THE APPLICATIONS OF RADAR AND OTHER ELECTRONIC SYSTEMS IN THE IN WORLD WAR 2 photograph by Bassano & Vandyk Studios

ProfessorJohn Flavell Coales, CBE, F Eng., FRS

senior survivor of the prewar radar pioneers at HM Signal School and doyen ofwartime Naval gunnery radar The Applications of Radar and Other Electronic Systems in the Royal Navy in World War 2

Edited by F.A. Kingsley for the Naval Radar Trust

M © Naval Radar Trust 1995 Softcover reprint of the hardcover 1st edition 1995 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 WIP 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 978-1-349-13625-4 ISBN 978-1-349-13623-0 (eBook) DOI 10.1007/978-1-349-13623-0

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

10 9 8 7 6 5 4 3 2 1 04 03 02 01 00 99 98 97 96 95

Copy-edited and typeset by Povey-Edmondson Okehampton and Rochdale, England Contents

~~~~~ ~ List of Tables xiv Preface xv Development and Installation of British Naval Radar - Milestones xxi Notes on the Contributors xxv

PART I RADAR-SYSTEM APPLICATIONS IN WEAPON DIRECTION, WEAPON CONTROL, ACTION INFORMATION AND FIGHTER DIRECTION, 1935-45 Editorial Note 3

1 Weapon Direction in the Royal Navy, 1935-45 5 H. W. Pout Summary 5 Introduction 6 Sensors 7 Large ship sensors 10 Types 79 and 279 10 Types 280, 281 and 960 12 Small-ship sensors - 104m wavelength: Type 286 series, 290 and 291 16 5-band sensors - 10-cm wavelength 19 Specialised target indication radars 25 Weapon Direction 27 Early methods 27 Advances in weapon direction 29 Type 293 and Target Indication Unit Mark 2 30 Limitations of Type 293 and TIU 2 32 Type 992 and TIU 3 33 Future Staff Requirements for a gunnery direction system 35 Appendix 1: Extract from AFO 57 - Gunnery Terms - Revision 37 Appendix 2: Summary of Warning Radar Parameters 38 Appendix 3: Summary of Range Performance 42

v vi Contents

2 Weapon Control in the Royal Navy 45 H. W. Pout Section 1 Weapon Radar Development 45 Summary 45 Introduction 45 The Weapon Problem at Sea 46 Weapon-Control Systems 48 LA gunnery 49 HA gunnery, long range 50 HA gunnery, close range 51 The Applications of Radar to Weapon Control 52 The first phase: 50-cm (L-band) weapon radar appears, 1938-40 52 The second phase: improving the 50-cm radars, 1940-2 54 The third phase: the centimetric radar systems, 1941-5 65 The fourth phase: Lessons learned and proposals for the future, 1944-6 74 Future Systems 77 The early stages 77 Type 901 radar 78 The medium-range gunnery systems 82 The longer-term future - a footnote 82 Section 2 Weapon Systems and Their Performance 84 Summary 84 Introduction 84 The Prewar situation 85 The High-Angle Control System (HACS) 87 Case 1: The Basic HACS, Without Radar 89 Early improvements 96 Case 2: HACS with Radar-Ranging only 97 Remote Power-control (RPC) and LOS Stabilisation 99 Case 3: The Gyro Rate-Unit (GRU) 101 Case 4: Velocity Trigger (VT) Shell Fuzing 106 Case 5: Radar Type 275 and New Director Mark 6 108 Other errors 109 Medium and Long-range Anti-Aircraft Gunnery and the 'Ultimate' Design 112 Case 6: The 'Ultimate' Gunnery System 114 Radar 114 Fire-control 116 The Weapon 118 Target behaviour 119 Overall errors 120 Contents vii

Appendix 1: Explanation of Terms Used in Section 1 124 Appendix 2: Summary of Gunnery Radars manufactured or Developed from 1938 to 1946 127 Appendix 3: Notes on Aiming by Radar 130 Appendix 4: Explanation of Terms used in Section 2 136 Appendix 5: A Description of the HACS 138 Appendix 6: Extract from the LRS1 Staff Requirements and Cover Note 142

3 The Action Information Organisation 147 Cdr. A. E. Fanning Summary 147 Introduction 147 The Situation Prior to World War 2 148 The Introduction of Radar to the Fleet 150 Early Developments in Action Information Plotting 150 The Requirements for an Action Plotting Organisation 151 Plotting Developments in the Battle of the Atlantic 153 Formal Requirements for an Action Information Organisation 155 The Ala Training Centre 156 Getting the Ala to Sea 161 Appointment of the Co-ordinating Authority for the Ala 164 The Use of Radar in Navigating and Conducting Operations 166 Tailpiece 170

4 Fighter-Direction Materiel and Technique 173 Lt. Cdr R. S. Woolrych Summary 173 Introduction 174 The Birth of Fighter Direction in the RN 174 Formation of the Fighter Direction Training School 177 Fighter-Direction Developments at Sea 178 Further Developments and Improvements 181 Experiences in Other Theatres 183

PART II ELECTRONIC WARFARE DEVELOPMENTS, 1939-45 Editorial Note 189 5 Electronic Countermeasures in the Royal Navy 191 F. A. Kingsley Summary 191 Intoduction 192 viii Contents

