in a tunnel) and one through Longbridge, Frankley and Smethwick (in a tunnel). Neither would serve birmingham which would need other linkages from the south.

From Sandwell, the route could follow the m6 corridor until it leaves the urban areas, but there would be huge structural works. There would be major demolition along part of the route, and a huge impact on highways. The route would cause major severance, and interference of the whole urban environment and infrastructure.

299

LICHFIELD

BIRMINGHAM

WOLVERHAMPTON


Route0 42

Km

SOUTH-WESTERLY APPROAcHES TO bIRmINGHAm


wESt mIDlanDS aPProaCH from 11.18.

nunEaton – BEDwortH GaP

If an approach from south of Warwick or through the Kenilworth – coventry gap proved to be a challenge, another variant would be a route approaching via the Nuneaton – bedworth gap. This would effectively mean that the main HS2 route approaching from London would probably pass east of, or through, Rugby. This link would approach from the Whitacre area, and would need to find a path avoiding Hams Hall freight terminal, before attempting to use the birmingham to Derby line corridor inwards from Water Orton.

301

COVENTRY

LEICESTER

RUGBY

WARWICK

TAMWORTH

SOLIHULL

NUNEATON

HINCKLEY

DAVENTRY

BEDWORTH

COALVILLE

KENILWORTH

ATHERSTONE

LUTTERWORTH

SUTTON COLDFIELD

ASHBY-DE-LA-ZOUCH

STRATFORD-UPON-AVON



Route0 52.5

Km

WEST mIDLANDS APPROAcH FROm NUNEATON – bEDWORTH GAP


tHrouGH BIrmInGHam routES11.19.

There were a number of “through birmingham” routes, particularly northwards from moor Street. In broad terms:

via the m6 Junction 7 / Perry barr area, •

and then onwards north of Walsall and east of Penkridge towards Stafford, and one passing east of Aldridge to meet the WcmL south of Rugeley;

via Sutton Park / west of Sutton coldfield, •

then towards Rugeley or Hansacre.

The route from Perry barr and east of Aldridge would attempt to make use of gaps in development, but it could be difficult to find a satisfactory route in the Great barr and barr common areas. At the northern end, the route would join the WcmL at a grade separated junction south of Hansacre. The variant towards Stafford would seem to head off in a non-optimum direction.

The Sutton Park route would be a mixture of a surface route, and a tunnel section under Sutton Park and Four Oaks. The surface route would require embankments/cuttings to be constructed to suit the topography. Initial work showed that this route variant via Sutton Park and Hansacre would be a more costly way of fulfilling the same function as the Perry barr route.

303

LICHFIELD

BIRMINGHAM

WOLVERHAMPTON


Route0 42

Km

THROUGH bIRmINGHAm ROUTES


wESt mIDlanDS StatIon - moor StrEEt 11.20.

wESt

This option would utilise the disused platforms on the southwest side of moor Street Station to create a terminal station. The existing disused platforms are approximately 200m long and 7.5m wide. They would require about a 215m extension towards Small Heath to accommodate the required 415m platform length and a new concourse. The existing platforms are narrow so would need to be widened. The track geometry would dictate a very slow entry/exit speed to the new platforms.

There is limited space on the southwest side of the station, so, as a terminus, this option was considered to have only two platform faces, with some operational and capacity restrictions.

It should be noted that there is an aspiration by chiltern Railways to use the presently-unused westerly platforms.

Access to the station and immediate local passenger distribution would be reasonably good.

305

Digbeth



Km

mOOR STREET WEST


wESt mIDlanDS StatIon - Curzon 11.21.

StrEEt (tHrouGH)

This station would be sited on the old curzon Street Station site with throats extending through to the Fazeley Street site to the west and beneath viaducts to the east.

The station would be located at ground level above the canal, and would provide four platform faces.

The alignments to the north would descend rapidly into two tunnels beneath the city centre. To the south, alignments would pass beneath existing viaducts to join the existing rail corridor form the birmingham International direction.

The concourse would probably be situated towards the west end of the station, since the majority of passengers would be associated with the city centre or interchanging with New Street Station; both distances would be typically 1.0km. In this option, all ground-level roads would be severed or disrupted, necessitating bridges above the platform level for cross-site movements.

307

DigbethBordesley

Netchells Green



Km

WEST mIDLAND STATION


BIrmInGHam StatIon - unDErGrounD 11.22.

tHrouGH StatIon

An underground station could be used to provide a through station option with 4 platform faces. The orientation could be whatever was best suited to decisions taken elsewhere about the approaches to, and exits from, the city centre.

Any option would be extremely expensive and difficult to construct. There could be issues over fire and evacuation safety. There are issues of deep foundations which would require further investigation to find a clear alignment. Access to the surface could be difficult, although there would be the potential to connect to New Street if aligned east-west, or to both New Street Station and Snow Hill Station if aligned north-south.

Vibration and foundation stability issues would be likely under city centre properties, but the concept could substantially be constructed without disruption to the existing rail network. It could provide the opportunity for capacity for additional routes, and an International station could be accommodated.

309



Km

bIRmINGHAm STATION - UNDERGROUND THROUGH STATION


HEatHrow oPtIonS - nortH PolE11.23.

This station would be on the site of the former Eurostar depot, and would be a 4-platform station with 6 tracks, of which 2 are through tracks. It would be a below-ground box with tracks at -15m beneath existing railway sidings. This option provides a potential connection to a new crossrail station and thus also the Great Western main Line. The station would be oriented east-west.

This option could provide connection to a crossrail station. A distant connection to a new West London Line station could also be constructed.

The construction of a below ground level box would be relatively straightforward in this location.

311

Old Oak Common



Km

HEATHROW OPTIONS - NORTH POLE


HEatHrow oPtIonS - aCton yarD 11.24.

IntErCHanGE

This station would have 4 platforms and 6 tracks of which 2 would be through tracks. It would be a below-ground box with tracks beneath existing railway sidings. This option would provide a potential connection to crossrail and the Great Western main Line. A link to West Acton central Line station could be constructed and a new Piccadilly Line station could also be built fairly close by. The HS2 station would be oriented east-west. It may be desirable to construct links to or new nearby London Underground stations.

The construction of a below ground level box would be relatively straightforward in this location.

This option was not pursued because it proved impossible to find an alternative facility nearby for relocation of the freight operations already using this locations, and because the nearby Old Oak common location appeared to be preferable.

313

West Acton

North Acton

ACTON



Km

HEATHROW OPTIONS - AcTON YARD INTERcHANGE


HEatHrow oPtIonS - HayES anD 11.25.

HarlInGton

As for all other GWmL-type locations, the station would be oriented east-west. The western throat may need to be constructed below the Grand Union canal. The construction of a below ground level box would be relatively straightforward in this location, except for the issue of any construction under the Grand Union canal.

315

Hayes Town



Km

HEATHROW OPTIONS - HayES anD HarlInGton


HEatHrow oPtIonS - Gwml HEatHrow 11.26.

IntErCHanGE

This would be an HS2 through station (only) on the Great Western main Line. It would be oriented east-west in a box. It would not be the “Arup Hub” which would offer a much wider range of connectional opportunities at a much greater cost. For comparison with other Heathrow Interchange options, this location was viewed strictly as a similar 4-platform station with 2 through tracks. It would be a below-ground box with tracks at -10m probably beneath green field site. The location requires that it would be situated on HS2, or be served by a loop off it. This station option also has the potential to be a parkway station with good links to the m3, m4 and m25.

CaPItal CoSt EStImatES for oPtIonS 11.27.

not PurSuED In StaGE

Each link was costed as if it were a consistent engineering solution (and that is the reason why the links and nodes were chosen to allow this process to occur).

“Per-km” rates were derived, and this rate was then applied to the totality of the link under consideration. The “link types” were:

“open country” routes in non-•


“open country” routes in more •


Tunnel sections;•

On viaduct / structure;•

On-line widening in an existing rail corridor •

(where there is a “wide” solum in existence);

On-line widening in an existing rail •

corridor (where the existing width is fully occupied by rail infrastructure);

For underground and surface stations, •

site-specific estimates were produced.

A base construction cost was derived, and percentage additions were then made for environmental mitigation, contractors on-costs

and other site-related issues. HS2 (client) costs were then added.

Station cost estimates were based on Stratford International or St Pancras.

The civil engineering rates were based on an extensive database built up by Arup over many years, over a wide range of infrastructure schemes.

The costs were at Q3, 2009 prices.

317

Thorney



Km

HEATHROW OPTIONS - GWmL HEATHROW INTERcHANGE


Appendix A Tunnelling Studies

High Speed Two Ltd High Speed 2Final Report

Page A1 Ove Arup & Partners Ltd 15 December 2009

1A Tunnelling Studies A1.1 Assumptions

This chapter provides a summary of tunnels advice worked up during the initial phases of the High Speed 2 project, and to provide a design basis for tunnelling work going forward. In many areas it still leaves many questions that will need to be answered at subsequent stages of design, but it is intended that the level of detail in this report will allow people working on HS2 to make decisions based on a reasonably robust basis.

It is assumed for the purposes of this report that the railway is a twin track railway to ‘GC’ Gauge, with an aspiration to run at 400kph where practicable. It is, however, recognised that 400kph running in tunnel could be extremely expensive, and therefore unjustifiable, and the impact of running at certain speeds will need to considered in the cost-benefit analysis.

A1.2 Summary of tunnel options

The following options have been considered

o Twin bore, single track tunnels with cross-passages

o Single bore, twin track tunnels

A1.2.1 Twin bore, single track tunnels with cross-passages The twin bore, single track tunnels comprises of two parallel bores with cross passages at regular intervals. The internal diameter of each bore needs to accommodate a GC Gauge train and the electrical, mechanical and safety equipment required. The internal diameter of the tunnels and the cross passages sizes and distances are subject to the following requirements:

o Safety regulations.

o Aerodynamics and ventilation.

A1.2.2 Single bore, twin track tunnels The single bore, twin track tunnel comprises a single bore which needs to accommodate two GC size Gauges. For longer tunnels it is likely that a dividing wall will be required for safety purposes. Each section needs therefore to accommodate a GC size Gauge and the electrical, mechanical and safety equipment required. The internal diameter of the tunnel and the emergency doors located in the separation wall are also subject to the following requirements:

o Safety regulations.

o Aerodynamics and ventilation.

A1.3 Proposed construction methodology

Tunnelling for the construction of high speed lines may require different solutions to tackle particular construction challenges. Single, or in most cases, combinations of tunnelling methods may be required to complete a given section of tunnel. This section is focussed on construction of running tunnels and associated structures, rather than tunnelling for underground mined caverns.

The principal tunnelling methods to be considered when constructing the HS2 tunnels may be categorised into the following three types according to the method of construction:

• Tunnel Boring Machine (TBM)

• Mined Tunnel

• Cut and Cover



The selection of the methods is dependent on a number of factors that include:

• Ground conditions, including the presence of groundwater

• Tunnel length and size/diameter

• The need for changes in tunnel geometry or size

• Surface access and sensitivity

A1.3.1 Tunnel Boring Machines Tunnel Boring Machine or TBM is a relatively commonplace excavation method for the construction of utility, sewer, road and rail tunnels. TBMs come in a variety of sizes and configurations and can deal with ground conditions from unconsolidated loose soils to extremely hard rock and very high groundwater pressures. TBMs may be launched from a shaft or from a deep cutting. For this type of project a TBM would more likely be launched from a cutting that would later form the approach ramp for the tunnel, however intermediate construction shafts may also be necessary for longer tunnel lengths. As they remain below ground the use of TBMs can avoid many of the environmental issues that affect shallow tunnels or surface structures.

Tunnelling by TBM relies on excavation within a circular sheild; the tunnel profile created is therefore circular. This means that all elements of the tunnel must fit within the profile of the tunnel, unless the tunnel is later enlarged to accommodate the required changes in tunnel diameter or shape.

The term TBM may be extended to a variety of tunnelling machines. In this case the term TBM extends to two types, open and closed face machines.

A1.3.1.1 Open Face Machines This type of machine relies on some inherent stability of the ground in front of it. Excavation is carried out using a suitable excavator, roadheader boom, or hydraulic chisel within a shield that provides ground support, protection to the workforce and an area to erect the tunnel lining. A typical open face configuration for this type of machine is shown below.

In some types of open face machine additional face support can be supplied through breasting plates that can physically restrain the ground, however this type of machine is not capable of handing higher groundwater pressures and volumes. Other open face machines can deal with water pressure by pressurising the face with compressed air using a bulkhead. A typical configuration for a machine of this type is shown below.



The diameter of tunnel excavated by open face machines is dictated by the reach of the excavating equipment and face stability for relatively large unsupported faces. Open face machines suitable for conventional railway tunnel excavation are available. As the diameter required for high speed tunnel is larger their availability and suitability for some HS2 tunnelling may be limited.

A1.3.1.2 Closed face machines This type of machine is widespread in terms of size, use and ability to cope with a range of ground types and conditions. A typical closed face TBM comprises 4 elements:

Cutting Head - TBMs cut the ground using a circular cutting head armed with picks for soil with rotating disk cutter for rock or a combination of both where mixed ground is anticipated. These are placed on a single cutting head or (for the larger TBMs) two concentric rotating heads. Cutters and their configuration are designed for the different ground types expected.

The configuration of the cutting head also manipulates the excavated material onto the waste handling system that runs inside the TBM.

Drive Section - The drive section houses the hydraulic motors that provide the rotational drive for the TBM and power a series of hydraulic rams in soils and/or grippers in rock to provide thrust. The TBM cutting action requires a thrust to be placed on the cutting head. This thrust serves three purposes:

1. To increase cutting action of the cutters by forcing them into the ground

2. To move the TBM forward through the ground during the cutting cycle

3. To provide a face pressure to support the material in front of the TBM to minimise settlement.

Generally face pressure is required in soils and soft, or broken rocks. Face pressure is often optimised by the injection of pressurised fluids that modify or homogenise the excavated material to allow controlled and consistent face pressure to be applied to reduce ground disturbance due to tunnelling and therefore minimise settlement. This may be achieved using an Earth Pressure Balance Machine (EPBM) or Slurry TBM. These have been successfully employed in a range of soil conditions for major urban tunnels. Schematics of EPBM and Slurry TBM are shown below.



Slurry TBM EPBM

Tail Shield - For the range of ground and groundwater conditions anticipated, a lining will have to be placed behind the TBM to support the ground and to prevent groundwater ingress. This would be erected within a tail shield directly behind the TBM. In this case the lining is likely to be a segmental lining.

Back-up, or trailing gear - The supply of lining and grouting materials and the efficient removal of waste from the TBM is critical to the efficiency of the tunnelling process. TBMs generally pull trailing apparatus that allows simultaneous extraction of excavated material and delivery of lining segments and grout. This is usually consists of a conveyor belt running on top of a gantry system. Transportation of the waste and materials can use small trains or long conveyor belts, depending on the length and diameter of tunnel, the type of waste and the contractor’s equipment.

The back-up generally carries additional items such as grout pumps, soil conditioning chemicals and their pump systems, fire-fighting equipment, ventilation, environmental monitoring and emergency systems. On large machines they include drivers cabins, canteen and ablution facilities. The back-up gear is usually the longest element of the TBM and can be up to 250m in length.

This type of TBM can range in size from less than 2m up to 15.4m for the Shanghai River Crossing in China. TBM can also handle a wide range of ground conditions, including high groundwater pressures (up to 14 bar in the case of the Lake Mead Project TBM in Las Vegas)

TBM Lining

For tunnels excavated entirely in competent and dry rock, no structural lining may be necessary behind the boring machine and therefore no tail shield is required. While there may be areas of rock along TBM alignments and some may be “dry”, it is anticipated that the safety of operating a high speed line would necessitate a lining.

Segmental linings are the most commonly applied lining in the ground conditions anticipated. These are rectangular or trapezoidal segments that, when bolted together form a circular lining. The size and configuration of the ring is dictated by the loading requirements (construction and handling loading as well as ground and groundwater loading).

The segmental lining is grouted in place to maintain its shape, reduce ground displacement and to provide additional waterproofing.



Excavation Sequence

TBM tunnelling involves a two stage cycle to create the tunnel bore.

Stage 1 - Excavation Advance

• The cutting head is rotated against the ground to commence cutting

• Thrust is applied by the rams or side gripper pads in the Drive section to assist cutting and maintain face pressure

• Cutting and advance continues until enough space is created in the Tail Shield to construct the next lining ring

• The gap between the ground and the previous lining ring is grouted as it leaves the tail shield.

Stage 2 – Lining Erection

• The thrust rams are withdrawn into the drive section leaving clear space for the erection of the lining

• Each segment forming the lining is manoeuvred into position and bolted together to form a completed lining ring

• The thrust rams are then re-engaged to commence the next excavation cycle

A1.3.2 Mined Tunnels This method requires exposure of an excavated face and unsupported short advance prior to internal support application. To allow this the ground must either be:

• self supporting or

• treated to allow self support and/or

• pre-supported ahead of excavation

As the face is open, the amount and effect of groundwater is an issue, high inflow rates and pressures can affect the viability of this method.



A1.3.2.1 Excavation sequence A small heading is advanced in a short, unsupported excavation. Primary support is then applied; this may comprise rock bolts and sprayed concrete for rock conditions to sprayed concrete for clays and soils. This initial excavation is then sequentially enlarged by cyclic excavation and lining to form the required tunnel geometry. The excavation may be full-round, with a flattened invert, or with no invert if ground conditions permit. A final lining of sprayed concrete, or cast in situ concrete is generally then applied. The choice of final lining is dependent on factors that include:

• Ground loading

• Groundwater pressure

• Waterproofing requirements

• Internal loading on the lining (fixings and attachments)

A two-phase excavation sequence with heading and bench is shown below. Depending on ground conditions this may be suitable for running tunnels within the range of sizes identified for HS2, however the face may be broken up into more advances for larger tunnels.

As the shape and sequence of excavation are variable this method allows variation in the size and shape of the excavation. It therefore lends itself to creating special areas where this flexibility may be required, such as:

• Local enlargements to accommodate elements such as sumps or transformer and signal control locations

• Turnout structures

• Creating cross passages

• Complex junctions



The method is cyclic and often requires a two-pass lining and may not be suitable for variable ground conditions where lengths of groundwater ingress or soft soil may be experienced. However with a short set-up time and without the large capital cost and lead time associated with TBM procurement and set-up, this can be an economic choice for shorter tunnel lengths. By precedent where both methods are feasible, the use of mining becomes directly comparable to TBM at tunnel lengths of less than 1km. For longer tunnels with variable or unsuitable ground condition for mining the main method for excavating running tunnels is considered to be using open or closed face TBM.

A1.3.2.2 Excavation Method The excavation method for mined tunnels depends on the ground conditions. Hard, competent rock may require drill and blast excavation. Softer or fractured rock may allow roadheader excavation, and clays and soils could be excavated by back-actor. To some extent the method of excavation may be changed during excavation to suit ground conditions.

A1.3.2.3 Extending the range of the method As stated previously the viability of this method is dependent on ground conditions. It is often necessary to introduce additional measures when mining to allow construction. This can be a particular issue for creating elements such as turn-outs where the location may be fixed by operating requirements and there may be limited flexibility to move the structure to more suitable ground conditions. The following methods can be considered where necessary:

• Dewatering – The stability of a face and therefore the ability to mine can be greatly improved by dewatering. This can be from the surface or from within the excavation and may be passive (underground) or actively pumped. This may not be suitable where high water flows and recharge are anticipated, or where dewatering may cause settlement

• Forepoling/Spiling – This is a method of increasing the stability of an excavation by installing forepoles or spiles into the crown of the excavation. These tend to simply span between the supported excavation and undisturbed ground ahead of the face. It must be used in conjunction with other methods if groundwater is a problem

• Face Nailing – Similar to forepoling and spiling, face nailing places mechanical anchors in the excavation face to improve the mass strength of the ground. It is more suited to fractured rock and stiff soils. It must be used in conjunction with other methods if groundwater is a problem

• Systematic Grouting – The injection of grout, generally cementitious, into the ground can improve the strength and reduce permeability. There is a range of grouting techniques available to the designer for different ground conditions. However there are costs and risks associated with grouting and it is generally used for treating distinct areas or ground features.

