Combined AWS and TPWS Trainborne Eqpt.

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Combined Manual for AWS and TPWS Trainborne Equipment

Page 2 of 179 RAIL SAFETY AND STANDARDS BOARD GM/GN2169 Issue One: April 2007

Issue Record Issue Date Comments

One 7 April 2007 Original document Replaces MT/169 Automatic Warning System Manual and Instructions

Superseded documents This Railway Group Guidance Note does not supersede any other Railway Group document. However, it replaces MT/169 Automatic Warning System Manual and Instructions, originally published by British Rail in November 1980.

Supply Controlled and uncontrolled copies of this Railway Group Guidance Note may be obtained from the Corporate Communications Department, Rail Safety and Standards Board, Evergreen House, 160 Euston Road, London NW1 2DX, telephone 020 7904 7518 or e-mail [email protected]. Railway Group Standards and associated documents can also be viewed at www.rgsonline.co.uk.



RAIL SAFETY AND STANDARDS BOARD Page 3 of 179 GM/GN2169 Issue One: April 2007

Contents Section Description Page

Part 1 Introduction 6 1.1 Purpose of this document 6 1.2 Background 6 1.3 Copyright 6 1.4 Approval and authorisation of this document 7

Part 2 Overview of AWS and TPWS systems 8 2.1 Overview of AWS system 8 2.2 General operation of AWS trainborne equipment 12 2.3 Overview of TPWS system 14 2.4 General operation of TPWS trainborne equipment 19 2.5 Trainborne equipment – general description 21 2.6 Trainborne equipment – manufacturers’ products (Howells) 30 2.7 Trainborne equipment – manufacturers’ products (STS Signals Ltd) 33 2.8 Trainborne equipment – manufacturers’ products (Thales) 34 2.9 Trainborne equipment – manufacturers’ products (Unipart Rail) 43 2.10 Data recording requirements 49 2.11 Configuration management and equipment compatibility 51

Part 3 Guidance on maintenance and fault finding 70 3.1 Maintenance requirements 70 3.2 AWS depot test equipments 72 3.3 AWS test equipment 75 3.4 TPWS test equipment 78 3.5 Fault and failure management 80

Appendices 97 Appendix A Useful contacts 97 Appendix B Typical AWS/TPWS electrical installation on single cab vehicle 98 Appendix C Typical AWS/TPWS electrical installation on dual cab vehicle 99 Appendix D STS AWS/TPWS vehicle interface details 100 Appendix E Thales AWS/TPWS vehicle interface details 101 Appendix F Unipart Rail AWS/TPWS vehicle interface details 109 Appendix G Optimum overhaul periodicities for AWS/TPWS equipment 122 Appendix H Form RT3185 reporting AWS/TPWS failure or irregularity 127 Appendix I Form RT3188 activation of TPWS 129 Appendix J Component tracking application form 130 Appendix K Component tracking information sheet 131 Appendix L Typical locomotive fault diagnosis procedure 132 Appendix M AWS testing using a hand-held permanent magnet 136 Appendix N AWS testing using STS TY287 test equipment 138 Appendix O AWS testing using Unipart Rail test equipment 146 Appendix P Fore and aft positions for AWS receivers 149 Appendix Q AWS/TPWS testing using Thales depot test unit (DTU) 156 Appendix R TPWS testing using Unipart Rail hand-held signal generator 160 Appendix S TPWS testing using Thales train test unit 165 Appendix T Typical AWS/TPWS fault finding test sheet 173 Appendix U Typical AWS/TPWS wrong-side failure report form 174 Appendix V Typical labels for defective AWS/TPWS equipment 175

Definitions 176

References 179




Tables Table 1 Functions of the control panel indicators and pushbutton 38 Table 2 Thales control unit train data recorder outputs 50 Table 3 Unipart Rail control unit train data recorder outputs 50 Table 4 Howells Railway Products Ltd 53 Table 5 STS Signals Ltd 55 Table 6 Thales UK Limited, Land and Joint Systems 56 Table 7 Unipart Rail 64 Table 8 AWS track magnet scenarios 76 Table 9 AWS/TPWS fault codes 83 Table 10 Common human error type faults 93 Table 11 Common system faults 94 Table 12 Common trainborne equipment faults 96

Figures Figure 1 Typical track-mounted AWS magnet 9 Figure 2 Layout of track-mounted AWS magnet 10 Figure 3 AWS trainborne equipment state diagram 12 Figure 4 Typical TPWS trackside sub-system layout 16 Figure 5 TPWS train stop system 16 Figure 6 TPWS overspeed sensor system 16 Figure 7 TPWS buffer stop mini-loop 17 Figure 8 TPWS trainborne sub-system state diagram 19 Figure 9 Typical AWS/TPWS trainborne sub-system 22 Figure 10 Typical TPWS control unit 23 Figure 11 Typical AWS receiver 23 Figure 12 Typical AWS receiver mounted on bogie 24 Figure 13 Typical AWS twin-lightweight receiver 24 Figure 14 Typical AWS and alarm and indicator unit 25 Figure 15 Typical AWS sunflower 25 Figure 16 Typical TPWS aerial 26 Figure 17 Typical TPWS driver’s control panel 26 Figure 18 Typical reset/acknowledge button 27 Figure 19 Typical PSU 28 Figure 20 Typical full isolation switch 29 Figure 21 Typical TPWS temporary isolation switch 30 Figure 22 Howells Relay unit and relay junction box 30 Figure 23 Howells AWS receiver and junction box 31 Figure 24 Howells EP valve 31 Figure 25 Howells electric trembler AWS bell 31 Figure 26 Howells bulkhead mounting and flush mounting AWS indicators 32 Figure 27 Howells traditional desk-mounted dome AWS reset pushbutton 32 Figure 28 Howells AWS isolation switch 33 Figure 29 STS ‘twin-lightweight’ AWS receiver 34 Figure 30 Thales control unit 36 Figure 31 Thales AWS/TPWS PSU 36 Figure 32 Thales Mark II and III control unit terminal boxes 37 Figure 33 Thales AWS alarm and indicator unit 38 Figure 34 Thales TPWS driver’s control panel 39 Figure 35 Thales combined AWS/TPWS reset/acknowledgement pushbutton 39 Figure 36 Thales electronic solid-state AWS receiver 40 Figure 37 Thales composite TPWS aerial and harness 41 Figure 38 Thales aerial deflector in the shape of a dome 41 Figure 39 Thales combined TPWS aerial with electronic AWS receiver 42 Figure 40 Thales underframe mounted junction boxes 42 Figure 41 Thales TPWS temporary isolation switch 43 Figure 42 Unipart Rail combined AWS and TPWS control unit 44 Figure 43 Unipart Rail PSU 45 Figure 44 Unipart Rail electronic solid-state AWS receiver 45




Figure 45 Unipart Rail TPWS aerial 46 Figure 46 Unipart Rail TPWS aerial cable 46 Figure 47 Unipart Rail driver’s control panel 47 Figure 48 Unipart Rail ‘harsh environment’ driver’s control panel 47 Figure 49 Unipart Rail TPWS aerial switching unit 48 Figure 50 Unipart Rail full isolation switch 48 Figure 51 Unipart Rail TPWS temporary isolation switch 49 Figure 52 Unipart Rail hand-held AWS permanent test magnet 70 Figure 53 Unipart Rail AWS depot track-mounted permanent test magnet 70 Figure 54 Vortok standard strength depot test magnet on fixed mount 71 Figure 55 Vortok extra strength depot test magnet on moveable mount 71 Figure 56 Checking the height of magnet 71 Figure 57 STS TY287 AWS tester 76 Figure 58 STS flux generator positioned under a vehicle’s AWS receiver 76 Figure 59 Thales DTU 77 Figure 60 Unipart Rail hand-held combined AWS/TPWS test equipment 78 Figure 61 Thales DTU 78 Figure 62 Thales TTU unit kit 79 Figure 63 Thales TTU 79 Figure 64 Thales TTU track-mounted transmitter loop 80 Figure 65 Unipart Rail hand-held combined AWS/TPWS test box 80 Figure 66 AWS/TPWS right side failure investigation process 85 Figure 67 AWS wrong side failure investigation process 86 Figure 68 Example train data recorder output 90 Figure 69 Combined AWS/TPWS fault finding guide 91 Figure 70 Combined AWS/TPWS system fault finding flowchart 92 Figure 71 Thales Depot Test Unit (DTU) front panel 153 Figure 72 Typical trainborne equipment set-up for Thales TTU operation 162




Part 1 Introduction 1.1 Purpose of this document

1.1.1 This document sets out to provide good practice information on the maintenance, testing and fault finding procedures associated with the Automatic Warning System (AWS) and Train Protection and Warning System (TPWS) trainborne equipment. It is intended to assist in maintaining the reliability of these essential safety systems at an appropriate level.

1.2 Background 1.2.1 AWS was initially introduced to the railway on the London Tilbury and Southend

Railway and the Great Western Railway before being implemented as the national warning system throughout the mainline passenger railway network during the 1950s and onwards. AWS has since been the main safety system for drivers to aid avoiding serious incidents and accidents and is a vital part of the safety of the rail network. The original concept of AWS was to provide the driver with an audible and visual indication reflecting whether the approaching caution signal aspect was clear or not. Since then, its use has been broadened to include an alert to drivers of approaching hazards, for example speed restrictions, for appropriate action to be taken.

1.2.2 Following the decision taken in 1994 not to fit an automatic train protection system to the national network, the railway authorities agreed to apply an alternative train protection system. The TPWS was therefore conceived as such a system, being an overlay to the existing AWS system functionality rather than a replacement. In 1999, the Government mandated, by Regulation, the fitment of an advanced system of train control to the network and rolling stock, of which TPWS met the basic requirements. The concept of TPWS is to apply the brake to mitigate a signal passed at danger (SPAD) rather than to prevent a SPAD. By doing this at, or as the train approaches the signal at danger, the distance travelled will be reduced as will any collision speed. A few SPADs may be prevented.

1.2.3 In order to facilitate a rapid and more efficient roll-out of TPWS on rolling stock, electronic control units have been developed combining the logic functions of the existing AWS system and the new TPWS system. The new control unit replaces the old AWS relay unit, using the existing AWS peripheral equipment wherever practicable. Thus, whilst the two systems are functionally separate, they may share a common control unit and common inputs and outputs, such as the power supply, isolation switch and brake demand relays.

1.2.4 The introduction of TPWS incurred a number of operating and equipment reliability problems which are gradually being addressed. This document has been developed to aid maintenance personnel in improving the overall reliability of the AWS and TPWS trainborne sub-system, by sharing good practice and experience that has emerged from the reliability growth process.

1.3 Copyright 1.3.1 Copyright in the Railway Group documents is owned by Rail Safety and

Standards Board Limited. All rights are hereby reserved. No Railway Group document (in whole or in part) may be reproduced, stored in a retrieval system, or transmitted, in any form or means, without the prior written permission of Rail Safety and Standards Board Limited, or as expressly permitted by law.

1.3.2 Rail Safety and Standards Board members are granted copyright licence in accordance with the Constitution Agreement relating to Rail Safety and Standards Board Limited.




1.3.3 In circumstances where Rail Safety and Standards Board Limited has granted a particular person or organisation permission to copy extracts from Railway Group documents, Rail Safety and Standards Board Limited accepts no responsibility for, and excludes all liability in connection with, the use of such extracts, or any claims arising therefrom. This disclaimer applies to all forms of media in which extracts from Railway Group Standards may be reproduced.

1.3.4 Copyright restrictions apply to the use of certain elements of this document, where information from the suppliers acknowledged below is concerned and permission should be sought from RSSB when the arrangements set out in 1.3.2 do not apply.

1.3.5 RSSB would like to formally acknowledge the contribution of the following suppliers when compiling this document:

Howells Railway Products Ltd STS Signals Ltd Thales UK Limited, Land and Joint Systems (herein referred to as ‘Thales’) Unipart Rail

1.4 Approval and authorisation of this document The content of this document was approved by:

Rolling Stock Standards Committee on 24 November 2006.

This document was authorised by RSSB on 15 February 2007




Part 2 Overview of AWS and TPWS systems 2.1 Overview of the AWS system 2.1.1 Background

2.1.1.1 British Rail implemented a standard AWS system nationally to aid the driver in determining whether an approaching signal was clear or not. It has also been used to warn the driver of other potentially hazardous situations, such as severe reductions in speed, the approach to open level crossings and temporary or emergency speed restrictions.

2.1.1.2 The purpose of AWS is to give drivers an in-cab warning of the approach to a potentially hazardous situation such that the driver may take appropriate action to stop or slow the train down. Should the driver fail to acknowledge the AWS warning, then the AWS system will intervene and apply the train brakes to stop the train. The system is designed to provide the warning, and consequent brake application, at a suitable braking distance from the stop signal or other hazard. It should be noted that the addition of AWS does not relieve the driver of his/her duty to observe and obey lineside signals.

2.1.1.3 The AWS system comprises a trackside sub-system and a trainborne sub-system. These are described in outline below. The mandatory requirements for the AWS system are contained in GE/RT8035.

2.1.2 General system operation 2.1.2.1 In the case of signals, as the train approaches an AWS fitted signal it passes over

track-mounted magnets normally located approximately 180 m before the signal. The trainborne receiver at the front of the train senses the south pole from the permanent magnet and the north pole from the electromagnet, if energised. The receiver sends this information to the control unit which processes the magnet states and controls the AWS peripheral equipment and brake demand in response.

2.1.2.2 If the signal is displaying a clear aspect (green aspect or semaphore distant at ‘off’) then the electromagnet will be energised and the logic unit will be presented with a south pole detected immediately followed by a north pole. The logic unit will command the AWS ‘clear’ audible tone to be sounded in the cab (bell or electronic chime) and the AWS visual sunflower indicator to show ‘all black’. The driver does not have to take any specific action as a result other than to note that the AWS indications given correspond with the signal aspect (in case of AWS wrong side failure). The sunflower indicator will retain this indication as a reminder for the driver that the last signal was displaying a clear aspect.

2.1.2.3 If the signal is displaying a caution aspect (two yellows or one yellow on a colour light signal or a semaphore distant signal at ‘on’) or a stop aspect (red aspect on a colour light signal or semaphore home signal at ‘on’) then the electromagnet will not be energised and the control unit will be presented with only a south pole detected (note this configuration also provides ‘fail safe’ operation should the trackside power supply or the electromagnet fail). The control unit will command the AWS ‘caution’ audible tone to be sounded in the cab (horn or electronic tone) and the AWS visual indicator initially to show ‘all black’. The driver must respond to the caution indication within a prescribed short time period to prevent an automatic brake application ensuing. The driver does this by pressing and releasing the AWS reset pushbutton (sometimes known as the AWS acknowledge pushbutton) at which point the AWS visual indicator shows a ‘yellow/black’ sunflower indication reminding the driver that they have acknowledged the caution indication and prevented AWS from taking control of the train. The sunflower indicator will retain this indication as a reminder that the driver has taken control of the train brake.




2.1.2.4 If the driver does not respond to the AWS caution indication within the prescribed time period then the AWS will apply the train brakes and bring the train to a stand. On the former ‘British Rail’ AWS equipment types, the driver was able to release the automatic brake application at any time by pressing and releasing the reset button, but on the modern electronic control units the brake application will be maintained for at least 59 seconds after the brake application has been made.

2.1.2.5 In the case of AWS provided for speed restrictions and at open level crossings locally monitored by the driver, only the AWS permanent magnet is provided (south pole) therefore the trainborne AWS will always receive a cautionary indication which will require acknowledging by the driver in the same manner as at a signal not showing a clear aspect. The AWS magnet is located 180 m on the approach to the speed restriction advanced warning indicator, which itself is located at a suitable braking distance from the speed restriction commencement point.

2.1.2.6 An AWS permanent magnet is also located on the exit(s) from maintenance depots. In this case the driver is required not to acknowledge the AWS caution indication and to allow the AWS to apply the brakes to test that the system functions from end-to-end. Various equipment types conduct self-tests at the start and/or during the journey to monitor the correct functionality of the AWS trainborne sub-system.

2.1.2.7 Procedures exist, as set out in the Rule Book Module TW5 for the driver to respond to AWS failures. The driver can isolate a defective AWS system by operating the AWS isolation switch in the driving cab and will be required to follow the Rule Book requirements accordingly. It should be noted that isolating the AWS will also normally isolate the TPWS equipment where a combined electronic control unit is used.

2.1.3 Trackside sub-system 2.1.3.1 The trackside AWS sub-system comprises equipment mounted on the track

centre line and trackside mounted control equipment connected to the signalling system.

2.1.3.2 The track-mounted equipment comprises a permanent magnet with its axis mounted in the vertical plane with its south pole facing uppermost, and an electromagnet with its axis mounted in the vertical plane with its north pole facing uppermost (Figures 1 and 2). The south pole is always arranged to be the first magnet seen by the train and the electromagnet is mounted immediately adjacent to the permanent magnet along the track centre line.

Figure 1 Typical track-mounted AWS magnet




Figure 2 Layout of track-mounted AWS magnet

2.1.3.3 The south pole of the permanent magnet when presented alone provides the AWS warning given to the driver, hence at situations where only a warning has to be provided, for example approaching a severe speed restriction, temporary or emergency speed restriction or open level crossing, then only a permanent magnet is required and no electromagnet or connections to a power supply or the signalling system are necessary. The north pole of the electromagnet when presented after the south pole, provides the driver with the ‘clear’ indication at green signals, and is switched on and off via the signal control circuitry. There is no designed state that requires application of the electromagnet north pole alone.

2.1.3.4 The top surface of the magnet is nominally mounted at rail level (+/- 12 mm) and is protected by a ‘running on’ ramp in the normal direction of travel to minimise the likelihood of damage from items hanging or dragged by passing vehicles.

2.1.3.5 GE/RT8035, GK/RT0038 and GI/RT7011 describe the situations where AWS is to be provided, and the configuration of magnets and their control. Fundamentally, AWS is applied at all semaphore distant signals and to colour light running signals capable of displaying one yellow, two yellows or a red aspect. AWS permanent magnets are also fitted to the exits of maintenance depots; the approach to reductions in permissible speed where the reduction in speed is at least 33%; the approach to temporary and emergency reductions in speed; and the approach to open crossings locally monitored by the driver. There are ‘gaps’ in trackside sub-system coverage such as in complex junction areas, and these are indicated by lineside signs.

2.1.3.6 In addition, AWS has been applied at some signals as a SPAD mitigation to sound the AWS warning to the driver if the train passes certain high risk signals at danger (known as a SPAD magnet).

2.1.3.7 The permanent and electromagnets are provided in two strengths:

a) Standard strength magnets used in all areas except dc electrified line areas (traditionally painted yellow).

b) Extra strength magnets for use on dc electrified line areas (traditionally painted green).

2.1.3.8 Other forms of track magnets are available in these two strengths, including permanently installed depot exit test magnets, portable permanent magnets used for temporary and emergency speed reductions and ‘suppressor’ electromagnets used to suppress permanent magnets when they are not required to apply to a train movement (for example on a bi-directionally signalled line).




2.1.3.9 The track-mounted magnets are mounted an appropriate distance on the approach side of the signal (or speed reduction indicator) such that the in-cab indications are provided to the driver in time to see the signal aspect or lineside sign that the magnet(s) applies to.

2.1.4 Trainborne sub-system 2.1.4.1 The AWS trainborne sub-system comprises a number of AWS components and a

number of variations depending on the type of vehicle and the equipment supplier. Most current installations of AWS are combined with TPWS and share a number of common components (TPWS function, operation and equipment are detailed further in sections 2.3 and 2.4. AWS and TPWS equipment are described in section 2.5).

2.1.4.2 In conjunction with the basic AWS equipment, additional equipment is required to integrate AWS with the vehicle brake and control systems. There are two main variations in the additional equipment fitted to the majority of traction and rolling stock, energise-to-release electric brakes and locomotive systems. Appendices B and C illustrate a typical AWS/TPWS electrical installation on a single cab and dual cab vehicles.




2.2 General operation of AWS trainborne equipment 2.2.1 This section of the guidance note provides an overview of the general operation

of the trainborne element of AWS. It describes the operation of the trainborne sub-system from the receiver detecting the magnets, the response of the control equipment and driver’s interface, through to the brake interface. Understanding the exact nature of these states and the entry and exit conditions may help during fault finding particularly when analysing the outputs of train data recorders.

2.2.2 Figure 3 is extracted from GE/RT8035 and shows the normal system response states (note GE/RT8035 section B12 describes each functional state and the entry and exit criteria in detail):

Figure 3 AWS trainborne equipment state diagram

2.2.3 It should be noted that the cancellation of an AWS brake demand, following the activation of the acknowledgement device by the driver, is subject to a time delay of at least 59 seconds.

OPERATIONAL READY STATE

South pole of track magnet detected

PRIMED STATE

North pole of electromagnet detected within

initial delay period?

RESTRICTIVE RESPONSE STATE

CLEAR SIGNAL RESPONSE STATE

RESTRICTIVE ACKNOWLEDGEMENT STATE

Driver operates caution

acknowledgement device within caution

acknowledgement period?

RESTRICTIVE NON-ACKNOWLEDGEMENT STATE

AWS brake demand

Driver operates caution acknowledgement

device ?

AWS brake demand continues and brings the vehicle to a stop

Brake demand cancelled

No

Yes

Yes

No

No

Yes




2.2.4 Power to the AWS trainborne sub-system is normally controlled by the cab master switch, such that the control unit only receives power when a master key has been inserted into the master controller and the neutral/engine only position has been selected. On dual cab vehicles such as locomotives fitted with a change end switch in the cab, the change end switch must be put to ‘on’ to allow the control unit to power up.

2.2.5 When power is applied to the AWS trainborne sub-system, the control unit cycles through an interactive self-test process to determine whether it is able to function correctly. Different trainborne manufacturers systems approach this in a slightly different way but the end result is to provide confidence that the system is fit to enter service. GE/RT8035 requires that the AWS trainborne equipment have a built-in self-test routine, which tests that the audible and visual indications operate when required and that an AWS brake demand can be requested when required. (Note that it is not mandatory that the test routine proves that the receiver is capable of detecting magnetic fields from test magnets or that the brakes are actually applied following an AWS brake demand. However both of these will be accomplished using the trackside equipment mounted on the exit roads from maintenance depots.

2.2.6 During the self-test routine the control unit will drive the indicator first to ‘yellow/black’, then to the ‘all black’ state and sound the audible warning tone proving that it can output these indications. The driver is required to note that the brakes are applied (in practice the brakes will be applied before TPWS system power up) after which the driver can silence the audible warning tone and release the brake demand by pressing and releasing the reset pushbutton. This action not only tests the reset function but should also result in the in-cab AWS indicator displaying a ‘yellow/black’ visual indication.

2.2.7 When initialising a cab, including when changing ends on a dual cab vehicle, the above self-test is required to be initiated (normally automatically). Once, the self-test routine has been successfully concluded then the AWS trainborne sub-system moves to the operational ready state. If the self-test fails then the AWS system is required to annunciate this to the driver. This will normally be achieved by AWS holding a brake application and/or sounding the warning continuously, depending on the manufacturers design.

2.2.8 In the operational ready state the AWS trainborne sub-system is set to detect AWS track magnets and to respond accordingly. The sunflower indicator will remain showing ‘yellow/black’ as its last state following the self-test routine.

2.2.9 As soon as the receiver detects the south pole of an AWS permanent magnet, the system enters the primed state. Immediately on entry to this state, the sunflower indicator will change to ‘all black’ and the control unit will wait a pre-defined short period (the initial delay period) of 1 second (+0.0/-0.1 seconds) in order to allow the AWS receiver to detect the north pole of the electromagnet if the associated signal is clear. The spacing of the track magnets and the nominal 1 second delay period will allow trains travelling at approximately 4 mph and above to respond to a valid green signal, below this speed the receiver will not pass over the magnets within the nominal 1 second period and a caution response may follow despite the signal displaying a green aspect.

2.2.10 If the south pole is immediately followed by a north pole within the initial delay period, then the AWS trainborne sub-system will enter the clear signal response state. In this state, the alarm and indicator unit will sound the ‘clear’ indication for between 0.5 and 1.5 seconds and retain the sunflower indicator in the ‘all black’ state. The AWS trainborne sub-system then returns to the operational ready state.




2.2.11 If only a south pole is detected within the initial delay period, for example the signal is not displaying a clear (green) aspect or the AWS trackside sub-system is associated with a speed reduction, then the system enters the restrictive response state. In this state, the alarm and indicator unit sounds the audible warning tone. If the driver presses and releases the reset pushbutton within a period of 2 seconds (+/-0.25 seconds)1, then the AWS trainborne sub-system enters the restrictive acknowledge state. If the driver does not press and release the reset pushbutton within this time then the AWS trainborne sub-system enters the restrictive non-acknowledge state.

2.2.12 Note: unlike the older relay based systems, pressing the reset pushbutton before the new electronic trainborne equipment enters the restrictive response state will not allow the caution indication to be acknowledged, thus avoiding drivers anticipating the caution indication before it is actually received. In practice this has led to a number of unwarranted brake demands as drivers adjust to this difference with the new electronic AWS control units.

2.2.13 In the restrictive acknowledge state, the sunflower indicator will change to ‘yellow/black’ and the audible warning tone will be silenced. The sub-system then returns to the operational ready state.

2.2.14 In the restrictive non-acknowledge state the sunflower indicator is maintained at ‘all black’ and the audible warning tone is continuously sounded. In addition, the control unit demands a brake application. Normally this will be an emergency brake application, but in some vehicles, for example some locomotives, this may be a full service brake application. The sub-system will remain in this state until the driver presses the reset pushbutton, when it will move to the restrictive acknowledge state (where the visual indicator will change to ‘yellow/black’, the warning tone will be silenced and the brake demand will be cancelled after at least 59 seconds have elapsed from when the brakes were applied2).

2.2.15 One further state exists, that of system isolation. In this state, entered by operating the isolation switch, any existing brake demand is cancelled, the audible indications are silenced and power is removed from the AWS control unit.

2.3 Overview of TPWS system 2.3.1 Introduction

2.3.1.1 AWS is unable to prevent all SPADs or over-speeding related accidents as it can be overridden by the driver. Therefore, TPWS was developed to enhance train protection under these circumstances by applying the train brakes automatically if a train passes a signal at danger or if the train approaches a signal at danger such that a SPAD is highly likely. In addition, TPWS has been applied to other locations where a potentially hazardous over-speeding risks a derailment or collision, such as at certain speed reductions and on the approach to terminal passenger platform buffer stops.

2.3.1.2 The TPWS system comprises a trackside sub-system and a trainborne sub-system. These are described in outline below.

2.3.1.3 The mandatory requirements for the TPWS system are contained in GE/RT8030.

2.3.2 Basic system operation 2.3.2.1 In the case of signals, the track-mounted TPWS transmitter loops are only active

when the associated signal is displaying a stop aspect (red aspect on a colour light signal or semaphore signal at ‘on’). In the case of TPWS fitted at other

1 Where the maximum speed that the train is capable of is less than 100 mph then the caution acknowledgement period may be up to a maximum of 2.7 seconds (+/-50 ms). 2 The older BR generation of AWS equipment did not retain the brake application after the acknowledgement push button had been pressed.




locations, for example speed restrictions and buffer stops, the transmitter loops are always energised as the train passes over them.

2.3.2.2 Every signal selected for TPWS fitment will have a train stop system (TSS) located at the foot of the signal, and most, but not all, will also have an overspeed sensor system (OSS). Some signals may have more than one OSS depending on how many routes there are approaching the signal, and whether it qualifies for TPWS+.

2.3.2.3 As the train approaches a TPWS fitted signal at danger, or other specified locations fitted with TPWS, it passes over the track-mounted OSS transmitter loops. An OSS has a ‘set speed’ which is dependent on the spacing between the first loop (arming loop) and the second loop (trigger loop). The trainborne receiver (TPWS aerial) at the front of the train senses the arming loop frequency and sends this information to the control unit. The control unit then starts a timer which is set to one of two settings, 974 ms for trains with passenger brake performance and 1218 ms for trains with goods brake performance3. A TPWS brake demand (automatic emergency brake) will occur if the timer is still running when the control unit detects the trigger loop frequency. This means that the train is travelling at or above the set speed. If the train is travelling below the set speed then the trigger loop will be detected by the control unit after the OSS timer elapses and no brake demand will ensue.

2.3.2.4 If the train passes a TPWS fitted signal at danger then it will encounter the TSS which will immediately demand an automatic emergency brake application.

2.3.2.5 Whenever a TPWS brake demand is made, the driver’s display/control panel will indicate this by a flashing illuminated lamp, which must be acknowledged by the driver pressing the TPWS acknowledge pushbutton (normally the AWS reset pushbutton) before the brake can be released. A brake application is normally made for one minute provided it has been acknowledged, thus there are no speed inputs to the TPWS trainborne sub-system. When the acknowledge pushbutton has been pressed, the brake demand flashing indicator changes to a steady state until the time-out period elapses.

2.3.2.6 Provision is made for the driver to pass a TPWS fitted signal at danger with authority, without invoking a TPWS brake demand. In this case, the driver can press the train stop override (TSO) function on the display/control panel which will invoke a timed period in which to pass the active TSS. The time period is configurable at installation, being either 20 seconds (generally for passenger trains) or 60 seconds (generally for slower accelerating freight trains). The TSO allows the train to pass one signal only without a brake demand occurring.

2.3.2.7 If a series of signals are to be passed at danger, for example in an engineering possession, then the temporary isolation switch can be used to isolate the trainborne sub-system to avoid repetitive applications of the TSO.

2.3.2.8 Various procedures exist, as set out in Rule Book Module TW5, for the driver to respond to TPWS failures. The driver can isolate a defective TPWS system by operating the TPWS temporary isolation switch in the driving cab and will be required to follow the Rule Book requirements accordingly. If operating this switch does not release the brakes and allows the train to continue, the driver can operate the full isolation switch noting that this will isolate the AWS trainborne sub-system as well.

3 For locomotives fitted with both passenger and goods brake timing systems, the correct TPWS timer is normally selected automatically when the passenger/goods brake changeover switch is operated.




2.3.3 Trackside sub-system equipment 2.3.3.1 The track-mounted TPWS equipment consists of pairs of track-mounted

transmitter loops forming either a TSS or OSS. Each pair of loops is fed from a pair of trackside TPWS control modules, connected by lineside cabling, which itself is interfaced to the signalling system to derive power supplies and control commands. The TPWS control equipment is mounted at the trackside. Figure 4 shows diagrammatically a typical trackside TPWS system layout, Figure 5 a typical TSS and Figure 6 a typical OSS.

Figure 4 Typical TPWS trackside sub-system layout

Figure 5 Typical TPWS TSS

Figure 6 Typical TPWS OSS




2.3.3.2 Each set of transmitter loops emits a defined pair of frequencies to passing trains when switched on. A TSS or OSS is configured to operate in one direction of travel only, and separate pairs of frequencies are employed for each direction on a bi-directionally signalled or single line. However, the frequencies nominally selected for the ‘normal’ direction of travel are permitted to be used on lines for the ‘opposite’ direction of travel, particularly in complex areas.

2.3.3.3 Each signal selected for TPWS fitment (generally signals protecting a point of conflict) will have a TSS and may have an OSS depending on the speed of approaching trains. The TSS (and OSS if fitted) will be switched on only when the signal is displaying a stop aspect (red aspect on a colour light signal and semaphore home signal ‘on’). However, some signals with subsidiary aspects may be arranged to suppress only the TSS (and maintain the OSS in an active state) when the subsidiary signal aspect clears.

2.3.3.4 Normally a train will only pass over a maximum of one OSS for each signal, although there may be more than one OSS if there is more than one approach to the signal. However, an additional OSS may also be located in rear of the standard signal OSS for signals which are approached at very high speed to provide two checks of approaching speed where braking distances are longer. This is known as TPWS+ (TPWS plus).

2.3.3.5 OSS at buffer stops and speed restrictions are permanently switched on (although some remote installations might contain a battery power supply which is switched on by an approaching train). The transmitter loops at buffer stops are of a smaller design than for signals and speed restrictions due to adverse interactions with standard loops with trains travelling at low speeds (Figure 7).

Figure 7 Typical TPWS buffer stop mini-loop

2.3.4 Trainborne equipment 2.3.4.1 The trainborne TPWS sub-system comprises a number of TPWS components

and there are a few variations in TPWS components depending on the type of vehicle and the equipment manufacturer. These are described further in section 2.5. Most current installations of TPWS are combined with the automatic warning system and share a number of common components. AWS function, operation and equipment are detailed in sections 2.1, 2.2 and 2.5.

2.3.4.2 In conjunction with the basic TPWS equipment described in later sections, additional equipment is required to integrate TPWS with the vehicle brake and control systems.

2.3.4.3 Certain vehicle types are exempt from having TPWS. These are detailed in GE/RT8030 as:

a) Vehicles that operate solely within engineering possessions.

b) Locomotives used exclusively for shunting purposes.




c) Where an alternative train protection system is fitted to both trains and infrastructure.

2.3.4.4 There are also circumstances where TPWS need not be active, however the sub-system is still required to be fitted to enable the vehicles to work under normal circumstances.

2.3.4.5 GE/RT8026 permits the suppression of the TPWS trainborne sub-system from operation once an alternative train control/signalling/protection system is in operation. For example, it is permitted to suppress TPWS where a train is fitted with an operational Automatic Train Protection (ATP) system when running on an ATP fitted line.

2.3.4.6 At the time this issue of the Guidance Note is published, operational suppression arrangements will not exist for the Great Western or Chiltern Lines ATP systems, or for trip cock fitted trains in mechanical train stop fitted areas. However, operational suppression of TPWS does occur with the Tilt Authority and Speed Supervision (TASS) system which is able to override TPWS brake interventions at other locations where tilting trains are permitted to run at a higher speed than conventional non-tilting trains.




