Heligoland

by George Drower

  Irrespective of whether or not Britain was contemplating using Dune as a shallow-water site for a base surge test explosion, there is no doubt that on at least two occasions after the war chemical weapons tests were carried out on Heligoland. One type was white phosphorus, which was dropped at low level by RAF bombers. The evidence for this comes from Heligoland fishermen. One night rough seas in the Bight forced several Heligoland lobster boats to seek shelter in the harbour there – although the island was deserted and access to it forbidden. The fishermen heard the drone of approaching aircraft, and then several waves of bombers roared overhead at low level. As the first wave passed they heard a whistling sound as bombs fell through the air on to the already ruined Unterland. Then the pitch-black night sky was suddenly illuminated by numerous interlocking flashes of blinding light as the phosphorus bombs exploded, throwing off enormous heat and showers of cascading offshoots which fell all around the open, wooden lobster boats. Even now the surviving fishermen can readily recall their fear during that bombing trial. One, Karl Bloch, claims: ‘When the next wave of bombers came in they were flying so low, and the light was so intense, I could actually clearly see the face of the pilot of one of them as it approached and sped over.’ It seemed the Air Ministry was prepared to try out almost any type of weapon on the defenceless island.

  Another hitherto unknown incident recalled by some older islanders occurred in the late 1940s. They make the astonishing claim that Britain had planned to explode a 100-ton ammonium nitrate bomb on the island. This scheme came to light when the ship carrying the chemicals for that trial exploded in the English Channel. Even so, they believe, other chemicals were saved and did reach Heligoland. Far-fetched it might seem but in fact compelling written evidence does exist in the Public Record Office in Kew, verifying the truth of their account. The declassified document AVIA 6/18589, written in February 1949, shows in words, diagrams and photographs that a huge chemical apparatus was assembled and burnt off on the island by British technicians. Since the early 1930s, when it became known that ammonium nitrate exploded when rapidly heated, it had been used as a constituent of various explosives. It was often described as a ‘fertiliser bomb’, but it had rarely been exploded on a large scale by itself. This February 1949 Royal Aircraft Establishment report, Analysis of Gas Samples from the Heligoland Nitrate Trials of Ammonium Nitrate, shows that a working party had been sent to the island to use specially constructed instruments to obtain gas samples of the atmosphere around fires burning in a bunker.

  In April 1947 the fortifications and U-boat shelters had been destroyed and thus the Potsdam terms fulfilled. This then was surely the time for Britain to stop all its military activity on Heligoland. Yet in some respects its involvement with the island was increasing. A memo in the secret Foreign Office file FO 371 (German General Economic), dated 1 December 1947, reported that: ‘The Explosive Storage and Transport Committee’s series of explosives trials [author’s emphasis] on Heligoland and Dune has now been completed and all naval and military personnel and equipment were evacuated to Cuxhaven on 27 November 1947. The islands are required by the Air Ministry for bombing practice from 1 December 1947.’

  The public were never informed that the RAF’s 10-ton Grand Slam bombs only achieved spectacular successes against a few U-boat shelters; on others where the concrete was thicker – as at Heligoland, Farge and Bergen – they had virtually no effect. With a perceived need to urgently develop a better and ‘tropicalised’ version of this weapon against Japan, the war in Europe having been won, the Chiefs of Staff initially met on 3 June 1945 to consider an RAF proposal for using Heligoland as a live bombing range at which to improve it. Seemingly Heligoland’s U-boat pens were of interest because they were the first Germany built with the especially heavy roofs. For the Air Force the unfortunately named Sir Douglas Evill said use of the island as a bombing range was urgently required until the defeat of Japan. Discussing the matter again on 14 June the Chiefs were persuaded by Sir Charles Portal to accept their argument on the grounds that there were ‘increasing difficulties in retaining existing ranges, and of obtaining new ones’. Two days later the Prime Minister, Winston Churchill, informed the Air Ministry that he had no objection to the island being used as a live bombing range.

