Ship Stability for Mates/Mastersllrc.mcast.edu.mt/digitalversion/table_of_contents_35135.pdf · Section 15 Curves of Statical Stability for Varying Conditions. . . 153 Section 16

Witherbys Seamanship International Ltd.

Ship Stability for Mates/Masters

Martin A. Rhodes (BSc. Hons) Lecturer, Ship Stability,

Glasgow College of Nautical Studies

PUB LIS H I

p

-Chapter

Introduction .

CONTENTS

Section 1 Basic Principles .. ..... • .. • ..

Section 2 Form Coefficients.

Section 3 Tonnes Per Centimetre Immersion (TPC) ..... •. .• .. • _ . ... . • , . . ...

Section" Load Lines. . . . .. ........ .

Section 5 Centre of Gravity (G) and Centre of Buoyancy (6) .......•..

Section 6 Introduction to Transverse Statical Stability ..

Section 7 Conditions of Stability ............... .. .

Section 8 Initial Transverse Metacentre .. .. . .

Section 9 Free Surface Effect. .

Section 10 Curves of Statical Stability (GZ Curves)

Section 11 List . .... ... . .

Section 12 Introduction to Trim.

Section 13 Suspended Weights ...

Page

3

9

15

21

29

39

47

57

61

69

83

89

101

121

Section 14 Assessing Compliance of a Ship's Loaded Condition with IMO Criteria. 131

Section 15 Curves of Statical Stability for Varying Conditions. . . 153

Section 16 Wall-Sided Formula ....

Section 17 Factors Affecting the Shape of the Curve of Statical Stability ...

Section 18 The International Grain Code (IMO) .

Section 19 Inclining Experiment.

Section 20 Trim Using Hydrostatic Data .. .

Section 21 Dry-Docking .

Section 22 Bilging.

Section 23 Angle of Heel When Turning ..

Section 2. Wind Heeling. Ice Accretion and Rolling .

Section 25 Stability Problems Associated with Specific Ship Types ...

Section 26 Calculation and Assignment of Freeboard.

Section 27 Shear Forces and Bending Moments in Ships ....... .. .. . . . ... .

Section 28 Practical Ship Loading Problems ....

Bibliography.

161

171

185

215

223

253

265

291

297

317

345

371

383

401

p

Active stabilising fins .. Active systems

A Page .. 316

.... 315 Activo tanks .. .... ......... ... , .. ... ... ........... ..... . .. ... .. 315 Added weight method ... . .. ... .......... . .... 269 Additional conditions of assignment fOf type

'B-l00' freeboard (Regulation 27) .. .. .. ..... ..... 360 Additional conditions of assigflment for type

'B-60' freeboard (Regulation 27).. . ....... ", .. ... 359 Additional IMO criteria for passenger ships. ... . . ... " . ... 145 Advance.. . .. ' ............ , . . ' ... , ... 292 After PerpendiclJlar (AP). . . ..... .... .. 102 Amidships... . ........ ... ........ 102, 347 Amidships side compartment bilged ,. . . .. " . ......... . " .... 283 Angle of heel when turning ..... 29, 291 , 292, 295, 296. 342 Angle of list caused by a transverse shift of

weight GM=zero.. . .. 167 Angle of list, amidships side compartment bilged ........ . , , .. .. 286 AngleoOolL . ............. ... . . ... ... ....... 64, 156, 158. 165. 166 Angle of loll and list, procedures for correcting .. . .. 158 Angle of loll using wallsided formula .. . ..... ... .. 165 Angle of loll, curve of statical stability. ... . . ..... .. 156 Angle of 101, unstable condition .. ............. 60 Angle of repose .. . .. .. 186 Archlmedes' principle .. 12 Assessing compliance of a ship's loaded condition ..... ...... . 141