2.4 General operation of TPWS trainborne equipment 2.4.1 This section provides an overview of the basic operation of the TPWS trainborne

sub-system. It describes the operation of the sub-system from the TPWS aerial detecting the transmitter loops, the response of the control equipment and driver’s interface, through to the brake interface. Understanding the exact nature of these states and the entry and exit conditions may help during fault finding particularly when analysing the outputs of train data recorders.

2.4.2 Figure 8 shows the normal system response states of the TPWS trainborne sub-system.

OPERATIONAL READY STATE

ARMING TRANSMITTER LOOP DETECTED

NORMAL DIRECTION OSS PRIMED STATE

(OSS ND TIMER STARTED)

TPWS BRAKE DEMAND

NORMAL DIRECTION TSS PRIMED STATE

TRIGGER TRANSMITTER LOOP DETECTED

OPPOSITE DIRECTION OSS PRIMED STATE

(OSS OD TIMER STARTED)

f1 DETECTED f3 DETECTED f4 DETECTED f6 DETECTED

f2 DETECTED f2 DETECTED f5 DETECTED f5 DETECTED

HAS OSS ND TIMER EXPIRED?

HAS OSS OD TIMER EXPIRED?

IS f3 STILL PRESENT?

IS f6 STILL PRESENT?

OPPOSITE DIRECTION TSS PRIMED STATE

YES NO

YES NO

NO YES

NOYES

BRAKE DEMAND INDICATOR FLASHINGSTART BRAKE TIMER

BRAKE DEMAND INDICATOR STEADY

DRIVER PRESSES ACKNOWLEDGE PUSH-

BUTTON

BRAKE DEMAND INDICATOR OFF

TPWS BRAKE DEMAND RELEASED

YES

HAS BRAKE DEMAND TIMER

EXPIRED?

NO

Figure 8 TPWS trainborne sub-system state diagram




2.4.3 Power to the TPWS trainborne sub-system is normally controlled by the cab master switch such that the control unit only receives power when a master key has been inserted into the master controller and the neutral/engine only position has been selected. On dual-cab vehicles such as locomotives, the dual cab switching unit/change end switch must be operated to allow the TPWS aerial and driver’s display/control panel to be in circuit.

2.4.4 When power is applied to the TPWS trainborne sub-system, the control unit cycles through a self-test process to determine whether the sub-system is able to function correctly. The different trainborne manufacturers systems approach this in a slightly different way but the end result is to provide confidence that the system is fit to enter service.

2.4.5 When initialising a cab, including when changing ends on a dual cab vehicle, the self-test is initiated automatically. Once, the self-test routine has been successfully concluded then the sub-system moves to the operational ready state.

2.4.6 If the self-test fails then the TPWS system annunciates this to the driver by flashing the temporary isolation/fault indicator on the driver’s display/control panel and it will be necessary for the driver to operate the temporary isolation facility. Under these circumstances the sub-system will release the brake demand unless the AWS self-test has also failed.

2.4.7 Following successful self-testing, the equipment enters the operational ready state where it is set to detect the TPWS track-mounted transmitter loops and to respond accordingly. The TPWS visual indicators are all unlit.

2.4.8 It is important to understand that the normal direction functionality is independent of the opposite direction functionality such that normal direction and opposite direction transmitter loops may be detected and acted upon independently. This allows normal direction and opposite direction overspeed and/or trainstop transmitter loops to be applied to the same track for the same direction of travel if required.

2.4.9 A number of suppliers’ systems conduct aerial integrity tests when in the operating ready state by testing the aerial in a similar manner as during the power up test, but only when an AWS clear signal has been detected from the track-mounted magnets. It is only in this circumstance that the requirement for the TPWS system to function is unlikely to be required.

2.4.10 If the TPWS aerial detects an OSS arming transmitter loop frequency (f1 or f4), the trainborne sub-system enters the OSS primed state whereupon it starts the normal direction or opposite direction OSS timer as appropriate (the OSS timers are set to either 974 ms for passenger brake timed trains or 1218 ms for freight brake timed trains). Thus on detecting an f1 frequency the normal direction OSS timer will start, and the opposite direction OSS timer will start detecting an f4 frequency. These timers will operate in parallel should the track-mounted layout of transmitter loops require this.

2.4.11 If the OSS timer expires before the paired OSS trigger loop is detected, then the trainborne sub-system returns to the operational ready state. If the paired OSS trigger loop is detected before the OSS timer has expired then the control unit logic will command a brake demand but only if the OSS trigger loop detected is a frequency associated with a valid pair, for example f1 followed by f2 or f4 followed by f5. Any other combinations of OSS frequencies are rejected and the sub-system returns to the operational ready state.




2.4.12 If the TPWS aerial detects one of the TSS arming transmitter loop frequencies (f3 or f6), the system enters the normal direction or opposite direction TSS primed state. If the aerial then immediately detects the paired TSS trigger loop frequency, whilst still detecting the arming loop frequency, then it will command a brake demand. The control unit has separate and independent functionality for the normal direction TSS (f3 followed by f2 and f3 together) and opposite direction TSS (f6 followed by f5 and f6 together), such that the two can function in parallel on a bi-directionally signalled track. Any other combinations of TSS frequencies will not invoke a brake demand.

2.4.13 The requirement to detect the arming loop frequency first and then detect the trigger loop frequency provides the TSS with the ability to stop trains in one direction only. The requirement to detect both frequencies at the same time allows the TSS to operate with no lower speed limit.

2.4.14 Once a brake demand is commanded, the TPWS brake demand timer is started (nominally one minute) and the brake demand indicator flashes. The control unit awaits an input from the TPWS acknowledge pushbutton which sets the brake demand indicator to the steady state. Once the TPWS acknowledge pushbutton has been pressed and the brake demand timer has expired, the TPWS brake demand is released and the brake demand indicator extinguishes.

2.4.15 Three further states exist:

a) Full isolation - entered by operating the full isolation switch. Any existing TPWS brake demand is cancelled and power is removed from the control unit.

b) Temporary isolation - entered by operating the temporary isolation switch. This will not cancel an existing TPWS brake demand with the exception of the case where the train has stopped with the TPWS aerial directly above an active TSS and the >59 seconds has expired. The control unit remains active but does not respond to detected transmitter loops.

c) TSO – entered by pressing the TSO pushbutton. In this state a timer is started (preset either to 20 seconds generally for passenger trains or 60 seconds normally for freight trains) and the trainborne sub-system will return to the operational ready state once the timer expires or once an active train stop has been detected. The OSS facility remains active throughout.

2.5 Trainborne equipment – general description 2.5.1 General

2.5.1.1 This section provides an outline description of the components of the AWS and TPWS trainborne sub-system. Details of the various manufacturers’ equipment currently in use are included in sections 2.6, 2.7, 2.8 and 2.9.

2.5.1.2 As most manufacturers have included the functionality of AWS and TPWS in a combined control unit, both AWS and TPWS equipment are described together to enable an understanding of the most commonly installed configurations. However, it is important to note that either system (AWS or TPWS) can be applied on its own, and in some cases, for example certain Class 08 shunting locomotives, only TPWS has been implemented.

2.5.1.3 Specific part numbers and British Rail Catalogue numbers are detailed in section 2.11.3 together with details of equipment compatibility.




2.5.2 Trainborne sub-system components 2.5.2.1 Figure 9 depicts a typical trainborne sub-system including both AWS and TPWS

using a combined AWS and TPWS electronic control unit.

Figure 9 Typical AWS/TPWS trainborne sub-system

2.5.2.2 Note that the boxes shown dotted are only necessary for a dual-cab single control unit configuration such as on a locomotive.

2.5.3 Combined electronic control unit 2.5.3.1 The combined AWS and TPWS control unit (Figure 10) performs the logical

functions, receiving various inputs and driving the external control and indication equipment. Most control units in use are electronic replacing the earlier British Rail relay logic types.

2.5.3.2 The control unit may also provide specific outputs to reset the vigilance system (where a multi-re-settable vigilance device is used) and outputs to train data recorders to enable recording of the detection of track magnets together with the response of the trainborne sub-systems.




Figure 10 Typical TPWS control unit

2.5.4 AWS receiver 2.5.4.1 The AWS receiver (Figure 11) detects the presence of the south and north poles

from the track-mounted magnets and provides a signal to the control unit that one or both of the magnets have been detected. Several different types of receiver exist (although not all types may still be in use), including pivoted permanent magnet, standard and high strength bi-stable reed relay type, twin lightweight bi-stable reed relay, and electronic/solid state.

Figure 11 Typical AWS receiver

2.5.4.2 Some fleets may be fitted with two receivers, one to detect standard strength track magnets and one to detect extra strength track magnets (the twin-lightweight receiver and electronic versions are designed to detect either magnet types within a single housing). Where both receiver types are fitted, the vehicle control circuitry is arranged to select the correct receiver depending on the traction current collection system in use. Locomotives and other dual-cab vehicles are normally only fitted with one receiver unless they have two independent AWS trainborne sub-systems, one for each cab.

2.5.4.3 The receiver is mounted underneath the driving vehicle (Figure 12) (either on the bogie or suspended from the vehicle underside) nominally on the centre line of the vehicle, and within a height range that keeps the equipment both within kinematic gauge and able to respond to the minimum trackside magnet field strength specified in GE/RT8035 under all dynamic conditions. The receiver cable is connected to a junction box which forms a coupling and test point.




Figure 12 Typical AWS receiver mounted on bogie

2.5.4.4 The pivoted permanent magnet type receiver was the original type developed but was not reliable at speeds over 100 mph. This type of receiver is no longer in use, being replaced by more reliable receivers described below.

2.5.4.5 The bi-stable reed relay type of receiver is available as a standard strength unit (for vehicles not operating on dc electrified lines) and as an extra strength unit (for vehicles operating on dc electrified lines). The receiver incorporates a single bi-stable reed relay and two power relays, one north and one south. The assembly used for operating on dc electrified lines also includes shielding to reduce the magnetic field experienced by the receiver from strong magnetic fields produced by the third/fourth rail electrification systems.

2.5.4.6 The twin light-weight receiver (Figure 13) incorporates both a standard strength and a high strength bi-stable reed switch into one housing. This has the space advantages of being a single unit where traditionally a separate standard and extra strength receiver would be required.

Figure 13 Typical AWS twin-lightweight receiver

2.5.4.7 Due to the reliability and obsolescence factors, the bi-stable reed switch is gradually being replaced by electronic solid-state receivers. These operate on the ‘Hall Effect’ principle of sensing magnetic fields and incorporate a magnetic switch. As for the twin-lightweight, a single electronic receiver is able to detect both standard and high strength magnets, thus reducing space and weight requirements. There are also no moving parts in the electronic receiver which should increase reliability. A further advantage is that there may be no requirement to adjust the height of the receiver as the wheels wear or tyres are turned, depending on manufacturer and specific installations.




2.5.5 AWS alarm and indicator unit 2.5.5.1 The alarm and indicator unit (Figure 14) provides the main interface with the

driver. The unit contains the electronic tone generator for the ‘caution’ (approximately 800 Hz continuous tone) and ‘clear’ (approximately 1200 Hz chime) tones, and contains the yellow/black visual indicator (also known as the sunflower indicator) to remind the driver of the previous aspect/actions taken. The unit is mounted in a position where the driver may readily see it from the normal driving position. Several versions of this equipment exist, including those with a mechanical sunflower and those with LED arrays to provide the yellow element of the sunflower.

Figure 14 Typical AWS alarm and indicator unit

2.5.5.2 Older installations, on locomotives for example, have separate audible (bell and horn) and visual indicators (sunflower). Most have conventional electric trembler bells, which ring for 0.5 seconds for a clear signal, and pneumatic horns. The horn may be of the ‘Yodalarm’ electric type.

2.5.5.3 The visual ‘sunflower’ indicator (Figure 15) is normally of a mechanical operation type and is much larger than the combined alarm and indicator unit type. It contains a bi-stable electro-mechanical device with a magnetic circuit incorporating two coils, and is magnetically latched in either of its two positions. The first coil receives a 12V dc pulse every time the receiver detects a south pole, driving the indicator to ‘all black’. The second coil receives a 12V dc pulse when the driver presses the AWS acknowledge pushbutton after the caution indication horn has begun to sound, driving the indicator to the ‘black and yellow’ condition. In the latter state a proving contact is made, permitting a 40V dc pulse to pass to the receiver reset coil when the driver releases the AWS acknowledge pushbutton. Luminous paint is applied to the inner part of the yellow segments, so that the ‘black and yellow’ indication can be seen in the dark.

Figure 15 Typical AWS sunflower




2.5.6 TPWS aerial 2.5.6.1 The TPWS aerial (Figure 16) receives the 6 TPWS frequencies transmitted from

the track-mounted transmitter loops. The aerial, in conjunction with the control unit, may be capable of undertaking an integrity test as part of its in-built self-testing routines.

Figure 16 Typical TPWS aerial

2.5.6.2 The aerial is mounted underneath the leading vehicle (either on the bogie or suspended from the vehicle underside) nominally on the centre line of the vehicle, and within a height range that keeps the aerial both within kinematic gauge and able to respond to the minimum trackside transmitter loop field strength under all dynamic conditions.

2.5.6.3 For dual-cab vehicles, for example locomotives, two TPWS aerials are required, one at each end, to prevent detection of signal ‘self-reversion’. Self-reversion is an unwanted reaction to the signal returning to danger (red aspect) due to the natural passage of the train restoring the signal. If the TPWS aerial has not passed clear of the (now) active transmitter loops at the signal then the brakes would be applied by TPWS as an unwarranted application. Self-reversion can also occur on a single-cab vehicle if the aerial is mounted more than 2.3 m behind the leading wheelset.

2.5.7 Driver’s panel 2.5.7.1 The driver’s control panel (also known as the driver’s display unit or driver’s

display panel) consists of TPWS status indicators and a TSO pushbutton (Figure 17).

Figure 17 Typical TPWS driver’s control panel




2.5.7.2 A brake demand indicator indicates one of three TPWS brake demand states:

a) Unlit – no demand requested.

b) Flashing – brake demand requested by TPWS but not acknowledged by driver.

c) Steady - brake demand requested by TPWS and acknowledged by driver.

2.5.7.3 The driver’s control panel also contains a temporary isolation/fault indicator which also indicates three states:

a) Unlit – TPWS operational.

b) Flashing – TPWS fault detected.

c) Steady - TPWS temporarily isolated.

2.5.7.4 The TSO pushbutton is pressed by the driver when it is necessary to pass a signal at danger with the authority of the signaller. In this case, the TSS on the track would still be transmitting and hence the train would be tripped on a legitimate movement past the stop signal. However, the driver can operate the TSO which will prevent a brake demand from the first TSS the system encounters within a time period. After the time period (preset to 20 seconds for a passenger train or 60 seconds for a freight train), or on detecting the first TSS, the TSO will be reset to normal. When the TSO function is in operation, the TSO pushbutton illuminates steady yellow.

2.5.8 AWS reset pushbutton/TPWS acknowledgement 2.5.8.1 The AWS reset pushbutton (sometimes referred to as the AWS

acknowledgement pushbutton) is also part of the driver’s interface and is mounted on or built into the driver’s desk such that it can be readily operated from the driving position. The pushbutton (Figure 18) contains a changeover contact which allows the AWS receiver to reset, the audible indication to be silenced and the visual indication to be set to ‘yellow/black’.

2.5.8.2 The same pushbutton is also normally used to acknowledge a TPWS brake demand. When pressed after a TPWS brake demand, the control unit receives an acknowledge input which will enable the release of the TPWS brake demand in combination with a preset timer.

Figure 18 Typical reset/acknowledge button

2.5.9 Power supply unit (PSU) 2.5.9.1 UK traction and rolling stock operates with various battery/control supply

voltages, ranging from a nominal 24V dc to 110V dc. Various types of PSU are available (Figure 19). The PSU (also known as the voltage converter) isolates the vehicle battery/control supplies from the AWS and TPWS circuits and converts the vehicle battery/control supply to the AWS and TPWS operating voltages, nominally 12.5V dc for the control unit and the alarm and indicator unit




(or separate indicator/bell and horn) and 40V dc for the reset coil in the AWS receivers. Older style voltage converters are bolted into a base unit which makes the electrical connection through a jacking strip. The PSU will normally be protected by a device such as a miniature circuit breaker which will isolate the AWS system if operated either through a fault or manually.

Figure 19 Typical PSU

2.5.10 Brake demand relay 2.5.10.1 The AWS/TPWS control unit interfaces with the train’s brake system via a brake

relay/valve in order to implement an emergency brake application. Several types exist depending on the nature of the brake system installed. This is part of the train’s brake system.

2.5.11 Electro pneumatic valve 2.5.11.1 An electro pneumatic (EP) valve is used to control the AWS or TPWS brake

application on locomotives. Two types are used, ‘air’ or ‘vacuum’. The EP valve sits on a base unit through which the pneumatic and electrical connections are made.

2.5.12 Change end/isolation switch 2.5.12.1 The change end/isolation switch is used where there are two driving cabs on the

same vehicle utilising just one control unit, for example locomotives. The switch is operated by the driver to select which cab is in use. On more modern locomotives this may be achieved through the master controller acting on a dual-cab switching unit rather than a separate switch.

2.5.12.2 A change end/isolation switch is normally mounted at ceiling height inside each cab, and when operated in one cab (provided it is off in the other cab) connects or disconnects the AWS reset pushbutton, alarm and indicator unit and EP valve to/from the control unit to ensure the AWS is operative in the driving cab and inoperative in the non-driving cab. The existing change end/isolation switch may also be used to determine which TPWS aerial and controls should be in circuit, but normally a separate device is used.

2.5.12.3 The switches are colour coded and are not interchangeable.

2.5.12.4 The switch also incorporates a sealed open AWS/TPWS full isolation switch.

2.5.13 Full isolation switch and indicator 2.5.13.1 A full isolation switch (Figure 20) is provided for the driver to isolate the AWS and

TPWS trainborne sub-system in the case of faults where the brakes will not release, the AWS audible indications will not silence or a succession of incorrect or spurious responses are given by the AWS or TPWS systems. Various types exist, the older types being retained in the normal position with a seal or locking wire to deter abuse, or more modern installations arranged such that the switch cannot be reset by the driver. The change end/isolation switch on older locomotives may also include the full isolation switch as described above.




2.5.13.2 Full isolation of AWS will also render the TPWS system isolated (and vice versa) as the control unit also includes TPWS functionality. A TPWS temporary isolation switch is provided to overcome this limitation when only TPWS may be at fault.

2.5.13.3 Full isolation is required to be indicated to the driver by a discrete indication or as part of a general safety system isolation indication. This is achieved on older vehicles by the visible position of the isolation switch and on modern vehicles by an illuminated indicator. The full isolation switch is required to:

a) Ensure that the power supply is isolated from the AWS trainborne sub-system.

b) Ensure that no AWS or TPWS brake demand is or can be actioned.

c) Ensure that all indications except the isolation status indicator are inoperative.

d) Provide a clearly visible indication that enables a trainborne sub-system isolation to be detected in all relevant driving positions.

e) Provide an output to the train’s data recorder, where fitted, to indicate that the complete system is isolated.

Figure 20 Typical full isolation switch

2.5.14 TPWS temporary isolation switch 2.5.14.1 A TPWS temporary isolation switch (Figure 21) is provided to allow the TPWS

trainborne sub-system to be isolated either for operational reasons or to overcome a fault in the sub-system which does not affect the AWS functions, for example a faulty TPWS antenna.

2.5.14.2 The switch is centre-biased to the ‘off’ position so that when the equipment is powered down and on again, any existing temporary isolation will be removed.

2.5.14.3 The switch is mounted out of reach from the normal driving position.

2.5.14.4 On dual-cab vehicles only one temporary isolation switch is provided.




Figure 21 Typical TPWS temporary isolation switch

2.6 Trainborne equipment – manufacturers’ products (Howells) 2.6.1 Howells railway products

2.6.1.1 Rolling stock designed and built prior to 2001 would have been fitted with the traditional ‘British Rail’ AWS trainborne sub-system largely manufactured by Howells Railway Products Ltd (herein referred to as ‘Howells’). Howells do not manufacture a TPWS system or components, but Howells AWS components continue in use today.

2.6.2 Relay unit and relay junction box 2.6.2.1 The AWS logical functions are performed by relay logic (in the relay unit) to

provide the various states described in section 2.2. With the introduction of the TPWS, the AWS relay unit has predominantly been replaced by a modern electronic equivalent. The relay unit attaches to the vehicle by plugging into a base unit (the relay junction box) through which the electrical connections are made using jacking strips (see Figure 22).

Figure 22 Howells relay unit and relay junction box

2.6.3 AWS receiver and junction box 2.6.3.1 Howells manufacture reed relay AWS receivers are still in use on many fleets

fitted with AWS and TPWS. An underframe mounted receiver junction box is also available (Figure 23).




Figure 23 Howells AWS receiver and junction box

2.6.4 EP valve 2.6.4.1 Howells also manufacture an EP valve used to apply the train brakes when

demanded by the relay unit or modern electronic control unit (Figure 24).

Figure 24 Howells EP valve

2.6.5 EP repeat and horn relay unit 2.6.5.1 This equipment will have been removed when vehicles were fitted with TPWS.

2.6.6 Brake and horn relay unit 2.6.6.1 This equipment will have been removed when vehicles were fitted with TPWS.

2.6.7 Vacuum horn and air horn 2.6.7.1 This equipment will have been removed when vehicles were fitted with TPWS.

2.6.8 AWS bell 2.6.8.1 The electric trembler AWS bell manufactured by Howells (Figure 25) is connected

to the relay unit junction box by plug and socket or wired directly into a modern electronic AWS/TPWS control unit.

Figure 25 Howells electric trembler AWS bell




2.6.9 AWS indicator 2.6.9.1 Howells manufacture two variants of the traditional AWS ‘sunflower’ indicator

(Figure 26). One is a ‘bulkhead mounting’ version, the other a ‘flush mounting’ version for mounting in a panel or direct onto the driving desk. Both types plug into a base unit which terminates the vehicle wiring.

Figure 26 Howells bulkhead mounting and flush mounting AWS indicators

2.6.10 Voltage converters 2.6.10.1 Howells voltage converters were predominantly removed when vehicles were

fitted with TPWS.

2.6.11 AWS reset pushbutton 2.6.11.1 Howells manufacture the traditional desk-mounted dome AWS reset pushbutton

(Figure 27).

2.6.11.2 The pushbutton dome may be mounted directly on the driving desk or may be suspended below it such that only the chromed plunger is protruding above the driver’s desk panel.

Figure 27 Howells traditional desk-mounted dome AWS reset pushbutton

2.6.12 AWS isolation switch 2.6.12.1 The Howells AWS isolating switch (Figure 28) is used on older vehicles to

perform full isolation of AWS (and TPWS where fitted). On vehicles where AWS cannot be switched by the driver’s master key controller, this form of switch may be used to perform the ‘change end’ functions of a change end switch.




Figure 28 Howells AWS isolation switch

2.6.13 Change end switch 2.6.13.1 Howells’ manufacture two types of change end switch, one for use with air

systems and the other with vacuum systems.

2.7 Trainborne equipment – manufacturers’ products (STS Signals Ltd) 2.7.1 STS Signals Ltd

2.7.1.1 STS Signals Ltd (herein referred to as ‘STS’) have manufactured and supplied electronic TPWS control units for Class 373 and Class 92 locomotives as an add-on to their AWS equipment. Trainborne sub-system components and technical descriptions are given below. Electrical specification/connection details are given in Appendix D.

2.7.2 AWS receiver 2.7.2.1 STS manufacture a ‘twin-lightweight’ AWS receiver (Figure 29). This was

originally designed for use on Eurostar Class 373 and Class 92 locomotives, but has since been supplied on many new build sets and allows the trainborne AWS system to be used with a single AWS receiver over both ac and dc electrified lines.

2.7.2.2 The twin-lightweight AWS receiver is a robust integrated unit housing two sets of magnetic sensing elements. One element (Rx1) operates with ‘standard strength track magnets’ that are used on non-electrified and ac electrified lines. The second element (Rx2) operates with ‘extra strength magnets’ found on dc electrified lines. The unit is designed to survive at operating speeds of up to 300 kmh, but is designed to operate at up to at least 200 kmh. Selection of the two detector relays is determined from the Rx2 select line via the receiver selection relay unit in the PSU.

2.7.2.3 The twin-lightweight AWS receiver in-line entry unit incorporates an integral flexible conduit and connector. A side-entry version is also available for installations where it is not possible to fit the in-line version. Removable spacers are provided as part of the installation which are designed to be moved to below the receiver to accommodate wheel-wear as the unit becomes closer to the track-mounted magnets.




Figure 29 STS ‘twin-lightweight’ AWS receiver

2.7.3 Alarm and indicator unit 2.7.3.1 STS manufacture an AWS alarm and indicator unit.

2.8 Trainborne equipment – manufacturers’ products (Thales) 2.8.1 Thales

2.8.1.1 Thales UK Limited, Land and Joint Systems (herein referred to as ‘Thales’) manufacture a combined electronic AWS and TPWS control unit. Details of trainborne sub-system components and technical descriptions are given below and vehicle interface details are given in Appendix D. Note that some very early Thales TPWS equipment was manufactured under the Redifon MEL name.

2.8.2 Control unit 2.8.2.1 The Thales control unit (Figure 30) has been designed to easily replace the older

British Rail relay unit and junction box during retrospective fitment by using an interfacing terminal box. The terminal box is not necessary for new builds as its only function is to make use of the older ‘British Rail’ junction box footprint and wiring looms for ease of installation.

2.8.2.2 Whilst the control unit can be used for AWS functionality alone, it is invariably used for TPWS functionality as well and hence performs a dual role with separate inputs and outputs as required to drive the different system equipment. Elements of the control unit are used for both AWS and TPWS functionality, such as the input from the reset/acknowledgement pushbutton, the full isolation facility and the output to the brake application relay. If the control unit is used for AWS only, then a link is required to be made in the control unit connector to prevent a fault being indicated due to there being no TPWS antenna present. It should be noted that the Unipart Rail (formerly known as National Railway Supplies Limited) control unit uses the same electrical connector types as the Thales control unit but the two control units are not interchangeable.

2.8.2.3 The control unit logic is implemented in two Field Programmable Gate Arrays (FPGAs), one performing the AWS control function and the other performing the TPWS control functions. In addition to the main control functions, the FPGAs incorporate a comprehensive power up self-test function and a limited amount of continuous fault monitoring for AWS functions.

2.8.2.4 The control unit is powered by a 12.5V dc (+/-0.5V) supply obtained from the PSU.

2.8.2.5 The control unit contains two selectable AWS caution acknowledgement periods, the standard setting of 2.0 seconds and an alternative setting of 2.7 seconds for vehicles with a maximum operating speed of 100 mph or less. This is configured within the control unit terminal box or within the connector mating with control unit PL1 for installations not using a terminal box.




2.8.2.6 The control unit also contains a selectable timer to select the time for which the TSO function will remain active unless it is reset by an active TSS transmitter loop. The timer is configured in the terminal box or mating connector and has two settings:

a) 20 seconds – standard setting for passenger trains.

b) 60 seconds - extended setting for heavy freight trains.

2.8.2.7 The control unit also contains a pre-selectable timer to select the OSS timer. The timer is configured in the terminal box or mating connector and has two settings:

a) 974 ms – standard setting for passenger trains.

b) 1218 ms - extended setting for freight trains.

2.8.2.8 The control unit also provides a contact closure for 200 ms each time the AWS reset pushbutton is pressed as an input to a multi-resettable vigilance system. The vigilance equipment reset contact (RL9) is a voltage-free relay contact.

2.8.2.9 The control unit also provides 11 outputs to interface to the train data recorder. These contacts (RL1 to RL8 and RL10 to RL12) are voltage-free and close and then open during the power up sequence.

2.8.2.10 The indicator drives are solid-state outputs which switch to +12V in the active state. The two outputs to the AWS sunflower (set to ‘yellow/black’ and set to ‘all black’) are 250 ms pulses.

2.8.2.11 The brake interface provides a contact (RL13) which opens to demand a brake application. The relay is normally energised to hold the contact closed so that loss of power to the control unit will automatically cause a brake demand. In the case of full isolation of the control unit (which removes the control unit power) the full isolation switch provides an external short circuit across the brake control output. The relay has a mechanically linked monitor contact which is checked as part of the power up test.

2.8.2.12 When a train cab is powered up, the brake relay is held open whilst the control unit carries out a series of self-tests to check the integrity of the trainborne sub-system. Immediately after powering up the following sequence occurs:

a) The control panel indicators (mainly a TPWS function but the brake demand indicator is shared with AWS) illuminate.

b) The sunflower indicator changes to ‘yellow/black’ (if not already in this state) and then to ‘all black’.

c) Approximately 1.5 seconds later the audible AWS caution tone sounds to indicate that the initial AWS tests have been passed. The driver must respond to this by pressing and releasing the AWS reset pushbutton.

2.8.2.13 If the remainder of the AWS tests are successful the audible caution tone will be silenced, the control panel indicators will extinguish, the brake relay will close and the AWS clear audible tone may sound momentarily. It is the responsibility of the driver to check the correct control panel, sunflower indications and audible tones.

2.8.2.14 Operation of the AWS reset pushbutton, and the way in which it resets the AWS receivers to north pole condition, is identical to the relay-based AWS unit except that the control logic will not respond to the reset pushbutton if it is pressed before the AWS caution audible tone sounds. The AWS reset input acts as both an input for the reset pushbutton and a voltage source output for both the ac and dc AWS receiver reset coils which are connected in parallel.




Figure 30 Thales control unit

2.8.3 PSU 2.8.3.1 The AWS/TPWS PSU provides a 12.5V dc (+/-0.5V) supply to the control unit.

The PSU (Figure 31) also supplies 40V dc for the AWS receiver reset circuit. The PSU is situated near to the control unit which it supplies, and is supplied from the train’s dc control supply via the full isolation switch.

2.8.3.2 Thales supply two PSU variants, a nominal 24V dc (16 to 40V dc) input and a nominal 72/96V dc (50 to 121V dc) input.

2.8.3.3 Connection to the sealed PSU is via two military style circular bayonet connectors, one for the inputs (PL1) and one for the outputs (SK2). For retrospective fitment in place of older style converters, the PSU is mounted in a power supply assembly which includes ring terminal connections to enable a straight replacement for the older style converters.

2.8.3.4 The PSU is protected by an internal fuse which is not accessible to the user. The outputs are isolated from each other, the case and the input. The unit is protected from and will recover from short circuits. LEDs indicate the presence of the 12V dc output (U1) and 40V dc output (U2).

2.8.3.5 The PSU also incorporates a receiver selection relay which is used in conjunction with the twin lightweight AWS receiver to select either the ac lines (Rx1) or dc lines (Rx2) reed switch; the default reed switch is Rx1. The coil of this relay operates over the full input voltage range of supply.

2.8.3.6 It should be noted that Thales do not warrant that all other available AWS PSUs (voltage converters) will operate successfully with their electronic control unit due to EMC compatibility issues. Other approved voltage converters are detailed in section 2.11.

Figure 31 Thales AWS/TPWS PSU




2.8.4 Control unit terminal box 2.8.4.1 Two variants of the terminal box are available from Thales for retrospective

fitment, the Mark II on which the control unit is externally mounted and connected via external plugs, and the Mark III in which the control unit is internally mounted with terminals for all connections (Figure 32). The Mark III is designed for locations where public access may be possible and where two cab equipments are interfaced to one control unit. The control unit is mounted within the terminal box. The Mark I terminal box is obsolete and should be replaced for a Mark II or Mark III unit if found in service.

2.8.4.2 The Mark II control unit terminal box also contains the link necessary to set the AWS acknowledge period, or within the connector mating with control unit PL1 for installations not using a terminal box.

2.8.4.3 The Mark III control unit terminal box contains the links necessary to set the TPWS TSO timer period to 20 seconds or 60 seconds. For Mark II terminal boxes and installations not using a terminal box, this is configured within the connector mating with control unit SK2.

2.8.4.4 Similarly, the Mark III control unit terminal box contains the links necessary to set the TPWS OSS timer period to 974 ms or 1218 ms. For Mark II terminal boxes and installations not using a terminal box, this is configured within the connector mating with control unit SK2.

Figure 32 Thales Mark II and Mark III control unit terminal boxes

2.8.5 AWS alarm and indicator unit 2.8.5.1 Thales have developed an electronic AWS alarm and indicator unit which

provides the audible and visual indications required (Figure 33). The unit uses an LED array for the ‘yellow’ elements on the ‘sunflower’ in place of the traditional electro-mechanical versions.

2.8.5.2 The unit incorporates an electronic brightness adjustment to cater for the range of ambient lighting conditions present in driving cabs. The audible tones have 3 volume levels to cater for different ambient noise levels, which are preset at installation.

2.8.5.3 The unit is a direct replacement for other alarm and indicator units having identical connections and mounting arrangements.




Figure 33 Thales AWS alarm and indicator unit

2.8.6 Driver’s panel 2.8.6.1 The Thales TPWS driver’s control panel is provided with two flush-mounted,

tamper-resistant LED indicators and an illuminated pushbutton, with a horizontal or vertical orientation available (Figure 34).

2.8.6.2 The functions of the control panel indicators and pushbutton are as follows:

Temporary isolation/fault indicator

Off No fault detected during power up test, and temporary isolation not selected

Flashing yellow4 PUT has detected a fault with the OSS/TSS facility

Steady yellow4 The TSS/OSS trainborne functions are isolated

Brake demand indicator

Off No TPWS brake demand exists

Flashing red5 TPWS (or AWS) brake demand exists but has not been acknowledge

Steady red5 Brake demand exists and has been acknowledged

TSO switch/indicator

Off TSO is not active

On TSO is active

Table 1 Functions of the control panel indicators and pushbutton

2.8.6.3 Pressing the TSO switch will activate the TSO function.

2.8.6.4 During the power up test, all three indicators will illuminate for the driver to check correct operation of the control panel before reverting to the normal state described above.