• Ground freezing - Ground freezing has a considerable track record for stabilising soils for shafts, deep excavation and tunnels in soft, saturated ground conditions. Most applications are targeted at individual locations, such as enabling works for tunnel launch sites or intersections, protection of sensitive structures from the effects of tunnelling, or in localised areas of difficult ground. When used in “production” tunnelling it can be a slow and very expensive method.



A1.3.3 Cut and Cover Cut and cover tunnels are shallow tunnels constructed in a trench. Prior to excavation, buried utilities and services crossing the route have to be protected or diverted. Permanent utility diversions are used to avoid the tunnel alignment where possible. When this is not possible these utilities may be temporarily raised over the alignment clear of construction and then reinstated. For gravity sewers this may involve temporary pump installation to pump over the excavation prior to reinstatement.

The cut is constructed in a number of ways, depending on the support requirements of the ground. In hard rock this may be vertical walls supported by rock bolts and sprayed concrete. In soft rocks and soils stable slopes may be created by excavating benches or batters. If surface space is restricted, or the disturbance caused by construction needs to be minimised then retaining walls can be used to stabilise the excavation. These may be permanent and incorporated into the final structure or temporary and removed after the tunnel structure has been completed.

In the conventional “bottom-up” method the excavation is progressed to full depth, using anchors or bracing struts to provide temporary support to the retaining walls until the tunnel floor and roof slabs are cast.

Alternatively a “Top Down” sequence can be adopted where roof slabs are cast as a strut for the retaining walls. Excavation beneath this slab is carried out through access holes until the base slab level is reached and cast. Generally where long lengths of relatively narrow running tunnel are to be constructed using cut and cover, the more conventional bottom-up technique is used.

Once a stable open cut has been constructed, the tunnel structure is fabricated in the trench. This structure is generally constructed from reinforced concrete using large forms. Once the tunnel floor and roof slabs are cast, temporary struts can be removed or temporary anchors de-stressed. The tunnel roof could also consist of bridge beams placed on the tunnel walls that act as abutments. The use of precast concrete arch roof structures is becoming more commonplace in C&C tunnels. Once again provision can be made to facilitate land redevelopment above the tunnel.



After construction, fill is used to reinstate the ground surface. Where possible reinstatement should be carried out with stored material from the cut stage. C&C tunnels by nature usually have sufficient self weight and overburden to prevent floatation. However, in ground conditions with a high water table the design would have to cater for the effect of flotation and uplift forces on the base slab, this can involve tension piling in some cases, or permanent dewatering as implemented for Stratford International Station box.

In some cases the retaining walls and cut and cover tunnel may form the foundations for new buildings to be constructed above the tunnel.

As surface excavation and wall support are the key cost elements of construction where possible both running tunnels (and any escape provision) are generally included in a single structure.

A1.3.4 The Effects of Tunnelling The construction of underground structures, entirely from below ground or from the surface, may cause ground movement. The degree and impact of any settlement must be understood and built into the alignment selection and design, along with any appropriate mitigation measures. Key elements of this assessment are:

1. Demonstration that the environmental effects of tunnelling induced ground movements have been considered and taken account of in the design.

2. Assessment of the risk of damage to utilities.

3. Assessment of the effects of tunnelling to existing underground tunnels.

4. Assessment of building damage risk and where required investigating alternative designs and mitigation measures

London Underground, Network Rail and other key infrastructure operators may have specific requirements in terms of demonstrating the effects of tunnelling. Each will have to be consulted and appropriate AIP documentation supplied

Settlement can be generated from a number of sources, including:

• Stress changes in the ground due to tunnelling

• Reduction in groundwater levels leading to consolidation

Generally settlement risk during tunnelling will be confined to soils and soft rock. Where competent rock is concerned, settlement must be assessed if there is a risk of settlement due to groundwater lowering or if the excavation is shallow enough that excavation convergence can reach the surface. In general ground displacement in these conditions is less likely. For rock tunnelling conditions, individual assessments will be made on ground-specific risks. For soil and soft rock conditions the following procedures will be followed.

A1.4 Fire Safety Engineering

A1.4.1 Design Guidance The following guidance documents provide recommendations on fire safety design for high speed rail tunnels:

• ‘Technical Standards for Interoperability’ (TSI) ‘Safety in Rail Tunnels’ 2008/163/EC. March 2008. The TSIs are minimum requirements for rail tunnels across Europe, in addition

• ’The Railway Safety Principles and Guidelines’ (RSPG), Part 2, Section A, Guidance on Infrastructure, HSE, 1996 provides additional recommendations for rail tunnels in the UK.

The key minimum requirements from the TSIs for tunnels are:



• The TSIs apply to tunnel between 1 and 20km in length, tunnels greater than 20km require a special safety investigation to determine if additional safety measures are required.

• For two consecutive tunnels to be considered separate, a gap of 500m is required between the two tunnels that is open to air and is provided with egress routes.

• For the purpose of passenger evacuation and fire brigade access, vertical exits to surface should be provided at least every 1000m and should have a minimum width of 1.5m and height of 2.25m.

• Cross-passages are located at least every 500m and should have a minimum width of 1.5m and height of 2.25m.

• The width of access routes for the emergency services should be at least 2.25m.

• Escape walkways are required in tunnels these should have a minimum width of 750mm (it should be noted that RSPG recommends walkways of 850mm).

• Handrails are required to walkways and should be 1m above the level of the walkway and should not encroach onto the recommended clear width.

• Trains should be capable of running for 15minutes at 80km/hr; this is to enable a train to exit a tunnel that is 20km in length.

• Rescue areas of at least 500m² should be provided adjacent to fire service access points, this area can include existing roads.

• The key recommendations in the RSPG for rail tunnels are:

• For horizontal escape at tunnel level, walkways should be provided, based on the recommendations outlined in the RSPG, the walkways should have a minimum width of 850mm. (It is noted that the TSI recommends a slightly less minimum width of 750mm).

• RPSG recommends a low level access walkway between the tunnel wall and tracks, this is to provide the emergency services with access past the train and access beneath the train. The access walkway should have a minimum width of 450mm at foot level (800mm at shoulder level) with a minimum height of 2m.

• The vertical exits should be designed as fire fighting shafts which should include a stair, and lobby. The lobby should be ventilated to keep it free of smoke and be designed in accordance with BS5588-5. It should be noted that BS5588-5 requires pressurisation to shafts greater than 10m deep,

• Where the depth of the shaft is greater than 9m a fire fighting lift should be provided in addition to a stair

• A ventilation system will be provided which is capable of controlling the movement of smoke in an emergency.



A1.4.2 Tunnel Configuration There are two principal tunnel configuration options being considered by the design team:

1) Twin bore - two individual bore containing a single track which are connected by intermediate cross-passages and,

2) Single bore - a single bore containing two tracks which are separated by a dividing wall.

The two tunnel configurations are compared below, based on evacuation and access for the fire brigade.

In the event of a fire on a train within a tunnel, the general aim is to avoid stopping the train in the tunnel and instead continue running the train to outside the tunnel confines, where fire brigade intervention and evacuation can be best dealt with.

In the worst case scenario of a train on fire becoming immobilised within the tunnel, the approach is to evacuate passengers out of the incident area as quickly as possible. This may be via a nearby vertical evacuation shaft leading to ground, via the tunnel portal or from the fire-affected tunnel (often referred to as the ‘incident tunnel’) to the non-fire affected tunnel (‘non-incident tunnel’). Provided the two tunnels are fire and smoke separated it is possible to consider the non-incident tunnel as a place of relative safety.

Twin Bore Tunnels

In the twin bore configuration, the benefit is that cross-passages linking the tunnel can be used by passengers to evacuate from incident to the non-incident tunnel (bore). The cross-passages can be designed as protected routes which are fire separated from each or the bores by fire resisting doors at each side of the cross-passage. The cross-passages may also be pressurised to prevent smoke entering the cross-passages area as passengers are escaping. Once within the non-incident bore, passengers are considered to be in a place of relative safety from where they can be rescued or continue self-evacuation to reach a vertical evacuation/intervention shaft or the tunnel portal.

Twin Bore Configuration - Section View



-

Twin Bore Configuration - Plan View

Single Bore Tunnels

In a single bore configuration, typically the bore will be subdivided by a central wall and a single door will separate the incident and non-incident tracks. To adopt a strategy where passengers evacuate from the incident side to the non-incident side of the tunnel (as outlined for the twin bore configuration above) it will be necessary to prevent the movement of the products combustion, smoke and heat, between the two tracks whilst passenger are evacuating. This could be achieved by creating a protected route between the two tracks in the form of a lobby which provides access to the cross-passage doors; however the interface of this lobby with the train envelope would need to be carefully considered. Additionally, as the walkways are located in the centre of the tunnel the intervention shafts should connect to both walkways to enable the passengers to escape and also the fire service to enter the tunnel.

Positioning the intervention shaft will require local widening of the tunnel to accommodate the shaft between the tracks; this is not practical due to the turning radius of the train. It may be possible to provide the doors into the non-incident tunnel and not provide any intervention shafts, if this approach were to be adopted an alternative method for evacuating the occupants and allowing the emergency services to enter would be required e.g. evacuation train.

An alternative approach that is in accordance with the recommendations of the TSIs would be to provide the walkways on the outside of the running tunnels. As the occupants would not be able to pass into the non-incident tunnel the walkways would need to be constructed as a place of relative safety therefore the walkways would either need to be protected corridors or provided with smoke control to maintain the escape route free of smoke. Where intervention shafts are provided, two stairs will be required one to each of the running tunnels. An example of where this has been done before is the Groene Hart Tunnel in the Netherlands (see figure below)



Single Bore Configuration – Cut away view (Groene Hart Tunnel)

Single Bore Configuration - Plan View

A1.4.3 Tunnel Case Studies Providing cross-passages and intervention shafts in accordance with the recommendations of the TSIs will result in approximately 24 intervention shafts and 48 cross-passages based on tunnel length 26km. The following section summarises what has been provided on recent projects in terms of cross-passages and intervention shafts to inform the design team of what may be acceptable. However, any departure from the TSIs would require approval from relevant authorities such as the local fire brigade.

Channel Tunnel

50km tunnel between England and France consisting of two running tunnels and a separate service tunnel located between the two running tunnels. Cross-passages are provided between the running tunnels and the service tunnel every 375m. There are no intervention shafts - passenger escape and fire service access is provided via the service tunnel. The service tunnel is pressurised to prevent the ingress of smoke from the incident tunnel



CTRL/HS1

The Channel Tunnel Rail Link used a Quantified Risk Assessment (QRA) to inform the design decisions in relation to fire safety measures, and in particular intervention shaft and cross-passage spacing. The CTRL route original design included a 20km tunnel section, which was subsequently sub-divided into two 10km long tunnel sections by introducing a central open section (Stratford box). A QRA was used to demonstrate that an intervention shaft spacing of 3km and cross-passage spacing of 750m provided adequate passenger escape facilities. A service tunnel is not provided (the non-incident tunnel is used to provide a place of relative safety).

The key safety features of the CTRL tunnel design are summarised below.

• Operating procedures require an incident train either to stop before entering the tunnel, or to or to continue through the tunnel if it is safe to do so.

• Design standards for rolling stock and infrastructure use materials of low combustibility and low smoke generation potential. (Testing showed that the design is fully resistant to a 7 MW fire).

• Use of fire-hardened tunnel segments incorporating steel and polypropylene fibers.

• Emergency smoke control system is provided. The non-incident tunnel to be maintained at a higher air pressure to keep out smoke, and act as a safe haven.

• Fire service access, either from the portals or from intermediate vent shafts, and fire protection systems, such as the continuous fire main, are provided.

• Secure radio communications enable direct contact between the driver and the signalling centre at all times.

CTRL Tunnel during construction, showing cross-passage

Groene Hart Tunnel

The Groene Hart tunnel has a length of 7.5 km and has a 15m outer diameter divided single bore twin track setup. It has doors in the dividing wall every 150m and an escape stair every 2km resulting in 3 escape stairs over the length of the tunnel, escape routes are also available via the tunnel portals. It is 30m deep through out its length in order to avoid disturbing the farm land and the underground water ways above.

The passengers escape from the incident tunnel into the non-incident tunnel via the cross-passage doors into the non-incident tunnel. As the tunnels are provided with smoke ventilation there are no lobbies between the two running tunnels. The ventilation system is designed to direct the smoke in one direction enabling the occupants to escape in the opposite direction. The emergency services are able to enter from the same direction as the occupants have escaped.



Groene Hart tunnel during construction – showing locations of walkways and central dividing wall

Groene Hart tunnel showing walkways and doors through to adjacent tunnel and to shaft

Crossrail

The Crossrail scheme consists of twin bore single track tunnel, there are 8 stations along the tunnelled section of the route. Intervention shafts are also provided between the stations. The maximum distance between either two stations or an intervention shaft and a station is up to 2150m. Smoke ventilation systems are provided in both the incident and non-incident tunnel. Cross-passages are provided in accordance with the recommendations of the TSIs.

North Downs Tunnel

The tunnel is 3.2 km in length. It is a single bore, twin track tunnel with no dividing wall. The internal width of the tunnel is approximately 12.75m, with a height of approximately 10.5m. There are no cross-passages or ventilation shafts provided within the tunnel.

A1.4.4 Shorter Tunnels Tunnels that are greater than 1000m long should comply with the recommendations in the TSIs and therefore should be provided with cross-passages and intervention shafts. However, it is likely that some tunnels will be in the region of a couple of kilometres long and constructed of sufficient diameter such that the train is not required to slow down as it enters the tunnel. For these short sections of tunnel it may be possible to not provide any cross-passages or intervention shafts on the basis that:



• A HS train takes in the region of 7km to stop from full speed

• If the fire is detected as soon as train enters tunnel and the brakes are applied the train will have passed through tunnel before it comes to a stop.

The length of the tunnel that this approach can be applied to is difficult to quantify at this stage as it will be a function of the braking distance of the train which is a function of the speed of the train. In addition it will be necessary to design the system to prevent a train stopping in a tunnel. Should a fire be detected on a train just before the train enters a tunnel there will need to be controls to ensure the brakes cannot be applied and that the train passes through the tunnel before it stops.

It is worth highlighting that the longer the tunnel, the longer the distance when the train cannot stop and therefore the longer the period of time for a fire to grow before the occupants of the train can be evacuated. Therefore a qualitative risk assessment would need to be carried out to demonstrate that this approach is not putting the occupants at undue risk.

As this approach has been adopted for the North Downs tunnel which is 3.2km in length we would be fairly confident that this approach can be applied to tunnels up to this length however this would be subject to discussions with local approving authority. Depending on the speed of the train and the results of a qualitative risk assessment it may be possible to apply this approach to tunnels up to a length of about 5km. However, it should be noted that as this is untested tunnels longer than the North Downs tunnel and therefore there is a greater approvals risk.

A1.4.5 Engineered Solution An alternative approach to following the TSIs is to develop a fire engineered solution for the tunnel. Due to the speed at which the trains are running, a qualitative risk assessment approach may be adopted to demonstrate that should a fire occur in a train that it will only stop either at the London station or at the portal. Whilst this approach presents significant opportunities for cost savings to the project it is not financially prudent to include it at this feasibility stage. However this approach should be investigated further during the design phase.

A1.5 Tunnel cross section (for structure/gauge only)

The specification requires the railway to be able to run ‘GC’ Gauge. The tunnel cross sections have been designed in order to accommodate the maximum outside dimension of the wagons based on the static and kinematic gauge envelopes for a GC Gauge. The following figures present the GC Gauge profiles (from Official Journal of European Union, L344, Annex C, 8 December 2006).



Static GC Gauge Profile

Kinematic GC Gauge Profile The minimum tunnel diameter required to incorporate a single track and appropriate fire safety features (walkways etc.) is 7.10m (internal diameter).

A1.6 Portal structures

For HS2 tunnels, the portal structures are designed to retain an open excavation sufficient to allow the launch or recovery of the tunnelling machines. This may involve the provision of a short length of tunnel to act as a launch or reception chamber, particularly where low cover, or poor ground is encountered. It may also perform other construction related functions that would have to be incorporated in the portal and its vicinity. These would include:

• TBM set-up or dismantling area

• Tunnelling logistics and support including

o Segment storage and handling yards



o Spoil management and transportation

o Grout mixing and filling

o Water/compressed air pipe work

• Tunnel Construction Ventilation

• TBM power supply (11 kV supply)

• Stores and spares

• Workforce welfare facilities and transportation

Tunnelling machines may also be launched and/or recovered from intermediate working shafts on longer lengths of tunnel. These are generally combined with ventilation or intervention shafts where possible. The need for intermediate working shafts will depend on the overall length of tunnel in each area, the availability of suitable working sites and the contracting strategy for the tunnelling works.

After completion of the tunnelling works the portal will provide the permanent ground retaining structure and may also have the following functions:

• Emergency egress/access points

• Access/egress for maintenance and inspection

• Ventilation discharge or intake

• Tunnel drainage discharge points

• Transformer locations and tunnel systems control points

• Tunnel access security

It will also form the transition into free-air so must also recognise factors such as aerodynamics, noise management and visual intrusion. The completed structure for the portal may be significantly different from its construction stage layout and may include a slab installed and backfilled, meaning the construction portal may be in a different location to the permanent portal.

To create a portal, sufficient depth of ground must be reached to allow tunnelling to commence. The minimum cover required is discussed. The nature of the ground retaining structure depends on the stability of the ground, which is influenced by soil/rock type, depth, the presence of groundwater and the space available for the portal. Two standard types of portal have been presented in this report, a retained cut and battered slope approach. The construction methods for these may involve a number of geotechnical ground retaining approaches from basic slope stabilisation to Piled or Diaphragm retaining walls.

Tunnelling will commence from the headwall of the portal. This wall must be designed to both maintain ground stability and to avoid eccentric or point loading of the tunnel lining as the tunnelling process enters or exits the portal. To achieve this it is common (but not obligatory) to create a “launch eye” to facilitate breaking out the wall. If the tunnelling machine is to launch from the wall pre-support can be installed with a soft eye (unreinforced or glass fibre reinforced area in the wall) with a supporting ring beam, or waling beam to provide additional retaining wall support. It is also sometimes necessary to carry out ground treatment on the ground-side of the headwall to allow the TBM to break into or out of the headwall under atmospheric pressure (rather than having to operating in EPB or pressurised slurry mode).



A1.6.1 Minimum cover For rail projects in urban areas it is often advantageous and sometimes necessary to commence tunnelling with relatively low cover. The ability to commence tunnelling from a portal location influences the viability rail alignments. It is necessary at this stage to ensure that portal locations and therefore related alignments are feasible.

The current alignment options and portal locations have been based on a simple “rule of thumb” of one tunnel diameter of ground cover above the tunnel at the portal location. Applying a simple rule is appropriate for the development of alignment options at this stage of design, but introduces risk of significant alignment change during option development stages.

It is recognised that there can be significant variation of both the quality and amount of ground cover above the tunnel when further data and site investigation is carried out; and that each portal location will have its own particular opportunities and design challenges. The quality of the ground cover and the sensitivity of the surface to settlement influence the requirement for added excavation support or risk mitigations measures. Each location should be examined and evaluated on an individual basis later in design.

To limit the risk and impact of changes there is a suite of generic options available to create portals and commence tunnelling. It is not yet appropriate to evaluate and select preferred methods, although these options may be used to give reassurance that alignments can be selected or rejected and later developed with a minimised risk of later changes to portal location and alignment.

A1.6.1.1 Portal Options If the alignment cannot be selected based on one diameter, or the ground conditions prove to be less favourable than anticipated, then there are a range of measures to either mitigate the risk of launching the TBM in these conditions, or to pre-install and launch chamber for later TBM launch. These measures can be broadly separated into two types;

o Surface intervention – where mitigation measures are used at surface prior to TBM launch

o Pre-installed launch chamber – where an underground chamber is created that protects the surface from later TBM launch

It may be necessary to utilise a combination of these methods to achieve the required level of surface protection. Each portal location will be considered on its own merit later in the design process.

A1.6.1.2 Surface intervention This approach seeks to improve the response of the surface to stress changes and associated movement from tunnelling. These range from removing the surface entirely, to increasing the robustness of each surface structure affected and combinations of methods may be required. These approaches are discussed below.