The Beginnings of Radar Countermeasures in the Royal Navy 193 The First Operational Test of the Naval Jammer 195 The Radio War at Dover 196 The Naval Radar Monitor Station at Dover 197 Monitoring of E-boat Communications in the Channel 199 Shipborne Radar Jammers 201 The 10-Centimetre Radar Problem 202 Countermeasures Against Airborne Radar 210 XG2 Staff Developments 210 German Developments in Anti-Ship Guided Weapons 211 Preparations for the Invasion of Europe 214 Planning for the Allied Assault on France (Operation NEPTUNE) 216 The Diversionary Operations 218 Application of the Radar Countermeasures Plan 219 The Outcome 220 The Invasion of Southern France (Operation DRAGOON) 221 The End of the ECM War in Europe 222 10-centimetre Radar-Jammer Development 224 Developing ECM Effort Against Japan 225

6 High-Frequency Direction Finding in the Royal Navy: Development of Anti-V-Boat Equipment, 1941-5 229 P. G. Redgment Summary 229 Introduction 229 The Operational Problem 231 Outline of Radio OF Theory 233 Twin-Channel (Watson-Watt) CRDF 235 The Development of Shipborne HF OF 235 The site and the antenna system 236 Shipborne receiving equipment 240 Test equipment 241 Relation to USN developments 244 Other developments 246 Shore-Based HF OF 248 Antenna systems 249 Receiving equipment 249 Plotting and statistical methods 250 USN Navy shore-stations 252 German HF OF 253 Some Views with Hindsight 254 The relation between OF and 'Ultra' 254 Contents ix

Shipborne HF DF performance and operational needs 256 The contribution by the twin-channel CRDF 258 The German failure to appreciate the threat of shipborne HF DF 261 MF DF - an opportunity missed? 262 Conclusion

7 Review of German Maritime Radar Developments 267 F.A. Kingsley Summary 267 Introduction 268 The World's First Radar Experiments, 1904 268 Experiments with Pulsed Radar Systems in the Interwar Years 270 Early Radar Operational Requirements and Developments Naval radar systems 274 Luftwaffe radar systems that ultimately had Naval applications 276 A Note on Radar-System Nomenclature 278 The Operational Application of Gema Radar Systems, 1939-40 279 Shipborne installations 279 Shore-based installations 281 Early Air-Defence Radar Developments Having Maritime Applications 281 The Next Generation of Gema Radars 286 Shipborne systems 286 Coast-defence systems 289 Discovery of British em-Wave Radars, 1943, and Consequences 290 Naval developments 291 Land-based applications 293 Naval Radar Developments in the Decimetre Waveband, 1943-5 295 IFF Developments (Funkmesserkennung, FuME) 296 Passive Radar (Radar Search/DF Receivers) (Funkmessbeobachtungsempfanger, FuMB) 297 Conclusion 305

Appendix: Type Numbers of Radars in the Royal Navy up to 1945 309 Glossary 315 Select Bibliography 325 Index 331 List of Illustrations

1.1 Target Indicating Unit, Mark 2A, with Rangefinding Outfit RTB 31 1.2 Reliable detection range: simplified coverage diagrams against medium-sized bomber targets 43 2.1 Type 285, showing six 'fishbone' antennae on the high-angle director control-tower, ranging panel L12, and fire-control table 55 2.2 Panel L12 displays: (A) 6000-yd maximum range for close- range set; (B) 15000-yd maximum range for high-angle set; (C) 24000-yd maximum range for low-angle set; 57 2.3 Precision ranging system: (A) using calibration pips; (B) using a bright spot range-index on 10-cm low-angle radar 59 2.4 Auto-barrage unit with ranging panel L22 64 2.5 lO-cm high-angle radar equipment 69 2.6 STAAG twin-Bofors mounting with Type 262 installed on it 72 2.7 Diagrammatic layout of STAAG mounting (Mark 2) 73 2.8 Production prototype of Type 901 on stabilised antenna carrier 80 2.9 HAC table Mark 4 (a) side view; (b) rear view 88 2.10 Fuze-keeping Clock Mark 3 89 2.11 Rangefinder Director Mark 3 90 2.12 Director Mark 4 (GB)HA 101 2.13 Director Mark 5"'M HAlLA 102 2.14 Director Mark 6 HAlLA 103 2.15 Gyro Rate-unit Mark 2 104 2.16 Summary of results 124 2.17 Pulse-to-pulse fading of 3-cm radar signals (1500 pps) : (A) rapid fading; (B) long-period fading; (C) fading that exhibits a large 30 cis component; (D) taken with a conically- scanning set to show the effect of the 30 cis misalignment signal for comparison 132 2.18 High-performance radars, aiming errors (rms) 135 2.19 HACS ranging system 141 3.1 Maintaining the plot on an ARL Table in HMS Royal Sovereign during Combined Fleet exercises, 1937 149 3.2 The Skiatron projection display in the ADR, HMS Venerable, 1943 159

xi xii List of Illustrations

