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Introduction

1. At the end of the war in Europe in May 1945, 156 U-Boats surrendered. Of these, 10 were allocated to each of the three Allies (UK, USA and USSR) later in the year, one was repaired and commissioned into the French Navy, four were repaired and commissioned into the Norwegian Navy, three were scrapped in the Norwegian ports in which they had surrendered, two were sunk by the US Navy in February 1946, and 116 were sunk by the Royal Navy in Operation Deadlight between November 1945 and February 1946.

2. Thus, after the end of WW2, a number of U-Boats saw some degree of service with the Royal Navy, which also had an early opportunity to inspect and conduct trials with several U-Boats in addition to the 10 which were to be allocated to the UK. This was because almost all the U-Boats which surrendered in May 1945 had been transferred to Lisahally in Northern Ireland and Loch Ryan in south west Scotland in May and June, including those which were to be subsequently sunk in Operation Deadlight.

3. The formal position was that the 1945 post-war Potsdam Agreement included the decision to allocate 10 U-Boats to each of the 3 Allies for technical assessment and experimental purposes. This then led to the creation of the Tripartite Naval Commission (TNC) which was charged with determining exactly which U-Boats would be allocated to each country, and representatives of the TNC visited the UK in August and September 1945 to inspect the surrendered U-Boats. As a result, they decided which U-Boats should be recommended for allocation to the UK. However, despite this, and whilst the Royal Navy had no intention of ever using any of the surrendered U-Boats operationally, it was decided not to await the results of the TNC’s deliberations but, instead, to initiate the various planned tests and trials without delay. This action was taken with the full acquiescence and co-operation of the US Navy, but without notifying the Russians.

4. The purpose of this paper is therefore to set out the details of all of the U-Boats used by the Royal Navy, both before and after the formal TNC allocations. It will also highlight the scale of the Royal Navy’s involvement with the other U-Boats which had surrendered and then been transferred to the UK for storage pending decisions about their disposal.

Royal Navy Policy

5. Other than the retention of 10 U-Boats by each of the Allies for technical assessment and experimental purposes, a primary objective of the British Government and the Royal Navy was the elimination of the Kriegsmarine’s U-Boat fleet. This had been agreed at the Potsdam Conference, with the British position being set out clearly and strongly by both the Prime Minister, Winston Churchill, and the Foreign Secretary, Ernest Bevin.

6. At the 3rd Plenary Meeting of Allied Leaders at Potsdam on 19 July 1945, Winston Churchill said that:

He considered that the U-Boats should be destroyed or sunk. However, some of the most modern U-Boats had devices of interest to all three Powers, and these should be shared. He therefore suggested that, as part of a final settlement, most of the U-Boats should be sunk, and the small balance required for research should be shared. The number kept by the three Powers should be a token; more in order to spread technical knowledge than to keep large numbers in existence.

7. Similarly, at the 11th Meeting of Foreign Ministers at Potsdam on 1 August 1945, Ernest Bevin reiterated British policy by saying that:

The question is how many submarines should be saved and how many should be destroyed and how should they be divided. The British and American delegations had agreed that thirty submarines should be saved and the rest destroyed. The main thing, therefore, is that submarines be saved for experimental purposes only.

8. The British and the Americans were nevertheless determined (behind the backs of the Russians) to facilitate the earliest possible study of the latest types of high-speed German U-Boats, especially the new 1600 ton ocean-going type XXIs and the 250 ton coastal type XXIIIs. The Royal Navy was interested in both types, whereas the US Navy was particularly keen to discover the secrets of the larger, long-range, type XXIs. Also, the Royal Navy was aware from prisoner of war (POW) reports that the hulls of a number of U-Boats were covered with rubber sheeting, and were keen to discover the reasons for this development. Additionally, both the Royal Navy and the US Navy wished to acquire early information about and examples of the newly developed high test peroxide-powered Type XVII U-Boats.

9. By the time the war in Europe ended, the Royal Navy’s First Sea Lord, Admiral of the Fleet Sir Andrew Cunningham, and the other members of the Combined (UK/US) Chiefs of Staff (CCS) had become very suspicious of the Russians, and one of the principles adopted by the CCS was that no advanced technology should be allowed to go to Russia. Indeed, the First Sea Lord took specific action to ensure that advanced U-Boat technology should remain firmly in British and American hands.

10. Almost the first example of the application of this principle occurred in mid-May 1945 when the majority of the U-Boats which had surrendered in Europe were transferred to Lisahally in Lough Foyle, near Londonderry in Northern Ireland, and to Loch Ryan, near Stranraer in south west Scotland. This action, which had been approved by the Prime Minister, Winston Churchill, without any prior notification to the Russians, was carefully orchestrated by the Admiralty, as exemplified in a message on 17 May 1945 from Admiral Cunningham to the US Navy’s Admiral Harold Stark, the Commander of US Naval Forces in Europe, which said:

I enclose … a copy of a signal which the British COS have sent to our JSM [Joint Service Mission] in Washington concerning the disposal of the German U-Boats in Norwegian ports.

The policy set out therein has the approval of the Prime Minister. If you are in agreement perhaps you would support it with Admiral King [The US Navy’s CNO]. You will realise the urgency as the sooner we get these 100 or so U-Boats under our control in ports in the British Isles before our Russian allies start to ask questions the better. Perhaps I should also point out that bringing them over here constitutes an infraction of the rules, but I think we can get away with that.

As a result, when these transfers were implemented in the later half of May and throughout June 1945, this gave the British and the Americans the unique private opportunity that they required for the early study of the latest types of German U-Boat.

11. The British attitude towards the Russians was further exemplified a little later in the year when the Admiralty, in its Directive dated 13 August 1945 to Vice Admiral Geoffrey Miles and Rear Admiral William Parry, the British Representatives on the Tripartite Naval Commission, made it very clear that the Russians were to be denied access to the Walterwerke in Kiel. This was the factory where Dr Helmut Walter was researching and developing a whole series of new and advanced technologies related to the use of gas turbines for military purposes. These included the use of such turbines in submarines in order to produce the power required to drive them at high submerged speeds, and both the British and American authorities were determined that such technology should not fall into Russian hands. Thus, the unequivocal Directive included the statements that:

In particular, the Russians are not in any circumstances to be allowed access to the research laboratory, establishments or equipment of the Walterwerke.

The disposal of the latest types of U-Boat, fitted with hydrogen peroxide propulsion units, presents a problem of special importance and some difficulty. The most valuable boats are U-1406 and U-1407, which are fitted with the unit type 18X, and are capable of being completed within a reasonably short time. In addition, there are four badly damaged boats fitted with a smaller unit, type 17, namely U-792, U-793, U-794 and U-795.

It is desired to exclude the Russians from acquiring any of these special types of U-Boat. The Russians are, however, almost certainly aware of the existence of one or both types, and have a right under the [Potsdam] Protocol to inspect the boats. The exercise of this right, if a request is made, should be permitted, but inspection should be confined to the boats themselves and restricted to the minimum. You should report immediately any enquiries made by the Russians concerning these types [of U-Boat], and pending further instructions your case should be:

1. to maintain that U-1406 and U-1407 are the only boats of this type available for disposal within [the] Protocol.
2. to insist in concert with your USA colleague, that U-1406 and U-1407 are to be allocated to the USA and UK respectively.

The refusal of any of the U-792 to U-795 class to the Russians may be a delicate matter, but has great importance, since the acquisition of one of these boats might lead the Russians to put forward a claim under … the Protocol to examine and take equipment in the Walterwerke establishments for the purpose of providing spares for the U-Boats to be delivered to them. Further consideration is being given to the question of the disposal of these special types of U-Boat and establishments in relation to the Russians. Meanwhile, you should, if possible, avoid discussing the subject with the Russians.

12. There can therefore be no doubt that the Americans and the British were determined to ensure that, wherever possible, the latest German submarine technology should be denied to the Russians at the same time that it was being exploited by the Royal Navy and US Navy. Whether or not this eventually worked out in practice is a matter of debate, since the Russians had captured a considerable number of unfinished type XXI U-Boats in the shipyards in Danzig, and because they had also gained access to the plans for, and a full-scale model of, the HTP-powered Type XXVI U-Boat which would have been a larger and longer-range version of the Type XVIIB U-Boat. Also, the design of the Russian Navy’s "Whiskey" Class submarines developed in the late 1940s was influenced by the design of the type XXI U-Boats which they had acquired at the end of the war.

Pre-TNC Actions

13. The location in the UK of all the U-Boats that had surrendered in the Eastern Atlantic area, both from sea and in ports, well before the TNC was constituted in mid-August 1945, well before the TNC inspection parties had visited the UK ports, particularly Loch Ryan and Lisahally, and well before the TNC had announced even their initial allocation lists in October 1945, meant that the Royal Navy was able to initiate inspections and trials of a number of the surrendered U-Boats before the Russians had any opportunity even to view them.

