THE DEVELOPMENT OF RADAR EQUIPMENTS FOR THE , 1935-45 photograph by Seaman Photographers. Sheffield

Cecil Everard Horton, CBE, MA father of British Naval radar

(by kind permission of Desmond Horto n, Esq.) The Development of Radar Equipments for the Royal Navy, 1935-45

Edited by F.A. Kingsley on behalf of the Naval Radar Trust

M © Naval Radar Trust 1995 Softcover reprint of the hardcover 1st edition 1995 978-0-333-61210-1

All rights reserved. No reproduction, copy or transmission of this publication may be made without written permission. No paragraph of this publication may be reproduced, copied or transmitted save with written permission or in accordance with the provisions of the Copyright, Designs and Patents Act 1988, or under the terms of any licence permitting limited copying issued by the Copyright Licensing Agency, 90 Tottenham Court Road, London W1P 9HE. Any person who does any unauthorised act in relation to this publication may be liable to criminal prosecution and civil claims for damages.

First published 1995 by MACMILLAN PRESS LTD Houndmills, Basingstoke, Hampshire RG21 2XS and London Companies and representatives throughout the world

ISBN 978-1-349-13459-5 ISBN 978-1-349-13457-1 (eBook) DOI 10.1007/978-1-349-13457-1

A catalogue record for this book is available from the British Library.

10987654321 04 03 02 01 00 99 98 97 96 95 Contents

~~~~~ ~ List of Tables xvii Preface xix Tribute - Cecil Horton : Father of British Naval Radar xxv Development and Installation of British Naval Radar - Some Significant Milestones xxxiii Notes on the Contributors xxxvii

PART I RADAR EQUIPMENT DEVELOPMENTS, 1935-45 Editorial Note 3

1 The Origins and Development of Radar in the Royal Navy, 1935-1945, with Particular Reference to Decimetric Gunnery Equipments 5 ' .F. Coales %mmary 5 Introduction 6 The research background, 1915-35 6 The formative years, 1935-7 11 The 1937 reorganisation of Naval radar research 16 Preparing for war, 1938-9 21 Early developments in 50-ern radar equipment 23 Wartime developments 29 The need for a surface detection capability 31 The small-ship radar requirement, 1940 33 The requirement for gunnery and fire-control radar (50-ern) 34 Development of Naval gunnery and fire-control radar systems 36 Trials of main armament and high-angle director radars 43 The birth of Naval la-em radar 44 The application of Ifl-cm radar in the Ll-boat war 46 Parallel developments 48 Gunnery radar developments and improvements, 1942 onwards 49

v vi Contents

2 Basic Science and Research for Naval Radar, 1935-1945 67 B. W. Lythall Summary 67 Early history - and two missed opportunities 67 The invention of radar 68 The multiple-cavity anode magnetron 68 The environment for research 69 1938-42 69 1942-5 70 The patterns of research 71 Research themes 71 The need to predict performance 71 Early methods of height estimation 74 Research on the radar environment 75 ~~~~~~ ~ Target reflection characteristics 79 ~~ W Sea clutter 82 Interference with the environment: anti-jamming research 83 Electronic jamming 83 Non-electronic jamming: Window 84 Radar camouflage and echo enhancement 85 Interaction between theory and experiment 86 Antenna developments 87 Transmission lines and waveguides 89

3 Valve Developments for Naval Radar Applications, 1935-45 95 F.M. Foley Summary 95 Introduction 95 Early history of the valve section, HM Signal School 96 Silica as a valve-envelope material 98 Silica-valve technology 98 The electrode system 99 The silica parts 100 The lead-out seals 101 Valve assembly 103 Processing 103 Valve repair 104 Silica valves for radio transmitters 104 Silica valves for radar 106 The start 106 Special developments 107 Contents vii

The end of the era 109 Output power valves 109 Metric-wave valves 109 Decimetre-wave valves 110 Microwave valves 111 Pulse modulators 114 Hard valves 114 Thyratrons 114 Spark gaps 115 Low-power RF valves 116 Duplexer valves 121 Metric valves 121 Microwave valves 121 Mixers 122 General-purpose valves 123 Cathode-ray valves 123 Appendix 1 HM Signal School staff working on valve development up to 1945 128 Appendix 2 Silica valve types 129

4 Royal Navy Metric Warning Radar, 1935-45 133 J. S. Shayler Summary 133 Introduction 134 Types 79X and 79Y (the first successful metric wavelength radar for shipbome installation) 135 Type 792 (the improved equipment) 140 Type 279 (introduction of ranging panel, becoming Type 279) 144 Types 79B/279B (development of common transmit/receive switch, for single antenna operation) 147 Type 281 (development of a 90MHz equipment for increased ranges on aircraft, plus a surface detection capability) 151 Type 281B (development of a T/R switch for Type 281) 161 Type 281BQ (start of experimental work on a continuously rotating antenna system, for use with a PPI display) 162 Dual installations of Types 79B and 281BQ (development of dual installation for gapless cover on aircraft targets) 165 Type 286 (adaption of RAF ASV set as small-ship radar) 169 Type 290 (attempt to develop an improved Type 286) 172 Type 291 (successful development of replacement for Type 286) 173 Type 960 (initiation of development of a replacement for the combined Type 79 and 281 equipments) 175 viii Contents

Postscript 177 Appendix 1 Chronology of development of metric radars 181 Appendix 2 Summary of main characteristics of metric radars 182

5 Development of Naval Warning and Tactical Radar Operating in the 10-em Band, 1940-45 185 C. A. Cochrane Summary 185 Preface 185 Introduction 188 Origins of the first Naval em-radar 189 The first operational centimetric radar 195 Technical constraints and characteristics of Type 271X 197 In the wake of HMS Orchis 203 Coast and harbour defence applications 206 Types 271, 272, 273 in service, 1941-2 208 Anti-submarine range performance of 5 KW centimetric radar 211 The high-power magnetrons 215 The Mark 4 development: Types 271Q and 273Q 217 The Mark 5 development 224 The Mark 5 experimental shore trials - Type 277T 226 The Mark 5 experimental shipborne radar - Type 277X 228 Sea reflection and target indication - Types 276 and 293 231 WS tactical radar - low air warning - heightfinding - Type 277 239 Further development of Type 277 - Types 277P and 277Q 245 Centimetric fighter direction (FD) radar - initial proposals 246 Revised proposals for FD radar - Types 980 and 981 249 The unknown factor in Type 980 (982) performance 255 Conclusions 258 Appendix 1 The complimentary role of X-band for WS radar 259 Appendix 2 Chronology of developments of Naval radar for air and surface warning 267 Appendix 3 Characteristic data for Naval 5-band warning radar 271

6 The Royal Navy and IFF - Identification Friend or Foe, 1935-45 277 J. S. Shayler Summary 277 Introduction 277 The Beginning 278 Contents ix

IFF Mark I 278 IFF Mark II 279 IFF Mark III 281 IFF Mark IV 289 IFF Mark V 289 Postscript 290

PART II RADAR SHIP-FITTING AND MAINTENANCE, 1939-45

Editorial Note 293

7 Radar Ship-Fitting and Maintenance in the Royal Navy, 1939-45: Experiences at Scapa Flow, May 1940 to April 1942 295 B. G.H. Rowley ~~ry m Appointment to HM Signal School 295 Appointment to the staff of Cein-C, Horne Fleet 296 ~~~w m Expanding activities 299 Summer 1940 299 Autumn 1940 302 Early 1941 302 Summer 1941 303 Early 1942 304

8 Radar Maintenance at Sea: A Personal Story, 1940-5 305 R.A. Laws Summary 305 Introduction 305 Author's radar experience 306 Personnel 306 Fitting out and commissioning 307 Acceptance of a new ship 310 At sea 311 Handbooks and test gear 312 Spares 313 Calibration and setting up 314 Metric sets 314 Range scales 315 Index errors 316 Angular alignment 316 Anti-jamming 317 x Contents

Receivers 317 Transponders 317 Preventive maintenance 317 State of readiness 317 Logs 318 Open-wire feeders 318 Tuning the transmitter 318 Common T/R 319 Malfunctions 319 Types 282-5 319 Antenna control 320 Breakdowns 320 Modifications 322 Ancillary services 322 Cooling 322 Power supplies 323 Data transmission 323 Tribute to the Service 323 Appendix 1 Main radar sets encountered by the author 324 Appendix 2 Author's collection of useful texts 324

9 Naval Radar, Fitting Policy, Materiel Procurement, Installation, Sea-Trials and Shore-Based Maintenance 325 A.M. Patrick Summary 325 Introduction 325 Formulation of Admiralty radar-fitting policy and programmes 329 Procurement of radar equipment 330 From Naval Stores to dockyards/shipyards 331 The ship fitting-out task, 1939-45: an overview 334 Pre-fitting work on-board ship 335 Electrical work 337 Radar installation, testing and trials 338 Equipment trials 339 Shore maintenance 340 Replenishment 341 The Port Radar Officer Organisation 342 General 342 Sherbrooke House, Glasgow 343 The radar officer organisation, 1939-45 344 Conclusion 347 Postscript 348 Contents xi

Appendix 1 Type Numbers of Naval Radar Sets, Operational or Designed, 1935-45 353

Appendix 2 Tabulations of Radar System Data, 1935-45 359

Appendix 3 Ship-Fitting Tables, 1938-45, Arranged by Class of Ship 387

Appendix 4 Table of Manufacturers Employed on Naval Radar Developments 401

