basic naval architecture

BASIC NAVAL ARCHITECTURE

by KENNETH C. BARNABY

O.B.:E., D.Sc., A.C.G.I.

An Honorary VlCt-President of the Royallnstituzion of Naval ArclUttcls

Frouae MeJallist Parsons Mulallist

Author of Institution of Naval Architects 1860-1960 CAllen and Unwu.) Author of 100 Years of Specialized Shipbuilding and Engineering CHurclUnson)

Warsash Nautical Bookshop

CONTENTS

EXTRACT FROM PREFACE TO FIRST EDITION Page '3 PREFACE TO FIFTH EDITION 13

I. INTRODUCTORY IS

I. Ship Terms. IS 2. Symbols and Notation. 15 3. Order of Presentation. 16 4. Dimensions and Rules. 16 5. Appearance. 17

11. HULL FORM-DELINEATION AND GEOMETRY

6. Definitions. 7. Lines Drawing and F airing the Lines 8. Conic and Cylindrical Development 9. Sheer Line.

tII. THE CALCULATION OF AREAS, MOMENTS, ETC.

10. Mensuration Rules. II. T rapezoidal and Mean Ordinate Rules. u. Mathematical Basis for the Simpson and Tchebycheff

Rules. 13. Simpson's First Rule. 14. Simpson's Second Rule. IS. "5 + 8 - I" Rule. 16. Durand's Rules. 17. Tchebycheff's Rules. 18. Half Spacing. 19. Effect of "Knuckles" and End Correction. 20. Choice and Accuracv of Rules. n. The Planimeter. . 22. The Integrator. 23. The Integraph. 24. The Calculation of First Moments and Moments of

Inertia. 25. "3 + 10 - I" Rule for Moments. 26. Radial or "Polar" Integration.

IV. FLUIDS AT REST-FIRST PRINCIPLES

27. Pressure Head. 28. The Density of Sea Water.

19 19 28 29 32

34 34 35

36 37 38 39 40

41 43 43 44 4S 46 48

49 53 53

S6 ~6

57 3

CONTENTS

2.9. Total Pressure and Centre of Pressure. 30. Calculation of the Centre of Pressure. 31• Centre of Pressure on Inclined Plane. p. Floating Structures-Principle of Archimedes. 33. Buoyancy, Pressure and Volume.

V. TRANSVERSE STABILITY

34. The Metacentre and Axes of Inclination. 35. Heeling and Righting Moments. 36. Initial Stability and Metacentric Height. 37. Free Surface. 38. Inclining Experiment. 39. Stability at Large Angles. 40. Layer Correction. 41• Barnes' Method for Stability. 42. Stability by Integrator. 43. Cross Curves of Stability. 44. Alternative Methods for Transverse Stability. 45. Dynamical Stability.

VI. TRIM, LONGITUDINAL STABILITY AND ADDITION OF

WEIGHTS, ETC.

46. Principal Axes of Inclination. 47. Trim and Trimming Moments. 48. Longitudinal Metacentre. 49. Moment to Change Trim One Inch. 50. Formula for Moment to Change Trim One Inch. SI. The Addition of Weights. )2.. Suspended Weights. 53. Movable Weights. 54. Stability when Grounding or Docking. 55. The Stability of Submarines.

VII. HYDROSTATIC CURVES AND THE DISPLACEMENT

SHEET

56. Displacement Calculation. 57. Vertical Centre of Buoyancy (V.C.B.). 58. Longitudinal Centre of Buoyancy CL.C.B.). 59. Tons Per Inch (T.P.I.). 60. Transverse Metacentre from Sheet.

r CONTENTS

61. Longitudinal Metacentre from Sheet and Centre of Flotation. 101

62. Moment to Change Trim One Inch from Sheet. 103

63. Change of Displacement for One Foot Change of Trim at Perpendiculars. 103

64. The Plotting of Hydrostatic Curves. 103

6j. Morrish Formula. IOj

66 . . Bonjean Curves. 10j

67. Wetted Surface by Measurement. 107

68. Wetted Surface by Formula. 107

69. Wetted Surface of Abnormally Shallow-Draught Forms. 108

VIlI. RULES FOR FREEBOARD, SUBDIVISION AND

STABILITY 109

70. National and International Regulations. IC)9

71. Load Line Markings. 109

72. Minimum Summer Freeboard. 110 73. Standard Sheer :md Sheer Difference Correction. 112

74. Round of Beam Correction. 113 7j. Nomenclature and Dimensions, etc., in F reeboard

and Subdivision Rules. 113 76. The Criterion of Service Numeral (C,). 116 77. Factor of Subdivision. 117 78. Use of Standard Floodable Length Curve. 119 79. Correction of Standard Curves. 120

80. Modifications for Restricted Plying Limits. 120

81. Permeability Interpolation Formula. 122

82. Basic Principles and Equations for Floodable Length Curves. 122

83. Explanation of Form Corrections to Floodable Length Curves. 125

84. Special Rules concerning Subdivision. 127

85. Added Weight Method for Flooded Stability. 128

86. Lost Buoyancy Method for Flooded Stability. 129 87. Flooded Metacentric Height and Angle of Heel. '30 88. Intact Buoyancy and Angle of Heel. 131

89. Stability Requirements. 132

IX. FLUIDS IN MOTION-FIRST ·PRINCIPLIi:S 135

90. Currents and Streams. 13S 91. Dimensions of Measurement Units. 135

!