14. Loch Ryan had been the location of a temporary wartime military port between mid- 1943 and February 1944, when it was used mainly by merchant naval ships, including US Liberty ships. There had however been no previous Royal Naval facilities there, and when the U-Boats began to arrive in June 1945 they were all moored in the Loch in open water.

15. In contrast, Londonderry at the head of Lough Foyle had been an important Royal Navy port throughout the war, and had played a major part in the Battle of the Atlantic. The name of the shore establishment was HMS Ferret, and it included Beach Hill Camp at Lisahally which had been commissioned in 1942 as HMS Ferret III, being used as the base for anti-submarine training by the US Navy. The American base had been transferred to the Royal Navy in late 1944, but was then closed as surplus to requirements. However, in view of the need to accommodate the surrendered German U-Boats, the base was temporarily re-commissioned in May 1945 as HMS Ferret IV, with the first Captain (Submarines), Lisahally and his staff arriving on 9 and 10 May, just before the first eight U-Boats arrived on 14 May

16. The idea of the Royal Navy conducting such trials on any captured U-Boats, and therefore the reason for the British Government proposing at Potsdam that a number of U-Boats should be retained for technical assessment and experimental purposes, had first been considered in 1944, culminating in a letter from Admiral George Creasy, who was Admiral (Submarines), to the Secretary of the Admiralty (1992/SM.04070 dated 15 October 1944) titled "Types of German U-Boats Required for Post War Experiments and Tests." This revealed that the Royal Navy already possessed a great deal of intelligence about the various U-Boat types operated by and being developed for the Kriegsmarine, some of which had been gained from the early type VIIC U-Boat, U-570 (HMS Graph), which had been captured by the Royal Navy in 1941, and which was then used operationally in 1942 and 1943, and the Admiral’s letter stated that:

A close study of the characteristics of all German U-Boats construction will be of great value, and to this end it is proposed … that a certain number of each type shall be taken over by the Navy for this purpose.

From both an operational and experimental point of view the type XXI U-Boat is of the greatest importance, followed by the type XXIII.

Types and numbers required are as follows, in order of priority:

Type	Number	Purpose
XXI	2 minimum	2 in commission
XXIII	2	1 in commission, 1 to cannibalise
XIV	1	strip and examine
IXD2	1	strip and examine
XB	2	1 in commission, 1 to cannibalise
IXG	2	1 in commission, 1 to cannibalise
IXD	1	strip and examine
VIIC/42	2	1 in commission, 1 to cannibalise

Of the above, submarines in commission would be kept available for seagoing trials. Submarines cannibalised would primarily be required to provide spare parts for submarines in commission, but would also be available for stripping and detailed examination.

17. These proposals, which were of course made before the war had ended, before any U-Boats had surrendered, and before it had been decided that the Allies would retain only 10 U-Boats each, were modified by Admiral Creasy on 7 March 1945, when (in a Minute on Admiralty file A/S.W.1694/44) he added the HTP-powered U-Boats to the list, saying that:

Since that letter [dated 15 October 1944 - see para 14 above] was written, fresh information has been received of newer types of U-Boat than the type XXI and XXIII … (Types XVII and XXVI). Admiral (Submarines) considers that numbers of these and any other new types will be required to at least the same scale as for the type XXIII, ie. two, one to commission and one to cannibalise.

18. The result of this pre-planning meant that the British and American forces which were advancing into north-western Germany, and which included amongst their formations a special unit changed with capturing and preserving equipment and facilities identified by Naval Intelligence, were able to locate examples of the very latest high-tech U-Boats that were required by the Royal Navy (and the US Navy), and thus ensure their early availability for the planned testing arrangements.

19. Thus, shortly after the German surrender on 9 May 1945 and the subsequent transfer of most of the surrendered U-Boats to the UK, the Royal Navy’s plans were put into effect. The latter started with a meeting held at Northways, London, NW3 on 25 June 1945, chaired by Admiral Creasy, to discuss

Trials to be carried out in, and with, U-Boats. The minutes of the meeting record the following opening statement:

Rear Admiral Creasy emphasised that, in considering what trials could be carried out with the U-Boats, two things must be taken into consideration:

1. That the Admiralty was acting as caretaker on behalf of the United Nations and that, therefore, the greatest care would have to be taken during trials that no damage was caused to the U-Boats.
2. That owing to the manpower situation only a very limited number could be manned for trials……He had been able to earmark four complete British submarine crews to man U-Boats for trials, one type XXI, one type XXIII and two type VIICs (one rubber covered).

20. To illustrate the size of the Royal Navy’s involvement in and commitment to the U-Boat activities in Loch Ryan and Lisahally, the minutes of the meeting also recorded that:

At the moment [June 1945] there were between 400 and 500 [Royal Navy] officers and men employed in looking after and maintaining the U-Boats.

21. At about the same time, the Royal Navy agreed that two of the 12 type XXI U-Boats stored at Lisahally awaiting decisions about their ultimate fate should be handed over to the US Navy. No type XXI U-Boats had surrendered from sea in the USA, and the US Navy was very keen to gain access to the German technology as soon as possible, as evidenced by a message from Cominch to ComNavEu dated 7 June 1945 which included the statement that the US Navy:

Now require from Europe following U-Boats - two Type 21.

22. In anticipation of such transfers, US Navy submarine crews had been flown to the UK in May 1945 and then been given accommodation and full support by the Royal Navy at Lisahally. The US Navy team was under the command of Captain G A Sharp, Commander of the US Submarine Mission to Europe (SubMisEu), and they initially took over control of one type XXI U-Boat (U-2513), one type VIIC U-Boat (U-1305), and one type IXC (U-802). However, U-1305 was quickly returned, and two more type XXIs (U-2506 and U-3008) were taken over by the US Navy team. However, the two U-Boats selected for transfer (U-2513 and U-3008) needed a considerable amount of work to restore them to full serviceability before their Atlantic crossing. There was also a shortage of spares, and this necessitated the cannibalisation of other type XXIs at Lisahally. Indeed, an American seaman almost lost his life during this process, when a fire broke out on 1 July whilst he was removing an electrical switch from U-2506 for use in U-2513.

23. A message from ComNavEu to US NavTecMisEu dated 16 July stated that U-2513 and U-3008, both Type 21 U-Boats, [are] now [in] temporary United States custody at Londonderry. ETA United States 15 August. But there was then a short delay as the Potsdam discussions were still underway, and the number of U-Boats to be allocated to each of the Allies was still to be finally agreed. The Potsdam Conference finished on 2 August 1945, it had been agreed that 10 U-Boats were to be retained by each of the Allies, and U-2513 and U-3008 were then immediately and covertly transferred to the USA (without the knowledge of the Russians), departing - after local sea trials - from Lisahally on 6 August, having first handed back U-2506 and U-802 into Royal Navy custody.

24. A diversion from the normal routine at Lisahally occurred on 19 July 1945, when there was a Royal Visit by King George VI, Queen Elizabeth and Princess Elizabeth. HM the King had asked to see the surrendered U-Boats that were moored there, and these included U-2513 and U-3008. At the time, these were the only two U-Boats that were fully operational, as well as being freshly painted. Thus, during the visit, the King was invited to inspect an American Honour Guard. He also talked to the COs and crews, and viewed the two U-Boats, but did not go onboard.

25. Following his meeting on 25 June, Admiral (Submarines) wasted no time in making the preparatory arrangements for the proposed Royal Navy trials with the type VIIC, type XXI and type XXIII U-boats. However, whilst none of these U-Boats were formally commissioned into the Royal Navy, even though they had RN COs and crews, they were nevertheless, with one exception, allocated N-series Pennant Numbers. To this end the two type VIIC’s, the rubber-covered U-1105 (N.16) and the standard U-1107 (N.19), arrived with the 3rd Submarine Flotilla (HMS Forth) in Holy Loch from Lisahally on 29 June. Then the type XXI ,U-2502, and the type XXIII, U-2326 (N.35), joined them in Holy Loch on 6 July, where they were moored alongside the accommodation ship SS Al Rawdah which, according to Captain (S/m) 3rd Submarine Flotilla, provided very comfortable berthing and accommodation, and excellent curry luncheons.

26. Admiral (Submarines) then, in his letter 1038/SM.4021 dated 12 July 1945, formally proposed to the Admiralty that the Royal Navy should conduct First of Class trials on U- U-2502 and U-2326. It was expected that the trials with the type XXIII, U-2326, could start quite quickly, but the type XXI, U-2502, needed to be docked and inspected before its trials could commence. The Navy Board approved the proposed programme of trials, and notified Admiral (Submarines) accordingly in its letter MO 6993/45 dated 27 August 1945.

27. Time was limited, so it was agreed that the trials should take place in and around the south west of Scotland - hence the transfer to 3rd Submarine Flotilla in Holy Loch. Unfortunately, however, the trials on both the type XXI and the type XXIII U-Boats proved to be very disappointing.