B S.60 and 8-100 tabular freeboards .. . ......... ... ... 359 Ballasting ...... ......... . . ... .. .. , , .. ... 202 Basic information available from the curve of

statical stability,. . .. ..... BB Basic principles.. .,.9 Beam.... .. ...... .... .... . 67 Bending momenls curve, producing ........ 326.329. 371,372,

375.381,382 Bilge keels .. Bilged end compartment, calculate draughts ,. Bilgng .. Bilging a compartment when permeability

.. .. 314 . .... ... ... 279

..... .. 265

is less than 100%,.. . .. .. .. .. . 274 Bilging an empty amidships oompar1ment.. . .. ... ........ .. ,., .266 Bilging an empty amidships compartm9l'1I

with a watertight flat. . Bilging an extreme end compartment with

100% permeability .. ~ing an extreme end compartment with

. . .... 271

. ... .... ... . ... 279

a watertight flat - 100% permeabi~ty ... ... ......... .... ... 2a1 Block coefficlent (CB).. . .. 17,347 Bow height .. .... ......... 361 , 363 Box shaped vessels (KM).. . ......... 62 Box~haped vessel, calculate displacement.. . ... ... 14 Breadth (b).. .. .. .. 347 Broaching.. . ...... ..... ... 151 Bulk carner concems.. . ...... 326 Bull<. carrier safety.. .. .. ... 327 Bulk earners. . .... ... .. 326 Bundling of bulk gain.. .. , .. .. .203

C Calculating final draught - ship initially even keel,. . ... .. .. .232 Cak:ulating final draught when a weight is shiftod .. . .. 111 Calculating GZ vakJes ..... .. ... ...... ..84 Calculating the change of trim, altemative formula ...... .... .. 250 Calculating the final draught - ship Initially trimmed.. . .... .. 233 calculating the final drau!j1ts.. ..248 Cak;ulating the Incr/deer in GZ as a resuH of

a change of KG . .. .. ...... 172 Calcwlating the km of a box-shaped vessel ......... ... ... 266 Calculating Ule list caused by a transverse shift of weight . .... 90 Calculating the list due to a single weight Ioadfdisch .... 92 CalCUlating the list when an amidships side compartment

is bilged - permeability 100% ... .......... .. ,. . . ... .... .. 283 Calculating the max draught due to listlheel .296

CLASS 211 STABILITY - Index

Page Calculating the moment of inertia of a box-Shaped

vessel, bilged side compartment .. ............. ... ........ 284 Calculating the P force.. . .. .. .. ..... ..... 256 Calculating the permeability for a compartment.. ..275 Calculating the true mean draught.. .. 225 Calculating the weight to load 10 reduce the deepest

draught I:1f a given amount. . Calculation and assignment of freeOOard .. ..

. .. 244 . ..345

Calculation conventions .. . .. ....... ... ....... 3a1 calculation inaccuracies.. . .... .. .. ... .... 149 Calculation of KG in the inclined condition.. ..217 Calculation of p force at any stage during dry-docking . ....... 256 Calculation of p force during the critical period

when dry -dOCking . ... .... ... .. ............... .... 256 Calculation of the ship's actual light kg and displacement ... 218 Calculation 01 the summer timber freeboard

(regulation 45) .. . .. ..... ....... ... .... 367 Calculation procedure for the assignment of a

type 'a' freeboard .. . ........ .... 361 Calculation procedure for the assignment of a

type 'b' frneboard .. . .... ..... 365 Cause of a change of trim due to change of

water density.. . .. ..... ..... 247 Causes 01 a change in freebOard .. . ..... 179 Causes of a Change in KG.. . ...... 172 Causes of a list....... ..... . .... ..... ... .... 175 Centre 01 buoyancy (B).. . . ..... . ..... .. ..... .45 Centre of gravity (G).. .40 Centre of gravity (G) and centre of buoyancy (B) .... . , .. ........ 39 Change in draught and trim due to change in

water density. ,. . ... .. .... ...... 247 Change of KG .. 172 Change of trim... .. .. .... .... . 105 Change of trim.. .. .. 105, 247, 250 Change of trim due to Change of density. . . ... ... 250 Change of trim due to change 01 density.. .,.247 Change of trim, altemative formula . , ....... ..... ........ .... ..... 250 Changes in stability caused by heaving. rolling

and pitching.. . ..... .... .. .... ........ .... 150 Checking compliance when the angle of progressive

flooding (GF) is greater than 400 .. Checking compliance when the angle 0( progressiva