~~~ ~ Select Bibliography 415 Index 421 List of Illustrations

1.1 Organisation of Experimental Department, HM Signal School, 1919 8 1.2 Organisation of the Experimental Department of Signal School in September 1937 18 1.3 The November 1937 reorganisation of research (R Department) 20 1.4 Close-range director with experimental 600 MHz Yagi antennae at the AA range, Eastney 35 1.5 (a) Horizontal polar diagram of the Yagi antenna installation; (b) vertical polar diagram of the Yagi antenna installation 35 1.6 Experimental 24-dipole tapered array for Type 284 undergoing field trials 39 1.7 (a) Horizontal polar diagram of 24-dipole 'pig-trough' array; (b) vertical polar diagram of 24-dipole 'pig-trough' array 40 1.8 Office equipment of Types 282, 284 and 285 (600 MHz); modulator and receiver on the right, transmitter in resonant cylinder centre, display with rangefinder on the left 40 1.9 Diagram of 24-dipole array, showing how power is partitioned 42 1.10 Type 284 Yagi array on the LA director in Suffolk, with Type 285 Yagi array on the HA director, further aft 42 1.11 Organisation of Radar department under C. E. Horton in October, 1942 50 1.12 Diagram of 6-Yagi antenna array with rotary switch 52 1.13 (a) Horizontal polar diagram of switched 24-dipole array; (b) horizontal polar diagram of switched 6-Yagi array 52 1.14 Vertical polar diagrams of antennae of Type 279 (43 MHz) and Type 281 (90 MHz), with that of Type 273 (3000 MHz) added 55 1.15 Organisation of Radar Department under Dr S. E.A. Landale in October 1943 58 1.16 Organisation of the Communications Department, ASE in October, 1944 63 3.1 Corrugated envelope for NT22B 100 3.2 Typical bulb with end-cap fitted 101 3.3 Lead seal 102 3.4 Graded-glass seal 103 3.5 H. G. Hughes and T. E. Goldup sealing-off a silica valve, 1922 105

xiii xiv List of Illustrations

3.6 The NT57T silica valve 108 3.7 A 'Micropup' triode, NT99 111 3.8 An early magnetron, NT98 112 3.9 Magnetron cavity strapping 113 3.10 High-power thyratron modulator, CV22 115 3.11 Outline of 'acorn' valve 117 3.12 600 MHz amplifier triode, CV53 118 3.13 Local-oscillator klystron, NR89 (CV35) 119 3.14 Cross-section of local-oscillator klystron, CV67 120 3.15 Duplexer arrangement 122 3.16 The microwave crystal mixer, CVI0l 122 3.17 Receiving valve outlines 124 3.18 Electrostatic focus and deflection CRT 125 3.19 12-in electromagnetic focus and deflection CRT 126 3.20 The Skiatron tube for optical projection, NC17 127 4.1 Type 79/279 antenna array, with Type 243 IFF antenna mounted above 137 4.2 Rear of Type 79 equipment in the Transmitter Office 143 4.3 Type 79 equipment in the Receiver Office 144 4.4 Schematic of Type 279B T/R switch 149 4.5 Vertical lobe structure, Type 79/279 and Type 281/281B 150 4.6 Type 281 equipment in the Transmitter Office 155 4.7 Type 281 transmitter array 156 4.8 Type 281 receiver array 157 4.9 Effect of switching on Type 281 receiver array polar diagram 158 4.10 Equipment in a Type 281 Receiver Office 160 4.11 Type 281BQ RF sliprings 164 4.12 Equipment in Type 281BQ Receiver Office 166 4.13 Early Radar Display Room 168 4.14 214 MHz array for later Type 286s and Types 290 and 291 171 5.1 Rear view of the Type 271 antenna 197 5.2 The 'office' /lantern installation on HMS Periwinkle constructed by the Dockyard, shown before the installation of Type 271 198 5.3 Front view of the Type 271 antenna 199 5.4 Diagram of the feed dipole and rod reflector of the Type 271 'cheese' antenna 199 5.5 Schematic diagram of crystal holder and crystal for the mixer unit: (a) original full-wave line form for TRE laboratory crystalr; (b) adaptor to US capsule-type production crystal; (c) quarter-wave inductance line mixe 201 5.6 Type 271X panels in the original vertical format manufactured in the experimental workshops and by Allen West Ltd: (1) high-voltage rectifier; (2) modulator; (3) tetrode List of Illustrations xv