4 On certain fleets, for example Class 357 this indicator is red 5 On certain fleets, for example Class 357 this indicator is yellow




Figure 34 Thales TPWS driver’s control panel

2.8.7 AWS/TPWS reset/acknowledge pushbutton 2.8.7.1 Thales supply a combined AWS/TPWS reset/acknowledge pushbutton (Figure

35).

2.8.7.2 The pushbutton is a momentary action switch with two forced action contact blocks. Each block comprises one normally open and one normally closed contact set. One contact block is used for the AWS reset and TPWS acknowledge function and is wired as a single pole changeover contact set. The other contact set is available for monitoring purposes such as a connection to the train data recorder.

Figure 35 Thales combined AWS/TPWS reset/acknowledgement pushbutton

2.8.8 AWS receiver 2.8.8.1 Thales manufacture an electronic solid-state AWS receiver which operates on the

‘Hall Effect’ principle (Figure 36). The receiver houses a latching magnetic switch which responds to the AWS track magnets.

2.8.8.2 The Thales Electronic AWS receiver (E-AWS receiver) can be used as a direct replacement for either a standard AWS receiver or the ‘twin-lightweight’ AWS receiver.

2.8.8.3 The E-AWS receiver is mounted on one of two alternative adaptor plates: type A for replacing a standard single electro-mechanical receiver and type B for new build vehicles or for replacing a twin-lightweight receiver. A mounting plate is also available for a TPWS aerial if this is currently mounted on the standard AWS receiver flux plate.

2.8.8.4 A range of installation kits is available both to suit existing AWS installations and to suit combined AWS and TPWS installations. The connecting cable is available in varying lengths, and is protected by a robust flexible conduit. A junction box is normally mounted on the vehicle underframe to separate the vehicle wiring from the flexible aerial connections.




2.8.8.5 As a replacement for a standard single AWS receiver, the conduit is terminated in the standard straight 5-pin AWS connector. For new build vehicles, or where replacing a twin-lightweight receiver, the unit is terminated in a 19-way Litton type bayonet connector.

2.8.8.6 An alternate power supply input is available, which, if selected, will de-sensitise the receiver specifically for dc operation (Rx2 mode) with extra strength track magnets. The purpose is to reduce the risk of false operation due to spurious magnetic fields from track-mounted traction supply cables and the like. If the Rx2 mode is not selected then the receiver will default to Rx1 mode for standard strength track magnets. However, this type of receiver has been fitted in unswitched (single sensitivity Rx1) mode on trains operating over both standard and extra strength magnets, and although this is non-compliant with issue one of GE/RT8035, a non-compliance has been authorised and issued against the standard (03/163/NC).

2.8.8.7 Depending on the installation design criteria (see Thales document TPWS/TIP/018), it is generally not necessary to adjust the E-AWS receiver for height following wheel-wear or tyre turning. Experience with this receiver has shown that it can operate reliably at static heights up to 210 mm ARL and can accommodate 30-40 mm of wheel-wear without the need for height compensation. However, Thales recommend that the maximum static height should not normally exceed 185 mm ARL to accommodate variations in track magnet outputs and the effects on the flux field from bogie characteristics (the exception to this might be where a vehicle has the E-AWS receiver set to standard strength position but works also over dc electrification areas where the height may be raised to reduce the risk of spurious operations by track cables carrying high traction currents). The lowest height limit is governed by track gauging requirements (100 mm ARL).

2.8.8.8 The electronic receiver also has an analogue output which is capable of being connected to a data logger to measure the magnet field strength of track magnets as the unit passes over them.

Figure 36 Thales electronic solid-state AWS receiver

2.8.9 TPWS aerial 2.8.9.1 The Thales composite TPWS aerial and harness (Figure 37) comprises a small

printed electronic circuit embedded in a strong nylon tube with an integral cable harness for the electrical connections to the vehicle. Note that on early installations of Thales TPWS equipment, the TPWS aerial is separate from the flexible cable and connected using an Amphenol connector. This arrangement has suffered from reliability problems.

2.8.9.2 The aerial PEC contains a tuned coil which responds to the electromagnetic field emitted from the transmitter loops. The PEC also contains a test coil which is driven from the control unit during the power up test sequence in order to prove the integrity of the aerial.




2.8.9.3 The aerial is mounted on a metal mounting bracket which provides protection against flying ballast to the upper part of the aerial. The lower part is protected by a reinforced nylon aerial deflector in the shape of a dome (Figure 38).

2.8.9.4 The aerial is connected via a strong flexible conduit containing twin-twisted pair signal wires within an overall screened cable which plugs into the aerial terminal box (or train ducting) mounted on the underside of the vehicle body. Fixed twin-twisted pair overall screened wiring connects the terminal box to the control unit.

2.8.9.5 The TPWS aerial harness assembly is terminated in either an Amphenol or Litton bayonet-lock type connector or may be terminated in crimped ring terminals. The harness is available in various lengths with straight or right-angle connectors.

Figure 37 Thales composite TPWS aerial and harness

Figure 38 Thales TPWS aerial bracket and deflector

2.8.10 Combined electronic AWS receiver and TPWS antenna 2.8.10.1 Thales also supply a combined TPWS aerial with electronic AWS receiver

mounted in a single housing (Figure 39). The combined unit has a single connecting cable thus reducing the space and equipment requirements. The combined unit also has a range of installation kits with varying cable lengths to suit specific applications.

2.8.10.2 The combined AWS receiver element of the combined unit is identical to the standard electronic receiver and can be used as a replacement for all existing receiver types described in this document.




Figure 39 Thales combined TPWS aerial with electronic AWS receiver

2.8.11 AWS/TPWS underframe junction box 2.8.11.1 Thales supply a range of underframe mounted junction boxes to connect to their

range of AWS receivers and TPWS aerials (Figure 40).

Figure 40 Thales underframe mounted junction boxes

2.8.12 Dual-cab switching unit 2.8.12.1 The dual-cab switching unit switches the various AWS and TPWS components

from one cab to the other. The Thales dual cab switching unit comprises a printed electronic circuit mounted vertically on the side of the control unit terminal box (this installation requires the Mark III terminal box to be used although another suitable enclosure could be used if no terminal box is otherwise required). Connections are made using Faston crimped spade terminations to edge connectors T1 to T37 and to additional connectors on T38 to T47.

2.8.12.2 Slave relays are provided on the unit to enable two such indicators to be driven in parallel on vehicles with separate sunflower units. A facility to switch inputs from 2 AWS reset pushbuttons is also provided.

2.8.12.3 The control input from the vehicle change end switch can be of either polarity and different unit configurations are provided.

2.8.13 Full isolation switch 2.8.13.1 Thales do not supply a specific AWS isolation switch. This is normally a standard

switch as supplied by the vehicle manufacturer or already existing on the vehicle where a retrospective application of their electronic control unit has been made.

2.8.14 TPWS temporary isolation switch 2.8.14.1 Thales supply a temporary isolation switch to allow the driver to temporarily

isolate TPWS in compliance with rules (Figure 41). The temporary isolation switch is a three position switch mounted on a stand-alone panel in the driving cab out of reach of the driver when seated at the driving position. Turning the switch clockwise selects temporary isolation and anti-clockwise deselects temporary isolation. The switch is centre biased so when it is released it returns to the centre position. The switch can also be supplied with a wired seal to prevent misuse or a hinged cover to prevent accidental operation.




2.8.14.2 It should be noted that on some vehicles, for example Class 313, temporary isolation switches have had an extra switch block added to input to the train data recorder when the switch has been operated.

Figure 41 Thales temporary isolation switch

2.9 Trainborne equipment – manufacturers’ products (Unipart Rail) 2.9.1 Unipart Rail products

2.9.1.1 Unipart Rail manufacture an electronic combined AWS and TPWS control unit. Unipart Rail also produce a ruggedised version of their equipment for use in harsh environments such as to be found on steam locomotives.

2.9.1.2 Details of trainborne sub-system components and technical descriptions are given below and vehicle interface details are given in Appendix F.

2.9.2 AWS/TPWS Specific Transmission Module 2.9.2.1 In addition to their standard control unit described below, Unipart Rail are jointly

developing an AWS/TPWS Specific Transmission Module (STM) with Siemens Transportation Systems. This unit, when available, will provide both full standalone AWS/TPWS functionality, and will act as an AWS/TPWS STM for the European Train Control System (ETCS) trainborne equipment.

2.9.3 Control unit 2.9.3.1 The Unipart Rail combined AWS and TPWS control unit (Figure 42) has been

designed to easily replace the standard ‘British Rail’ AWS relay units during retrospective fitment by using an interfacing junction box.

2.9.3.2 Whilst this control unit can be used for AWS functionality alone, it is invariably used for TPWS functionality as well and hence performs a dual role with separate inputs and outputs as required to drive the different system equipment. Note that the control unit has been applied to some shunting locomotives in TPWS only mode. If the control unit is used for AWS only, then a link is required to be made between the TPWS aerial test and aerial input terminals.

2.9.3.3 The Unipart Rail control unit is based on FPGA logic processing and a combined FPGA circuit is provided for AWS and TPWS functionality. Elements of the control unit are used for both AWS and TPWS functionality, such as the input from the AWS reset/TPWS acknowledgement pushbutton, the full isolation facility and the output to the brake application relay.

2.9.3.4 The control unit outputs are interfaced via volt-free relay contacts to preserve galvanic isolation. Volt-free contact outputs are provided for a train data recorder and vigilance system reset. The control supply for these outputs is sourced from the vehicle control circuits and is protected by a fuse/circuit breaker.

2.9.3.5 All timings necessary within the AWS and TPWS brake demand functions are performed by the control unit so there is no requirement for the external time delay features of the old ‘British Rail’ systems. The brake control output electrical ratings are detailed in Appendix F.




2.9.3.6 The control unit contains two selectable AWS caution acknowledgement periods, the standard setting of 2.0 seconds, and an alternative setting of 2.7 seconds for vehicles with a maximum operating speed of 100 mph or less. This is configured within the control unit junction box wiring.

2.9.3.7 The control unit performs a test of the TPWS aerial integrity whenever an AWS clear signal is detected. If the test is successful then no feedback is given to the driver, but if it is not successful then the temporary isolation/fault indicator on the driver’s control panel will flash continuously until a successful test is completed (this may occur at the next clear signal or the next TPWS power up sequence).

2.9.3.8 The control unit is fitted with two 37-way MIL-C-5015 electrical connectors, one male fixed plug and the other a female fixed socket. The electrical interface details for the fixed socket and fixed plug are detailed in Appendix F. It should be noted that the Unipart Rail control unit uses the same electrical connector types as the Thales control unit but the two control units are not interchangeable.

Figure 42 Unipart Rail combined AWS and TPWS control unit

2.9.4 Control unit junction box 2.9.4.1 Several types of control unit junction box are available from Unipart Rail

depending on whether the installation is protected in the vehicle or exposed to the public or atmosphere. The junction box interfaces the control unit to the vehicle wiring.

2.9.4.2 Junction box types 1 and 2 are designed to replace the older style AWS relay unit junction boxes and permit the existing vehicle wiring to be terminated in the same relative position. The control unit sits on top of these junction box types and the installation is aimed at typical multiple unit installations where the equipment is located in the cab roof or other similarly protected location. Type 1 includes additional terminals to connect the peripheral equipment to whereas with type 2 the peripheral equipment is connected directly into the control unit.

2.9.4.3 Junction box types 3 and 4 are designed to completely enclose the control unit for mounting in less well protected areas (type 3) or where the equipment would be exposed to a harsh atmosphere (type 4) for example on a steam locomotive. The junction box space envelope is similar to that of an older style AWS relay unit. Type 3 is capable of being fitted with a dual cab switching unit.

2.9.4.4 Electrical interface details for these junction boxes are detailed in Appendix F.

2.9.5 PSU 2.9.5.1 Unipart Rail manufacture a range of PSUs for this application to suit the range of

vehicle battery/control voltages (Figure 43). The Unipart Rail control unit and peripherals are also compatible with white square modified British Rail Specification 36 voltage converters.




Figure 43 Unipart Rail PSU

2.9.6 AWS receiver 2.9.6.1 Unipart Rail manufacture an electronic solid state AWS receiver as a direct

replacement for existing reed receivers (Figure 44). The electronic receiver is available with a range of cable lengths and connector types.

Figure 44 Unipart Rail electronic solid-state AWS receiver

2.9.7 AWS reset/TPWS acknowledge pushbutton 2.9.7.1 Unipart Rail manufacture a combined AWS reset and TPWS acknowledge

pushbutton for desk mounting.

2.9.8 TPWS aerial, junction box and cable assemblies 2.9.8.1 The Unipart Rail TPWS aerial is a solid state TPWS receiver and is normally

mounted on the bogie (Figure 45).

2.9.8.2 The TPWS aerial is self-tested regularly to assure system integrity. The test takes place every time the control unit detects an AWS clear indication (implying the corresponding signal is at green when TPWS will not be required for use for SPAD mitigation). If the aerial test is successful then there is no feedback to the driver, but if it fails then the temporary isolation/fault indicator will flash until a successful integrity test has been achieved either at the next AWS clear or at the next power up sequence test.

2.9.8.3 The TPWS aerial junction box is the interface between the vehicle wiring and the flexible TPWS aerial cable to the bogie mounted TPWS aerial. The junction box contains a 6-way MIL-C-5015 bayonet-lock electrical connector on one face that is wired to 4 M4 terminals located inside the junction box. Electrical connection details are provided in Appendix D.




Figure 45 Unipart Rail TPWS aerial

2.9.8.4 The TPWS aerial cable is a flexible cable assembly that connects the underframe mounted junction box to the bogie mounted aerial (Figure 46). The cable consists of a length of flexible conduit fitted with a 6-way MIL-C-5015 electrical connector on both ends. There are 3 variants available in different lengths:

a) Straight connector type - a straight connector is fitted on both ends.

b) Angled connector type – a 90° connector is fitted to both ends.

c) Mixed connector type – a straight connector is fitted on one end and a 90° angled connector on the other.

Figure 46 Unipart Rail TPWS aerial cable and junction box

2.9.9 Driver’s panel 2.9.9.1 The Unipart Rail driver’s control panel (Figure 47) is one of the system interfaces

with the driver. The panel has 3 visual indicators and a pushbutton, which is integral with one of the visual indicators on some variants of this equipment. All of the driver’s control panels use the same LED indicators. The functions of the indicators and pushbutton are as follows:

a) A red LED indicator (labelled brake demand) to advise the driver that the TPWS system (or AWS system) has demanded a brake application (flashing) and that the brake demand has been acknowledged by the driver (steady).

b) A yellow LED indicator (labelled temporary isolation/fault) with 3 distinct functions:




i) When the system is first powered up, this indicator will flash to advise the driver of the TPWS aerial integrity test that is performed during system power up (see below).

ii) When the system is in the normal operating mode this indicator will illuminate steadily to advise the driver that the TPWS functionality has been isolated by the use of the TPWS temporary isolation switch.

iii) This indicator will flash to advise the driver of the failure of the TPWS aerial integrity test that is detected when the system detects an AWS clear signal.

c) A yellow LED indicator (labelled TSO) that may be combined with the pushbutton, that is used by the driver to instigate the TSS override function to pass signal at danger with authority.

Figure 47 Unipart Rail driver’s control panel

2.9.9.2 A ‘harsh environment’ driver’s control panel (Figure 48) is available which has been designed for installations where the operating environment requires additional mechanical integrity, for example on steam locomotives. This version has a separate TSO pushbutton and indicator.

Figure 48 Unipart Rail ‘harsh environment’ driver’s control panel

2.9.9.3 Where AWS is not employed and the equipment is used for TPWS only, a specific driver’s control panel is used. The unit includes a TPWS acknowledge pushbutton in place of the normal AWS reset pushbutton used to acknowledge a TPWS brake demand. The unit also has a separate yellow power up LED indicator which illuminates instead of the AWS horn sounding on power up testing. In this case, the TPWS acknowledge pushbutton is used to complete the power up testing instead of the AWS reset pushbutton.

2.9.9.4 The driver’s control panel is available with a range of horizontal and vertical orientations with 6-way bayonet-lock MIL-C-5015 electrical connector or with M4 terminals. The electrical interface details for the driver’s control panel are detailed in Appendix F.




2.9.10 Dual cab switching unit 2.9.10.1 Installation on single vehicles with two driving cabs requires a dual cab switching

unit to control the AWS and TPWS components in each cab. The dual cab switching unit can be arranged to select the appropriate TPWS OSS timer setting for either passenger brake performance or goods brake performance, and switch the correct TPWS aerial and driver man machine interface.

2.9.10.2 Electrical interface connections for the dual cab switching unit are detailed in Appendix F.

2.9.10.3 Electrical connections are made using M4 terminals and the electrical interface connections for the dual cab switching unit are detailed in Appendix F.

2.9.11 TPWS aerial switching unit 2.9.11.1 The TPWS aerial switching unit is generally used where there is only one driving

position on a vehicle but 2 TPWS aerials are required to avoid self-reversion because the vehicle may be controlled for movements in both directions for example steam locomotives and Class 20 locomotives. Selection of the correct aerial is made using the vehicle direction controller. Electrical interface connections for the dual cab switching unit are detailed in Appendix F.

Figure 49 Unipart Rail TPWS aerial switching unit

2.9.12 Full isolation switch 2.9.12.1 Unipart Rail manufacture a specific AWS full isolation switch.

2.9.12.2 In addition, Unipart Rail manufacture an isolation unit combining the functions of the TPWS temporary isolation switch and the AWS/TPWS full isolation facility. This has been designed particularly for use on shunting locomotives (Class 08/09).

2.9.12.3 When the full isolation switch is in the ‘normal’ position, a power supply is switched to the TPWS PSU. When the full isolation switch is in the ‘isolate’ position, the full isolation indicator is illuminated and a false feed is provided to the brake relay and the PSU feed is isolated. The electrical specification of the isolation unit is contained in Appendix F.

Figure 50 Unipart Rail full isolation switch




2.9.13 TPWS isolation switches 2.9.13.1 Various forms of temporary isolation switch (Figure 51) are available from Unipart

Rail including standard Faston or screw type terminal variants, and enclosed version and a version for harsh environments such as with steam locomotives. The electrical specification of the temporary isolation switch is contained in Appendix F.

Figure 51 Unipart Rail TPWS temporary isolation switch

2.10 Data recording requirements 2.10.1 General requirements

2.10.1.1 GM/RT2472 requires the following AWS and TPWS related functions to be recorded:

a) Train brake demand by AWS or TPWS.

b) Operation of AWS and the driver’s response.

c) Isolation of AWS.

d) Operation of TPWS and the driver’s response.

e) Isolation and override of TPWS.

2.10.1.2 The precise application is vehicle specific but is likely to include the following:

a) Energisation of the AWS ‘B’ coil (the coil that sets the AWS indicator to ‘all black’ for example when the AWS receiver passes over the south magnet).

b) Operation by the driver of the AWS reset pushbutton.

c) Sounding of the audible AWS caution indication (horn or electronic tone).

d) Sounding of the audible AWS clear indication (bell or electronic chime).

e) Brake demand requested by AWS or TPWS.

f) Isolation of the AWS/TPWS control unit.

g) Operation by the driver of the TPWS acknowledge pushbutton.

h) Normal direction transmitter loop detected.

i) Opposite direction transmitter loop detected.

j) TSO pushbutton operated.

k) Fault and/or temporary isolation of the TPWS control unit.

l) Full isolation of the TPWS control unit.




2.10.1.3 AWS and TPWS data will be used for driver performance monitoring, post incident investigation and may aid fault finding.

2.10.1.4 Reference should be made to the vehicle wiring diagrams to determine which inputs are configured on each vehicle type.

2.10.1.5 These functions may be output to the train data recorder either from the volt-free contacts within the control unit, or, on some vehicles for example Class 315, directly from some AWS functions.

2.10.3 STS 2.10.3.1 For details of the STS control unit train data recorder outputs contact the

manufacturer.

2.10.4 Thales 2.10.4.1 The Thales control unit provides 11 outputs to a train data recorder in the form of

voltage-free contacts, as shown in Table 2 below:

Train data recorder output Condition for closed contact

Brake demand requested Brake relay de-energised

AWS clear signal annunciated Bell control output true

AWS restrictive signal annunciated Horn control output true

AWS sunflower set to ‘all black’ Set to all black output pulse present

AWS sunflower set to ‘yellow/black’ Set to yellow/black output pulse present

AWS reset pushbutton pressed AWS reset pushbutton pressed

AWS isolated/TPWS fully isolated Control unit powered down

TPWS temporary isolation/fault TPWS temporary isolation/fault indicator lit (pulses while indicator is flashing)

TPWS normal direction loop detected F1, F2 or F3 loop detected

TPWS opposite direction loop detected F4, F5 or F6 loop detected

TPWS TSO operated TSO indicator lit

Table 2 Thales control unit train data recorder outputs

2.10.2 Unipart Rail Limited 2.10.2.1 The Unipart Rail control unit provides 12 outputs to a train data recorder in the

form of voltage-free contacts, as detailed in Table 3 below:

AWS train data recorder outputs TPWS train data recorder outputs Clear signal annunciated Normal direction loop detected Restrictive signal annunciated Opposite direction loop detected Sunflower set to ‘all black’ TSO activated Sunflower set to ‘yellow/black’ Temporarily isolated Reset pushbutton pressed Temporary isolation/fault indicator lit Brake demand requested Brake demand requested

Table 3 Unipart Rail control unit train outputs




2.11 Configuration management and equipment compatibility 2.11.1 General

2.11.1.1 Configuration management of AWS and TPWS equipment is a vital process as the AWS and TPWS systems provide vital safety functions. Railway undertakings (train operators), suppliers and manufacturers are required to operate a reliable system of configuration management to ensure that equipment in use accords with, for example, the latest modification status and that incompatible equipment is not connected together.

2.11.1.2 AWS and TPWS Railway Group Standards (GE/RT8035 and GE/RT8030 respectively) require that where vehicles are being modified in the area covered by the scope of the standard, the design must be reviewed and, where reasonably practicable, brought into line with the requirements of the standard. Where it is not reasonably practicable to do so, the situation must be regularised by means of a deviation in accordance with the Railway Group Standards Code. However, there is no mandatory requirement to bring existing vehicles into compliance with the AWS standard (GE/RT8035) when AWS equipment is replaced on a like-for-like basis.

2.11.2 New and modified components 2.11.2.1 From time to time new AWS and TPWS products will come to the market as

replacements for existing equipment, either to replace obsolete items, improve reliability or reduce costs. It is incumbent on the manufacturer/supplier to follow industry processes to gain approval of the product for use in service. Railway undertakings (train operators) should only use approved items of equipment.

2.11.2.2 Where existing AWS or TPWS equipment requires modification, then the manufacturer/supplier is required to follow recognised industry processes for approval of the modification where it impacts on form, fit or function. Again, railway undertakings (train operators) should only use approved items of equipment.

2.11.2.3 New and modified AWS and TPWS components should be assessed for compliance to GE/RT8035 and GE/RT8030 respectively.

2.11.3 Compatibility 2.11.3.1 AWS and TPWS components are supplied by a number of different

manufacturers as identified in this document, there are no mandatory technical specifications for the interfaces between individual components creating a manufacturers’ trainborne sub-system. Therefore, there are no guarantees that one component supplied by manufacturer A is compatible (under all foreseeable conditions) with a similar component from manufacturer B, unless this is declared by the manufacturers. Where it is proposed to use a component from one supplier to replace another’s which has not previously been interfaced to that equipment, then guidance should be sought from the manufacturers involved.

2.11.3.2 However, certain components in the trainborne sub-system have been developed over many years to be compatible with each other, and certain declarations have been made by manufacturers. The following tables (arranged by manufacturer) identify the equipment build status and the known compatibility declarations for the main AWS and TPWS equipment manufacturers as at the time of publication of this document:

a) Table 4 – Howells Railway Products Ltd

b) Table 5- - STS Signals Ltd

c) Table 6 – Thales UK Limited, Land and Joint Systems




d) Table 7 – Unipart Rail

2.11.3.3 Entries in these matrices ‘not known’ will be populated with data when provided by the equipment manufacturers at a subsequent re-issue of this document.

2.11.3.4 Readers should refer to their company documentation, or to the equipment manufacturer, to check for any updates to equipment build status and compatibility.




Howells item Description/

Howells part no. Catalogue no.

Compatibility Comments

Not known 062/500006 n/a No longer in main line use – superseded by TPWS

AWS relay unit


Relay unit junction box

Not known 062/500016 Howells and Unipart Rail relay units

No longer in main line use – superseded by TPWS

Voltage converter 24V dc

Howells’ AWS relay unit Coloured green – with white square modification only

Voltage converter 70/90V dc

062/014631 Howells’ AWS relay unit and all Thales electronic control units

Coloured yellow – with white square modification only.

PSU

Voltage converter 110V dc

Howells’ AWS relay unit Coloured grey – with white square modification only

With carrier – standard (orange)

Unipart Rail and Thales electronic control units

Reed relay type for use on vehicles not operating in dc electrified areas

Without carrier– standard (orange)


Reed relay type for use on vehicles not operating in dc electrified areas

AWS receiver

High speed (yellow)


Reed relay type extra strength for dc electrified lines

AWS receiver junction box – 5 pin type

Not known 062/500017 All AWS receivers fitted with a 5 pin plug

AWS alarm and indicator unit

Not known 098/006925 Thales electronic control units

Bulkhead mounting

062/500028 Some Thales electronic control units

Not compatible with Thales control unit 606108-00

AWS indicator (sunflower)

Flush mounting 062/500029 Some Thales electronic control units

Not compatible with Thales control unit 606108-00

Yodalarm type 062/017967 Unipart Rail and Thales electronic control units

Yodalarm type 062/015985 Unipart Rail and Thales electronic control units

May also be used on steam locomotives with Unipart Rail equipment

Air horn 062/500027 n/a Removed when TPWS fitted

AWS horn

Vacuum horn 062/500044 n/a Removed when TPWS fitted




Howells item Description/ Howells part no.

Catalogue no.


AWS bell Not known 062/500015 All electronic control units

Not known 062/500035 Not known


AWS brake demand EP valve


Not known 062/500036 n/a Removed when TPWS fitted

EP repeat relay


Brake and horn relay unit


AWS reset pushbutton

Not known 062/500031 Unipart Rail and Thales electronic control units

May also be used on steam locomotives using Unipart Rail equipment

AWS isolation switch



Cab change end switch


Table 4 Howells Railway Products Limited




STS item Description/ STS part no.

Catalogue no.


AWS/TPWS control unit

STS PSUs only STS, Unipart Rail and Thales AWS receivers listed in this document STS, Unipart Rail and Thales alarm and indicator units listed in this document All AWS/TPWS reset/ acknowledge push buttons listed in this document

72V/96V dc nominal

STS control unit6 PSU

110V dc nominal STS control unit6

062/014454 STS, Unipart Rail and Thales electronic control units

LED variant



Former Field and Grant design



062/010900 STS , Unipart Rail and Thales electronic control units

AWS Twin-lightweight receiver


AWS twin lightweight receiver junction box

STS twin lightweight AWS receiver only

TPWS drivers control panel

STS electronic control units only

TPWS temporary isolation switch

STS, Unipart Rail and Thales electronic control units

TPWS aerial assembly

STS electronic control units only

TPWS aerial junction box

STS TPWS aerials only

TPWS aerial mounting plate and cover

STS TPWS aerials only

TPWS aerial switching unit

- - STS electronic control units only

Table 5 STS 6 Will function with other manufacturers AWS and TPWS equipment but not warranted as compatibility has not been tested.




Thales item Description/ Thales part no.

Catalogue no.


606108-00 Not for new supply - any found in service should be replaced with the latest modification state and returned to Thales

First production unit. compatible only with AWS alarm and indicator unit (cannot drive separate sunflower indicator)

606108-00 modification 1 CN36970

Not for new supply - any found in service should be replaced with the latest modification state and returned to Thales

As 606108-00 but fitted with modified logic chip to prevent spurious ‘lobe’ trips

606108-01 098/017819 Not for new supply - any found in service should be replaced with the latest modification state and returned to Thales

Increased drive capability for separate sunflower indicator


098/017819 Not for new supply - any found in service should be replaced with the latest modification state and returned to Thales

As 606108-01 but fitted with modified logic chip to prevent spurious ‘lobe’ trips

606108-01 modification 2

098/017819 Not for new supply – it is recommended that this modification level is returned to Thales for upgrade to latest modification status, especially if the serial number is listed in TIP003

To identify control units tested to TP604415 issue 9 using test software version 4.0


098/017819 Not for new supply – a user of this product may return it for free upgrade to modification level 4 if they are experiencing AWS reset failures

To identify control units with new build process relay. Will also have blue serial number label and white stripe


098/017819 Not for new supply – this is the current (at issue of this Guidance Note) highest build standard for this variant and is valid for use on vehicle designs specified for the ‘-01’ variant

To identify control units with new AWS reset relay

606108-02 098/016430 Not for new supply - any found in service should be replaced with the latest modification state and returned to Thales

As 606108-01 but with additional power output pins on SK2 for control panel and TI switch (TPWS functions)



098/016430 Not for new supply - any found in service should be replaced with the latest modification state and returned to Thales

As 606108-02 but fitted with modified logic chip





Catalogue no.



098/016430 Not for new supply - it is recommended that this modification level is returned to Thales for upgrade to latest modification status, especially if the serial number is listed in TIP003

To identify control units tested to TP604415 issue 9 using test software version 4.0


098/016430 Not for new supply - a user of this product may return it for a free upgrade to modification level 4 if they are experiencing AWS reset failures

To identify control units with new build process relay. Will also have blue serial number label and white stripe



098/016430 All AWS receivers listed in this document with the exception of the Unipart Rail electronic receiver7 All alarm and indicator unit types listed in this document All Thales PSU only Howells PSU Catalogue No 062/0146318 All acknowledgement pushbuttons listed in this document

Current supply (at time of publication of this document)

Mark I Not for new supply Used for trial purposes only

Control unit terminal box

Mark 2 606279-00 Thales control units only Control unit mounted externally on terminal box. Terminals for AWS functions only (TPWS functions wired direct to control unit). Links fitted between terminals 9 and 10 and 12 and 16 but not between terminals 4 and 8 to be used for AWS receiver switching.

7 Will function with this item but not tested for compatibility. 8 Control units will function with other non-Thales PSUs, however not warranted as tests for compatibility have not been conducted.





Catalogue no.


Mark II 606840-00 Thales control units only As 606279-00 but with links fitted between terminals 4 and 5, 7 and 8, 9 and 10 and 12 and 16 to emulate original AWS standard wiring.

Mark II 606840-01 098/016425 Thales control units only As 606804-00 but with no internal links between terminals. Any internal links required are to be fitted on installation.

Mark II 606840-02 098/016816 Thales control units only Cable gland for SK1 repositioned to fit Classes 465/2 and 456.

Control unit terminal box

Mark III 606308-00

072/009710 Thales control units only Control unit mounted internally in terminal box. A deeper box than the Mark II with cable entry glands at the same height above base as on AWS junction box/relay unit. Fitted with terminals for all functions. Switching unit card for dual cab operation can be mounted to one side inside the terminal box. Used where public have access or where original installation uses fixed conduit cable entry.

24V nominal 421128

015/011902 Thales control units only9 Stand-alone PSU for 24Vdc vehicle control systems

PSU

72V/96V nominal 421124

098/016429 Thales control units only9 Stand-alone PSU for 72V dc or 96V dc vehicle control systems

9 PSU will function with non-Thales control units, however not warranted as tests for compatibility have not been conducted.





Catalogue no.


608901-xx type EA

Various Compatible with Thales control unit. Not tested with any other manufacturers’ control unit.

‘xx’ denote wide range available with various lengths of cable/conduit. In-line entry with straight Howells type connector.

608902-xx type EB


‘xx’ denote wide range available with various lengths of cable/conduit. In-line entry with straight Litton type connector.

Electronic AWS receiver

608904-xx type EC


‘xx’ denote wide range available with various lengths of cable/conduit. In-line angled entry with straight Howells type connector specifically for Class 158 and 159 vehicles.

100168 Compatible with all electronic control units

Item not manufactured by Thales Sound level 85 – 90 dB

AWS Yodalarm

100398 098/017304 All electronic control units Item not manufactured by Thales Sound level 90 – 95 dB

AWS reset pushbutton/ TPWS acknowledge pushbutton

Panel mounted 386314

098/017166 All electronic control units, AWS receivers and sunflower indicators/ alarm and indicator units

Combined AWS receiver and TPWS aerial

632186-xx type TD

Various Thales control units only Incorporates electronic AWS receiver and TPWS aerial. In line entry, various lengths of cable/conduit. Original AWS receiver mounting. Straight Litton connector.





Catalogue no.


Combined AWS receiver and TPWS aerial

632357-xx type TE

Various Thales control units only Incorporates electronic AWS receiver and TPWS aerial. In line entry, various lengths of cable/conduit. Twin lightweight AWS receiver type mounting. Straight Litton connector.

606245-00 098/016410 Thales control unit only Horizontal orientation with connector on right.

608536-00 064/007231 Thales control unit only Horizontal orientation with connector at rear.

608450-00 Thales control unit only Horizontal orientation with 900mm flying lead.

608450-01 Thales control unit only Vertical orientation with 900mm flying lead.

606245-01 098/016498 Thales control unit only Vertical orientation with connector at bottom.

TPWS control panel

608536-01 015/010957 Thales control unit only Vertical orientation with connector at rear.