28. The trials with the type XXIII, U-2326, showed that the U-Boat suffered from engine and schnorkel defects: it did not complete its first dive until late July, and the First of Class trial, which took place between 27 and 31 August, revealed that its speed was less than anticipated. Also, there was a lack of on-board accommodation, and it suffered from poor sea-keeping qualities. Thus, once this and other trials had been completed by the beginning of October, Admiral Creasy reduced U-2326 to care and maintenance status at Lisahally, where it arrived on 15 October, and where it remained - after being allocated to the UK by the TNC - until its transfer to the French Navy in February 1946.

29. The Royal Navy’s experience with the type XXI, U-2502, turned out to be even worse. The U-Boat suffered from a whole series of defects, which required it to be docked in the Cammell Laird Shipyard at Birkenhead for inspection and repair before the trials could begin. U-2502 arrived in Birkenhead on 22 July 45 prior to docking and inspection in the No 4 Graving Dock, which was scheduled to occur from 24 to 29 July but, on 23 July its starboard main motor’s insulation caught fire and the starboard auxiliary motor suffered from overheating. The result was that U-2502 would have needed 4 to 6 weeks in the dock to repair the defects, as well as it being a complicated and expensive process which would have involved cutting out a section of the hull. The proposed trials with U-2502 were therefore cancelled on 28 July 45, and the U-Boat was returned to the moorings at Lisahally on 2 August for storage before eventually being scuttled in Operation Deadlight. U-3017 (N.41) was selected for the type XXI First of Class trial instead.

30. Unfortunately U-3017 was in only little better state than U-2502 and, after leaving Lisahally on 8 August 1945 for docking and inspection in the Vickers Shipyard at Barrow, there was a battery explosion during the initial hydrogen content trials on 29 August. This incident injured eight members of the crew and caused considerable damage, including severe fuel leaks and numerous other defects, all of which combined to put it out of commission, as well as causing Admiral Creasy, in his report to the Admiralty, No.1311/SM.3530 dated 7 September 1945, to say that:

It is therefore submitted for very early consideration that all trials with the type XXI U-Boats be cancelled.

31. In the same report, despite the fact that the UK was about to be allocated 10 U-Boats by the TNC for technical assessment and experimental purposes, the Admiral also clarified the Royal Navy’s longer term interest in the U-Boats, saying that:

If the above proposals [to complete outstanding trials on U-2326 and then pay it off, and to cancel all trials with the type XXI U-Boats] are approved, Admiral (Submarines) will only require five U-Boats for trials, viz:

Type XVIIB	Type VIIC	Type XXIII
U-1407	U-1105 U-1171	U-2326 1 spare

32. It also caused Admiral Creasy’s staff to advise, in their letter SM.3525/480 dated 8 September 1945, that:

Trials with type XXI [U-Boats] have been indefinitely postponed and may be abandoned.

33. Following the subsequent Royal Navy Board of Inquiry (BoI) into the battery explosion on U-3017, and what he considered to be fundamental design faults, Admiral Creasy - in his letter 1415/SM.3577 dated 4 October 1945 - stated that:

It is now apparent that, before U-3017 or any other type XXI U-Boat could be considered suitable for trials of a prolonged nature such as First of Type trials, a complete and extensive refit and survey would be necessary. This is not so in the case of U-2326, the type XXIII U-Boat which has completed First of Class trials, preceded by hydrogen content trials, nor in the case of the two type VIIC U-Boats [U-1105 and U-1171] now nearing completion of their trials. The necessity for this refit would, I consider, have been apparent early on in the proposed First of Class trials, even if the battery explosion had not taken place, in view of the number of defects which kept arising.

34. Although it then took some time for the Admiralty formally to approve Admiral Creasy’s proposals as set out in his report of 7 September and his comments on the BoI dated 4 October, U-3017 arrived back at Lisahally on 21 October, and a note on the Minute Sheet of Admiralty File M.06993/45 dated 2 November 1945 by the Director of the Operations Division (D.O.D.) records that:

Trials with type XXI U-Boats were cancelled by [the] Admiralty’s [message on] 141153/Oct.

35. Admiral Creasy therefore suspended the type XXI trials, especially as it seemed questionable whether these U-Boats would be any faster than the Royal Navy’s existing modified "S" class submarines. The problem was exacerbated by the fact that the capacity of British shipyards to refit any type XXI U-Boats was limited, and that there was a higher priority requirement to work on British submarines which needed to be refitted urgently.

36. The Minute Sheet note by D.O.D. on 2 November 1945 also records that:

U-3017 and U-2518 (Type XXI’s of the British allocation) are receiving Care and Maintenance, but both would require a large refit before any trials could be carried out.

37. Subsequently, when U-3017’s BoI findings were being circulated within the Admiralty, there is a joint file note from the Director of Naval Construction (29 Oct 45) and the Director of Electrical Engineering (2 Nov 45), which says:

German practice regarding battery ventilation in submarines has always involved a much lower factor of safety than in British designs.

The results [of the BoI] have shown the arrangements in type XXIs would require overhaul and modifications before they could be considered satisfactory.

Trials of ex-German submarines have been suspended, and no further action is considered necessary except to communicate the findings [of the BoI] to Allied authorities concerned.

38. This is followed by a handwritten note on the Minute Sheet of the same file dated 20 November 1945 which says:

The Americans are at Lisahally and presumably know all that is necessary already. It is surely asking for trouble to tell the Russians anything at all. Submitted take NFA [re telling the Allied authorities].

A proposal that was agreed.

39. On the other hand, it was clear that the US Navy was still intending to refit and then carry out trials on at least one of the two type XXI U-Boats (U-2513 and U-3008) that had been covertly transferred to the USA in August, and it was therefore decided that the RN would rely on the US Navy’s experience concerning their performance. Thus, the Admiralty accepted Admiral Creasy’s recommendation that there should be no further trials with any type XXI U-Boats. Also, by that time, the TNC had made its initial decisions and, out of the 10 remaining type XXI U-Boats at Lisahally, U-2518 (rather than U-2502) and U-3017 had been allocated to the UK.

40. U-2518 and U-3017 therefore remained moored at Lisahally on a care and maintenance basis, and it was acknowledged that they would both require a substantial amount of work before they could ever be made ready for any future trials. There was however little prospect that this would ever occur and, in February 1946, U-2518 was transferred to the French Navy. As a result, the Royal Navy had no further use for U-3017, even as a source of spares.

41. As far as U-2502 was concerned, it had been returned to the moorings at Lisahally in a very poor condition after its breakdown to await the TNC decision about its future, and (somewhat surprisingly) in mid-October it was initially allocated to the Russian Navy, despite its numerous defects and the fact that it had been cannibalized for spares. However, this quickly became apparent to the Russians and, on 1 November 1945, the Russian member of the TNC requested that it be exchanged for U-3041 (another of the type XXI U-Boats at Lisahally), a request that was readily agreed by the British member of the TNC on behalf of HMG on 14 November 1945.

42. One of the consequences of the UK decision to abandon trials with any of the type XXI U-Boats, and the US decision neither to transfer any type XXIIIs to the USA nor even to bid for a TNC allocation of any of these small, coastal U-Boats, was an informal agreement between the US Navy and the Royal Navy to exchange copies of any trials reports. However, whilst the UK trials report on the type XXIII U-Boat (U-2326) was provided to the US naval authorities in London in late 1945, the reciprocal arrangement in respect of the type XXIs was not so easily achieved, because the US Navy needed to refit U-2513 before any trials could begin in February 1946, and because U-3008 did not even become available to the US Navy until August 1946. Indeed, even the US Navy’s formal type XXI U-Boat Design Study Report did not become available from the Portsmouth Navy Yard until July 1946.

43. In respect of the type VIIC U-Boat, U-1105, there had been a certain amount of competition between the Allies, each of which wanted it for testing. This was because the U-Boat’s hull was covered with rubber sheeting. The Admiralty had known about this development since 1944 from Prisoner of War interrogation reports, but it was unsure as to its purpose, although it was thought that it was to help avoid detection by either radar or sonar. Thus there was very considerable interest in U-1105, which was eventually allocated to the USA by the TNC, after it had surrendered from sea on 10 May in Loch Eriboll, and then been moved to Lisahally. Both the Royal Navy and the Royal Air Force (Coastal Command) were very keen to check the implications of the rubber coating, and so U-1105 was included in the Royal Navy’s early (covert) testing programme, together with the standard type VIIC U-Boat U-1171. Indeed, the programme for the initial tests of these two type VIICs was discussed at Admiral Creasy’s meeting on 25 June, and they were started shortly thereafter.