  Peace had already been declared in the Far East when Project ‘Harken’ went ahead. Poor visibility over the Bight prevented it commencing until 1 January 1946. Modified Lancasters of 15 Squadron flew from Suffolk to drop various types of 12,000lb Tallboys from various heights.12 In 1945 it involved American forces based in Britain: the 8th Army Air Force using B-17s. In March 1946 Project ‘Ruby’, their name for dropping experimental earthquake bombs on Heligoland, was joined by B-29 aircraft which had just arrived in the UK and were stationed at Mildenhall – the same base as 15 Squadron. Declassified photos now show that even if dropped from 20,000ft the earthquake bombs scarcely had any effect on the U-boat shelter. Nevertheless the Anglo-American trials continued until July 1946, and it was during the course of the last of them that Captain Skipworth’s reconnaissance team was nearly wiped out.

  On 9 August 1946, just a fortnight after the Heligoland trials ended, the Air Ministry sent Penney detailed specifications for Britain’s envisaged free-fall atomic bomb – which was to be called ‘Blue Danube’. Those design requirements were much influenced by the capacity of the Lincolns (modified Lancasters) which might need to convey the bombs until June 1953, when the V-bombers were expected to enter service. Thus Penney was told: ‘The bomb should not exceed 290 inches in height, 60 in diameter; its weight must not exceed 10,000lb; and it must be suitable for release between 20,000ft and 50,000ft, at 150–500 knots.’ In October 1947 it was added that, in order to produce an effective underwater explosion, the bomb would need to withstand the shock of impact with water.13

  Meanwhile, despite the bombing range being temporarily closed while Woosnam rigged Heligoland for the ‘Big Bang’, the development of the Tallboy bomb continued. By September 1946 15 Squadron had been switched to dropping trial versions of it on the U-boat assembly shelter at Farge, near Bremen. At the Shoeburyness experimental establishment ballistic trials were conducted on models of the fuselage; and static conventional explosions of the Tallboy were done on the mudflats there, near the AWRE’s Foulness range.14 Design and prototype production was now shifting away from Tallboy’s originators, Vickers-Armstrong, towards the Royal Aircraft Establishment (RAE) working on an agency basis for Penney’s team. This meant that even Barnes Wallis, the inventor of the Grand Slam, was largely sidelined, although his views were sought. His diaries – now open at Imperial College, London – reveal that on 19–21 July 1945 he visited bomb-damaged Cuxhaven, and might have gone to Heligoland; on 26 October 1945 he had a ‘Meeting at Thames House – official introduction to the [Secret Intelligence] Service’; on 30 October 1945 he attended a ‘Tallboy Panel (Experiments)’; and as late as 7 February 1952 he was corresponding with the RAE at Farnborough who had requested Tallboy and Grand Slam technical data from him.15

  Codenamed Project ‘Emulsion’, a 1,000lb streamlined bomb was the simple evolutionary link by which the Tallboy was recognisably developed into the casing for Britain’s atomic bomb. A secret report on ‘Emulsion’ acknowledged this as early as May 1948: ‘The bomb shape chosen was similar to Tallboy, which experience had shown to behave well ballistically from medium altitude and a 1,000lb size was used for convenience in trials. The first step in the stabilisation of bombs at transonic and supersonic speeds was made by choosing the Tallboy shape of body and fitting five different types of tail to it. It was found that a fine spin 1.4 x bomb diameter was adequate to stabilise this bomb at the speeds reached with release at 35,000 feet and 350 mph.’16

  Emulsion was initially tested in the United States at the USAF’s Aberdeen proving ground at Atomic City, Idaho. Then, in 1949, the trial drops were focused on at the Orfordness bombing range on the Suffolk coast. Orfordness – where Penney’s AWRE had established another of
their characteristic enclaves – was serviced by a secret RAE airfield nearby, called Martlesham Heath. Struggling along with a special flight of four fatigued bombers (two Lincolns and two Mosquitos), the RAE were required to complete the series of Emulsion drop tests for the AWRE. However, because of unserviceable aircraft and inclement weather, during the winter of 1949/50 they fell behind schedule. Martlesham’s declassified operations record book discloses that in May pressure was increased by the delivery of unarmed prototypes of the Blue Danube: ‘A new task has been added, and the particular stores have been received and dropping has commenced. For this purpose a specially modified Lincoln has been received.’17 The number of sorties flown leapt in May, and the next month reached 33. Indeed, by June 1950 Penney and his scientists at Fort Halstead had put together a mock-up of the as yet untested British atomic bomb, codenamed ‘Blue Danube’, for members of the HEROD Committee to inspect. Was it at this crucial time that Martlesham’s secret AWRE flight bombed Heligoland?