CONTENTS

92. Total Energy of Water. 93. Bernoulli's Steady Motion Theorem. 94. Limitations of Bernoulli's Theorem. 9j. Venturi Tube and Meter. 96. Venturi Effect with Ships in Restricted Waterways. 97. Magnus Effect and "Circulation" 98. Pitot Tube. 99. Streamline Flow around Vessel in Open Water.

100. Impact of Water.

X. FLUIDS IN MOTION--GRAVITY AND VISCOSITY

EFFECTS

101. Real Fluids. 102. Viscosity. 103. Effect of Temperature on Viscosity. 104. Kinematic Viscosity. 10j. Comparison with Air. 106. Pressure Conditions on Inclined Flat Plate. 107. Flow Pattern at Inclined Flat Plate. 108. Formulae for Pressures on Plates Inclined at Various

Angles. 109. Eddy-making Resistance from Blunt-Ended Fittings. 110. Laws of Dimensional Similarity and Comparison. lIt. Reynolds Number and Viscous Resistance. 112. Froude Number and Speed/Length Ratio. 113. Combined Viscosity and Gravity Resistance. 114. Froude's Method and Law of Comparison. 115. The Validity of Froude's Assumptions. 116. Presentation of Form and Resistance Data-

Froude's Constants. 117. American Notation for Resistance Data. 118. The Admiralty Constant and "Circular C" 119. Reynolds Number for Propellers and Sails

XI. THE PROPERTIES OF WAVES

6

120. Types of Waves-Pressure Waves. 12t. Ripples or "Capillary Waves". 122. Waves of Oscillation-the Trochoidal Theory in

Deep Water. 123. Dimensions of Actual Ocean Waves. 124. Group Velocity of Wave Trains. 125. Shallow-Water Waves and Waves of Translation.

- - - ---------------

CONTENTS

XII. SURFACE FRICTION

u6. Froude's Experiments. 187

1~7. Reynolds' Experiments. 189

128. Gebers' Experiments. 190 u9. Laminar and Transitional Flow. 192

130. Boundary Layer Flow Conditions. 193

131. "Smooth-Turbulent" Friction Lines. 195

Ip. Boundary Layer Thickness. 201

lB. Effect of Rough Surfaces. 201

134. Comparison of Froude's Constants with Modem Formulations. 204

135. Calculation of Frictional Resistance and Horse-power. 205

136. Temperature Correction for Surface Friction. 206

137. Effect of Fouling. 206

138. Form Effect. 207

139. Frictional Wake. 208

140. Summary of Friction Calculations. 209

XII!. RESIDUAL RESISTANCE AND FORM 211

141. Wave Causation. 211

142. Growth of Wave-Making Resistance. 212

143. Spacing of Wave Systems. 214 144. Residuary Resistance from Standard Series Tests. 217

145. Summary of Taylor Results. _ 218

146. Modem Improved Forms-General Considerations. 2~2 147. Midship Section Coefficient and Area. 223

148. Parallel Middle Body and Length of Entry. 224

149. Angle of Entrance. 225 150. Curve of Transverse Areas. 226

'51. Maier-Form Bow. 227 152. Bulbous Bows and "Waveless" Forms 228

'53. Residuary Resistance of Destroyer Types. 229

154. Residuary Resistance of Motor Launches. 229

155. Residuary Resistance of Fast Round-Bottom Launches. 230

XIV. EXPERIMENTAL TESTING TANKS OR "MODEL BASINS" 232

156. Types and Dimensions. 2 J2 157. The Scaling Up of Tank Results. 235

'58. Turbulence Stimulation and Tank "Storms". 238

159. Telfer Method with "Geosims" 240

7

CONTENTS

XV. AIR RESISTANCE AND SAIL PROPULSION 242 ./

160. Comparison of Air and \Vater Resistance. 242 161. True and Relative or "Apparent" Wind. 244 ; 162. Air Resistance of Ships. 24j

i 163. Sail Propulsion. 249 I 164. The "Gimcrack" Sail Coefficients. 212 , 16j. Sail Plans. 2j6 ! 166. Centre of Effort and "Lead". 2j7 167. Resistance and Balance of Sailing Vessels. 2j9

!.

