U-Boats that Surrendered - Operation Pledge

by Derek Waller


Operation Pledge filled the gap between the surrender of the U-Boats in Europe in May 1945 and their final disposal in either Operation Deadlight or their allocation to the three Allies (UK, USA and USSR). Thus it covered the transfer of the U-Boats which surrendered, either from sea or in port, to the Royal Naval anchorages in Lough Foyle in Northern Ireland and Loch Ryan in south west Scotland.

It has been given very little specific print space, and has generally been ignored by most of the publications which deal with this aspect of the post-war history of the U-Boats. It gets a passing mention on page 303 of Roskill’s "The War at Sea 1939-1945, Vol III, Part II" (1961), as well as on pages 13 and 57 of Madsen’s "The Royal Navy and German Naval Disarmament 1942-1947" (1998) but, other than those, there is a paucity of detailed information in any single document. This note therefore seeks to redress the balance.

German Naval Disarmament

With the objective of ensuring total German naval disarmament, the Royal Navy intended that, at the cessation of hostilities, all German U-Boats would immediately be removed to the UK prior to their destruction. Thus, in the first half of 1944, the Royal Navy began detailed planning for the post-war transfer of all surviving German U-Boats to British ports.

Initial Planning

In a message to the Admiralty (W.A. 2337/00770/122) on 5 August 1944, the RN’s C-in-C Western Approaches proposed that the 238 U-Boats, which was then the estimate of the number likely to surrender at the end of the war, should be moved to and stored at four UK naval anchorages. These were at Lisahally in Northern Ireland (70 U-Boats), Loch Ryan in south-west Scotland (100 U-Boats), and two anchorages in the Gare Loch in western Scotland - Roseneath (36 U-Boats) and Faslane (32 U-Boats). The figure of 238 was an intelligence-based assessment, and it was not envisaged at the time that in May 1945 over half of the remaining operational U-Boats would be scuttled by their crews rather than surrendered.

In response, the Admiralty in their message (M.057724/44) on 21 September 1944 gave their agreement to the C-in-C’s outline plans, but advised that any final decision would be delayed pending discussions about the number of RN personnel who would be required for the task, as well as wider issues relating to Allied agreement concerning the whole question of the disposal of the surviving U-Boats.

In the event, and as the end of the war approached, the number of U-Boats thought likely to surrender was much reduced, and thus the RN’s plans centered just on the port at Lisahally (HMS Ferret), near Londonderry, in Lough Foyle and the anchorage at Cairnryan in Loch Ryan.

Detailed Planning

On 19 March 1945 Admiral Sir Max Horton, the C-in-C Western Approaches, asked the Admiralty (in his message 191529A March) for clarification concerning the detailed procedures for the surrender of the U-Boats and their internment at Loch Ryan and Lisahally. As a result, a meeting was held at the Admiralty in London on 27 March to discuss the outstanding questions, because the C-in-C wished to issue early executive instructions for dealing with the surrendering U-Boats. The process was to be split into two stages. First, the surrender of U-Boats from sea (Operation Pledge One) and, second, the disposal of the U-Boats in German and German-controlled ports.

A number of important points were agreed at the Admiralty meeting, including that, for planning purposes, it was estimated that no more than 160 U-Boats might surrender in the British Zone (which included Germany, Denmark and Norway). Also, it was agreed that these would be held equally between Lisahally and Loch Ryan, where only minimal maintenance would be provided because the UK was continuing to seek Allied agreement for the wholesale scrapping or sinking of the remaining U-Boats as early as possible after hostilities ended. Additionally, in respect of any U-Boats in Norway and Denmark, the U-Boats would be moved as soon as possible after their surrender in order to protect the crews from local vengeance.

It was confirmed that, in respect of the U-Boats that surrendered in the British Zone, they would be sailed in groups to Loch Ryan or Lisahally, but only after first being put into a non-operational condition. It was proposed that the crews of the U-Boats moored in Loch Ryan should live afloat, but as the U-Boats at Lisahally would be lying alongside the jetty, the Germans would be accommodated in a nearby camp.