series-modulator valve; (4) power-supply panel; (5) A-scan display; (6) receiver panel 202 5.7 Rear view of Type 273 antenna 205 5.8 Type 271P panels: the early Type 271 panels redesigned for main production. The modulator with power supply is below; the receiver, display, and the associated power supplies are immediately above; the G82 tuning test set is on top 209 5.9 Effect of the lantern on the Type 271 radiation pattern (a) Teak lantern with plane perspex windows; (b) cylindrical perspex lantern 211 5.10 HMS Suffolk with Type 273 raised on stalk for clear view over high-angle director to left and low-angle director to right 212 5.11 Type 271Q panels designed to fit the same space as Type 271P panels, for ease in conversion: (1) discharge-line modulator unit; (2) receiver and display unit 218 5.12 Type 271Q transmitter mounted behind the antenna: (1) magnet; (2) magnetron; (3) flexible bellows coupling of magnetron to output line; (4) Current transformer to monitor magnetron pulse; (5) cooling fan; (6) matching adjustments on output line; (7) voltage step-up transformer for modulator pulse; (8) waveguide to antenna 219 5.13 Type 273Q antenna with waveguide transmitter feed 221 5.14 Type 273Q antenna - rear view showing (1) waveguide feed to horn; (2) transmitter unit; (3) stabiliser to hold beam horizontal; (4) gas switch to protect receiver crystal; (5) crystal mixer and IF head amplifier 221 5.15 Type 277T trailer installation with large 'cheese' antenna in a fixed position on the roof: (1a) horn feed; (1b) 'cheese'-type reflector; (2) interrogater antenna (a) dipole feed, (b) reflector; (3) rotatable cabin having transmitter, receiver and display 227 5.16 The Type 277X antenna - note the sheet-metal paraboloid 229 5.17 HMS Janus with the experimental Outfit AUR antenna of Type 293Xon top of a lattice mast - note the HF DF pole-mast installation behind 233 5.18 Predicted vertical coverage diagram for Type 293X 234 5.19 Bar-chart presentation of PPI 'signal/no signal' versus range for 14 radical flights at constant aircraft height 235 5.20 Vertical coverage of Type 293X as determined by trials against a Boston aircraft target: (a) height versus range - aircraft opening; (b) height versus range - aircraft closing 236 5.21 Type 276 (Outfit AU]) antenna identical to the Type 271Q transmitting antenna with aperture sealed to permit use in exposed sites without the need for a radome 237 xvi List of Illustrations

5.22 Vertical coverage of Type 276 as determined by trials 238 5.23 Type 293M antenna replacing the Outfit AUR used in the Type 293X trials 239 5.24 Type 277 antenna Outfit AUK: (1) wire-mesh parabolodial reflector; (2) waveguide rotating-joint on elevation axis; (3) gyro vertical-stabiliser 240 5.25 Type 277 in HMS Campania: height versus range diagram for a single Fulmar aircraft 241 5.26 HMS Campania: analysis relating probability of 'paint' to target-acquisition probability 243 5.27 Comparison of vertical coverage diagrams of Types 281 and 277 244 5.28 Types 982, 983 and 960 at the Royal Naval Air Station, Kete 250 5.29 Vertical coverage diagrams of the tilted 'cheese' array for different phase conditions of the feed 251 5.30 Type 980: trials against a Meteor aircraft at 20000-ft: analysis of 10 flights, opening and closing range 253 5.31 HMS Eagle, circa 1951 254 5.32 Air-defence picket Llandaff 257 5.33 Type 261 installed in Saltburn for trials 261 5.34 The Type 268 radar antenna 265 5.35 The Solent as seen on the PPI display of a 3-cm radar 266 6.1 Type 243 antenna and feeder system 283 6.2 Type 243 antenna mounted above Type 281 array 284 6.3 Type 941 antenna mounted above Type 281BQ antenna 286 7.1 Scapa flow: the Home Fleet anchorage 297 8.1 The modified mainmast of Anson 309 9.1 Formulation of Admiralty radar fitting-out programme 327 9.2 Implementation of radar ship-fitting programme 328 9.3 Plan-packing scheme for a hypothetical radar 332 9.4 Relevant sections of plan-packing notes covering complete delivery in three consignments 333 9.5 Sherbrooke House, Glasgow 343 List of Tables

1.1 Characteristics of typical Naval gunnery radar sets 61 4.1 Detection ranges on aircraft and ships in the Saltburn trials 175 5.1 Radar detection ranges on Ll-boats, 1942-5 214 5.2 Type 261 trials, November 1942 262

xvii Preface

This book contains a series of technical monographs dealing with various aspects of British Naval radar from its inception in 1935 until the end of World War 2. It stems from several years of collective historical research by a group of scientists, Naval officers and certain representatives of the electronics industry, all personally involved some forty or fifty years before. It is one of two such volumes, both of which are complementary to Derek Howse's book Radar at Sea - the Royal Navy in World War 2, published in 1993, which is addressed more to the general reader. The background research, preparation and publication of both books has been sponsored by the Naval Radar Trust. Whereas Radar at Sea is a carefully researched historical treatise by a single author, this book is a collection of accounts by people who actually worked at HM Signal School (later the Admiralty Signal Establishment) ­ or were associated closely with it - during the period in question. The subjects are treated in considerably more technical detail than was possible in Radar at Sea . With few exceptions they are based on the individual authors' own contemporary experiences, supplemented by extensive archival research and discussions with surviving colleagues in order to safeguard against the fallibility of human memory.

THE NAVAL RADAR TRUST

The idea that sparked off this venture was the brain-child of Professor J.F. Coales, who had been intimately involved with Naval radar both before and throughout World War 2. In June 1985, half a century after the first historic experiments for the Air Ministry, the Institution of Electrical Engineers organised a seminar on 'Fifty Years of Radar', to which Coales, in collaboration with the late J.D. S. Rawlinson, contributed a paper dealing with the early stages of Naval radar in Britain. The realization that so little else had been included about the Navy's contribution, as opposed to the other two Services, led him to put forward the idea of assembling a comprehensive collection of archives on British Naval radar, not only for the historical record, but also in the hope that one day it would lead to a published account. A start was made by contacting those civilian and Naval officers involved whose whereabouts were known, and by gathering archival material - personal notebooks, recollections, photographs and so on. In