I 168. Sail Area and Power to Carry Sail. 261 169. Multi-hulled Vessels. 262

XVI. MARINE PROPELLERS 26j

170. Jet Propulsion and Fluid Efficiency. 26j I

171. Apparent and Real Slip. 268 I.

172. Wake Factors and Wake Percentage. 269 i 173. Paddle Wheels. 270 174. Volpich and Bridge Method of Paddle Wheel Design. 272 17j. Stem Wheels. 274 176. Fixed and Feathering Floats. 27j 177. Screw Propellers-Theories and Methods of Design. 277 178. Propeller Notation and Constants. 278 179. Propellers and the Law of Similarity. 28j 180. Interaction of Hull and Propeller. 181. Variation of Hull Efficiency, Thrust Deduction and

287

Wake. 289 182. The Calculation of Thrust Loads and Bollard Pull 292 183. Kort Nozzles. 298 184. Lateral Thrust Units. 299 18j. Blade Area and Number of Blades. 301 186. Cavitation and High Thrust Loading. 303 187. Fully Cavitating Propellers. 308 188. Examples of Propeller Design. 3II 189. Handing of Propellers. 312

19Q. Strength, Thickness and Materials of Propeller Blades. 313 191. Circulation or Vortex Theory. 31j

XVII. THE POWERING OF VESSELS 320

192. Powering Methods. 320 193. Propulsive Efficiency. 323 194. The Admiralty Constant. 325 195. Direct Power Curves. 327

8

CONTENTS

196. The "K" Method of Pow~ring. 32.S 197. Tow-rope Horse Power for Dumb Barges, etc. 330 I9S, Shallow Water Resistance. 331

XVIlI. THE DESIGN AND POWERING OF PLANING CRAFT 336

199. The Planing Principle. 336 200. Measurement Coefficients for Planing Hulls. 339 201. Lift and Centre of Pressure. . 340 202. The V.S.T.M.B. Series 62 Tests. 345 203. The Powering of Hard Chine Stepless Hulls. 347 204. Stepped Hulls. 349 20S. The Hydrofoil Boat. 351

XIX. MOTION IN A SEAWAY 356 206. Types of Motion. 356 207. Forces Due to Rolling and Pitching. 360 20S. Period of Encounter and Forced Rolling and Pitching. 361 209. Relation of Period of Encounter to Natural Period. 362 210. Steering and Manreuvring. 364 2II. Turning Circles. 364 212. Rudder Areas and Pressures. 366 213. Balanced Rudders, Strength of Rudders, etc. 369 214. Heel when Turning. 371 21 5. Steering by Propellers. 372. 216. Fletmer, Kitchen and Tutin Rudders. 373 217. Summary of Steering and Course-Keeping. 374 2IS. Anti-Rolling Devices. 375 2. I 9. Seaworthiness and Proportions. 380 220. The Starting and Acceleration of Ships. 3SI 2.21. Stopping, Astern Way and Propeller Drag. 384

XX. THE STRENGTH OF SHIPS 388

:122. Classification Rules. 223. Beam Theory, Bending and Shear Stresses, De/lec-

388

tions, ete. 390 224. Direct Detennination of Bending MomenL 393 225. Standard Approximation for Bending Moment. 397 226. Still Water and Wave Bending Moments. 398 227. Stress and Modulus Calculations. 401 228. Working Stresses. 402 229. LocaI!Strength. 403

9

..

CONTENTS

230. Measurement of Static Stresses, Strains and Deflec-tions. 404

231. Dynamic Stresses. 406 2)2. Expansion Joints. 407 233. Composite Construction. 407

XXI. THE VIBRATION OF SHIPS 409 234. Modes of Vibration for Uniform Bar. 409 235. The Vertical Vibration of Ships. 410 236. The Horizontal Vibration of Ships. 421 237. Precautions against Vibration. 423

XXII. LAUNCHING CALCULATIONS 425 238. General Principles. 42; 239. Launching Curves. 426 240. Way-End Pressures. .p8 A 241. Launching Particulars. 430

E 242. Releasing Arrangements and Coefficient of Friction. 434 243. Dynamic Effects. 436 I 244. Broadside Launching. 437 245. Marine Railways. 438 I

XXII!. MATERIALS OF CONSTRUCTION 439 246. Wood v. Steel. 439 I 247. Structure and Growth of Timber. 440

I 24&. Annual Growth rungs. 440 249. Maturing, Seasoning and Moisture Content. 442 1 250. Time of Felling and Methods of Conversion. 443 251. Qualities Required for Shipbuilding Timbers. 444 .1 2P.. Plywoods and Laminated Construction. 444 253. Qualities of Individual Woods. 445 254. Plastic Hulls. 451 255. Steels. 453 256. Aluminium Alloys. 453 257. Galvanic Corrosion. 454 258. Precautions against Galvanic Corrosion. 460 259. Local Corrosion. 462

XXIV. SOME DESIGN PROBLEMS 465 260. Tonnage Regulations. 465 261. Weight Estimates. 468 262. Special Types. 470 263. Computers. 473

10

...