44. There was a second rubber-covered type VIIC U-Boat amongst those which had surrendered. This was U-485, which had surrendered from sea in Gibraltar before being transferred to Loch Ryan. However, its coating was in a very poor state after almost 7 weeks at sea before surrendering, and when it was inspected by the TNC in September 1945 it was estimated that 3 to 6 months work would be required to make it operational. Thus none of the Allies, not even the Russians, were keen to bid for U-485’s allocation to them. Despite this, one of the Russian officers in the TNC inspection party at Loch Ryan attempted to remove samples of the rubber coating on the hull and the anti-radar composite on the schnorkel head, and had to be ordered to return them before the party left for the remainder of their UK inspection tour.

45. There was nothing particularly special about U-1171, other than the fact that it was one of the newer of the type VIIC U-Boats in British hands and, though it had been commissioned in March 1944, it had been used only for training rather than operational purposes. However, a standard type VIIC was required to take part in the important comparison tests with U-1105 before the latter departed for the USA to which it was to be allocated.

46. The trials with the two type VIIC U-Boats were conducted in several phases, one before the TNC visited the UK to inspect the U-Boats, and the others after the TNC had departed. The first phase had been agreed at the meeting at Northways on 25 June and was conducted in the sea area to the south west and west of Scotland, with the two U-Boats operating out of Holy Loch. After that, trials were carried out with Coastal Command at Tobermory and Londonderry, before returning to Holy Loch on 18 and 19 August for further trials. Thereafter both U-Boats were re-allocated to the 5th Submarine Flotilla (HMS Dolphin) on 2 October, and moved to Fort Blockhouse at Gosport prior to a further set of tests. These too were conducted off western Scotland, with the U-Boats being based at Rothesay on the Island of Bute.

47. After all the noise and detection tests were complete, and after spending Christmas 1945 in Holy Loch, U-1171 was finally returned to Lisahally on 3 February 1946 for de-commissioning and storage pending its final disposal, whilst U-1105 returned to the Royal Navy Submarine Base at Gosport, where it was handed over to a US Navy crew in early December 1945. After engine trials in the Solent, it finally left Gosport on 19 December and arrived at the US Navy Yard in Portsmouth, New Hampshire, on 2 January 1946.

48. Thus, as a result of almost all the surrendered German U-Boats being held in UK waters, by the time that the TNC made their initial allocations in October 1945, there had been considerable Royal Navy activity with a number of them. The type VIIC’s, U-1105 and U-1171, had been tested for noise and detection characteristics, and the small, coastal type XXIII, U-2326, had been tested in a formal set of First of Class and other trials, albeit that the tests had shown that its performance was less than expected.

49. Additionally, two of the large, ocean-going, type XXI U-Boats (U-2513 and U-3008) had been covertly transferred to the USA, the type XXI, U-2506, had been cannibalised for spares by the US Navy whilst moored at Lisahally, during which it had suffered from fire damage, the type XXI, U-2502, which had been scheduled for First of Class trials had suffered a major mechanical breakdown, and the type XXI, U-3017, which had replaced U-2502 in the trials programme, had suffered a battery explosion which caused all further RN testing of the type XXI U-Boats to be halted.

50. There were also several other U-Boats with which Royal Navy crews were involved between May and October 1945, albeit that they were all eventually scuttled in Operation Deadlight. The first two were U-776 (N.65) and U-1023 (N.83), each of which had surrendered from sea in Portland in May. Rather than being transferred quickly and directly to Loch Ryan and Lisahally, they were instead - crewed by a mixture of RN and German sailors - sent on long public exhibition tours of UK ports in order to raise funds for the King George’s Fund for Sailors.

51. U-776 left Portland on 21 May for a 10-day visit to London, and then visited numerous ports in the south east and east of the UK during a tour that lasted 60 days, and which included Southampton on the south coast and Lerwick in the Shetland Islands before arriving in Loch Ryan to await its final disposal.

52. Similarly, a Royal Navy crew took U-1023 on an 80-day tour of ports in the south west and west of the UK, starting at Portland on 25 May, and ending in Lisahally on 14 August. This tour included Plymouth, Bristol, Cardiff, the Liverpool area, Belfast, Glasgow, and the Isle of Mull on the west coast of Scotland. Thousands of people viewed the two U-Boats during their tours, and a considerable amount of money was raised for the King George VI Sailors Fund.

53. The third such U-Boat was the type IXC/40, U-532, which had surrendered from sea at Loch Eriboll on 13 May at the end of its return trip from the Far East, and which was then taken via Loch Alsh to Liverpool on 17 May for its cargo to be unloaded in the Gladstone Dock rather than being moved directly to Loch Ryan. However, this did not prove possible, and so U-532 was sailed to Barrow-in-Furness on 25 May for completion of the unloading process. Whilst in Liverpool, the U-Boat was inspected by Admiral Sir Max Horton amid considerable publicity - thus giving rise to the oft-repeated, but erroneous, story that it had surrendered there. The transit to Barrow, with a destroyer escort, was made with a mixed German and Royal Navy crew, and the unloading took place in a dry dock in the Vickers Shipyard. Whilst there, U-532 was opened to the public on 2 and 3 June, when some 7,500 local people paid a token admission fee for the opportunity visit the U-Boat before it was then sailed to Loch Ryan.

54. There were also three long range ocean-going supply/transport U-Boats which were carrying cargo either from or destined for Japan, and which needed to be unloaded. The first of these was the type IXD2, U-861, which had surrendered in Trondheim, Norway on 9 May having just returned from the Far East with war materials urgently needed by Germany. It was then moved to Lisahally, arriving there on 2 June. However, it was clear that U-861 was still carrying its cargo, which included a consignment of tin in its keel. Thus, on 10 June U-861 was transferred to Milford Haven by a mainly British crew, but also with some 20 Germans on board, where it was put into dry dock at Pembroke Dock. About 100 tons of tin and 30 tons of wolfram was removed from its keel, and about 40 tons of rubber was removed from the main ballast tanks before it was returned to Lisahally, but not before it had been open to the public from 15 to 20 June.

55. The others were two more type IXD2 U-Boats, U-874 and U-875, which were being used to transport essential war materials from Germany to Japan. U-874 had surrendered in Horten, Norway on 9 May, and been moved to Lisahally where it arrived on 30 May, and U-875 had surrendered in Bergen, Norway on 9 May, and been moved to Lisahally where it arrived on 6 June. However, it was soon realised that both these U-Boats were carrying cargo in their keels, and they were therefore transferred to Birkenhead for this to be removed in a dry dock. U-875 was the first to move, leaving Lisahally on 25 August with a joint Royal Navy and German crew, and then spending three weeks in dock at the Grayson, Rollo and Clover (GR&C) shipyard, where its cargo of optical lenses, mercury and iron were unloaded before it returned to Lisahally on 12 September. It was followed by U-874 on 19 September, again with a mixed Royal Navy and German crew, which was also docked in the CR&C shipyard, and from which optical lenses, mercury and zinc were unloaded. U-874 then returned to Lisahally on 22 October.

56. Whilst the start of the Royal Navy’s formal U-Boat trials programme had been initiated at the meeting at Northways on 25 June, there had been one earlier trial with the type VIIC U-Boat, U-249, which had surrendered at Portland on 10 May 1945. Whilst the other two U-boats which had surrendered at Portland had departed on their publicity tours of the East and West Coast ports in the latter half of May, the Admiralty instructed Flag Officer Portland on 18 May to retain U-249 in order to carry out special GSR (German Search Receiver) trials in conjunction with the Admiralty Signals Establishment. As a result, U-249 (which was allocated RN Pennant Number N.86) remained at Portland until 3 June, before sailing for Loch Ryan.

The Final TNC Allocation to the UK

57. The initial allocations of 10 U-Boats to each of the three Allies were agreed at the 13th meeting of the TNC on 10 October 1945, and the UK list comprised U-712, U-953, U-975, U-1108, U-1171, U-1407, U-2326, U-2348, U-2518 and U-3017. However, there was a last-minute change in late January 1946 when, as a result of a UK request, U-190 (which was located in Canada) was allocated to the UK, and U-975 (which had initially been allocated to the UK) was then added to the list of the unallocated U-Boats which were to be sunk in Operation Deadlight.