.... 141

flooding (GF) is tess than 40G.. .. . ... . . ... .. . .. ..... 142 Coefficient of fineness of the waterplane area (CW). . . ...... 16 Comparison of even keel and stem trimmed stability

ch8l3C1eristics.. .184 Comparison of stability of a ship In lightnoaded conditions .. 180 Comparison of the two approaches to ship subdivision .... . 331 Compensation for the vertical component of shift of grain .. . 196 Conditions of assignment of freeboard applicable

to all ships... .. .. ....... .... 351 Conditions of stability.. .. .... 57 Curve of statieal stability for a listed ship ,.. . .... 157 Curve of statics! stabUlty for a ship in a neutral condition .... 155 Curve of statical stability for a ship in a stable condition . .. .. 154 Curve of statlcal stability, basic Information. . . .. as Curve of statical stability, effect of a change In freeboard .... 179 Curve of statlcal stability, effect of a change of KG . ..... ..... 172 Curve of staticsl stability, effed of a transverse shift

of weight (list) .... . ... 175 Curve of statleal stability, effect of Increasing beam.. . .. 1a2 Curve of stallcal stabUlty, effact of stem trim . ... ...... .... ...... 184 Curve of statical stability, effect on KG of lifting a weight ... .. 122 Curves ofstatlcal stabiility (GZ curves).. ..83 Curves of statlcal stability for stiff and tender ships .. .... ... ... a7 Curves of statical stabiUty for varying conditions.. .. . .. 153

D Damaged stability.. .1a3, 274, 324, 328, 330, 331 ,

337, 340,343, 356, 359 Damaged stability conskferations .. . .. .... .. ..... .... 324 Damaged stability requirements for ro-ro passenger ships .. 343 December 2002 solas amendments. . .... 329

405

Deck line . . ....................................................... 349 Definitions ......................................................... 347 Density.. . .................................................... 10, 81 Density of water in which a ship typically floats .................. 11 Density, mass and volume. 10 Depth for freeboard (d) ............................................... 347 Derivation of the FWA formula ........................................ 31 Derivation of the heeling arm ........................................ 194 Derivation of the inclining experiment formula ................. 217 Determining the GM by means of rolling period tests ......... 309 Deterministic approach to subdivision.. . .... 331 Deterministic rules for passenger ships ................... 331 Distinction between 'dynamica stability' and

'transverse statical stability' ............................... 137 Distinction between stability at small and large

angles of heel ................................................... 162 Distinction between type 'a' ships and type 'b'

ships explained ................................................... 358 Dock water allowance (DWA).. . .............................. 32 Document of authorisation to carry grain cargoes ............ 192 Double hull tanker lolling ........................................... 324 Double hull tankers. . ................................ 323 Draught marks and reading the draught ......................... 103 Draught, true mean .................................................... 224 Dry-docking.. . .................... 253 Dry-docking, sequence of events.. . .......................... 254 Dry-docking, typical problems ...................................... 259 DWNFWA to ensure maximum cargo is loaded ................. 34 Dynamic effects of ship's motion at sea ........................ 149 Dynamic moverrent of water on deck ............................ 151 Dynamical stability defined.. . ..... 136 Dynamical stability, area under the curve of