?

L

264. Ram bows APPENDIX

CONTENTS

265. Polar Moment of Inertia of Propeller. 266. Calculation of Propeller Suesses.

NUMBERS AND CONVERSION FACTORS

SAME INDEX

SUBJECT INDEX AND GLOSSARY

LIST OF ABBREVIATIONS

A.T.T.C.-American Towing Tank Conference.

B.S.R.A.-The British Ship Research Association.

D.T.M.B.-David Taylor Model Basin.

493

495

499

I.E.S.S.-Transactions of the Institution of Engineers and Shipbuilders in Scotland.

LN.A.-Transactions of the Royal Institution of Naval Architects.

I.T.T.C.-International Towing Tank Conference.

N.A.C.A.-National Advisory Committee for Aeronautics, U.S.A.

N.E.C.-Transactions of the North-East Coast Institution of Engineers and Shipbuilders.

N.P.L.-The National Physical Laboratory, Teddington and Feltham.

S.N.A.M.E.-Transactions of the Society of Naval Architects and Marine Engineers.

U.S.N.-United States Navy.

11

r

SUBJECT INDEX AND GLOSSARY Tire numbers refit to pages, MC articles

Acceleration (definition), 'J7(d) Acceleration of Ships, 381 Added weight method for stability, 1>8 Addition of weights, 9' Admiralty constant, 171, 325 Advance, )65 --, speed of, 269 Air coefficients, 155"

-- data, 'J8(h) -- resistance of ships, 2.45 Alexander fonnula for block coefficient,

222 Aluminium alloys, 407, 452, 453-00 Angle of entrance, 19, Table 24, 2.,1.5 Angular velocity, 'J7« ) Annual rings, 440 Anode, Figs. 132, 133, 451-463 Anti.fouling, z06 -- rolling devices, 375-80 Apparent slip, 268 --wind,244 Appearance, 17 Apron (a shaped piece of timher ahaft the

stem), ]5 Arc.form, 224

Archimedes, Principle of, 62 Ard.ncy, 2)7, Fig. 88 Areas, Curve of, .2.1 , %16

Ash, 440, 44 5 Aspect ratio, 19, Fig. cJ4, I Go Atmosphere, Standard, 1J8 Attwood's formula for stability, 67, 74 Autumn wood, 441, Fig. 129 Axes of inclination, 66, 86

Balsa wood, 440, 44 5 Barge form, HO Barn .. ' method, 75-80 Beam theory, )90

Bearing pressure (launching), 430, Fig. 1>4

Beating (sailing to windward), '49 Beaufort Scale, Fig. 67, 184, Table 17,

'4) Beaufoy's formula (rudders), 161, J68 Beech, 446 Belly (sails), >56 Bending moments, 393-402 Benjamin's method (stability), 84 Bernoulli's theorem, 141-5 Bias correctOr, 3 I 3, 374 Bilge diagonals, • 9 -- keel, '9, J76 Binary notation, 474 Birch, 446 Blasius formula, Fig. 69, 192 Block coefficient, 19, 1I4, 222 Blockage, 2)4

Blom method (stability), 84 HB.M." (meracentric radius), 66 Body plan, 20 Bollard pull, 292-8, Tables J>, JJ Bonjean curves, 105

Bonnet (additional canvas below the foOL of a. soil), 1$

Bossing, 20, 290

Boundary layer, Fig. 6., '58 ---- thickness, '9J Bow lines, 20

Boxing the hean, Fig. 1)0,443 Breadth for freeboard, 113 Broad reach (sailing wit" the wind ohaft the

beam, NtwUn. running and reading}1

249 Broadside launching, 4J7 Budget plate (see under Deadwood),

2I

Bulbous bows, 228, 475 Bulk modulus, '44

499

---------- - - - -

I !


Buoyancy, 63, 100, 131

Burbling, 158 Butt (of timber), 440 Buttocks, 2.0

cO ("circular c"), 170 Camber, 2.0

Cambered ways, 4),2., Fig. 127 Cambium, 440, 442 Camels, 6z Camphor wood, 446 Canal barges, 330 Cant frames, 20

Capillary waves, 173 Cascade effect, 278 Catamarans, 263 Cat-harpings (small ropes hunching up tlte

lee shrouds), 15 Cathode, Figs. 132, 133 Cathodic protection, 455-463 Cavitation, 286, 303-3 I I -- number, 286 -- tunnel, z87, 304 Cedar, 446 Centre of buoyancy, 21, 62, 66, 100-1

