Movable Bridge Design

Contents Preface xi
Acknowledgements xiii
About the authors xv
About the contributors xvii
Notation xix
1 Introduction 1
Charles Birnstiel
1.1 Need for movable bridges 1
1.2 Basic motions of movable spans 2
1.3 Early movable bridges 5
1.4 Notable 19th-century movable bridges 9
References 21
2 Individual movable span forms 25
Charles Birnstiel
2.0 Introduction 25
2.1 Simple trunnion bascules 25
2.2 Balance beam bascules 27
2.3 Strauss articulated bascule bridges 31
2.4 Rolling bascules (Scherzer) 38
2.5 Swing bridges 45
2.6 Vertical lift bridges 51
References 61
3 Movable spans in series 63
Charles Birnstiel
3.0 Introduction 63
3.1 Symbols and notation 63
3.2 Double-leaf bascule bridges 63
3.3 Mid-span shear locks 69
3.4 Double-leaf trunnion girder bascule bridges 73
3.5 Double-leaf trunnion bascule bridge examples 74
3.6 Double-leaf rolling bascule bridges 76
3.7 Tandem swing bridges 79
References 83
4 Other movable bridge forms 87
Charles Birnstiel
4.0 Introduction 87
4.1 Market Street Bridge, Chattanooga, TN 87
4.2 Armstrong swing bridges 88
4.3 Movable bridges supported by pontoons 95
4.4 Transporter bridges 99
4.5 The Bellmouth passage bridges 102
4.6 Gateshead Millennium Bridge 106
4.7 Belidor bascules 107
4.8 Folding bascules 109
4.9 Other movable bridge forms 112
References 112
5 Movable bridge design standards 115
Charles Birnstiel
5.0 Introduction 115
5.1 Units 115
5.2 Development of movable bridge design practice 115
5.3 European movable bridge specifications 119
5.4 USA Railroad Bridge Safety Standard 120
References 121
6 Materials of construction 123
Charles Birnstiel
6.0 Introduction 123
6.1 Ferrous materials 123
6.2 Wrought iron 123
6.3 Steels 124
6.4 Heat treatment of steel – general 133
6.5 Heat treatment of steel gears 137
6.6 Cast steel 139
6.7 Hot-rolled steel and hot forging 139
6.8 Cold-finished steel 139
6.9 Cast iron 140
6.10 Non-ferrous metals 140
6.11 Non-metallic materials 142
6.12 Wire rope 143
References 153
7 Material properties and failure 157
Charles Birnstiel
7.0 Introduction 157
7.1 Material specifications 157
7.2 Tensile properties 157
7.3 Material hardness 163
7.4 Fracture of metals 168
7.5 Residual stresses 169
7.6 Corrosion 170
7.7 Stress corrosion cracking 174
7.8 Hydrogen embrittlement 175
7.9 Tribology 177
References 177
8 Span drive arrangements 181
Robert J Tosolt
8.0 Introduction 181
8.1 The simple trunnion bascule 181
8.2 The rolling bascule 184
8.3 The heel trunnion bascule 186
8.4 The Hopkins trunnion bascule 186
8.5 The swing span 190
8.6 The span drive vertical lift bridge 191
8.7 The tower drive vertical lift bridge 194
References 197
9 Machinery components 199
George A Foerster
9.0 Introduction 199
9.1 Shafts, couplings and universal joints 199
9.2 Bearings and bushings 203
9.3 Drums and sheaves 206
9.4 Linkages 207
9.5 Power screws, mechanical jacks and pulling devices 207
9.6 Clutches and torque limiters 208
9.7 Gears, racks and differentials 208
9.8 Parallel shaft, right angle and planetary speed enclosed gear
box reducers 209
9.9 Roller chains and sprockets 211
9.10 Keys, pins, retainer rings, shrink fit devices, collars and
threaded fasteners 211
9.11 O-rings, lip seals and packing materials 215
9.12 Springs 216
9.13 Closing summary 217
References 217
10 Stabilisation machinery 219
George A Foerster
10.0 Introduction 219
10.1 Bascule bridges 219
10.2 Swing bridges 222
10.3 Vertical lift bridges 225
References 229
11 Superstructure structural design 231
Charles Birnstiel
11.0 Introduction 231
11.1 Common movable bridge superstructure forms 232
11.2 Bridge decks 233
11.3 Bascule bridges 238
11.4 Swing bridges 242
11.5 Vertical lift bridges 246
11.6 Movable bridge balancing 248
References 251
12 Mechanical design 255
George A Foerster
12.0 Introduction 255
12.1 Design methods, loadings and load factors 257
12.2 Machinery component design 260
12.3 Main machinery support components for movable bridges 261
12.4 Design of shafts – general 264
12.5 Design of plain and anti-friction bearings 271
12.6 Contact stresses and design of rollers 276
12.7 Selection of wire rope, drums and sheaves 278
12.8 Linkage design 280
12.9 Lock bar design 283
12.10 Wedge design 284
12.11 Selection and design of drive machinery for lock bars and wedges 285
12.12 Selection of shaft couplings 286
12.13 Interference fits, key and mechanical friction locking devices 288
12.14 Brake selection 290
12.15 Bolts 290
12.16 Welding 291
12.17 General gearing 292
12.18 Machinery inspection and maintenance 292
12.19 Other machinery design considerations 293
12.20 Summary 294
References 294
13 Gearing and speed reducer design 297
Robert L Cragg and Robert J Tosolt
13.0 Introduction 297
13.1 Symbols and abbreviations 299
13.2 Gear design 300
13.3 Inspection fundamentals 313
13.4 Gear design considerations 320
13.5 Future considerations 323
References 323
14 Hydraulic span drive systems 325
James M Phillips III
14.0 Introduction 325
14.1 Hydraulic system fundamentals 327
14.2 Hydraulic system components 332
14.3 Heating and cooling of hydraulic systems 340
14.4 Reserve power factor 341
14.5 Hydraulic movable bridge drive types 341
14.6 Open-loop hydraulic cylinder bridge drives with proportional
directional control 350
14.7 Open-loop hydraulic cylinder drives with pump control 353
14.8 Hydraulic motor drives 355
14.9 Design loads for machinery 359
14.10 Design loads for structure 360
14.11 Synchronising or load sharing in hydraulic systems 361
14.12 Design example 362
References 369
15 Electrical system design 371
William Bowden
15.0 Introduction 371
15.1 Prime mover 372
15.2 AC thyristor drives 375
15.3 Flux vector drives and motors 376
15.4 Power synchro unit (synchro-tie) 377
15.5 Auxiliary motors 378
15.6 Brakes 379
15.7 Limit switches and resolvers 381
15.8 Traffic control devices 384
15.9 Electrical power distribution 385
15.10 Control system hardware 386
15.11 Remote controls 390
15.12 Interlocking 390
15.13 Bypass switches 391
15.14 Documentation 392
15.15 Spare parts 393
15.16 Testing 393
References 393
Index 395