by Hitler's Revenge Weapons- The Final Blitz of London (retail) (epub)
The sources of information on the burgeoning German interest in military rockets were many and various, but fell largely into three categories, each with its own particular value in content and timing. There was human intelligence, ‘HUMINT’, derived from diplomatic exchanges, spies, friendly agents, random documents or simply conversations overheard, typically at prisoner of war (PoW) centres, ‘bugged’ for the purpose. Then there was ‘SIGINT’ the interception of radio signals at many listening posts, particularly from the highly-secret Government Code and Cypher School (GC & CS), at Bletchley Park. If considered potentially useful, every effort would be made to validate their authenticity and dispense with deliberate, inherently harmful misinformation before such inputs were analysed, collated and passed to relevant ‘customers’, or stored for future reference.
The third major source of invaluable information, often triggered by HUMINT or SIGINT, was air reconnaissance, in three primary forms: Photographic Recce (PR), Fighter Recce (FR) and Visual Recce (Vis Recce). PR aircraft, typically RAF Spitfires and Mosquitos, together with a variety of USAAF aircraft, usually operating singly at high or medium levels (when cloud cover allowed), using vertical or oblique cameras for mapping, area cover and pinpoint photography. These aircraft were stripped of all equipment not vital to the role, such as weapons, to enable them to fly as high and as fast as possible, thereby giving them some immunity against enemy fighters and anti-aircraft guns.
FR aircraft, such as the RAF Spitfires and Mustangs and USAAF P-38 Lightnings, were high-performance fighters, equipped with cameras optimised for low-level oblique photography; for their survival, they relied on surprise, high speed, manoeuvrability, tactical routing – and (for those suitably equipped) their guns. The retention of weapons also allowed them, if authorised, to attack high value targets of opportunity – but rarely at the expense of their primary role, that of gleaning detail of the assigned or opportunity targets, visually and with close-range oblique photography. Incidentally, all military pilots, whatever their role, were expected to report sightings of potential targets, or indeed any other information which might be of use to intelligence staffs, throughout their sorties.
Until 1939 PR had been the responsibility of the Special Intelligence Service (SIS) within MI5, its rapid development driven by such men as Squadron Leaders F.C.V. Laws, a PR veteran of the Royal Flying Corps (RFC), and W.H.G. Heath at the Air Ministry, P.J.A. Riddell of Bomber Command, and a freelance civilian aerial photographer, Frederick Sidney Cotton. They laid the foundations for a small photographic interpretation (PI) section, comprising three officers, who draw information from PR sorties flown by Blenheim, Hudson, Lockheed 12A and, latterly, Spitfire aircraft, operating covertly from RAF Heston, under the cover name of No.2 Camouflage Unit. In January 1940 this became the Photographic Development Unit (PDU), and six months later the Photographic Reconnaissance Unit (PRU), under the operational control of Coastal Command, evolving into a number of Spitfire flights, based at different locations in the UK until, at the end of 1940, No.1 PRU took up residence at RAF Benson, Oxfordshire, where it remained throughout the war. Information gathered by aircrew operating far into the continent of Europe went first to the Photographic Interpretation Unit (PIU), which started life at Wembley before moving to the more spacious Danesfield House, Medmenham, in April 1941, where it became the Central Interpretation Unit (CIU). There it was analysed and collated before being presented to intelligence staffs and, where appropriate, to the relevant battle managers.
Head of the Technical Control Section of CIU was Wing Commander Douglas Kendall, a pre-war aerial survey pilot, who held the highest security clearance and had access to all intelligence sources. From the start the CIU nurtured a rapidly increasing band of PIs and reprographic staff at Medmenham and model-makers at Phyllis Court, Henley. Inevitably, the CIU became deeply involved in the search for definitive evidence of German rockets and flying bombs, their trials, production centres, and deployment sites. The CIU continued to expand rapidly as the war progressed, absorbing the Bomber Command Damage Assessment Section and the Night Photographic Interpretation Section of No.3 PRU, at RAF Oakington, and, as more Americans joined the staff, the CIU became the Allied Central Interpretation Unit (ACIU) on 1 May 1944. At peak strength 1,700 personnel served at Medmenham, sifting through a daily input of 25,000 negatives and 60,000 prints, and by 1945 the ACIU had generated a library of 5,000,000 prints and 40,000 reports. This was big business – and it paid off.