----- effort, 257 ----- flotation, 86--8 101, 124 ----- lateral resistance, 258 ---- pressure, ;7, 59, 61 Centrifugal force, 14o(n) Change of trim, 87, 103, 1.24 Channel steamers, 226, P·7, 360 Checking (launching), 436 Chine, 21, 336 Circular constants, 169 --measure, 177 Circulation, 147,315 Classification rules, 385 Clinker, or clencher built (hoathuilding

with overlapped strakes in lieu of flush carve! planks), 448

Coefficient of friction (launching), 434 ---- reduction (rudders), 368 -- --- resistance, 170(c) ---- roughness, 201

----- surface friction, 187 Columbian Pine (su under Oregon Pine)

500

Comparison, Law of-Froude's, 166 ------ -Propellers, Table 31,

280, 286 ------ -Viscosity, 164 Composite construction, 407 Computer usmoothing", 474 Computers, 473 Cone propeller, 140 Conic development, 29 Contra-propeller, 2.78, 374 Conversion factors--Qil, Table 5, 58 ---- -water, Table 4, 58 Conversion of lumber, 443 Copper sheaclllng, 460 Corrosion, 454 Course keeping, 374 Creep resistance (launching), 434 Criterion of service, 116

Critical velocity of water, 189 Cross curves of stability, 81 Cruiser stern, 227 Currents (hydrodynamic), 135 Cut-up, 21

Cylindrical development"29 Cypress, 446

Damping coefficients, Table 48, 375 Datum planes, 21

Deadrise, 2], 338 Dead'N'ater, 173 Deadwood, l.I -- in timber, 442 Decremental equation, 375 Deducted spaces, 465 Deflection of beams, 390 Denny-Bro'WIl Stabiliser, Fig. 119, 378 -- Mumford formula (wetted surface),

108 Density, 15, 57, 1)8 Denudation of floats, 162. Depth for freeboard, 113(e) Depth and fullness, corrections for, I I I

Design data, Table 58, 4<>9 Destroyers, Admiralty constants, Table 39,

327 --, propulsive efficiency, 2.29, 324 --, residuary resistance, Table 25, 2.29 De-zincification, 460

•


Diagonals, 22

Dimensional similarity, 163 Dimensions and rules, 16 -- of measurement units, 135-40 Dipping, 316 Displacement calculations and Sheet, 22,

Table 10,9<>-100

Displacement ratio, 170, 2.18

Docking stability, 93 Dog,hores, 425, 434 Douglas nr, «I')

Drag coefficient, 157, .lp, Fig. 119, 379

-- induced, 242

-- profile, 242

Drags (launching), 436 Draught for freeboard, 1I4(J) Draught marks, :12, 62 Dry rot, 442 Durand's Rules, 40 Dynamic .tfects (launching), 436 -- pressure, 242

-- stresses, 406 Dynamical simiiaricy, J 64 -- stability, 68, 84

----, Torquay, 187, 232 Extrapolator, Telfer's, 199

Factor of subdivision, 117

F airings, 22

Feathering paddles, 271 Felling (of trees), 443 Ferries, 471 Fetch (of waves), 180 Fibre-glass, 41 I

Fir, 449 First moments, 49 "Five-eight-one rule", 39 Fixed floats, 1.75 Flare, .z..t

Flettner rudder, 373 Floating docks, 473 FloodabJe length, 116, 119 Flooded stability, 128 Flow pattern and coefficients, 157 Fluid efficiency, 265 Force (definition), 138 (g) Farm effect, 207 Fouling, %06 Free surface, 69, 1)2, 211

Eddy making, 161, 22l ---- correction, 71 Electra-chemical series, 455 Freeboard (definition), 2l

Elecuolysis,455 -- markings, 109 Elm, 446 -- ratio, 115

Encounter, period of, 361 -- rules, 110-4 End correction (mensuration), 43 -- standard, 110

Energy of water, 140 Friction drag, Table 3, 56 ---- waves, 179 --launching, 434 Entrance, 22, 22.4 --lines, Table 19, 195-210, Table -- angle, 19, 225 66,489 Epochal hull fonn, 228 Friction horse-power, 205 HE.T.T. formula" (planing hulls), 342 -- summary, 209

Exempted spaces, 465 --, surface, I87-:z.z0 Expansion joints, 40'7 --, temperature correction, 206 Experimental tanks, 232 --, wake, %08 -----, Carderock, 232 Froude number, 165 -- --, Clydebank, :l40 Froude's assumptions, validity, of 168 -- ---, Fort Steyne, 232, 349 -- constants (frictional), Table 17, 187, -- ---, Haslar, 188,239 Table 18, 188 -----, Stevens,· 232, 252,341 ---- (non-dimensional), 169 -- --, St. Albans, "3 -- formula (rudder), 16!

·Now [enned the "Davidson Laboratory, Stevens Institute" IO!