statical stability.. . ......................... 136

E Effect of a shift of solid bulk cargo on the curve

of statical stability.. . ......... 186 Effect of discharging a weight ...................................... .43 Effect of loading a weight .......................................... .41 Effect of shifting a weight already on board ..................... .41 Effect of steady wind moments or asymmetric icing... . ...... 150 Effect of stem trim and reserve forw ard buoyancy

on stability ........................................................ 319 Effect on the curve of statical stability of a change of KG .... 173 Effect on the curve of statical stability of a shift of

solid bulk cargo. ..... . ........................................... 188 Effect on the curve of statical stability of a trim

by the stem. . . . . . . .. . .............. 184 Effect on the curve of statical stability of an

increase in beam ........................................... 182 Effect on the curve of statical stability of

increase in freeboard ......................................... 179 Effect on the curve of statical stability of list .................. 176 Effects offree trim. . .. . . . . . . . . . . . . . . . . .. . ...................... 149 Entrapment ................................................. 172, 175,318 Entrapment of water in pipe cargoes ......................... 318 Examination style problems involving trim ....................... 237

F Factors affecting km ..................................................... 67 Factors affecting the shape of the curve of statical stability .171 Factors affecting TPC.. . ........................... 24 Factors influencing free surface effect .............................. 77 Final kg required to complete loading with a required GM ..... 65 Fixed trim' and 'free trim' basis KN curves .................... 321 Floodwater .................................... 289,270,271,274,328 Flush deck ship ................................................ 348 Forces that cause the ship to heel during turning .............. 293 Form coefficients ................................................. 15 Formula for calculating MeTC ..................................... 108 Formula for rolling period ......................................... 308 Forward perpendicular (FP) ...................................... 102 Free surface data. . ............................................... 71 Free surface data in tank sounding/ullage tables ................ 73 Free surface effect ................................................. 69 Free surface effect .... 60, 69, 70, 72, 77, 81, 99,100,159,193,

202,209,219,261,303,314,323,341, 343,354,358,366,368

CLASS 2/1 STABILITY - Index

Free surface effect and list... . . ................. 99 Free surface effect and the loss of transverse

statical stability.. . ........... ..70 Free surface effect in a rectangular shaped tank ............... 71 Free surface moments ............................................... 72 Free surface moments, important points to note ................. 82 Free Trim .................................................... 149,216,321 Freeboard. . ................................ 347 Freeboard deck.. . ....... 348 Freeboard limitation aft.. ..319 Freeboard, causes of a change ..................................... 179 Freeboard, conditions of assignment. ........................... 351 Freeboard, correction for block coefficient ..................... 361 Freeboard, correction for bow height. ......................... 363 Freeboard, correction for depth.. . ... 361 Freeboard, correction for position of deck line ................. 362 Freeboard, correction for sheer profile.. . ............. 363 Freeboard, correction for superstructure and trunks.. . .... 362 Fresh water allowance (FWA) ........................................ 31

G General principles of the international grain code ............. 190 Gm (effective) at the angle of loll.. . ........... 166 Grain code assumptions with respect to anticipated shift .... 190 Grain loading information to be supplied. . .. 192 Grain shift assumptions.. ..190 Gzandgmatsmallanglesofheel ............................... 147 Gz curves ............................................................. 83 Gz decrease as a result of a transverse shift of weight ..... 175 Gz values ............................................................. 84 Gz values, procedure for calculating.. . ... 84

H Heaving, changes in stability.. . ...................... 150 Heeling arm.. . ....... 194 Hold cargo information sheet.. ................................ 384 Hydrometer, the ship as a.. ..31

