Railway Control Systems

324 Pages·1980·74.033 MB·English

by  Nock, Institution of Railway Signal Engineers

Railway Signalling
Editorial Committee First published 1980
Paperback edition 1985
*0. S. NOCK, A.C.G.l., B.Sc., D.l.C., C.Eng., F.l.C.E., F.I.Mech.E., Reprinted 1988, 1989
F.I.R.S.E. Chairman A & C Black (Publishers) Limited
J. H. FEws, C.Eng., F.I.R.S.E., F.I.E.E. 35 Bedford Row, London WCI R 4JH
R. A. POPE, M.A., C.Eng., F.l.R.S.E., M.l.E.E.
© 1980 Institution of Railway Signal Engineers
*L. H. F. TUFF, C.Eng., F.I.R.S.E., F.I.E.E.
• J. F. H. TYLER, B.Sc., C.Eng., F.I.R.S.E., F.l.E.E., F.C.I.T.
All rights reserved. No part of this puhlication may be
*D. C. WEBB, C.Eng., F.I.R.S.E., F.I.E.E. reproduced, stored in a retrieval system, or transmitted,
in any form or by any means, electronic, photocopying,
•Past-Presidents of the I.R.S.E.
recording or otherwise, without the prior permission
in writing of A & C Black (Publishers) Limited
The Committee must express their appreciation of the contributions
made by the following: Messrs B. G. Buckler, A. D. Fleet,
D. J. Glyde, J. V. Goldsbrough, B. H. Grose, D. A. Hotchkiss, British Library Catllloguing in Publication Data
R. T. Hutt, P. C. James, C. Law, C. A. Porter, A. J. R. Rowbotham,
Railway signaUiug: a treatise on the recent
G. C. Smith, D. H. Stratton and R. B. Woodhead.
practice of British Railways.
The circuit diagrams and signalling plans were prepared by I. Railroads-Great Britain-Signal
D. A. Wood. I. Institution of Railway Signal Engineers
II. Nock, Oswald Stevens
625.1'65'0941 TF615
ISBN 0-7136-2724- 7
Typeset by Santype International Limited, Salisbury, Wilts.
Printed in Great Britain by Antony Rowe Limited, Chippenham
Railway Signalling
A treatise on the recent practice of
British Railways
Prepared under the direction of a
Committee of the Institution of
Railway Signal Engineers under the
general editorship
of
0. S. NOCK
Honorary Fellow and Past President
of the Institution
A & C Black · London
Contents and Illustrations
3 The Principles of Interlocking and Control<J 50
3:1 Main features of signalling control panel 51
Foreword vii 3:2 Main signal controls 54
Preface viii 3:3 Main signal and point controls at a right-hand running
junction 57
The Philosophy of RaiJway Signalling I 3:4 Main signal and point controls at a left-hand running
1:1 British Railways' multiple-aspect signalling system 2 junction 58
3:5 Facing points in overlap 61
2 Layout of Signals and Track Circuits 4 3:6 Route locking between signals and points 63
2:1 2-aspect signalling: (A) Rapid Transit (B) British Railways 7 3:7 Opposing signal route locking 64
2:2 3-and 4-aspect signalling 9 3:8 Point to point interlocking 65
2:3 2-Yellow headway in 4-aspect area II 3:9 Double junction on high speed line 66
·w·
2:4 British Railways' standard braking curve 12 3:10 Reciprocal and non-reciprocal locking 67
2:5 British Railways' standard composite braking curve 13 3:11 Conditional and counter-conditional locking 69
2:6 Optimum headway and line capacity and effect of running 3:12 Head and tail movements at a station 71
at a speed less than that for which the line is signalled 19 3:13 Layout relating to examples of control tables 73
2:7 Theoretical and practical oraking technique 21 3:14 Example of signal and route control table 75
2:8 Stopping headway at an intermediate station 22 3:15 Example of point control table 76
2:9 3-aspect stopping headway calculations for an intermediate 3:16 Example of route and approach locking table 77
station 23
2:10 4-aspect stopping headway calculations for an intermediate
station 25
2:11 Effect of train speed on headway 27 4 Equipment: Relays, Signals and Point Machines 78
2:12 Signalling at an intermediate station with loop platform 29 4:1 BR 930 series relay 79
2:13 Layout of signals at a converging junction 30 4:2 Multi-unit colour light signal: optical system 81
2:14 Layout of signals at a double junction 31 4:3 Multi-unit colour light signal: typical beam intensity and