-


Froude's assumptions (wetted surface), 108

-- Jaw of comparison, 166

Gaboon,447 Galvanic corrosion, 454 Gebers' experiments, 190 Geosims (Telfer method), .40 Gimcrack coefficients, Table, :loS, 252 Glass fibre, 451 ,cG.M." (transyerse metaceraric heigh.t), 66-

95, 132,380-1 Gradient wind, 182.,254 Greenheart, 447 Gyroscopic stabiliser, 378 "G.Z." (righting lever), 6"-95

Half spacing, 43 Hard chine hulls, 336-351 Hardwoods, 440 Heartwood, 442. Heaving period, 357 Heel when turning, 341, 371 -- (wind pressure), 261 Heeling angle and moment, 67, 130, 26 I Hele-Shaw method (streamlines), 150 Hogging stresses, 394 Hooke's law, 390 Hoop effect, 2.48, 254 Horse (bar or rail on wmch. a sh..eet travels),

15 Hounds (mast projections carrying shroud

attacltments), 15 Hull efficiency, .87 Hydraulic gradient, 189 -- propulsion, 265, 300 -- smoothness, 202 "Hydrofin" (Hook type), 353 Hydrofoil boat, The, 351 Hydrog.p rudder, 367 Hydrostatic curves, 103 -- pressure, 56-65

Impact of water, 152 Impulse (definition), 138(()

502

Inclining experiment, 71 Inertia and moments of inertia, 139 Inflow of water, J41

Inside multipliers (mensuration), J4 Intact buoyancy, 129 Integraph, 48 Integrator, 46, 80 Interaction, hull and propeller, 2.87 Inrerpolation fonnula (permeability), 121 ----- (subdivision), lIS !rOkO,447 "Iron bacteria", 464 "LT.T.e. formulaH

, Table 19,200, Table 66,489

''1'' (propeller constant), 280 "J~class" yacht, 225, Table 29, loGo-I Jarrah,448 Jet propulsion, 265 Joesse]'s formula (rudder), 161

® (speed constant), 169(6) "K" method of powering, 32.8, Table 40,

Fig. IIZ, 347 Karri,448 Kauri,448 Kinematic viscosity, 155, Table 14, 156 Kinetic energy, 139(/) Kimen-Boeing propeller, 373 Kitchen rudder, 373 Knot, 137(6) Knuckle, 2.), 43 Kort nozzle, 298

© (speed conStant), 169(6) Laminar film (or sub-layer), 2.02. -- flow, 189, 192 Laminated construction, 444 Larch, 441, 448 Late wood, Fig. [29, 440 Lateral resistance, centre of, 2.~7 -- thrust units, 299 Launching calculations, 402 Layer correction, 73, Fig. 28 "Lead" (sails), Fig. 88, 2\7

--- --- --- .--------------------------~--

•

Lead keel, 460 Lee helm, 257 Leeboards, ~61 Leech (or leach), 256 Leeway, 2.52


HMetacentricshelf" , 1.58, lOO Midship section coefficient, 2.3,.:11.3 Mill scale, 46,

Length for freoboard rules, I13(a) Lift, 157, lSe , Fig. 98, 305, Fig. 106,

337, Fig . 108, 342, Fig. 113, 3P. Lignum vitae, 448 Lines plan, 23, Fig. 0, 27, 28 List, 86, 131 Lizard Ca sh.or: length of rope with an eye at

one end), 15" Load Line, 110

Loblolly pine, 450 Local corrosion, 4(52 -- strength, 403 Locked.up stress, 403 Longitudinal centre of buoyancy, 89, 100

-- metacentrc, 89, 101

-- modulus, 40 1

-- stability, 86-95 Lost buoyancy method, 129

Lundberg method (effective depth), 4t3

® (length coefficient), t69(a) Magnesium, 461 Magnus effect, 147, 168 Mahogany, 448 Maier bow, Z27, 238 Manganese bronze, 314, 460 Manceuvring with twin screws, 371. Margin line, 114 Marine railways, 438 Mass (definition), t35 -- correction factor, 414 -- density, 136, t38(.I) Materials of construction, 439 Maturing, 442 Mean ordinate method, 35, 102

-- width ratio, 301

Measurement units, I) 5 Mechanical efficiency, 32) Medullary rays, 444 Mensuration rules, 34-44 Metacentre, longitudinal, 89, 91 --, transverse, 66, 68-85

Mineral grease, 431 Mixing length, t 96 ~·fodel basins (see Experimental tanks) Modulus factor, Table 50,394 Moisture content, 442. Moment against tipping, 42.6 -- of inertia, 49, 139, 476, Fig. 135 -- to change trim, 90, 91, 103 Momentum, I38(e) Monel metal, 460 Moorsom system, 465 Morrish formula for V.C.B., 10S Motion in a seaway, 356-387 Motor launches, Z2.9, 327 -- sailer, zoo, 471 Moulded dimensions, l. 3 Movable weights, 9Z Multi-hulled vessels, .6, Munion (division berwun stern lights), 15

Nautical mile, t 36(C), t )7(b) Nonnand formula for M.C.T.t·, 9' Notation, dimensional, 135 --, general, 1 5 --, Propellers, 2.78