I Ice accretion ............. 150,172,175,179,297,300,368,369 Icing ................................................................. 150 Icing allowances.. . .......... 304 Inclining experiment. ................... .48, 149,215,217,222,355 Inclining experiment and lightweight survey,

when they must be conducted.. 222 Inclining experiment formula. . ........................... 217 Inclining test, preparations.. . .................... .219 Increase in draught due to list/heel.. . ...................... 296 Information regarding ship's stability and grain loading ...... 192 Information to be supplied to the master.. . ............. 351 Initial transverse metacentre.. . ...... 52,61 Intact stability criteria for cargo ships .......................... 139 Intact stability criteria for passenger ships. . ......... 146 Intact stability criteria for ships canying grain ................. 193 Intact stability criteria for supply vessels ...................... 322 International grain code.. . ................... 185 International grain code, minimum criteria.. . .. 198 Introduction to loading sheet data.. . ......... 384 Introduction to transverse statical stability.. . ..... .47 Introduction to trim.. . .................. 101

K Kg, causes of a change. . .. 172 Kg, maximum permissable prior to loading or

discharging a weight.. . ... 128 Km for box-shapedvessels ........................................ 62 Kn values. . ............... 84

L Law of flotation. . .. . ...... 12, 13 Length (L).. ..347 Length between perpendiculars (LBP) ......................... 1 02 Length overall (LOA). 102 Light displacement and KG assumptions. . .............. 149 Lightweight survey. . .. ........ 222 Limiting the loss of GM.. . ...... 261 List ...................................................................... 89 List and free surface effect.. 99

406

.. • ; .

ji

list caused by a transverse and vertical shift of weight ...... .. 91 List, causes. . . . .. ... ..... 175 Load a single weight to keep the aft draught constant. ... ..243 Load line calculations.. . .. 34 Load line certification and surveys .. .. ", . ...... 370 load line dimensions ..... 30 Load line mark.. ..349 Load line survey preparation... . . ... 370 load lines.. . ... 29 Load/discharge problems. . . .. ........ 26 loaded condition, assessing compliance.. . . .. 141 Loading a weight using ship's lifting gear.. . .... ...... ... ..... 124 loading weights about the centre line to complete upright. .. . 97 loadingfdischarging operations at sea.. . .......... 318 Longitudinal centre of flotation (LCF or F). ..... . .. 110 longitudinal prismatlc coefficient (CP).. . 19 Loss of GM. .. ..... 72, n, 80,81,82, 158, 159,257,258,

259,261,262.323,341,343 Loss of GM as a result ot a fall in M (decrease in KM) ...... 258 loss of GM as a result of a rise in G (increase in KG).. . .. 257 loss 01 stability when dry-docking .. . .... 257 lost buoyancy (constant rusptacement) method.. .. ......... 266

M Maintenance.... .. ..... .. 325 Maximum cargo to load in each space for a desired trim .... 239 Maximum cargo to load to complete at the

maximum draught. .. Metacentric diagram, producing .. Metaceotric diagams .... Metacontric height (GM) ... . Metacenbic radius. , Method 10 use for bilging caculaHons .. Method to verify complianCe with the regulations .. Me1hods adopted to minimise a shlp's rolling

motion at sea . . Methods of improving ro-ro ship stability .. Midshlps area coefficient (CM)... . ......... .... . Minimum IMO stability criteria for Ships carrying

..... 237 .. 84

. .. 84 . .. ....... 53

... 62 .270

. ... 300

. ... .... 314 .. ...... 343

. .. 18

timber deck cargoes. . . .... 368 Minimum intact stability criterta for cargo ships.. . . ... . 139 Minimum intact stability criteria for passenger ships . .. .. ...... 145 Moment of inenia. .. ................. ... 283 Moment of inertia (second moment of area) of the

water-plane area.. .. .... . 63 Moment of statical stabifity (righting moment}.. . .. 51 Moment to change trim by one centimetre (MeTC) ... ... ... .. 107 Moments of Inertia of rectangular water plane areas.. . ...... 283 r/Ioulded depth.. . .. 347 Multiple weight problems.. . .. ,.44,95,96. 115

N Neutral condition. .. . ... . 59 Non-COhesrve bulk cargoes having an angle

of repose from 30" to 350 . . ... 187 Non-cohesive bulk cargoes having an angle

of repose greater than 35°.. . ...... .... 188 Non-cohesive bulk cargoeS having an angle

of repose less than Of equal to 30".. .. . .. ....... . ..... 18S

o Offshore supply vessels ... . Optional stability requirements to be met by

ships without documents of authorisation canying partial cargoes of bulk grain ..