Do nothing – If there are no sensitive structures or utilities it may be acceptable to allow significant settlement above the tunnel alignment.

Ground treatment – If the ground is suitable its strength can be improved by the injection of grout. This is generally cementitious, however a range of different grouts are available for a range of applications. Grouting may be achieved from surface, the portal in advance of tunnelling, or during excavation.

Move and Reinstate – If surface structures or utilities are sensitive to movement, they may be removed prior to tunnelling commencement and then reinstated after completion as necessary.

Spanning structure – Foundations of structures and utilities can be isolated from the effects of tunnelling by spanning across the potential settlement trough, or by installing foundations that bear on strata at or below tunnel axis level, this situation is shown in Figure ##.



A1.6.1.3 Launch/recovery Chamber Where shallow excavation must take place there are a number of ways of creating a short length of pre-installed tunnel that allows the TBM to be launched into ground of adequate cover and quality to mitigate settlement risk at the start of a tunnel drive. The approaches available rely on alternative techniques for tunnelling, principally the use of cut and cover and mined approaches as discussed in Section Error! Reference source not found. and Section Error! Reference source not found. respectively. Launch and recovery chambers are often required when a TBM is to be launched from a mid tunnel working shaft, in these cases a “back-shunt” may also be required to provide adequate marshalling space for trains servicing the TBM.

Cut and cover – This would effectively require the extension of the portal in open cutting to the TBM launch point where sufficient ground cover and quality is available for TBM launch. This does rely on the surface being available for cut and cover, however such works can be constructed and the surface reinstated well ahead of the main tunnelling works.

Mined – Generally if the ground cover and quality are sufficient for a basic mining approach, they are generally suitable for TBM launch. As TBM operation is often achieved with less ground movement and risk than mining the TBM would generally be chosen over mining. However there are techniques that can pre-install support ahead of mining than can facilitate mining with low ground cover. One particular method warrants description, pipe canopies can be installed over sections of the tunnel to be excavated using drilled or microtunnelling methods. As there is no retrieval pit the other end of the canopy installation will require blind drilling methods to install such as pipe ramming or auger boring. Pipes in the canopy may be structurally linked by clutches to form the arch and maintain alignment. The function of a canopy may be two-fold; spanning between the unexcavated ground and the install lining and/or forming a structural arch to support the ground. The canopy will be supported by the initial lining as construction advances, although this may be omitted in some cases if the canopy forms a structural arch. A schematic of a pipe canopy is shown below.



If the ground is of sufficient quality the use of forepoling may be considered to assist in mining the TBM chamber. In this case the crown is supported by drilling in steel spiles that bridge between the unexcavated material and the supported excavation. Stability may be enhanced by techniques such as dewatering where appropriate.

The TBM may be launched or received into a headwall at the end of the launch chamber, meaning the launch chamber is basically an oversized section of tunnel; if this section of tunnel is to be left as is, then is constitutes part of the permanent works and must be design as such. Alternatively a segmental lining may be erected behind the TBM and then grouted into position; the chamber may therefore constitute temporary works.

To some extent the choice of excavation and support method and the size of the launch chamber will depend on the contractor’s means and methods and their preference for launching the TBM, particularly if the chamber is developed as temporary works. It is however necessary that the range of options at each portal location be evaluated and narrowed to a manageable set of options that manage the particular settlement and stability risks at each location.



A1.6.2 Width As the construction portal and the permanent portal have different functions and different limitations they may be in different locations along the alignment. It is therefore necessary to consider each individually.

A1.6.2.1 Construction requirements To allow the launch of a TBM or start chamber from a headwall the width required is dictated by the working space required at the base of the portal structure and the space required to form a stable cutting. The cutting may have vertical or battered sides; however the particular Geotechnics of each site will be evaluated to assess space requirements.

The working width at the base of the portal will depend on the alignment and may be varied to suit the available space at the portal location. It is however necessary at this stage to make working assumptions for the space required. If the running tunnels are to be in a single TBM drive with a dividing wall then the portal width should be sufficient to allow the TBM to approach and enter the headwall. In some cases it is necessary to carry out some of the TBM assembly in the cutting; although the TBM can be “walked” into position from an assembly point further up the cutting therefore a working assumption of 1.5 times the diameter of the TBM or starter chamber will be assumed.

For twin bored tunnels the spacing of the two bores is assumed to be 0.5 times the TBM or starter chamber diameter to the inside face of the portal cutting, with one tunnel diameter between the bores. This may be reduced if required, particularly for TBM reception. There is significant precedent for this from projects such as CTRL as shown in Figure ##

CTRL TBM reception portal

The proposed basis for design is shown graphically in the schematic below.



A1.7 Underground (cavern) high speed turnouts

A1.7.1 Geometry A cavern solution has been considered for high speed underground turnouts. The geometry of the turnouts was assumed to be as shown below, with a radius of 3550m at a crossing angle of 1:46, based on work carried out by Rail Link Engineering for HS1. It should be noted that faster turnouts would make any cavern significantly longer.

Geometry of the turnouts (Rail Link Engineering, 1997)

The proposed underground turnout structure comprises a cavern formed with Sprayed Concrete Lining (SCL) as shown below. The main cavern bifurcates into a “binocular” tunnel as shown in Section B-B which is formed from a TBM segmental lining tunnel (through train tunnel) paired with an SCL excavation for the stopping train tunnel.



Turnout cavern sections

It is assumed for the purposes of this exercise that the tunnels will have an outside diameter of 8.2m. With this, the maximum cavern span at Section A-A will be in the order of 17.4m. We believe that this size of cavern would be the largest ever attempted in soft ground in London, and it would at best represent a significant technical challenge under densely populated urban areas. Therefore we do not think that this solution is suitably robust to be considered at this stage of the project.

A1.8 Underground (cavern) stations

The configuration and construction of underground stations is a complex interaction between train and passenger provisions and the particular constraints imposed by the surface use and availability. In urban areas this often means compromise and modification of plans as the station is designed. Many stations for sub-surface railways have been constructed as mined stations where most of the station is tunnelled, however the space, passenger circulation space and ancillary space needed for high speed railway stations often means they are constructed by cut and cover.

Mined stations have distinct advantages over cut and cover-based stations:

• They can be constructed with less surface disruption

• The constraints of an underground environment can be more easily accommodated. Platform and circulation tunnels can be fitted in and around existing underground infrastructure subject to confirming the effects of tunnelling are acceptable

• They are generally more adaptable in terms of station entrance location and configuration

Disadvantages include:

• Significant surface areas are generally still required for vertical circulation, ticketing, ancillary and ventilation space

• Settlement risk must be managed and collapse risk minimised

• It is difficult to achieve “open” architecture and the space may be perceived as less attractive than can be achieved in cut and cover stations



• The requirements for enough cover to mine with acceptable levels of settlement mean that mined stations are generally deeper than their cut and cover equivalents. This increases vertical circulation distances

• Cut and cover stations generally have more flexibility for construction in poorer ground conditions than mined stations.

The feasibility for fully or partially mined stations is likely to be controlled by the ground conditions and the effects of tunnelling on surface structures. As the volumes excavated for platform and concourse tunnels are larger than running tunnels the settlement induced can be proportionally greater.

A1.8.1 Station Requirements The operational requirements for a station will dictate how many platforms and associated approach switches will be required. A number of possible platform configurations will be required for HS2 stations, depending on station function, e.g. terminal or through stations. Generally all high speed stations are likely to require more than two platforms, with terminal stations requiring more. The current assumption is that a through station, such as Willesden will require a minimum of four platforms.

There are various configurations of tunnels and excavations possible for mined stations. The type of station largely depends on the maximum size of opening possible in a given ground type and cover. The size of platform tunnel will also be dictated by:

o platform space required for passenger circulation and emergency egress

o architectural and aesthetic requirements (cladding allowances etc)

o station fit out and systems (wayfinding, lighting, conduit routing etc)

o the aerodynamic requirements for potential high speed passage through the station (through stations only)

A1.8.2 Generic Mined Stations The generic types of station configuration are discussed below. For stations requiring more than four platforms, the basic two track station unit can be replicated to the required number of platforms.

Type 1 – Side Platform tunnels with concourse tunnel This configuration is perhaps the most common, used in urban metro schemes such as Heathrow Express and London Underground. It represents the lower bound for excavation size and can therefore be created with lower cover (therefore creating a shallower station) and in correspondingly poorer ground than the other types of station configuration. Vertical circulation is generally achieved via deep boxes that connect to the concourse tunnel. These may be a single central box, or boxes at each end, depending on entrance location and circulation requirements. The deep boxes also hold ancillary space in the permanent case and allow construction access during construction.

Even with the minimisation of underground space, platform and concourse tunnels are likely to be larger than current London Underground and Heathrow Express tunnels and indeed larger than the proposed Crossrail platform tunnels which are approximately 12m in diameter.



Type 1 four platform station

Concourse circulation for up and down line platform (blue and green).

Up/down line cross circulation may have to be via surface route

Prague Metro

Heathrow Express

Type 2 – Side platform with platform tunnel circulation Passenger circulation can be incorporated into the platform tunnel by increasing its size, negating the need for concourse tunnels. Circulation may be along the platform, or via a mezzanine level (as used on the Lisbon Metro shown below). As with the Type 1 station, the vertical circulation is generally achieved using deep boxes.

With the increasing size of platform tunnel the requirement for sufficient cover and ground quality increases.


Platform tunnel circulation for up and down line platform (blue and green).




Lisbon Metro – Single track platform tunnel with mezzanine

Type 3 Stations – Single two-track cavern If ground conditions allow, then platform tunnels can be combined into a single open cavern containing two-tracks. Platform configurations may be island or side platform as shown below. Passenger circulation can be via the platform, full or partial mezzanine, with vertical circulation via central deep box, or deep boxes at the ends of the station.


Platform tunnel circulation for up and down line platform (blue and green).


Rome Metro - Single cavern island platform

Rome Metro - Single cavern with platform circulation



Bilbao Metro – Single platform tunnel, side-platform with partial mezzanine

A1.8.3 Construction techniques

A1.8.3.1 TBM Station Construction The construction of station platform tunnels for any of the three types of station is not considered suitable as the primary working assumption for mined stations due to the following factors:

o The size of platform tunnel required means a TBM of in excess of 9m diameter is likely to be required. This is towards the upper end of common TBM size and therefore is likely to make this approach uneconomic due to the cost this type of a TBM

o The length of platform tunnel is likely to be approximately 420m to 450m long. This is considered too short to warrant the mobilisation costs involved in large diameter TBM tunnelling.

However there may be advantages in using a TBM under certain conditions.

o If the ground conditions are not suited to mining and a cut and cover approach is not possible.

o If the cumulative number of platform tunnels makes the overall tunnelling distance economic

o If this approach can be applied to more than one station

When the station location, depth and general ground conditions have been established the construction methodology will be evaluated on a case-by-case basis.

Construction of the platform tunnels by TBM method will require a means of launching or extracting the TBM from each end of the tunnel drive. This is likely to require a deep box at either end and across the entire width of the station.

A1.8.3.2 Mined Station Construction Mined approaches are the most common method of excavating short, large diameter tunnels and caverns required for mined stations. As discussed, large circular tunnels can be constructed using a sequenced approach, where the tunnel is broken down into a series of smaller excavation stages which form the completed and stable tunnel. Sequencing and the ultimate size of tunnel or cavern possible are dependent on the ground conditions and the depth of cover. In stable ground such as competent rock it may be possible to excavated platform tunnels for Type 1 and 2 stations in a single heading, however some form of sequencing is usually employed due to the physical constraints of the excavation and lining equipment. Examples of simple and more complex sequencing are shown below.



Heading and bench approach used for the North Downs Tunnel (HS1)

Multiple headings and bench approach used for Brisbane Airport Link

This type of construction generally requires a shotcrete lining with supplementary support provided by arches and or bolts depending on the ground type. The method requires exposure of the ground, therefore it may be unsuitable for use where groundwater inflow would:

o Destabilise the excavation

o Be too large to be removed from the tunnel

o Increase the risk of unacceptable ground movement

The effects of these increase with excavation size.

In recent years this method has been defined as New Austrian Tunnelling Method (NATM), or more recently Sprayed Concrete Lined Tunnel (SCL Tunnelling). NATM is a specific approach that relies on an observational approach to vary support design and placement. This approach may be suitable in some instances; however the term SCL will be used to cover mined tunnelling during this study.

A1.8.4 Construction Effects The creation of platform tunnels and caverns will potentially create surface settlement irrespective of construction method used. As the ground conditions become poorer the likelihood of significant settlement increases. The majority of the proposed station locations will be in “soft” ground, i.e. not rock. Therefore settlement will be a significant factor and risk for mined stations for HS2.



As the degree of settlement is related to the cross section of the tunnel through the “volume loss”, logically a larger tunnel creates more settlement than a smaller one; however SCL tunnels generally require consideration of a higher volume loss than an equivalent TBM tunnel as noted.

If multiple platform tunnels and associated turnouts are required for a mined station (for instance a terminal station where up to 10 platforms have been suggested) then there may be a significant cumulative settlement effect. On this basis, mined approaches for terminal stations are not to be considered as the primary working assumption for this stage of HS2.

A1.9 Tunnel Aerodynamic – A General Introduction

A1.9.1 Stage Gate 2 Report The Stage Gate 2 Report described a number of issues concerned with tunnelling, essentially cross-sectional issues, safety implications and aerodynamic effects.

At the end of Stage 2, it was considered that;

• The London or Birmingham tunnels would most likely be a pair of single-track tunnels at minimum cross-section;

• That aerodynamic considerations would govern tunnels on the line of route.

There were a number of aerodynamic issues, principally concerning the need for pressure comfort criteria appropriate to sealed trains in addition to the pressure requirements in the TSIs. Much more work was undertaken in this Stage 3 on these issues.

A1.9.2 Updated Analysis

A1.9.2.1 TSI requirements The pressure at any point on the train must not vary by more than 10kPa during passage of the train through the tunnel. Sealing of the train must not be taken into account – pressures are measured on the outside of the train. The TSI pressure limit is a safety criterion, and allows for failure of the train sealing system – for example, due to a broken window. The TSI limit must be met for all cases, including those where two trains meet in a two-track tunnel.

A1.9.2.2 Further requirements Further criteria to ensure passenger comfort have been agreed with HS2 as follows: no more than 0.5kPa pressure change in any 1 second period, and no more than 2.5kPa pressure change in any 10 second period. These criteria take into account sealing of the train – pressures are measured inside the sealed train. It is considered acceptable that pressure changes greater than those quoted occur for certain rare cases of two trains meeting in a two-track tunnel, provided that (a) the comfort criteria are never exceeded by more than 40%; and (b) the TSI requirement is always met; and (c) the comfort criteria are exceeded for no more than 5% of possible relative timings of the two trains entering the tunnel. The selected criteria are very similar to those used for HS1, but adapted to suit sealed trains.

A1.9.2.3 Analysis method Arup’s in-house 1D tunnel analysis program TunX was used to calculate the pressure changes inside and outside the train. The program has previously been validated against test and against published data.

A1.9.2.4 Input assumptions Key input data was taken as follows:

Input parameter Value Notes

Train cross-sectional area 11sqm Assume that HS2 reference train will be no larger than GB gauge

Line speed 320km/h or Lower speeds to be considered in



400km/h any long tunnel under London

Train sealing time-constant 10 sec Results are very sensitive to this

Train friction coefficient 0.003 To be confirmed

Train length 200m or 400m Worst case to be considered at each tunnel length

Other input data was derived from previous studies.

No account was taken of pressure relief shafts.

A1.9.2.5 Effect of tunnel diameter on line speed – long tunnel under London Pressure changes are strongly dependent on train speed and “blockage ratio” (ratio of train cross-sectional area to tunnel cross-sectional area). Smaller diameter tunnels may require lower line speed to meet the pressure criteria. There is therefore a trade-off between the cost of constructing a larger tunnel, versus increased journey time for a smaller tunnel. For a one-track tunnel of length 20km, the following results were obtained:

Internal diameter Speed to meet pressure criteria

Effect on journey time

7.0m 210km/h 2.0 mins

7.5m 240km/h 1.3 mins

8.0m 265km/h 0.8 mins

8.5m 290km/h 0.4 mins

9.0m 310km/h 0.1 mins

There is some sensitivity to tunnel length – speeds will have to reduce slightly if the tunnel is longer than the assumed 20km.

It was assumed that 10% of the internal cross-sectional area will be occupied by the track bed and other solid items.

The calculations exclude the effect of pressure relief shafts. If sufficient shafts can be provided, the speed for a given tunnel diameter may increase.

The effect on journey time has been calculated by taking the time required to pass through the 20km long tunnel at the given speed, compared to the time taken to pass through the same tunnel at a constant 320km/h. The quoted effect on journey time will therefore be exaggerated if it is not possible for the train to pass through at a constant 320km/h, for example if the portal is within the acceleration/deceleration distance of the London Station.

A1.9.2.6 Cross-sectional area for tunnels on Line of Route, 320km/h line speed Assuming a 320km/h line speed, the required free cross-sectional area of tunnels was calculated for a range of tunnel lengths as shown below. “Free cross sectional area” is the part of the cross sectional area that consists of air, measured with no trains present. One-track and two-track tunnels have been considered. For this purpose, a two-track tunnel is one in which both tracks share the same airspace; a tunnel in which the two tracks are separated by an airtight barrier would count for this purpose as two one-track tunnels. For two-track tunnels, we consider two trains running in opposite directions; a range of “time offsets” is considered, such that the second train enters the tunnel at the same time as the first train, or after a “time offset” delay. The required cross-sectional area is then determined for the worst-case time offset for each tunnel length. An equivalent internal diameter has also been calculated for use in costings, assuming that 10% of the total cross sectional area will be occupied by solid objects (such as the track bed). It is recognised that the two-track tunnel is unlikely to be circular; the “equivalent diameter” is used solely to tie in with the cost calculations.



Tunnel length Free Cross-sectional Area

(one track)

Equivalent diameter (one

track)

Free Cross-sectional Area

(two track)

Equivalent diameter (two

track)

0 – 0.4km 35sqm (*) 7.0m 72sqm (*) 10.0m

0.5 - 0.9km 50sqm 8.4m 95sqm 11.6m

1.0 – 1.8km 50sqm 8.4m 105sqm 12.2m

1.9 – 2.1km 55sqm 8.8m 105sqm 12.2m

2.25 – 2.75km 50sqm 8.4m 100sqm 12.2m

3.0 – 6.0km 50sqm 8.4m 95sqm 11.6m

(*) – assumed minimum size

The free cross-sectional area is the area occupied by air, i.e. the area of solid objects such as the track bed is excluded.

Results show that tunnels of length 400m or less may be designed to the minimum physical size to fit GC gauge (assumed to equate to free cross-sectional areas 34.6m2 and 72m2 respectively for one-track and two-track tunnels).

It has been assumed that no pressure relief shafts are provided. For tunnels where pressure relief shafts may be environmentally acceptable, we would recommend to explore the use of these to reduce the tunnel cross-sectional area as part of a value engineering exercise.

A1.9.2.7 Tunnel size for long tunnel under Birmingham Assuming that speed will be limited to 225km/h and that the tunnel would be approximately 10km long, the minimum size tunnel may be used, i.e. 7.0m internal diameter for one-track tunnel or 72sqm for a two-track tunnel.

A1.9.2.8 Sensitivities The train sealing time-constant has assumed to be 10 seconds. Results are very sensitive to this. The calculated tunnel areas will be sufficient if the actual sealing time-constant is at least 10 seconds. We recommend that measured data for the HS2 reference train should be requested from the train supplier.

The train skin friction coefficient has some influence on results. We have assumed that the friction coefficient is no higher than 0.003; this should be confirmed with the train supplier.

A1.9.2.9 Effect of 400km/h line speed The required tunnel areas for two-track tunnels and 400km/h line speed are given in the table below.