58. The final list of the 10 U-Boats allocated to the UK was therefore:

U-190, U-712, U-953, U-1108, U-1171, U-1407, U-2326, U-2348, U-2518 and U-3017

59. Eight of these U-Boats were moored at Lisahally, one (U-190) was in Canada at Halifax, Nova Scotia, and the remaining one (U-1407) was in the Vickers Shipyard at Barrow in the UK, details of their surrenders being as follows:

U-190	Surrendered from sea on 14 May in Bay Bulls, Newfoundland, Canada.
U-712	Surrendered on 9 May in Kristiansand(S), Norway. Transferred to Loch Ryan on 31 May. Moved to Lisahally on 30 December.
U-953	Surrendered on 9 May in Trondheim, Norway. Transferred to Loch Ryan on 29 May. Moved to Lisahally on 30 December.
U-1108	Surrendered on 9 May in Horten, Norway. Transferred to Lisahally on 27 May.
U-1171	Surrendered on 9 May in Stavanger, Norway. Transferred to Lisahally on 27 May.
U-1407	Surrendered in Cuxhaven, Germany on 5 May, but then scuttled on 7 May. It was raised on 1 July and towed via the Kiel Canal to the Howaldt-Werke shipyard in Kiel. At the end of August it was towed to Sheerness by the ex-Kriegsmarine tug Fohn 2, and from there it was towed to the Vickers Shipyard in Barrow-in-Furness by a British ocean-going tug.
U-2326	Surrendered from sea in Dundee, UK on 14 May. Moved to Loch Eriboll, arriving on 18 May. Transferred to Lisahally by 23 May.
U-2348	Surrendered on 9 May in Stavanger, Norway. Transferred to Loch Ryan on 27 May. Moved to Lisahally on 30 December.
U-2518	Surrendered on 9 May in Horten, Norway. Transferred to Lisahally on 3 June.
U-3017	Surrendered on 9 May in Horten, Norway. Transferred to Lisahally on 3 June.

Post-TNC Actions

60. After U-190 had surrendered from sea in Bay Bulls, Newfoundland, and then been moved to Halifax, Nova Scotia, it was commissioned into the Royal Canadian Navy (RCN). However, whilst the TNC had formally allocated U-190 to the UK as one of its 10 retained U-Boats, it was immediately handed-over to Canada by the UK, officially on a year’s loan, in recognition of the part played by the RCN in the Battle of the Atlantic.

61. In the course of the debates which led to the Potsdam Agreement, France had been keen to be allocated a share of the surrendered German fleet but, whilst the UK had considerable sympathy with the French request, it was vetoed by the USSR. Thus the French Navy was allocated no U-Boats by the TNC. Nevertheless, the UK decided that it did not need all the U-Boats that it had been allocated by the TNC, and so the Royal Navy agreed that one of its type XXIII U-Boats (U-2326) and one of its type XXI U-Boats (U-2518) could be transferred (on loan) to France.

62. The remaining seven U-boats which had been allocated to the UK by the TNC, which comprised four type VIICs (U-712, U-953, U-1108, U-1171), one Type XVIIB (U-1407), one type XXIII (U-2348) and one type XXI (U-3017), six of which - except for the Type XVIIB - had been in the UK since late-May and early-June 1945, and examples of each type had been subjected to numerous trials, the majority of which had been completed by the end of 1945.

63. This is confirmed in a file minute from Admiral (Submarines), reference SM.3517/994 dated 16 November 1945, which said:

All the technical requirements of Admiral (Submarines) for the U-Boats have been completed with the exception of U-1407… and a few weeks more trials with U-1171 (Type VIIC).

64. Thus, by early 1946, the status of the five U-Boats which Admiral (Submarines) had specifically stated in his report to the Admiralty on 7 September 1945 that he required for trials was as follows:

U-1407 had been commissioned into the Royal Navy with Pennant No: N.25.

U-1105 had been transferred to the USA for testing by the US Navy.

U-1171 had been returned to Lisahally on 3 February 1946 after RN trials.

U-2326 had been loaned to the French Navy.

U-2348 (the spare type XXIII) was moored (unused) at Lisahally.

65. So, other than U-1407, which had been allocated Pennant Number N.25 on 25 September 1945, the six U-Boats that remained in the UK (U-716, U-953, U-1108, U-1171, U-2348 and U-3017) were not required for any other trials, assessments or experimental purposes by the Royal Navy after U-1171 had returned to Lisahally on 3 February 1946.

The End of the Loch Ryan and Lisahally U-Boat Stories

66. In the case of Loch Ryan, after the sinking of 86 U-Boats in Operation Deadlight had been completed, the final three which remained (U-712, U-953 and U-2348) were transferred to Lisahally on 31 December 1945, and Loch Ryan’s role in the story of the U-Boats in the Royal Navy came to an end.

67. However, the same was not true of Lisahally. After the transfer of the 10 U-Boats to Russia, the sinking of the 30 U-Boats in Operation Deadlight, and the transfer of the two U-Boats to France, six U-Boats still remained at Lisahally at the end of February 1946, one of which (the type XXIII, U-2348) had experienced a battery explosion on 11 January, but fortunately without serious consequences or casualties. Of the six U-Boats, one (U-3017) had been earmarked for trials, but had been returned to Lisahally after an on-board explosion in August 1945, one (U-1171) had been used for trials between June 1945 and January 1946 before being returned to Lisahally, and the other four (U-712, U-953, U-1108 and U-2348) had neither even been used by the Royal Navy nor was there any further interest in using any of them for trial purposes. Indeed, in February, four of them had been hulked, and only two were being maintained in order to keep the remainder afloat. By then, the reason for which HMS Ferret IV had been set up in May 1945 and the purpose for which the Captain (Submarines), Lisahally had been established had ended, and HMS Ferret IV was paid off to care and maintenance on 19 July 1946.

68. In September 1946 the Admiralty announced that these six U-Boats had been allocated to the Ship Target Trials Committee for use as target ships. However, even then they remained unused and tied up to the jetties at Lisahally until 1947, when the Admiralty decided to re-commission the base as HMS Sea Eagle, which would be a school for anti-submarine warfare training (the Joint Anti-Submarine School - JASS). At the same time, the ex-Landing Ship-Tank (LST-3515), which had just been commissioned as HMS Stalker, was moved to Lisahally to act as the submarine support vessel for the Royal Navy submarines that were based there in support of the JASS. There was therefore a need to remove the six U-Boats from Lisahally, and so they were towed up the River Foyle for berthing at Londonderry.

69. However, despite this, no action was taken with these U-boats, and the Minutes of a Joint Meeting of the Ship Target Trials Sub-Committees held at the Admiralty in London on 1 July 1948 records that:

The Chairman of the [Joint] Committee explained that the main STTC would meet on 28 July 1948 to allocate targets, approve trial proposals, and arrange financial cover for 1949/50.

The Chairman of Sub-Committee 1 agreed that the 10 [British U Class] submarines remained a firm requirement for 1949/50, but [that it] had no proposals for the 6 ex-German U-Boats.

70. It is therefore clear that these six U-Boats were never used for ship target trials before being authorised for sale as scrap in early 1949. Thus the story of Lisahally and the surrendered German U-Boats in Lough Foyle, which had begun in May 1945, finally came to an end some four years after it had started.

Operation Pledge, Operation Deadlight, Operation Cabal and Operation Thankful

71. In the latter half of 1945 and early 1946 the Royal Navy also took the lead in four Operations which involved a major investment in time and effort, as well as considerable numbers of RN personnel and warships. These were the transfer of most of the surrendered U-Boats to the UK (Operation Pledge), the final disposal by sinking of the unallocated U-Boats stored at Loch Ryan and Lisahally (Operation Deadlight), the transfer from Lisahally to Libau of the 10 U-Boats allocated by the TNC to Russia (Operation Cabal), and the loan to France of the two U-Boats from the UK allocation, including their transfer from Lisahally to Cherbourg (Operation Thankful).

72. Operation Pledge, which took place between May and July 1945, concerned the transfer of the U-Boats which surrendered, either from sea in the western Atlantic or in ports in Germany and Norway, to Lisahally and Loch Ryan. It involved 137 U-Boats, 33 of which were moved via Loch Eriboll and Loch Alsh, 64 of which were moved via Scapa Flow, and 35 of which were moved from Norwegian, Danish and German ports via the sea route to the north of Scotland. The remaining five were transferred independently. In each case, whilst the U-Boats continued to be crewed by a number of German sailors, Royal Navy personnel, warships and facilities were involved, putting a considerable strain on the Navy’s resources at a time when the war in the Far East was still underway.

73. Operation Deadlight was the Royal Navy’s code name for the sinking of 116 U-Boats (86 from Loch Ryan and 30 from Lisahally) off Northern Ireland between 27 November 1945 and 12 February 1946. The Potsdam Agreement required the unallocated U-Boats to be sunk in deep water not later than 15 February 1946 and so, after the TNC had made its formal allocations in late October 1945, the Royal Navy decided that the disposal action should be initiated without delay. This was not only to meet the deadline of 15 February 1946, but also because the imminent onset of winter and its associated rough seas in the area to the north west of Loch Ryan and Lisahally would make the towing and scuttling of the U-Boats a hazardous task.

74. The formal order for Operation Deadlight was issued on 14 November, and the plan envisaged that all the U-Boats should be towed (unmanned) to a position 130 miles to the north west of Lisahally, which was 180 miles from Loch Ryan, where they would then be sunk. The prime method was to be by the use of demolition charges, however if weather conditions allowed, 36 were to be sunk by RAF and Fleet Air Arm aircraft, and others were to be sunk by torpedoes from RN submarines. If any of these methods of disposal failed, then the U-Boats were to be sunk by gunfire.