xix xx Preface

December 1985 a working reunion of more than 40 wartime colleagues was held at Churchill College, Cambridge, at which it was agreed to proceed with Coales' idea. Since all concerned were at least in their sixties, and many in their seventies and eighties, it seemed important to get on with the collection and digestion of data as soon as practicable. From these beginnings the project steadily gained momentum. An Administrative Committee was elected to manage the enterprise; this was subsequently formed into the Naval Radar Trust, with charitable status and with the following membership: • Sir Hermann Bondi, KCB, FRS, then Master of Churchill College, Cambridge; formerly Chief Scientific Adviser, Ministry of Defence. • Professor J.F. Coales, CBE, ScD, FEng, FRS, Emeritus Professor of Engineering, University of Cambridge. • Basil Lythall, CB, formerly Chief Scientist, Royal Navy, Member of the Admiralty Board, and Deputy Controller of the Navy for Research and Development. • D. Stewart Watson, CB, OBE, formerly Director of the Admiralty Surface Weapons Establishment; Deputy Chief Scientist, Navy; and Director General of Establishments, Ministry of Defence. By December 1986 Coales had contacted some 150 wartime colleagues. At a second reunion it was resolved to continue with archival research and to aim towards the preparation of a book, for the general reader, which would tell the story of the early development of British Naval radar and its operational use at sea. In the hope that adequate financial support would eventually be forthcoming Derek Howse was appointed to be the author designate - a major act of faith which eventually proved justified when Radarat Sea was published at the beginning of 1993. This book could only tell the technical story in very general terms, so it was also decided to prepare a series of more definitive technical papers, both as authoritative technical background for the general book and to supplement the growing archival collection. Working groups were set up, each with a convener who volunteered to start the preparation of a monograph on a selected topic, such as an individual family of radars, a specialised set of techniques, or a particular aspect of the use of radar at sea. The next few years saw several more reunions; the majority of the monographs reached completion, each in its tum being added to the archives, and the original list of topics was extended to make the collection more comprehensive. It has now become possible to publish all these monographs, together with additional reference data. In view of the large amount of material the collection has had to be split into two separate books, each with an integrated bibliography and index. The present volume is concerned with radar development; it gives an overview of work in the Experimental Preface xxi

Department of HM Signal School (later the Admiralty Signal Establish­ ment), and describes each of the main programmes of radar equipment development, the underlying research, and some of the problems of installation, operation and maintenance at sea. A companion volume1 describes the application of radars in systems - for target indication, weapon direction, command-and-control, and fighter direction. It also includes the story of British Naval radar countermeasures, a technical history of HF DF (which, in conjunction with radar, made a most important contribution to the Battle of the Atlantic) and an essay on parallel developments in German naval radar over the same period. Although all the monographs were initiated as part of a common venture, each one was originally prepared as an independent contribu­ tion dealing with one major topic, and not necessarily depending on other monographs to provide background or to set the general scene. Not surprisingly there were considerable areas of overlap. There were also the expected differences of style, balance and depth of technical detail, and a few apparent inconsistencies. It has been possible to address some of these aspects in editing the present volume, but inevitably examples of overlap must remain.

SOURCES

A primary source of information has been the surviving records of the Experimental Department of HM Signal School, and its successor the Admiralty Signal Establishment. Some of these are held at the Public Record Office; others remain in the Defence Research Establishment, Portsdown, now part of the Defence Research Agency, and are not yet available to the general public. Other important sources of information exist at the Defence Research Establishment, Malvern (in the wartime archives of the Telecommunications Research Establishment); at HMS Collingwood; at HMS Dryad; and at the Ministry of Defence's Naval Historical Branch in London. A certain amount of material is also to be found, rather widely scattered, in other files at the Public Record Office. There is one major published source of technical information, concerned with the whole range of Service radar developments during the war. This is the 'Proceedings of the Radiolocation Convention' held by the Institution of Electrical Engineers in London in 1946. A few more papers were subsequently published in the Institution's Journal, and in other scientific and mathematical journals. Supplementing this is a wealth of collateral information received from private individuals. Many scientists and serving officers attending the reunions have written their own recollections, lent or given personal papers, and provided other information. Tape recordings have been xxii Preface made of recollections of the few people now available who worked on radar well before the war. To this has been added the very extensive collection of historical detail and personal reminiscences assembled by Derek Howse during the preparation of Radar at Sea . The whole now forms a most valuable archive, which is to be deposited in the Archive Centre at Churchill College, Cambridge, where it will be cared for professionally, in company with many other Naval papers of World War 2. Sources are provided in more detail in the Bibliography.

ACKNOWLEDGEMENTS

Our first thanks must go to all the authors of individual monographs, particularly to John Coales, without whom the project would never have been started. The source material is now very diffuse, and a great deal of painstaking work has been necessary for each author to piece together the various elements of the story as accurately as possible. For the appendices Alan Laws prepared the collection of technical data sheets, and Derek Howse provided the guide to the complex ramifications of radar type numbers and the tables of ships fitted with radar - most valuable reference material compiled during the preparation of his own book. Alex Rae prepared indexes for both volumes - as well as compiling a series of staff lists to be deposited in the Churchill Archive Centre. Thanks are also due to other members of the original working groups, and to many other colleagues, for helpful contributions and discussion. Some are acknowl­ edged in specific monographs; it is impossible to mention all the many others who have contributed so enthusiastically in one way or another. We are grateful to many Defence authorities for allowing access to their archival collections, particularly Janet Dudley, formerly Senior Librarian at the Defence Research Establishment, Malvern; John Briggs, Librarian at the Defence Research Establisment, Portsdown, Lieutenant­ Commander Bill Legg of HMS Collingwood, and Lieutenant-Commander Peter Lee of HMD Dryad for their willing assistance. John Briggs was exceptionally patient and helpful in responding to numerous requests for access to the many old technical reports, memoranda and miscellaneous uncatalogued papers and photographs that remain at Portsdown, as well as providing copies for use as working material. Here a special word of thanks is due to Sid Wright, who gave up a great deal of his time to make numerous journeys to Portsdown, Collingwood and Dryad on behalf of authors unable to visit there themselves. His diligence in following up many queries, and his own extensive knowledge and experience of wartime radar have been invaluable. Preface xxiii

The majority of the photographs and illustrations in this volume were provided by courtesy of the Defence Research Establishment, Portsdown; the Naval Historical Branch, Ministry of Defence; HMS Collingwood; HMS Dryad and the Defence Research Establishment, Malvern. Other examples were provided by the Imperial War Museum, Herr Fritz Trenkle, London News Agency Photos, Ltd (which company it has not proved possible to trace), E. B. Callick and Peter Peregrinus, Ltd. Permission to use this material, as identified in individual figure captions, is gratefully acknowledged. Fred Kingsley has not only contributed two monographs to the second book but has been an exemplary editor for both volumes. Faced with a diverse collection of papers, some already published elsewhere, some in various stages of preparation, and a few not even started, he set about his thankless task with determination. It is mainly owing to his industry and application that the two volumes emerged in such good time after his appointment, and that its component parts were welded, with tact, persuasion and persistence, into a reasonably consistent whole. John Coales, Derek Howse, Basil Lythall, Harry Pout, Jack Shayler and Stewart Watson (in alphabetical order) acted as an informal advisory group, to which Alec Cochrane has actively contributed from overseas; Jack Shayler has been particularly conscientious in reading every monograph and providing constructive comments. Thanks are also due to Miss Carin Dean for patiently and expertly reproducing many of the original drafts to professional standards, and to Mrs Sheila Barker, who undertook several complex processing tasks with complete success. Finally, the Naval Radar Trust is most grateful to the Ministry of Defence, Mr David Packard, and the Medlock Charitable Trust for major financial help, without which all the research and collection of archival material could not possibly have been carried out, nor the books published. Other valuable contributions were received from BICC plc, GEC-Marconi Ltd, the Royal Society and the Fellowship of Engineering, as well as many generous contributions from individuals, both Naval and civilian, who were involved in the developments during World War 2. Without their financial help and without the support and industry of so many wartime colleagues, who gave freely of their time and energy without reimbursement, this book could never have been completed.