3.3 Layout of the AIO complex in and cruisers, 1944-45 162 3.4 Combined ADR and TIR in a light fleet carrier 163 5.1 Physical arrangement of Davis' jammer oscillator 195 5.2 Sixteen of the Type 91 radar jammer antennae of the Dover '2' Station complex 198 5.3 General arrangement of the RF head of a 1942-vintage crystal detector/video amplifier receiver 204 5.4 Side elevation of the 'Trumpet' type of detector/video receiver 205 5.5 The first modification of the GEC Type AB 2 receiver 206 5.6 Overhead view of the CV39-modified Type AB 2 receiver 207 5.7 External view of the mobile em-wave intercept vehicle 208 5.8 Schematic reconstruction of the coverage of the German coastal radar chain against Allied shipping 217 6.1 Framecoil S25B: sketch showing configuration of main components 238 6.2 Principle of sense-antenna balancing: (a) simplified diagram of sense-antenna system; (b) simplified equivalent circuit 239 6.3 Instrument set-up for measuring the resonant frequency of a mast and balancing the sense system 243 7.1 Illustration of Hulsmmeyer's concept of the shipborne 'Telemobiloscope' radar detecting an approaching target, as presented in his patent 269 7.2 The Small Wiirzburg radar for early warning against aircraft targets 272 7.3 The GEMA Seetakt surface-search radar. Early 60-cm version fitted on the rangefinder of the Admiral Graf Spee, the antenna being covered by a canvas screen 275 7.4 The Giant Wiirzburg radar for air defence (AA fire-control, GCI) and later coast defence 277 7.5 The Seetakt radar fitted on the foremast of the Bismark 280 7.6 The Seeburg coast-defence version of the Giant Wiirzburg 284 7.7 Schematic illustration of the 'Radattel' A/N bearing- determination principle 287 7.8 Illustrations of the output display using 'Radattel' 288 7.9 A Seetakt FuMO 27 mounted on the aft rangefinder on Prinz Eugen 289 7.10 The shipborne Berlin S (FuMO 81) radar antenna assembly using an array of four in-phase dielectric-rod elements to produce a horizontal beamwidth of 11°. Research on an eight-element array was in progress in 1945 292 7.11 The Metox search receiver: (a) front view; (b) internal view 298 List of Illustrations xiii

7.12 The Bali I search receiver antenna for U-boats, for use with the WAnz spectrum search receiver. It covered both horizontal and vertical polarisation, and in developed form could give an approximate azimuth bearing on horizontal polarisation 300 7.13 The 'Naxos' Search/DF RF head covering the 8-12-cm waveband, designated FuMB24 ('Cuba') 301 7.14 The 3-cm receiver RF head 'Miicke' (FuMB25) 302 7.15 The 'Spinning Naxos' receiver RF head (FuMB7) covering the 8-12-cm waveband 304 7.16 The pressure-tight Search/DF RF head 'Athos', covering Allied S- and X-Band shipborne and airborne radar systems, fitted on the U249, which surrendered at Portland immediately after the end of the war 306 List of Tables

1.1 Summary of Waming Radar Parameters 40 2.1 Roll and pitch characteristics 91 2.2 Case 1: kill probability (no radar assistance) 95 2.3 Case 2: kill probability (radar ranging) 98 2.4 Case 3: kill probability (with GRU well-adjusted and maintained) 105 2.5 Case 4: kill probability (VT fuzing) 107 2.6 Radar: errors in future-position (in yards rms), at future ranges (time-of-flight) 116 2.7 Fire-control: errors in future-position (in yards rms) at future ranges 117 2.8 The weapons: errors in future-position (yards rms) at future ranges 119 2.9 Target roughness of flight errors in future-position (yards rms) at future ranges 120 2.10 Summary of results: errors in future-position at future ranges 121 2.11 Probability of a hit: single-shot hit probability (Ph) as a percentage 122 2.12 Probability of a hit with 903 radar in place of 905 123 2.13 Summary of gunnery radars manufactured or developed from 1938 to 1946 129

xiv 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 40 or 50 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 all these 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. InJune 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 realisation 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

xv xvi 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 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, SeD, 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, that 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 author designate - a major act of faith that eventually proved justified when Radar at Sea was published at the beginning of 1993. The 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 incorporate 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 Preface xvii concerned with the application of radars in operational systems - for target indication, weapon direction, command-and-control, and fighter direction. It also includes the story of British Naval radar counter­ measures/ a technical history of HF DF (which, in conjunction with radar, made a most important contribution to the Battle of Atlantic) and an essay on parallel developments in German Naval radar over the same period. A companion volume deals with radar development.' It gives an overview of work in the Experimental Department of HM Signal School (later the Admiralty Signal Establishment), and describes each of the main prog­ rammes of radar equipment development, the underlying research and some of the problems of installation, operation and maintenance at sea. 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. Also, the Institutions 'Proceedings of the Communications Convention/ published in 1947 contains accounts of the development of Naval HF OF (inter alia), described in a monograph in the present volume. A few more individual papers were subsequently published in the Institution's journal and in other scientific and mathematical journals. xviii Preface