75. As expected, the weather was particularly bad in November and December 1945, and the planned disposal arrangements did not work on the majority of occasions, especially as far as sinking the U-Boats with demolition charges was concerned. There were major problems with towing the unmanned, unmaintained and, in many cases, almost unseaworthy U-Boats, and in the event only two of the U-Boats were sunk by demolition charges, only seven by torpedoes and only 13 by aircraft. Almost 50% foundered under tow before they ever reached the designated scuttling area. These either sank directly or were sunk by gunfire, some of them in positions very close to the entrances to Loch Ryan and Lisahally. The remainder were sunk by gunfire, as it was far too dangerous to follow the pre-planned demolition procedure.

76. The end of Operation Deadlight was marked by an interesting little story which is recorded in Captain (Submarines) Lisahally’s Monthly General Letter for February 1946 concerning the very last U-Boat to be sunk:

The type XXI (U-3514) lived up to the revolting reputation this class of submarine has achieved in ten months at Lisahally, by running aground when towed by three tugs, and had to be brought back to Lisahally. On the following day she was sailed again with the same three tugs and, after nearly seven hours of billiards, cannoning from mudbank to mudbank and side to side of the channel, she finally cleared Lough Foyle Buoy and Operation Deadlight was completed.

77. Operation Cabal was the Royal Navy’s codename for the delivery from Lisahally to the Russian-controlled Baltic port of Libau in Latvia of the 10 U-Boats that the TNC had allocated to Russia The original intention was that the 10 U-Boats should sail to Libau under their own power, with RN crews and one Russian naval officer on each as an observer. In the event, only five of the U-Boats were deemed to be capable of proceeding the whole way under their own power, and it was decided to tow the remaining five.

78. The transfer began on 24 November when nine of the U-Boats sailed from Lisahally. The five under power were escorted by HMS Garth, HMS Eglinton and HMS Zetland, and the other four were towed by HMS Riou, HMS Zephyr, HMS Tremadoc Bay and HMS Narborough. The tenth was a late substitute and did not sail until 6 December. The five U-Boats which sailed under their own power had a relatively trouble-free journey to Libau. However, it was a different matter for those that were under tow. The four which set out on 24 November experienced considerable bad weather on route, including Force 10 gales, and all had problems with their towing gear. Indeed, only seven of the U-Boats arrived at Libau on 4 December. The remaining three had all suffered considerable delays due to a combination of poor weather, technical defects and towing problems, with the last one (towed by HMS Icarus) not arriving until 2 February 1946.

79. Operation Thankful involved the transfer of U-2326 and U-2518 from the Royal Navy to the French Navy, and the move to France began on 5 February 1946 when HMS Tremadoc Bay sailed from Lisahally as escort for U-2326, together HM Tug Bustler which was towing U-2518. Both U-Boats were crewed by RN personnel. However, heavy weather in the Irish Sea, towing problems and defects caused a diversion into Dublin Bay on 7 February for three days. The transfer resumed on 10 February, with U- U-2326 now also under tow, and the group arrived in Cherbourg on 13 February where the two U-boats were handed over to the French Navy.

The Russian Connection

80. The Royal Navy played host to Russian naval officers on two occasions during 1945. The first was in August when the Russian delegation from the Tripartite Naval Commission (TNC) arrived in the UK to inspect the surrendered U-Boats at Lisahally and Loch Ryan prior to decisions about their ultimate fate. The second was in November when a party of Russians officers arrived at Lisahally to assist with the transfer of the 10 of the U-Boats to Libau in Operation Cabal. However, whilst personal relations between the naval officers of the three Allies in the TNC in Berlin were surprisingly cordial, the same cannot be said of the experiences in the UK.

81. The views of the First Sea Lord were well known amongst Royal Navy officers, and these were exemplified in the Admiralty’s Directive to the British Representatives on the TNC, which - in addition to its strong words concerning the Walter U-Boats - included such unequivocal statements as:

It is, generally speaking, HMG’s policy not to give the Russians technical or other information except on the basis of strict reciprocity, owing to the almost complete failure of the Russians heretofore to make information available to the UK.

You are accordingly to interpret narrowly the rights of inspection when applying it to the USSR.

In general, you should be aware that the Admiralty and other Departments of HMG have learnt by bitter experience that it is useless to negotiate with the Russians in a spirit of reasonable compromise.

82. It was therefore hardly surprising that the visits by Russian naval officers to Lisahally and Loch Ryan in August and September, as well as to Lisahally in November 1945 did not go as smoothly as might have been wished. It was clear before the TNC visits to Lisahally and Loch Ryan, which was scheduled to take place between 29 August and mid-September that, whereas the Russians wished to make a thorough and meticulous inspection of each U-Boat, the Royal Navy preferred a much shorter and quicker process. There were some 150 German naval vessels, including U-Boats, in the UK, and the RN wished to see the whole inspection exercise completed in 11 days, whereas the Russian proposals could take several months. In the end, the Lisahally and Loch Ryan inspections did not exceed their planned times, but there were some tense moments, particularly at Lisahally where the Captain (Submarines), Captain P Q Roberts, was not a man to be crossed. Indeed, after the inspection there were formal complaints by the Admiral who headed the Russian delegation to the TNC, including complaints about the hotel accommodation in London and Lisahally, the rudeness of certain Royal Navy officers, and the fact that radio and radar equipment had been removed from a number of the U-Boats. Needless to say, these complaints were given short shift by the Admirals in the British delegation to the TNC.

83. Similar problems arose in relation to the arrival in Lisahally of the Russian naval officers who were to accompany the 10 U-Boats to Libau. The Russians insisted on a meticulous examination of each U-Boat and demanded that all defects, however small, should be made good before sailing, even if this would require the U-boats to be docked. Again, however, these difficulties and delaying tactics, which included two requests for the transfer to be delayed, were given no credence by Captain Roberts, who also refused to delay the sailings. This resulted in a series of formal complaints from the Russian Naval Attaché in London, but again to no avail. The Royal Navy was not inclined to take instructions from the Russians.

84. Finally, there was a full-blown row between the Russian Naval Attaché in London and the Admiralty concerning the unexplained 6-week delay to U-3515 in Rosyth Dockyard between 14 December 1945 and 26 January 1946. U-3515, which was being towed to Libau by HMS Icarus had been diverted into Rosyth on 14 December because of problems caused mainly by bad weather. However, after that, and as described by the CO of HMS Icarus in his voyage report:

Icarus and U-3515 then remained in Rosyth Dockyard waiting for a serious defect in the submarine to be made good, and subsequently for the weather to moderate until Saturday the 26th January.

85. The exact nature and cause of U-3515’s defects is unclear, but on 20 December the starboard main (electric) motor was found to be damaged. The Russian Embassy in London believed that this might have been caused by sabotage, and on 24 December the Russian Naval Attaché wrote to the Admiralty saying that a spanner and iron filings had been found in the damaged motor. However, the carefully drafted reply from the Vice Chief of Naval Staff avoided answering the accusation and, instead, simply assured the Naval Attaché that HMS Icarus and U-3515 would sail for Libau as soon as weather conditions permitted. This may well have been a case of sabotage, but there was no way that the Royal Navy were going to admit it. It was nevertheless an illustration of the tensions that were affecting the relationship between the Royal Navy and the Russian Navy in the latter part of 1945.

The German Connection

86. There is no doubt that the U-Boat-related activities at Lisahally and Loch Ryan could not have been completed without the support and active participation of the German Navy POWs, most of whom co-operated actively, though there were some who were not so keen to assist. Almost all the U-Boats which arrived at Lisahally and Loch Ryan had some German crew members on board, both officers and other ranks, and to illustrate the size of the German POW contingent, the minutes of Admiral (Submarines)’s meeting on 25 June 1945 had included the statement that:

Rear Admiral Creasy emphasised that …at the moment [June 1945] there were between 400 and 500 [Royal Navy] officers and men employed in looking after and maintaining the U-Boats [in Loch Ryan and Lisahally], together with about 1,200 German personnel.

87. The prime task of the German POWs at Lisahally and Loch Ryan was the maintenance of the surrendered U-Boats pending decisions about their disposal or retention, and the Monthly General Letters written by Captain (Submarines), Lisahally between June 1945 and January 1946 illustrate the degree of involvement by the POWs:

1. June 45 Letter.

   So far the German maintenance crews have behaved reasonably well, though there are signs at times that they are getting somewhat restive, especially being cooped up in such a confined space.

2. July 45 Letter.

   The German crews continue to behave reasonably well although there have been one or two cases of German officers being unable to maintain proper discipline amongst their men. It is expected to move the German crews into camp accommodation early in August. While this should improve the cleanliness, it may react unfavourably on discipline when the ratings are accommodated together.

3. August 45 Letter.

   On the whole the Germans have given little trouble and continue to work moderately well, with the standard of cleanliness in the U-Boats slowly improving. The officers gave some trouble towards the end of the month, becoming obstreperous and threatening to go on strike; the removal of the blackest Nazi, firm action and a direct order to return to work proved effective. On 28 August the Camp accommodation ashore at last became ready for occupation and the German crews moved in during the day. In some respects their new quarters are considerably better than those occupied by British submarine crews in Lisahally Camp.