Tunnel length Free Cross Sectional Area (two track)

Equivalent Diameter

0 – 0.3km 95sqm 11.6m

0.4 - 0.8km 150sqm 14.6m

0.9 – 1.9km 162sqm 15.1m

2.0 – 6.0km 155sqm 14.8m

A1.9.2.10 Micro-pressure waves While aural comfort of passengers and crew is the main consideration for tunnel aerodynamics, the tunnels also need to be checked for micro-pressure waves (when the train enters one end of the tunnel, a booming noise may be emitted from the other end). It is not possible to calculate this effect directly for a proposed tunnel, but formulae are available for comparison with existing tunnels. The Bingo tunnel in Japan, where unacceptable booming was experienced, is used as a benchmark, and a sonic boom index is calculated



giving the expected sonic boom effect relative to that of the Bingo tunnel. An index of 0.5 or less may be taken to indicate acceptable performance. Results for North Downs tunnel on HS1, and some possible HS2 tunnels, are given in the table below.

Tunnel Length (km)

Tunnel area (sqm)

Train area (sqm)

Speed (km/h)

Factor Result

Bingo 8.9 63.4 200 1.0 Unacceptable

HS1 North Downs

3.2 104 9 300 0.53 Marginal

HS2 2-track 0.4

1.0

4.0

72

105

95

11

11

11

320

320

320

0.49

0.53

1.18

Marginal

Marginal

Unacceptable

HS2 1-track (Line of Route)

0.4

1.0

4.0

35

50

50

11

11

11

320

320

320

1.01

1.12

2.25

Unacceptable

Unacceptable

Unacceptable

HS2 1-track (London)

20 35 11 210 2.03 Unacceptable

Appendix B Tunnel Ventilation Working Paper


Page B1 Ove Arup & Partners Ltd15 December 2009

1B Tunnel Ventilation Working Paper B1.1 High Speed Rail 2 – Tunnel Ventilation Requirements

The successful design of a high-speed rail tunnel will involve the close integration of many disciplines, one of which is usually the Mechanical, Electrical and Public Health Engineering. MEP covers ventilation, fire main supply, drainage, plant room ventilation, staircase pressurisation, lighting, Radio re-broadcast, Supervisory Control and Data Acquisition (SCADA), Communications (CCTV, loudspeaker, signalling, traffic control, etc…) and electrical distribution (HV/LV transformers, switchgear).

The main mechanical systems needed in a high speed rail tunnel are ventilation, cooling, drainage and fire-fighting. The design of these systems, particularly for ventilation and cooling will be strongly influenced by the unique properties of each tunnel (namely length, cross section, gradient and cross-passage connections). Safety consideration and maximum access to equipment for maintenance during normal operations will also be key design criteria.

B1.2 Tunnel Ventilation

The functional design criteria for a ventilation system in rail tunnels are the following:

• Provide pressure relief for the train piston effect under normal operations – high speed trains will need special treatment.

• Control tunnel temperatures in period of extreme weather under normal operation.

• Control temperatures and supply outside air in the event that a train is forced to stop in the tunnel (congested operation).

• Control temperatures as well as smoke and hot gases in the event of a fire (emergency operation)

The operation of a rail tunnel can be divided into three modes: normal, congested and emergency. Each mode of operation may require ventilation for different reasons.

B1.3 Normal Operation

During normal operation, when the network is running to schedule, the ventilation of tunnels is usually not needed as the piston effect of train movements alone should induce sufficient ventilation. For high-speed trains, excessively high pressure pulses can cause aural discomfort in train passengers and sonic boom at the tunnel entry or exit portals. The aural comfort limit for passengers or mitigation of sonic boom is a subject of continued research that informs and improves the engineering design standards. The aural comfort standards are usually met either by an increased tunnel diameter or draught relief shafts at regular intervals, and the sonic boom is eliminated by special configuration of tunnel portals.

B1.4 Congested Operation

From a ventilation point of view, the system is said to be operating in a congested mode if a train is forced to make an unscheduled stop inside a tunnel. When this occurs the passive ventilation induced by the train piston effect stops. Mechanical ventilation of the tunnel may be necessary to supply fresh air to passengers and to control temperatures within the tunnel.

B1.5 Emergency Operation

In the event of a fire, the tunnel ventilation system must be capable of controlling smoke and heated gases to maintain a tenable environment for the safe escape of passengers. Specific tenability requirements on air temperatures, CO concentration, smoke obscuration levels, radiation heat flux, air velocities and fan noise are defined, as well as maximum start-



up times for individual fans and ventilation systems in the US standard NFPA 130: Standard for Fixed Guideway Transit and Passenger Rail Systems.

In general, longitudinal ventilation systems are used in commuter rail tunnels. Typically fans take air from ambient through a shaft at ground level (or the portal), push the smoke from a fire along the tunnel in one direction and then exhaust the air/smoke mixture via another vent shaft and deliver it to outside (or the other portal). The ventilation airflow speed in the tunnel must be of sufficient to prevent the back layering of smoke, called critical velocity. The system is designed to provide this airflow to create a tenable environment upstream of the fire.

The design fire load of a tunnel is related to the maximum amount of energy that could potentially be released from a fire inside it divided by the time duration. This gives a heat power value measured in MW, also know as the peak fire heat release rate (HRR). The peak HRR for the tunnel ventilation system is likely to be high due to the class of train carriages in service. For an electric train the design fire load generally allows for combustion of any flammable products in the train seating, undercarriage, body, as well as an allowance for passenger luggage. The fire scenario will then be selected based on the highest HRR.

A mechanical ventilation system is essential to ensure the comfort and safety of passengers aboard trains using the proposed commuter rail tunnels. Ventilation is needed to control air temperatures within the tunnels, provide outside air for respiration and control the flow of smoke in the event of a fire.

B1.6 Ventilation Shafts

The tunnel ventilation system relies on a number of shafts connecting the tunnel to the outside ambient. The construction of these shafts is very costly, can pose an engineering challenge in densely-populated cities, and raises popular opposition when built near residential or commercial property. It is thus important to minimize the number of ventilation shafts and optimize their size and functionality.

But tunnel ventilation shafts are not the only type of shafts connecting rail tunnels to the surface. Other intermediate shafts in high speed rail tunnels are often needed for other reasons and at different intervals; these can be for any of the following functions or combination of:

(I) Intervention point for emergency services such as London Fire and Emergency Planning Authority (LFEPA), ambulance services, etc

(E) Emergency evacuation for passengers

(FV) Forced ventilation: mechanical ventilation for train heat removal or fire smoke control

(DR) Draught relief: natural ventilation to relieve piston effect pressure and airflows

A holistic design would seek to combine and optimise the construction of shafts to minimise cost and maximise functional sharing. The successful implementation of this depends on the engineering standards that govern the required intervals, but our experience indicates that there is usually enough flexibility that can be exploited creatively.

In a high-speed rail tunnel, there is no unique design solution. From an aerodynamic point of view, for a given tunnel length and train speed, there is usually a choice between a smaller tunnel diameter and regular DR shafts, or a larger tunnel diameter without DR shafts; a cost benefit analysis often drives the ultimate solution. The DR function is very important, due to the compressibility behaviour of air moving at high speed and the associated noise effects. For a given train speed and blockage ratio (ratio of train cross sectional area to tunnel cross sectional area), there is a need for regular DR shafts to relieve the pressure waves so as to avoid passenger aural discomfort. The other benefit of a DR shaft is to reduce the traction power of the train, as part of the column of moving air ahead of the train now leaves the system, which reduces the aerodynamic drag.



Another method of providing pressure relief in twin tube arrangements is from one tunnel to the other via pressure relief ducts, as used in the Channel Tunnel. This has the additional benefit of reducing the traction power of the train, since the aerodynamic resistance of moving the column of air ahead of the train is reduced dramatically. This method is particularly suited to long rail tunnels or when surface penetration is impossible.

Since high-speed trains are capable of inducing localised air velocities up to 50 m/s and air pressures exceeding 10 kPa, there is a need for accurately predicting and allowing for both normal and design limit aerodynamic loading of all fixed equipment and rolling stock in the tunnel. However it is also necessary to consider how to provide satisfactory ventilation throughout the whole tunnel in view of such operating conditions. The main configuration of the tunnel, whether two single-track tubes interconnected with cross-passage doors at regular intervals or one double-track tube with a relatively large crown will work in favour of some ventilation system designs and against others.

Other issues to consider are that the ventilation fans would have to withstand the full pressure of the piston effect of the shuttles at high-speed. There also has to be a guaranteed “safe haven” for passengers in the event of a fire emergency or during detraining in the tunnel.

B1.7 Spatial Requirements

Tunnel ventilation plant generally requires relatively large amount of plant and distribution space. This typically consists of:

• Plant room or building (underground cavern or above ground structure) including space for the equipment, lay-down areas for maintenance work, access for maintenance and replacement

• Shafts with louvered inlets and outlets for supply and exhaust air

• Air distribution ducts (from plant to and possibly along tunnels)

• Additional routes for maintenance and removal access of necessary

B1.8 Proposed Work Plan

For the High Speed 2 project, a feasibility study is required to investigate the various designs of tunnel ventilation systems and the requirement for pressure draught relief (DR) or mechanical forced ventilation (FV) shafts. It should also seek to combine these with intermediate shafts with other functions such as Intervention of emergency service personnel (I) or emergency evacuation of passengers (E).

The location of these shafts, their number and size will have to be confirmed in collaboration with tunnel engineers, as well as architects, environmental engineers and real estate specialists.

Furthermore the proposed ventilation system must consider adequate maintenance and access provisions to enable the operators to maintain the systems cost-effectively. This is equally true for all the MEP systems which must be designed in close coordination.

Appendix C Geotechnical Considerations


Page C1 Ove Arup & Partners LtdDraft 1 12 November 2009

1C Geotechnical Considerations


Page C1 Ove Arup & Partners Ltd15 December 2009

MATERIALS AND GROUND CONDITIONS ALONG ROUTE 3

Geological Name

Material Type

Geotechnical Issues Suitabilility for re use in earthworks

Location within Scheme

Made Ground Very variable, typically gravelly clay or sand with gravel

Variability and unpredictable engineering properties. Potential to be non inert and requiring a waste management license to move.

20 - 30% unsuitable for re use in earthworks. But potential re usable in environmental bunds. Also may be possible to process for use in earthworks but at extra cost. 2% will require special disposal or expensive treatment

Mainly at the London and Birmingham ends of the scheme, where Brownfield land will be traversed. Very locally elsewhere

Alluvium Soft to stiff silty Clay. Peat and soft organic Clay

Some / Much of the alluvial material present will be unsuitable formation for the earthworks formation. Mitigation measures required including either dig out and replace below formation or special foundations.

Much of if not all excavated material will be unsuitable for re use in earthworks. But most will be potential re usable in environmental bunds.

Present across all valley bottoms traversed by the scheme

Head Deposit (and periglacially disturbed material)

Firm to Stiff Gravelly Clay

Variability and in places poor engineering properties.

Some material will be unsuitable for re use in earthworks. But most will be potential re usable in environmental bunds.

Potentially present as a discontinuous thin layer overlying undisturbed and insitu material, beneath the whole of the scheme, particularly north of the Chiltern Hills.

River Terrace Deposits

Loose to medium dense Sand and Gravel, occasionally clayey

None All Reusable in Earthworks though may require some processing to provide material to earthworks spec

Occurs sporadically within the valley bottoms and sides of the larger valleys eg the River Avon in Warwickshire and the River Great Ouse in Buckinghamshire

Glacial Till Soft to very stiff sandy gravelly Clay

Variable material 2 - 5% probably unsuitable for re use in earthworks due to low strength and high moisture content (particularly when mixed with water bearing sand and gravel). However recovery assumes good construction practice with well drained excavations and no wet weather working as material is susceptible to deterioration when wet.

North of the Chiltern Hills, particularly in Warwickshire and Buckinghamshire

Glacial; Sand and Gravel

Mainly loose to medium dense Sand with Gravel, can be silty

Can contain groundwater, which in places may be troublesome for earthworks slope stability

All Reusable in Earthworks though may require some processing to provide material to earthworks spec

North of the Chiltern Hills, particularly in Warwickshire and Buckinghamshire



Glaciolacustrine Deposits

Interbedded soft to stiff Clays Silts and Medium Dense Sands

Can contain groundwater, which in places may be troublesome for earthworks slope stability

5% probably unsuitable for re use due to low strength and high moisture content

Locally in parts of Warwickshire, adjacent to the River Tame

Fluvial Sands and Gravels of Mid Pleistocene age, deposited by ancestral River Thames

Medium dense to dense Sand and Gravel


The lower parts of the Chiltern Hills

Clay with Flints Firm to stiff Red Brown silty Clay with large Flint Nodules, contains masses of palaeogene sand.

Variable material. Very irregular and unpredictable contact with the underlying Upper Cretaceous Chalk Group

5% probably unsuitable for re use due to low strength and high moisture content

The higher parts of the Chiltern Hills

Palaeogene London Clay Formation

Very stiff Grey Clay, weathering to a firm brown Clay

High Sulphates in the weathered zone. Vulnerable to shrinkage and swelling

5% probably unsuitable for re use due to low strength and high moisture content in near surface weathered zone

London

Palaeogene Lambeth Group

Stiff mottled Clay.Some Dense sand and silt lenses

Potential for some material to have low strength and high moisture content

5% probably usuitable for re use due to low strength and high moisture content in near surface zone

London

Upper Cretceous Chalk Group - Upper and middle Chalk

Weak, low to medium density, pure limestone, with occasional Bands of High Density limestone

Suspectable to natural solution. Local Mine workings


Chiltern Hills

Upper Cretceous Chalk Group -Lower Chalk

Weak slightly clayey limestone passing downwards into very stiff grey very calcareous Clay

None but careful handling required


north slope of the Chiltern Hills

Lower Cretaceous Upper Greensand Formation

Very dense Green sand and moderately weak sandstone (only 1-2m thick)

None but careful handling required

All Reusable in Earthworks though may require some processing to provide material to earthworks spec (if present)

South east of Aylesbury

Lower Cretaceous Gault Formation - Upper Gault

Stiff Grey calcareous Clay


South east of Aylesbury

Lower Cretaceous Gault Formation - Lower Gault

Stiff Dark Grey silty Clay

Possible vulnerability to shrinkage and swelling


Aylesbury



Upper Jurassic Purbeck and Portland Formations

Moderately weak to Moderately strong Limestone and weak Mudstone weathering to Stiff Clay


Aylesbury

Upper Jurassic Kimmeridge Clay Formation

Very Dense Silt, Stiff Light Grey calcareous Clay, weak to moderately weak dark grey/black bituminous Mudstone

High Sulphates in the weathered zone


Aylesbury

Upper Jurassic Ampthill Clay Formation

Stiff Dark Grey silty Clay



North West of Aylesbury

Upper Jurassic West Wallton Formation

Stiff Grey calcareous Clay



North West of Aylesbury

Upper Jurassic Oxford Clay Formation

Stiff to very stiff Dark Grey silty Clay in places weak Mudstone



Between Aylesbury and Chetwode (north east of Bicester)

Middle Jurassic Great Oolite Group. Cornbrash Formation, Forest Marble Formation, White Limestone Formation

Moderately Strong Limestone and weak Mudstone weathering to Stiff Clay

None All Reusable in Earthworks though may require some processing to provide material to earthworks spec.10 to 20% Rock

Between Chetwode (north east of Bicester) and Brackley

Middle Jurassic Great Oolite Group. Rutland Formation

Dense to very dense Sand, Stiff to very Stiif Clay and Moderately weak to moderately stongLimestone


Brackley

Middle Jurassic Inferior Oolite Group. Northampton Sand Formation

Moderately weak to moderately strong Ferruginous Limestone

None All Reusable in Earthworks though may require some processing to provide material to earthworks spec. 5% Rock

Thorpe Mandeville area (north west of Brackley)

Lower Jurassic Lias Group. Whitby Mudstone Formation (Upper Lias)

Firm to stiff Dark Grey silty Clay

Possible slope instability problems. Slack cut slope angles required. High Sulphates in the weathered zone


Thorpe Mandeville area (north west of Brackley)



Lower Jurassic Lias Group. Marlstone Rock Formation Dyrham Siltstone Formation (Middle Lias)

Moderately Strong Ferruginous Limestone, very dense Silts and stiff to very stiff Silty Clays

None All Reusable in Earthworks though may require some processing to provide material to earthworks spec. 20% Rock

Chipping Warden (North east of Banbury)

Lower Jurassic Lias Group Lower Lias Clay Formation

Stiff to very stiff Grey silty Clay in places weak silty Mudstone


All Reusable in Earthworks though may require some processing to provide material to earthworks spec. 20% Rock

Aston le Walls (North east of Banbury) to Southam

Lower Jurassic Lias Group Blue Lias Clay Formation

Interbedded Weak Mudstone weathering to Stiff Clay and Moderately strong Limestone


Southam

Triassic Penarth Group Lilstock Formation. Westbury Formation

Moderately Strong Limestone and Firm to stiff Dark Grey Clay

Possible slope instability problems on the Westbury Formation. Slack cut slope angles required. High Sulphates in the weathered zone

40% unsuitable for re use in Earthworks (Westbury Formation)

North West of Southam

Triassic Mercia Mudstone Group

Weak Red brown silty Mudstone weathering to a stiff silty Clay


Offchurch (East of Leamington Spa) and east of Solihull

Triassic Sherwood Sandsone Group

Dense Sand and Weak Red Brown Sandstone

None All Reusable in Earthworks though some with care given the single sized nature of the materials in places

Lichfield area

Permian Hopwas Breccia

Dense to very dense Sand and Gravel


Roundhill Wood south of Lichfield

Permian Kenilworth Sandstone Formation

Moderately weak to moderately strong Sandstone and Weak red brown silty Mudstone weathering to a stiff silty Clay


Stoneleigh

Upper Carboniferous Tile Hill Mudstone Formation

Weak Red brown silty Mudstone weathering to a stiff silty Clay


West of Tile Hill



Upper Carboniferous Salop Formation

Weak Red brown silty Mudstone weathering to a stiff silty Clay and Moderately weak to moderately strong Sandstone


Roundhill Wood south of Lichfield

1/ EA may require reuse only within host strata subcrop

2/ Contaminated land issues/archaeology etc not included here

3/ Excludes tunnel spoil which may be possible to reuse following 'treatment'

4/ Comments on use in earthworks does not take into account slope stability issues which will vary with each material type.

5/ Some materials may very dry and strong and may require wetting for optimum re use

Appendix D Structures Issues


Page D1 Ove Arup & Partners Ltd15 December 2009

1D Structures Issues D1.1 The Need for Structures

To cross valleys and to raise the alignment over crossing routes, there is a need for the railway to be carried on viaduct. In some places, the elevated lengths could be 5km or more. In general, the plan curvatures will be slight but there is a specific need in the West Midlands for an elevated delta junction. This might require a plan radius of about 900m. At this stage it is assumed all standard structures carry two tracks.

D1.2 Precedents

There are now significant lengths of high-speed railways in Japan, France, Spain, Germany, South Korea and Taiwan. Good records of structures for these railways are the papers of the IABSE Symposium in Antwerp 2003 "Structures for High-Speed Railway Transportation." This is now 6 years old and a search is needed to find reports of more recent structures.

Arup has considerable detailed experience from its work on HS1, the high-speed railway from London to the Channel Tunnel. It was part of the Rail Link Engineering team which designed and project managed all aspects of the railway, from 1996 to 2007.

D1.3 Aspirations

D1.3.1 Rapid, cheap construction of repeating spans On very large civil engineering projects there are opportunities to achieve construction speeds and economies which are beyond normal practice due to standardisation and investment in special equipment, typically with whole spans being lifted in one to create viaducts. The current exercise assumes that the project will be planned to get advantage from these economies of scale.

D1.3.2 Minimise visual bulk It is desirable for the railway to sit comfortably in the landscape, in a visual sense. More specifically the planning and approval processes make up a large part of the overall project programme and a good looking design will speed up these processes.

In flatter landscapes the clearance beneath the viaducts will be governed by the crossing routes and will usually be only about 6m. To fit easily into existing patterns of land-use the repeating spans will probably be in the range 40m to 50m. With a slim pier in the central reserve a 50m span alignment can cross a motorway with a large skew. These spans with the 6m clearance could look very squat and heavy. The part-though option discussed below significantly reduces the overall visual depth.

