Medmenham: Anglo-American Photographic Intelligence in the Second World War VOLUME 1 Submitted for the Degree of Doctor of Philosophy At the University of Northampton 2019 Paul David Theo Stewart © Paul David Theo Stewart 2019 PhD. This thesis is copyright material and no quotation from it may be published without proper acknowledgement. ABSTRACT The role of photographic intelligence during the Second World War at Royal Air Force (RAF) Medmenham and its predecessor at Wembley is investigated in this thesis. The development from 1939 to 1945 of photographic reconnaissance and photographic interpretation is examined. The growth of the Central Interpretation Unit (CIU) at Medmenham and its change to the Allied Central Interpretation Unit (ACIU) in 1944, with the arrival of a significant American influx is investigated. Medmenham is compared with Bletchley Park using an organisational lens to reveal similarities and differences in the growth and development of these two centralised intelligence organisations. The thesis then explores four case studies: Operation Sealion, the Nazi planned invasion of Britain in 1940, Operation Millennium, the first 1,000 bomber raid of the war in 1942, Operation Chastise, the Ruhr dams raid in 1943 and Operation Epsom, the first large scale operation after D-Day to capture Caen in June 1944. The primary methodology employed is a detailed examination of the photographic interpretation reports produced by Wembley and Medmenham during the operations. The core of the methodology used in this thesis, is an individual examination of every photographic interpretation report produced for each of the case studies. The thesis provides an innovative interpretation of the role and importance of photographic intelligence during the Second World War. It therefore makes an original contribution to intelligence history. i DEDICATION To all those that served at Royal Air Force Medmenham in the Second World War. ii ACKNOWLEDGEMENTS This thesis or the germ that developed into it started 40 years ago, when on a photographic interpretation course, I was introduced to the work of my Second World War predecessors at RAF Medmenham, by Wing Commander Mike Mockford. He was the driving force within the Medmenham Association to set up the Medmenham Collection, museum and archive. I owe Mike Mockford and his successors a debt of gratitude for all their help, patience, advice and guidance as well as allowing me access to the riches within the Medmenham Archive. I have to acknowledge the assistance of the Air Historical Branch, who provided me with accommodation and easy access to the AIR series of files for my last six months in the Royal Air Force. Seb Cox, Group Captain Steve Lloyd and the team at the AHB were ever patient with my questions and copious demands for more and more files from the TNA. That period in 2013 provided the bedrock on which this thesis is based. I also owe a debt of gratitude to the United States Air Force Historical Studies Research Office on Bolling Air Force Base, Washington DC. They provided me with accommodation and access to the US Army Air Force archive and were ever helpful with my numerous requests, for which I thank Richard Wolf and his team. I am also grateful for the often anonymous but greatly appreciated help of numerous staff at The National Archives at Kew; the Science Museum Archive near Swindon and RAF Hendon Museum Archive. My thanks also to Robert Owen the 617 Squadron historian, who pointed me to copies of the missing Medmenham Rhur Dams reports within TNA. Then there is the sage advice, guidance and gentle direction from my supervisory team of Jim Beach, Paul Jackson and Claire Hubbard-Hall. My main supervisor Jim Beach warrants a special mention for all his hard work and encouragement, in so many areas of my research journey, but especially for turning my 40 years of service writing into something approaching English! I would also like to thank my examiners Martin Alexander and Drew Gray. Then finally, but by no means least, my very long-suffering wife, Jean. She has lost a dining room for 5 years and found herself, via commenting and copy-editing so many drafts, an expert on RAF Medmenham. To her my gratitude knows no bounds. iii Table of Contents VOLUME 1 Chapter Page 1. Introduction 1 2. Organisation 29 3. Sealion, 1940 70 4. Strategic Bombing, 1942-1943 108 5. Normandy, 1944 150 6. Conclusion 191 Annexes Annex Page A. List of CIU and ACIU Sections 198 B. Medmenham Sections 199 C. British - American - German Reconnaissance Organisation 216 D. British - American - German Aerial Cameras 219 E. Transcript of Flying Officer Maurice Longbottom 223 Memorandum F. Transcript of Sydney Cotton Memorandum 233 G. The Wild A5 Stereo Autograph 235 H. Map 5 Medmenham and Associated