Esher, Surrey BASIL LYTHALL 1994 On behalf of the Naval Radar Trust

Reference

1. F.A. Kingsley (ed.), The Applications ofRadar andOther Electronic Systems in the Royal Navy in World War 2 (Macmillan, 1994). Tribute Cecil Horton: Father of British Naval Radar Basil Lythall

The collections of articles in the present volume, and its companion/Ion the early technical history of British Naval radar would not be complete without some recognition of the key part played by Cecil Horton. Almost every British seagoing radar that saw service in World War 2 - and several land-based offshoots - first came into being under his leadership; indeed, apart from a short gap, he was in charge of Naval radar developments from late 1937 until well after the war. It was very much owing to his drive and insistence that the Navy entered the war with some ships actually fitted with radar, and with many more sets on order. And throughout most of the great wartime expansion it was his hand at the helm that enabled such a catholic variety of talents to work so effectively together. In retrospect, his contributions to wartime radar, recognised with the award of CBE in the 1946 Birthday Honours, can be seen as a pinnacle in his long record of distinguished achievement. Horton joined Signal School in 1921/ and for many years led a small section working on radio direction-finding. Ouring the 19205 the increasing use of short radio waves for communication with ships pointed to the need for high-frequency direction-finding (HF OF) at long range. Horton realised that this would only be possible in ships if the existing antennae could be replaced by rotating framecoils fitted high above the superstructure and rigging. By 1930 plans had been laid for developing equipment using remotely controlled coils at the top of the mast, and it is a great tribute to Horton and his tiny team that the Royal Navy led the world in ship direction-finding throughout the 1930s. No foreign ship at the Naval Review at Spithead in 1937 had a OF antenna sited where it could possibly have been used at frequencies above about 1.5 MHz, whereas HMS Newcastle could operate up to at least 22 MHz. And throughout the war that followed at least some German scientists still believed that HF OF on-board ship was not possible? Horton's programme included research on radio propagation, collaborating with and advising the Radio Division of NPL. It was largely because of this Admiralty interest that Watson-Watt and his colleagues were encouraged to work on radio propagation and

xxv xxvi Cecil Horton: Father of British Naval Radar ionospheric reflection phenomena in the early 1930s. This led to the birth of British radar when, following Watson-Watt's pioneering work in 1935, it was decided that the vital importance of radar to the RAF justified the setting up of an experimental establishment at Bawdsey dedicated solely to this field.

THE EARLY YEARS OF NAVAL RADAR

In contrast, the Navy decided that work should be pursued in an existing establishment already familiar with the seagoing environment, with its particular requirements and restrictions - entrusting it to HM Signal School, under the control of the Director of the Signal Department of the Admiralty. In August 1935 - almost exactly four years before the war - a small scientific effort was authorised for work on shipborne radar, but the Admiralty did not at first attach anything like the same importance to the new invention as did the Air Ministry. Radar became just another item, without any special priority, in a signals-oriented establishment. The scientific effort was much too small, spread over too many lines, and above all lacked the priority to obtain adequate supporting services. After two years a metric radar had reached only an early experimental stage, as yet with no indication that even the minimum operational requirements were likely to be met in a reasonable time scale. This, it should be recalled, was at about the same time that operational radars were actually being installed in German warships.3 Such was the sorry situation when, late in 1937,Horton was brought in to take charge, assisted by a handful of scientists also transferred from other work in Signal School. Perhaps more than anyone else at that time he appreciated the importance and potential of radar in the Navy, and how unfavourably the attitude towards it had compared with that of the RAP. To quote his own words ten years later, in an address to the Senior Officers' War Course: 'This establishment failed to see the significance of radar, and as late as 1937 it was a matter of great difficulty to get workshop and drawing office effort put on to it. The reason was always the same - other and more obvious demands took priority'. Horton's immediate concern was how to concentrate his meagre resources towards getting practical systems to sea. This depended on the relative priorities of aircraft and ship detection, since there were grounds for believing that the former could be achieved sooner at a metric wavelength, whereas shorter wavelengths offered longer-term potential for detecting ships and low-flying aircraft. Agreement was reached to give first priority to an aircraft-detection radar, with any ship-detection capability it gave as a bonus. Horton was then able to devote a major part of his resources to the rapid improvement of the experimental metric Cecil Horton: Father of British Naval Radar xxvii radar (Type 79X) in which antenna, transmitter and receiver all underwent major changes. The effort remaining was concentrated upon experimental work for decimetric radars, and all other current lines of work were abandoned. This concentration of technical effort was not in itself enough. Horton also needed the conviction and courage to fight an organisational battle to achieve a more equitable division of supporting services between communications and radar. To win required great determination, but win he did, and the outcome was a separate radar division under his leadership, able in its own right to demand more effort in design, production and ship-fitting. The results were dramatic. Within months not only had most of the significant shortcomings of the metric radar been removed, but two ships of the fleet had already been fitted with development models, and were reporting results of detection ranges against aircraft. Although there was no margin for any degradation from peak performance the results were enough to justify early ordering of production models. In parallel with all this the decimetric work had been put on a realistic basis to develop a series of gunnery radars, which entered the fleet from 1940 onwards. During these pioneering years Horton's policy was to shield his staff as far as possible from organisational pressures and to allow them to concentrate on their work. He was constantly in touch with his section leaders, but never needed to call them formally together. Requests for equipment or resources would quietly be fulfilled, with no indication of the battles that had been fought to obtain them. Externally his dry, almost diffident manner belied a firmness of purpose and an ability for staunch resistance and pungent criticism when the occasion demanded. A typical example was his forthright rejection of Watson-Watt's advice at the Tizard Committee, despite the apprehensions of Admiral Somerville, that the Navy should limit itself to fixed antennae for shipborne radar.