4. October 45 Letter.

   There has been no trouble at all with the German rating prisoners, but certain of the officers have given further trouble and five of them have been removed to a proper POW camp to undergo various sentences of detention. They had always been trouble-makers and they will not return here.

5. November 45 Letter.

   German prisoners have given no trouble and appear to be quite pleased at the forthcoming scuttling of their ships. The presence of numbers of Russian officers at Lisahally produced marked reaction.

6. January 46 Letter.

   Operation Deadlight was completed with few tears, even from the German prisoners, [and] the German prisoners are noticeably losing interest in their duties in the few U-Boats that are left.

88. After that, the final elements of the Royal Navy’s plans for the disposal and dispersal of the surrendered U-Boats held at Lisahally and Loch Ryan came to an end and, as recorded in the Lisahally Monthly General Letter for February 1946: On 13 February all German personnel were suddenly removed from Lisahally to their various prison camps. They were in fact transferred to the Army, which had the prime responsibility for their detention and eventual repatriation to Germany.

89. In contrast to the attitude that the Royal Navy adopted in relation to its German POWs, the US Navy SubMisEu took a slightly more relaxed approach. It was clear from the start that the US Navy would need assistance to ensure that their two type XXI U-boats were fit for their Atlantic crossing, and the Mission wished to include German crew members for the crossing itself. To help with the task of getting all the U-Boat systems’ working, the Intellegence staff at Lisahally therefore selected a group of non-Nazi prisoners who were willing to co-operate with the Americans. The group comprised four officers and about 25 petty officers, all of whom have served in Type VII or type IX U-Boats, although only a few had served any time in the type XXIs. However, as reported by the US Navy officer who would become the CO of U-2513 for its Atlantic crossing:

They proved useful to the point of being indispensable. A couple of the cleaner Type VII U-Boats were moved to our pier near U-2513 and U-3008 to serve as living quarters for them, and everyone, American and German, pitched in to get the two type XXIs ready for their trip to New London.

90. When the time to sail arrived, a number of the German POWs volunteered to help get the two U-Boats back to the United States and successfully operating thereafter. Thus one German officer and about 12 German petty officers were integrated into the crews of both U-2513 and U-3008.

U-1407 - HMS Meteorite

91. The Royal Navy’s acquisition of U-1407, which was an experimental Type XVIIB U-Boat with a (Walter) engine powered by high test peroxide (HTP), was the result of a carefully planned and orchestrated joint UK/US intelligence-led process which began well before the end of the war, and which involved the capture of the Walterwerke factory and its staff in Kiel on 5 May 1945, even before any of the formal surrender arrangements had taken effect in the city. Almost at the same time, the search began for the Type XVII U-boats themselves and, with the help of the Kriegsmarine’s Rear-Admiral Eberhard Godt who was the ex-Chief of Operations in the U-Boat High Command, U-1406 and U-1407 were located at Cuxhaven, where they had been scuttled by a German naval officer on 7 May, having first been surrendered by their COs on 5 May.

92. Such was the Allied (UK and US) interest in the Type XVII U-Boats that U-1406 and U-1407 were raised with great haste in Cuxhaven and moved to the shipyard in Kiel at the beginning of July 1945. However, whilst it was originally envisaged that they should be repaired and returned to an operational condition in a German shipyard, it was quickly realised that this would not be possible, and they were instead moved to the USA (U-1406) and the UK (U-1407) respectively for whatever further use was deemed appropriate.

93. In the case of U-1407, the Royal Navy was attracted by the possibility of HTP being an air-independent propulsion option. Thus, after arriving at the Vickers Yard in Barrow under tow and in a generally poor condition in August 1945, and then being allocated Pennant Number N.25 on 25 September 1945, before being formally commissioned as HMS Meteorite on 26 August 1947, it was eventually refitted with a new HTP turbine engine, which itself needed further repairs and development under the personal supervision of Professor Hellmuth Walter and a small team of German engineers who were taken secretly to Barrow to continue the work that they had started in Kiel.

94. Dr Walter himself had been briefly moved to London for interrogation in late-May 1945 before returning to Germany to continue with his work, and at the end of the year he and seven other engineers were transferred to Barrow where they were given contracts to continue their work on behalf of the British Government. Eventually, in 1946, the German party comprised 14 men, 13 wives and 24 children, thus emphasising the importance that the UK and the Royal Navy accorded to the research into HTP propulsion in submarines. This action was not however without controversy. On 19 December 1945, in a written reply to a question in the House of Commons, the President of the Board of Trade had to explain why German scientists and experts been brought to work in the UK. Also, there was considerable concern expressed in the local press in Barrow in early 1946 about the presence of the German engineers and the possibility that they were receiving better accommodation than that enjoyed (or suffered) by the local people.

95. The Admiralty’s intention was that the then U-1407 (N.25) was to be used purely experimentally and that, if the trials were successful, a decision would be taken as to its future use as a possible high-speed anti-submarine target for training purposes. The refitting of the submarine was however a particularly lengthy business which involved a complete overhaul, its re-equipment with new components brought from Germany, and a number of other major changes to the original U-Boat. They included the fitting of a new escape system, a complete change of the ventilation system, the replacement of all electrical equipment, and the removal of the torpedo tubes.

96. Thus the Royal Navy’s trials of the much-modified U-1407 (now HMS Meteorite) did not begin until 1948. The submarine left the dock at the Vickers Yard in Barrow at the end of January and, despite the lack of its HPT turbine plant at that stage, the Royal Navy decided to carry out preliminary First of Class trials off the west coast of Scotland, using just the diesel and electric motors for power. The main object of these trials was to familiarise the crew with the submarine’s general handling, and particularly to observe and understand its reaction to the controls, with a view to future high speed trials. These trials, which successfully tested both surface and submerged speeds, surface and submerged turning circles, and diving and change of depth performance, took place between 10 and 13 March 1948, after which HMS Meteorite returned to Barrow to have the HPT turbine plant fitted.

97. In the meantime, on-shore combustion trials had been taking place with the HTP turbine plant between July and September 1947. However, these revealed flaws in a number of components, and the final set of on-shore trials was not completed until July 1948, after which the HTP turbine was fitted to HMS Meteorite. Further surface trials then began, but these were not completed until October 1948 due to repeated postponements because of rough weather. The results of these surface trials were very promising. A speed of over 14 knots was obtained, and the Walter engine worked very well, despite rough handling. Indeed, a Royal Navy report written after the October surface trials, but before the full operational trials in March and April 1949, stated that:

Considerable confidence in the operation, as well a control and ease of handling the plant was gained. The only engineering troubles experienced were of a general nature, and were not directly connected with the turbine unit itself.

98. The same report reviewed the operational possibilities arising from the experience with HMS Meteorite, and the latter included the encouraging statement that:

The operational possibilities of a very fast moving submarine are obviously enormous. HTP is very expensive, but it is the only proven method in existence capable of propelling a submarine at high speeds for long periods. Any future HTP submarine would have a more powerful diesel engine and [electric] motor, and so some of the disadvantages of operating [HMS] Meteorite would not arise.

99. There were however a number of specific disadvantages, which included:

The expense of HTP, which costs at least £300 per ton and is in short supply.

The need for a fulltime escort vessel for accommodation.

The need for a storage ship for the HTP

The length of time taken to transit from harbour to any exercise area. On the surface, and in anything but the calmest of seas, the casing was almost continuously under water.

Meteorite’s grave lack of astern power. Hence, she is unable to stop quickly in an emergency should one arise.

None of the machinery was mounted on rubber, and the submarine was very noisy, thus facilitating detection by surface ships.

100. However, despite these disadvantages, the report concluded that:

It is realised that the disadvantage of expense of an HTP submarine is undoubtedly large. But while it remains the only proven method of very high speed propulsion, it is considered that the disadvantage is outweighed by the speed/time factor. This speed would probably be used mainly for escaping after an attack. With its help big changes of direction and depth could rapidly be made whilst at the same time, large distances are being covered, thus increasing by enormous proportions the difficulties of an escort vessel.

101. The main operational trials, both on the surface and submerged, with HMS Meteorite took place between 17 March and 30 April 1949, and are described in the report from the CO to Captain (S/m), Third Submarine Flotilla, reference No. H.32915 dated 1 June 1949.

102. The time between 17 and 24 March was taken up with the HTP fuelling process in the Barrow area, after which HMS Meteorite was towed from Barrow to Rothesay Bay on the west coast of Scotland. Then, between 27 March and 1 April, it carried out general handling trials and submarine drills, the results of which were recorded as:

Meteorite is an outstandingly difficult boat to handle on the surface.

She is outstandingly easy to handle dived.

She will not turn at all unless she has headway.