Bases 238 I. Medmenham Manning, Production & Sortie Figures 239 J. Bletchley Park Organisation 1940 – 1944 243 K. Bletchley Park Processes and Huts 244 L. Map 6 Spitfire Photographic Sortie Ranges 249 iv Annex Page M. Photographic Interpretation Reports 1 to 100 250 N. Map 7 Invasion Ports and Sealion Plan 263 O. Analysis of Cologne Reports 264 P. Analysis of Operation Chastise Reports 275 Q. Map 8 The Normandy Campaign and Operation Epsom, 286 Front 17 – 30 June 1944 R. Map 9 Daily Railway Report 45, Map of Nord System 287 with Original Annotations S. Stereoscopes 288 VOLUME 2 Appendixes Appendix Page 1. Sealion - Transcribed Photographic 291 Interpretation Reports 2. Strategic Bombing - Transcribed Photographic 323 Interpretation Reports 3. Normandy - Transcribed Photographic 361 Interpretation Reports 4. Master French Railway 416 System Maps v Bibliography Page Bibliography 423 Tables Table Page 1. Heston Units, Name Changes, September 1939 40 to November 1940 2. Photographic Interpretation Unit, Name Changes 47 1939 – 1945 3. Organisation of PIU Wembley and CIU/ACIU Medmenham 53 4. Formation of CIU/ACIU Sections by Date 58 5. Comparison of Bletchley Park Size / Medmenham Size, 64 1939 to 1945 6. Report Totals on Barges and Shipping, 16 May 85 to 2 October 1940 7. Report Totals on Aerodromes, 16 May to 2 October 1940 87 8. Sealion Invasion Ports, Barge Reports, 16 May to 89 14 October by Week 9. Sealion Invasion Ports, Barge Count and Coverage 16 May to 90 14 October by Week 10. Sealion, Barge Reports, 1 to 30 September by Location 92 11. Sealion, Barge Reports and Counts 1 to 30 September 93 by Location vi Table Page 12. Sealion Invasion Ports, Barge Reports and Counts 1 to 95 30 September 13. Photographic Spitfire Sorties for September 1940, 98 Targets Tasked 14. Spitfire Sorties for September 1940, Targets Photographed 100 15. Medmenham CIU Reports covering Cologne, 23 March to 120 10 August 1942 16. Bombing Raids on Cologne, January to May 1942 126 17. Medmenham Reports on Ruhr Dams, February to May 1943 135 18. Post Raid Reports for Operation Chastise 143 19. Total Reports by Medmenham, 24 June 1944 168 20. Total Targets Reported on by Medmenham in Daily Airfield, 172 Daily Railway and Daily Army Report by French Region 21. Coverage of Daily Airfield Reports on France 175 during Operation Epsom 22. Daily Army B Series Reports, Tabulated by French Region 179 during Epsom Period 23. Daily Railway Reports, Tabulated by French Region during 185 Epsom Period 24. Industries Section Specialist Teams 201 25. RAF Photographic Reconnaissance Units and Squadrons, 216 November 1940 to May 1945 26. US Army Air Force Reconnaissance 217 vii Table Page 27. Luftwaffe Reconnaissance Squadrons 218 28. Camera Development in the RAF 1939 to 1945 219 29. Camera Ground Coverage 220 30. USAAF Aerial Cameras 221 31. Luftwaffe Aerial Cameras 222 32. Medmenham Reports, covering Cologne from 23 March to 264 10 August 1942, with Area Covered 33. Medmenham Chastise Reports, February to May 1943 275 with Area Covered Graphs Graph Page 1. RAF Medmenham Manning November 1942 to April 1945 239 2. Interpretation Reports 1940 to 1945 49 3. Photographic Prints Produced 1941 to 1945 57 4. Sorties Received at Medmenham 240 5. Sorties Received at Medmenham in 1944 241 6. Prints Received at Medmenham 242 Pictures Picture Page 1. Boulogne 18 September 1940 96 viii Picture Page 2. Mosaic of Cologne produced to accompany 130 Medmenham Report K.1333 3. Photograph of Moehne Dam Model at Medmenham 140 4. Continuous Film Processor 214 5. Multi-Printer 214 6. RAF Medmenham 215 7. Wild A5 at Wembley 1939/1940 235 8. Type B Stereoscope 288 9. Stereoscope Universal Type SV-3 289 10. Size Comparison Type B and SV-3 Stereoscopes 290 Maps Map Page 1. Overlord Landing Beaches 6 June 1944 153 2. French Map by Region 170 3. Convoy Shelter Positions 178 4. Ground Situation 17 June to 30 June 1944 180 5. Medmenham and Associated Bases 238 6. Spitfire Photographic Sortie Ranges 249 7. Invasion Ports and Sealion Plan 263 8. The Normandy Campaign and Operation Epsom, Front 17 – 30 286 June 1944 ix Map Page 9. Daily Railway Report 45 Map of Nord System with 287 Original Annotations x Abbreviations 2 TAF 2nd Tactical Air Force 3D Three-dimensional ACAS (I) Assistant Chief of the Air Staff Intelligence ACIU Allied Central Interpretation Unit ADI Assistant Director Intelligence ADI (Photo) Assistant Director Intelligence for Photography AFHSO Air Force Historical Studies Office (United States) AGPIU Army Group Photographic Interpretation Unit AHB Air Historical Branch AI 1 Air Intelligence 1 AI 3 Air Intelligence 3 ALG Advanced Landing Ground AOC Aircraft Operating Company AP Air Publication APIS Army Photographic Interpretation Section BEF British Expeditionary Force