D1.3.3 Simultaneous use by freight and passengers The high-speed railway is principally for passengers but, as part of the overall optimisation of the operation of the UK railway network there may be occasions when it will be used for freight. If a heavy freight train is present on one track of a two track structure then it may induce deformations which would cause a high speed train on the adjacent track to exceed its vertical dynamic design limits.

This topic is mentioned here because one of the structural options being considered will provide significantly greater restrictions in this respect than other options, and the better solution is probably available without extra cost. The parameter used to compare designs is the weight of freight train in kN/m which can simultaneously use the structure which has been designed for passenger use without restricting the operational speed for passengers. Note that this relates only to dynamic matters because it is normal practice to design passenger-only structures for the full static weight of freight trains.



D1.4 Choices

D1.4.1 Span length It is not necessary for all viaducts to have the same span lengths but it is likely that construction equipment will be passed from site to site, and the size of this equipment will be driven by the largest span. As stated above it is likely that the spans will be in the range 40m to 50m.

D1.4.2 Steel or concrete In the UK in recent years most highway and railway bridges have been built in steel/concrete composite construction, with a concrete deck on steel girders. Loosely such bridges are described as steel bridges, and steel bridges have been more economic generally. Most of the bridges on HS1 were built in concrete. This is because HS1 follows a new alignment and is subject to strict noise limits where it crosses areas with no precedent for noisy activity.

In general steel bridges are significantly noisier than concrete bridges. However steel bridges can be designed to meet specific noise limits. There is limited experience in this field, and it requires very heavy use of computers to map out hundreds of dynamic modes. Studies were made during the design of HS1 and the last viaduct, for Rainham Creek, was designed in steel. To meet the strict limits it is necessary to use direct load paths, with a structural web provided under the centre of each track. Steel web plates need to be thicker than usual, with many stiffeners. Box-girders are avoided because they tend to have wide, booming flanges. Together this leads to structures with plate girders at close centres. Such structures can only accept a limited degree of horizontal curvature.

It is likely that the cost advantage of steel will be lost on a very large project. The basic material costs for concrete solutions are probably less and with the appropriate initial investment and factory-like on-site precasting it should be possible to drive the costs down towards these base values.

D1.4.3 Continuous structure or continuous rail There are different practices in the provision of rail expansion joints for high-speed railways. HS1 was based on French practice which is very restrictive. Joints are only provided in pairs which have to be about 40m apart. These joints must be supported on a 40m long "inert span" which is anchored in space. The Medway Viaduct on HS1 is 1250m long. It has two inert spans, and the four columns which support the two spans have to be much thicker than the standard columns.

In general rail joints are expensive and they require maintenance. It is possible to design viaducts with no rail joints provided there are movement joints in the supporting structure at a spacing of not more than 80m. With careful design and additional analytical checks this spacing can be increased to 90m. These limits relate to ballasted track. For slab-track the limits are significantly less and they depend on details of the rail fixing system.

Many viaducts for high speed railways have been built using the push-launch construction method in which each span is cast behind one abutment, and the growing deck structure is pushed forwards every Monday morning. This is a very efficient method of construction because the casting cell operates like a factory and provides a safe environment. However it results in a continuous structure, and so it needs rail joints. The only long, repeating span viaduct on HS1 is Thurrock Viaduct. It was push-launched but this decision was driven by the specific need for it to be threaded through a tight window which takes it over and under the two carriageways of the M25.

It is anticipated that the viaducts for HS2 will be built with continuous rail, unless the rail is more than about 35m above ground level when a continuous structure may be used.

D1.4.4 Joints at piers or half-joints If the continuous rail solution is chosen then it has to be decided where the structure joints are placed in the span. Usually joints are place over piers. The piers have to be wider to



receive two sets of bearings. Under load there is a significant differential rotation across the joint which is the principal generator of vertical accelerations in the carriages of high-speed trains. To limit the rotations the structural depth has to be increased and, finally, the simply-supported span configuration is inefficient structurally because it only uses the moment capacity of the beam once per span. Only a light coexisting freight train would be possible with this configuration.

The alternative is to provide a half-joint near the fifth points of each span. The rotations across the joint are very small. The moment capacity of the beam is used twice in each span, over the pier and again at midspan. For both reasons it can have a much reduced structural depth. However half-joints have a bad reputation and they have been banned for new bridges by the UK Highways Agency. The problems relate partly to the use of joints in general, where the issues are completely different for highways, and mostly they relate to maintenance difficulties. Typical half joints for highways are in smaller decks and have usually been provided without a space allocation for the jacks needed to replace the bearings. And inspection is very difficult. For the larger scale structures proposed for the high-speed railway it is anticipated that a half-joint can be designed which overcomes these failings.

D1.4.5 Ballast or slab-track In the past this has been a matter of culture. France believed in ballasted track and all its benefits, and Germany believed in slab-track, and a different set of benefits. Recently Germany has been using ballasted track both at grade and on structures. Perhaps the debate has passed.

Ballasted track is heavier than slab-track but this may not be an issue. Erection methods for whole span precasting usually require the next span to be tracked over the previous spans. It is likely that this will impose loads similar to the service loading of a ballasted track.

Slab-track is shallower than ballasted track. Again this may not be an issue. In the structural solution adopted below a "part-through" configuration has been used with the top flanges of the structural section placed outboard of the track. In these cases the overall visual depth is not increased by the depth of the track system.

D1.4.6 Below-track or part-through sections Almost all long viaducts for high-speed railways have been built with the structure below the track. This results in a large visual depth.

The UK has differed from other countries in having a specific requirement for all heavy railways called the "robust kerb" which is a concrete kerb alongside the track to contain a derailed train. When HS1 was designed the robust kerb was at the level of the top of the rail with a further 100mm allowance for overfilling of the ballast. Railtrack's standard GC\RC5510 then increased this to 300mm above the top of the rail with 50mm for overfilling. In December 2008 this standard was withdrawn and replaced with GC\RT5112 which removes the specific requirements but it retains the general requirement for derailed trains to be contained. We are choosing to retain the requirements in GC\RC5510 to provide this containment. Hence we start with a need for structure which, with ballast, is about 1200mm above the underside of the track envelope.



Section of part-through concrete deck

A part-through concrete section is shown in Figure 1 for a 50m span. The top of the structural depth is the top of the top flanges which are 300mm below the maintenance walkway, at the level of the robust kerb. The 300mm provides space for signalling cables etc, and is sufficient for one or two external prestressing cables above the top flange. The provision of 2.1m headroom for maintenance personnel determines the depth of the concrete box-girder below the track. This results in a structural depth below rail level of 3.5m. Note that with this configuration a reduction in span will not result in a reduction in structural depth.

Section through a steel/concrete composite deck

Traditionally the span/depth ratio for high speed railways has been about 14. With explicit transient dynamic modelling, and using continuous or half-jointed spans, this factor can be increased but it is representative of past practice.

Figure 2 shows the section of a steel part-through scheme which has been sketched for HS2, with spans of 50m Note that for construction purposes there is a minimum depth of steel girder which is practical, and this drives the overall structure depth and provides a section capable of at least about 50m span, whatever span is required.



A span of Arsta Viaduct

Section of Arsta Viaduct

Arup has some experience with part-through solutions. Firstly with Arsta Viaduct (Figures 3 & 4) in Stockholm. This is an architecturally driven solution with varying depth spans with curved sections. It is 820m long with repeating spans of 78m. For completeness Crossgate Viaduct in South Shields on the Tyne & Wear Metro is also mentioned, but it was for a much shorter span.



D1.5 Provisional conclusions

Provisionally it is assumed that the viaducts will have ballasted track, continuous rails and spans of up to 50m. It is also likely that a concrete part-through deck will be used, with half-joints, as shown in section in Figure 1. The structural depth measured from rail level to soffit is 3.5m. Figure 5 shows elevations of this proposal. The upper elevation shows it crossing a valley. The lower elevation shows it at a low level with a clearance of about 6m which is just sufficient to cross a road or a railway. Quantities have been calculated and costed for this proposal.

Elevation of repeating concrete spans of 50m

Figure 5 also shows the proposed section through the columns. This is quite thick when viewed in elevation in order to transfer longitudinal loads to the foundations. It is similar to the section used for Medway Viaduct on HS1. Because the column is monolithic with the deck there is no need to provide space for bearings and the column can be quite narrow across the line of the bridge. It can taper towards the edges of the bridge. Together these characteristics reduce the visual width of the columns in skew views. A special slimmer column would be used in a central reserve when the railway passes skew over a motorway.

A cut down version of the deck section without the concrete box-girder would have a structural depth (rail level to soffit) of about 1.3m and would span about 20m.

Appendix E Alignment Issues - Old Oak to Ruislip


Page E1 Ove Arup & Partners Ltd15 December 2009

1E Alignment Issues – Old Oak to Ruislip E1.1 Structures above or spanning over the proposed track alignment

The following table details the existing structures which span over the proposed track alignment.

Notes

• Chainage based on drawings HS2-ARP-04-DR-RW-01001 to 01007, and HS2-ARP-07-DR-RW-03001 to 03002.

• It is not possible to definitively assess the clear width under the bridges from the existing information available. Further information or site surveys will be required.

• The width of the existing corridor has been assessed as the existing clear area that could be utilised without significant works. This is therefore the space between existing obstacles or boundaries such as buildings, tops of embankments, bottoms of cuttings, fence lines or rail tracks. Assessment based on visual observation of aerial photographs. The legal ownership of land has not been assessed, nor has the feasibility of constructing the necessary rail infrastructure in the available space.

Latitude Longitude Chainage (m)

Apparent width of corridor (m)

Description Link

51.528394 -0.283176 11,550 13.5 Pedestrian foot bridge.

Image

51.528619 -0.28425 11,620 13.5 Connection between Western Avenue and Lakeside Drive.

Image

51.528872 -0.285544 11,740 12.8 Rail bridge Image 51.530296 -0.292618 12,230 15.4 A406 crossing to the

north of Hanger Lane underground station.

Image

51.530649 -0.294764 12,390 10.7 Hanger Lane (west) Image 51.546831 -0.36271 17,440 10.1 Pedestrian foot

bridge. Image

51.548191 -0.368011 17,840 9.2 Mandeville Road (A312)

Image

51.549647 -0.373804 18,270 8.4 Eastcote Lane Image

51.565969 -0.426159 3,010 Pedestrian foot bridge? Appears to lead to the Ruislip Depot so usage uncertain.

Image

51.569162 -0.435733 3,760 Pedestrian foot bridge at West Ruislip Station

Image

51.569811 -0.437702 3,930 Ickenham Road at West Ruislip Station

Image



E1.2 Rail Bridges or Viaducts

The following table details the existing structures which the new track alignment will utilise to cross roads, canals, rivers and other railways. As discussed above these bridges will need to be assessed, and supplemented where necessary due to insufficient existing load capacity or size.

Latitude Longitude Chainage at centre (m)

Relevant width of existing bridge (m)

Length (m) Description Link

51.531176 -0.298473 12,650 20.4 13.0 Bridge over West Gate. Existing bridge area used by underground lines not included in measurement.

Image

51.531821 -0.30288 12,950 8.2 120.0 Bridge over River Brent. Dedicated bridge taking two tracks. Additional bridge adjacent for underground tracks.

Image

51.532852 -0.307861 13,320 7.4 24.0 Bridge over Alperton Lane (B456). Existing bridge area used by underground lines not included in measurement.

Image

51.533287 -0.309559 13,440 7.9 20.2 Bridge over disused rail route. Existing bridge area used by underground lines not included in measurement.

Image

51.534513 -0.314376 13,810 7.5 3.0 Culvert under railway. Existing bridge area used by underground lines not included in measurement.

Image

51.53584 -0.31954 14,200 7.4 13.2 Bridge over Bideford Avenue (B456). Existing bridge area used by underground lines not included in measurement.

Image

51.537007 -0.324225 13,550 8.0 22.2 Bridge over Horsenden Lane South. Existing bridge area used by underground lines not included in measurement.

Image

51.541081 -0.339974 15,720 6.6 23.8 Bridge over Lyon Way. Existing bridge area used by underground lines

Image



Notes

• Chainage based on drawings HS2-ARP-04-DR-RW-01001 to 01007, and HS2-ARP-07-DR-RW-03001 to 03002

not included in measurement.

51.54193 -0.343238 15,980 11.7 21.8 Bridge over Greenford Road (A4127). Image

51.542609 -0.345864 16,180 16.1 18.3 Bridge over Oldfield Lane North. Image

51.545141 -0.356092 16,950 7.6 34.0 Bridge over Grand Union Canal Image

51.553188 -0.387201 19,260 6.3 32.6 Bridge over rail branch off. Full width measured.

Image 51.556723 -0.39807 810 5.1 13.7 Bridge over Long

Drive by South Ruislip Station. Available width after Chilterns lines have been moved to the southern extent measured. Image

51.559739 -0.407192 1,530 7.4 13.4 Bridge over Bridgewater Road. Available width after Chilterns lines have been moved to the southern extent measured. Image

51.561562 -0.412672 2,000 8.0 37.9 Bridge over West End Road. Available width after Chilterns lines have been moved to the southern extent measured. Image

51.56762 -0.431142 3,380 4.4 11.4 Bridge over Piccadilly and Metropolitan Lines to Uxbridge. Assumed that only one of the existing track bridges is available for reuse by the HS lines. Image



E1.3 Corridor widening

The following table details the available corridor width along the surface alignment from the envisaged tunnel portal location at the eastern end of the alignment to the Hillingdon Waste Transfer Station.

Notes

• Chainage based on drawings HS

Start of section End of section

Latitude Longitude Available width (m)

Latitude Longitude Width (m)

Length (m)

Average additional width required if a 25m wide HS corridor is assumed. (m)

51.528227 -0.282129 15.5 51.528394 -0.283176 13.5 75 10.5 51.528394 -0.283176 13.5 51.528619 -0.28425 13.5 78 11.5 51.528619 -0.28425 13.5 51.528884 -0.285561 12.8 95 11.85 51.528884 -0.285561 12.8 51.529592 -0.289036 12.5 253 12.35 51.529592 -0.289036 12.5 51.530296 -0.292618 15.4 260 11.05 51.530296 -0.292618 15.4 51.530649 -0.294764 10.7 154 11.95 51.530649 -0.294764 10.7 51.531176 -0.298473 10.9 263 14.2 51.531176 -0.298473 10.9 51.531821 -0.30288 13.3 313 12.9 51.531998 -0.303865 16.4 51.532852 -0.307861 10.7 292 11.45 51.532852 -0.307861 14 51.533287 -0.309559 16.4 127 9.8 51.533287 -0.309559 11.7 51.534513 -0.314376 8.8 360 14.75 51.534513 -0.314376 9.9 51.53584 -0.31954 11.3 386 14.4 51.53584 -0.31954 11.5 51.537007 -0.324225 10.9 349 13.8 51.537007 -0.324225 10.9 51.538204 -0.328823 13.3 345 12.9 51.538204 -0.328823 13.3 51.539023 -0.331964 19.3 236 8.7 51.539023 -0.331964 19.3 51.541081 -0.339971 12.8 599 8.95 51.541081 -0.339971 12.8 51.54193 -0.343238 20.5 245 8.35 51.54193 -0.343238 25.8 51.542609 -0.345864 22.3 197 0.95 51.542609 -0.345864 22.3 51.544008 -0.35144 18.2 416 4.75 51.544008 -0.35144 14.6 51.545141 -0.356092 10.3 345 12.55 51.545262 -0.356545 11.5 51.546831 -0.36271 10.1 461 14.2 51.546831 -0.36271 10.1 51.548191 -0.368011 9.2 397 15.35 51.548191 -0.368011 9.9 51.549647 -0.373804 8.4 432 15.85 51.549647 -0.373804 8.4 51.551371 -0.380563 9.6 505 16 51.551371 -0.380563 9.6 51.553188 -0.387201 10.4 501 15 51.553188 -0.387201 12.4 51.555613 -0.394516 23 573 7.3 51.555613 -0.394516 13.4 51.556056 -0.395858 12.8 105 11.9



Notes

• The width of the existing corridor has been assessed as the existing clear area that could be utilised without significant works. This is therefore the space between existing obstacles or boundaries such as buildings, tops of embankments, bottoms of cuttings, fence lines or rail tracks. Assessment based on visual observation of aerial photographs. The legal ownership of land has not been assessed, nor has the feasibility of constructing the necessary rail infrastructure in the available space.

• The section between the spur into Hillingdon Waste Transfer Station and West Ruislip

Station has not been assessed in this table. This is as along this length of line, the existing Chiltern Lines will need to be relocated to the southern extent of the rail corridor to maximise the space available for the HS lines. This exercise will require the track alignment to be modelled to ensure satisfactory operating speeds are achieved. See the 1:1250 scale drawings of this area for further details of how the track alignments are envisaged to be modified.

Appendix F

Costs and Risk Register


Page F1 Ove Arup & Partners Ltd15 December 2009









Appendix G

Drawing List


Page G1 Ove Arup & Partners Ltd15 December 2009

Drawing Number Description Scale

Euston Station HS2-ARP-03-DR-BL-30221 Euston Station, Option 302, HS2 @ +16.50 Classic Lines @ +35.00 1:2000@A1

Euston Station HS2-ARP-03-DR-BL-30231 Euston Station, Option 302, Plan and Sections 1:1000@A1

Euston Station HS2-ARP-03-DR-BL-30251 Euston Station, Option 302, Construction Plan 1:2000@A1

Euston Station HS2-ARP-03-DR-BL-30323 Euston Station, Option 303 , Concourse Level 1:2000@A1

Euston Station HS2-ARP-03-DR-BL-30324 Euston Station, Option 303 , Platform Level 1:2000@A1

Euston Station HS2-ARP-03-DR-BL-30334 Euston Station, Option 303 , Section AA and BB 1:1000@A1

Euston Station HS2-ARP-03-DR-BL-30333 Euston Station, Option 303 , Close up Plan 1:1000@A1

Euston Station HS2-ARP-03-DR-BL-30342 Euston Station, Option 303, Construction Phasing N/A

Euston Station HS2-ARP-03-DR-RW-30343 Track Alignment - Road 2 and 8 1:2000@A1

Euston Station HS2-ARP-03-DR-RW-30344 Track Alignment - Road 3 and 9 1:2000@A1

Euston Station HS2-ARP-03-DR-BL-30304 Euston Station, Circulation Diagram N/A

Euston Station HS2-ARP-03-DR-BL-30351 Euston Station, option 303, Construction Plan 1:2000@A1

Euston Station HS2-ARP-03-DR-BL-30352 Euston Station, option 303, Relocation Plan 1:2000@A1

King's Cross Land HS2-ARP-03-DR-BL-33121 Kings Cross Land, Option 331, HS2 @ -35.00 Below Ground (Approx) 1:1000@A1

King's Cross Land HS2-ARP-03-DR-BL-33131 Kings Cross Land, Option 331, HS2 @ -35.00 Below Ground (Approx) 1:2500@A1

Lond

on S

tatio

ns

King's Cross Land HS2-ARP-03-DR-BL-33151 Kings Cross Land, Option 331, Construction site 1:2500@A1

Drawing Number Description Scale Detailed drawings of London Approach HS2-ARP-04-DR-RW-42110

Alignment from Euston Station to West Ruislip - Plans - Sheet 1 of 8

1:1250@A0 (long plot)

Detailed drawings of London Approach HS2-ARP-04-DR-RW-42111


















Lond

on A

ppro

ache

s






Drawing Number Description Scale Route 3 HS2-ARP-07-DR-RW-03100 Route 3 Key Plan 1:250000@A1

Route 3 HS2-ARP-07-DR-RW-03101 Route 3 Plan and Profile sheet 1 of 34 1:10000@A1

































Line

of R

oute

3





West Midlands HS2-ARP-05-DR-RW-14102 Water Orton Corridor Fazerley St/Warwick Wharf Station Plan Profile Sheet 1 of 7 1:1250 @ A0







West Midlands HS2-ARP-05-DR-RW-14014 Water Orton Corridor Warwick Wharf Station Plan Profile Sheet 5 of 7 1:1250 @ A0