606493-00 098/016412 All electronic control units Standard version with provision for lead seal.


608617-00 All electronic control units Fitted with hinged slotted cover to prevent switch operation.

604428-00 (black) Obsolete Any black aerials in service should be replaced by a new yellow one.

TPWS aerial

604428-01 (yellow)

098/016413 No longer supplied. Thales control units only.

Various aerial connector cables available. New aerials now come complete with hard-wired connector cable to improve reliability of previous connectors (see composite aerial harness TPWS assemblies 632140 etc.)





Catalogue no.


632140-xx Various Thales control units only. Straight termination with termination rings at junction box. Various cable/conduit lengths available.

632141-xx Various Thales control units only. Straight Amphenol connector at junction box. Various cable/conduit lengths available.

632142-xx Various Thales control units only. Right-angle Amphenol connector at junction box. Various cable/conduit lengths available.

632143-xx Various Thales control units only. Straight Litton connector at junction box. Various cable/conduit lengths available.

TPWS composite aerial harness assembly

632144-xx Various Thales control units only. Right-angle termination with terminal rings at junction box. Various cable/conduit lengths available.

Amphenol to Amphenol connector 604431-xx

Various Thales control units only. Available as spares only.

Straight Amphenol connector at terminal box end, right-angle Amphenol connector at aerial end. Various lengths according to suffix ‘xx’

TPWS aerial cable

Amphenol to Litton connector 606693-xx

Various Thales control units only - available as spares only.

Litton connector at terminal box end, right-angle Amphenol connector at aerial end. Various lengths according to suffix ‘xx’

TPWS aerial deflector

803429-00 098/016419 Thales TPWS aerial only. Replacement protection dome only.


604444-00 098/016420 Thales TPWS aerial only. Standard junction box with Amphenol connector. No drain hole. Should not be used undrilled on underframe installations. Used also when an additional junction box is needed inside the train.





Catalogue no.


608423-12 Thales control unit only - 12V positive switching.

Includes PEC 608121-12 - not for new supply.

608423-01 098/017958 Thales control unit only - 12V negative switching.

Includes PEC 608121-01 - not for new supply

608423-02 098/017958 Thales control unit only - 12V positive switching.


608423-11 098/017958 Thales control unit only - 12V negative switching


608423-21 098/017958 Thales control unit only 12V negative switching

Includes PEC 608121-21

Dual-cab switching unit kit

608423-22 098/017958 Thales control unit only 12V positive switching

Includes PEC 608121-22


Additional relays for parallel sunflowers - replacement card only - not for new supply

608121-01 - Thales control unit only 12V negative switching

Replacement card only - not for new supply


Replacement card only - not for new supply


Additional relays for parallel sunflowers - not for new supply


Picking relays for improved performance - current production standard at date of issue of this document

Dual-cab switching card


Picking relays for improved performance - current production standard at date of issue of this document

Depot test unit (DTU)

606401-00 Thales control unit only

Train test unit (TTU) Mark I

604617-00 Mark 1 Thales control unit only - no longer available

Uses adaptor attached to trainborne aerial - no facility for TPWS sensitivity test





Catalogue no.


608576-00 - All TPWS installations on standard UK gauge

Kit includes TTU (608527-00) and track-mounted TPWS transmitter loop (608577-00) to transmit to train. Includes output level adjustment for sensitivity test

608756-01 - Broad gauge (1.6m) installations only

Beam for track-mounted transmitter loop to fit 1.6m gauge track

Train test unit (TTU) kit Mark II

608756-02 - All TPWS installations on standard UK gauge

As 608576-00 but with rechargeable batteries in TTU

Table 6 Thales




Unipart item Description/Unipart part no.

Catalogue no.



AWS relay unit



Relay unit junction box



Unipart drawing number NRSTPWS0100

062/014440 Unipart Rail TPWS aerial only All AWS receivers listed in this document All alarm and indicator unit types listed in this document Unipart Rail PSUs and PSU conforming to British Rail Specification 3610 All reset/acknowledgement pushbuttons listed in this document All isolation switches listed in the document

Type 1 Unipart drawing number NRSTPWS0200

062/014441 Unipart Rail control unit only For use in typical multiple unit vehicles in place of older AWS installation in the vehicle roof or other enclosed location. Has terminals for all peripheral equipment

Control unit junction box


062/014449 Unipart Rail control unit only For use in typical multiple unit vehicles in place of older AWS installations in the vehicle roof or other enclosed location. Does not have terminals for all peripheral equipment (which are wired direct to the control unit)

10 Control units will function with Thales PSU however Unipart Rail do not warrant resultant performance as tests for compatibility have not necessarily been conducted.




Unipart item Description/ Unipart part no.

Catalogue no.



062/014450 Unipart Rail control unit only Designed so that the control unit is completely enclosed within the junction box. If used on a dual cab vehicle then dual cab switching unit 062/014450 required.

Control unit junction box

Type 4 Unipart drawing number NRSTPWS0860 Mounting plate Unipart drawing number NRSTPWS0932

062/015993 062/015941

Unipart Rail control unit only Unipart Rail control unit only

Designed so that the control unit is completely enclosed within the junction box. For use where control unit is exposed to the atmosphere and for use on steam locomotives. Type 4 mounting plate enables junction box to be mounted on existing AWS relay unit mounting footprint.

24V dc nominal 062/014453 Unipart Rail and Thales electronic control units

PSU not manufactured by Unipart Rail

72V/96V dc nominal

062/015999 Unipart Rail and Thales electronic control units



Coloured green – with white square modification only

72V/96V dc nominal


Coloured yellow – with white square modification only

PSU


Coloured grey – with white square modification only





Catalogue no.


Electronic AWS receiver


Electronic AWS receiver with TPWS aerial fixing


Electronic AWS receiver complete with flexible conduit

062/010006 to 062/010032


Various products available with different lengths and types of flexible conduit, and with different connector types including conventional AWS connector, MIL-C-5015 connector and hard-wired options.

AWS receiver

Reed receiver 062/010222 to 228


AWS receiver junction box - 5 pin type

Not known 062/000744 All AWS receivers fitted with a 5 pin plug

Coloured green – with white square modification only

Baldwin valve 062/014733 Unipart Rail and Thales electronic control units

Used on locomotives - colour coded green

AWS EP valve

Baldwin valve 062/014737 Unipart Rail and Thales electronic control units

Used on EMU – colour coded blue


EP repeat relay unit


Brake and horn relay unit


AWS isolation switch


AWS/TPWS reset/ acknowledge pushbutton

Dome type 062/014171 Unipart Rail and Thales electronic control units





Catalogue no.


Bulkhead mounting

062/006580 Unipart Rail and some Thales electronic control units

Not compatible with Thales electronic control unit 606108-00 May also be used on steam locomotives using Unipart Rail equipment

AWS Indicator

Flush mounting 062/006610 Unipart Rail and some Thales electronic control units

Not compatible with Thales electronic control unit 606108-00




Solid state device 062/014454 Unipart Rail and Thales electronic control units

AWS bell Not known 062/000280 Unipart Rail and Thales electronic control units

Air horn 070/020843 n/a Removed when TPWS fitted

AWS horn

Vacuum horn 062/006106 n/a Removed when TPWS fitted

Horizontal orientation (Mil-C-5015 Connector) Drawing number NRSTPWS0267

062/014457 Unipart Rail control unit only The horizontal and vertical versions are identical in design and construction, the difference being the orientation of the screen-printing on the front panel.

Vertical orientation (Mil-C-5015 Connector Drawing number NRSTPWS0270

062/014458 Unipart Rail control unit only


Horizontal orientation (enclosed M4 terminals) Drawing number NRSTPWS1118

062/015928 Unipart Rail control unit only The horizontal and vertical versions are identical in design and construction, the difference being the orientation of the screen-printing on the front panel. Variant available with retaining plate and with rear connector.




Unipart item Description/ Unipart Rail part no.

Catalogue no.


Vertical orientation (enclosed M4 terminals) Drawing number NRSTPWS1113


Harsh environment Drawing number NRSTPWS0851

062/015995 Unipart Rail control unit only May be used on steam locomotives

Non-AWS fitted vehicles Drawing number NRSTPWS1000

062/015942 Unipart Rail control unit only Variant for shunting locomotives only (vehicles which do not have AWS fitted)

Spare red LED 062/015947 Unipart Rail control unit only


Spare yellow LED 062/015948 Unipart Rail control unit only

Open with Faston connections Drawing number NRSTPWS0300


Open with screw connections Drawing number NRSTPWS0308


Harsh environment type Drawing number NRSTPWS0857

062/015989 Unipart Rail control unit only For use on steam locomotives

Complete with enclosure Drawing number NRSTPWS1104

092/015957 Unipart Rail control unit only Uses part 062/014443 Faston connections


TPWS isolation unit Drawing. number NRSTPWS1030

062/015943 Unipart Rail control unit only Special for shunting vehicles

TPWS aerial assembly

Drawing. number NRSTPWS0506


0.8 metres Drawing. number NRSTPWS0746

062/015929 Unipart Rail TPWS aerial only

Flexible cable TPWS aerial cable

36 inches Drawing number NRSTPWS0746


Flexible cable




Unipart item Description/ Unipart Rail part no.

Catalogue no.


1.2 metres Drawing number NRSTPWS0746


Flexible cable

48 inches Drawing number NRSTPWS0746


Flexible cable

TPWS aerial cable



Flexible cable



Flexible cable TPWS aerial cable



Flexible cable

Drawing. number NRSTPWS0906


Various aerial connector cables available. May be used on steam locomotives.


With integral aerial cable Drawing number NRSTPWS1017


For use with shunting locomotives only

TPWS aerial mounting plate

Drawing number NRSTPWS0502


TPWS aerial hood/cover



Air type 062/014173 Unipart Rail and Thales electronic control unit only

Colour coded grey Change end/isolation switch

Air type 062/014174 Unipart Rail and Thales electronic control unit only

Colour coded grey Operating handle with violet end cover


062/015983 Unipart Rail control unit only 110Vdc variant for use with control unit junction box type 4

TPWS dual cab switching unit

PC board 062/014451 Unipart Rail control unit only For use with control unit junction box type 4

TPWS aerial switching unit



Table 7 Unipart Rail




Part 3 Guidance on maintenance and fault finding 3.1 Maintenance requirements 3.1.1 General

3.1.1.1 Adhering to the specified maintenance procedures will assure AWS system reliability. Maintenance is a combination of equipment self-testing, routine test and inspection, and, where required, replacement and/or overhaul. Maintenance of AWS and TPWS is specified in the appropriate vehicle maintenance instructions. Vehicle maintenance instructions should always be followed by the maintainer.

3.1.1.2 Maintenance of AWS and TPWS equipment serves the following objectives:

a) To ensure equipment continues to function as required.

b) To ensure equipment operates within specified limits.

c) To ensure equipment is not damaged and remains securely attached to the vehicle.

d) To ensure height critical equipment (for example AWS receiver and TPWS aerial) remains within permitted height range.

3.1.1.3 Specific AWS test equipment is now available for maintenance activities to supplement the traditional hand-held magnet testing. The test equipment (see section 3.2) enables a more comprehensive set of tests to be conducted to aid maintenance as well as fault finding.

3.1.2 Manufacturers recommended maintenance requirements 3.1.2.1 The various manufacturers of AWS equipment provide a minimum recommended

maintenance requirement for their equipment. These requirements will have been considered in the production of vehicle maintenance instructions (the manufacturers recommended maintenance requirements are mainly of use to those tasked with creating vehicle maintenance instructions). It should be noted that the manufacturers maintenance instructions do not always reflect the operating duty cycle of equipment, which varies depending on the vehicles it is fitted to, or service experience, and hence the vehicle maintenance instructions may differ from the manufacturers’ recommended maintenance regime and the vehicle maintenance instructions should always be complied with.

a) Details of Howells Railway Products’ recommended AWS maintenance requirements are not available at the time of publication of this document.

b) Details of STS’ recommended AWS and TPWS maintenance requirements are not available at the time of publication of this document.

c) Thales’ recommended AWS and TPWS maintenance requirements are documented in Thales Handbook Number 1395-1-G. Equipment testing is detailed in Thales document PTP604412-00.

d) Unipart Rail’s recommended AWS and TPWS maintenance requirements are documented in NRSSPECXSA003/11.




3.1.3 Component tracking application 3.1.3.1 The component tracking application is a web-based computer application

operated by the Association of Train Operating Companies (ATOC) and designed to enable the rail industry to accurately track AWS and TPWS inter-vehicle component fitment and defect histories. The system performs a key role in enabling the industry to manage AWS and TPWS performance and operators are encouraged to make full use of it for recording defects and tracking components and vehicle fitment. The more it is used then the better the data will be.

3.1.3.2 The system is available for use by railway undertakings (train operators), train maintainers, component suppliers and component overhaulers/repairers. The application can be found on the ATOC engineering portal at www.clyx.net/atoc and will require a login and password. Further details and instructions on use of the application are contained in ATOC Approved Code of Practice ACOP/EC/01001.

3.1.3.3 To ensure that useful data is generated by the component tracking application, all component defects, changes or other reasons for repair should be entered into the application. All serial numbered items of AWS equipment should be returned to their overhauler/repairer with a printed copy of the defect report that is generated by the component tracking application (a blank printed example of a defect report form is attached as Appendix J).

3.1.3.4 Whenever an AWS component is found to be defective, the maintainer undertaking the fault finding and repair should record the information shown in Appendix K. This can then be entered into the component tracker application. It is important that the maintainer records whether the AWS test equipment has been used and what the findings are.

3.1.3.5 The application also enables warranty claims to be generated and submitted to the component overhauler/repairer in an agreed format.

3.1.4 Component life expectancy 3.1.4.1 Reliability of AWS and TPWS in service can be improved if the equipment

maintenance includes pre-emptive replacement/overhaul on a specified periodicity. The optimum periodicity for AWS and TPWS component overhaul has been developed from engineering assessments (formerly published by ATOC as Code of Practice ACOP/EC/01001). These can be found in Appendix G.

3.1.4.2 In order to benchmark AWS and TPWS failure data, it is recommended that the overhaul/renewal of AWS/TPWS equipment is carried out against the periodicities specified in Appendix G. For the majority of equipment this will result in a renewal at C4. It may be practicable to carry out this renewal at C6 for certain components but there is currently insufficient data to justify any extension of periodicities. Also, certain new items (such as solid-state control units and AWS receivers) do not yet have adequate performance data, so these are currently specified as renew on failure.

3.1.4.3 For those AWS items where the recommended overhaul periodicity is set at C4, once there has been a campaign change of AWS equipment individual operators may choose to change certain items on multiples of C4 (for example every second C4). Note that the campaign change out only applies to existing AWS components. New AWS components do not require a campaign change. Prior to campaign change/scrapping of components, it is essential that railway undertakings (train operators) and members of the AWS supply chain ensure that an adequate float of new components exists.




3.1.4.4 Following completion of the TPWS national fitment programme, certain items of AWS equipment have been removed from some classes of train and new TPWS components installed in their place. The components that will have been removed are retained in Appendix G as they may remain on a small number of vehicles. In addition, Appendix G contains specific components with overhaul periodicities yet to be determined. These are included for completeness and because several are intended to be included in an ATOC/RIA (Railway Industry Association – suppliers) traceability programme.

3.1.4.5 The components listed and their recommended overhaul periodicities will be reviewed in the future as better performance data becomes available via the component tracking application. If a new AWS or TPWS component is developed for service it is essential that railway undertakings (train operators) and/or members of the supply chain inform Rail Safety and Standards Board and the ATOC engineering director. This will ensure the accuracy of information within this document and that the component tracking application is maintained up to date.

3.1.4.6 It is recommended that target service life and similar markings be removed from each item of AWS equipment that is presently date coded. The removal of date coding information should be carried out by the overhauler. Each component already displays a manufacturers’ serial number which is normally in the form of a six digit number.

3.1.5 Maintenance of test equipment 3.1.5.1 Railway undertakings (train operators) are responsible for the maintenance of

depot test equipment required to ensure that AWS and TPWS equipment functions as required. Available depot test equipment and their maintenance requirements are detailed in section 3.2 below.

3.2 AWS depot test equipments 3.2.1 A number of AWS equipment manufacturers and suppliers have developed

specific AWS test equipment for use during routine maintenance and when diagnosing faults at maintenance depots. Test equipment includes track-mounted and hand-held permanent test magnets to check the functionality of the equipment, and specific AWS test equipment to exercise individual components and check wiring as well as check the functionality of the trainborne equipment. The test equipment may or may not be combined with TPWS test equipment.

3.2.2 Depot hand-held AWS permanent test magnets 3.2.2.1 Unipart Rail supply a hand-held AWS permanent test magnet for use in depot

testing (Figure 52). The hand-held magnet (British Rail Catalogue number 062/008833) is simply waved under the AWS receiver to simulate the receiver passing over track-mounted magnets. Waving the south pole (blue) of the test magnet simulates a caution/stop signal and waving the south pole (blue) followed by the north pole (red) simulates a clear signal aspect.

3.2.2.2 Testing using the hand-held magnet is mainly used for functional testing at maintenance exams or following equipment replacement. If there is any doubt about the receiver sensitivity, then the recently developed STS test equipment should be used (see 3.3.3).

3.2.2.3 No specific maintenance is required on the hand-held AWS depot test magnet.




Figure 52 Unipart Rail hand-held AWS permanent test magnet

3.2.3 Depot track-mounted AWS permanent test magnets 3.2.3.1 Railway undertakings (train operators) are responsible for ensuring that trains

leaving maintenance locations have a fully operative AWS system. To help meet this requirement, GE/RT8035 requires certain maintenance locations to have an AWS permanent test magnet(s) mounted in the track which the train preparer or train driver will use to test that the AWS operates and applies the train brakes before a train goes into service. Currently, two manufacturers provide depot test magnets in both standard and extra strength versions.

3.2.3.2 Unipart Rail supply AWS depot track-mounted permanent test magnets (Figure 53). Two magnetic field strength variants are available, a standard strength magnet (coloured yellow) and an extra strength magnet (coloured green). These magnets can be attached to timber sleepers or concrete sleepers.

Figure 53 Unipart Rail AWS depot track-mounted permanent test magnet

3.2.3.3 Vortok International supply AWS depot track-mounted permanent test magnets. They are made from rare-earth metal providing an extremely consistent, calibrated magnetic field. Two variants are available, a standard strength magnet (Figure 54 coloured yellow) and an extra strength magnet (Figure 55 coloured green).

3.2.3.4 These magnets can be attached to timber sleepers or concrete sleepers, or suspended from the foot of the rail using GRP beams supplied by Vortok, but are not suitable for fitting on steel sleepers. The magnets are designed to provide the minimum field strength required by GE/RT8035. They should be installed such that the top of the magnet surface is in line with the rail heads. Each magnet should be supplied with a certificate of conformity which should be retained on the asset file.

3.2.3.5 The standard strength magnets are calibrated by the manufacturer to provide a magnetic field strength of 3.1 - 3.5 mT at 115 mm ARL for the standard strength magnet, and 4.7 - 5.1 mT at 193 mm ARL for the extra strength magnet. These values are specified in GE/RT8035 which should be referred to in case of future change.




Figure 54 Vortok standard strength depot test magnet on fixed mount

Figure 55 Vortok extra strength depot test magnet on moveable mount

3.2.3.6 Maintenance of the Vortok depot test magnet should consist of an annual inspection to ensure that there is no physical damage or looseness to the magnet or its fixings, removal of any ferrous material collected by the magnet, and a check that the top of the magnet is at rail head height using a non-conducting straightedge laid across both rails (Figure 56). If at the correct height, the top surface of the magnet will just touch the straightedge. If the magnet is too high or too low, then it can be adjusted by unlocking the locknut and rotating the magnet to raise or lower it to the correct height, tightening the locknut afterwards.

Figure 56 Checking the height of magnet

3.2.3.7 Although not a requirement of the manufacturer, the magnetic field strength of the magnets may be measured to ensure they are still within the permitted range specified in GE/RT8035. A suitable magnetic flux density meter is a calibrated Cermag Gaussmeter type GMET H001, which can be sourced direct from Cermag or from Vortok. This must be used with a non-metallic spacer and the flux pattern should be checked within a 50 mm circle from the centre of the magnet.




3.2.3.8 The depot test magnet should be replaced with a re-calibrated unit in accordance with the manufacturer’s recommendations. Old magnets should be returned to Vortok to be re-calibrated.

3.2.3.9 As both types of magnet are of a high strength, certain safety precautions are recommended before approaching or handling them. Watches, credit cards and any other magnetically sensitive materials should not be brought near the magnets. Staff with pacemakers or other medical aids should not approach or handle the magnets.

3.3 AWS test equipment 3.3.1 Former British Rail AWS test units

3.3.1 Level 1 (on train AWS test unit British Rail Catalogue number 870/024901) and Level 2 (off train alarm and indicator test unit British Rail Catalogue number 870/025001) purpose built test equipment have been supplied in the past for testing AWS systems and equipment. This test equipment is likely to be superseded by the later test equipment detailed below.

3.3.2 STS - TY287 AWS tester 3.3.2.1 STS manufacture a portable AWS tester known as the TY287 AWS tester, under

licence from Rail Safety and Standards Board Limited. This equipment can be used for routine maintenance testing and for fault diagnosis purposes.

3.3.2.2 The TY287 AWS tester is designed to be used as a diagnostic tool to test AWS receivers from the cab of the vehicle. It can identify the sensitivity of the receiver and confirm its correct operation. Use of this equipment will help to significantly increase the reliability of testing and hence reduce the costs associated with no fault found on AWS equipment returns.

3.3.2.3 Unlike the hand-held magnet that it replaces, it is capable of providing repeatable testing of the trainborne AWS system, using test criteria determined by the operator. It can be used in a maintenance depot, with a vehicle standing over a pit or on a ballasted track, without the vehicle actually moving. It will, as far as is practical, accurately simulate service conditions of track-mounted AWS magnets.

3.3.2.4 The tester accommodates the simulation of the vehicle travelling at a range of pre-selected speeds over a sequence of magnetic fields, the fields simulating the appropriate distance/time spacing present on the rail network.

3.3.2.5 It is recognised that the AWS system does have tolerance from both an infrastructure sub-system and trainborne sub-system perspective, with the trackside equipment generally providing higher fields than the minimum required by the specification or simulated by the AWS tester. Therefore, under normal circumstances, the trainborne equipment could be less sensitive and still appear to operate satisfactorily in service.

3.3.2.6 The AWS tester can be used for proactively investigating reported AWS receiver faults. It can also be used as a maintenance tool where permitted by the vehicle maintenance instructions.

3.3.2.7 The AWS tester produces a magnetic field equal to the minimum strength specified in GE/RT8035 for the AWS permanent and electro-magnetic track magnets, with due allowance for the maximum distance of the receiver from the track magnet position when correctly installed in the track.

3.3.2.8 The AWS tester is self-powered, can be used with all types of AWS receivers, is suitable for one man operation and is capable of maintenance calibration by the user.




3.3.2.9 Principal components:

a) Handset (Figure 57) – a rugged hand-held unit with an LED alphanumeric display and control pushbuttons connected to the equipment housing such that it can be operated from within the vehicle’s cab.

b) Flux generator (Figure 58) – mounted on a lightweight frame which enables easy positioning under the vehicle’s AWS receiver.

c) Equipment case – a robust enclosure which facilitates ease of handling and is suitable for use in outdoor and indoor locations. Along with the handset and connecting cables, it houses the rechargeable sealed lead acid battery and the electronics which generate the appropriate flux.

Figure 57 STS TY287 AWS tester

Figure 58 STS flux generator positioned under a vehicle’s AWS receiver

3.3.2.10 Technical specification:

a) Either standard or extra strength AWS track magnets can be selected and the equipment can replicate the following AWS track magnet scenarios in Table 8:

Separate south Approaching a signal at caution giving a horn signal

Separate north New AWS track equipment laid in, but not in use and traction cables, which can result in fields comparable with legitimate fields.

Separate south north Approaching a clear signal giving a bell signal

Separate north south Occurring in bi-directional sites where the train is proceeding towards a signal at caution. The train equipment should respond with a horn plus brake. It will also occur on simplified bi-directional lines, when there is a line side AWS cancelling indicator provided

Separate north south north Track fault on bi-directional sites

Table 8 AWS track magnet scenarios




3.3.2.11 It is possible to carry out tests at higher or lower magnetic field strengths for comparative testing. Power levels are based on GE/RT8035 minimum values at 100%. The selectable power levels are:

a) For standard magnets: 50%, 70% to 150% in 10% steps and 200%

b) for extra strength magnets: 70%, 80%, 90%, 95%, 100%, 105%, 110%

3.3.2.12 The available speed selections are:

a) For standard magnets: 20, 40, 60, 80, 90, 100, 110, 125 mph

b) For extra strength magnets; 20, 40, 60, 80, 90, 100 mph

3.3.2.13 All four parameters can be changed independently using the handset buttons.

3.3.2.14 Operation of the STS AWS test box is described in Appendix O.

3.3.2.15 Maintenance of the AWS tester is limited to visual inspection for any obvious damage or mal-operation of the equipment, which should be investigated.

3.3.3 AWS receiver characterisation unit 3.3.3.1 In addition to the TY287 AWS tester, STS are developing an AWS receiver

characterisation test equipment for use in benchmarking the ‘as installed’ performance of an AWS receiver on any particular fleet type. The equipment will be available for use to undertake a ‘first of class test’ against which routine maintenance or fault finding tests can be compared. At the time of publication of this issue of this document, the equipment is still in the development stage. Further details of this equipment and procedures will be included when available.

3.3.4 Thales 3.3.4.1 Thales manufacture a combined AWS and TPWS test box, known as the Thales

depot test unit (DTU). The Thales DTU (Figure 59) is a portable unit powered from the vehicle under test for verifying the correct functioning of circuits external to the AWS/TPWS control unit. The DTU is capable of exercising and confirming the correct operation of the PSU, AWS receiver, AWS alarm and indicator unit, reset pushbutton and of simulating a brake demand.

3.3.4.2 The DTU switches, on demand, signals to operate the AWS visual and audible indications and has LED indicators to confirm the operation of the AWS controls. The correct PSU operation is also indicated by visual indicators on the DTU.

3.3.4.3 Operation of the DTU is described in Appendix Q.

3.3.4.4 Maintenance of the DTU consists of visual inspection for any obvious damage or mal-operation of the equipment, which should be investigated, and calibration in accordance with the manufacturer’s recommendations.

Figure 59 Thales DTU




3.3.5 Unipart Rail 3.3.5.1 Unipart Rail manufacture a hand-held combined AWS and TPWS test equipment

(Unipart Rail hand-held TPWS signal generator, test coil and lead, Catalogue number 062/005298). The test equipment (Figure 60), known as the Unipart Rail depot test unit (DTU) enables the maintainer to exercise the TPWS equipment to simulate the receipt of signals from track-mounted TPWS transmitter loops.

3.3.5.2 Operation of the DTU is detailed in Appendix O.

3.3.5.3 Maintenance of the DTU consists of visual inspection for any obvious damage or mal-operation of the equipment, which should be investigated, and calibration in accordance with the manufacturer’s recommendations.

Figure 60 Unipart Rail hand-held combined AWS/TPWS test equipment

3.4 TPWS test equipment 3.4.1 TPWS test equipment manufacturers

3.4.1.1 A number of TPWS equipment manufacturers have developed specific TPWS test equipment for use during routine maintenance and when diagnosing faults at maintenance depots. Some of the test equipment is combined with AWS test equipment.

3.4.3 Thales depot test unit (DTU) 3.4.3.1 Thales manufacture a combined AWS and TPWS test box, known as the Thales

depot test unit (DTU) (Figure 61). The DTU is a portable unit powered from the vehicle under test for verifying the correct functioning of circuits external to the AWS/TPWS control unit. The DTU is capable of exercising and confirming the correct operation of the PSU, TPWS aerial, TPWS driver’s control panel, TPWS acknowledge pushbutton, TPWS temporary isolation switch and of simulating a brake demand.

3.4.3.2 Operation of the DTU is described in Appendix Q.

Figure 61 Thales DTU




3.4.4 Thales train test unit (TTU) 3.4.4.1 Thales also manufacture a train test unit (TTU) kit for testing the trainborne

TPWS functions (Figure 62). The Mark II TTU is a portable, battery-operated unit for functional testing of the OSS/TSS functions using a standard TPWS track-mounted transmitter loop mounted at track level below the vehicle. The equipment can be operated by one person from the driving cab.

3.4.4.2 The TTU generates (Figure 63), on demand, sequences of TPWS transmissions to simulate the movement of the train over TPWS transmitter loops under various conditions.

3.4.4.3 The track-mounted transmitter loop (Figure 64) is energised from the TTU and generates an electromagnetic field strength at the TPWS frequencies, that can be varied from that equivalent to an operating level of 300 mT at 300 mm ARL to a value below the minimum detectable level for a typical TPWS control unit.

3.4.4.4 The response of the trainborne TPWS equipment can be checked by the indicators on the vehicle under test.

3.4.4.5 Operation of the TTU is detailed in Appendix S.

3.4.4.6 Maintenance of the TTU consists of visual inspection for any obvious damage or mal-operation of the equipment, which should be investigated, and calibration in accordance with the manufacturer’s recommendations.

3.3.4.7 Certain of the TTU versions are fitted with rechargeable batteries, indicated by a suitable label. If there is no label present indicating this then the batteries are not of the rechargeable type.

Figure 62 Thales TTU unit kit

Figure 63 Thales TTU




Figure 64 Thales TTU track-mounted transmitter loop

3.4.2 Unipart Rail 3.4.2.1 Unipart Rail manufacture a hand-held combined AWS and TPWS test box

(Unipart Rail hand-held TPWS signal generator, test coil and lead, Catalogue number 062/005298). The test box (Figure 65), known as the Unipart Rail depot test unit (DTU) enables the maintainer to exercise the TPWS equipment to simulate the receipt of signals from track-mounted TPWS transmitter loops.

3.4.2.2 Operation of the DTU is detailed in Appendix R.

3.4.2.3 Maintenance of the DTU is limited to visual inspection for any obvious damage or mal-operation of the equipment, which should be investigated. The test equipment should be returned to Unipart Rail for calibration in accordance with the manufacturer’s recommendations.

Figure 65 Unipart Rail hand-held combined AWS/TPWS test box

3.5 Fault and failure management 3.5.1 General

3.5.1.1 The AWS and TPWS systems are mandatory safety systems and form a primary safety system aimed at preventing and mitigating signals passed at danger (SPADs). Hence, failed AWS or TPWS trainborne equipment is liable to import safety risk to the railway. It is vital that this risk is managed properly both on the operating railway, and by taking appropriate management steps to assure system configuration, reliability and availability. There are a number of mandatory Railway Group Standards that apply to managing trainborne equipment failures and these are outlined below. However, it is the railway undertakings (train operators’) responsibility to ensure that they operate an overall safety management system that complies with these minimum mandatory requirements.

3.5.2 Requirements of the Rule Book 3.5.2.1 The Rule Book Module TW5, mandates the conditions for managing trainborne

AWS or TPWS sub-system failures for trains entering service or when AWS or TPWS fails on a train already in service.

3.5.2.2 Trains are not permitted to enter service if AWS or TPWS is isolated (or the isolation device seal is broken) in any cab required to be used.




3.5.2.3 Trains with AWS or TPWS that fails in service and are managed in accordance with the railway undertakings (train operators’) contingency plan (see section 3.3.3). If there is a competent person available to accompany the driver then the train may proceed at normal speed, otherwise the train may only proceed at a maximum speed of 40 mph.

3.5.3 Requirements of other standards 3.5.3.1 GO/RT3437 requires that railway undertakings (train operators) have a

contingency plan in place to manage trains operating in service which suffer a failure of train safety systems including AWS and/or TPWS. The contingency plan should set out the responses the train operator will take should AWS or TPWS fail in service. This will include the locations where passengers will be detrained, the train re-marshalled or taken out of service, or other appropriate action taken.

3.5.3.2 GE/RT8250 describes arrangements:

a) Monitor safety performance of rail vehicles.

b) Report, record and analyse all defects in rail vehicles that may affect safety or safe inter-working between operators, and take the necessary corrective action.

c) Formally report and share information relating to high-risk (safety related) defects, including those requiring urgent action, and take the necessary corrective action.

3.5.3.3 In addition, GK/RT0106 sets out specific requirements for managing safety related failures of signalling systems which includes the AWS and TPWS trainborne sub-system. Similar to GE/RT8250, this standard requires processes to be in place for:

a) Recording and investigating safety related failures.

b) Monitoring failure rates.

c) Improving safety performance.

3.5.3.4 GK/RT0106 requires an appropriate response depending on the level of risk, and categorises AWS failure modes by risk as shown in Table 9.

3.5.3.5 It should be noted that an AWS fault code 3 has traditionally been considered as a right side failure. However, potential failure mechanisms that could lead to this state include failure of the trainborne AWS receiver to detect the track permanent magnet and if the signal was at caution or danger then this would be a Code 7 wrong side failure. Hence, it is recommended that AWS code 3 failures are considered as ‘dormant wrong side failures’ and investigated in a similar manner.

3.5.4 Railway undertakings (train operator) processes 3.5.4.1 Railway undertakings (train operators) should operate a system of defect

reporting, recording and monitoring in order that the safety performance of their vehicles can be monitored and corrective action taken if faults and adverse safety trends develop. AWS and TPWS faults and failures should be included within such a system to permit the adequacy of AWS and TPWS equipment design, manufacture and maintenance arrangements to be determined. The system should differentiate the response based on the risk from the defect, for example a right-side failure or wrong-side failure, as indicated in Table 9.