2:15 Layout of signals at a left-hand double running junction 33. range 83
2:16 Double running junctions on high speed lines 34 4:4 4-aspect multi-unit signal: lighting and main filament lamp
2:17 Track circuiting at a divergence of two tracks 35 indication circuit 84
2:18 Track circuiting at a crossover between parallel running 4:5 Main signal on/off indication circuit 85
lines 35 4:6 Searchlight signal: optical system 87
2: 19· Track circuiting at a left-hand double junction 36 4:7 4-aspect searchlight signal: lighting and main filament lamp
2:20 Track circuiting at a left-hand double running junction 37 indication circuit 88
2:21 Subsidiary signal at entrance to siding or yard 38 4:8 Position light junction indicator and optical system 89
2:22 Subsidiary signal at entrance to occupied platform (simple 4:9 Junction indicator: lighting circuit 91
case) 39 4:10 Multi-lamp route indicator 93
2:23 Subsidiary signal as draw-ahead for setting back into siding 39 4:11 Position light shunting signal and optical system 94
2:24 Shunting signals and associated track circuiting 41 4:12 Shunting signal: control, lighting and indication circuit 95
2:25 Signalling and track circuiting at a terminal station 43 4:13 Position light subsidiary signal: control. lighting and
2:26 3-aspect junction signalling 46 indication circuit 97
2:27 4-aspect junction signalling 47 4:14 Point machine drive and lock movement: 'straight through' 99
4:15 Point machine drive 'lnd lock movement: 'in and out' 101
4:16 Split field point machine: 4-wire operating circuit 102
CONTENTS
4:17 Split field point machine: operating circuit sequence 103 6:3 Multiple system of route identification 155
4:18 Penna nent magnet point machine: operating circuit 104 6:4 Typical layout of relay sets: System A 157
4:19 Electric point machine: detection circuit 105 6:5 System A: push button circuits: entrance registration 161
4:20 Point machine control circuit 107 6:6 System A: exit registration 162
4:21 Rail clamp lock: principle of operation and detection 109 6:7 System A: selection and locking levels 164
4:22 Electro-hydraulic point machine (clamp lock type): 6:8 System A: selection and locking levels: relay operating
control and drive circuit I 10 sequence 165
4:23 Electro-hydraulic point machine (clamp lo!=k type): 6:9 System A: point setting circuit 167
detection circuit Ill 6:10 System A: aspect level 169
4:24 Electro-hydraulic point machine (damp Jock type): 6:11 System B: typical layout of relay sets 171
hydraulic operation 112 6:12 System B: push button circuits 173
4:25 Layout for typical 'free-wired' circuit example 113 6:13 System B: route priming calling and locking circuits 175
4:26 Push button circuitry 115 6:14 System B: signal control and route releasing 177
4:27 Control panel indication circuits 116 6:15 System B: point setting circuit 179
4:28 Route LR circuits 117 6:16 System B: route priming calling and locking: relay
4:29 Point setting circuits 118 operating sequence 180
4:30 Sectional release route locking circuits 119 6:17 System B: route priming: circuit operation 181
4:31 Point proving circuits 120
4:32 Aspect control and swinging overlap circuits 121
4:33 Approach locking and auto working circuits 123 7 Track Circuit Principles and Equipment 182
Tables: B 930 series Relays 125-7 7:1 Bask track circuit. occupied 183
7:2 Basic track circuit: dear 183
S SignaDing Control Panel 128 7:3 Example of track circuit calculation 186
5: I Mosaic diagram: part of a control panel and including an 7:4 Insulated rail joint failure: equivalent circuits 187
interlocking that is remotely controlled 129 7:5 Typical bonding of track circuits 188
5:2 Signalling control panel: combined type 130 7:6 Typical series bonding of track circuits 189
5:3 Signalling control panel with separate operating console 131 7:7 Track circuit interrupter assembly 190