  Inexplicably it was then that a specialist metal recovery programme, from early 1950 to early 1951, was instigated for the island. Every fortnight teams of metal collectors were to land on Heligoland to gather strategically valuable scrap. Somewhat intriguingly its codename was Operation ‘Top Hat’ – the confidential name used on the mainland to identify key physicists working for the occupying Allies.18 To this day Heligoland fishermen who happened to witness the postwar test bombings insist that the heavy bombs dropped had mostly concrete centre sections. This is not surprising because the use of concrete would have enabled the HER scientists to experiment cheaply and easily with various shapes. The fin and tail were presumably made of distinctively shiny blue chrome molybdenum steel.

  In the postwar years the British government never publicly revealed just how vital Heligoland was considered to be by a small miscellaneous group of influential officials. On 2 February 1950 the Chiefs of Staff Committee sent a paper to the Cabinet’s Defence and Overseas Policy Committee, which at the time was considering the future of Heligoland. In no uncertain terms the Chiefs insisted: ‘We consider it possible that if bombing-range facilities of the type provided in Heligoland were withdrawn the USAF might reconsider the basing of bombers in this country in peacetime.’ Heligoland clearly represented a valuable card to play in the crucial game of keeping the United States involved in Europe. Only when NATO was formed in April 1949 was there a binding commitment from the United States to help defend Western Europe against a possible threat from the East.19

  The USAF’s Strategic Air Command deployment in Britain of B-29A Superfortresses, which had an A-bomb carrying capacity, began in July 1948 in response to the Berlin Crisis. Until bombing ranges for the B-29As were opened in Iceland and West Africa they mostly practised their nuclear targeting skills with conventional weapons against Heligoland, where in September 1948 they jointly participated in Exercise ‘Dagger’ with the RAF. To keep the strength of the SAC’s presence in Britain obscure, various USAF B-29A squadrons were rotated on three-month tours of duty; while the UK airfields from which they operated were made to seem to be still entirely RAF bases.

  This is evident from a paper issued by the Chiefs of Staff on 2 February 1950, which twice refers, very clearly, to the range having been used by both the RAF and the USAF since 1946, and later mentions its being ‘also in continual use by the USAF bombers based in this country’. Whether or not those American B-29A bombers were sometimes carrying practice atomic bombs is not clear. The island’s location and shape provided the USAF and the RAF with an invaluable training venue. As the Chiefs of Staff had stated to ministers on 2 February 1950:

  Map 8 Exercise ‘Bullseye’: five years after the Second World War, Heligoland was still being heavily pounded by the RAF. On 1–2 June 1950 it was test bombed by 88 Lancasters and Mosquitos in Exercise ‘Bullseye’. Pleas from the exiled islanders to be allowed to return to their homeland were rejected; and the British High Commissioner in Germany threatened demonstrators with imprisonment. (Public Record office)

  We would emphasise that the need for a live bombing range such as Heligoland is not confined to the mere dropping of bombs. The long sea crossing provides unique opportunities to simulate realistic operational conditions, not only for the two Bomber forces, but also for our Air Defence System, which obtains valuable training in the reporting and intercepting of large forces of aircraft approaching from the east. In addition these practice bombing raids enable the pre-flight activities, navigation, target marking and other techniques concerning the approach and method of attack to be fully tested and evaluated on each occasion.20

  In addition to bombing runs by a few isolated aircraft dropping experimental weapons, mass raids were carried out by bombers. Codenamed ‘Bullseye’, these began on 5 April 1946 with an attack by pathfinding Mosquitos and 44 Lancasters carrying 1,000lb bombs. The event was believed to have been the first RAF mass training exercise since the war ended. A similar ‘Bullseye’ bombing of Heligoland occurred on 2 June 1950.21 Although each of the 49 Lincolns involved was ordered to take vertical pictures of the bomb releases and impacts none of those photographs is now known to exist.