3.5.4.2 Performance monitoring is also required to enable compliance with the AWS and TPWS minimum performance targets quoted in GE/RT8035 and GE/RT8030.




a) GE/RT8035 requires the AWS trainborne sub-system to achieve the following availability level:

‘Trainborne AWS equipment shall have an availability of not less than 99.9%. This target shall be met on a ‘per fleet, per year’ basis, not on a ‘per train, per failure’ basis (for example the total time or mileage that trains are in service when diagnosed as having faulty AWS equipment, but before being taken out of service in accordance with GO/RT3437, shall amount to not more than 0.1% of the total in-service time or mileage). A fleet for the purposes of this document constitutes all the AWS-fitted trains that a train operator owns or leases.’

b) GE/RT8030 requires the TPWS trainborne sub-system to achieve the following availability level:

‘The trainborne sub-system shall have an availability of not less than 99.9%. This target shall be met on a ‘per fleet, per year’ basis, not on a ‘per train, per failure’ basis (for example the total time or mileage that trains are in service when diagnosed as having faulty TPWS equipment, but before being taken out of service in accordance with GO/RT3437, shall amount to not more than 0.1% of the total in-service time or mileage). A fleet for the purposes of this document constitutes all the TPWS-fitted trains that a train operator owns or leases.’

3.5.4.3 Railway undertakings (train operators) should also endeavour to provide feedback to the fault originator in order to more closely involve drivers with fault reporting and rectification. By providing such feedback, drivers will be more likely to report faults in future and may provide an enhanced level of detail if their understanding of the cause and effect is improved.

Failure classification RT3185 fault code

Cab audible/visual indication

Signal/warning condition Safety

related (high risk)

Safety related (low risk)

Negligible direct risk

1 Horn and bell when clear indication expected

Clear signal

2 Horn instead of bell when clear indication expected

Clear signal

3 No Horn or bell when clear indication expected

Clear signal Possible dormant wrong side failure

4 Bell and horn when warning indication expected

Adverse signal or warning

5 Bell instead of horn when warning indication expected


Wrong side failure

6 Brake without horn when warning indication expected


7 No indication or brake when warning indication expected


Wrong side failure




Failure classification RT3185 fault code

Cab audible/visual indication

Signal/warning condition

Safety related (high risk)

Safety related (low risk)

Negligible direct risk

7a Audible warning received but indicator did not change to yellow and black


Wrong side failure

8 Horn when no indication expected

Not at signal or warning

9 Bell when no indication expected

Not at signal or warning

10 Unable to cancel At any time

11 Indicator not changing to all black

Any signal or warning

12 AWS failed to arm At any time Wrong side failure

13 AWS failed to disarm At any time

14 ATP/TVM failed to arm NOT AWS/TPWS NOT AWS TPWS

15 ATP/TVM failed to arm NOT AWS/TPWS NOT AWS TPWS

16 TPWS failed to activate Signal at danger or OSS at speed restriction or buffer stops

Wrong side failure

17 TPWS operated when not required

At any time

Table 9 AWS/TPWS fault codes

3.5.5 Urgent high risk defects 3.5.5.1 The recently introduced IT application NIR-Online (www.nir-online.net) provides a

process of showing urgent high-risk defects in accordance with the requirements of GE/RT8250.

3.5.5.2 If a railway undertaking discovers an urgent high risk defect in an AWS or TPWS component that warrants an urgent campaign check, then it is likely that other railway undertakings (train operators) are affected as the equipment is common across many users. Hence, the GE/RT8250 process should be enacted for such AWS and TPWS defects discovered.

3.5.6 Initial fault reporting 3.5.6.1 AWS and TPWS faults are most likely to be detected by drivers who will report

this to the signaller who will allocate a fault code as required by the Rule Book. The nature of the fault will be reported using form RT3185 (see Appendix H). Form RT3185 will also be used by signallers if the AWS or TPWS fault is a wrong side fault in order that the trainborne and trackside equipment will be tested.

3.5.6.2 Form RT3185 may be supplemented with an entry in the vehicle defect log book and/or via the train management system depending on the railway undertakings (train operators) policy and the type of vehicle involved.




3.5.6.3 Additionally, faults may be detected by analysis of train data recorders.

3.5.6.4 The fault code is dependent upon the cab audible/visual indication and/or the signal/warning condition in operation at the time that the fault occurred.

3.5.6.5 AWS and TPWS faults are further classified as either 'wrong side failures' or 'right side failures'. AWS fault codes 5 and 7 are categorised as AWS wrong side failures, for example the system failed to caution the driver when it should have done so. AWS fault code 12 is also a wrong side failure but will only be applicable to systems that are suppressed when another train protection system is in operation. It is also recommended that the wrong side failure procedure is invoked for fault code 3 (no horn or bell when clear indication expected) which is considered to present a dormant wrong side failure.

3.5.6.6 TPWS fault code 16 is categorised as a TPWS wrong side failure, for example the train brakes were not applied by TPWS when required to do so.

3.5.6.7 All other fault codes are considered to be right side failures, for example the fault gave the driver a spurious caution indication or spurious brake demand, and are not considered a significant risk.

3.5.6.8 Specific procedures are required to be followed for wrong side failures which must be treated with the utmost importance.

3.5.7 Process for investigating reported right side failures 3.5.7.1 The process depicted in Figure 66 is recommended to reduce the incidence of no

fault found due to external influences following a right side failure report, and is recommended in light of the new technologies that have been produced for fault diagnosis.

3.5.7.2 Various equipments exist to conduct a full AWS and/or TPWS test as described in section 3.2 and Appendices N to T.

3.5.7.3 Depot test procedures as laid down in vehicle maintenance instructions should be followed. If any item is identified as the cause of the fault then it should be removed (and sent for repair) and a new item refitted. If the reported fault can be repeated but changing the suspected faulty item does not cure the fault, then the fault is likely to be in the vehicle wiring which may need to be insulation tested if no obvious faults can be identified (see 3.3.11).

3.5.7.4 After removing and/or changing any equipment, a full AWS and/or TPWS test should be conducted before releasing vehicles back into service.




Figure 66 AWS/TPWS right side failure investigation process




3.5.8 Process for investigating reported wrong side failures 3.5.8.1 The process depicted in Figure 67 below is recommended to reduce the

incidence of wrongly diagnosed faulty equipment due to external influences, and is recommended in light of the new technologies that have been produced for fault diagnosis. This process relies on use of approved test equipment such as the STS TY287 AWS tester.

Figure 67 AWS wrong side failure investigation process




3.5.8.2 It has become common practice to send the control unit and AWS receiver to an approved technical investigation centre following a reported AWS code 5 or 7 failure as the equipment is often assumed to have suffered a wrong side failure. However, in many cases the technical investigation centres are unable to find any faults with equipment under investigation. In some cases, reported AWS code 5 or 7 failures have been caused by the trackside AWS equipment or by traincrew errors.

3.5.8.3 Similarly for TPWS, alleged wrong side failures may be due to track-mounted equipment faults, driver error or operational circumstances as identified in the common causes sections.

3.5.9 Managing defective components 3.5.9.1 Defective AWS and TPWS components should be managed in accordance with

the railway undertakings (train operators) quality procedures in order that defective components are segregated, stored, labelled, packaged and despatched for repair or scrap as appropriate. Specific packaging should be used where provided for high value, fragile and/or repairable items, for example, control units, voltage converters and alarm and indicator units.

3.5.9.2 As an example, faulty items of AWS and TPWS equipment which have been involved in a right side failure should be treated as follows:

a) The equipment must be adequately packed, using special packaging where available and have the correct label attached prior to dispatch (see Appendix V for an example label). The correct label for equipment other than that changed as a result of a 'wrong side failure’ is coloured yellow and has the wording 'AWS/TPWS equipment for repair'.

b) Equipment changed as a result of a 'right side failure’ should be sent to the appropriate repair agent for repair.

3.5.9.3 Faulty items of AWS and TPWS equipment which have been involved in a wrong side failure should be treated as follows:

a) The equipment must be adequately packed, using special packaging where available and have an appropriate label identifying the urgent nature of the package attached prior to dispatch (see Appendix V for an example wrong-side failure label). A 'wrong side failure report form' (see Appendix U for an example) should also be enclosed in the package. A copy of the form should also be faxed to the investigation centre in advance of the package being despatched.

b) Equipment changed as a result of a wrong side failure should be sent for technical investigation to an approved, competent body. It is expected that a competent technical investigation body will provide detailed feedback to the railway undertaking (train operator) on the nature of the defects found, as this may require further action on behalf of the railway undertaking (train operator) on his fleet and ‘urgent’ advice being given to other operators (see Appendix U for an example feedback form).

c) It is essential that equipment being sent for technical investigation and/or repair should be properly labelled and accompanied by sufficient information to enable the investigators or repairers to properly diagnose and rectify faults.




3.5.10 Component history 3.5.10.1 As part of the railway undertakings (train operators) monitoring system it is very

important that the nature of the defect and the fault found are accurately and comprehensively recorded in order that subsequent data analyses are meaningful and useful. Railway undertakings (train operators) are recommended to operate a vehicle and/or AWS/TPWS component history system such that the recent vehicle history with regards to AWS or TPWS faults can be tracked, and trends in AWS/TPWS performance can be monitored. ATOC manages a computerised component tracking application system on behalf of railway undertakings (train operators), which allows details of AWS and TPWS equipment to be recorded, component fault histories to be generated and supports analysis of equipment performance. This application is available for use by railway undertakings (train operators) from the ATOC website engineering portal.

3.5.11 Fault finding techniques 3.5.11.1 Traditionally, AWS faults have been diagnosed using an AWS hand-held test

magnet waved under the receiver to simulate the train passing over the AWS track magnets and hence function the system (see Appendix M). Functioning the AWS system with a hand-held test magnet has the advantage of easily and quickly testing the AWS trainborne sub-system. Replacement of key components is undertaken to remedy the fault having tracked down the likely faulty component using a systematic process, in part using test equipment. This overall approach is still valid today but more sophisticated test equipment is now available (see section 3.2) to supplement the basic functional test, thus allowing faults to be detected and healthy equipment to be identified more reliably.

3.5.11.2 For all fault finding techniques, some basic checks should be undertaken first:

a) Check the vehicle records and component tracker system to determine whether the vehicle has been involved in any AWS related incident within the last 12 months.

b) Measure and record the height of the bottom of the AWS receiver above rail level. This should be within the limits applicable to the vehicle concerned (as specified in the vehicle maintenance instruction). Note that standard electro-mechanical AWS receivers are mounted within the range 133 mm to 171 mm above rail level, Thales electronic AWS receiver height range is 100 mm above rail level minimum, to 210 mm above rail level maximum (refer to section 2.6.8). Adjust as necessary (on vehicles where adjustment is provided).

It should be noted that standard strength AWS receivers running over high strength track magnets are normally set to the top of the permitted height range to avoid spurious right side failures by detecting high magnetic fields generated by cross-track traction cables, but if set too high can result in wrong side failures.

Further, the TY287 ‘characterisation unit’ may be used to adjust the generic receiver height tolerance for particular vehicles.

c) Examine items of equipment for possible causes of intermittent fault, for example external damage, loose connectors, water ingress to connectors.

3.5.11.3 The fault diagnosis procedures should enable faulty equipment to be reliably diagnosed. If a fault persists, for example 2 repeat failures in 3 months, but cannot be traced by functional testing or use of the various test equipment, or an earth fault is suspected, then wiring checks should be carried out to trace any possible wiring faults:




a) Visually examine as far as is possible all items of the AWS/TPWS trainborne sub-system carefully for possible causes of an intermittent fault, for example external damage, loose connectors, water ingress or defective wiring.

b) Disconnect wiring connectors from components likely to be affected by insulation testing, for example the AWS receiver, TPWS aerial, AWS alarm and indicator units (if fitted) and bells(s)/Yodalarm/horn (if fitted), AWS/TPWS control unit, TPWS driver’s control panel, EP repeat relay (if fitted), EP valves (if fitted) and voltage converter (refer to relevant vehicle instructions).

c) Using an insulation tester (500 or 1000 volt), check that the cable insulation resistance between AWS/TPWS cables and all other cables running with them (refer to vehicle wiring diagrams) is not less than 10MΩ (wire to wire and wire to earth).

d) Using an insulation tester, check that the cable insulation resistance between each AWS/TPWS cable and the vehicle chassis is not less than 10MΩ.

3.5.11.3 Section 3.5.12 provides further guidance on possible fault causes and guidance is provided on the application of various fault finding techniques and system testing in Appendices M to T:

a) Fault diagnosis during power up sequence and during service operation.

b) Functional testing using AWS hand-held test magnet.

c) Testing using AWS and TPWS depot test equipment.

3.5.11.4 Appendix T contains a typical fault finding test sheet on which the results of a fault finding test can be recorded.

3.5.11.5 In addition, data from train data recorders and train management systems may both offer data related to the operation and performance of both the AWS system and the train control systems at the time of the fault. When fault finding, consideration should be given to downloading data and analysing the data to assist in fault finding. These systems may also directly log the nature of the fault depending on the complexity of the installation.

3.5.11.6 Data from a train data recorder (Figure 68) may also enable determination of any driver errors that may have led to an unintended (spurious) automatic brake application by AWS. For example, a reported spurious brake demand could be due to late operation of the AWS reset pushbutton, or holding down the AWS reset pushbutton before the system detects the track magnet south pole. The sequence and timing of these actions could be identified from train data recorder. See overleaf for an example train data recorder output.

3.5.11.7 Further, it may not always be apparent that a reported AWS or TPWS trainborne fault could be the symptom of an infrastructure fault. For example, an AWS fault code 8 (horn when no indication expected) could be due to the AWS receiver on the train detecting a magnetic flux from a cross-track cable during a cable fault.

3.5.11.8 Data from train management systems may also provide a precise location (for example Ordnance Survey Grid Reference) to be provided to the infrastructure manager to investigate.




Figure 68 Example train data recorder output

3.5.12 Guide to possible fault causes 3.5.12.1 A guide to possible causes and remedies for AWS/TPWS failures associated with

combined electronic AWS/TPWS control unit AWS system is given in Figures 69 and 70 below. These flowcharts are based on the power up and self-test routine, follows a sequence from power up of the system through the equipment automatic self-test routine. These flowcharts have been published for information purposes only and do not take precedence over approved vehicle maintenance and fault finding procedures.

3.5.12.2 Appendix L provides an example of applying these guides to create fleet specific guidance (the example in Appendix L is an AWS and TPWS fault finding guide for freight locomotives).

Clear signal indications (pink line)

Caution Signal Indications (red line)

AWS/TPWS full isolation switch operated (gold line)

TPWS performing ‘self-test’ when cab desk ‘opened’




AWS Code 1HORN & BELL

POSSIBLE CAUSE SPURIOUS SWITCHING OF AWS RECEIVER

SOLUTION CHANGE: AWS RECEIVER & CABLE

AWS Code 2HORN INSTEAD OF BELL

POSSIBLE CAUSE

WRONG SIDE FAILURE

AWS Code 3NO INDICATION INSTEAD OF BELL

POSSIBLE CAUSE

AWS Code 4BELL & HORN

POSSIBLE CAUSE

WRONG SIDE FAILURE

AWS Code 5BELL INSTEAD OF HORN

POSSIBLE CAUSE

AWS Code 6BRAKE WITHOUT HORN

POSSIBLE CAUSE

AWS Code 8HORN INSTEAD OF NO INDICATION

POSSIBLE CAUSE

AWS Code 9BELL INSTEAD OF NO INDICATION

POSSIBLE CAUSE

AWS Code 10UNABLE TO CANCEL

POSSIBLE CAUSE

AWS Code 11SUNFLOWER NOT ALL BLACK

POSSIBLE CAUSE

RANDOM FAULTS: INDICATE AWS Rx

FAILURES AT SAME LOCATION: INDICATES WEAK AWS MAGNETS

SOLUTIONCHECK: AWS RECEIVER

HEIGHT IS CORRECT, testCHANGE: AWS RECEIVER & CABLE (TPWS PUT would show if it is a 12v PSU fault)

IF NO CODE 7 OBSERVED, THEN BELL FAULT

SOLUTION IF PUT OK THEN CHANGE ALARM & INDICATOR/BELL

POSSIBLY CAUSED BY AN OLD AWS RECEIVER USED IN AREAS WITH STRONG AWS TRACK MAGNETS

SOLUTION CHECK AWS RECEIVER HEIGHT IS CORRECT, IF

CORRECT CHANGE RECEIVER

PERMANENT RESET VOLTAGE ON AWS Rx

SOLUTION CHECK: ACK BUTTON FOR SHORT CIRCUIT. IF OK

CHANGE CONTROL UNIT

HORN FAILURE (should be noticed during PUT)

SOLUTION CHANGE ALARM & INDICATOR UNIT/HORN, IF NOT FIXED THEN CHANGE

CONTROL UNIT

WRONG SIDE FAILURE

AWS Code 7NO HORN OR BRAKE

POSSIBLE CAUSE AWS RECEIVER HAS FAILED TO DETECT

PERMANENT MAGNET

SOLUTIONCHECK: AWS Rx HEIGHT,

IF CORRECT THEN CHANGE AWS RECEIVER

(AWS cable fault would cause a Code 2)

WRONG SIDE FAILURE

AWS Code 7aSUNFLOWER NOT YELLOW/BLACK

POSSIBLE CAUSE SUNFLOWER FAILURE (should be noticed during

PUT)

SOLUTIONCHANGE: ALARM & INDICATOR UNIT/

SUNFLOWER, THEN CONTROL UNIT IF

PROBLEM NOT FIXED

AWS RECEIVER FAILURESOLUTION CHANGE: AWS RECEIVER

& CABLE

SPURIOUS AWS RECEIVER OPERATION – eg. Response to a trackside traction cable

SOLUTION TRAINBORNE EQUIPMENT NOT AT FAULT

MANY POSSIBLE CAUSESPOSSIBLE DRIVER ERROR WHEN ACK. (CHECK TDR)

SOLUTIONCHANGE: AWS RECEIVER & CABLE, test CONTROL UNIT, test ACK BUTTON,

TEST ALARM & INDICATOR UNIT/SUNFLOWER

SUNFLOWER FAILURE (should show up during PUT)

SOLUTION CHANGE ALARM & INDICATOR/SUNFLOWER,

IF NOT FIXED THEN CHANGE CONTROL UNIT

WRONG SIDE FAILURE

AWS Code 16TPWS FAILED TO ACTIVATE

POSSIBLE CAUSE AERIAL POSITION COULD BE INCORRECT, OR TRACKSIDE FAULT

SOLUTION CHECK: AERIAL LOCATION, PERFORM TTU

TEST, IF OK, CHECK TRACKSIDE LOCATION

AWS Code 17UNREQUIRED TPWS OPERATION

POSSIBLE CAUSE CAUSED BY ACK BUTTON PRESSED LATE, OR

TRACK INTERFERENCE IN TRIP LOCATION

SOLUTION CHECK: BRAKE WIRING, CHANGE CONTROL UNIT

IF BRAKES DO NOT RELEASE

Figure 69 Combined AWS/TPWS fault finding guide




DOES THE SYSTEM POWER UP ?

DOES THE SUNFLOWER CHANGE TO YELLOW &

BLACK? ARE THE 3 TPWS LAMPS ILLUMINATED

DOES THE SUNFLOWER TURN BLACK ?

DOES THE HORN SOUND AFTER 1.5s ?

PRESS & HOLD ACK BUTTON. DOES

SUNFLOWER CHANGE TO YELLOW & BLACK ?

RELEASE THE ACK BUTTON. DOES THE HORN

STOP AND THE 3 TPWS LAMPS GO OUT ?

IS THE TEMP ISOLATION FAULT LIGHT FLASHING?

DO THE BRAKES RELEASE?

CHECK WIRING/ CONNECTORS TO TPWS

POWER SUPPLY AND MASTER SWITCH

CONTACT AND TPWS ISOLATION SWITCH

NO

NO

NO

NO

NO

YES

NO

LAMPS DO NOT ILLUMINATE

SUNFLOWER DOESN’T CHANGE CHECK WIRING/

CONNECTORS TO SUNFLOWER

CHECK WIRING/ CONNECTORS TO TPWS

CONTROL PANEL

CHECK WIRING/ CONNECTORS TO AWS

RECEIVER AND SUNFLOWER

CHECK WIRING/ CONNECTORS TO BELL &

HORN AND POWER SUPPLY

CHECK WIRING/ CONNECTORS TO

SUNFLOWER, POWER SUPPLY & ACK BUTTON

CHECK WIRING/ CONNECTORS TO AWS Rx,

ACK BUTTON, ALARM & INDICATOR AND POWER

SUPPLY

WAS AERIAL OVER AN ACTIVE LOOP (CHECK TDR)? IF NOT CHECK

WIRING/ CONNECTORS TO TPWS AERIAL AND

JUNCTION BOX

CHECK BRAKE WIRING/ CONNECTORS AT

CONTROL UNIT

PERSISTENT FAULT

PERSISTENT FAULT

PERSISTENT FAULT

PERSISTENT FAULT

PERSISTENT FAULT

PERSISTENT FAULT

PERSISTENT FAULT

PERSISTENT FAULT

PERSISTENT FAULT

REPLACE:POWER SUPPLY UNIT if

12V or 40V not present

REPLACE: SUNFLOWERTEST: CONTROL UNIT

REPLACE: TPWS CONTROL PANEL

TEST: CONTROL UNIT

REPLACE: AWS CABLE & RECEIVER (if no 0v & 12V

O/P from Rx)TEST: SUNFLOWER &

CONTROL UNIT

REPLACE: BELL & HORNTEST: POWER SUPPLY (if no 12V) & CONTROL UNIT

REPLACE: ACK BUTTONTEST: SUNFLOWER,

POWER SUPPLY (if no 40V) & CONTROL UNIT

REPLACE: AWS RECEIVER & CABLE

TEST: POWER SUPPLY & CONTROL UNIT

REPLACE: TPWS AERIAL FLEXIBLE CONDUIT

TEST: TPWS AERIAL, AERIAL JUNCTION BOX &

CONTROL UNIT

REPLACE: CONTROL UNIT

Figure 70 Combined AWS/TPWS system fault finding flowchart




3.5.13 Common AWS and TPWS failure mechanisms 3.5.13.1 Some common AWS and TPWS failure mechanisms are described below. These

have been identified from system performance monitoring and are categorised into human error (Table 10), system faults (Table 11) and trainborne sub-system equipment faults (Table 12).

3.5.13.2 Human Error Drivers may report AWS or TPWS faults (or the equipment may be found isolated) due to external events that are not specific faults of the trainborne equipment. Examples of this are shown in Table 10.

Initial fault report Possible human error cause

Unwarranted AWS brake application Driver error in not resetting AWS within the specified caution acknowledgement period

AWS fault code 10 (unable to cancel) Driver error by holding down the AWS reset pushbutton before the AWS caution audible tone is sounded

TPWS fault code 17 (TPWS operated when not required)

Over-speeding on OSS for signal or PSR TPWS not temporarily isolated when required TPWS TSO not operated or timed out before passing signal at danger with authority

Table 10 Common human error type faults

3.5.13.3 System faults Experience of operating with AWS and TPWS has highlighted a number of ‘system issues’ that result in an apparent AWS or TPWS fault as perceived by the driver. These should be read in conjunction with the trainborne sub-system faults, as shown in Table 11.

3.5.13.4 Trainborne sub-system faults With respect to trainborne sub-system faults, as the significant majority of vehicles are fitted with Thales TPWS equipment (95%), most known failure mechanisms identified below only affect this system. However, as the Unipart Rail and STS equipment has accumulated a much lower comparative mileage, it is considered that there is insufficient data available to be certain that such faults, or other faults, will not arise in these systems. Common trainborne sub-system faults are identified in Table 12.




Type of fault Possible system cause

AWS fault code 2 (horn instead of bell when clear indication expected)

Faulty track magnet (for example electromagnet fault or field strength out of specification) AWS receiver on the train marginal sensitivity or mounted too high or passing over magnet at extreme of suspension movement

AWS fault code 7 (no indication or brake when warning indication expected) – WRONG SIDE FAILURE

Faulty track magnet (for example permanent magnet field strength out of specification)

AWS fault code 8 (horn when no indication expected)

AWS Fault Code 9 (Bell when no indication expected)

Trainborne equipment detecting a strong magnetic field from non-AWS trackside infrastructure, for example high currents, passing through cross-track traction cables

AWS fault code 10 (unable to cancel) A cab is opened up with the AWS receiver directly over an AWS magnet

AWS failed system power up test A cab is opened up with the AWS receiver directly over an AWS magnet

TPWS failed system power up test A cab is opened up with the TPWS aerial directly over an active TPWS transmitter loop

TPWS fault code 16 (TPWS failed to activate) – WRONG SIDE FAILURE

Faulty TPWS transmitter loop

TPWS fault code 17 (TPWS activated when not required) (symptom is flashing fault light)

Brake demand due to trainborne equipment detecting valid sequence of signals when travelling reverse direction over TSS (applies to Thales modification 0 control units only) Trainborne equipment detecting TPWS frequencies from trackside infrastructure, specifically the harmonics of certain TI-21 track circuit transmitters (higher risk if TPWS aerial is ahead of the leading axle) TPWS OSS still active for main aspect when movement controlled by subsidiary signal (solution suppress OSS when subsidiary signal off) TPWS ‘self-reversion’ due to TPWS TSS re-activated before TPWS aerial clear of transmitter loops Trainborne equipment wrongly interpreting OSS transmitter loop lobes as main field at low speed at terminal stations (solution implemented – buffer stops mini-loops)

Table 11 Common system faults




Type of fault Possible trainborne equipment cause

AWS fault code 1 (horn and bell when clear indication expected)

Spurious switching of AWS receiver - solution renew AWS receiver and cable.

AWS fault code 2 (horn instead of bell when clear indication expected)

AWS receiver faults - solution check AWS receiver height is correct, if ok renew AWS receiver and cable.

AWS fault code 3 (no indication instead of bell)

AWS alarm and indicator or bell fault - solution change alarm and indicator unit or bell.

AWS fault code 4 (bell and horn when warning indication expected)

Reed AWS receivers operating over extra-strength magnets are believed to have operated for years with old relay based logic units masking a timing error. The introduction of electronic AWS/TPWS control units has revealed this timing error with a resultant increase in AWS code 4 failures - solution check AWS receiver height is correct. Consider replacing reed AWS receiver with an electronic solid state AWS receiver.

AWS fault code 5 (bell instead of horn) WRONG SIDE FAILURE

Permanent reset voltage on AWS receiver due to short circuit on AWS reset pushbutton or faulty control unit - solution change reset pushbutton if faulty, if not change control unit.

AWS fault code 6 (brake without horn)

AWS alarm and indicator or horn fault - solution change alarm and indicator unit or horn, if not fixed change control unit.

AWS fault code 7 (no indication or brake when warning indication expected) WRONG SIDE FAILURE

AWS receiver failed to detect track magnet - solution check AWS receiver height and renew receiver if height correct.

AWS fault code 8 (horn when no indication expected)

AWS receiver failure - solution renew AWS receiver and cable.

AWS fault code 10 (unable to cancel) If Thales control unit then check modification status. If not modified strike 4 or above then replace and return to Thales.

AWS fault code 11 (indicator not changing to ‘all black’)

AWS alarm and indicator or sunflower fault - solution change alarm and indicator unit or sunflower, if not fixed change control unit.

TPWS fault code 16 (TPWS failed to activate) WRONG SIDE FAILURE

TPWS aerial not correctly located (movement due to poor application of Loctite on aerial retention assembly) but electrically still connected to control unit – recommended solution is to install a composite aerial harness which has a mechanical location.

Failure of TDR to record AWS/TPWS outputs

Failure of control unit TDR output relay volt-free contacts soft--sticking due to inrush current damage. Change control unit.




Type of fault Possible trainborne equipment cause

AWS/TPWS brake application delay POSSIBLE CAUSE OF WRONG SIDE FAILURE

If Thales control unit then internal brake demand relay failure (sticking armature) – check modification strike 2 or above, replace and return to Thales if not

Flashing fault lights on drivers control panel

Intermittent connection problem between TPWS aerial and connecting cable (solutions are to replace the aerial/cable connector arrangement with a hard wired aerial or improve the securing mechanism for the aerial/cable interface) Check the aerial for continuity. For Thales equipment, check between pins 2 and 5 (110 - 130Ω typical) and between pins 3 and 4 (15 – 21 Ω typical). Replace aerial if an open circuit is found or the DMM reading falls outside the typical range.

Table 12 Common trainborne equipment faults




Appendix A Useful contacts Company Address Website Telephone

No Comment

Association of Train Operating Companies (ATOC)

Floor 3 40 Bernard Street London WC1N 1BY

www.atoc.org 0207 8418000

Train operator representative body

Cermag Ltd 92/94 Holywell Road Sheffield S4 8AS

www.cermag.co.uk 0114 2446136

Suppliers of Gaussmeters

Howells Railway Products Ltd

Longley Lane Sharston Industrial Estate Wythenshawe Manchester M22 4SS

www.howells-railway.co.uk

0161 9455567

Manufacturer and supplier of AWS trainborne equipment

Railpart UK Ltd PO Box 159 Denison House Doncaster DN4 0DB

www.railpart.co.uk 01302 342414

AWS/TPWS component stock manager

Siemens Transportation Systems

www.siemens.com Manufacturer of AWS/TPWS specific transmission module

STS Signals Ltd Doulton Road Cradley Heath West Midlands B64 5QB

www.sts-signals.com 01384 858521

Manufacturer and supplier of TPWS and AWS products and services (including former Field and Grant products)

Thales UK Limited, Land and Joint Systems

Manor Royal A Building Crawley West Sussex RH10 9PZ

www.thalesgroup.com www.TPWS.co.uk

General: 01293 528787 Helpline: 07977 241602

Manufacturer and supplier of TPWS and AWS products and services

Unipart Rail Gresty Road Crewe Cheshire W2 6EH

www.natrail.com 01270 533000

Manufacturer and suppliers of TPWS and AWS products and services

Vehicle Train Control System Interface Committee AWS Working Group

Rail Safety and Standards Board Evergreen House 160 Euston Road London NW1 2DX

www.rssb.co.uk/sysic.asp

0207 904 7518

Industry body to determine solutions to AWS issues based on sound technical and economical evaluation

Vortok International Ltd

6 – 8 Haxter Close Belliver Industrial Estate Roborough Plymouth Devon PL6 7DD

www.vortok.co.uk 01752 700601

Suppliers of AWS depot test magnets




Appendix B Typical AWS/TPWS electrical installation on single cab vehicle

This schematic is shown as a typical example of a TPWS/AWS installation and should not be used for any purpose other than for general information. Reference should be made to the approved electrical schematics for each vehicle type for use in maintenance, fault finding and repair activities.

PRINT ON A3




Appendix C Typical AWS/TPWS electrical installation on a dual cab vehicle

This schematic is shown as a typical example of a TPWS/AWS installation and should not be used for any purpose other than for general information. Reference should be made to the approved electrical schematics for each vehicle type for use in maintenance, fault finding and repair activities.

PRINT ON A3




Appendix D STS AWS/TPWS vehicle interface details This appendix details the electrical interface specification for the STS TPWS/AWS equipment as known at the publication date of this document. Reference should be made to approved vehicle diagrams and manufacturers’ data when undertaking maintenance, fault finding and repair activities.

Twin-lightweight AWS receiver identifies the multiple connector pin identification letter.

Connections Detector

No. Contact Connector indication pin

1 South R

1 North S

1 Common N

2 South R

2 North S

1 Common P

Reset circuit: positive T 1 and 2

0V U

AWS LED alarm and indicator unit identifies the multiple connector pin identification letter. Note all screens are connected together within the indictor unit. Pin G provides, when required, an auxiliary input to control the display to ‘all black’ (derived from the +12.5V dc output on pin J).

Connections

Pin Wire/screen Circuit

A Wire Black control signal

N Screen For pin A

B Wire Supply +12.5V dc

C Wire Supply 0V dc

D Wire Black/yellow control signal

F Wire Input +40V dc reset control

R Screen For pin F

G Wire Black control signal (auxiliary)

S Screen For pin G

H Wire Output +40V dc reset signal

T Screen For pin H

J Wire Output +12.5V dc

M Wire Output power off/fault detector

V Screen For pin M




Appendix E Thales AWS/TPWS vehicle interface details This appendix provides details of connector types, the electrical interface specification and the timer link settings for the Thales TPWS/AWS equipment as known at the publication date of this document. Reference should be made to approved vehicle diagrams and manufacturers’ data when undertaking maintenance, fault finding and repair activities.

The connectors used on the AWS/TPWS system mating with supplied equipment are shown in the Table below. (Note that connectors are Litton unless otherwise stated):

Equipment Ref. Description Part no.

Control unit PL1 Free socket FRCIR08F28-21S F80T12-15 ABCIRHSE06T2821SCNF80

Control unit SK2 Free plug FRCIR08F28-21P F80T12-15 ABCIRHSE06T2821PCNF80

PSU PL1 Free socket FRCIR06F18-12S F80T12-15 ABCIRHSE06T1812SCNF80

PSU SK2 Free plug FRCIR06F22-14P F80T12-15 ABCIRHSE06T2214PCNF80

Alarm and indicator unit

Free socket FRCIR06F22-14S F80T12-15 ABCIRHSE06T2214SCNF80

Twin lightweight or electronic receiver or ducting

Fixed socket FRCIR030CFZ22-14S F80T12-15 ABCIRH03T22-14SCNF80

TPWS control panel PL1 Free socket (straight)

Amphenol T3105-501 (R/A T3105-581)

All Litton or AB connectors to the control unit should be fitted with an radio frequency interference grounding system. A suitable connector for clamping multiple cable screens to the shell body is the Litton FRCRG08RED28-21P F80T12-15. Alternatively the screened backshell, POLAMCO series 70 EMI/RFI backshell, POLAMCO part number 70Q3-28-16-I-2B can be used with the usual Litton or AB connector.