5:4 Cross-section of combined type control panel 132 7:8 Typical examples of track circuit interrupters at trap points 191
5:5 Combined type of control panel: diagram showing 7:9 Typical circuits for track circuit interrupters 191
constructional features 133 7:10 Magnetic circuits: DC ordinary and AC-immune relays 194
5:6 Portion of a mosaic diagram inc.luding CCTV monitor 7:11 Cross bonding and loss of broken rail protection 195
screen and controls for level crossing 138 7:12 AC-immune DC track circuit 196
5:7 Signalman's telephone concentrator 141 7:13 Double-element vane relay: details 199
5:8 Part of a desk shelf with train description interpose and 7:14 Double-element vane relay: resonated control winding 201
interrogate facilities 142 7:15 Single rail AC track circuit in DC traction area 202
5:9 Detail of mosaic panel, top unit, spring base and plug 7:16 Double rail AC track circuit in DC traction area 203
coupler assembly 145 7:17 Double rail AC track circuit with resonated impedance
bonds 205
7:18 Double rail AC track circuit with auto-coupled impedance
6 Geographical Circuitry 147 bonds 207
6:1 Track layout and geographical unit representation 150 7:19 Double rail AC track circuit with inductance feed 209
6:2 Track layout and geographical equivalents 151 7:20 Impedance bond: typical saturation curve 211
v
CONTENTS
7:21 Double rail to double rail: impedance bond layout 212 9:9 Stepping table: example 3 268
7:22 Reed filter 213 9:10 Stepping table: example 4 269
7:23 Reed track circuit 214 9:11 Stepping table: example 5 270
7:24 Principles of jointless track circuits 217 9:12 Control Centre panel operator's train description panel
7:25 Jointless track circuit: voltage-operated type 219 layout 272
7:26 Alsthom current-operated joint less track circuit 220 9:13 Fringe box signalman's train description panel layout 273
7:27 Reed jointless track circuit: typical applications 221 9:14 Train berth describer: sequence of panel operator's actions 275
7:28 Reed jointless track circuit: details 222 9:15 Cathode-ray tube as used for train description display 277
7:29 Jeumont impulse track circuit 224 9:16 Cathode-ray tube: formation of characters 277
7:30 Jeumont impulse track circuit: impulse waveform 225 9:17 Cathode-ray tube: display store 279
7:31 Lucas impulse track circuit: impulse waveform 225 9:18 Basic train describer functions 281
9:19 Main components of the computer 281
8 Remote Control Systems 226 9:20 Main components of the computer-based train describer 285
8:1 Comprehensive remote control scheme 229 9:21 Dual computer train describer 287
8:2 Remote control system with individual returns 230 9:22 Computer-based train describer: input multiplexer 289
8:3 Remote control system with common return 231 9:23 Anti-noise precautions 290
8:4 Typical micro-core cable section 232 9:24 Display system module 291
8:5 Basic FDM system 234 9:25 Train reporting system as installed on British Railways
8:6 FDM remote control system: twin reed filter 236 (L.M. Region) 295
8:7 FDM remote control system: part of a fail-safe system 239 9:26 Comprehensive scheme for the automatic compilation of
8:8 Fail-safe reed transmitter: circuit diagram 240 timetables and the provision of other ancillary services
8:9 Fail-safe reed receiver: circuit diagram 241 using train describers currently being installed by British
8:10 FDM remote control: part of a non-vital system 243 Railways (Southern Region) 297
8:11 FDM fail-safe system: token less block 244
8:12 TDM system: input multiplexing 247 10 The British Railways' Automatic Warning System 299
8:13 TDM system: make-up of transmitted messages 249 I 0: I A WS: principle of operation 300
8:14 TDM system: binary methods of carrier modulation 250 10:2 AWS: magnets in track 301
8:15 TOM system: output multiplexing 251 I 0:3 A WS: cab indicator face plate 302
8:16 TDM system: high density traffic scheme (uni-directional) 252 I 0:4 A WS: cab circuits-normal conditions 303