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 made of recollections of the few people then 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 discussed in more detail in the Bibliography.

ACKNOWLEDGEMENTS

Our first thanks must go to John Coales, without whom the project would never have been started, and to all the authors of individual monographs. The source material is now very diffuse, and a great deal of painstaking work has been necessary for each author to piece together as accurately as possible the various elements of the story. Alex Rae prepared the indexes for both volumes - as well as compiling a series of staff lists to be deposited in the Churchill Archive Centre. Derek Howse provided valuable reference material for several Appendices, notably those on the complex ramifications of radar type numbers and ships fitted; these appear in the companion volume, which also includes a collection of technical data sheets prepared by Alan Laws. 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 but it is impossible to mention 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 Establishment, Portsdown, Lieutenant­ Commander Bill Legg of HMS Collingwood and Lieutenant-Commander Peter Lee of HMO 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 go there themselves. His diligence in following up Preface xix many queries, and his own extensive knowledge and experience of wartime radar, have been invaluable. 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 firm 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; he has been an exemplary editor. 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 complete volume emerged in such good time after his appointment, and that its component parts were welded, with tact, persuasion and persistence, into a reas­ onably 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 pic, 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 (00.), The Development of Radar Equipmentsfor the Royal Navy, 1935-45 (Macmillan, 1994). 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 Rodney in October. 1939 Aug. Type 79Z, 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, Eastne y. 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 3,000 MHz (5-band) radar in a trailer,

xxi xxii Development and Installation of British Naval Radar

followed by preliminary trails against Naval targets using TRE experimental equipment. Nov. Decision to proceed immediately with the design of a 10­ cm radar for convoy escorts. Trials of first production gunnery sets in HMS King (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 . Type 281 and eleven 600 MHz sets installed and commissioned in HMS Prince of . May First Type 290, interim replacement for Type 286 with 50 kW output, installed in HMS Aurora. JuI. 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 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 S-band) in HMS Marigold, followed in July by 273Q in HMS King George V. Aug. First installations of Types 284P and 285P, with ­ switching 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 271/272f273P: delivery of 1000 sets complete. Dec. Development contract placed on EMI for Type 262. Development and Installation of British Naval Radar xxiii

1943 Mar . 500 KW S-band radar (Type 277T) installed in trailer cabins for coastal defence. 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 S-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. Mar. 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. Feb. 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

Commander A. E. Fanning, MBE, DSC, joined the Royal Navy in 1932 and served at sea, mainly in destroyers, throughout World War 2. He specialised in navigation in 1941, and later became Head of the Action Information Training Section at the Navigation School at Portsmouth (HMS Dryad). In 1960 he joined the Admiralty Compass Observatory, becoming Deputy Director. Later, when the Observatory was amalga­ mated with the Admiralty Surface Weapons Establishment (descended from HM Signal School) he was the Senior Naval Officer and Application Commander. He was awarded an MBE and a DSC for his services. He is the author of Steady as She Goes, the history of the Compass Department of the Admiralty.