Overstowing arrangements .. ..

p

. .......... 318.

. . .... .... 209 .... 204

P force calculations , .. 256 P force. requfremenl10 imlt. ........... 261 Parallel axes theorem.. . . . .... 284 Parametric resonance.. ..150 Passenger Ship stability in the damaged oonditlon .... .... .... 337 Passenger ship subdivision and damaged stability

requirements .. Passive stabilising tanks .. . Penneability less than 100% ... Permeability, calculating for a compartment. ..

ClASS 2/1 STABILITY - Index

... 330 .. ... ..... 314

.. ... 274 . .. 275

Penneability. cnd compartment 100%.. .. .......... 279 Perpendiculars (FP, AP).. . .... 347 Pitching. changes in stability .. .. .. .. 150 Practical considerations during dry·docIting. .. . ............ 261 Principles of bilging to be applied to calculations.. . .. ... ..... 290 Procedure for oonstructing the curve of statics! stability ....... 85 Producing a metacentric diagram.. ..64 Producing the curve of bending moments .. . .. 375 Producing the curve 0( loads ... 373 Producing the curve of shear forces..... . ... .... 374

R Radius of gyration. .. . .... .. ..... 308 Recommended general criteria fOl" cargo ships (IMO) .. , ... .. 139 Relative density ... . .... . 11 Reserve buoyancy.. ...13,29,184.319, 320.321.345,

352. 361 , 362, 363, 366, 369 Resisted rolling in stili water. , .. Righting lever (GZ) .. Righting moment .. Rolling in waves .. Rolling, changes in stability ,. Ro-ro passenger ships ..

5

. ... ...... .. 310 .. ....... 49

. .. 51 . .. 311

.. ......... 150 ...341

Saucers.. .. .. .. ...... 202 Sea wave bending.. . .. .. ... . 380 Securing with wire mesh.. ..206 Severe wind and rolling criterion (weather criterion) (I MO) .. 302 Shearforces ........ .. ..... 329, 371 . 372, 373, 374, 375, 381,382 Shear forces and bending moments in still water conditions.372 Shear forces and bending moments in ships... . ..... .. ..... 371 Shear forces curve. producing .. . ........ 374 Shift of grain.. ..196 Shift of grain cargo.. .. ..... 190 Shift, soUd buI'k cargo.. . .......... . ..... 188 Shifting a weight already on board to bring a

listed ship upright. . .. . .... 94 Ship conversion - practical application of increaSing

effactive beam .. ..183 Ship displacement . . . ........... ....... . ....... 81 Ship rolling in waves .. .. . ... ....... ... .... 312

.. .. . .... .. . 1 t 1 .. .. 112

Ship with LCF amidships .. Ship with LCF not amidships .. Ship's side markings .. . .... ... ..... .. ... 349 Simple box-shaped vessel calculations. Simple SF/BM diagrams for box-shaped vessels .. Simplified grain data .. Simplified grain data, presenlation . ... Simplified stability data for ships carrying grain .. Simpson's first rule ..

.. ....... 14 ..373 ..212

. .. ........ 211

Sfmpson's rules for calculating areas under curves .. Slmpson's second rule ..