This chapter will deal later with the many invaluable contributions made by the aircrew and ground specialists involved in wartime air reconnaissance, in discovering the Vergeltungswaffen and in the ensuing campaign against them. First, however, it would be instructive to review the many diverse inputs on the two weapons and how they were dealt with by the hierarchy in the British scientific and technical communities in what became a protracted, often fractious, debate on the feasibility of the technology alluded to and the validity of the intelligence derived.
The author could find no record of London reacting positively to clues relating to work on offensive rockets underway at Kummersdorf throughout the 1930s, but the intense activity at Peenemünde in the second half of the decade could surely not have gone unnoticed, especially when so much effort was devoted to the site’s security. In his 19 September 1939 speech at Danzig, Hitler himself hinted openly that Germany was developing weapons with which they themselves could not be attacked. Then, in early November 1939, came the ‘Oslo Report’, in which British intelligence staffs were offered details of the evolutionary work by German scientists on radar, magnetic mines and the new aerial weapons being developed at Kummersdorf and Peenemünde. The report, written by the disillusioned German mathematician and physicist, Hans Ferdinand Mayer, came in a package which included a small glass tube, contents unknown, but part of a prototype proximity fuse. It seems that the information therein was largely discounted by many in London, as an elaborate hoax designed to mislead the Allies.
From the start of the war a sporadic stream of information began to emerge from Poles forced to work at Peenemünde, and later from the Polish Underground at various locations, with one partisan reporting a conversation with a drunken German airman in Königsberg, who boasted that Germany had a new weapon, which would ‘conquer the world’. This information was passed to Warsaw and on to London, which requested further investigations by the Poles embedded at Peenemünde. This elicited the information from Polish ‘volunteers’ for latrine duty who, in their wanderings with impunity abound the camp, confirmed the presence there of a ‘small, pilotless aeroplane’. Other occupied countries also contributed; Major V.L.U. Glyth, Royal Danish Army, secreted a parcel of information on to the last diplomatic train to leave Copenhagen at the start of the German occupation which contained details of the latest German dispositions in the country. He continued to pass intelligence to the British, primarily via Danish seamen and a clandestine radio network throughout the war and, by the winter of 1942/43, his inputs were containing strong evidence of intensive rocket and flying bomb activity at Peenemünde.
Neutral countries also became involved. In December 1942 the SIS Station Chief in the Stockholm office reported a conversation overheard by a new agent, Aage Andreasen, a neutral armaments engineer, in a Berlin restaurant between Professor Fauner, of the Berlin Technische Hochschule, and a German weapons engineer, Stephan Szenassy, concerning a rocket that was being developed with a range of 200 kilometres, a warhead of 5 tons and an automatic steering system. This caught the eye of R.V. Jones, who was now both the scientific adviser to the SIS and Assistant Director Intelligence Science (ADI Science) at the Air Ministry. Dr Reginald Victor (‘RV’) Jones had left Oxford with a first-class honours degree in physics, joined the Royal Aeroplane Establishment in 1936 and the Directorate of Scientific Intelligence in the Air Ministry in 1939 and became a very significant player in the fractious debate on the two missiles. Then, in January 1943, another agent from Sweden confirmed the acti
vity at Peenemünde, specifically that rockets were being tested there and that a large airfield was also being constructed on the north-east corner of the Usedom, all of which were then featured in the SIS Digest, dated 8 February 1943. Such reports, seen by the appropriate departments in the SIS and the War Office, were now coming in thick and fast, and could not be ignored.