The following table defines the function and interface specification of each connection on all Thales AWS/TPWS equipment:

Connector pin Function Signal type/remarks

Combined AWS and TPWS control unit

PL1/L 12V + Power +12V

PL1/K 12V - Power 0V

PL1/R 40V + Power +40V

PL1/J 40V - Power 0V

PL1/N Rx north 12V signal

PL1/M Rx south 12V signal

PL1/V Set sunflower to yellow/black 12V signal






PL1/W Set sunflower to all black 12V signal

PL1/X Bell 12V signal

PL1/Z Horn 12V signal

PL1/P AWS acknowledge/reset 40V signal

PL1/A Brake out Volt-free contact (RL13)

PL1/C Brake in Volt-free contact (RL13)

PL1/b TDR clear annunciated a Volt-free contact (RL11)

PL1/c TDR clear annunciated b Volt-free contact (RL11)

PL1/d TDR restrictive annunciated a Volt-free contact (RL12)

PL1/e TDR restrictive annunciated b Volt-free contact (RL12)

PL1/f TDR set to all black a Volt-free contact (RL5)

PL1/m TDR set to all black b Volt-free contact (RL5)

PL1/j TDR set to yellow/black a Volt-free contact (RL4)

PL1/k TDR set to yellow/black b Volt-free contact (RL4)

PL1/g TDR AWS acknowledge pressed a Volt-free contact (RL1)

PL1/h TDR AWS acknowledge pressed b Volt-free contact (RL1)

PL1/n TDR brake demand a Volt-free contact (RL8)

PL1/p TDR brake demand b Volt-free contact (RL8)

PL1/r TDR TPWS isolated a Volt-free contact (RL7)

PL1/s TDR TPWS isolated b Volt-free contact (RL7)

PL1/T Vigilance reset a Volt-free contact (RL9)

PL1/U Vigilance reset b Volt-free contact (RL9)

PL1/a Acknowledge timer link Pulled up to +12V

PL1/S Acknowledge timer link 0V return

SK2/A Aerial + Analogue signal

SK2/B Aerial - Analogue signal

SK2/C Aerial test + Analogue signal

SK2/D Aerial test - Analogue signal

SK2/H RF Mon output + Analogue signal

SK2/J RF Mon output - Analogue signal

SK2/a TI OFF SW input 12V signal

SK2/b TI ON SW input 12V signal






SK2/b TI ON SW input 12V signal

SK2/d TSO LED 6V signal

SK2/e Brake demand LED 6V signal

SK2/f TI/fault LED 6V signal

SK2/g TSO SW input 12V signal

SK2/h TDR wrong direction loop a Volt-free contact (RL3)

SK2/j TDR wrong direction loop b Volt-free contact (RL3)

SK2/k TDR normal direction loop a Volt-free contact (RL2)

SK2/m TDR normal direction loop b Volt-free contact (RL2)

SK2/n TDR TSO active a Volt-free contact (RL6)

SK2/p TDR TSO active b Volt-free contact (RL6)

SK2/r TDR temporary isolation fault indicator a

Volt-free contact (RL10)

SK2/s TDR temporary isolation fault indicator b

Volt-free contact (RL10)

SK2/K OS timer bit 2 link Pulled up to +12V

SK2/L OS timer bit 2 link 0V return

SK2/M OS timer bit 1 link Pulled up to +12V

SK2/N OS timer bit 1 link 0V return

SK2/P OS timer bit 0 link Pulled up to +12V

SK2/R OS timer bit 0 link 0V return

SK2/S TSO timer link Pulled up to +12V

SK2/T TSO timer link 0V return


PL1/B 12V + Power +12V

PL1/C 12V - Power 0V

PL1/J 12V - Power 0V

PL1/D Set to yellow/black 12V signal

PL1/A Set to all black 12V signal

PL1/L Bell 12V signal

PL1/V Horn 12V signal

PL1/F Proving contact 40V signal

PL1/H Proving contact 40V signal





TPWS PSU

PL1/A Supply in +ve Train supply

PL1/B Supply in +ve Train supply

PL1/C Supply in –ve (72/96V) Train supply

PL1/D Supply in –ve(48V) Train supply

PL1/E Rx2 select Train supply voltage

PL1/F Supply in –ve (24V) Train supply

SK2/A 12V+ Power +12V

SK2/B 12V+ Power +12V

SK2/C 12V+ Power +12V

SK2/D 12V+ Power +12V

SK2/E 12V+ Power +12V

SK2/N 12V+ Power +12V

SK2/P 12V+ Power +12V

SK2/R 12V+ Power +12V

SK2/K 12V- Power 0V

SK2/L 12V- Power 0V

SK2/M 12V- Power 0V

SK2/U 12V- Power 0V

SK2/F 40V+ Power +40V

SK2/G 40V+ Power +40V

SK2/H 40V- Power 0V

SK2/S 40V- Power 0V

SK2/J Rx1 output To AC receiver

SK2/T Rx2 output To DC receiver

SK2/V Receiver supply in Power +12V

Standard AWS receiver

Pin 1 12V+ Power +12V

Pin 2 Rx north 12V signal

Pin 3 Rx south 12V signal

Pin 4 Reset 40V signal

Pin 5 40V- Power 0V





Twin lightweight AWS receiver

Pin N Rx1 (ac lines) Power +12V

Pin P Rx2 (dc lines) Power +12V

Pin U 40V- Power 0V

Pin T Reset 40V signal

Pin S Rx north 12V signal

Pin R Rx south 12V signal

Combined electronic AWS receiver and TPWS aerial

Pin N Rx1 (ac lines) Power +12V

Pin P Rx2 (dc lines) Power +12V

Pin U 40V- Power 0V

Pin T Reset 40V signal

Pin S Rx north 12V signal

Pin R Rx south 12V signal

Pin L Analogue output high 0.4V/mT approx. into 20 KΩ

Pin M Analogue output low 0.4V/mT approx. into 20 KΩ

Pin V Cable screen

Pin A Aerial + Analogue signal

Pin B Aerial - Analogue signal

Pin C Aerial test + Analogue signal

Pin D Aerial test - Analogue signal

Pin E Cable screen

TPWS aerial

Pin 1 Aerial screen Screen (train chassis)

Pin 2 Aerial + Analogue signal

Pin 5 Aerial - Analogue signal

Pin 3 Aerial test + Analogue signal

Pin 4 Aerial test - Analogue signal

Driver’s panel

PL1/1 TSO LED 6V signal

PL1/2 Brake demand LED 6V signal

PL1/3 TI/fault LED 6V signal

PL1/4 LED return (12V-) Power 0V

PL1/5 TSO SW input 12V signal

PL1/6 Switch return (12V+) Power +12V





Temporary isolation switch



Pin 23 TI OFF SW input 12V signal

Pin 13 TI ON SW input 12V signal

Depot test unit

PL6/A Brake control

PL6/C Brake control

PL6/J PSU 40V-

PL6/K PSU 12V-

PL6/L PSU 12V-

PL6/M AWS south

PL6/N AWS north

PL6/P Reset pushbutton

PL6/R PSU 40+

PL6/V Set yellow/black

PL6/W Set all black

PL6/X Bell

PL6/Z Horn

PL6/a ACK link

PL6/S ACK link return

SK6/A Aerial +

SK6/B Aerial -

SK6/C Aerial test +

SK6/D Aerial test -

SK6/a TI switch OFF

SK6/b TI switch ON

SK6/d TSO lamp

SK6/e Brake lamp

SK6/f TI/fault Ind. lamp

SK6/g TSO switch

SK6/K ST2 link

SK6/L ST2 link return





Depot test unit

SK6/M ST1 link

SK6/N ST1 link return

SK6/P ST0 link

SK6/R ST0 link return

SK6/S TSO link

SK6/T TSO link return

SK6/U 12V -

SK6/X 12V +

SK6/W 12V +

SK6/Z 12V +

SK6/V 12V -

Timer link settings The control unit contains three timers which can be set to different values by inserting a combination of five links across pairs of pins in the control unit mating connectors (SK1 and PL2) or across the appropriate terminals in the control unit terminal box. The location, link settings and pin outs for each timer on both Mark II and Mark III and no terminal box installation types are given in Tables F.3, F.4, F.5 and F.6 (• indicates a fitted link). Note that for installations that have a Mark II and Mark III terminal box fitted, multiple links are achieved by daisy chaining links between pin numbers shown and 12V- (terminal 33).

Acknowledge TSO OSS Installation type

TB SK1 TB PL2 TB PL2

No terminal box

Mark II terminal box

Mark III terminal box

Timer setting (s) No terminal box link between CU SK1/a and S

Mark II/III terminal box - terminal 35 linked to 33

2.7

2.0




Timer setting (s) No terminal box or Mark II terminal box link between CU PL2/S and T

Mark III terminal box - terminal 34 linked to 33

60

20

No terminal box or Mark II terminal box link fitted between PL2 pins shown

Mark III terminal box - terminals shown linked to terminal 3

Timer setting (ms)

P and R(ST0)

M and N(ST1)

K and L (ST2)

38 (ST0)

37 (ST1)

36 (ST2)

974 (passenger)

1218 (goods)

Note that the link combinations have been chosen such that, for any timer setting, failure of a link will increase the time, thereby reducing the OSS set speed.

Electronic AWS receiver sensitivity settings The 5-way connector version is factory wired for a particular sensitivity setting specified when ordering (H1 suffix for standard and H2 suffix for de-sensitised). For the 19-way Litton connector version, the sensitivity is determined by the train wiring to pins N and P and may be switched between the two settings if required as indicated in the table below.

Fixed sensitivity Switch sensitivity

Pin Standard mode Desensitised mode

Standard mode Desensitised mode

N 12V+ N/C 12V+ 12V+ (see note)

P N/C 12V+ N/C 12V+

Note: It is not recommended that pin N is disconnected for desensitised mode as this could give spurious warnings on change-over.




Appendix F Unipart Rail AWS/TPWS vehicle interface details This appendix details the connector types and electrical interface specification for the Unipart Rail TPWS/AWS equipment as known at the publication date of this document. Reference should be made to approved vehicle diagrams and manufacturers’ data when undertaking maintenance, fault finding and repair activities. The tables below contain details on:

Electrical load details for the brake control output.

Electrical interface details for the fixed socket.

Electrical interface details for the plug.

Electrical wiring details for the control unit junction boxes types 1, 3 and 4.

Electrical wiring details for the control unit junction box type 2.

Electrical interface details for the driver’s control panel.

Electrical interface specification for the TPWS temporary isolation switch.

Electrical interface specification for the TPWS isolation unit.

Electrical connection details for the TPWS aerial junction box.

Electrical connection details for the TPWS aerial cable assembly.

Electrical connection details for the TPWS aerial switching unit.

Electrical connection details for the dual cab switching unit.

The correct mating half-connectors for the AWS/TPWS control unit are manufactured by AB connectors with the part number:

Plug - ABCIRHSE06T-28-21PCN-F80-V0

Socket – ABBCIRHSE06T-28-21SCN-F80-V0

Voltage (V dc) Current (A dc) Load

12 10 Resistive

12 10 Inductive, L/R = 7 ms

24 10 Resistive

24 5 Inductive, L/R = 7 ms

70 1.8 Resistive

70 1.1 Inductive, L/R = 7 ms

110 0.6 Resistive

110 0.4 Inductive, L/R = 7 ms




Socket connector reference

Function Type Electrical interface specification

SK1 - A TPWS aerial input +ve Input Aerial signal

SK1 – B TPWS aerial input –ve Input Aerial signal

SK1 - C TPWS aerial output +ve Output Aerial test signal

SK1 – D TPWS aerial output –ve Output Aerial test signal

SK1 - E

SK1 – F

SK1 – G

SK1 – H

SK1 – J

SK1 – K Must not be used

SK1 - L 0 volts output for link Output PSU zero volts 100mA max.

SK1 - M Must not be used

SK1 – N 0 volts output for link Output PSU zero volts 100mA max.

SK1 – P OSS timer control Input

SK1 – R 0 volts output for link Output PSU zero volts 100mA max.

SK1 – S TSO timer control Input

SK1 – T 0 volts output for link Output PSU zero volts 100mA max.

SK1 – U 0 volts for DCP Output PSU zero volts 250mA max.

SK1 – V

SK1 – W 12 volt output to DCP Output 12 volts 100mA max.

SK1 – X 12 volt output to TIS Output 12 volts 100mA max.

SK1 – Z 12 volt output to TIS Output 12 volts 100mA max.

SK1 - a TI normal input from TIS Input 12 volts 100mA max.

SK1 – b TI isolate input from TIS Input 12 volts 100mA max.

SK1 – c

SK1 – d TSO output to DCP Output 6 volts at 45mA

SK1 – e Brake demand to DCP Output 6 volts at 45mA

SK1 - f TI/Fault to DCP Output 6 volts at 45mA






SK1 – g TSO input from DCP Input 12 volts 100mA max.

SK1 – h TDR (wrong direction loop)

VFC 110 volts 10mA max.

SK1 – j TDR (wrong direction loop)

VFC

SK1 – k TDR (correct direction loop)

VFC 110 volts 10mA max.

SK1 – m TDR (correct direction loop)

VFC

SK1 – n TDR (TSO on) VFC 110 volts 10mA max.

SK1 – p TDR (TSO off) VFC

SK1 – r TDR (TI/fault indicated) VFC 110 volts 10mA max.

SK1 - s TDR (TI/fault indicated) VFC



PL1 - A Brake output relay VFC

PL1 – B

PL1 - C Brake output relay VFC

PL1 – D

PL1 - E

PL1 – F

PL1 – G

PL1 – H

PL1 – J 40 volt dc input -ve Input PSU 40 volts negative

PL1 – K 12 volt dc input -ve Input PSU 12 volts negative

PL1 - L 12 volt dc input +ve Input PSU 12 volts positive

PL1 - M Receiver input south Input

PL1 – N Receiver input north Input

PL1 – P Input from reset button Input

PL1 – R 40 volt dc input +ve Input PSU 40 volts positive

PL1 – S 0 volt brake delay timer Output

PL1 – T Vigilance reset relay VFC 110 volts10mA maximum






PL1 – U Vigilance reset relay VFC

PL1 – V Indicator to yellow/black Output 12 volts

PL1 – W Indicator to all black Output 12 volts

PL1 – X Chime (bell) output Output 12 volts

PL1 – Z Horn output Output 12 volts

PL1 - a Brake delay timer input Input

PL1 – b TDR (AWS clear) VFC 110 volts 10mA max.

PL1 – c TDR (AWS clear) VFC

PL1 – d TDR (AWS caution) VFC 110 volts 10mA max.

PL1 – e TDR (AWS caution) VFC

PL1 – f TDR (indicator to all black)

VFC 110 volts 10mA max. (with PL1 – m)

PL1 – g TDR (AWS acknowledge) VFC 110 volts 10mA max. (with PL1 – m)

PL1 – h TDR (AWS acknowledge) VFC 110 volts 10mA max.

PL1 – j TDR (indicator to yellow/black)

VFC

PL1 – k TDR (indicator to yellow/black)

VFC 110 volts 10mA max. (with PL1 – f)

PL1 – m TDR (indicator to all black)

VFC

PL1 – n TDR (brake demand) VFC 110 volts 10mA max.

PL1 – p TDR (brake demand) VFC

PL1 – r TDR (TI) VFC 110 volts 10mA max.

PL1 – s TDR (TI) VFC




Terminal no.

Function Connector detail

1 AWS bell output SK1/X

2 North input from AWS receiver SK1/N

3 South input from AWS receiver SK1/M

4

5

6 40 volt power supply 0V SK1/J

7 40 volt power supply +40V SK1/R

8

9 12 volt power supply 0V (link to terminal 33) SK1/K

10

11 12 volt power supply +12V (link to terminal 32) SK1/L

12 AWS horn output (link to terminal 16) SK1/Z

13 AWS indicator to all black SK1/W

14 AWS indicator to yellow/black SK1/V

15 AWS reset pushbutton input SK1/F

16 (Link to terminal 12)

17 Brake output relay SK1/A

18 Brake output relay SK1/C

19

20 TPWS aerial input +ve PL1/A

21 TPWS aerial input -ve PL1/B

22 TPWS aerial test output +ve PL1/C

23 TPWS aerial test output -ve PL1/D

24

25

26 Input from TSO switch in DCP PL1/g

27 Output to TSO indicator in DCP PL1/d

28 Output to brake demand indicator in DCP PL1/e

29 Output to TI/fault indicator in DCP PL1/f

30 Temporary isolation normal input from TIS PL1/a

31 Temporary isolation isolate input from TIS PL1/b

32 +12V output (link to terminal 11) N/A

33 0 Volt for DCP and timers (link to terminal 9) N/A

34 TSO timer input (optional link to terminal 33 0V) PL1/S




Terminal no.


35 AWS brake delay timer (optional link to terminal 33 0V) SK1/a

36

37

38 OSS timer input (optional link to terminal 33 0V) PL1/F

39 Vigilance reset output SK1/T

40 Vigilance reset output SK1/U

41 TDR output AWS clear received SK1/b

42 TDR output AWS clear received SK1/c

43 TDR output AWS caution received SK1/d

44 TDR output AWS caution received SK1/e

45 TDR output AWS indicator to all black SK1/f

46 TDR output AWS indicator to all black SK1/m

47 TDR output AWS indicator to yellow/black SK1/j

48 TDR output AWS indicator to yellow/black SK1/k

49 TDR output wrong direction loop detected PL1/h

50 TDR output wrong direction loop detected PL1/j

51 TDR output correct direction loop detected PL1/k

52 TDR output correct direction loop detected PL1/m

53 TDR output TSO activated PL1/n

54 TDR output TSO activated PL1/p

55 TDR output TI/fault indicator enabled PL1/r

56 TDR output TI/fault indicator enabled PL1/s

57 TDR output TPWS acknowledge button pressed SK1/g

58 TDR output TPWS acknowledge button pressed SK1/h

59 TDR output TPWS isolated SK1/r

60 TDR output TPWS isolated SK1/s

61 TDR output brake demand request SK1/n

62 TDR output brake demand request SK1/p




Terminal no.


1 AWS bell output SK1/X

2 North input from AWS receiver SK1/N

3 South input from AWS receiver SK1/M

4

5

6 40 volt power supply 0V SK1/J

7 40 volt power supply +40V SK1/R

8

9 12 volt power supply 0V (link to terminal 33) SK1/K

10

11 12 volt power supply +12V (link to terminal 32) SK1/L

12 AWS horn output SK1/Z

13 AWS indicator to all black SK1/W

14 AWS indicator to yellow/black SK1/V

15 AWS reset pushbutton input SK1/F

16

17 Brake output relay SK1/A

18 Brake output relay SK1/C

19 Not fitted

20 Not fitted

21 Not fitted

22 Not fitted

23 Not fitted

24 Not fitted

25 Not fitted

26 Not fitted

27 Not fitted

28 Not fitted

29 Not fitted

30 Not fitted

31 Not fitted

32 Not fitted

33 0 volt for DCP and timers (link to terminal 9) N/A

34 Not fitted




Terminal no.


35 AWS brake delay timer (optional link to terminal 33 0V) SK1/a

36 Not fitted

37 Not fitted

38 Not fitted

39 Vigilance reset output SK1/T

40 Vigilance reset output SK1/U

41 TDR output AWS clear received SK1/b

42 TDR output AWS clear received SK1/c

43 TDR output AWS caution received SK1/d

44 TDR output AWS caution received SK1/e

45 TDR output AWS indicator to all black SK1/f

46 TDR output AWS indicator to all black SK1/m

47 TDR output AWS indicator to yellow/black SK1/j

48 TDR output AWS indicator to yellow/black SK1/k

49 Not fitted

50 Not fitted

51 Not fitted

52 Not fitted

53 Not fitted

54 Not fitted

55 Not fitted

56 Not fitted

57 TDR output AWS reset pushbutton pressed SK1/g

58 TDR output AWS reset pushbutton pressed SK1/h

59 TDR output TPWS isolated SK1/r

60 TDR output TPWS isolated SK1/s

61 TDR output brake demand request SK1/n

62 TDR output brake demand request SK1/p




Terminal reference

Function Electrical interface specification

A TSO indicator input 6 – volts dc at 45mA

B Brake demand indicator input 6 – volts dc at 45mA

C Temporary isolation indicator input 6 – volts dc at 45mA

D Return for all indicators Power supply zero volts

E TSO switch output 12 – volt output 100mA max.

F TSO switch input Power supply 12 - volts

G Not used

DCP connector reference


1 TSO indicator input 6 – volts dc at 45mA

2 Brake demand indicator input 6 – volts dc at 45mA

3 Temporary isolation indicator input 6 – volts dc at 45mA

4 Return for all indicators Power supply zero volts

5 TSO switch output 12 – volt output 100mA max.

6 TSO switch input Power supply 12 - volts

DCP terminal reference







6 TSO switch input Power supply 12 - volts




DCP terminal reference







6 TSO switch input Power supply 12 – volts

7 Power up indicator 12 – volts dc at 45mA

8 TPWS acknowledge switch 40 – volts dc at 100mA

TIS connector reference


13 Temporary isolation isolate output 12 – volt at 100mA max.

14 +12 volt isolate switch input 12 – volt supply 100mA max.

23 Temporary isolation normal output 12 – volts at 100mA max.

24 +12 volt normal switch input 12 – volt supply 100mA max.

Isolation unit terminal


1 Vehicle battery supply 110 – volts 5 amps maximum

2 Vehicle system supply 110 – volts 1 amp maximum

3 Output to voltage converter 110 – volts 1 amp maximum

4 Output to brake equipment 110 – volts 5 amps maximum

5 Vehicle 0-volts 6 amps maximum.

6 Temporary isolation switch common 12 – volts 100mA max.

7 Temporary isolation switch (isolate) 12 – volts 100mA max.

8 Temporary isolation switch (normal) 12 – volts 100mA max.




Connector reference

Function Terminal no.

A Received aerial signal +ve 1

B Received aerial signal -ve 2

C Cable screen Grounded

D Aerial test signal +ve 4

E Aerial test signal -ve 5

F Cable screen Grounded

Connector reference

Cable description Function Connector reference

A Cable 1, core 1 Received aerial signal +ve A

B Cable 1, core 2 Received aerial signal -ve B

C Cable 1 screen Cable screen C

D Cable 2, core 1 Aerial test signal +ve D

E Cable 2, core 2 Aerial test signal -ve E

F Cable 2 screen Cable screen F

Terminal no.

Function Destination

1 Reverse input Vehicle direction selector

2 Forward input Vehicle direction selector

3 +12 volt supply input Junction box terminal 11

4 0-volt supply input Junction box terminal 9

5 Locomotive aerial input +ve Aerial junction box terminal 1

6 Locomotive aerial input –ve Aerial junction box terminal 2

7 Tender aerial input +ve Aerial junction box terminal 1

8 Tender aerial input -ve Aerial junction box terminal 2

9 Aerial test +ve to tender Aerial junction box terminal 4

10 Aerial test +ve to locomotive Aerial junction box terminal 4

11 Aerial test –ve common Common terminal

12 Aerial test +ve to control unit Junction box terminal 22




Terminal no.


1 12- volt supply input (+ve) Junction box terminal 11

2 12- volt supply output (+ve) Alarm and indicator unit (end 2) pin B

3 12- volt supply output (+ve) DCP (end 2) pin 6

4 12- volt supply output (+ve) Alarm and indicator unit (end 1) pin B

5 12- volt supply output (+ve) DCP (end 1) pin 6

6 12- volt supply output (-ve) DCP (end 2) pin 4

7 12- volt supply output (-ve) DCP (end 1) pin 4

8 12- volt supply input (-ve) Junction box terminal 9

9 AWS acknowledge input (end 2) ACK P/B terminal 1

10 AWS acknowledge input (end 1) ACK P/B terminal 1

11 AWS acknowledge output Junction box terminal 15

12 Aerial +ve input (end 2) TPWS aerial pin 2

13 Aerial +ve input (end 1) TPWS aerial pin 2

14 Aerial +ve output Junction box terminal 20

15 Aerial -ve input (end 2) TPWS aerial pin 5

16 Aerial -ve input (end 1) TPWS aerial pin 5

17 Aerial -ve output Junction box terminal 21

18 Aerial test +ve input (end 2) TPWS aerial pin 3

19 Aerial test +ve input (end 1) TPWS aerial pin 3

20 Aerial test +ve output Junction box terminal 22

21 OSS timer bit 0 output Junction box terminal 38

22 Overspeed sensor timer bit 0 (freight vehicle link) (if required)

Link to 23 (if required)

23 Link to 22 (if required)

24 Overspeed sensor timer bit 0 (passenger vehicle link) (if required)

Link to 25 (if required)


26 Passenger/freight input 110-volts Pass/freight switch

27 Spare output 1

28 Input for spare output 1 Link to 29 (if required)





Terminal no.








36 Spare output 2

37 Vehicle end select input 12-volts Change end switch

38 110-volt input supply negative Vehicle 110-volt supply

39 Spare – available for cab 1 select

40 Test aerial negative TPWS aerial and control unit junction box




Appendix G Optimum overhaul periodicities for AWS/TPWS equipment

The following two tables detail the optimum overhaul periodicities for AWS and TPWS equipment. The tables represent those components that are being tracked by the ATOC component tracking application and those that are not but are included for completeness. This appendix is sourced from ATOC Code of Practice ACOP/EC/01001. Table G1: Recommended overhaul periodicity for AWS/TPWS components that ARE being tracked by the ATOC component tracking application.

Description Component type code

Catalogue no./OEM part no.

Recommended overhaul periodicity

Standard reed receivers

RR 062/010222 (Unipart Rail) 062/010223 (Unipart Rail) 062/010224 (Unipart Rail) 062/010225 (Unipart Rail) 062/010226 (Unipart Rail) 062/010227 (Unipart Rail) 062/010228 (Unipart Rail) 062/500000 (Howells) 062/500001 (Howells) 062/500002 (Howells) 062/500003 (Howells) 062/500004 (Howells) 062/500005 (Howells) 062/500056 (Howells) 062/500057 (Howells) 062/500059 (Howells) 062/500061 (Howells) 062/500062 (Howells) 062/500063 (Howells) 062/500065 (Railpart) 062/500066 (Unipart Rail) 062/500067 (Howells) 062/500068 (Howells) 062/500069 (Howells) 062/500070 (Howells) 104044 (Thales)

C4

Solid state receivers

RS 062/010002 (Unipart Rail) 062/010003 (Unipart Rail) 062/010006 (Unipart Rail) 062/010007 (Unipart Rail) 062/010008 (Unipart Rail) 062/010009 (Unipart Rail) 062/010010 (Unipart Rail) 062/010011 (Unipart Rail)

Renew on failure or after visible detection of damage/ deterioration of receiver or cable







Solid state receivers

RS 062/010012 (Unipart Rail) 062/010013 (Unipart Rail) 062/010014 (Unipart Rail) 062/010015 (Unipart Rail) 062/010016 (Unipart Rail) 062/010017 (Unipart Rail) 062/010018 (Unipart Rail) 062/010020 (Unipart Rail) 062/010021 (Unipart Rail) 062/010022 (Unipart Rail) 062/010024 (Unipart Rail) 062/010025 (Unipart Rail) 062/010026 (Unipart Rail) 062/010028 (Unipart Rail) 062/010029 (Unipart Rail) 062/010030 (Unipart Rail) 062/010031 (Unipart Rail) 062/010032 (Unipart Rail) 608901-XX (Thales) 608902-XX (Thales) 608904-XX (Thales)

Renew on failure or after visible detection of damage/ deterioration of receiver or cable

Indicator IN 062/006580 (Unipart Rail) 062/006610 (Unipart Rail) 062/500028 (Howells) 062/500029 (Howells)

C4

Alarm and indicator unit

IU 098/006925 (Howells) 098/007628 (STS) 062/500042 (Howells) 062/500043 (Howells) 062/000100 (Unipart Rail) 334/030100 (STS) 062/006601 (Unipart Rail) 062/014454 (Unipart Rail)

C4*

* It may be more appropriate to maintain the alarm and indicator unit at C6 given the expected level of reliability. However, it may be more practicable to carry out its renewal at C4 when items in a similar location will be renewed.





Catalogue no./OEM part no. Recommended overhaul periodicity

Solid state alarm and indicator unit

IS 062/014454 (Unipart Rail) Renew on failure

Combined receiver module

RM 632186-01 (Thales) 632186-02 (Thales) 632357-XX (Thales)

Overhaul policy not determined at time of publication

TPWS control unit CU 098/017819 (Thales) 098/016430 (Thales) 062/014440 (Unipart Rail)

Renew on failure

TPWS PSU PS 098/016429 (Thales) 015/011902 (Thales) 062/014453 (Unipart Rail)

Renew on failure

Control panel CP 098/016410 (Thales) 098/016498 (Thales) 064/007231 (Thales) 015/010957 (Thales) 608450-03 (Thales) 608450-00 (Thales) 062/014457 (Unipart Rail) 062/014458 (Unipart Rail) 062/015941 (Unipart Rail) 062/015995 (Unipart Rail)

Overhaul periodicity not determined at time of publication

Temporary isolation switch

TI 098/016412 (Thales) 062/014443 (Unipart Rail) 062/015989 (Unipart Rail)

Overhaul periodicity to be determined

TPWS aerial AN 062/014444 (Unipart Rail) 090/014241 (Thales) 098/016413 (Thales) 098/017888 (Thales) 098/017897 (Thales) 098/017898 (Thales) 098/017899 (Thales) 098/017900 (Thales) 098/017901 (Thales) 604428-02 (Thales)

Overhaul periodicity to be determined







Dual cab switching PEC

DS 090/014865 (Thales) 062/015137 (Thales) 608121-01 (Thales) 608121-11 (Thales) 062/014451 (Unipart Rail) 062/015983 (Unipart Rail)

Renew on failure

Table G1

Table G2: Components that ARE NOT being tracked by the ATOC component tracking application.

Description Catalogue no./OEM part no.


AWS/TPWS lightweight receiver 015/011837 (STS) Overhaul periodicity to be determined

Relay unit (removed with TPWS)

062/014607 (Unipart Rail) 062/014612 (Unipart Rail) 062/500006 (Howells) 062/500038 (Howells)

C4

EP repeat relay unit (removed with TPWS)

062/014609 (Unipart Rail) 062/014611 (Unipart Rail) 062/500036 (Howells) 062/500037 (Howells)

C4

Brake and horn relay unit (removed with TPWS)

062/014603 (Unipart Rail) 062/500007 (Howells)

C4

EP valve 062/014602 (Unipart Rail) 062/014733 (Unipart Rail) 062/014737 (Unipart Rail) 062/500035 (Howells) 062/500040 (Howells) 062/500041 (Howells)

C4

Bell 062/000280 (Unipart Rail) 062/500015 (Howells)

C4

Voltage converters (removed with TPWS)

062/014620 (Unipart Rail) 062/014623 (Unipart Rail) 062/014624 (Unipart Rail) 062/014626 (Unipart Rail) 062/014627 (Unipart Rail) 062/500008 (Howells) 062/500009 (Howells) 062/500010 (Howells) 062/500011 (Howells) 062/500012 (Howells)

Renew on failure




Description Catalogue no./OEM part no.


AWS reset pushbutton 062/014171 (Unipart Rail) 062/500031 (Howells) C4

AWS isolating switch 062/014177 (Unipart Rail) 062/500034 (Howells) Renew on failure

Change end switch 062/014173 (Unipart Rail) 062/014074 (Unipart Rail) 062/500032 (Howells) 062/500033 (Howells)

Renew on failure

Vacuum horn (removed with TPWS)

062/006106 (Unipart Rail) 062/500027 (Howells) Renew on failure

Air horn (removed with TPWS) 070/020843 (Unipart Rail) 062/500044 (Howells) Renew on failure

Relay unit junction box (removed with TPWS)

062/000739 (Unipart Rail) 062/000741 (Unipart Rail) 062/500016 (Howells)

Renew on failure

Receiver junction box 062/000744 (Unipart Rail) 062/500017 (Howells) Renew on failure

Cable: 30" LH Entry 30" RH Entry 30" Top Entry 48" Top Entry 2.8m RH Entry 72" RH Entry 48" LH Entry 48" RH Entry 72" LH Entry

062/001360 (Unipart Rail) 062/001361 (Unipart Rail) 062/001362 (Unipart Rail) 062/001363 (Unipart Rail) 062/001364 (Unipart Rail) 062/001365 (Unipart Rail) 062/001368 (Unipart Rail) 062/001369 (Unipart Rail) 062/001375 (Unipart Rail)

C4

Cable: 30" LH Entry 30" RH Entry 30" Top Entry 48" Top Entry 2.8m RH Entry 72" RH Entry 48" LH Entry 48" RH Entry 72" LH Entry

062/500018 (Howells) 062/500019 (Howells) 062/500020 (Howells) 062/500021 (Howells) 062/500022 (Howells) 062/500023 (Howells) 062/500024 (Howells) 062/500025 (Howells) 062/500026 (Howells)

C4

New pushbutton 098/017166 (Thales) C4

Mark II terminal box 098/016425 (Thales) 098/016816 (Thales) Renew on failure

Mark III terminal box 072/009710 (Thales) Renew on failure TPWS aerial harness Various (Thales) Overhaul periodicity to be

determined TPWS aerial terminal box 098/016420 (Thales) Renew on failure

Table G2




Appendix H Form RT3185 reporting of AWS failure or irregularity







Appendix I Form RT3188 activation of TPWS




Appendix J Component tracking application form




Appendix K Component tracking information sheet AWS/TPWS component tracking information

Vehicle no: (Not unit number!)

British Rail Catalogue no.

Equipment description Serial no. out Serial no. in

Date

Originating depot

Receiver height

Defect reference

(to be measured on the vehicle for example Trust Incident No.)