.. .. 211 .. 132

...... .. 132 .. 134

............ 133 .. 134 .... 41

Simpsons first rule ... Simpsons second rule ... Single weight problems .. So&as amendments, OecerTtler 2002 .. . . . ... .... 329 Special structural conditions of aSSignment for

type '01' ships , ... 357 Stabiliser tanks .. ,.. . ...... .. 322 Stability at large angles of heeL.. . . .. ....... .. ..... 162 Stability at small angles of h~ (initial stability). .. . ......... 162 Stabirrty concems.. ..323 Stability information to be prOvided to the master .. ..... .. .... 216 Stability loss 00 a wave crest. . . ........ 150 Stability problems associated with specifiC ship types.. ..317 Stability problems associated with the design

and operation of rD'ro passenger ships .. Statical stability at small angles of heel .. Steady turning circle radius Steady 'NInd rnom8f1ts .. .. Stiff ships. SUII water' rolling .. .. Stowage requirements .. Strapping Of lashing. ,

.. .. ....... .. 341 .. 54

... ...... . .292 .. 150

.87 .. ....... 307

..366 ... 205

Stress calculating programs - system requiremems and data representation.. ...381

Stress loading programme representations.. . ... ... ...... " .... _381

407

Structural oonditions of assignment.. Structural strength .. Subdivision load lines for passenger ships .. SubdMslon. general approaches .. Subdivision. probabiltslic approach .. Supers1ruct.ure .. Suspended weights . Synctlronism ..

T Tabular freeboard for type 'b' ships under

100 metres in length . . Tabular freeboard type 'b' ships having

...... .. 351 ..... .. 351

... 336 . ... .. 330

. .. 330 ..348

..... .. 121 .... 312

.. . 365

wooden hatch covers .......... ... ...... . .. 365 Tabular freeboard, obtaining . .. . . ..... . 361 Tactical diameter. . . ......... .. . " . . . . .. ..292 Tank breadth.. . .... 77 Tank length. . . ........ 81 Tank sounding sheet. . . ..................... ... ..... .... 384 Tender ships.. . . .. 87 Terms relating to a ship's tumlng circle.. . ... 292 Terms relating to ship length... . ... 102 The effect of loading and discharging weights .......... .... ... 113 Timber deck cargoes, minimum stability criteria .. . ...... 369 Timber freeboards.. . ..366 Timber free boards, special construction requirements . .... ... 366 Tonnes per centimetre immersion (TPC) . . . ... . 21 TPC fOrTnlia.. . ... .23 Transfer.. . .. 292 Transverse statical stability.. . .... 48 Trim.. ..104 Trim calculations using hydrostatic data. . . .. . .. 223, 228, 231 TrilTllllng level the bulk cargo surface ... 188 True mean dral9lt... .... 224 True mean draught. .. . . .. 225 True mean draught when LCF Is amidships .. . . .. . 224 True mean draught when LCF is not amidships .. . ..... 224 Turning, angle of heeL.. ..295 Type 'a' Ship - defiflitic:x1.. . .. 354 Type's' ships and their additional conditions of assignment.354 Type 'a' freeboard, calculation procedures ... . . .. 361 Type 'b' freeboard, cak.:l.Aatlon procedures ... . . ... 365

ClASS 211 STABILITY - Index

U Unrellability 01 using statical stability data

for assessing ship's stablNty at sea ... Unrestricted rolWng in still water ..

W

. .. 149 ..307

Wail-sided formula . ... . .... . 161 Watertight flat. . . .. 271 . 272, 273, 281 . 282 , 290 Wave theory ..... ....... ....... • ..... 311 Weathertight.. ... 348 Weight to load to bring a ship to an even keel.. . ... 118 Weight to load to reduce draught.. . ... 244 Weight to shift to reduce the trim by a specifted amount. .... 117 Weight to transfer to reduce draught. . . .. 119 Wind heeling.. ... ... ..... .... . . ... 298 Wind heeling considerations for all ships .... . . .. 302 Wind heeling coosiderations for container ships.. . ... 298 Wind heeling, k:e acaetion and rolling.. . ........... . ..... 297 Wind Pressure . . ... . .. 302, 303, 339 Wind pressure, units adopted by IMO.. . ... 302

Y yaw .... .. ............... . .... 292

408

-