Following the 27 March meeting, detailed arrangements were made for the transfers, with Loch Eriboll being designated as a "Port for Preliminary Examination", Loch Alsh being designated as a "Port for Final Examination" and Lisahally and Loch Ryan being designated as "Ports for Laying-Up". Loch Eriboll, near Durness in north west Scotland, had been chosen because it was a remote anchorage where minimum damage could be done by a "rogue" U-Boat, and Loch Alsh, in western Scotland, had been selected because it was sheltered, because it could accommodate 33 U-Boats at buoys at any one time, and because it possessed a Naval Organisation and a railhead.

The Surrender Arrangements

On 4 May the German Navy had ordered all U-Boats to cease operations and return to Norwegian ports. Thereafter, the surrender of the Kriegsmarine took place in two phases.

First, there was the surrender of all German armed forces in Holland, Denmark and northwest Germany, including the Frisian Islands, Heligoland and all the islands in Schleswig Holstein to Montgomery’s 21st Army Group. This was signed on 4 May, and came into effect at 0800 hours (German Summer Time) on 5 May. It required all German forces to lay down their arms and to surrender unconditionally, and specifically included all naval ships in these areas.

Then there was the general German surrender signed at Reims on 7 May which came into effect from 0001 hours (German Summer Time) on 9 May. This led, on 8 May, to the issue of the specific pre-planned Admiralty order (under the codeword "Adieu") that all U-Boats, including those in Norwegian ports, were to surrender with effect from 0001 hours on 9 May, and that those at sea were to head for designated reception ports; the prime one of which was Loch Eriboll.

As a result of these instructions, 156 U-Boats surrendered to the Allies on both sides of the Atlantic.

Loch Eriboll

In order to implement Operation Pledge it was necessary to organise suitable reception arrangements in the naval anchorage at Loch Eriboll, which had no permanent RN port facilities. Thus, on 6 May the 21st Escort Group was ordered to proceed to the Loch to secure the anchorage and prepare for the surrender of a then unknown number of U-Boats. The 21st Escort Group and other naval units which comprised the Loch Eriboll Force arrived on 9 May.

The first U-Boat to surrender arrived on 10 May and, between then and 18 May, a further 17 U-Boats arrived in Loch Eriboll, as follows:

10 May - 4 (U-1009, U-1058, U-1105 and U-1305)

11 May - 4 (U-293, U-802, U-826 and U-1109)

12 May - 1 (U-956)

13 May - 3 (U-532, U-825 and U-1231)

14 May - 4 (U-244, U-516, U-764 and U-1010)

17 May - 1 (U-255)

18 May - 1 (U-2326 - which had previously surrendered in Dundee)

None of these U-Boats spent long at Loch Eriboll. Instead, with RN armed guards on board, they were moved quickly to Loch Alsh where the majority of the German crews were taken into captivity, and from there they were moved to Lisahally to await final disposal.

On 16 May the Norwegian Navy destroyer Stord had sighted a convoy of German naval vessels, including 15 U-Boats (U-278, U-294, U-295, U-312, U-313, U-318, U-363, U-427, U-481, U-668, U-716, U-968, U-992, U-997 and U-1165) which were being moved to Trondheim from Narvik where they had surrendered on 9 and 10 May. This Narvik group was then intercepted by the 9th Escort Group on 17 May and, instead of being allowed to continue to Trondheim, was directed to the UK as part of "Operation Pledge". Thus, after their interception, the 15 U-Boats were escorted across the North Sea to Loch Eriboll, arriving on 19 May.

By midnight on 21 May, all had sailed for Loch Alsh for onward movement to Lisahally, where the last of the 33 U-Boats that had either surrendered at or been processed at Loch Eriboll arrived on 23 May.