Danesfield House, Second World War home of the Central Interpretation Unit (CIU). (Author)
In London Professor Lindemann, who had been raised to the peerage in 1941 to become Lord Cherwell, was Prime Minister Churchill’s Chief Scientific Adviser throughout the war. A somewhat haughty, self-opinionated but well-educated physicist, Cherwell had studied in Germany at Darmstadt and Berlin universities; he denounced much of the evidence on offer, suggesting that the ‘long, cylindrical objects’ photographed at Peenemünde were no more than ‘some sort of balloon’. He and Dr A.D. Crow, the chief rocket expert at the Ministry of Supply, claimed that the rocket envisaged would have to be powered by solid fuel, most probably cordite, because the technology which would allow the use of liquid fuel had yet to be developed and that, therefore, the missile would be far too heavy to reach London from launch sites on the continent. Nor did he believe that the Germans had the expertise to produce an effective flying bomb, able to threaten the British capital. His friend, R.V. Jones thought otherwise but, to his dismay, little immediate action was being taken to follow up on all the foregoing leads, including the Oslo report, at least until a further piece of HUMINT emerged on 22 March 1943. This came from Squadron Leader Denys Felkin, who listened in to a ’bugged’ conversation between two German generals, General Ritter von Thoma and General Ludwig Crüwell, at the Trent House PoW camp at Cockfosters, in North London. There, von Thoma recalled seeing rockets at Peenemünde, some eighteen months before, which were said to be nearing operational status – and wondered why they were not raining down on London already.
This steady accumulation of intelligence finally convinced the War Office that the Chiefs of Staff should be advised of the potential threats, and this was done in a consolidated report on 11 April 1943. They in turn believed Churchill should be informed, and that a single individual should head a review of all available evidence on the missiles which now had to be anticipated, and so it was that, on 20 April 1943, Major Duncan Sandys was called on to head comprehensive studies of German long-range rocket developments. His remit included the identification of the weapons, how they were powered, controlled and launched, where they were being produced, tested and likely to be deployed, concentrating on an area of the continent within 130 miles of London and Southampton. All intelligence sources would be made available to him and his investigations accorded the highest priority.
German rocket and flying bomb research and production units. (Author, Courtesy HTM Peenemünde)
Duncan Sandys MP became Financial Secretary to the War Office in 1941, following service as an artillery officer with the British Expeditionary Force in 1940. Thereafter, he was involved in operational evaluations of anti-aircraft rockets until released from active duty after a traffic accident. He was favoured by Prime Minister Winston Churchill (his father-in-law) but not by Lord Cherwell, whose preference for this important appointment had been R. V. Jones. This did nothing to deter Sandys from getting on with the job he had been given, assisted by an old friend and military adviser, Colonel Ken Post, the two working hard to get to the truth on the rocket and flying bomb, and how best to defend against them. They began by enlisting the help of the Joint Intelligence Committee (JIC), which comprised the intelligence heads of the three services, under a permanent chairman from the Foreign Office. Also, they took guidance from the SIS on the likely validity of the relevant intelligence gathered so far and welcomed help from MI10, the Military Intelligence Germany (Technical) Branch, and the PoW section. The CIU at Medmenham was tasked to review all the photographs of north-west France, within a 130 mile radius of London, looking for any evidence of long-range gun emplacements, flying-bomb or rocket launch sites and, where cover was lacking, request the PRU be tasked to fill in the gaps. Two new cells were set up at the CIU, one to deal with Peenemünde, under the eyes of the RAF PI, Flight Lieutenant André Kenny, the second covering north-west France run by the Army PI, Captain Robert Rowell. With such inbuilt tensions at the top, it would not have been surprising if some critical, ‘raw’ information had failed to flow freely in all directions.
In the War Office Dr Charles Frank and Captain Matthew Pryor, of MI14, which dealt with German military matters, had taken an unofficial short-cut to have the existing photography of Peenemünde checked again, and requested additional cover as a matter of urgency. Photographs taken on 19 January 1943 were inconclusive, with snow covering much of the area, but another on 1 March showed interesting developments around the three circular revetments at the north-western tip of the Usedom peninsula, including the recent construction of several buildings similar to those being built in the coastal regions of France, the most likely area for launching missiles against London. This prompted the every persistent Pryor to call for new photo coverage of these areas, looking specifically for some sort of launching ramps, but nothing definite was found, and Medmenham concluded that, while there was no positive evidence that rockets and/or flying bombs were going to be launched from there, neither was there any evidence that they would not be!