THE WARTIME YEARS

The new radar organisation soon had to accommodate the large wartime build-up of staff, slow at first but then rapid. Its success may be judged by the fact that the next three years saw the development of the majority of the Naval radars that were to become operational in World War 2, including a second metric set (Type 281), the family of decimetric gunnery radars, the small-ship radars (Types 286/291) and the first centimetric sets. By mid-1942 most of the radar work had been concentrated into a department at Witley. The programme had continued to expand, so that many more new families of radar systems and variants were being xxviii Cecil Horton : Father of British Naval Radar worked on at the same time. Horton appreciated the need for explicit planning and coordination; this had hardly needed formal definition in his tiny prewar group but had become progressively more important as the scale of activities increased. He introduced a novel organisation (see Monograph 1) in which the conventional 'component' divisions, each responsible for a specific technical area, were supplemented by three small but powerful 'equipment' divisions, each headed by a senior man and concerned respectively with Tactical Radars, Fire-Control Radars, and other systems, including IFF. Their responsibilities included overall planning of each individual system, defining the elements to be provided by each component division, ensuring technical compatibility between all components of the system, and monitoring progress. They were also the main points of contact with Naval application officers in the Establish­ ment, and staff at similar level in Admiralty. Horton's new organisation also had to be flexible enough to make good use of the catholic variety of scientific staff that continued to arrive in increasing numbers. Of course there were many young graduates, not only in physics and engineering, but in a number of other disciplines whose relevance to radar was less immediately obvious; there were also some more senior people with practical experience in industry, or with distinguished academic records in universities, and in addition there were contingents, temporarily in uniform, from allied nations whose countries had been overrun. The mainstream of development still lay in the four 'component' divisions concerned with the essential elements of a radar - antennas, transmitters, receivers and displays - but in the new organisation these were supplemented by a variety of other divisions concerned with particular techniques, measurements, or aspects of research. While the great majority of recruits were assigned to the mainstream divisions, others could be more profitably employed elsewhere. Some of the more senior men worked in small specialist groups to develop techniques for use in future systems. Others were able to take a broader look; for example a division consisting of a small group of mathematicians and theoretical physicists (several of whom subse­ quently became FRS) was effectively given a free hand to look at fundamental issues affecting radar performance, including features of the physical environment in which it had to work. These arrangements defied orthodox precepts; for example the division of responsibility between equipment and component divisions was not sufficiently well-defined, and so tended to be influenced more than it should have been by personalities in one or other camp. Again Horton had up to 15 people reporting directly to him, which could have made it difficult to maintain adequate coordination and control. Nevertheless the arrangement worked remarkably well. It may well not have made the best use of every individual, but to attempt this would Cecil Horton: Father of British Naval Radar xxix probably have been self-defeating because of problems of rank and personality. It certainly made the fullest combined use of the available talent, as indeed it was designed to do, and it continued essentially unchanged throughout the War . The scale of activities now demanded regular and somewhat large meetings of all the senior staff, at which Horton acted very much as 'first among equals'. There was much vigorous discussion and airing of views, but Naval and civilian colleagues all played as a enthusiastic and happy team, and this informal but workmanlike attitude permeated the whole department. Effectiveness and output were remarkable, and for many of us the high morale and intimate, happy-family atmosphere of those days have never really been equalled. Of course we were all stimulated by the fight for national survival, but the spirit also owed much to Horton's ability to bring out the best from this great variety of human talents. The raw university recruit, the distinguished academic, the seasoned engineer from industry, though some of them might see him only rarely, all warmed to his friendly and unassuming manner, as indeed the pre-war scientific stalwarts had done before.

THE POST-WAR RESTRUCTURING

After a period in Admiralty headquarters Horton returned to ASE to become Chief Scientist of the whole Establishment, responsible for communications and allied subjects, as well as radar. After the end of the war the numbers diminished as many wartime recruits returned to their chosen careers in universities or industry, but ASE was still very much larger than its prewar counterpart, with many by now experienced people opting to remain with the scientific civil service. A new era was beginning. It was time to adapt to a more measured progress, but capable of easy expansion should emergency arise in the next five years - as indeed it did in the shape of the Korean War. Within the Admiralty the vision was still that of a 'blue-water' navy, and project demands were becoming more elaborate and complex, particularly as the guided weapon began to overtake the gun as the Navy's future main armament. At the same time, financial and other administrative controls were returning to their former stringency after the relative flexibility of wartime. Horton recognised that demands on the Establishment would undoubtedly greatly exceed the supply, and stressed the need to focus on a limited number of important projects whilst preserving a degree of high-quality scientific work towards the future. Early in 1947 he introduced a fundamental change from previous practice by introducing an organisation based on project groups. Within each group individual projects would be executed by largely self- xxx Cecil Horton: Father of British Naval Radar contained teams, able to conduct their own applied research to establish the necessary techniques, and then to produce their own engineered experimental models for sea trials. From the start each team was to include design/development engineers - seconded from the develop­ ment department, but reporting to the project leader - including the man who would subsequently be responsible for taking the project through its development stages. A project coordination party was charged with system coordination, forward planning and assessment studies. Project leaders now had not only the authority but most of the resources necessary for their task, rather than having to be customers of the various techniques groups, each committed to supporting several projects. There was also a more effective combined use of experimental and design staff. Horton had to live for the time being with the traditional division between the development department and the experimental organisation, both of which now reported to him, but this was the first move towards their eventual integration. Another novel feature was a centralised Post-Design Services Division, which served to free the project groups from continuous repercussions from the past. It was able to take an independent look at complaints against existing designs and was empowered to approve and implement essential changes; more ambitious modifications advocated by enthusias­ tic customers (and sometimes by the original designers') had to fight for priority with the ongoing programme. Resources for basic research, design and development, inspection and test, ship-fitting and so on were also under separate centralised control, each reporting directly to the top. It cannot be said, however, that this visionary new structure was permeated by the same vital spirit that existed at Witley in the early days of the war. Of course there was no longer a threat to national survival, and the Establishment was still inconveniently dispersed over a number of sites, but there were other difficulties. For example the project groups did not report to Horton himself but to the so-called Project Coordination Party, which then reported through the Deputy Chief Scientist. Between them the heads of project groups were responsible for by far the largest and most important part of the Establishment's programme, yet to them the Chief Scientist became a somewhat remote figure. Perhaps the organisation had become too large for Horton's particular style of management. He certainly preferred to work quietly and informally with a limited number of colleagues, rather than as a highly visible leader figure impressing his personality on the whole Establishment. Whatever these shortcomings, Horton had undoubtedly again put the Establishment on the right track, along which it subsequently travelled with conspicuous success. The basic structure continued unchanged for 15 years, throughout his term of office and that of his successor, and proved robust enough to adapt to many changes of circumstance - even Cecil Horton: Father of British Naval Radar xxxi including the absorption of another establishment (AGE) in 1959. His decision to go firmly for a project-oriented organisation set an example that many others were subsequently to follow . Even more than twenty years later Horton's basic precepts were still being rediscovered in other organisations, and propounded as new and fundamental truths. In 1951 he left ASE to become Director of Physical Research at the Admiralty, succeeding Sir William Cook, who had become Chief of the RNSS. He found the translation to headquarters uncongenial, and before long left to take up a new and successful career in industrial research, where he became a director of a well-known organisation manufacturing chemicals for agricultural and medical use. Cecil Horton possessed a rare ability to maintain the respect, enthusiasm and affection of his colleagues while allowing them free rein to exploit their creative talents and giving them unquestioning support when necessary. He never ceased to encourage closer under­ standing, cooperation and mutual respect between his scientific staff and the Naval officers with whom they had to work. After the war he emphasised that morale and leadership were just as important in the new Royal Naval Scientific Service as in the Navy itself, though in a subtly different way, and urged the Navy to pay as close attention to the one as to the other. Throughout his long career with the Admiralty he always took his responsibilities very seriously, and especially during those pioneering days of radar must frequently have suffered from frustration. Fortunately he was able to find solace in his long and happy marriage, and in his abiding love of music, shared also by his wife who had a charming contralto voice. He himself was a most accomplished performer with the violin (see Frontispiece), of truly professional standard, having been invited by Eda Kersey to play in her quartet, which was very highly regarded at the time . The musical evenings the Hortons arranged from time-to-time were a source of spiritual refreshment to fortunate colleagues as well as to the hosts themselves.