  The Prime Minister, Clement Attlee, had been warned in a top secret note sent by the Defence Research Policy Committee that ‘If the atomic bomb is to be effective and economically used, the accuracy with which it is dropped must be of the high order achieved in the last stages of the last war.’ New navigation devices would have to be developed, and presumably tested, to achieve maximum precision. ‘The effort on these allied problems of navigation and accurate bombing is wholly insufficient and we are falling behind our target dates.’ The need for precision bombing skills to be kept at the highest pitch by means of practice – both for conventional and atomic bombs – was affirmed at a special meeting of the secret HEROD Committee, held specifically to discuss crew training on 16 November 1951. According to the minutes of that meeting: ‘It was agreed that practice bombs were essential for the training of the Air and Group crews who would be responsible for the delivery of atomic bombs.’ Heligoland was uniquely placed in this regard, as was admitted in the Chief of Staff’s 2 February 1950 briefing paper: ‘Heligoland is the only suitable site within a reasonable distance of Great Britain; no British islands are suitable.’

  By March 1950, the RAF was starting to take delivery of seventy B-29A bombers loaned from America. Although, because of the restrictive McMahon Act, those B-29A Washingtons were prevented from being fitted with A-bomb racks, in all other respects they were identical to the SAC’s own Superfortresses. Each of the eight RAF squadrons which operated the B-29A Washingtons practised their precision bombing techniques at the Heligoland range, sometimes in joint exercises with the USAF. Seemingly for some time prior to the introduction of the Canberra bombers – and then the Valiants in 1955 – it was on such Washington flights that future V-bomber aircrews were trained.

  Whatever hopes Britain might have had of using Heligoland as a site for an atomic bomb test would have been finally dashed in the autumn of 1951 by a seemingly chance remark in an obscure telegram sent by the British Embassy in Washington to the Cabinet Office in London. The telegram concerned the United States’ huge inland nuclear weapons test site in Nevada, and stated that ‘One of the earliest Nevada explosions of only 1 kiloton had caused considerable window damage at 75 miles.’ This apparently freak accident doubtless had a profound effect on any thoughts Penney and his team might have had of carrying out an atomic test on Heligoland. The Nevada accident appears to have been caused by detonating the atomic bomb too close to the mountains, which had the effect of greatly exaggerating the blast and widening the area affected by an enormous distance. Penney, who was an expert in blast and seismological effects, must have been reminded of the huge explosion caused on Heligoland on 15 October 1944 when the Aphrodite bomber crashed in the Unterland, wrecking the Biological Institute there and demolishing 24,600 sq. yards of domestic property. In a report written on 29 November 1944, D.G.
Christopherson of the Armament Department of the Ministry of Home Security noted that the scale of the blast damage appeared to have been influenced by the shock waves bouncing off the cliff. This was neatly illustrated with a bull’s-eye target diagram.22 It seemed likely that if an atomic bomb were tested in the shallow water off Sandy Island, shock waves would bounce off the cliffs of Heligoland and cause structural damage to buildings at Cuxhaven, just 30 miles across the Bight at the mouth of the Elbe, and perhaps even affect other towns and villages along the German North Sea coast. This put an end to the possibility of Heligoland being used for an atomic bomb test.

  The obvious alternative was to use Eniwetok Range, the United States’ testing ground – from where inhabitants had recently been exiled – in the Marshall Islands. Unfortunately, the timing for seeking permission to use that could hardly have been worse. As early as November 1945 Attlee and President Truman had signed the Washington Agreement to allow full and effective cooperation in atomic bomb development. Under the terms of this Dr Penney was involved with America’s A-bomb tests at Bikini Atoll. But in August 1946 the United States Congress had passed the McMahon Act prohibiting the passing of classified atomic information to any foreign country – including Britain. Even so, at a working level some exchanges of data did continue to take place between America and Britain. Pressure on Dr Penney to get Britain’s atomic bomb completed was further increased in August 1949 when the Soviet Union carried out its first atomic bomb test. Then in January 1950 disaster struck. Klaus Fuchs, the Imperial College traitor and the only other senior British scientist at the Bikini Atoll tests (where he helped to plan blast experiments against decommissioned warships), was arrested at Harwell, accused of passing secret information about Britain’s atomic bomb programme to the Russians before 1949.