There seems to have been some uncertainty within RAF circles as to the part they should be playing in this saga; assuming that the rocket was merely an extension to Germany’s long-range artillery, it was surely of more interest to the army and airmen should, therefore, limit their involvement to a ‘watching brief ’. As for the Americans, the archives show that information on Peenemünde was passed to a senior US official, Allen Dulles, in May, but it may be that they were not given the full picture on the possible threat to England and to the huge Allied invasion fleet mustering around the Channel ports, despite the contribution which the USAAF’s 8th and 9th Air Forces could make against the missile development, production and launch sites. Such an early opportunity to do so arose that month, when agents and PR revealed what could only be a launch site for V2s at Watten, in the Pas-de-Calais.
In April 1943 Bletchley Park had reported signals indicating that 14 and 15 Companies of the Luftnachrichten-Regiment (a German Experimental Air Signals Regiment) had deployed Würzburg G tracking radars to Rügen Island, Bornholm and several other locations along the Baltic coast to the east, which had been pinpointed, and which, together with reports from agents operating in the area, suggested forthcoming trials with ‘pilotless aircraft’. The first real ‘coup’ came on 22 April 1943 when the crew of a PR Mosquito, returning from a bomb damage assessment (BDA) sortie over Stettin, left their vertical cameras running as they flew home along the Baltic coast and over Peenemünde. From the photographs, the PIs at the CIU spotted an unusual object, some 25 feet long, shrouded in steam, with flames issuing from one end – which was no longer there on photographs taken 4 seconds later, leading them to assume that there had been a rocket of sorts launched there. Usedom was now being photographed by Mosquitos twice a week, those prints on 12 June revealing a 35 feet high, ‘white-ish’ cylinder, some 5 feet in diameter, with three fins at the tail end, very similar to objects photographed on rail trucks accompanied by fuel tankers. Throughout that month intelligence from Peenemünde continued to come in thick and fast, typically from agents such as the ‘Famille Martin’ in Luxembourg, the Frenchman Leon Henri Roth, and foreign workers accommodated in the Usedom’s Trassenheide camp – all pointing to the development of large rockets, with assembly units, launch pits and towers. More evidence came from a disgruntled Luftwaffe weapons officer who reported seeing ‘winged missiles’ and associated catapults at Peenemünde, supporting the notion of flying bombs. Finally, on 23 June, a Mosquito from 540 Squadron photographed two V2s, leaving Flight Lieutenant Kenny at the CIU in no doubt about the rockets. Duncan Sandys thought likewise, and despite Lord Cherwel
l’s continued scepticism, he recommended the earliest heaviest possible bombing of Peenemünde.
On 29 June 1943 Churchill and the Cabinet agreed and plans were laid for a precision raid by all available aircraft from RAF Bomber Command, to take place on the night of 17/18 August, in Operation HYDRA (See Chapter Eight). Their decision was vindicated when, on 16 August, a comprehensive dossier on weapons development at Peenemünde was acquired by the French agent Léon Faye and flown to England in an RAF Lysander of the Special Operations Squadron.
Post-Operation HYDRA the War Office called for more details on the weapons, ideally from human sources on the ground, despite security at Peenemünde having been tightened, and from those survivors of HYDRA who were then transferred to a new weapons range in Poland. Some V2 development work continued at Peenemünde, but the next test flight did not take place until seven weeks later. The Germans attempted to deceive the Allies by faking bomb damage there with black and white lines painted to simulate charred beams and dummy craters, all suggesting that the raid was far more successful than it was, thereby hoping to deter further raids, but the well-rehearsed PIs at the CIU were not fooled. There was no hiding place.