8:17 TDM system: high density single station traffic scheme I 0:5 A WS: cab circuit.s-<ondition immediately after receiver
(bi-directional) 253 has passed over permanent magnet 304
8:18 TOM system: low density multi-station traffic scheme I 0:~ A WS: cab circuits-<:ondition after receiver has passed over
(bi-directional) 255 energised electro-magnet 305
10:7 A WS: cab circuits-<ondition after receiver has passed over
9 Train Description 258 de-energised electro-magnet 306
9:1 Train description by block bell 259 10:8 A WS: cab circuits-condition after driver has
9:2 Magazine train describer 259 acknowledged a caution signal 307
9:3 Magazine train describer: displayed and 'blind' storage 260 I 0:9 Location of A WS magnets 308
9:4 Train berth describer: train description display 261
9:5 Symbols and abbreviations used in train describer systems 264 II The Future 309
9:6 Typical block schematic 265
9:7 Stepping table: example I 266
Index 3ll
9:8 Stepping table: example 2 267
VI
Foreword
The railways throughout the world have changed considerably since
the last comprehensive book on signal engineering was published
in Britain forty years ago. From being a relatively small branch
of railway engineering, it has become a senior profession employing
the most modern technology in the fields of engineering control
and communications.
Signalling and communication systems and techniques are now
an essential ingredient of every activity of railway business and
operations. This book, with all the authority of the Institution,
deals in depth with the modern signalling technology of British
Railways, which is unquestionably one of the busiest and most varied
in the world. The varied traffic requirements of British Railways
and hence the associated signalling practices described in the book
make it eminently suitable as an international treatise for general
reference and advanced studies. I am sure that members of the
profession and students of the rather special art of railway signal
engineering will find it invaluable.
K. E. HODGSON, C.Eng., F.I.R.S.E., F.I.E.E., M.C.I.T.
President, Institution of Railway Signal Engineers
March 1980
vii
Preface
be of interest and value to engineers and operating men on railways
in many parts of the world on which developing traffics require
This book is the result of several years' work by senior members the introduction of improved signalling, to increase line capacity
of the Institution of Railway Signal Engineers. ll describes the more and accelerate service. Equally, it is hoped that the book will be
recent practices of British Railways, historically the first railway of interest to railwaymen in the 'advanced countries', in which
network in the world, and today one of the most modern, fastest, the philosophies of operation and signalling may not necessarily
busiest, and most finely equipped. The book has been prepared be the same as on British Railways, but who may like to make
to be of interest to a wide variety of readers in many parts of comparisons of ideas, just as BFitish based members of the Institution
the world, but primarily for professional signal engineers. of Railway Signal Engineers are so happy to do with their fellow
It is particularly directed towards younger men studying to obtain members overseas on various technical and social occasions.
a wider and more complete knowledge of the subject. The total In presenting this work, however, it is important to emphasise
number of men employed in the signalling industry is small, but that as always, throughout the hundred years and more of its history,
while the most advanced electronic, electrical and mechanical the technology and practice of railway signalling is in a constant
engineering systems are employed, and require a high proportion state of evolution, and the book can be said to be up to date
of men having Chartered Engineer status, the numbers represent only up to the time of final editing, before going to press.