"0", Froude friction constant, 238 Oak, 44), 449 Obeche,449 Ocean waves, 174-84 Offsets, 23 Optimum efficiency (form), .>I(d) Ordinate stations, 14 Oregon pine, 441, 449 Outside multipliers (mensuration), 34

®, 169(.) >15 Paddle wheels, ,68, '70-4 Paints, 204, 46z Panama Canal rules, 468 Parabolas, 36-4Z ·"

Parallel middle body, '4, "4 50 3


"Park Avenue" boom, 2.57 Perfect fluid, 5G, 144, 154 Permeability, IIG(m) -- formula, l ,n

Peroba, 450 Perpendiculars, 1.4 Phantom ship, 187 Phosphor bronze, 460 Pitching forces, 360 -- periods, 357 Pitch-pine, 408, 450 Pi tot tube, 149 Planimeter, -45 Planing coefficients, H9 -- forms, 33G Plastic hulls, 451 Plying limits, 1;2.0

Plywood, 444 Polar Moment of inertia, Fig. J35, 476 Polyester resin, 45 I Pomiglion (a knoh on tlu ",J of a gun), '5 Pooping, .11 5 Popoffka, 17 Porpoising, 338, 346 Position head, 140

Poundal, 13G Power (definition), 139(j) -- to carry sail, 261

Powering curves, 327, Fig. 104, Figs. 137-9,490-2

-- methods, 320, 32.8 Pressure, absolute, 57 -- gradient, 65 -- head, 56--65 __ on inclined plane, 6 I ---- plate, J 56 -- -volume relation, 63 Pressure W3ves, 173 Prismatic coefficien~ .14,173,216 Pro-meucentre, 69 Propeller area and number of blades, 301

__ , constants, 1.80, Table 30, :2.81, Tables 6'-5,484

-- design, 1.77, j I 1 -- drag, 384 -- ducted, 1.99 -- frequency, 4'3 -- handing, 1.78, 311.

50 4

-- inertia, Fig. 13 S, 476 -- materials, ; J;, 460 -- pitch, 1.68, 179 -- strength, 3'3 -- stresses, 478 -- super.cavitating, 308 -- theories, 277 Propulsive efficiency, ;23

Quarter wheels, 1.74 Quasi-propulsive efficiency, 31.0, 323

Radial integration, p Radians, '37«) Rake, 25 Rayleigh's formula (eddy resistance), 161 Reaching, 159 Real fluids, 144, 154 -- slip, 268 Redwood, 441, 450 Reech method for Slability, 83 Relation coefficient, %s Relative rotative efficiency, 2.88 -- wind, 144 Residual resisrence, 1702.11.-231 __ --- of destroyer types, 22.9 ____ - hard chine hulls, 340

-- --- - motor launches, 2.29 -- ---, standard series, lI7

Resistance constants, 169 __ of blunt-ended fittings, ,G, --, gravity type, ,G3 --, sailing vessels, 2.59 --, viscous, 163 Restricted 'Waterways, 146 Reynolds' experiments, 189 Reynolds number, 164, 1.42, __ --- for propeller, 172

-- streSSes, t 94, 2.08 Rhine lighters, 330 Righting moment, 67 Ripples, 173 Rivet hole deduction, 401, 405 Rock elm, 447 Rockered keel, 15 Rolling periods, 35G -- forces, 360

T

1-,


Rotor ship, 147 Rough surfaces, 201

Round of beam correction, III Round~up, 25 Rudders, 364-374 Run, 25

® (skin constant), 169(c) Sail area, 256, loGI

-- propulsion, 249 Salinity, 57 Sapwood, 442 Scale effect, u'iS, 240

Scaling-up tank results, 235 Scantling numerals, )88 Schlick constant, 410

Scotchman (an anti-chafe batten), 15 Seasoning timber, 442 Seaworthiness, 17, 380 Second moment, 139 Shallow water resistance, 33 I ---- waves, 186,331 Shear stresses, 390, 40) Sheer, 2.~. Ill.

-- correction, I 12

-- deflection, 393 -- ratio, 116 Ship terms, 15 Shut bevel, >5 Similarity (su Comparison Law) Simpson's First rule, 37, 102

-- Second rule, 38 Singing propellers, J 15 Sink and source, 150 5inkage in fresh water, 62 ---- restricted waterways, 146 Slackness, Fig. 88, 257 Slip, Fig. 91, 268 Slugs, 136 Sluice keel, 22

Smith correction, 40), 406 Snail, Fig. 80, 234 Soft woods, 441 Space (unit), 136(C) Specific gravity, 19,62, 138(h) Speed (definition), 137(4) --/length ratio, 1650 170<.6)