Scapa Flow

Once the 15 U-Boats from Norway had been processed it seemed likely that no more U-Boats would surrender from sea at Loch Eriboll. The Operation Pledge reception organisation was therefore moved from Loch Eriboll to Scapa Flow in the Orkney Islands on 28 May, where the ex-WW1 Battleship "HMS Iron Duke" was the RN base and depot ship, in order to process the remaining U-Boats that had surrendered in Norwegian ports and thus needed to be moved to either Lisahally or Loch Ryan.

The process was given added impetus because, as a consequence of the German Navy’s instruction on 4 May that all fully operational U-Boats in German and Danish ports and waters should if possible proceed to Norway, by mid-May the Norwegian ports were over-crowded with surrendered German naval vessels. It was therefore decided that there was an urgent need to clear the Norwegian ports, and on 24 May the Admiralty ordered that all serviceable U-Boats should be moved to the UK as soon as possible. This was supported by an instruction from Allied Naval HQ on 25 May that the sailing of these U-Boats was to be given the highest priority.

The first group of 12 surrendered U-Boats (comprising four from Horten (Oslo) - U-170, U-874, U-975 and U-1108, and eight from Stavanger - U-637, U-901, U-1171, U-2322, U-2324, U-2329, U-2345 and U-2348) arrived at Scapa Flow on 30 May and, after processing, were sent to Lisahally and Loch Ryan. Between then and 5 June, a further 52 U-Boats arrived from Norway at Scapa Flow from where they were transferred without delay to either Lisahally or Loch Ryan:

31 May - 24 (10 ex-Trondheim boats; U-483, U-773, U-775, U-861, U-953, U-978, U-994, U-1019, U-1064 and U-1203, 13 ex-Bergen boats; U-245, U-298, U-328, U-868, U-928, U-930, U-1002, U-1004, U-1022, U-1052, U-1061, U-1272 and UD-5, and 1 ex- Kristiansand (S) - U-281)

1 Jun - 13 (ex- Kristiansand (S) - U-299, U-369, U-712, U-1163, U-2321, U-2325, U-2335, U-2337, U-2350, U-2353, U-2354, U-2361 and U-2363)

2 Jun - 1 (ex-Stavanger - U-3035)

4 Jun - 13 (ex-Bergen - U-218, U-539, U-778, U-875, U-907, U-991, U-1004, U-1005, U-1057, U-1271, U-1301, U-1307 and U-2328)

5 Jun - 1 (ex-Kristiansand (S) - U-2334)

As with the U-Boats which had been processed in Loch Eriboll, the 64 which were processed at Scapa Flow only remained there for a short time, though in this case, as Scapa Flow was a fully constituted Royal Naval base, they did not need to transit via Loch Alsh to disembark German prisoners, but instead were moved directly to either Lisahally (14) or Loch Ryan (50). The last group of U-Boats left Scapa Flow on 6 June, and the Operation Pledge reception force at Scapa Flow was then formally disbanded.

The Remaining U-Boats

After 5 June there were still 35 seaworthy surrendered U-Boats in Norwegian (10) and German (25) ports. In the latter case, they were all located at Wilhelmshaven, having been transferred there from the Danish and other German ports where they initially surrendered in early May. These U-Boats were transferred directly to either Lisahally or Loch Ryan between 3 June and 30 June:

From Norway
3 Jun - from Horten 6 - (U-2502, U-2513, U-2518, U-3017, U-3041 and U-3515)
3 Jun - from Kristiansand (S) 1 - (U-2529)
6 Jun - from Bergen 1 - (U-3514)
17 Jun - from Bergen 2 - (U-2506 and U-2511)

From Germany
21 Jun - from Wilhelmshaven 6 - (U-883, U-2336, U-2341, U-2351, U-2356 and U-3008)
22 Jun - from Wilhelmshaven 4 - (U-155, U-806, U-1230 and U-1233)
23 Jun - from Wilhelmshaven 5 - (U-368, U-1102, U-1103, U-1110 and U-1194)
24 Jun - from Wilhelmshaven 5 - (U-291, U-680, U-720, U-779 and U-1198)
30 Jun - from Wilhelmshaven 5 - (U-143, U-145, U-149, U-150 and U-739)