a very small percentage of the railway engineering profession as The Committee wishes to thank the Chief Signal and Telecommuni
a whole and it is impracticable to provide training in the expertise cations Engineer of the British Railways Board, and Messrs GEe
of signalling in Universities and Colleges of Further Education. Ex General Signal and the Westinghouse Brake and Signal Company
perience must be obtained within the industry, and the Institution for their assistance in producing the book and for the valuable
sets and maintains the qualifying standards by the examination needeq suggestions they have made.
to be passed to obtain corporate membership. It is hoped that this Finally, a word of special thanks is due to Mr. P. C. Harris
book will help those making the necessary studies. who, on behalf of Messrs. A. & C. Black, has done a mammoth
Additionally, the members of the committee charged by the Council job in preparing the layout of the book and in getting all the illus
of the Institution with the preparation of this book hope it will trations into the right places!
0. S. NocK
Chairman,
(Past-President)
viii
THE PHILOSOPHY OF RAILWAY SIGN ALLING
CHAPTER ONE
the lineside signals, but to protect him against error on his part
The Philosophy of is more difficult.
In practice a compromise is accepted by British Railways by use
Railway Signalling
of an automatic warning system (A WS.). This warns the driver
of the need to make a brake application such that the train may
be brought to a stand at a signal displaying a Red aspect. Should
this warning be ignored the brakes are applied automatically, and
The essential purposes of a railway signalling system are:
will bring the train to rest before the signal is reached. For practical
(a) to maintain a safe distance between following trains on the reasons, it is necessary that the driver should have the ability to
same track; release and to re-apply the brakes after an automatic application.
Because of this the protection offered to the driver cannot be con
(b) to safeguard the movement of trains at junctions, and when
sidered as complete and, on British Railways, be still therefore carries
crossing a path which could be taken by another;
responsibility for controlling his train .safely, although much has
(c) to regulate the passage of trains according to the service density
been done to make his tasks easier. Full automation on British
and speed required.
Railways is quite feasible, but having regard to the mixed nature
It is also a fundamental requirement that in the event of equipment of the traffic, its density, and the size of the system, it is currently
failure the safety of trains must be ensured. uneconomic. It should, however, be noted that British signal engineers
There are many systems of signalling in use in various parts of have led in the development of fully automated systems of train
the world which satisfy ttiese criteria, but the system used in Great control coupled with advanced techniques in signalling.
Britain is known as multiple aspect colour light signalling (MAS.). While the British Railways signalling system has been developed
It was adopted in 1923, following a report by a committee of the to provide for the safe movement of mixed types of train in conditions
lnstitution of Railway Signal Engineers, and has changed little since. of high traffic density and increasing speed, equipment failure can
It is a very simple system so far as the driver is concerned, and still arise occasionally. On these fortunately rare occasions the signal
has been found capable of coping successfully with the wide range man or the driver may be stripped of the protection provided by
of speeds, varying braking rates, and headway between following the system, and reliance has to be placed on the sense of responsibility
trains on British Railways. Fig. I:) shows the elements of the system, of the men concerned, and upon their knowledge of the British
which may be 2-, 3- or 4-aspect according to traffic needs. Railways Rules and Regulations, and other relevant instructions,
This book describes the current state of signal engineering on which remain as important today as they were in the days of simple
British Railways and shows how it is linked to developing techniques semaphore signalling.
in traction systems, permanent way, and the increasing speed of On British Railways the signalman is provided with all the means
trains. The lineside signals are operated by the signalman, or where necessary to operate the points and signals, generally as a complete
possible automatically, and the signalman is protected from errors route, and he is also provided with continuous indications showing
on his part by the interlocking and controls applied to the signals. the state of the line, the position of all trains in his area of control,
Such protection is complete, barring failure of equipment, as discussed and the position of all points and the state of all signals. Much
later. The driver acts on the authority of the aspects displayed by of the important equipment operates automatically, and further sec-