-- of sound in water, 173 Spinnakers, 256 Spring vessels (see unJ" Oak), 449 --WOOd,441 Spruce, 450 Squat, II S, 336 Stabilisers, 375 Stability at large angles, 71. ---- small angles, Fig. 11,66 --, Barnes' method, 75 --, Bcnjamin's method, 83 --, Blom's method, Fig. 33, 84 -- criterion, 381 -- cross curves, 8 I --, direct wedge method, 84 --, docking, 93 --, dynamical, 68, 84 --, flooded, U7-)2 --, Leland's method, 83 --, longitudinal, 8~5 -- of submarines, 94 --, Reech's method, 83 -- requirements, 1)2

--, transverse, 66-~n Stagnation point, Fig. 60, 158 -- pressure, Table 27, 158, Z43 Starting declivity, 433 Static friction, 435 -- pull, 292, Tables )2, 33 Steels, 453 Steering, 364 -- by propellers, 371 Stepped forms, 344 Stern ty~s, 227 -- wheels, 274 "Stonns" in towing tanks, 239 Stream tube, Fig. 50, 14J Streamline (definition), 135 Streamlining, 18, 248 Strength of ships, 388-408 Stresses in a seaway, 402..

Subdivision factor, 117

-- rules, I 13-28 Submarines, stability, 94 Summer £reeboard, 110

Supersonic velocity, 173 Superstructures, corrections for, III

50 5


Surface friction, I87-~ro -- tension ~ 175 --, wetted, t07, JJ7 Surging, 316 Suspended weights, 92 Symbols and notation, 15 Synchronous rolling and pitching, 362.

Tactical diameter, Fig. 116,365 Tallene, 431 Taylor's methodical series, Tables ZI-2,

,16 Tchebycheff's rules, Table " 36,41 Teak, 408, 444, 451 Temperature stress, 404 Thames tonnage , 16 "Three-ten-one" rule (moments), n Thrust deduction factor, 287 -- ho rse-power, 288 -- load and pressure, 291.

Timber conversion, 443 --, qualities of, 444 -- strucrure and growth, 440 Time (unit), 131(A) Timenoguy (pron. "timminoggie"-a rope

secured to the anclwr to keep the jib sheets from fouling 'hejlu/ees), I1

Tip speed, 307 Tipping moment, 427 Tobin bronze, 460 Tonnage openings, !IS, 467 -- regulation~, 465 Tons per inch, 26, 63, 101

Torque, I 39(k) Torsional periods, 414 Toxic layer, 207 Transfer, Fig. 116, 361 Transitional flow, 192

Transmission efficiency, 3:2.4 Trapezoidal rule, 34 Triggers, launching, 434 Trim and trimming moments, 87, 103 Trimarans, 2.63 Trochoidal theory, 174 Troost's propeller constants, 2.8.2., .2.9.2.,

'95, Tables 6t-I, 484-8 True wind, 2.44

106

Tugs, 470 T urnblehome, :.6 Tungum,460 Turbulence stimulation, 238 Turbulent flow, 189 Turning circle, 364 --frame, :2.6 Turin rudder, 373 Tyloses (see untler Oak), 449

Underwater fittings (materials), 460 D.S. T.M.B. Series 6, tests (hard chine

hulls), 341

Velocity (definition), 137(6) -- head, J40

Ventnor hydroplane, 350 Venturi effect, 146 -- meter, 14~ Versine curve, :2..2.6 Vertical prismatic coefficient, 2.6 Vibration, horizontal frequency, 4U --, modes and nodes, 409 --, precautions against, 42.) --, vertical frequency, 409-42.1 Viscosity, 154 --, kinematic, J 5 5 -- of air, 15)

-- resistance, 164 Voith-Schneider propeller, 373 Vortex theory, 147,315 Vortices, 140, I 59 Vosper stabiliser, 378

Wake factor and percentage, l~ --gain, .2.88 -- values, Fig. 96, .2.91 Waterlines, .2.6 Waterplane coefficient, .2.6 Watenight decks, I}>

Wave, capillary, 173 -- causation, 180

--, clapotic, 173 -- energy, 179 -- groups, 181

f SUBJECT INDEX AND GLOSSARY

--lengths, 176, Fig. 67, ]81 -- line curve, ~2.6 -- of oscillation and periods, 174 -- of translation, 186 -- resistance, 1. I J.

-- trochoidal, 174 "Waveless" form, 22.8

Way end pressure, 428 Weather helm, '57 Weight estimates, 468 -- of oil, Table \, 58 -- - water Table, 4, S8 Welding, 403, 413, 463 Western Red Cedar, 446 Wetted surface, 18, 107-8 "Wind and Water", 444

Wind speed, t81

-- tunnels, IS? Wood v. steel, 439 Work (definition), t39(i) Working stresses, 402

Wych elm, 447

Yacht design (motor), 470 Yaw-heel and yawing, 378

Zero circle, 46 Zirnmennan fonnula (wind), 181

Zinc protectors, 4GI

basic naval architecture

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