Acknowledgements

I am particularlyindebted to the late A. W. Rossfor his discerningrecollections of Horton in the early days of radar before the war. Thanks are also due to D.S. Watson, J.F. Coales, and other former colleagues, for helpful comments and advice.

References

1. F.A. Kingsley (ed.), The Applications of Radar andOther Electronic Systems in the Royal Navy in World War 2 (Macmillan, 1994). 2. F.A. Kingsley, op cit., Monograph 6 by P.G. Redgment. 3. D. Pritchard, The Radar War (PatrickStephens, 1989), p. 190et seq. Development and Installation of British Naval Radar - Some Significant Milestones

1928 HM Signal School applies for first patent on Radio­ Location in name of L. S. Alder. 1935 Feb. Watson-Watt demonstrates detection of aircraft by radio. Sep. Admiralty instructs HM Signal School to start develop­ ment of radar. 1937 May Preliminary trials of metric radar completed. Research on 1200 MHz begins. 1937 Sep. Development of warning radar (to become Type 79) settles on 43 MHz. 1938 Feb. Decision taken to develop equipment on 600 MHz using pulsed triodes. Mar . Type 79X, first experimental radar, installed in HMS Saltburn. Aug. Type 79Y, first operational radar, with 20 kW output, installed in HMS Sheffield, and in HMS Rodneyin October. 1939 Aug. Type 792, with 70 kW output, installed in HMS Curlew. Full production started, leading to a total of about 100 sets Dec. Development of Type 281 started on 90 MHz. 1940 Feb. Trials of 600 MHz rangefinder at AA Range, Eastney. Apr. HM Signal School instructed to design and produce 200 sets of Type 282 (600 MHz) . June Sea trials of 600 MHz radar in HMS Nelson. HM Signal School instructed to design and produce sets for fitting on all main armament and high-angle directors. 700 sets ordered. Type 286 (RAF 200 MHz ASV radar with fixed masthead antenna) started to be installed in large numbers in destroyers and smaller ships. Oct. Type 281 installed in HMS Dido. Full production started, leading to a total of about 80 sets. Nov. Signal School party visits Swanage to assemble copy of 'breadboard' TRE 3000 MHz (S-band) radar in a trailer, followed by preliminary trials against naval targets using TRE experimental equipment.

xxxiii xxxiv Development and Installation of British Naval Radar

Dec. Decision to proceed immediately with the design of a 10- em radar for convoy escorts. Trials of first production gunnery sets in HMS King George V (Type 284) and in HMS Southdown (Type 285). 1941 Mar. Trials of first prototype 5 kW S-band naval radar (Type 271X) in HMS Orchis. Twelve prototypes completed, and a further 12 in hand. Initial production order placed for 100 sets. Versions for destroyers and large ships (Types 272 and 273) followed in July. First Type 79B, with single antenna, fitted in HMS Hood. Apr. First multiple installation in a capital ship. Type 281 and eleven 600 MHz sets installed and commissioned in HMS Prince of Wales. May First Type 290, interim replacement for Type 286 with 50 kW output, installed in HMS Aurora. July Mobile trailer NT271X at Dover for coast defence. Resulted in Army conversion as CD No 1 Mark 4. Sep. 32 escort vessels at sea with Type 271; orders increased from 150 to 350. Experimental development in hand for higher power (70 kW) version (Type 271 Mark 4, to become 271Q and 273Q), also for yet higher-power (500 kW) version (Type 272/273 Mark 5, to become 276/277). Development begun for Type 274 5-band main-arma- ment gunnery set of similar power. Nov. Prototype Type 271/272/273P delivered; order for 1000 sets . Late First installation of Type 281B with single antenna. 1942 Early Development started of S-band gunnery set for high- angle directors (Type 275) Apr. Work started on close-range auto-follow gunlaying radar on 10000 MHz (X-band) (Type 262). May Trials with prototype 271Q (70 kW 5-band) in HMS Marigold, followed in July by 273Q in HMS KingGeorge V. Aug. First installations of Types 284P and 285P, with beamswitching for blind fire and common antenna for T/R. Late Initial work towards new fighter direction radar (Types 294,295). End First fitting of Type 291, final replacement for Type 286 with 100 Kw output. End Types 271/272/273P: delivery of 1000 sets complete. Dec. Development contract placed on EMI for Type 262. 1943 Mar. 500 KW 5-band radar (Type 277T) installed in trailer cabins for coastal defence. Development and Installation of British Naval Radar xxxv

Apr. Trials of seagoing version (Type 277X) in HMS Saltburn. Trials of Type 276 in HMS Tuscan followed in November. Mid PPI displays start to be installed in large numbers on most warning radars, reaching 5000 by war's end. Aug. Trials of prototype Type 293 5-band target-indication radar in HMS Janus . 1944 Progressive installation of Action Information Centres in most classes of ship. Mar. Trials of first production Type 277 in HMS Campania, followed by extensive installation of Type 277 in the Fleet. Revised development plan for fighter direction radar (Types 980/981). Aug. First installation of submarine radar Type 267W (Type 291 with additional X-band facilities) in HMS Tuna. Late Type 274 S-band gunnery radar installed on main armament directors in large ships. Late First installation of Type 262 X-band close-range blind­ fire radar. 1945 Early First installation of Type 275 5-band high-angle gunnery radar. Feb. General installation of Type 268 X-band warning and navigational radar in Coastal Forces. Type 293M began to replace Types 276 and 293 for target indication. Apr. Types 277P and 293P began to replace Types 277 and 293M. Mid Introduction of Type 281BQ, with addition of continuous antenna rotation. Late First installation of Type 960, replacement for both Type 79 and Type 281, in HMS Vanguard. Notes on the Contributors

J.F. Coales, CBE, F Eng, FRS. Born in 1907, Professor Coales joined Admiralty service in 1929 after graduating from Cambridge University. After original work on radio direction-finding, he transferred to developments in ultra-short wavelength radar and communications in 1937. During World War 2 he was in charge of research and development of Naval gunnery radar. Subsequently he returned to Cambridge as Professor of Electrical Engineering. He was elected President of the Institution of Electrical Engineers for 1971-2 and Honorary Fellow in 1985. Similar posts were held in international organisations concerned with automatic control systems and instrumentation. Awarded an OBE in 1945 and a CBE in 1974, he was elected F Eng in 1967 and FRS in 1970. Currently he is Emeritus Professor of Engineering at Cambridge University.