H. D. Howse, MBE, D5C, served at sea in the Royal Navy throughout World War 2, latterly as a specialist navigator. In 1958 he took early retirement as a Lieutenant-Commander and took an appointment as a curator at the National Maritime Museum, Greenwich, from 1963 until 1982. He then became Clark Library Professor of the University of Cali­ fornia, Los Angeles, for the academic year 1983-4. His published works include The Sea Chart (with Michael Sanderson) (1973), Greenwich Time and the Discovery ofLongitude (1980) and Radar at Sea - The Royal Navy in World War 2 (1993). He was awarded an MBE and a DSC for his services.

F.A. Kingsley, BSc, CPhys, FlnstP, CEng, flEE, joined the Admiralty from Birmingham University in July 1941. Until 1945 he was engaged mainly in electronic-warfare projects, including technical planning in support of the Navy's contribution to radar countermeasures in the assault phase of Operation OVERLORD. Subsequently he was engaged in original radio-propagation research, electronic-warfare concepts and communications-systems developments. He became Head of the Communications Division of the Admiralty Surface Weapons Establish­ ment in 1961, with the primary task of modernising Royal Naval ship and submarine communications. 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 of the Ministry of Defence.

xxv xxvi Notes on the Contributors

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.

H. W. Pout, CB, aBE, BSc (Eng), FCGI, flEE, FBIM, graduated from Imperial College, London, in 1940 and immediately joined HM Signal School, working initially on direction-finding. Subsequently he joined the Gunnery Radar Group (under J. F. Coales), then in the early stages of expansion. From then until 1954 he specialised in gun and then guided­ weapon radar-control systems. This was followed by four years in Naval operational research, one year at the Imperial Defence College and five years as Head of Guided Weapons Projects, Admiralty. In 1965 he became Assistant Chief Scientific Adviser (Projects) in the Ministry of Defence in 1969; Director of the Admiralty Surface Weapons Establish­ ment (descended from HM Signal School); from 1973 he filled a number of Deputy Controllership appointments in the Ministry of Defence, the Army Department and the Air Force Department. Following retirement from the Civil Service he was engaged in private consultancy work for a period, before undertaking a final appointment with GEe. He was awarded a CB and an aBE for his services.

P. G. Redgment, MA, MIEE, MRIN, graduated from Cambridge in 1941 after reading mechanical sciences. He joined the Direction-Finding Section in the Experimental Department of HM Signal School, becoming Head of the Shore DF Section in the (renamed) Admiralty Signal Establishment in 1943. In 1944 he became Head of the reorganised DF & Y (rad io intercept) Division. After the war he was first engaged in the development of UHF communications systems, before transferring to underwater-systems developments at the Admiralty Underwater Weap­ ons Establishment, Portland.

Commander R. S. Woolrych, aBE, RN. At the outbreak of war R.S. Woolrych was an officer in the Seaman Branch of the Royal Navy. From Notes on the Contributors xxvii

1943 he specialised in fighter direction from aircraft carriers. Postwar appointments were mainly concerned with Naval research and develop­ ment, and operational research. He took early retirement from the Navy in 1954, and then studied architecture for five years as the basis for a second career. He was awarded an aBE for his services to the Navy.