HMS Meteorite has extremely little stern power and will not steer at all going astern.

The turning circle on the surface is comparatively large.

Handling HMS Meteorite dived is as easy as handling her on the surface is difficult.

HMS Meteorite is undoubtedly slow at changing depth.

103. However, that said, the trials report concluded that all the machinery had been proved, and that the crew had gained experience and confidence in handling the boat dived. Thus, the initial phase of the trials was considered to have been successfully completed.

104. The next stage comprised a series of initial surface trials of the HTP turbine between 1 and 5 April in Loch Long, before HMS Meteorite was towed south to Loch Ryan for the main HTP-powered trials, both surface and submerged. The latter began on 6 April, and the report says that During this, and at all later high-speed trials, HMS Meteorite handled perfectly. After that, it was moved to the Campbeltown area, but though the first test runs on 7 April at a depth of 60 feet depth were successful, excessive vibration became evident at maximum power and speed, and it was shortly followed by a fire in the turbine room. The fire was easily put out, and was attributed to excessive oil in the turbine room bilges rather than any mechanical failure of the machinery itself.

105. Thus the submerged high-speed trials continued on 11 April and, once again, they were all completely successful, giving rise to the CO’s comment that:

It was also during these runs that the staggering manoeuvrability of HMS Meteorite at high speeds was discovered.

106. This led to two important conclusions:

It is considered that a small and fast submarine, even with the very high manoeuvrability of HMS Meteorite at 14 knots, would be a very hard target for an A/S ship to sink.

It would have been extremely interesting to have been able to observe the manoeuvrability of HMS Meteorite if she had been refitted with the two [HPT] turbines as designed, thereby giving her a designed speed of 25 knots.

107. After a short lay-up at Greenock, a final set of noise trials took place on 29 April, before HMS Meteorite was towed back to Barrow, reaching there on 30 April 1949. However, despite the changes to the submarine, as well as the optimism concerning its propulsion system and the successful high-speed trials, HMS Meteorite was not popular with the Royal Navy crews, who regarded it as a risky piece of machinery. Nevertheless, the trial results were sufficiently encouraging for the Admiralty to place an order for two larger British-built experimental HTP-powered submarines, with the original intention - which was not pursued because of the advent of nuclear propulsion - of eventually ordering an operational fleet of up to 12 such submarines.

108. Finally, in mid-1949, prior to its disposal as scrap later in that year, HMS Meteorite (U-1407) was taken out of service with the Royal Navy. Admiralty Acquaint SMBA Serial No.3512 dated 17 June 1949 (written just 17 days after the report on HMS Meteorite’s operational trials had been submitted) records that Approval has been given to the scrapping of HM Submarine Meteorite after the examination and removal of certain items of equipment, and Admiralty Acquaint SMBA Serial No.3530 dated 16 July 1949 records that HMS Meteorite was paid-off [decommissioned] on 8 July 1949.

The Final Disposal of the U-Boats Allocated to and Used by the Royal Navy

109. Whilst the focus of this paper has been on the 10 U-Boats that were allocated to the UK by the TNC, it should not be forgotten that the Royal Navy was also involved with five other U-Boats. First, there was the type XXI, U-2502, which was earmarked in July 1945 for the initial First of Class trials, but which in a very short time became too unserviceable to be of any use. It was therefore returned to its moorings at Lisahally to await its final disposal in Operation Deadlight. Second, there were the two type XXIs, U-2513 and U-3008, which were handed over to the US Navy at Lisahally in July and then covertly moved to the USA in August without the knowledge of the Russians. Third, there was the modified type VIIC, U-1105, and the standard type VIIC, U-1171, which were jointly subjected to a lengthy set of trials before the Royal Navy handed U-1105 over to the US Navy in December 1945 and returned U-1171 to Lisahally in February 1946.

110. Finally, the seven U-Boats which remained in British custody after U-190 had been transferred to Canada, and after U-2326 and U-2518 had been transferred to France, were handed over to the British Iron and Steel Corporation (BISCO) for breaking up as scrap.

111. The process for scrapping Royal Naval vessels at that time was that they would be handed over by the Admiralty to BISCO, which would then allocate the vessels to suitable ship-breakers, after which they would arrange to deliver the vessel to the ship-breaker, usually under tow. The ship-breaker was just a sub-contractor, and so - by definition - most surplus warships were not sold to any specific ship-breaker. Rather they were allocated the vessels by BISCO, which would make all the necessary disposal arrangements, and eventually reimburse the Admiralty.

112. Thus, in early 1949, as was formally recorded (albeit after the event) in the Admiralty’s “Acquaint”, SMBA No 3597 dated 15 December 1949, the six U-Boats moored at Londonderry/Lisahally, as well as U-1407/HMS Meteorite at Barrow, were handed over to BISCO and then transferred to various ship-breakers yards around the UK for disposal action later that year or in early 1950, as follows:

U-712	Arrived at the Thomas Ward ship-breaking yard at Hayle, Cornwall on 26 June 1949, and broken up during 1949/1950.
U-953	Towed from Londonderry on 30 May 1949 by the tug Guardsman. Arrived at the Clayton and Davie ship-breaking yard at Dunston-on-Tyne, Newcastle on 4 June 1949, and broken up during 1949/1950.
U-1108	AArrived at the Thomas Ward ship-breaking yard at Briton Ferry, Glamorgan, S Wales on 12 May 1949, and broken up during 1949.
U-1171	Towed from Londonderry on 9 June 1949 by the tug Guardsman. Arrived at the Thomas Young’s ship-breaking yard in Sunderland on 13 June 1949, and broken up during 1949/1950.
U-1407	Moved from the Vickers yard at Barrow to the Thomas Ward Ltd ship-breaking yard at Barrow on 7 September 1949, and broken up during 1949.
U-2348	Allocated for scrapping to the John Lee and Co ship-breaking yard at Belfast (Larne) in April 1949.
U-3017	Arrived at the J Cashmore and Co ship-breaking yard in Newport, S Wales on 25 October 1949, and broken up during 1949/1950.

Conclusion

113. Despite the determination of both the UK Government and the Royal Navy to see the total elimination of the remaining German U-Boats at the end of the war, there was great interest in viewing and learning from German U-Boat designs and technology, particularly where it was anticipated to be an advance on British submarine technology. Thus, the UK fully supported the retention of 10 U-Boats by each of the three Allies for technical assessment and experimental purposes.

114. The Royal Navy was particularly interested in the very latest high-speed U-Boat types, both coastal and ocean-going, and was therefore keen to acquire and test at least two of the large type XXIs and two of the small type XXIIIs. It was also keen to study one of the experimental Type XVIIB HTP-powered U-Boats, as well as a type VIIC which had an anti-sonar rubber coating over its hull.

115. Although the TNC’s allocations were not made until late 1945, the fact that most of the surrendered U-Boats were moored in the UK pending decisions about their final disposal meant that the Royal Navy’s U-Boat testing programme could be initiated in June 1945. As a result, most of the necessary trials, some of which took place on U-Boats which were not even allocated to the UK by the TNC, had been completed by the end of the year. The trials with the type XXI U-Boats (U-2502 and U-3017) had proved unsatisfactory and had been abandoned, but those with one of the type XXIII U-Boats (U-2326) had been completed, as had those with the two type VIIC U-Boats (U-1105 and U-1171).

116. The only U-Boat operated by the Royal Navy after January 1946 was the Type XVIIB, U-1407. This U-Boat was formally commissioned as HMS Meteorite in August 1947, but no sea-going trials took place until 1948 after the completion of a comprehensive two and a half year overhaul, refit and upgrade. Indeed, its full operational trials did not take place until March and April 1949 and, though these were generally successful, the submarine was decommissioned in July 1949 very shortly after the trials report had been submitted.

117. The Royal Navy was also very heavily involved in all the ultimate disposal of the German U-Boat fleet as a whole. This stemmed from the decision to move almost all the U-Boats that had surrendered in Western Europe to the UK for safe keeping prior to decisions about their final fates. Thus the Royal Navy played a major role in Operations Pledge, Deadlight, Cabal and Thankful, as well as having to supervise and maintain all the U-Boats throughout the second half of 1945.

118. Finally, of the 10 U-Boats that were allocated to the UK by the TNC, one was passed to Canada in 1945 (U-190), two were passed to France in 1946 (U-2326 and U-2518), and the remaining seven, including HMS Meteorite, (U-716, U-953, U-1108, U-1171, U-1407, U-2348 and U-3017) were sold for scrap in 1949.

119. The very last chapter in the story of the U-Boats in the Royal Navy post-May 1945 is therefore formally recorded (albeit after the event) in the Admiralty’s Special Military Branch Acquaint Serial No 3597 dated 15 December 1949, which said that:

The following ships have been handed over to the British Iron and Steel Corporation for breaking up: U-712, U-953, U-1108, U-1171, U-2348, U-3017 and [HMS] Meteorite.

Arundel, W Sussex July 2011