Defect code Please tick (Please see Thales fault guide card)

1 (Horn and bell)

2 (Horn instead of bell)

3 (No indication instead of bell)

4 (Bell and horn)

5 (Wrong side failure bell instead of horn)

6 (Brake without horn)

7 (Wrong side failure no horn or brake)

7a (Wrong side failure sunflower not yellow/black)

8 (Horn instead of indication)

9 (Bell instead of indication)

10 (Unable to cancel)

11 (Sunflower not all black)

16 (TPWS failed to activate)

16a * (TPWS failed in overspeed)

17 (Unrequired TPWS activation)

17a * (Spurious brake application)

0 * (Other defect not defined)

Findings on test at depot: (Did you use the AWS test equipment?)

Fault diagnosed by depot: (What do you think is wrong?)

Action taken by depot: (What did you do with the part?)

* It should be noted that fault codes 16a, 17a and 0 are codes only used for the component tracker application and will not be found in any other AWS/TPWS documentation.




Appendix L Typical locomotive fault diagnosis procedure The following fault finding charts have been provided by English Welsh and Scottish Railway (EWS) and generally reflects locomotive installations with either Thales or Unipart Rail combined AWS/TPWS electronic control units. The following table covers faults that may arise during the power up test.

Fault description Fault diagnosis and additional tests

Complete power up self-test failure (both cabs on a dual-cab locomotive) • No indications from TPWS cab

control panel. • No indications from AWS

indicator, no audible caution tone.

Probable causes: loss of input supply to voltage converter; internal failure of voltage converter; loss of 12V supply to AWS/TPWS terminal box; or internal failure of AWS/TPWS control unit. Additional tests: (DMM set to 0-200V dc range) • Vehicle control voltage is present at the voltage

converter inputs. No voltage, check for circuit continuity to supply source (refer to vehicle schematics); (note on Class 66 locomotives there have been problems with the cab direction controller ‘stick’ micro-switch failing to operate, this micro-switch operates the ‘CRR’ relays.

• Voltage converter output voltages are correct, replace if voltages are outside of specified range.

• 12V supply is present between the AWS terminal box terminals 11 (+12V) and 9 (-12V). If no 12V supply check for circuit continuity to voltage converter (refer to vehicle schematics). If 12V supply present, change control unit if fault is still present.

Complete power up self-test failure (one cab only on a dual-cab locomotive) • Power up test cannot be

performed at no. 2 end cab (no. 1 end Class 66 and 67).

• Power up test correctly performed at no.1 end cab (no. 2 end Class 66 and 67).

Probable causes: defective change end relay; defective change end card; loss of supply to change end relay; or loss of 12V supply to change end card. Additional tests: (DMM set to 0-200V dc range) • Change end relay picks up when cab no. 2 is activated

(no. 1 cab Class 66 and 67). Relay fails to operate, check for locomotive control voltage across relay coil terminals, replace relay if defective.

• Change end switching card, 12V should be detected between ‘Faston’ terminals T37 and T6 on the change end card only when no. 2 cab is active (no. 1 on Class 66 and 67). No voltage when cab is active, check continuity of 12V supply from the change end relay. If 12V supply present, check switching card relays operate by removing/reconnecting wire from T37 (operation is an audible check). Replace defective change end card.





Partial power up self-test failure (AWS indicator fails to set to ‘all black’). • AWS indicator fails to set to

‘all black’. • All 3 TPWS control panel

indicator lamps illuminated. • No audible AWS caution

indication. • No response to AWS reset

pushbutton.

Probable causes: defective AWS receiver, receiver wiring connections; defective AWS indicator, wiring connections; defective AWS/TPWS control unit; earth fault on 12V supply; defective change end switching card. Additional tests: (DMM set to 0-200V dc range, high voltage tester set to 250V, Unipart Rail test box fitted) • Check continuity of AWS receiver wiring and security of

terminations from the AWS/TPWS terminal box to the AWS receiver junction box. Check the AWS receiver harness for condition and correct insertion of connector. Repair any defects and/or replace harness.

• Temporarily connect a new AWS receiver and commission a new power up test. Power up test is now successful, renew old AWS receiver. Power up test is not successful, reconnect old AWS receiver.

• Check AWS indicator (‘all black’) and continuity of wiring using Unipart Rail test box. Indicator fails to respond, replace indicator/alarm and indicator unit (where a change end card is used check switching card continuity T38 to T42 or T43, 12V should be detected at AWS/TPWS terminal box terminal 8, replace switching card if defective.

• Temporarily connect a new AWS/TPWS control unit and commission a new power up test. Power up test is now successful, renew old control unit. Power up test is not successful reconnect old control unit.

• Disconnect AWS/TPWS control unit and Unipart Rail test box and check for earth faults using a high voltage tester.

Partial power up self-test failure (AWS audible caution indication – horn - will not cancel). • AWS indicator set to ‘all

black’. • All 3 TPWS control panel

indicator lamps illuminated. • Audible AWS caution

indication sounds continuously.

• No response to AWS reset pushbutton.

Probable causes: defective AWS reset pushbutton; earth fault on 40V supply; defective AWS/TPWS control unit; defective AWS receiver; defective alarm/alarm and indicator unit; defective change end switching card. Additional Tests: (DMM set to 0-200V dc range, high voltage tester set to 250V, Unipart Rail test box fitted). • Check 40V supply is present at the reset pushbutton. No

40V supply, check continuity of 40V supply from the reset pushbutton to AWS/TPWS terminal box terminal 7. 40V supply present check reset pushbutton operation.

• Check 40V supply remains within range (35V to 80V) when AWS reset pushbutton is pressed. Voltage below 35V check for earth faults using a high voltage tester.





• AWS indicator does not set to ‘black and yellow’.

• AWS indicator set to ‘all black’. • Three TPWS control panel

indicator lamps illuminated. • AWS audible caution indication

sounds continuously. • No response to AWS reset

pushbutton. • Power up test completes when

AWS reset pushbutton pressed.

• Check 40V supply is retained on AWS/TPWS terminal box terminal 15 after AWS reset pushbutton is pressed. No 40V supply change AWS/TPWS control unit.

• Check AWS indicator (‘black and yellow’) and continuity of wiring using Unipart Rail test box. Indicator fails to respond, replace indicator/alarm and indicator unit; check switching card (where fitted) continuity T39 to T40 or T41 and 12V should be detected at AWS/TPWS terminal box terminal 16, replace switching card if defective.

• Check continuity of AWS receiver wiring and security of terminations from the AWS/TPWS terminal box to the AWS receiver junction box. Check the AWS receiver harness for condition and correct insertion of connectors. Repair any defects and/or replace the harness.

• Temporarily connect a new AWS receiver and commission a new power up test. Power up test is now successful, renew old AWS receiver. Power up test is not successful, reconnect old AWS receiver.

Partial power up self-test failure (AWS audible caution indication does not sound). • AWS indicator set to ‘all black’. • All 3 TPWS control panel

indicator lamps illuminated. • Audible AWS caution indication

does not sound. • Power up test completes when

AWS reset pushbutton pressed and released.

Probable causes: defective AWS horn/alarm and indicator unit/Yodalarm; horn wiring 12V supply; defective cab repeat relay. Additional Tests: (DMM set to 0-200V dc range) • Check AWS horn and continuity of wiring using Unipart

Rail test box. Horn fails to sound, check 12V supply is present at terminal box terminal 12.

• 12V supply present at terminal 12. Check 12V present between alarm indicator pins V and C in harness, Yodalarm +ve to –ve terminals, replace alarm and indicator Unit/Yodalarm if 12V is present.

• No 12V supply present across alarm units. Check wiring continuity from terminal box (note on alarm and indicator units fitted to dual-cab locomotives the 12V horn supply is switched to the active cab (for example by the CRR relays on the Class 66 locomotive). Classes 66 and 67 have a no. of connection points in the circuit which should also be inspected.

Partial power up self-test failure (temporary isolation/fault lamp flashes at end of test). • AWS indicator set to ‘all black’. • All 3 TPWS control panel

indicator lamps illuminated. • Audible AWS caution indication

sounds continuously.

Probable causes: defective TPWS aerial, loose or broken wiring connections from aerial to AWS/TPWS terminal box; defective change end switching card (where fitted). Note this fault will occur in service if a power-up test is carried out with the TPWS aerial positioned over an active TPWS loop. Additional Tests: (DMM set to 20kΩ range). • Disconnect the TPWS aerial (both ends on a dual-cab

locomotive) and check for damage and dirt ingress at the pins and mating harness socket. Replace the aerial/harness if damages, for dirt ingress flush with WD40 and dry with a paper towel. Note the aerial to harness connector should be finger/hand tight and nipped up with pipe grips to ensure a good connection. Over-tightening of the connector will cause damage to the aerial or plug.





• Audible indication cancels with AWS reset pushbutton.

• Indicator sets to ‘black and yellow’.

• Brake demand and TSO indicators are extinguished.

• Temporary isolation/fault indicator flashes.

• Check the aerial for continuity between pins 2 and 5 (110-130Ω typical) and between pins 3 and 4 (15-21Ω typical). Replace aerial if an open circuit is found or the DMM reading falls outside the typical range.

• With the aerials connected check for circuit continuity at the AWS/TPWS terminal box as follows: terminals 20 to 21 (aerial) and 22 to 23 (aerial test), disconnect the no. 1 end aerial (dual-cab locomotives) and re-test with no. 2 cab open. Check terminal box to aerial wiring for damage or loose connections and operation of the change end switching card (where fitted – see below) if an open circuit is found.

• On dual-cab locomotives, check for correct operation of the change end switching card, T14 to T13 n/c / T12 n/o, T17 to T16 n/c / T15 n/o and (T20 to T19 n/c /T18 n/o. Note the n/c contact is made with no. 1 cab open and the n/o contact is made with the no. 2 cab open. Replace switching card if found to be defective.

Partial power up self-test failure (control panel lamps fail to illuminate). • AWS indicator set to ‘all

black’. • One or more TPWS control

panel indicator lamps fail to illuminate.

• Audible AWS caution indication sounds continuously.

• Audible AWS caution indication cancels with AWS reset pushbutton.

• Indicator sets to ‘black and yellow’.

• Lit indicators are extinguished.

Probable causes: defective TPWS control panel, loose or broken wiring connections from AWS/TPWS terminal box to control panel. Additional tests: • Check terminal box to control panel wiring for damage or

loose connections. • Check continuity between AWS/TPWS terminal box

terminals and change end switching card as follows: no. 1 end (27 to T7, 28 to T7 and 29 to T7), no. 2 end (27 to T6, 28 to T6 and 29 to T6). Replace cab control panel if defective.




Appendix M AWS testing using a hand-held permanent magnet The AWS hand-held test magnet can be used to check the functioning of the AWS trainborne sub-system to detect where, within the basic sequence of events, a fault occurs. Testing the AWS trainborne sub-system with a hand-held test magnet has the advantage of rapidly repeating the failure. Dual-cab vehicles should be tested from both ends, as failure at one end only will indicate that the control unit, PSU and AWS receiver are healthy. MA - Test after a 'right side failure’ reported MA1 Before any equipment or connections are disturbed, perform the tests described in items

MA2 to MA8.

MA2 With the air system fully charged, energise the AWS in the cab in which the failure is reported to have occurred.

MA3 Check that the horn sounds. Press and release the 'AWS acknowledge' pushbutton to silence the horn.

MA4 Carry out a caution signal test cancelling the AWS as follows: • simulate a caution indication by passing the south pole (blue) end of the magnet

under the AWS receiver • the indicator should change to or remain 'all black', and after 1 second the horn

should sound • within 2 seconds, press and release the 'AWS acknowledge' pushbutton to silence

the horn - the indicator should change to 'yellow and black' and there should be no brake application

MA5 Carry out a caution signal test allowing a full brake application and then cancelling the AWS, as follows: • simulate a caution indication by passing the south pole (blue) end of the magnet

under the AWS receiver • the indicator should change to or remain 'all black', the horn should sound after

1 second and, after a further time delay (2.0 seconds or 2.7 seconds) appropriate to the vehicle concerned, a full brake application should occur

• press and release the 'AWS acknowledge' pushbutton -the horn should be silenced and the indicator should change to 'yellow and black' - after a time delay appropriate to the vehicle concerned, the brake should release at least 59 seconds after the brake application

MA6 Carry out a caution signal test allowing a partial brake application and then cancelling the AWS, as follows: • simulate a caution indication by passing the south pole (blue) end of the magnet

under the AWS receiver • the horn should sound after 1 second. As soon as the brake starts to apply, press

and release the 'AWS acknowledge' pushbutton to silence the horn - the brake should continue to apply and should not release until after a time delay appropriate to the vehicle concerned

MA7 Carry out a clear signal test as follows: • simulate a clear indication by passing the south pole (blue) end of the magnet under

the AWS receiver and then passing the north pole (red) end of the magnet, taking less than 1 second between the two operations

• the indicator should change to 'all black’ and the bell ring for approximately 0.5 seconds (or a single chime is emitted on vehicles fitted with an alarm and indicator unit)




MA8 Carry out a test with the AWS equipment isolated, as follows:

• isolate the AWS in the cab concerned • operate the AWS receiver with the south pole (blue) end and then the north pole

(red) end of the magnet, taking less than 1 second between the two operations - follow this by operating the AWS receiver with the south pole (blue) end only - there should be no effect on the AWS equipment

• de-isolate the AWS in the cab concerned

MA9 If any item of AWS equipment is suspected of being faulty it must be changed. After the replacement has been fitted repeat items MA4 to MA8 three times. If either: • the reported fault can be reproduced, but changing the item indicated during the

above tests does not cure it, or • the fault cannot be reproduced but the vehicle has a history of related faults Check the system using an AWS test unit, if available, then visually examine the wiring and connectors as far as possible. If the fault is still not revealed then detailed wiring tests must be carried out.

MA10 After any equipment change, wiring repair or renewal has been carried out then items MA4 to MA8 should be repeated.

MB - Test after a 'wrong side failure’ reported The AWS hand-held test magnet can be used to check the functioning of the AWS trainborne sub-system as part of a wrong side failure investigation before any equipment/connections are disturbed. This should be as part of an overall inspection and test procedure using more sophisticated AWS test equipment. MB1 Carry out items MA2 to MA8, repeating items MA4 to MA8 a total of three times.

MB2 If any item of AWS equipment is suspected of being faulty it must be changed. If the AWS operates correctly or does not reproduce the reported fault, then follow procedures for full system test. After replacements have been fitted, items MA2 to MA8 should be repeated. If either: • the reported fault can be reproduced, but changing the item indicated during the

above tests does not cure it, or • the fault cannot be reproduced but the vehicle has a history of related faults Check the system using an AWS test unit, then visually examine the wiring and connectors as far as possible. If the fault is still not revealed then detailed wiring tests must be carried out.

MB3 After any equipment change, wiring repair or renewal has been carried out, then items MA4 to MA8 should be repeated.




Appendix N AWS testing using STS TY287 tester The following pages reproduce the STS TY287 AWS fault tester operating manual (V1 Draft7). Users should consult the manufacturer for any later issues of this instruction manual.

AWS fault tester

TY287

Instruction manual

Draft 7




Contents Purpose

Scope

Introduction

Description of parts

a) Flux generator

b) Equipment case

c) Handset

d) Power cable

e) Handset cable

f) Battery charger

g) Testing equipment maintenance

Operation of the equipment

a) Setting of magnet type

b) Setting of flux polarity

c) Setting of power level

d) Setting of simulated train speed

e) Conducting the test

Interpretation of results

a) Test failure

b) System confirmation

c) Depot maintenance obligations

d) Suspected wrong side failure

e) Class benchmarking

Fore and aft positions for various AWS receiver designs

Specification

Example of AWS receiver sensitivity table

Description of fault codes

Illustration of parts and connection details




Purpose The purpose of the AWS fault test equipment is to test AWS receivers in situ. It can identify the sensitivity of the receiver and also confirm its correct operation.

The tester also supports repeatable testing in a controlled manner.

Scope The AWS fault tester can be used either as a diagnostic tool to establish faults or as a means of confirming the sensitivity of fitted receivers.

It must be recognized that the AWS system does have tolerance from both an infrastructure and train borne perspective, with the trackside equipment generally providing higher fields than the minimum required by the specification or simulated by the AWS fault tester. Therefore, under normal circumstances, the trainborne equipment could be less sensitive and still appear to operate.

Under normal circumstances the AWS fault tester would be used for investigating reported AWS receiver faults. It may be used as a maintenance tool but this is at the discretion of the maintenance authority.

The AWS fault tester should be used in accordance with this instruction manual.

Note: users shall ensure the AWS fault tester shall not compromise, or be used as a substitute for, current maintenance and defect repair practices.

Introduction The AWS receiver depot test unit has been designed to provide a means of simulating the effect of an AWS receiver passing over AWS track equipment. The test unit enables the depot engineer to simulate a number of practical situations encountered on the track.

The equipment consists of the following parts:

a) flux generator

b) equipment case to provide the power for the flux generator

c) handset on which various tests can be set

d) power cables to connect items a) and b)

e) handset cable to connect items b) and c)

f) battery charger

g) testing equipment maintenance.

The test unit must only be used with the power cable provided. The power cable must not be modified in any way.

WARNING: the operator shall comply with local depot instructions and observe ac and dc 3rd rail electrification requirements at all times.

Description of parts a) Flux generator

The flux generator comprises of an air-cored inductor mounted on a lightweight framework with detachable handle for positioning the inductor in the correct position for testing AWS receivers.




b) Equipment case The equipment case is powered by an internal chargeable sealed lead acid battery. It also contains the electronics which generates the appropriate flux to the flux generator. T he range of signals which can be produced is pre-coded into the control program but the user can select a particular test using the associated handset.

The battery capacity is sufficiently large to provide several days use without charging. The number and type of tests conducted determines the rate at which the batteries are drained.

The equipment case is connected to the flux generator unit by a power cable as described in section d) below and to the handset by a handset cable as described in section e) below.

To charge the battery, the power cable must be removed and the Battery Charger fitted to this same connector.

c) Handset This is a hand-held unit provided with an LED alphanumeric display and control pushbuttons.

The display gives the user simple prompts to allow the required test to be easily selected by the pushbuttons.

The handset is connected to the equipment case by a handset cable as described in section e) below.

The programming options are described in section O.5 below.

d) Power cable The cable connects the flux generator to the equipment case and is terminated by bayonet connectors at either end. It is important that the power cable is not modified in any way, as this will invalidate the testing.

e) Handset cable The standard cable is 10 metres in length and terminated in an XLS connector with locking latch at either end. If required the connection can be extended to 20 metres by use of a second cable.

f) Battery charger This is a freestanding charger, which is connected, via an integral lead, to the flux generator/charger connection.

The status of the charging process is revealed by a three-state indicator. Initially a red LED is displayed indicating a low level of charge to protect the cells. After this stage the LED displays a yellow aspect indicating bulk charge is taking place. Finally the LED displays a green aspect to indicate that charging is complete.

g) Testing equipment maintenance TBD.

Operation of the equipment Before operating the equipment for the first time ensure that the internal battery is fully charged. Connect the equipment as shown in Annex P.




The flux generator has to be accurately positioned beneath the vehicle to be tested. The framework must be located on the running rails with the flux generator on the centre line of the track to ensure the correct lateral and vertical position. The framework has two locating points that when correctly positioned sit within the rails. It must then be aligned fore-and-aft so as to place the centre of the flux field directly underneath the AWS receiver being tested. The correct fore and aft positions for various AWS receiver designs are detailed in Annex P. The flux generator is connected to the equipment case by a power cable terminated in a bayonet connector at either end.

Position the flux generator beneath the AWS receiver fitted to the vehicle according to the AWS receiver type fitted as shown in Annex P1.

The on/off switch is located on the panel inside the equipment case. When switched on a start-up message is displayed for approximately 2 seconds, the display will then show the default test setting.

S t a n d a R d S - N

1 0 0 %

1 2 5 m p h

The four sections of the display show the four parameters that can be changed to enable the tester to carry out a test.

Parameters may be changed by pressing the ‘select’ pushbutton to select the parameter to be changed. The selected section of the display will flash to show that it can be changed. Repeatedly pressing the ‘select’ pushbutton will scroll through the setting options. The ‘∧’ and ‘∨’ pushbuttons can then be used to select the required value.

a) Setting of magnet type Two settings are available: standard strength and extra strength (most dc electrified lines). The default setting is standard strength.

b) Setting of flux polarity and sequence Depending on the polarity of the dc current through the flux generator either an AWS permanent magnet ‘south’ or electromagnet ‘north’ is simulated. To select a test sequence, scroll down the list which after completion will return to the first item. The screen display and a description of the tests are listed below:

Display indication Test set Simulated condition

S-N South followed by north polarity Clear

S South polarity AWS warning

N North polarity No valid simulated condition

N-S North followed by south polarity AWS warning (reverse direction running on unsuppressed magnets)

N-S-N North followed by south then by north polarity

Clear

The default setting is south followed by north polarity.




c) Setting of power level When setting up the test it is possible to adjust the energy transmitted into the coil. The following power levels are available and can be set by scrolling down the list. The values simulate the percentage of flux required to meet the Railway Group Standard (GE/RT8035) minimum at the specified height for the selected magnet type (standard or extra strength).

Standard strength magnets (ac and non electrified lines)

Power level Flux density

50% of full power 1.50mT ‘Shall not detect’

70% of full power 2.17mT



100% of full power 3.10mT ‘Shall detect’







The minimum ‘pass’ criteria for power level and flux density is indicated in bold

Extra strength magnets (most dc electrified lines)

Power level Flux density

70% of full power 3.5mT ‘Shall not detect’







The minimum ‘pass’ criteria for power level and flux density is indicated in bold

d) Setting of simulated train speed The train speed is selected by scrolling up and down the list and should be set to the level equal or greater than the maximum speed of the vehicle under test. The following tests are available.




Standard strength Extra strength

20 mph 20 mph

40 mph 40 mph

60 mph 60 mph

80 mph 80 mph

90 mph 90 mph

100 mph 100 mph

110 mph Not available

125 mph Not available

e) Conducting the test When the test has been set to the operator’s requirement, pressing the ‘test’ pushbutton will execute the test. When the test has been successfully completed the message ‘test completed’ will be displayed. After 2 seconds the display reverts to the current test setting. It is possible to execute a test by pressing the ‘test’ pushbutton at any time, even when part of the display is flashing.

See Annex Q.5 for an example of an AWS receiver sensitivity table.

If the equipment is unable to complete the test, the display will show the message ‘error’ followed by one of the following:

‘Over temperature’

‘Data’

‘Battery low’

For further information on fault codes refer to Annex Q.2.

If the handset is not used for 15 minutes the display will enter a standby mode. This is shown by a slowly scrolling start-up message. Press any key to reactivate the handset.

Interpretation of results a) Test failure

If all tests fail, check the condition of the AWS fault tester and peripheral wiring.

b) System confirmation If any of the flux polarity and magnet sequence (for example S-N) passes then this demonstrates that the vehicle AWS equipment is functional but not necessarily within specification.

If the test fails at the minimum flux density of 100% but passes at higher-level settings a check should be made of the receiver height, to ensure the receiver height is within specified limits.

If the test passes the ‘shall not detect’ flux density a check should be made of the receiver height, to ensure the receiver height is within specified limits.




c) Depot maintenance obligations The AWS fault tester shall not negate the Railway Group Standard (GE/RT8035) requirements for the AWS system to be tested before entering service on an AWS test magnet, normally positioned in advance of the Network Rail controlled infrastructure.

d) Suspected ‘wrong side’ failure If a vehicle has been involved in a suspected ‘wrong side’ failure and all required tests have been passed in a situation fully investigated it may not be necessary to change any train borne equipment.

e) Class benchmarking In addition to fault diagnostic and rectification at the discretion of the vehicles’ maintenance authority, the AWS fault tester can be used to benchmark the sensitivity on the AWS receiver. When used for this purpose consideration shall be given to marginal failure results, due to variations in the AWS system tolerance.

At the users discretion a benchmarked vehicle with a marginal failure condition and no history of AWS receiver related failures could be deemed acceptable to continue in service providing it passes the Railway Group Standard depot test requirement, for example passes the AWS track- mounted depot test magnet test.




Appendix O AWS testing using Unipart Rail test equipment

O1 Isolate the AWS/TPWS control unit, for example by placing the battery switch to isolate.

O2 Disconnect the terminal box plug and socket harnesses from the AWS/TPWS control unit and connect the Unipart Rail test box between the harnesses and the control unit.

O3 Apply power to the control unit and carry out the tests in N4 to N13 recording the results on a fault finding test sheet (see Appendix T for a typical fault finding test sheet).

O4 Activate the cab to energise the AWS system and observe the LEDs on the Unipart Rail test box. The 12V, 40V, HORN, RECEIVER NORTH, the three CONTROL PANEL LEDs should illuminate and the INDICATOR BLACK should illuminate and then extinguish.

O5 Check that the voltage converter 12V and 40V supply LEDs are lit. If either LEDs are not illuminated the output voltage is outside of specified limits, exact voltages can be measured at the test box jack plugs using a volt meter and should be within the range 11.5V to 14.5V (nominal 12V supply) and 35V to 80V no load (nominal 40V supply)

O6 Press and release the TEST RESET pushbutton adjacent to the 12V supply LED, all the red TEST button LEDs should be extinguished. The amber indicator LEDs, green TPWS button LEDs and the three CONTROL PANEL LEDs should illuminate and extinguish.

O7 Press and release the AWS reset pushbutton in the cab, check that the RESET LED illuminates and extinguishes on the diagnostics handset.

O8 Check the control unit brake relay: • press and release the red BRAKE TEST pushbutton, which should illuminate • Press and release the red RECEIVER TEST pushbutton, which should illuminate • Press and hold the black SIMULATE RECEIVER pushbutton to simulate an AWS

caution - the RECEIVER NORTH LED should extinguish, the INDICATOR BLACK LED should momentarily illuminate, the RECEIVER SOUTH and HORN LEDs should illuminate - the AWS caution (horn/alarm) should sound and the AWS Indicator should change to ‘all black’ in the cab

• Release the SIMULATE RECEIVER pushbutton - the BRAKE LED should extinguish 2.5 to 3.0 seconds after the audible caution indication starts to sound indicating a brake demand application has been made and the red CONTROL PANEL BRAKE red LED should flash - the vehicle brakes should apply and the control panel/driver’s display brake demand lamp should flash

• Press and release the black AWS RESET pushbutton - the RECEIVER SOUTH and HORN LEDs should extinguish, the INDICATOR YELLOW LED should momentarily illuminate, the RECEIVER NORTH LED should illuminate and the CONTROL PANEL red BRAKE LED should change to a steady state - the BRAKE LED should remain extinguished for a further 60 seconds after which the vehicle brakes can be released, the CONTROL PANEL red BRAKE LED should extinguish and the BRAKE LED illuminate

• Press and release the black RESET/LAMP TEST pushbutton

O9 Caution test (horn/alarm tone): • Press and release the red HORN TEST pushbutton - the HORN LED should

extinguish and the AWS caution tone should sound continuously in the cab • Press and release the green HORN TPWS pushbutton - the HORN LED should

extinguish and the AWS caution tone should silence




O10 Indicator display test:

• Press and release the red INDICATOR BLACK TEST pushbutton - the INDICATOR BLACK LED should illuminate and the AWS indicator should show ‘all black’ in the cab (in both cabs of a dual cab vehicle fitted with a single AWS/TPWS control unit)

• Press and release the red INDICATOR YELLOW TEST pushbutton - the INDICATOR BLACK LED should extinguish, the INDICATOR YELLOW LED should illuminate and the AWS indicator should show ‘black and yellow’ in the cab (in both cabs of a dual cab vehicle fitted with a single AWS/TPWS control unit)

• Press and release the red INDICATOR BLACK TEST pushbutton - the INDICATOR YELLOW LED should extinguish, the INDICATOR BLACK LED should illuminate and the AWS indicator should show ‘all black’ in the cab (in both cabs of a dual cab vehicle fitted with a single AWS/TPWS control unit)

• Press and release the green INDICATOR BLACK TPWS pushbutton - the INDICATOR BLACK LED should extinguish and the AWS indicator in the cab should show ‘all black’ (in both cabs of a dual cab vehicle fitted with a single AWS/TPWS control unit)

O11 Simulated AWS clear signal: • Press and release the red RECEIVER TEST pushbutton - the NORTH LED should

illuminate and the SOUTH LED should remain unlit • Press and then immediately release the black SIMULATE RECEIVER pushbutton to

simulate an AWS clear signal • Check that the NORTH LED extinguishes and the SOUTH LED illuminates, the

INDICATOR BLACK LED momentarily illuminates and the AWS indicator is set to ‘all black’ in the cab (in both cabs of a dual cab vehicle fitted with a single AWS/TPWS control unit)

• Check that the NORTH LED then illuminates and the SOUTH LED extinguishes, and the audible AWS clear indication (bell/chime) sounds in the cab

• Press and release the green RECEIVER TPWS pushbutton

O12 Simulated AWS caution signal and AWS reset: • Press and release the red RECEIVER TEST pushbutton - the NORTH LED should

illuminate and the SOUTH LED should remain unlit • Press and hold the black SIMULATE RECEIVER pushbutton until the audible AWS

caution tone (horn/alarm) is heard in order to simulate an AWS caution signal. Immediately release the black SIMULATE RECEIVER pushbutton after the caution indication sounds

• Press and immediately release the black AWS RESET pushbutton within 2.5 seconds of the horn sounding to cancel the audible caution indication and reset the AWS system

• Check that the NORTH LED extinguishes and the SOUTH LED illuminates, the INDICATOR BLACK LED momentarily illuminates and the AWS indicator is set to ‘all black’ in the cab (in both cabs of a dual cab vehicle fitted with a single AWS/TPWS control unit)

• Check the HORN LED illuminates and the audible AWS caution indication sounds in the cab, and the NORTH LED then illuminates and the SOUTH LED extinguishes

• Check the HORN LED extinguishes, the audible AWS caution indication silences in the cab and the YELLOW LED momentarily illuminates and the AWS indicator is set to ‘yellow and black’ in the cab (in both cabs of a dual cab vehicle fitted with a single AWS/TPWS control unit)





O13 Simulated AWS caution signal and AWS brake application:

• Press and release the red RECEIVER TEST pushbutton - the NORTH LED should illuminate and the SOUTH LED should remain unlit

• Press and hold the black SIMULATE RECEIVER pushbutton until the audible AWS caution tone (horn/alarm) is heard in order to simulate an AWS caution signal. Immediately release the black SIMULATE RECEIVER pushbutton after the caution indication sounds

• Allow a vehicle brake application to occur, this should take place approximately 3 seconds after the audible caution indication commences - the red CONTROL PANEL BRAKE LED should flash to signify that a brake application has occurred

• Press and immediately release the black AWS RESET pushbutton to cancel the audible caution indication and reset the AWS system - the red CONTROL PANEL BRAKE LED should change to a steadily illuminated state and extinguish after 60 seconds (timed from the start of the brake application)

• Check that the NORTH LED extinguishes and the SOUTH LED illuminates, the INDICATOR BLACK LED momentarily illuminates and the AWS indicator is set to ‘all black’ in the cab (in both cabs of a dual cab vehicle fitted with a single AWS/TPWS control unit)

• Check the HORN LED illuminates and the audible AWS caution indication sounds in the cab, and the NORTH LED then illuminates and the SOUTH LED extinguishes

• Check the red TPWS CONTROL PANEL BRAKE LED flashes and the YELLOW LED momentarily illuminates, and that the cab mounted control panel brake demand indicator flashes and the AWS Indicator is set to ‘yellow and black’ in the cab (in both cabs of a dual cab vehicle fitted with a single AWS/TPWS control unit)

• Check the HORN LED extinguishes, the red TPWS CONTROL PANEL BRAKE LED becomes illuminated steady state, the TPWS cab mounted control panel brake demand indicator becomes steady state and the audible AWS caution indicator silences in the cab





Appendix P Fore and aft positions for AWS receivers Fore and aft positions for various AWS receiver designs




Fore and aft positions for Thales AWS receiver designs




Fore and aft positions for Unipart Rail electronic AWS receivers




Description of fault codes

Handset display Meaning Recommended action

Over temperature

The equipment case thermal device has overheated caused either by very frequent use at high energy levels (for example extra strength magnet at 20 mph) or a fault in the output drive circuits.

If the tester has had very frequent use switch the equipment off for 15 minutes and retest. If the fault report persists return to the manufacturer for repair.

Data There is a fault in either the data line, the handset or the supply to the handset.

The equipment should be returned to the manufacturer for repair.

Battery low The battery voltage is too low for the test to be accurately completed.

Fully charge the battery and then retest.

Examples of AWS receiver sensitivity table

Class: Vehicle no.: Maximum speed of vehicle: Receiver height range – receiver height: Test mode – standard strength magnets: Receiver type:

Speed

125 F P P P P P P P P








50 70 80 90 100 105 110 120 130 140 150 200

Flux density percentage

All green shaded tests must pass up to the next speed above the vehicles’ maximum speed and all red shaded tests must fail for the standard strength magnet test.




Class: Vehicle no.: Maximum speed of vehicle: Receiver height range – receiver height: Test mode – standard strength magnets: Receiver type:

Speed

100 F P P P

90 F P P P

80 F P P P

60 F P P P

40 F P P P

20 F P P P

70 80 90 95 100 105 110

Flux density percentage

All green shaded tests must pass up to the next speed above the vehicles maximum speed and all red shaded tests must fail for the extra strength magnet test.