C.A. Cochrane, MA FInstP, CEng, MIEE. Born in 1919, C.A. Cochrane graduated from Glasgow University in mathematics and natural philosophy. He joined HM Signal School in August 1940 and was almost immediately involved in developing and introducing into Naval service the world's first operational centimetric wavelength radar. This was the Type 271 anti-submarine radar, operating on 3000 MHz, for installation on convoy-escort vessels. He continued to work on the development of centimetric warning radar for the duration of the war. In the early postwar years he did further work on microwave developments in an industrial research laboratory, where he was the inventor of the Cassegrain antenna for radar applications. Subsequent appointments were as Director of the Tube Investments Technological Centre, and later as Head of Division of Pollution Control in the Environment Directorate of the Organisation for Economic Cooperation and Development in Paris .

F.M. Foley, BA, MSc, MIEE. F. M. Foley graduated from Trinity College, Dublin, in 1937, followed by a year researching the physics of very thin metal films. He joined the Valve Division of HM Signal School in 1938, first working on the design of transmitter valves, later on receiving-valve applications and the achievement of very high valve reliability. In 1948 he transferred to the Seaslug radar project, working on the development of displays and ranging circuits. In 1954 he became Head of the Valve

xxxvii xxxviii Notes on the Contributors

Division; he later aided the development of thin-film microelectronics. From 1970-2 he was in charge of the Civil Marine Navigation Aids Division, before becoming Assistant Director, Post Design Services, in the Establishment.

H. D. Howse served at sea in the Royal Navy throughout World War 2, latterly as a specialist navigator. In 1958 he took early retirement as a Lt-Cdr, and became a curator at the National Maritime Museum at Greenwich from 1963 until 1982. He was Clark Library Professor of the University of California, Los Angeles, for the academic year 1983 to 1984. His published works include: The Sea Chart (with Michael Sanderson), 1973; Greenwich Timeand the Discovery of Longitude (1980); and Radar at Sea - The Royal Navy in World War 2 (1993). He was awarded a DSC and an MBE for his services at sea in World War 2 and the Korean War, respectively.

F.A. Kingsley, BSc, CPhys, FInstP, CEng, FlEE (editor) joined HM Signal School from Birmingham University in July 1941. Until 1945 he was engaged mainly in electronic-warfare projects, including technical planning of radar countermeasures activities as part of the Navy's contribution during the assault phase of the Normandy invasion in 1944. Postwar he was engaged in original radio-propagation research, electronic-warfare concepts and communications-systems develop­ ments. He became Head of the Communications Division of the Admiralty Surface Weapons Establishment in 1961, with the primary task of modernising the Royal Navy's ship and submarine communica­ tions . During this period he served on a number of inter-Service, NATO and CANUKUS communications systems Working Parties. He was a member of the original Space Research Committees of the Royal Society, and of a Cabinet Office Committee on Satellite Communications. In 1965 he was appointed as an Assistant Director in Central Staffs, Ministry of Defence.

R. A. Laws, MBE, BSc, FlEE, RNVR. Originally qualifying as a chartered accountant in 1939, R. A. Laws was mobilised as a member of the RNV(W)R in August of that year. He was commissioned as a Paymaster Sub-Lt in October 1940, and then appointed to the Special Branch, RNVR for radar duties in January 1941. He was mentioned in dispatches in 1944. On demobilisation in 1946 with the rank of Lt-Cdr, he joined the BBC research department. He gained his BSc from Sheffield University in 1950. He then held engineering appointments with Metropolitan-Vickers, GEC, CEGB and Marconi Underwater Systems. He was appointed FlEE in 1946 and awarded an MBE in 1986. Notes on the Contributors xxxix

B.W. Lythall, CB, MA. B.W. Lythall joined HM Signal School in 1940 after graduating from Oxford University, working initially on the development of the first operational centimetric radars. He then worked on microwave systems throughout the war, subsequently specialising in antenna design. In 1953 he moved to the Admiralty Research Laboratory to develop new methods of underwater acoustic detection. In 1957 he was appointed Assistant Director of Physical Research at the Admiralty. From 1958 he was Deputy Chief Scientist at the Admiralty Signal and Radar Establishment. In 1964 he was appointed to the Admiralty Board as Chief Scientist, Royal Navy, serving until 1978. He was also Deputy Controller of the Navy for Research and Development until 1971, when he became Deputy Controller, Establishments and Research, in the Procurement Executive. In 1978 he became Director of the NATO Saclant ASW Research Centre at La Spezia. He was awarded a CB in 1966.

A. M. Patrick, CEng, MIEE. In 1939 A. M. Patrick was mobilised as a member of the RNV(W)R and served initially in the South Atlantic. Commissioned in 1940, he gained experience as a radar officer during ship-fitting duties at HM Signal School and at Sherbrooke House, Glasgow, before being appointed Port Radar Officer, Rosyth, in 1941. In 1944 he became Base Radio Officer, Sydney, Australia. Here the roles of Port Radar Officer and Port Wireless Officer were combined for the very first time. Shortly before the war ended he was Fleet Radar Officer, British Pacific Fleet, with the temporary rank of Commander. Subse­ quently he served in HMS Collingwood on planning and personnel duties connected with the formation of the new Electrical Branch of the Royal Navy. From 1946 to 1952 he headed the newly formed Naval Radar Section of the Marconi Company, before serving as Assistant Electrical Engineer-in-Chief (Trials) in the Royal Canadian Navy from 1952 to 1955. He later held successive senior marketing appointments with Decca Radar Ltd and the Plessey Co.

B. G. H. Rowley, MA, C Eng, FIEE. After graduating from Oxford in 1939, B.G. H. Rowley joined HM Signal School to work on radar development. He was seconded to the Staff of C-in-C, Home Fleet, from May 1940 till April 1942, at Scapa Flow. He then served as a Lieutenant (Special Branch) RNVR in the USS Gleaves on North Atlantic convoy­ escort duty as Radar and Sonar Observer. In late 1942 he was posted as Staff Radar Officer, British Naval Staff, Washington, DC. Postwar appointments included that of US resident representative for Marconi's Wireless Telegraph Co Ltd, New York (1950-4), Manager of the Company's Maritime Division, England (1954-7); with the Canadian Marconi Company, Montreal (1957-60); with the English Electric Company, London (1960-3); with the North East Training Council xl Notes on the Contributors

(1963-5); as Careers Adviser and Industrial Liaison Officer, Woolwich Polytechnic (1965-9); with the International Labour Organisation in Chile (1969-70); and with the University of Manchester Careers Advisory Service (1971-82). j. S. Shayler, BSc, FlEE. J. S. Shayler graduated from Manchester University in 1938 and subsequently spent his whole career in defence research and development. He worked on Naval radar from 1938 to 1948 at HM Signal School (later Admiralty Signal Establishment). After this he was involved in sonar at the Underwater Detection Establishment; millimetre-wave CW radar at the Services Electronic Research Labora­ tory; aids to the operation of aircraft from carriers at the Naval , followed by automatic landing of aircraft at the Blind Landing Experimental Unit, both being located at the Royal Aircraft Establishment, Bedford; RAF and Army telecommunications at the Ministry of Defence; and finally as Head of Defence Research and Development, British Embassy, Washington, DC. He retired in 1978.