West Midlands HS2-ARP-05-DR-RW-00012 Birmingham International Corridor Plan Profile Sheet 1 of 9 1:1250 @ A0









West Midlands HS2-ARP-05-DR-RW-0053 Birmingham International Corridor Fazerley Street Station Plan Profile Sheet 1 of 3 1:1250 @ A0



West Midlands HS2-ARP-05-DR-RW-0056 Birmingham International Corridor Warwick Wharf Station Plan Profile Sheet 1 of 3 1:1250 @ A0



Outer Delta Junction HS2-ARP-DR-RW-00001

Birmingham International Delta Junction Plan and Profiles Not to Scale

Outer Delta Junction HS2-ARP-DR-RW-00003

Water Orton Outer Delta Junction Plan and Profiles Not to Scale

Highway Modifications HS2-ARP-05-DR-CX-00001

Birmingham Interchange Station Area General Arrangement 1:5000 @ A0

Highway Modifications HS2-ARP-05-DR-CX-00002 Heartland Roundabout Highway Improvements 1:2500 @ A1 Birmingham Depot HS2-ARP-05-DR-RE-84901

Washwood Heath Potential Depot Site Conceptual Layout option 1 1:2000 @ A0

Birmingham Depot HS2-ARP-05-DR-RE-84902 Birmingham Depot Washwood Heath Option 2 1:2000 @ A0

Birm

ingh

am A

ppro

ache

s

Birmingham Depot HS2-ARP-05-DR-RE-84903 Birmingham Depot Washwood Heath Option 3 1:2000 @ A0



Drawing Number Description Scale Birmingham Station HS2-ARP-09-DR-BL-90505 Fazeley Street Terminus - 905 1:1000 @ A1

Birmingham Station HS2-ARP-09-DR-BL-90521 Fazeley Street Terminus - 905 Plan & A-A / B-B Sections 1:1000 @ A1

Birmingham Station HS2-ARP-09-DR-BL-90550 Fazeley Street Terminus - 905 Construction Site 1:2000 @ A1

Birmingham Station HS2-ARP-09-DR-BL-91303 Warwick Wharf Terminus - 913 1:1000 @ A1

Birmingham Station HS2-ARP-09-DR-BL-91321 Warwick Wharf Terminus - 913 Plan & A-A/B-B Sections 1:1000 @ A1

Birmingham Station HS2-ARP-09-DR-BL-91350 Warwick Wharf Terminus - 913 Construction Site 1:2000 @ A1

Birmingham Station HS2-ARP-09-DR-BL-91360 Warwick Wharf Terminus - 913 Layout, Section and 3D Images 1:1000 @ A1

Interchange Station HS2-ARP-09-DR-BL-91421 Interchange Station - 914 Plan & A-A / B-B Sections 1:1000 @ A1

Birm

ingh

am S

tatio

n

Interchange Station HS2-ARP-09-DR-BL-91451 Interchange Station - 914 Construction Site 1:2500 @ A1

Drawing Number Description Scale Delta Junction & WCML HS2-ARP-05-DR-RW-15100 Key Plan - West Midlands Area, Delta

Junction and West Cost Tie-in 1:50000@A1

Delta Junction & WCML HS2-ARP-05-DR-RW-15101 Delta Junction West Midlands Area Plan

Profile Sheet 1 of 5 1:2500@A0 Delta Junction & WCML HS2-ARP-05-DR-RW-15102 Delta Junction West Midlands Area Plan




Profile Sheet 5 of 5 1:2500@A0

Del

ta J

unct

ion

and

WC

ML

Delta Junction & WCML HS2-ARP-05-DR-RW-15106 West Coast Mainline Tie-in, West Midlands

Area (Lichfield) Plan Profile Sheet 1 of 1 1:2500@A0

Drawing Number Description Scale Route 2.5 HS2-ARP-07-DR-RW-02100 Route 2.5 Key Plan 1:250000@A1

Route 2.5 HS2-ARP-07-DR-RW-02101 Route 2.5 Plan and Profile sheet 1 of 12 1:10000@A1











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Keyplan HS2-ARP-06-DR-RW-01000 Notes for London Approach Drawings and Heathrow Options N/A

T5 Loop HS2-ARP-06-DR-RW-01511 T5 - Option 1 - Loop - Sheet 1 of 6 1:10,000@A1






T5 Spur HS2-ARP-06-DR-RW-02521 T5 - Option 2 - Spur - Sheet 1 of 4 1:10,000@A1




T6 Loop 1 HS2-ARP-06-DR-RW-01611 T6 - Option 1 - Loop - Sheet 1 of 5 1:10,000@A1













Hub Loop 1 HS2-ARP-06-DR-RW-01711 Heathrow Hub - Option 1 - Loop - Sheet 1 of 4 1:10,000@A1




Hub Spur HS2-ARP-06-DR-RW-02721 Heathrow Hub - Option 2 - Spur - Sheet 1 of 3 1:10,000@A1









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Old Oak Common HS2-ARP-06-DR-BL-60503 Platform and Concourse Plan 1:2500@A1

Old Oak Common HS2-ARP-06-DR-BL-60531 Section AA and BB 1:500@A1

Old Oak Common HS2-ARP-06-DR-BL-60551 Construction site 1:2500@A1

Heathrow Terminal 5 HS2-ARP-06-DR-BL-60721 Section AA 1:1000@A1

Heathrow Terminal 5 HS2-ARP-06-DR-BL-60731 Platform and Concourse Level - Terminus 1:2000@A1

Heathrow Terminal 5 HS2-ARP-06-DR-BL-60751 Construction Site - Terminus 1:2000@A1

Heathrow Terminal 5 HS2-ARP-06-DR-BL-61101 Platform and Concourse Level - Through 1:2000@A1

Heathrow Terminal 5 HS2-ARP-06-DR-BL-61151 Construction Site - Through 1:2000@A1

Heathrow Terminal 6 HS2-ARP-06-DR-BL-60631 Platform and Concourse Layout - Through 1:2500@A1

Heathrow Terminal 6 HS2-ARP-06-DR-BL-60632 Platform and Concourse Layout - Terminus 1:2500@A1

Heathrow Terminal 6 HS2-ARP-06-DR-BL-60633 Section AA and BB 1:500@A1

Heathrow Terminal 6 HS2-ARP-06-DR-BL-60651 Construction Site - Through 1:2500@A1

Heathrow Terminal 6 HS2-ARP-06-DR-BL-60652 Construction Site - Terminus 1:2500@A1

Heathrow Hub HS2-ARP-06-DR-BL-60805 Platform and Concourse Level - Through 1:2500@A1

Heathrow Hub HS2-ARP-06-DR-BL-60833 Section AA and BB 1:500@A1

Heathrow Hub HS2-ARP-06-DR-BL-60851 Construction site - Through 1:2500@A1

Heathrow Hub HS2-ARP-06-DR-BL-60901 Platform and Concourse Level - Terminus 1:2500@A1

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Heathrow Hub HS2-ARP-06-DR-BL-60951 Construction Site - Terminus 1:2500@A1

Drawing Number Description Scale Route 4 HS2-ARP-07-DR-RW-04100 Route 4 Key Plan 1:250000@A1
























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Appendix H New Street Key Issues


Page H1 Ove Arup & Partners Ltd15 December 2009

1H New Street Station

H1.1 Introduction

This report summaries the design development of the Birmingham New Street Option for HS2. It addresses the following Key Issues.

Southern Approach & Tunnels

Structural Gauge

Platform lengthening

Displaced services – Operational considerations

International Facilities

Note that the widening and lowering of the west side tunnel between Moor Street and New Street summarised below is the subject of a separate more detailed report. Similarly, Operational Issues have also been developed and reported on under separate cover.

H1.2 Southern Approach and Tunnel

The proposed HS2 duplex rolling stock requires an increase in the structural gauge to GC – affecting both height and width. The existing station has not been designed for this gauge. Both the tunnels to the east and the air rights structure above give insufficient vertical clearance to the tracks.

The existing tunnel profile varies between approximately 5.2 to 5.6m in height at its crest, 6900mm to 7400mm in width and comprises brick arch rings, with short piers. The tunnel is situated within a densely built up environment of Birmingham City centre.

The tunnel is partially located below Moor street station and a railway bridge to the east. There is a steep gradient in the track from the tunnel under Moor Street to the arched viaduct over Fazeley Street. The existing gradient is approximately 2% (Gradient 1:50). A railway viaduct is situated to the east of the Moor Street, comprising multi span brick arches and flat deck underbridges over roads supported on brickwork piers/abutments on spread footings.

There are shallow strip foundations, piled foundations supporting low and medium level buildings including the foundations to the high level Rotunda structure situated in close proximity to the tunnel. The new Bull Ring Retail Complex is situated to the south of the tunnel. Contiguous piled wall and bored piled on concrete pads/RC columns are constructed adjacent to the new Bull Ring Centre, located either side and between the existing East & West tunnels, supporting two levels of highway, comprising precast and / RC downstand beam decks



From available survey data, the approximate levels of key structural elements to the east are:-

Approximate Level Clearance

(incl. structure)

i) Bullring circulation deck 130m OD II) St Martins Queensway 123m OD 7m iii) New Street eastbound track 117m OD 6m

The vertical clearances for both road and rail appear to be based on a minimum provision. (This is supported by the humped nature of the pedestrian deck, and, the structural form of buildings above the road which are ‘hung’ from long span trusses).

In order that High Speed trains are able to go through New Street Station, the existing brick arched tunnel needs to be lowered and widened by approximately 1.5m to accommodate the required UIC Gauge for the High Speed (double deck) trains.

The new tunnel profile will be a minimum of 8900mm in width. This will involve the demolition of the existing tunnel and masonry piers as well the removal of overburden above the existing tunnels and to underside of roadway deck construction.

It is envisaged that the construction method would be limited to short length tunnelling methods constrained by the existing structures above.

The approaches to the Fazeley Road viaduct lie on a steep gradient (approximately 1:50) from Moor Street rising over the Fazeley road approximately 400 metres to the east of Moor Street Station. The lowering of the tunnel below the tracks by 1.5 metres at Moor Street would result in a steeper track gradient. Measures to lower the west end of the Fazeley viaduct are required as a result, or reconstruction of the viaduct up to Fazeley Street may be needed.

H1.3 Structural Gauge

Similarly, the tracks for HS2 and platforms (1, 2/13, 4/5) will also have to be lowered to provide headroom beneath the concourses and shopping centre above.

The existing New Street station concourse substructure and foundations situated below the new lines also need to be modified and/or strengthened or partially replaced to accommodate the track lowering.

There are two subways under the existing platforms servicing the station. These accesses will need to be maintained and the subways will require lowering or relocating with associated underpinning of adjacent foundations.

New Street Station is situated approximately 50 metres from the ends of the tunnel. In order to accommodate the 1.5m lowering of the track and replaced Western Rail tunnel, the two east tracks leading from the tunnel of the New Street Station will require lowering by 1.5m. This would require the closure of parts of the station to accommodate the temporary works for the construction of bored piled retaining walls.



It would not appear appropriate to lower the other three tunnels or remaining station which would be an extensive exercise.

This results in a split throat to the east with two dedicated lines servicing only HS2, and two lines to the domestic station. Since domestic services cannot use HS2 platforms this may not be an issue.

It should also be noted that the vertical circulation between the lowered platform and the new gateway concourse will require replacement (escalators, lifts/ stairs).

H1.4 Platform Lengthening

The existing station platforms are all too short to support HS2 trains (415m). Four options have been considered.

Option 1 - All platforms 400m long (See Drawing 90381)

The east ends of all platforms have been projected as far eastward as possible to minimise the impact of the longer platforms, overruns and buffer stops at the west end. However, this option affectively fully blocks the western approach track fan – clearly unacceptable.

Option 2 - Platforms 1 & 2.3 400m long Platform 4/5 at lest 265m long (See Drawing 90382)

Again the east end of platforms 1, & 2/3 have been projected eastwards. The resulting impact of their west end is to leave only two of the four western approach tracks available. (This matches the two eastern approach tracks and therefore a balanced station but with reduced capacity, may be achieved).

Option 3 – Platform 1 shortened to provide for 320m train, Platform 2/3 at 400m, Platform 4/5 at least 265, (See Drawing 90383)

In this case by shortening platform 1 it is possible to realign its west end to take space immediately east of the Navigation Street abutments. This enables the tracks serving the west end of platform 2/3 to be slewed about 2.5m northwards, which in turn creates pace behind the new track buffer stops to pass four western approach tracks. This is subject to more detailed study of the east-west end throat geometries and minimum over run provisions.

The reduced length of Platform 1 will also be more acceptable as the west end cul-de-sac will be significantly less long.

Option 4 – Platform 1, 2, 3 or 400m by, platform 4/5 at least 265 (see 90384)

In this case the platforms are extended beyond the station …. Note at the North West comer taking additional site currently occupied by car parking, the north bridge abutment (necessitating, reconstructing the bridge) and the site designated for a new hotel. Not only will this achieve the 400m platform length, platform 1, 2, 3 but also by straightening their



alignment the impact on the western station approach is reduced provisionally to allow 4 western approach tracks.

For Option 4 new platforms are tapered providing a maximum width of:

Platform 1 4.0m

2/3 11.5m

45 11.3m

existing platforms are unaltered.

In all options access to platforms 1, 2 and 3 is poor, Platforms 2 and 3, as the new ‘gateway concourse’, are not central to the platform, and additionally for platform 1 the platforms a narrow cul-de-sac about 200m long.

The remodelling of the throat & platforms will require extensive re signalling.

H1.5 Displaced Services

Arup carried out a review for the ORR of the passenger modelling work carried by Network Rail for the Birmingham New Street Gateway development.

Documents made available included GRIP4 reports, and the Scott Wilson PAXPORT model (received March 2008). Typical peak hour movements of 40tph were reported however the report did not differentiate between through and terminating services.

Based on passenger movements Platforms 1-5 account for approximately 40% of the station through put, which would either be displaced to other platforms, or be lost.

Similarly the dedication of two of the four Eastern approach tracks to HS2 removes up to 50% of the station capacity. The Eastern approach is reputed to be amongst the most densely trafficked sections in the UK so this loss may be fully realised.

To provide for displaced services a new station would be required with up to 8 no platform edges up to 320m long for Pendelno Trains

As a possible compensation, a route has been reserved by BCC for a Cross City service in tunnel with a domestic two platform through station about 25m beneath New Street. By inspection this may compensate for the losses incurred providing for HS2. However, passenger demand forecasts indicate significant growth at New Street which was the driver both for the Gateway enhancements (mainly platform access) and the Cross City Studies.

The assessment of New Street for HS2 should therefore include for growth in existing service demand plus HS2.



A more detailed assessment of operational issues has been issued under separate cover. It is particularly noted that:

A) Coventry Corridor Displaced Services

Services on this corridor use the Western Lines approach to New Street and generally the low numbered platforms and will have to be diverted. There are 9 services each way in ‘standard’ hours and 10 trains in some hours on the Coventry Corridor. While this includes 3 London-Birmingham fast services, which would be diverted to HS2, it can be expected that these will be replaced by other services due to the pressure on capacity on this corridor. Therefore, 10 trains each way would need to be allowed for.

B) Wolverhampton, Stour Valley Services

There are 10 or 11 trains per hour on this corridor. It is assumed that all except the ‘stopping’ services would need to be diverted due to the limited capacity on New Street and the need to keep the same terminal for groups of services. For this reason, it is also assumed that the 2tph Rugeley-Walsall-Birmingham trains via Soho would also need to be diverted. Diversion of services would also allow Centro to achieve its aspiration to increase the Stour Valley stopping service from the current 2tph to 4 or 6 tph. This would lead to the need to divert 9 + 2 = 11tph each way.

Due to the long north tunnel, the extent of the city centre and the remoteness from the other terminals, there is no opportunity for a new terminal station to the north of New Street. The trains will have to be diverted to a new station to the south of the city centre – shared with the displaced Coventry corridor services.

The likely preferred option would use the Grand Junction route throughout, much of which is currently 70/75mph. This route is heavily used by freight and passenger services, in summary:

Walsall – Birmingham stopping services (2tph)

Cross-City North services (6tph)

Infrequent other services, notably Wrexham-Shropshire

These services, and the 11tph needing to be diverted, could not be accommodated on a 2-track line and therefore 4-tracking will be required. Due to the operational differences between freight and stopping and fast services, the 4-tracking would need to extend from Bescot to the new Birmingham station, although part of the route could make use of the current disused 2-tracks between Ashton South Junction and Proof House Junction. The flat junctions at Aston and Perry Barr would be retained in remodelled form. The works would require land and property take and reconstruction of the intermediate stations other than Duddeston.



H1.6 International Facilities

As previously noted Platform 1 could provide dedicated facilities for International Services directly to Europe. It is proposed to open up the central area north of the platform to provide check in and security at platform level with access from the concourse above. (Special provisions are not required for arriving passengers). (See Drawing 90383)

The logistics of servicing, and back of house facilities for this International Service have not yet been investigated.

However vehicle access to this location within the gateway proposal appears limited.


Appendix I New Street Structural


Page I1 Ove Arup & Partners Ltd15 December 2009

1I Introduction This report is a summary of an initial feasibility study undertaken for the New Street South Tunnel – Western Line Tunnel - enlarging of the west side tunnel to New Street Station on behalf of HS2.

The work focussed on the constraints present by existing infrastructure around the tunnel bores and was based on the available ‘as built’ information provided by HS2.

The New Street South Tunnels comprise the New Street Old tunnel (Western Rail Tunnel) built circa 1850 and the Eastern tunnel (also known as the Midland lines tunnel) was subsequently constructed circa 1890.

2I Existing Construction and Clearances The existing tunnel profile varies between 6900mm to 7400mm in width and comprises brick arch rings, with short piers. The tunnel is situated within a densely built up environment of Birmingham City centre.

The tunnel is partially located below Moor street station and a railway bridge to the east. There is a steep gradient in the track from the tunnel under Moor Street to the arched viaduct over Fazeley Street. The existing gradient is approximately 2% (Gradient 1:50). A railway viaduct is situated to the east of the Moor Street, comprising multi span brick arches and flat deck underbridges over roads supported on brickwork piers/abutments on spread footings..

There are shallow strip foundations, piled foundations supporting low and medium level buildings including the foundations to the high level Rotunda structure situated in close proximity to the tunnel. The new Bull Ring Retail Complex is situated to the south of the tunnel. Contiguous piled wall and bored piled on concrete pads/RC columns are constructed adjacent to the new Bull Ring Centre, located either side and between the existing East & West tunnels, supporting two levels of highway, comprising precast and / RC downstand beam decks.

New Street station is situated to the West of the tunnel, comprising several tracks and platforms situated within an area enclosed by original brick retaining walls with the station complex above the lines/platforms.

3I Gauge Requirements In order that High Speed trains are able to go through New Street Station, the existing brick arched tunnel needs to be lowered and widened by approximately 1.5m to accommodate the required UIC GC Gauge for the High Speed trains. It is assumed that the new tunnel will be of constant width to encompass the widest section of existing tunnel and any provisions for refuges and emergency access within.

The existing tunnel layout accommodates the current Class 373 envelope however there is insufficient space for the proposed Structure Gauge clearance within the existing profile.

4I New Proposals The new tunnel profile will be a minimum of 8900mm in width to accommodate the new UIC-GC Gauge. This will involve the demolition of the existing tunnel and masonry piers as well the removal of overburden above the existing tunnels and to underside of roadway deck construction.

The tunnel east of New Street is predominantly overspanned by new highway structures built in 2003 as part of the Bull Ring Complex. It is envisaged that the construction method would be limited to short length tunnelling methods constrained by the existing structures above.



5I Key Constraints I5.1 East approach Viaduct

The approaches to the Fazeley Road viaduct lie on a steep gradient (approximately 1:50) from Moor Street rising over the Fazeley road approximately 400 metres to the east of Moor Street Station. The lowering of the tunnel below the tracks by 1.5 metres at Moor Street would result in a steeper track gradient. Measures to lower the west end of the Fazeley viaduct are required as a result, or reconstruction of the viaduct upto Fazeley Street may be needed.

The multi-span brick arched viaduct includes several road underbridges to the east. The construction form of the bridges may not accommodate track lowering above. In this instance a new viaduct maintaining highway headroom clearances to roads beneath would be required.