Specification

Power requirements

Internal sealed lead acid 24 volt battery 240v ac input for battery charger

Display legends

Default setting standard Magnet setting

Standard Extra

Standard magnet Extra strength magnet

Default setting: S-N Test sequence

S N S-N N-S N-S-N

South polarity North polarity South followed by north polarity North followed by south polarity North followed by south followed by north polarity

Default setting: 100% of standard strength flux

Power level Standard strength Extra strength

Flux

50% of full power 70% of full power 80% of full power 90% of full power 95% of full power 100% of full power 105% of full power 110% of full power 120% of full power 130% of full power 140% of full power 150% of full power 200% of full power

1.50mT 2.17mT 2.48mT 2.79mT Not available 3.10mT Not available 3.41mT 3.72mT 4.03mT 4.34mT 4.65mT 6.20mT

Not available 3.5mT 4.0mT 4.5mT 4.75mT 5.00mT 5.25mT 5.5mT Not available Not available Not available Not available Not available

Default setting: 125 mph

Standard strength Extra strength

Speed setting

20 mph 40 mph 60 mph 80 mph 90 mph 100 mph 110 mph 125 mph

20 mph 40 mph 60 mph 80 mph 90 mph 100 mph Not available Not available




Illustration of parts and connection details

STA

ND

AR

D

125m

ph

S -

N

100%

SE

LEC

TTE

ST

STS

SIG

NA

LS L

TDA

WS

FA

ULT

TE

STE

R




Appendix Q AWS/TPWS testing using Thales depot test unit The following information has been extracted from Thales document OP606401 issue D dated 8/9/2000. Readers should consult Thales for any updated versions of this document. The Thales DTU is a portable unit powered from the vehicle under test for verifying the correct functioning of circuits external to the AWS/TPWS control unit. The DTU is capable of exercising and confirming the correct operation of the PSU, AWS receiver, AWS alarm and indicator unit, reset/acknowledge pushbutton, TPWS driver’s control panel, temporary isolation switch, timer link settings, TPWS aerial and of simulating a brake demand. The DTU is plugged into the train installation in place of the combined AWS/TPWS control unit. The DTU will switch, on demand, signals to operate visual indicators and audible sounders in the driver’s cab and has on its front panel LED indicators to confirm operation of the driver’s AWS/TPWS control panel switches. Correct power supply operation is confirmed by visual indicators. The DTU will also indicate short circuits existing in the TPWS aerial. The Figure below shows the layout of the front panel of the Thales DTU, which comprises groups of lamps and switches, each group for testing one item of equipment.

Figure 71 Thales Depot Test Unit (DTU) front panel

Controls and indictors

Power supply 2 pairs of green/red indicators to give an OK/HIGH indication for the 12V dc and 40V dc supplies. The thresholds are set to upper and lower limits of the permitted voltage ranges.

AWS alarm and indicator 4 momentary operation switches are used to operate the AWS visual indicator and sound the clear and caution indications. The ‘sunflower’ switches are interlocked so that both outputs cannot be energised simultaneously. In the event of a fault on any one of these external loads resulting in an overload current above 1.2A will cause the FAULT indicator to illuminate.

AWS receiver 2 lamps to indicate the state of the AWS receiver and a momentary switch to provide a reset (via the acknowledge switch and ‘sunflower’ proving contact). The receiver operation can be checked with a standard hand-held AWS test magnet.

AWS reset A single lamp is provided to verify operation of the AWS reset pushbutton.




Controls and indictors

TPWS driver’s control panel 3 switches to operate each of the driver’s control panel indicators and one lamp to verify operation of the TSO pushbutton.

TPWS temporary isolation 2 lamps to verify operation of both actions of the temporary isolation switch.

TPWS timer setting links 5 lamps to indicate the presence of wired links for TSO, ACK, ST0, ST1 and ST2 when specified and fitted.

TPWS aerial A momentary action switch and 2 lamps to indicate ‘OK’ (correct load), ‘short circuit’ or ‘open circuit’. Additionally, a single lamp to indicate an open circuit test loop.

Brake control A momentary action switch will open the brake circuit causing a brake demand.

Equipment set-up The DTU is plugged into the train installation in place of the combined

AWS/TPWS control unit. Remove the plug and socket connected to the control unit and attach the socket and plug on the DTU extension lead. An earth connection can be made to the TPWS equipment earth stud on the control unit terminal box.

Trainborne power supplies

Check that:

• Power supply 12V OK LED is lit on the DTU.

• Power supply 40V OK LED is lit on the DTU when the AWS Rx RESET switch is operated (note that the sunflower must be set to ‘Yellow/Black’ prior to this test.

(It is permissible for the 40V HIGH LED to be lit when the AWS Rx RESET switch is not operated).

If the 12V HIGH LED is lit or the 40V HIGH LED remains on when the AWS Rx RESET switch is operated, cease testing as the AWS Power Supply Unit is outside its normal operating limits and should be replaced.

Alarm and indicator unit/bell and horn test

Note that if the FAULT LED is lit when the SET BLACK, SET YELLOW/BLACK, BELL or HORN switches are operated, then disconnect PL1 connector since one or more of these circuits is likely to be short circuit to 0V. The threshold current is approximately 1.25A.

Indicator unit Operation Check

SET YELLOW/BLACK switch on the DTU

• the sunflower changes to the ‘yellow/black’ display

SET BLACK switch on the DTU • the sunflower changes to the ‘all black’ display

Leave in the ‘all black’ state in readiness for the AWS receiver reset test, and operate the BELL switch on the DTU

• the alarm and indicator unit chime (or the AWS bell) sounds according to the particular cab installation

Sunflower

Operate the HORN switch on the DTU

the alarm and indicator unit warning tone (or the AWS horn) sounds according to the particular cab installation




Indicator unit Operation Check

If these indications are reversed, pass the AWS test magnet north pole (red) under the AWS receiver

• the AWS Rx NORTH LED is lit • the AWS Rx SOUTH LED is not lit

Pass the AWS test magnet south pole (blue) under the AWS receiver

• the AWS Rx SOUTH LED is lit • the AWS Rx NORTH LED is not lit

Pass the AWS test magnet north pole (red) and then the south pole (blue) under the AWS receiver

• the indication changes accordingly

Operate the AWS Rx RESET switch (ensure the sunflower is showing ‘all black’)

• the AWS Rx SOUTH LED remains lit • the AWS Rx NORTH LED remains

not lit

AWS receiver test

Operate sunflower SET YELLOW/BLACK switch on DTU. With sunflower now showing ‘yellow/black’ operate the AWS Rx RESET switch

• the AWS Rx NORTH LED is now lit • the AWS Rx SOUTH LED is not lit

AWS reset/TPWS acknowledge test

Press and hold the AWS reset pushbutton in the cab

• The ACKNOWLEDGE LED is lit on the DTU and release the AWS reset pushbutton

Operate TPWS AERIAL TEST switch on DTU

If the AERIAL OK and SHORT LEDs are both extinguished then the aerial circuit is probably open circuit

TPWS aerial circuit tests

If the AERIAL OK LED is extinguished and the AERIAL SHORT LED is lit then the aerial circuit is probably short circuit and indicated if the dc resistance through the aerial is less than 50 Ohms approximately. If the TEST LOOP OPEN LED is lit, then only the test circuit is open circuit

• the AERIAL OK LED is lit • the TEST LOOP OPEN and AERIAL

SHORT LEDs are extinguished

With the trainborne temporary isolation switch held in the NORMAL position

• the TEMPORARY ISOLATION SWITCH ‘OFF’ LED is lit on the DTU

Hold the trainborne temporary isolation switch held in the ISOLATE position

• the TEMPORARY ISOLATION SWITCH ‘ON’ LED is lit on the DTU

TPWS temporary isolation switch test

Release the trainborne temporary isolation switch back to the central position

• neither TEMPORARY ISOLATION SWITCH LED is lit on the DTU

Press the trainborne TSO switch • the trainborne Brake Demand LED is lit

Operate the TSO LAMP switch on the DTU

• the trainborne TSO LED is lit

TPWS driver’s control panel tests

Operate the TEMPORARY ISOLATION/FAULT LAMP switch on the DTU

• the TSO LED on the DTU is lit




Indicator unit Operation Check Operate the BRAKE LAMP switch on

the DTU • the trainborne temporary

isolation/Fault LED is lit TPWS timer links • appropriate LEDs are lit depending on

the timer links fitted to this vehicle (if all links are fitted the ST0, ST1, ST2, ACK and TSO LEDs should be lit

Brake demand test Operate the BRAKE CONTROL switch on the DTU

• the train emergency brakes are applied whilst the switch is operated

Note that on some vehicles the emergency brakes may be latched on by this momentary breaking of the emergency brake circuit.




Appendix R TPWS testing unit Unipart Rail hand-held signal generator

The Unipart Rail hand-held TPWS signal generator is a portable, battery-operated unit designed for functional testing of the TPWS equipment overspeed sensor and train stop functions. It uses a standard TPWS track-mounted transmitter loop to transmit the TPWS frequencies and signal strength, and can be operated by one person from the driving cab. The following is extracted from section 5 of Unipart Rail document reference NRSSPECXSA003/11 issue D dated October 2003. It is recommended that users check with the manufacturer for any future updates of the instruction manual. Connect the TPWS signal generator test equipment to the vehicle as detailed in the operating manual.

Test type Operation Check

Open up the cab or follow the necessary procedure to activate TPWS

• if the AWS visual indicator (sunflower) starts at ‘all black’ then it changes to ‘yellow/black’ then to ‘all black’. If the AWS visual indicator (sunflower) starts at ‘yellow/black’ then it changes to ‘all black

• the 3 LED indicators on the TPWS driver’s control panel all illuminate (not flashing)

• the AWS audible warning sounds after approximately 3 seconds

Power up sequence test

Once the above events have been checked, cancel the AWS warning by pressing and release the AWS reset pushbutton

• the AWS audible warning changes to a bell/chime tone and then stops

• all 3 TPWS LED indicators on the TPWS driver’s control panel extinguish

• the AWS visual indicator (sunflower) changes to ‘yellow/black’ and the brakes release

If fitted, set the vehicle brake selector switch or passenger/goods switch to the passenger setting

TPWS train stop tests – passenger timings

Turn the signal generator PASSENGER/FREIGHT switch to PASSENGER

Normal direction: Press and hold the TRAIN STOP NORMAL DIRECTION pushbutton on the hand-held signal generator until the SEQUENCE COMPLETE LED illuminates

• the BRAKE DEMAND indicator on the driver’s control panel starts flashing

• an emergency brake application is made

Train stop tests – FORWARD

Within approximately 20 seconds of the brake demand, press and release the TPWS acknowledge pushbutton

• the BRAKE DEMAND indicator on the driver’s control panel changes to a steady illuminated state

• the BRAKE DEMAND indicator on the driver’s control panel extinguishes after approximately 1 minute after starting to flash, and the brakes release





Wrong direction: Press and hold the TRAIN STOP WRONG DIRECTION pushbutton on the hand-held signal generator until the SEQUENCE COMPLETE LED illuminates



Train stop tests – FORWARD




Normal direction: While pressing the OPPOSITE DIRECTION pushbutton on the hand-held signal generator, press and hold the NORMAL DIRECTION TRAIN STOP pushbutton until the SEQUENCE COMPLETE LED on the signal generator illuminates

• the BRAKE DEMAND indicator on the driver’s control panel remains unlit

• a brake application is not made

Train stop tests - reverse

Wrong direction: While pressing the OPPOSITE DIRECTION pushbutton on the hand-held signal generator, press and hold the WRONG DIRECTION TRAIN STOP pushbutton until the SEQUENCE COMPLETE LED on the signal generator illuminates



High speed, forward - normal direction: Press and hold the NORMAL DIRECTION OSS FAST pushbutton on the hand-held signal generator until the SEQUENCE COMPLETE LED illuminates






TPWS overspeed sensor tests – passenger timings

Wrong direction: Press and hold the WRONG DIRECTION OSS FAST pushbutton on the hand-held signal generator until the SEQUENCE COMPLETE LED illuminates










High speed, reverse – normal direction: While pressing the OPPOSITE DIRECTION pushbutton on the hand-held signal generator, press and hold the NORMAL DIRECTION OSS FAST pushbutton until the SEQUENCE COMPLETE LED on the signal generator illuminates



While pressing the OPPOSITE DIRECTION pushbutton on the hand-held signal generator, press and hold the WRONG DIRECTION OSS FAST pushbutton until the SEQUENCE COMPLETE LED on the signal generator illuminates



Low speed, forward – normal direction: Press and hold the NORMAL DIRECTION OSS SLOW pushbutton on the hand-held signal generator until the SEQUENCE COMPLETE LED on the signal generator illuminates



TPWS overspeed sensor tests – passenger timings

Wrong direction: Press and hold the WRONG DIRECTION OSS SLOW pushbutton until the SEQUENCE COMPLETE LED on the signal generator illuminates



TSO – passenger timings

Time-out: Press the TSO pushbutton on the driver’s control panel

• the TSO LED on the driver’s control panel illuminates immediately and then extinguishes after 20 seconds (+/-1s) or 60 seconds (+/-1s) dependent on the link arrangement within the control unit junction box





Train stop: Press the TSO pushbutton on the driver’s control panel and check that the TSO LED on the driver’s control panel illuminates. Within approximately 10 seconds press the NORMAL DIRECTION TRAIN STOP pushbutton on the hand-held signal generator until the SEQUENCE COMPLETE LED illuminates

• the TSO LED on the driver’s control panel extinguishes

• the BRAKE DEMAND LED on the driver’s control panel remains unlit


Overspeed sensor: Press the TSO pushbutton on the driver’s control panel and check that the TSO LED on the driver’s control panel illuminates. Within approximately 5 seconds press the NORMAL DIRECTION OSS FAST pushbutton on the hand-held signal generator until the SEQUENCE COMPLETE LED illuminates

• the BRAKE DEMAND LED on the driver’s control panel starts flashing

• the TSO LED on the driver’s control panel remains illuminated

• a brake application is made

TSO – passenger timings

Within approximately 5 seconds press and release the desk mounted TPWS acknowledge pushbutton

• the BRAKE DEMAND LED on the driver’s control panel changes to steady state

• the TSO LED on the driver’s control panel extinguishes after 20 seconds (+/-1s) or 60 seconds (+/-1s) as appropriate after the TSO pushbutton was pressed

• the BRAKE DEMAND LED on the driver’s control panel changes extinguishes after approximately 1 minute after starting to flash and the brakes release

Train stop tests – freight timings

If fitted, set the vehicle brake selector switch or passenger/freight cock to freight/goods timings Turn the TPWS signal generator PASSENGER/FREIGHT switch to FREIGHT and repeat operation for TPWS train stop tests - passenger timings

Overspeed sensor tests – freight/goods timings

Repeat operation for TPWS overspeed sensor tests – passenger timings

TSO tests – freight/goods timings

Repeat operation for TSO – passenger timings





Temporarily isolate the TPWS by turning the cab mounted temporary isolation switch to ISOLATE and then release the switch.

• the TEMPORARY ISOLATE/FAULT LED on the driver’s control panel illuminates

Train stop: Press and hold the NORMAL DIRECTION TRAIN STOP pushbutton on the hand-held signal generator until the SEQUENCE COMPLETE LED illuminates

• the BRAKE DEMAND LED on the driver’s control panel remains unlit and no brake demand is initiated

• the TEMPORARY ISOLATION LED on the driver’s control panel remains lit

Overspeed sensor: Press and hold the NORMAL DIRECTION OSS FAST pushbutton on the hand-held signal generator until the SEQUENCE COMPLETE LED illuminates

• the BRAKE DEMAND LED on the driver’s control panel remains unlit and no brake demand is initiated

• the TEMPORARY ISOLATION LED on the driver’s control panel remains lit

Temporary isolation

Put the TPWS to normal by turning the temporary isolation switch to NORMAL and release it.

• the TEMPORARY ISOLATION LED on the driver’s control panel extinguishes

There are additional testing requirements for single cab vehicles that are fitted with two TPWS aerials, for example steam locomotives. On single cab vehicles that are fitted with two TPWS aerials, the aerial integrity test performed during power up testing at system switch on will only test the integrity of the selected aerial. To confirm the integrity of both aerials, it is necessary to follow the following process:

Ensure that the TPWS system is switched off Select forward aerial (this will normally be selected by selecting forward gear) Switch the TPWS system on

• the power up test completes correctly

Additional testing requirements for single cab vehicles fitted with two TPWS aerials

Select the reverse aerial (this will normally be selected by selecting reverse gear) Switch the TPWS system off Wait approximately 5 seconds, switch the TPWS system on

• the power up test completes correctly




Appendix S TPWS testing using Thales train test unit The Thales train test unit (TTU) is a portable, battery operated unit designed for functional testing of the TPWS equipment overspeed sensor and train stop functions. It uses a standard TPWS track-mounted transmitter loop to transmit the TPWS frequencies and signal strength, and can be operated by one person from the driving cab. The following is extracted from section 3 of Thales document reference OP608527 Issue D dated 21 October 2005 . It is recommended that users check with the manufacturers for future updates. Figure 72 shows the typical set up of the TTU system. Warning: The separate items of the TTU are classified and calibrated as a single item of test equipment. It is not permissible to separate and mix items from different test equipments. This will render the calibration void.

The TTU should be positioned in the driving cab where the active TPWS driver’s display unit can be observed. Connect the connection cable to the coupling link and the transmitter loop.

It is important that the centre of the transmitter loop is located directly below the trainborne TPWS aerial although the train aerial may be laterally displaced from the longitudinal track centreline.

Test equipment setup

It is also important that the Transmitter Loop remains horizontal across the rails and undisturbed for the series of tests. For a track location or in an inspection pit, it is preferable to connect all cables and links before locating the track loop so as not to subsequently disturb it from its position on the rails.

Figure 72 Typical Thales trainborne equipment set-up for TTU operation




Test procedures Action Result

Switch on the Trainborne TPWS equipment, wait 3 seconds and press the acknowledge pushbutton to silence the AWS horn and brake demand.

• all 3 LED indicators on the driver’s control panel are unlit

Set the overspeed sensor timer link switches on the TTU to match those of the vehicle under test.

Refer to overspeed sensor timer settings. If the vehicle is fitted with a passenger/goods changeover switch, the overspeed sensor tests should be carried out on both settings.

Set both attenuator switches on TTU to 0dB and press any of the pushbutton function switches.

• the FAULT lamp will illuminate if the load or cable is disconnected or faulty and the BATTERY OK lamp will illuminate if the TTU battery state is satisfactory

Trainborne equipment power up

Note that the FAULT indicator should remain unlit for all of the following tests. If it lights during any operation then it indicates a fault on the output of the TTU due to the connection cable, coupling link or transmitter loop. This could include a short circuit between a cable screen and either line. Any faults must be rectified before proceeding with the tests.

• the BATTERY OK indicator should remain illuminated during the 3 second test duration only

Vehicle sensitivity test: This is a special test only. Normally set the attenuator to the value specified in the vehicle maintenance instructions and leave at this setting for the remainder of the tests.

Set ATTENUATOR switches to the maximum (39dB)

• the TRAIN STOP NORMAL DIRECTION LED on TTU lights for approximately 3 seconds

Press TRAIN STOP NORMAL DIRECTION and progressively reduce the attenuation until a brake demand occurs (typically between 13 and 23dB)

• the BRAKE DEMAND LED on driver’s control panel starts flashing

Press and release the acknowledgement pushbutton on the driver’s desk within 20 seconds of the brake demand

• the BRAKE DEMAND LED on driver’s control panel changes to illuminated steady

Wait for the one minute brake demand to time-out

• the BRAKE DEMAND LED on driver’s control panel extinguishes approximately one minute after starting to flash and brakes released

Record attenuator settings as ‘vehicle sensitivity'





Train stop tests (forward)

Set train direction controller to FORWARDSet TRAIN SPEED on TTU to LOW (this setting does not affect the test)

Press TRAIN STOP NORMAL DIRECTION


• the BRAKE DEMAND LED on driver’s control panel starts flashing and emergency brakes are applied

Normal direction (forward)




Press TRAIN STOP WRONG DIRECTION

• the TRAIN STOP WRONG DIRECTION LED on TTU lights for approximately 3 seconds


Wrong direction (forward)




Train stop tests (reverse)

Set the ATTENUATOR on 0dB Set train direction controller to REVERSE Set TRAIN SPEED on TTU to LOW (this setting goes not affect the test)

Train stop normal direction (reverse)

Press TRAIN STOP NORMAL DIRECTION


• the BRAKE DEMAND LED on driver’s control panel remains unlit

• the Emergency brakes are not applied





Train stop wrong direction (reverse)

Press TRAIN STOP WRONG DIRECTION

• the TRAIN STOP WRONG DIRECTION LED on TTU lights for approximately 3 seconds



Overspeed sensor tests (high speed, forward)

Set train direction controller to FORWARD Set TRAIN SPEED on TTU to HIGH

Press OVERSPEED SENSOR NORMAL DIRECTION

• the OVERSPEED SENSOR NORMAL DIRECTION LED on TTU lights for approximately 3 seconds


Normal direction (forward)




Press OVERSPEED SENSOR WRONG DIRECTION

• the OVERSPEED SENSOR WRONG DIRECTION LED on TTU lights for approximately 3 seconds


Wrong direction (forward)




Set train direction controller to REVERSE Overspeed sensor tests (high speed, reverse) Set TRAIN SPEED on TTU to HIGH





Overspeed sensor normal direction (high speed, reverse)





Overspeed sensor wrong direction (high speed, reverse)





Set train direction controller to FORWARD

Overspeed sensor tests (low speed, forward) Set TRAIN SPEED on TTU to LOW

Overspeed sensor normal direction (low speed, forward)





Overspeed sensor wrong direction (low speed, forward)





If the TSO timer for the vehicle is set to 20 seconds then: Press the TSO pushbutton on the driver’s control panel

• the TSO LED on driver’s control panel illuminates immediately and extinguishes after approximately 20 seconds

TSO tests: TSO time-out

If the TSO timer for the vehicle is set to 60 seconds then: Press the TSO pushbutton on the driver’s control panel

• the TSO LED on driver’s control panel illuminates immediately and extinguishes after approximately 60 seconds




Test procedure Action Result

Set the train direction controller to FORWARD

Press the TSO pushbutton on the driver’s control panel

• the TSO LED illuminates on driver’s control panel

TSO – train stop

Press TRAIN STOP NORMAL DIRECTION on TTU within 10 seconds

• the TRAIN STOP NORMAL DIRECTION LED on TTU illuminates for approximately 3 seconds

• the TSO LED on driver’s control panel extinguishes immediately



Set the TRAIN DIRECTION switch on the TTU to FORWARD

Set the TRAIN SPEED switch on the TTU to HIGH

Press the TSO pushbutton on the driver’s control panel

• the TSO LED illuminates on driver’s control panel

Press OVERSPEED SENSOR NORMAL DIRECTION on TTU within 10 seconds

• the OVERSPEED SENSOR NORMAL DIRECTION LED on TTU illuminates for approximately 3 seconds


TSO – overspeed sensor


• the BRAKE DEMAND LED changes to illuminated steady on driver’s control panel

• the TSO LED on driver’s control panel remains lit for 20 or 60 seconds according to vehicle timer setting

• the BRAKE DEMAND LED on driver’s control panel extinguishes approximately one minute after starting to flash and emergency brakes are released





Cut the security seal (if fitted) on the cab mounted TPWS temporary isolation switch to allow it to be operated

Temporary isolation tests – selection

Select TEMPORARY ISOLATION by turning the switch to the isolate position and releasing

• the TEMPORARY ISOLATION/FAULT LED on the driver’s control panel illuminates

Set TRAIN DIRECTION on the TTU to FORWARD

Train stop

Press TRAIN STOP NORMAL DIRECTION on the TTU



• the TEMPORARY ISOLATION LED on the driver’s control panel remains illuminated

Set TRAIN DIRECTION on the TTU to FORWARD

Set TRAIN SPEED switch on TTU to HIGH

Overspeed sensor

Press OVERSPEED SENSOR NORMAL DIRECTION on the TTU



• the TEMPORARY ISOLATION LED on the driver’s control panel remains illuminated

Deselect TEMPORARY ISOLATION by turning the cab mounted temporary isolation switch to the NORMAL position and releasing.

Check that the TEMPORARY ISOLATION/FAULT LED on the driver’s control panel extinguishes

De-selection

If required, fit a new security seal to the temporary isolation switch




Test procedure Action

On completion of the tests disconnect the connection cable from the TTU and transmitter loop

Remove the transmitter loop and support beams from the rails and clear of the vehicle

Gather up the connection cable and store in the TTU lid

Test completion

Shut down the driving cab and make safe before leaving the vehicle

The nominal time between a pair of OSS frequency pulses is set by the three OVERSPEED TIMER LINK switches on the TTU. These must be set to match the setting of the overspeed sensor timer links on the vehicle being tested. The actual time between pulses will be either slightly above or below the nominal according to the setting of the TRAIN SPEED switch on the TTU as part of the test.

The nominal timer settings are shown below:

State Link switch 0

Link switch 1

Link switch 2

Nominal timer setting

Passenger Out Out In 974ms

Overspeed sensor timer settings

Goods In Out In 1218ms




Appendix T Typical AWS/TPWS fault finding test sheet The following is an example of an AWS/TPWS fault finding test sheet. The sheet is based on the use of the Unipart Rail AWS/TPWS test box as applied to a typical dual-cab locomotive. Vehicle No.

Reported AWS/TPWS fault code Fault present at: no. 1 end/no. 2 end/both ends

Functional tests: No. 1 end No. 2 end

TPWS energised and brakes released in cab where failure occurred

Pass/fail Pass/fail

Caution aspect test – south pole (blue) – horn and brakes Pass/fail Pass/fail

Clear aspect test – south pole (blue)/north pole (red) – bell only Pass/fail Pass/fail

Diagnostic test box results No. 1 end No. 2 end

12V LED illuminated Pass/fail Pass/fail

40V LED illuminated Pass/fail Pass/fail

Correct operation of AWS reset Pass/fail Pass/fail

Correct operation of brake relay function Pass/fail Pass/fail

Correct operation of caution tone (horn/alarm) Pass/fail Pass/fail

Correct operation of black and yellow indicator Pass/fail Pass/fail

Correct operation of all black indicator Pass/fail Pass/fail

Correct operation of clear tone (bell/chime) Pass/fail Pass/fail

Simulate AWS clear signal Pass/fail Pass/fail

Simulate AWS caution signal and reset Pass/fail Pass/fail

Simulate AWS caution signal and brake application Pass/fail Pass/fail

TPWS temporary isolation switch operation Pass/fail Pass/fail

TPWS overspeed sensor tests Pass/fail Pass/fail

TPWS train stop sensor tests Pass/fail Pass/fail

TPWS wrong direction sensor tests Pass/fail Pass/fail

TPWS train stop sensor override tests Pass/fail Pass/fail

Comments/observations

Signature: __________________________________________________ Name: _____________________________________________________ Date: ______________________________________________________ TEST SHEETS ARE TO BE RETAINED ON THE VEHICLE FILE FOR TWO YEARS




Appendix U Typical AWS/TPWS wrong side failure report form




Appendix V Typical labels for defective AWS/TPWS equipment The following is an example of a label that could be used to be attached to defective AWS/TPWS equipment requiring wrong side failure investigation:

AWS/TPWS EQUIPMENT FOR WRONG-SIDE FAILURE INVESTIGATION

ITEM: ………………………….. CAT NO: …………………………..

VEHICLE NO: ………………... FAULT CODE: …...…………………...

DATE OF FAULT: ….…………DATE OF REMOVAL: ………….....….

TRAIN OPERATOR: ……………………………………………………...

DEPOT NAME: ……………………………………………………………

FORWARD IMMEDIATELY TO ____________________________________ TECHNICAL INVESTIGATION CENTRE

URGENT HANDLE WITH CARE

The following is an example of a label that could be used to be attached to defective AWS/TPWS equipment requiring repair following a right side failure investigation:

AWS/TPWS EQUIPMENT FOR REPAIR

ITEM: ………………………….. CAT NO: …………………………..

VEHICLE NO: ………………... FAULT CODE: …...…………………...

NATURE OF DEFECT…………………………………..………….....….

TRAIN OPERATOR: ……………………………………………………...

DEPOT NAME: ……………………………………………………………

FORWARD TO _______________________________ REPAIR CENTRE

HANDLE WITH CARE




Definitions Above rail level This relates to a measurement to the top of the head of the running rail as a reference point.

ATOC Association of Train Operating Companies.

ATP Automatic Train Protection.

AWS Automatic Warning System.

C4 The basic running gear overhaul, generally at intervals of up to 500,000 -1,000,000 miles (2 to 7 years). It includes below sole bar work (for example running gear overhaul) and may include door-gear overhaul. For those fleets which do not have a C4 this term has been used to mean the equivalent mileage-driven running gear exam – for example a locomotive F exam.

C6 The basic time-driven passenger environment overhaul. Generally includes above sole bar work, and interior overhaul. C6 may be coupled to exterior painting. Typically 6 to 10 years.

Component tracking application The component tracking application is a web-based computer application operated by ATOC and designed to enable the rail industry to accurately track AWS and TPWS component fitment histories and defects.

DCP Driver’s control panel

DMM Digital multi-meter.

DTU Depot test unit.

E-AWS Electronic AWS (receiver).

EP Electro pneumatic.

FPGA Field Programmable Gate Array.

Maintenance depot A location identified within the railway undertakings (train operators) contingency plan with the facilities to maintain, repair or replace items of trainborne AWS equipment.

National Incident .Report (NIR) A report of an urgent safety-related defect relating to rail vehicles, equipment or plant and machinery using NIR-Online.




NIR-Online A web-based application used to initiate, disseminate and manage reports (known as national incident reports) or urgent safety-related defects relating to rail vehicles, equipment and plant and machinery. The web address of NIR-Online is http://www.nir-online.net/.

OSS Abbreviation for the TPWS OSS (overspeed sensor system).

An OSS is a facility whose function is to initiate a brake application on a train that approaches a signal showing a danger aspect, or an ‘other location’ at excessive speed.

PSU Power supply unit.

SPAD Signal passed at danger.

STM Abbreviation for Specific Transmission Module – an STM is a device that enables the European Train Control System to communicate with existing national train protection systems. The European Train Control System is a pan-European standard in-cab signalling system incorporating Automatic Train Protection.

TASS Abbreviation for Tilt Authority and Speed Supervision System. TASS is employed on lines and on tilting vehicles where tilting trains are permitted to traverse curves at higher speeds than conventional non-tilting trains. TASS provides a signal to permit tilt to take place and controls maximum train speed, overriding TPWS installed for speed restrictions.

TI Temporary isolation.

TIS Temporary isolation switch.

Train data recorder (TDR) For the purpose of this document, equipment provided on a train to record data about the operation of its controls and performance in response to those controls and other train control systems.

A data recorder is also referred to elsewhere as a data logger, event recorder, on-train monitoring and recording (OTMR) equipment and juridical recorder (JRU).

TPWS Train Protection and Warning System.

TPWS+ An arrangement of TPWS at certain high speed signal approaches which includes a second OSS in rear of the standard OSS, to protect against higher speed over-speeding within the standard overlap, generally up to around 100mph.

TSO TPWS train stop override.

The TSO is a facility that allows a train to pass a signal at danger, with the authority of the Signaller, without being tripped by the train stop system (TSS).




TSS TPWS train stop system.

A TSS is a facility whose function is to initiate a brake application on a train that passes a signal at danger without authority.

Target service life The service life that can be expected from a component without a significant risk of failure.

Train stops/tripcocks Trains stops are mechanical devices mounted at trackside to engage with tripcocks mounted in the braking system of vehicles. If the tripcock is triggered at a red signal by the train stop then the train brakes will automatically be applied.

TTU Train test unit.

Unipart Rail Formerly known as National Rail Service – name change was effected on 1 December 2006.

VFC Volt free contact.




References The Catalogue of Railway Group Standards and the Railway Group Standards CD-ROM give the current issue number and status of documents published by RSSB. This information is also available from www.rgsonline.co.uk.

Documents referenced in the text RGSC 01 The Railway Group Standards Code Railway Group Standards GE/RT8000 Rule Book GE/RT8026 Safety Requirements for Cab Signalling Systems GE/RT8030 Train Protection and Warning System GE/RT8035 Automatic Warning System GE/RT8250 Reporting High Risk Defects GI/RT7011 Provision, Risk Assessment and Review of Level Crossings GK/RT0038 Signalling of Permissible Speeds and Speed Reductions GK/RT0106 Management of Safety Related Failures of Signalling and Operational

Telecommunications System GM/RT2472 Train Data Recorders – Design Requirements GO/RT3437 Defective on Train Equipment Other references ACOP/EC/01001 Approved Code of Practice – AWS/TPWS Component Life

Instructions, Association of Train Operating Companies Handbook Number1395-1.G

TPWS Trainborne Equipment Maintenance Manual, Thales UK Limited, Land and Joint Systems

NRSSPECXSA003/01 TPWS Vehicle Sub-system Development – Installation Design Guide, Unipart Rail

NRSSPECXSA003/11 TPWS Vehicle Sub-system Test Equipment – Maintenance and Routine Depot Test Specification, Unipart Rail

NRSSPECXSA003/30 TPWS System Components and Technical Descriptions, Unipart Rail

OP606401 TPWS Depot Test Unit Operating Instructions, Thales UK Limited, Land and Joint Systems

OP608527 TPWS Train Test Unit Mark 2 Operating Instructions, Thales UK Limited, Land and Joint Systems

PTP604412-00 TPWS Trainborne Equipment Proof Test Procedure, Thales UK Limited, Land and Joint Systems

STS TY287 AWS Fault Tester Operating Manual, STS Signals Ltd TPWS/TIP/018 TPWS Technical Information Pamphlet, Electronic AWS Receivers,

Thales UK Limited, Land and Joint Systems


Combined AWS and TPWS Trainborne Eqpt.

Documents

12v negative

12v positive

12v dc pulse

sole bar work

temporary

white square

dmm reading

operational