These U-Boats were moved directly to Lisahally and Loch Ryan via the Pentland Firth sea route to the north of Scotland and, in many cases, were escorted by the RN ships which had been part of the Scapa Flow reception force. Evidence of the transfers was recorded in "The Scotsman" newspaper in June 1945, which reported that U-Boats had continued to reach Loch Ryan, and that on 10 June there were 52 in the Loch. Also, that two RN-crewed U-Boats from Norway had been diverted into Lerwick on 18 June because of a gale warning, that more U-Boats had arrived at Loch Ryan on 28 June, and that there were then more than 60 moored there.

The two U-Boats that had surrendered from sea in Gibraltar were transferred (U-485 - to Loch Ryan and U-541 - to Lisahally), as were the three that had surrendered from sea in Portland in the south of England (U-249 - directly to Loch Ryan, U-776 - to Loch Ryan after a tour of British east coast ports, and U-1023 - to Lisahally after a tour of British west coast ports). Also, the U-Boat that had been interned in Spain since September 1943 (U-760), but which was not part of the formal surrender process, was moved to Loch Ryan on 23 July.

There were also two U-Boats (U-1406 and U-1407) which, whilst they had surrendered in Cuxhaven on 5 May and been vacated by their crews, were then scuttled by a German naval officer on 7 May, making them unavailable for transfer to the UK as part of Operation Pledge. The officer concerned, Oberleutnant Gerhard Grumpelt, was subsequently tried by a British court in Hamburg, found guilty of disregarding the surrender agreement, and sentenced to five years in prison.

Finally, there were then just eight surrendered U-Boats remaining in continental ports, all of which were unseaworthy for transfer: one in France (U-510 - St Nazaire) and seven in Norway (U-310 (Trondheim), U-315 (Trondheim), U-324 (Bergen), U-926 (Bergen), U-995 (Trondheim), U-1202 (Bergen) and U-4706 (Kristiansand (S)). These eight U-Boats were in fact never transferred; either being scrapped or eventually being taken into use by their host Nations.


A total of 156 U-Boats surrendered either from sea or in ports at the end of the European War. Of these, nine had surrendered from sea in Canada, the USA and Argentina, eight of those in European ports were unseaworthy, and two had been scuttled in Germany just two days after their surrender. Thus 137 surrendered U-Boats were transferred to Lisahally and Loch Ryan to await decisions on their final disposal, of which - under the auspices of Operation Pledge - 33 were moved via Loch Eriboll and Loch Alsh, 64 were moved via Scapa Flow, and 35 were moved directly from Norwegian and German ports via the sea route to the north of Scotland. The remaining five were transferred independently, as was U-760 which had been interned in Spain since 1943.


  1. Many of the details in this article come from the post-Operation Report 3054/T.40 dated 9 June 1945 written by Captain M J Evans, RN who commanded the Royal Naval reception forces in Loch Eriboll and at Scapa Flow. A copy of the report is held in the Roskill Archive in Churchill College, Cambridge. Also, many relevant original documents are held in the UK National Archives at Kew in files ADM 116/5202, ADM 116/5512 and AIR 15/449. Additionally, an excellent and detailed description of the activities at Loch Eriboll between 9 and 28 May 1945 is contained in David Hird’s book "The Grey Wolves of Eriboll (2010)".
  2. Further details of the surrender and subsequent scuttling of U-1406 and U-1407 can be found in the UK PRO files ADM 228/8, WO 235/632 and WO 235/64. Also, a detailed report about Oberleutnant Grumpelt’s Court Martial can be found in “Law Reports of Trials of War Criminals, Vol, 1, English Edition”, HMSO, 1947.

This article was published on 25 Sep 2010.

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