Furthermore, if headroom clearances cannot be maintained to roads by the lowering of the railway alignment, the highway alignment beneath will need to be lowered accordingly. If the access to the adjacent properties are to be maintained, the lowering of the adjacent highways may prove further complex engineering obstacles or result in the relocating of property accesses. The viability of this solution may be compromised if accesses to adjacent properties cannot be maintained as a result of the ground lowering.

The abutment/foundations to overbridges will require strengthening/underpinning to accommodate the track lowering east of Moor Street.

I5.2 West side – New Street Station

New Street Station is situated approximately 50 metres from the ends of the tunnel. In order to accommodate the 1.5m lowering of the track and replaced Western Rail tunnel, the two east tracks leading from the tunnel of the New Street Station will require lowering by 1.5m. This would require the closure of parts of the station to accommodate the temporary works for the construction of bored piled retaining walls.

The existing platform to the Western Rail tunnel is likely to be shorter than the required length for the proposed new high speed trains. There may be insufficient space to accommodate this.

The existing New Street station concourse substructure and foundations situated above the existing lines might need to be modified and/or strengthened or partially replaced to accommodate the track lowering.

There are two subways under the existing platforms servicing the station. These accesses will need to be maintained and the subways will require lowering or relocating with associated underpinning of adjacent foundations.

I5.3 Approach Viaduct – East – Retaining walls and track support

Retaining walls along the eastern approach between the Fazeley Viaduct and Moor Street Station will need to be strengthened, underpinned or replaced to accommodate the track lowering of 1.5m along the approaches to the east side of Moor Street Station.

I5.4 Bull Ring Complex

It appears that the space available adjacent to the Bull Ring Complex is able to accommodate the geometric requirements of the UIC Gauge without obstructions from the recent development. However there are a number of constructional unknowns which will require further detailed investigation determine whether the options are technically feasible.

The multi level bridge structure supporting St Martins Circus Ringway is situated above the tunnel roof situated from New Street to Moor Street. The method of construction for the replacement tunnel will be constrained by this physical obstruction.



The contiguous piled wall and bored piles with concrete pads/RC elevated structure supporting the highway on columns and Bull Ring complex are founded approximately 8 metres below the proposed lowered tunnel track level and would need to be assessed for the effects of the removal of the existing tunnel.

There may be deep/piled foundations of retail development extensions that would be situated very close to the line of the widened tunnel. The effect of the tunnelling lowering on the existing structures will need to be investigated in detail.

I5.5 Rotunda multi-storey Complex

The Rotunda Complex situated very close (within a few metres) to the existing wall of the Western tunnel and little information has been obtained on the foundations at this point. The foundations are anticipated to consist of deep bored concrete piles. There is the risk for the adjacent ground to be partially subjected to the surcharge from the building self weight.

Further stabilising and underpinning of the foundations to the Rotunda building may be required due to the removal of the existing tunnel. The new tunnel would potentially be designed for an element of surcharge from the building foundations or underpinning required to the Rotunda foundations.

Further detailed studies will be required to determine whether the replacement tunnel is technically feasible.

I5.6 Moor Street Station

The north-east section of Moor Street station is situated over the two New Street South Tunnels. The lowering of the eastern tunnel may involve the partial closure of part of the Moor Street Station to accommodate temporary works for the construction of the new tunnel by a cut and cover method.

There could also be further underpinning required of the retaining walls bordering the highway/ Moor Street station as well as part of the platform structures. This would also include underpinning of the bridge which carried part of the Moor Street station.

I5.7 Retail Structures foundation

Generally the existing retail buildings to the north of the existing Western Tunnel are a mixture of Victorian/historic and modern framed structures supported on a mixture of original spread foundations and/or concrete piled foundations supporting modern extensions and refurbishments. The full extent and position of the foundations is not known.

These structures are situated adjacent to and partially directly above the proposed new tunnel and would need to be assessed for the effects of the removal of the existing tunnel. There will be a significant risk that any potential ground movements derived from the temporary works will affect the existing old structures which may be susceptible to ground movements.

It is anticipated that ground stabilising works and/or underpinning of these structures will be required in advance of the works.

I5.8 Statutory Services

The tunnels are situated below existing established highways and in an area of densely populated infrastructure within the centre of Birmingham.

The zone around the tunnels is expected to be densely populated with statutory undertaker’s plant and services and any proposals to excavate around the existing infrastructure are likely to involve significant and costly statutory diversions.

6I Risks – General



The estimate is based on the limited desk study information available at this stage of the project. There is a risk that the following works will be required and additional costs will occur:

• The design of the contiguous piled wall supporting the Bull Ring complex relies on soil subgrade reaction from the existing tunnel and overburden. Strengthening or/and underpinning of a series of contiguous piled walls/RC retaining walls/ existing building foundations will be required.

• The design of the RC highway approach decks relies on the subgrade reaction from the existing (over the roof of the tunnel). Strengthening of the bridge decks spanning over the tunnels could be required.

• The soffit profile of the varying depth RC downstand beams will obstruct the required UIC CG-Grade railway envelope and clearance.

• Closure of part of New Street and Moor Street Stations may be needed.

• A new portal framed structure (or cantilever diaphragm wall) will be required to be constructed adjacent to the existing to resist the surcharge loads from adjacent buildings.

• Lowering of the railway by 1.5m to the west side will adversely affect the stability of the Eastern Rail tunnel (in the temporary and permanent cases) and significant propping or stabilising works will need to be addressed to the base and roof of the existing tunnel.

• The foundations to major structures (i.e. the Rotunda) will be potentially undermined by the reduced lateral subgrade reaction provided by the temporary works. Further ground stabilising works or/and underpinning will need to be carried out in this respect.

• The station at Moor Street would need to be closed to enable excavation of the eastern tunnel to undertake a cut and cover replacement. Further strengthening/underpinning of the approach walls to the tunnel will be required.

• A new multi-span viaduct would be required to the east of Moor Street Station over four roads from Fazeley Street to Banbury Street. (with localised lowering of roads)

• Significant parts of New Street Station will need to be closed to lower the track adjacent to the New Street South Tunnels by 1.5 metres. Extensive strengthening/underpinning of the existing old Victorian vaulted brickwork retaining walls will be required.

• Statutory diversions will be required which are likely to be complex and expensive.

• Complicated lowering of adjacent highways and relocation of property accesses may be necessary west of Moor Street Station.

• Extensive underpinning of existing building structures and highway/railway bridges where ground lowering is implemented.

•

7I Conclusion

The lowering of the tracks by approximately 1.5 metres is required to accommodate the High speed train Gauge within several complicated physical and engineering constraints imposed by the established built up environment and infrastructure surrounding the tunnel alignment.

The complexity of the local infrastructure and challenging engineering constraints will need to be addressed in much greater detail within further Feasibility Studies and Options



Reports in order that an accurate cost is achieved. Further detailed investigation and options studies are required to examine technical solutions in detail.

The choice of structural form for the new tunnel could vary depending on the method of construction relevant for the particular constraint, which would affect the overall construction cost.

8I Appendix 1 - Map of Birmingham New Street and surrounding area



9I Appendix 2 - New Street South Tunnel gauging information



10I Appendix 3 - Plan View, Moor Street Station to Faseley Road viaduct

11I Appendix 4 - Plan View, New Street Station to Moor

Street Station



12I Appendix 5 - Typical Cross section through existing tunnel


Appendix J HS2 Birmingham New Street Station Option - Operational Considerations


Page J1 Ove Arup & Partners Ltd15 December 2009

1J Introduction This technical note considers the railway operational issues arising from proposals to convert the Platforms 1-5 area of Birmingham New Street, and the associated Western Lines approach tracks from Proof House Junction, into a terminal station for HS2. As a consequence the trains currently using the Western Lines approach and Platforms 1 -5 will need to be diverted to other routes and other stations. Some trains using platforms 6 & 7 would also need diversion due to the need to reconfigure the track layout to accommodate the HS2 station.

The structure of the remaining sections of the report is as follows:

• In Section 2, the most likely HS2 Birmingham station layout and configuration, and their impacts on existing train services are discussed.

• Chapter 3 outlines the impacts on passenger train services that currently use Birmingham New Street station and which will be displaced in order to make way for the HS2 services. It also describes how the impacted services would need to be diverted to a new Birmingham Terminal station and gives possible diversionary route options. The requirements and consequences of the diverting services are also discussed;

• Chapter 4 gives a brief on the layout of the new Birmingham Terminal;

• Supporting drawings, train graphs and calculation sheets are attached in the Appendices.

2J HS2 Birmingham Station J2.1 Configuration of HS2 Station

The HS2 new line is likely to lead to the Birmingham City centre station being used by the following domestic services.

Table 1: Trains that could use the HS2 Birmingham Station

Service Minimum

Frequency (tph) Likely peak

Frequency (tph) Long term

Frequency (tph)

London – Birmingham Fast 2 3-4 4-6

Birmingham - Manchester 1 1-2 2

Birmingham - Glasgow 1 1 1

Birmingham - Edinburgh 1 1 1

Birmingham - Liverpool 0-1 0-1 0-1

Totals 4-6 6-9 8-11

Platform Requirement (2 uses per hour)*

2-3 3-5 4-6

* (HS2 Project Specification Section 2.3.6 – minimum requirement)

NOTES:

(i) The above excludes any trains that might use the HS2 Birmingham Branch and Derby line connection to give improved services and journey times from Birmingham to Nottingham, Sheffield etc.



(ii) The above is a minimum and assumes that all trains will be return workings, with no ‘empty-stock’ movements and that train layovers between arrival and departure can be kept to an average of no more than 20 minutes. This is quite a small allowance for long-distance trains, leaving limited time for recovery from late arrivals, or for matching in and out diagrams. It is probably unlikely to be resilient, especially for the Birmingham-North services, which will have to operate for some time at least, if not always, over the ‘Classic’ network.

(iii) International services, if operated, are likely to require much longer occupations of a platform, probably at least 40 minutes, to allow for cleaning, servicing, loading and unloading, and some resilience to late arrivals, particularly because of the security requirements. This would be in addition to the trains in Table 1 and hence, would require an additional platform to those included in the table above, even if services were infrequent.

Therefore, based on the above, the minimum platform layout for the HS2 Birmingham station is 4 to 7 platforms.

J2.2 Platform Layout

It is assumed that the HS2 station would consist of 5 terminal platforms, at least 2 of which need to be full 415 m in length (see notes);

For the Birmingham – North trains which could use the HS2 station, these would be limited in length to a maximum of 260m or 320 metres while operating over the ‘Classic’ network, with the following provisos:

• Possible operation as coupled 400 metre sets to say Crewe to minimise use of train paths, or allow a wider variety of through services;

• Possible requirement for 400 metre sets on some or all of these services when the High Speed route is extended.

The possible layout of the HS2 station is shown on drawing HS2-ARP-09-DR-BL-90384 (Appendix A1). It should be noted that the layout as shown on the drawing would not allow the simultaneous use of platforms 1 and 2 by full length trains, and a revised configuration, requiring more engineering work, would be required to deliver the capacity.

J2.3 Impact on the Existing New Street Station

The proposed HS2 terminal would lead to the following changes at Birmingham New Sreet:

• Loss of Platforms 1-5 and Bay 4C to existing services;

• Conversion of Platform 6 into a north facing terminal platform;

• Shortening of Platforms 7 and 8 to reflect routeing of trains at south end to the Derby lines only;

• Loss of the Up and Down Stour (Western) lines approaches through New Street South Tunnels;

• Some loss of parallel movement opportunities in the station throats.

This reduction in facilities will lead to displacement of services from the station and approach lines. New station facilities and track capacity will be required to replace the lost facilities and capacity.



3J Displaced Services J3.1 Coventry Corridor Displaced Services

Services on this corridor use the Western (Stour) Lines approach to New Street, and generally the low numbered platforms. Both the Western Lines approach to New Street and platforms 1-5 will be handed to HS2 and the trains that currently use them will have to be diverted. There are 9 services each way in ‘standard’ hours and 10 trains in some hours on the Coventry Corridor. While this includes 3 London-Birmingham fast services, which would be diverted to HS2, it can be expected that these will be replaced by other services, due to the pressure on capacity on this corridor.

A train graph of the current timetable showing services in the period 1500-1900 hours for the Western (Stour) lines in the down direction through Birmingham New St. is attached in Appendix A2.

J3.2 Wolverhampton and Stour Valley Services

There are generally 10 or 11 trains per hour on this corridor. It is assumed that all except the ‘stopping’ services would need to be diverted, due to the limited remaining capacity at New Street, and the need to keep the same terminal for groups of services. For this reason, it is also assumed that the 2tph Rugeley-Walsall-Birmingham trains via Soho would also need to be diverted.

Diversion of services would allow Centro to achieve its aspiration to increase the Stour Valley stopping services from the current 2 tph to 4 or 6 tph, which would give same benefit from the diversions which would otherwise have negative impacts.

Table 2: Total number of trains displaced from Birmingham New St. in each direction 15.00 to 19.00

Direction Down Up

No. of Displaced Trains 71 73

Total No. of Trains 154 157

Extent of Displacement 46.1% 46.5%Displaced TPH 14.2 14.6

Due to the long north tunnel, the extent of the city centre and the remoteness from the other terminals, there is no opportunity for a new terminal station to the north of New Street. The trains will have to be diverted to a new station to the south of the city centre, shared with the displaced Coventry corridor services. There are two possible routes for diversion:

• Via the Soho loop (Smethwick-Perry Barr);

• Via the Grand Junction line (Wolverhampton – Portobello – Bescot – Aston).

The former involves the least extent of diversion but has significant disadvantages:

• Long roundabout route, adding significantly to journey time;

• Soho loop is a poorly aligned, low speed route, which would be very difficult to upgrade;

• It would prevent the option of upgrading the local passenger service.

Hence the preferred option would be to use the better aligned Grand Junction route throughout, much of which is currently 70/75 mph. This route is heavily used by freight and passenger services, in summary:

• Walsall – Birmingham stopping services (2 tph)



• Cross-City North services (6 tph)

• Infrequent other services, notably Wrexham-Shropshire

• Various freight movements.

These services and the trains needing to be diverted could not be accommodated on a 2-track line, and therefore 4 tracking will be required. Due to the operational differences between freight, and stopping and fast services, the 4-tracking would need to extend from Bescot to the new Birmingham station, although part of the route could make use of the currently disused 2 tracks between Aston South Junction and Proof House Junction. The flat junctions at Aston and Perry Barr would be retained in remodelled form. The works would require land and property take, and reconstruction of the intermediate stations, other than Duddeston.

Table 3: Expected frequency on the New Birmingham–Aston–Bescot–Wolverhampton line

Current TPHPD Section Displaced

TPHPD Up Down

Future TPHPD (rounded up)

No. of Tracks

Required

Birmingham – Aston 8.2 8 10 19 4

Aston – Perry Barr 8.2 2.5 4.5 13 4

Perry Barr - Hampstead 8.2 4.5 4.5 13 4

Hampstead - Bescot 8.2 4.5 4.5 13 4 Bescot – Wolverhampton 6.2 0.5 0.5 7 2

In addition, the route will require some upgrading throughout to allow higher speeds and minimise the journey time disadvantage of the new route.

J3.3 Journey Times

The rerouting of trains would have adverse journey time impacts for trains diverted from the Wolverhampton line as shown in Table 4. This would be a particularly negative impact as many services on this corridor are already slow.

Table 4: Journey times for trains diverted to the new Birmingham Terminal via Aston

From To Current Average

Journey Times using Birmingham New St.

Expected Journey Times using the new Birmingham

Terminal via Aston Birmingham Wolverhampton 18min 25min* Birmingham Aberystwyth 3hr 2min 3hr 9min Birmingham Liverpool 1hr 38min 1hr 45min Birmingham Glasgow 4hr 10min 4hr 17min Birmingham Edinburgh 4hr 4min 4hr 11min Birmingham Shrewsbury 1hr 2min 1hr 9min Birmingham Rugeley TV 57min 1hr 4min (S), 57min (F)

Bournemouth Manchester 4hr 55min 5hr 9min^ * Only for fast trains between Birmingham and Wolverhampton ^ Extra 5 minutes platform re-occupation time at new B’ham terminal



4J New Birmingham Terminal Station It is assumed that a new terminal station would be built in the Moor Street/Warwick Wharf area, with pedestrian links to New Street and Moor Street stations. This would require grade separated new routes crossing the existing lines and HS2 from the Coventry and Aston/Grand Junction lines.

Preliminary analysis of current (Summer 2009) operations indicates that 14 pairs of services will need to be diverted away from Birmingham New Street to the new terminal station. These would require a minimum of 7 new terminal platforms. The calculation of the number of platforms required is shown in Appendix A3.

For passengers wishing to interchange with services remaining at New Street there will be significant adverse connection time and perception impacts. This would also apply to those wishing to access the busy New St. / Corporation St. shopping and business area.

5J Conclusions Use of Birmingham New Street as the Birmingham station for HS2 would require the following;

• Closure of the existing Platforms 1- 5 and the Western Lines route into New Street from Proof House Junction;

• Conversion of this area into the HS2 station approach and terminal station. Due to the larger HS2 gauge this will involve lowering the tracks by about 1.5 metres, effectively preventing connections between the HS2 station and the existing railway in the New Street area;

• Reconfiguring the platforms 6 & 7 tracks to accommodate the HS2 station, making Platform 6 a terminal platform from the north;

• Diversion of the trains displaced from New Street by the HS2 station to a new station in the New Street/Warwick Wharf area;

• Provision of a new terminal station with at least 7 platforms for displaced services;

• Construction of new rail links from the Coventry and Grand Junction lines to the new station;

• Four-tracking of the Proof House – Aston – Bescot route to accommodate the trains displaced from the Wolverhampton line.

Diversion of services from New Street to a new terminal station will have passenger impacts;

• Longer journey times for passengers on the Wolverhampton corridor (See Table 4);

• Significantly greater interchange penalties for passengers wishing to interchange onto trains still using New Street (including HS2 services);

• Interchange times to Moor Street trains would probably be similar to current;

• Longer journey times for passengers whose destinations are in the New St./Corporation Street and Convention Centre areas of Birmingham, and to some bus routes.



6J Drawing – Birmingham New St. Platform Options

7J Down Direction Train Graph for Birmingham New St. (15:00–19:00)

Western (Stour Valley) Lines: Dn Off-peak + PM Peak

Coventry / B'ham International - B'ham Locals

RUGBY

SANDWELL & DUDLEY

BIRMINGHAM NEW ST.

STAFFORD

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Stafford Trent Valley Jn.

WOLVERHAMPTON

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SMETHWICK GALTON BR.

Cross Country trains via B'ham Walsall - B'ham - W'hampton Local

Rugby Trent Valley Jn.

London MYB - Wrexham GB'ham In'l - Holyhead / Aberystwyth B'ham - ShrewsburyBirmingham-Stafford-North

London Euston - Northampton - B'ham (LM)

London Euston - Rugby - B'ham - Wolverhampton (VT)

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Note: the 2tph Birmingham-Rugeley-Walsall services are not reflected in this graph because they are directed via Aston. They use the Perry Barr–Soho loop only in the Up direction (from Rugeley) due to operational issues.



8J Calculation of Number of Platforms at the New Birmingham Terminal


Appendix K Maintenance Depot - Washwood Heath Site Appraisal


Page K1 Ove Arup & Partners Ltd15 December 2009

1K Introduction The purpose of this report is to assess the suitability of Washwood Heath for the location of a maintenance depot to support the HS2 fleet. A portion of land at Washwood Heath has been identified as a suitable site for the depot and Arup have been charged with placing an indicative depot layout on the land. This exercise will confirm the suitability of Washwood Heath as a potential depot location as well as informing the land requirements should other depot sites be considered.

2K Inputs The following inputs have been used in the production of the depot layouts:

K2.1 OS Mapping

The layouts produced are based on OS mapping which is considered adequate for the level of design required.

K2.2 Rolling Stock Maintenance Strategy

This HS2 paper (located in Appendix C) sets out the main criteria for the depot, including the number of roads in the maintenance building and the number of stabling roads required.

K2.3 Depot Layout Meeting with HS2 Team

Arup met with the HS2 team to discuss the depot on 11th November 2009. This meeting informed the development of the indicative layouts.

3K Assumptions The following assumptions have been made in addition to those stated in the Rolling Stock Maintenance Strategy paper:

• The whole site as defined by the HS2 team is available but land take has been aligned with the main lines to release as much land as possible for industrial / business use.

• Operational sequence based on: Train in – CET – Washer - Maintenance Shed – Sidings –Train out (as discussed in meeting with HS2 team 10/11/09).

• Mainline turn-outs on straight geometry elements where possible.

• The M6 structure is to be avoided.

• Minimum 40mph connections from main lines.

• There should be a minimum of 6m running edge to running edge between mainline and depot road for depot fencing etc.

• Track spacing within depot layout to be based on 5m running edge to running edge with stabling roads typically 450m long to accommodate double length trains.

• Stabling sidings to provide CET and cleaning facilities.

• Additional stabling to be provided to increase the depot capacity to 30 x 200m long sets (to serve a total fleet size of 57 sets).

• There should be a minimum of 400m clear standage each side of Washer Plant (bi-directional).



• There should be a minimum of 200m clear standage each side of wheel lathe (assume 1 x 10 car unit at a time).

• There should be a minimum of 200m clear standage each side of bogie drop (assume 1 x 10 car unit at a time as discussed in meeting with HS2 team).

• 480m minimum standage required on main line / depot signalling handover roads to allow for a double train set plus required signalling overlaps.

• Double headed wheel lathe to be specified.

• Provision is to be made for an under frame cleaning facility.

• Where possible provision is to be made for expansion of the maintenance shed and the stabling facilities in line with an expansion of the HS2 fleet.

4K Depot Layouts The following sections give details of the various depot elements and descriptions of the two alternative depot layouts proposed.

K4.1 Maintenance Shed

The maintenance shed comprises eight roads, two of which are heavy maintenance roads (with bogie drop facilities) and six of which are light maintenance roads. 5m running edge to running edge track intervals have been allowed between depot roads. 6m has been allowed between the running edges of the outer roads and the wall of the depot building.

The depot building is 450m long which gives 20m clearance at the front of the depot building and 30m clearance at the rear for circulation of materials etc.

The depot building footprint is therefore 450m by 61m.

K4.2 Storage and Offices

Storage facilities are required adjacent to the maintenance shed to serve the various inspections, light and heavy maintenance activities. Offices and other facilities will be required for the site staff and for train drivers signing on at the depot.

K4.3 Layout Options

Two options for depot layouts have been developed, as shown in Appendix A. Depot schematics also considered in developing the options are located in Appendix B.

K4.3.1 Option 1 Option 1 is focussed on delivering a workable depot within the engineering constraints of the site with compromises made in respect to operational performance.

The option provides a hand over area between main line signalling and depot signalling located wholly on the straight portion of track north of the site. The maintenance shed, wheel lathe and four stabling roads are located at the Western end of the site. A further twelve stabling sidings to the Eastern end of the site.

The hand over area comprises four tracks each equipped with CET facilities. Trains entering the site will stop, be subject to CET and then travel to the headshunt coming back through the washer to the main site. The trains may then enter the maintenance shed, the wheel lathe or the stabling sidings



adjacent to the maintenance shed. From the maintenance shed the trains may enter one of the twelve stabling sidings to the Eastern end of the site.

With trains crossing the site from side to side and the reception road varying between one and two roads there is potential for conflicting movements within the layout.

Road access is envisaged from the Eastern road junction where a major elevated roundabout is proposed. The location of the maintenance building and offices at the Eastern end of the site gives the road room to descend from high level at a reasonable gradient.

K4.3.2 Option 2 Option 2 is focussed on delivering a depot with an optimised operational performance with more ambitious engineering solutions proposed.

The aim of this option is to reduce conflicting movements in the depot by moving all facilities to the East of the site and providing two reception roads throughout.

The option is based on two signalling handover sections, one at the West of the site for trains to and from Birmingham and one at the East of the site for trains to and from London. The main line connection at the Western end of the site is siting on a 1600m curve and may be difficult to design install and maintain. A bank of CET sidings is provided at the Eastern end of the site which the train will enter first. The trains will travel to one of four headshunts (2 each to the west and the east of the CET sidings) and on to one of the two washers. The trains may then enter the maintenance shed, the wheel lathe or the stabling sidings by using the two western headshunts.

The multiple crossovers, reception tracks and washers allow for more than one train to be processed at a time and allow parallel movements. This does mean that the washer sidings (450m in length) are not long enough for a 400m train so the train would have to be split into two x 200m units.

The maintenance shed is located at the Eastern end of the site as is the main bank of stabling sidings.

The main road access is from the Eastern road junction while a secondary access could be built using one of the existing southern roads.

K4.3.3 Option 3 Option 3 is focussed on delivering a workable depot within the engineering constraints of the site with some compromises made in respect to operational performance.

This option is takes up a similar amount of land to option 2. The option sacrifices parallel movements to allow for an 850m long washer siding.

The option is based on two signalling handover sections located at the same positions as Option 2. A bank of CET sidings is provided at the Eastern end of the site. To get to these sidings the train will have to go past the entrances to the washer sidings and therefore not allow movement into the washer sidings and the CET sidings at the same time link in Option 2. After the CET sidings the train will travel to one of four headshunts (2 each to the west and east of the CET sidings) and on to one of the two washers. The washers are long enough to allow full 400m train sets unlike in Option 2. The trains may then enter the maintenance shed, the wheel lathe or the stabling sidings by using the two western headshunts. This movement will block all other movements trying to use the western part of the depot.

The maintenance shed and the main bank of stabling sidings are located at the Eastern end of the site in the same position as Option 2.

The main road access is from the Eastern road junction while a secondary access could be built using one of the existing southern roads.



5K Depot Costs Using available cost data from similar depot schemes, the capital cost of the proposed depot is estimated at £105m.

This includes the main elements of:

• Depot signalling.

• OHLE

• Points heating

• Permanent Way

• Telecoms

• Civils and Structures

• Fencing and security.

This figure excludes the following:

• Land Costs

• Offsite highway works

• Main line connections

• Prelims

• Design / Consultancy fees

• Testing and Commissioning

• Any possession or isolation management

• Training

• Spares

• Unmeasured items

• Ground Investigations

• Network Rail PM costs

At this stage a budget of £200m seems reasonable, subject to further design development and consideration of site-specific issues.

6K Conclusions The principle conclusion of the exercise is that the Washwood Heath site appears suitable for accommodating the depot facilities required by HS2 project. The plans show indicative depot layouts, which can form the basis of future depot design development.

7K Further Work Further work required to develop the maintenance depot includes the following:

• A review of overall depot facilities, including stabling requirements.

• A review of operational procedures.

• A review of mainline interfaces, signalling overlaps, train controls etc.

• A review of surrounding land issues including access.



8K Appendix 1 – Drawings

HS2-ARP-05-DR-RW-84901





9K Appendix 2 - Rolling Stock Maintenance Strategy

List of Acronyms

CET Controlled Emission Toilet TSI Technical Specifications for Interoperability

K9.1 Introduction

Introduction of HS2 services entails provision of facilities to service and maintain the rolling stock used to run these services. Two different types of passenger high speed stock will be used:

• “Off the shelf” TSI-compliant stock for the HS2 services running on the dedicated HS2 route

(initially London – Birmingham only) • Modified, smaller gauge, high speed rolling stock compatible with the UK classic network for

services running along and off HS2 to other destinations

This strategy outlines how both types of stock will be maintained, stabled and serviced. As far as possible, empty coaching stock movements will be minimised for wear and tear, carbon footprint plus operational capacity and maintenance access impacts.

In developing the strategy, the experience of several rolling stock suppliers / maintainers has been sought and the HS1 Eurostar experience has been highly instructive.

K9.2 Fleet Size

The Day 1 HS2 fleet size is estimated at 52 trainsets:

• 10 GC-gauge trainsets for HS2 captive services (London – Birmingham) • 42 UK1-gauge classic compatible trainsets (covering London – other destinations)



Whilst this scale of fleet size has been considered in developing this strategy, passive provision for future increases in the size of the high speed fleet will be made, where possible. Depot provision will be required up to one year in advance of Day 1 to facilitate testing / commissioning / delivery acceptance of the new fleet.

K9.3 Rolling Stock Maintenance

In determining the rolling stock maintenance depot approach, the following factors are being considered:

Operational 1. Fleet size and configuration (including potential futureproofing)

2. Operational diagram starts in morning 3. Overnight servicing and stabling requirements 4. Balancing of diagrams peak and off-peak 5. Mix of stock with different diagram mileages and maintenance cycles

Train 6. Maintenance strategy (use of train intelligence, diagnostics, automation) 7. Maintenance requirements (regular / longer term) 8. Individual site facilities

Geographic 9. Minimum depot footprint size whilst assessing future potential for growth10. Location possibilities and associated accessibility (Day 1 and future) 11. Resource / skills availability 12. Operational staff co-location 13. Sustainability effects

K9.3.1 Depot requirements

The following high-level depot requirements have been determined for the anticipated fleet size:

• One main maintenance depot is required with provision for a wide range of activities ranging from basic stabling to heavy works

• To point of stabling, the depot shall be within 10 minutes travelling time of the HS2 route (preferably adjacent)

• The depot shall be located within the West Midlands (convenient for both HS2 captive and classic compatible services; skills availability and suitable potential sites exist)

• The minimum depot footprint shall be assumed as 1.8km long and 0.5km wide based on, but not restricted to, one end entry

• The depot shall be rail accessible to GC gauge, 400m long trains • The depot will require good road access and connectivity to arterial routes for the delivery of

spare parts and consumables • The depot should not be located in a noise sensitive area (most work will be undertaken

overnight)

See Appendix A for a more detailed depot specification.

K9.3.2 Maintenance regime

The new depot will undertake rolling stock inspection, repair, cleaning, light and heavy maintenance, re-watering and replenishing of consumables. A typical scheduled maintenance pattern for a high speed train is shown in Appendix B1. By the time the HS2 fleet is introduced, it is anticipated that vehicle maintenance regimes will be better informed by vehicle diagnostics; it is expected that the maintenance regime shown is therefore a worst case scenario. Using this maintenance regime and an assumed trainset usage of 400,000km per year, the depot workload is detailed in Appendix B2;



calculations to convert the workload to ‘pitted road’ occupancy and usage will be used to validate the footprint size.

The maintenance patterns and flow through the depot will also be used to ensure sufficient capacity remains to move trains around the depot to and prevent ‘grid lock’ both for day 1 and futureproofing.

K9.3.3 Potential Depot Locations

Any viable option must either be on HS2 or have its own purpose built link from HS2 to it because of the need to run GC gauge trains into the depot. A number of potential locations in the West Midlands area have been considered:

Location Comments Retain? Washwood Heath, Birmingham

Sufficient space. Site used as train works previously. At grade rail access dependent upon ongoing re-design of Water Orton corridor (this section was initially proposed as elevated). Potential noise impacts on residents to the south east. Floodplain issues to address. Good road access.

Yes

Bordesley, Birmingham

Site used as train / goods yard but too small. No

Landor / Lawley St Freightliner depot

Existing busy Freightliner depot in central Birmingham, highly unlikely to become available.

No

Tyseley Current and former goods yard / stabling facility; site too small. No Elmdon Current Land Rover site - availability for future depot? Size acceptable, good road access

and skills base. Technically challenging rail access link from the east through green belt (which was refused approval previously).

Yes (but looking unlikely)

Longbridge Mothballed Rover works site, sufficient space; but too far away from HS2 (10km south west of central Birmingham).

No

Greenfield sites adjacent to HS2

Potential locations are entirely dependent upon the routes remaining post-September. Two locations that are undergoing high-level environmental consideration are around Middleton and Berkswell. Others may emerge.

Yes

See Appendix C for a map indicating potential depot locations.

K9.3.4 Evaluation of Potential Depot Locations

The choice of depot location will be heavily driven by the preferred HS2 routes identified at the end of September. In the meantime, initial environmental evaluation is being undertaken for the above retained sites. During October, stakeholder meetings will be undertaken, any other candidate locations will be identified and all sites meeting the high-level requirements specified in section 3.1 will then be considered further to enable recommendation of the preferred HS2 rolling stock depot location(s). Factors to be evaluated will include:

• Location with respect to the needs of the site – fuelling, CET, proximity to rail access • Road access and connectivity • Rail access and options for direct connection to route and service commencement • Other operational issues – line capacity / conflicting traffic moves • Empty coach movements • Environmental considerations including past use of the land • Ground conditions and topography • Space required / available including suitable storage • Ownership – freehold / lease • Security of stores, accommodation, vehicles and stabled sets • Economic – multitude of factors • Proximity to suppliers • Availability of power and services suitable for Day 1 and future needs • Resourcing – labour (skills, availability) • Long term expansion potential without disturbance to established areas of the depot / access



It is estimated that circa 300 people will be employed at the new depot.

K9.3.5 Depot Cost Estimate

At this stage, an estimate of £400m is included in the HS2 cost model to build the HS2 depot. This is based on the 2006 cost of the Eurostar Temple Mills depot and excludes any construction cost for a link from the depot to HS2. The indicative Eurostar depot layout is shown in Appendix D

The Eurostar model is based on one type of stock being maintained – the HS2 depot will need to flexible enough to cater for two types of stock and specialised spares. Additionally certain activities are not currently envisaged and provided for such as traction fuel storage and attenuation of either effluent discharge or groundwater discharge restrictions.

K9.3.6 Future capacity

It is anticipated that the depot footprint should be able to cater for some further growth in the fleet size – potentially dealing with circa 70 sets (although this figure is subject to validation dependent upon the West Midlands site ultimately selected, the types of sets and associated maintenance regime used).

Another option to provide additional capacity in the future for a larger fleet is to concentrate all heavy maintenance (overhauls) at the West Midlands depot. Residual capacity here would be used for light maintenance / inspections with another smaller light maintenance facility provided subsequently elsewhere on the high speed network away from London. This scenario potentially reduces the amount of empty coaching stock movements and also provides greater operational flexibility for a larger fleet. This approach is still compatible with the overall strategy proposed for the Day 1 high speed fleet in this document.

K9.4 Rolling Stock Stabling

For the captive HS2 sets, operational diagrams will start and finish at both the London and Birmingham ends of the route. Classic compatible set diagrams will also start and finish at London and at a mixture of other locations – e.g. Manchester, Liverpool and Glasgow.

Where feasible, stock will return to the main West Midlands depot for overnight stabling and servicing. The depot is sized accordingly.

A number of sets will need to be stabled overnight in London – the number of sets will be validated during October. Potential stabling locations will be driven by choice of London terminal and approach route, as stabling facilities and access to it will need to be GC-gauge to accommodate the captive HS2 sets in addition to the smaller UK1-gauge classic sets. As a minimum, stabling facilities must have watering facilities; CET emptying facilities and shore supplies are likely to be required; carriage washing and a pitted road for ad hoc inspections would be ideal. London overnight stabling options to be evaluated include stabling in the London terminal station; Euston Carriage Sidings and Wembley.

It is assumed that the classic compatible sets used for the last services of the day to destinations beyond HS2 will remain at these locations and form the first services the following morning. As these sets are UK1-gauge, it is currently assumed that they can either be stabled overnight in the station or at existing stabling facilities (high speed sets will potentially be replacing other services, so capacity should be available).



At this stage, an estimate of £150m is included in the HS2 cost model for stabling facilities at the London end only.

K9.5 Rolling Stock Servicing at Terminal Stations

Consideration will be given to servicing requirements – typically this can cover cleaning, re-stocking for catering and comfort needs, watering, minor fault repairs. Factors affecting servicing include the length of turnaround times, the type of catering offer (if any) and anticipated passenger loadings.



K9.6 Appendix A – Depot Specification

Site footprint:

• Minimum 1.8km long and 0.5km wide based on one end entry1 • Site may need to be ‘slightly’ longer for both end entry or with stand-off stabling to ensure

suitable access / egress from HS2 or other lines of route • Typically there can be some ‘tapering’ effect at either end to the site to accommodate the entry

and exit points, but the curvature of turnouts will be at maximum radii to prevent excessive wear or maintenance

• The footprint also includes provision for accommodation and ancillary buildings, car parking and storage

Layout:

• 8 x 400m tracks within the main shed to allow work on complete coupled trainsets, eliminating the need for trains to be split for maintenance

• Main shed configured to deal with both types of train • Track spacing 6.5m to provide sufficient working space for maintenance staff, tool storage, plant

and equipment • Provision of stabling 5 roads adjoining the maintenance shed for the fleet (including provision of

associated servicing, fuelling & CET capabilities on the stabling roads) • Suitable capacity provision for run through movements to position stock for maintenance or

longer ad hoc servicing due to unplanned faults Facilities:

• 450 m long and 60 m wide covered main maintenance building designed with environmental considerations for economic heating and grey water attenuation / reuse

• Bi-directional carriage washing plant • Sufficient toilet-emptying and water replenishment facilities – potentially on all reception and

stabling roads • Discharge consent and attenuation provision to comply with local drainage network with suitable

recycling as necessary • Automatic wheel and pantograph equipment and download points for onboard telemetry

equipment to assist maintenance scheduling • Bogie drop able to handle two trains simultaneously • Provision for overhead cranes on site, positioned to handle both 200m and 400m trainsets • Signalling and overhead power for all depot lines (all controlled from one control room) • Heavy repair facility plus bogie removal, wheel drop, etc. • Wheel turning facility (minimum requirement 1 lathe per 1200 axles) • Office facilities for depot production control, technical support, drivers signing on, messing etc. • Stores facility with handling automation in storage • Facilities to allow for working of approx 200 or so staff working shifts • Adequate power and water provision to all roads • Suitable road access and delivery point for rail vehicles delivered by road or equipment by low

loader • Waste fluid and hazardous material storage suitably located for proximity of use and disposal

1 It is possible to flex the footprint dimensions by reconfiguring the depot layout e.g. so that the site is shorter and fatter or through provision of stand-off stabling facilities. The over riding parameter is the ability to maintain and move 400m trainsets around and service any vehicle in that set without splitting.



K9.7 Appendix B1 – High Speed Maintenance Service Schedule

Inspection System/Task Mileage Interval

[km]Depot Equipment

neededTime including emerging

work and CET extraction (1 day = 24 hours)

Men/shift Man-hours

I1 Bogie and wheels 4,000 Any pitted road 4hr 6 24I2 Roof mounted equipment 8,000 Roof access 6hr 8 48M1 Majority of on-board equipment 100,000 Main traincare facility 2,3 days 4 224M2 Majority of on-board equipment 400,000 & 120,000 Main traincare facility 4 days 6 576M3 Majority of on-board equipment 800,000 Main traincare facilityR1 First Revision 1,600,000R2 Second Revision 3,200,000Wheel re-profiling 175-200,000Ultrasonic testing 100-200,000

K9.8 Appendix B2 – Estimated Depot Workload

1 2 3 4 5 6 7 8 9 10

400,000 800000 1200000 1600000 2000000 2400000 2800000 3200000 3600000 4000000I1 50 50 50 50 50 50 50 50 50 50I2 50 50 50 50 50 50 50 50 50 50M1 4 4 4 4 4 4 4 4 4 4M2 1 1 1 1 1 1 1 1 1 1M2 revision 0 0 1 0 0 1 0 0 1 0M3 0 1 0 1 0 1 0 1 0 1R1 0 0 0 1 0 0 0 1 0 0R2 0 0 0 0 0 0 0 1 0 0Wheel re-profiling 2 2 2 3 2 2 3 2 2 2Ultrasonic testing 4 4 4 4 4 4 4 4 4 4

No. testsper year

Kms at the end of the yearyear



K9.9 Appendix C – Potential Depot Locations

Train Depot Location

West Midlands KEY Middleton area Washwood Heath Elmdon Berkswell



K9.10 Appendix D – Indicative Plan of Temple Mills (HS1 Eurostar Depot)

ROUTE ENGINEERING STUDY FINAL REPORT: A REPORT FOR HS2

Documents

line of route

station iver terminus

terminus station terminal

introduction euston

london station euston

introduction west ruislip

west midlands approach

west of amersham amersham