Operation Deadlight

On 4 May 1945 Grossadmiral Karl Dönitz, who Hitler named as his successor as head of State shortly before he committed suicide, ordered all combat U-boats to cease offensive operations and return to their bases with a brief one-line message: ‘All U-boats cease fire at once. Stop all hostile action against Allied shipping. Dönitz.’ Generaladmiral Hans-Georg von Friedeburg, Dönitz’s successor as Commander-in-Chief of the Kriegsmarine, surrendered the German Navy at 11.10pm on 7 May 1945 at a ceremony held at Reims in Germany, followed by a repeat signing in Berlin the next day at the insistence of the Russians. The terms included the entire German fleet, but apart from the cruisers Prinz Eugen, Nurnberg and Leipzig, only 15 destroyers, 11 torpedo-boats, and two dozen minesweepers were all that remained of the Kriegsmarine’s surface fleet. During the course of the war the Germans had lost two battleships, two battlecruisers, three pocket battleships, two old dreadnought battleships of 1908 vintage, three heavy cruisers, four light cruisers, 44 destroyers, 56 torpedo-boats, seven armed merchant cruisers, 23 minelayers, 146 E-boats, 282 various sized minesweepers and over 850 other armed craft.

Surrender of the German U-boats
Attention turned next to the German submarines. Unknown to the Allies, in the last few days before the wars’ end, orders had gone out from Kriegsmarine headquarters under the code word Regenbogen for crews to commence scuttling their U-boats. By 8 May this had accounted for 195 sunk in this manner, however, excluding many that were unseaworthy and remained in French, German, Norway and Spanish ports, plus others that surrendered in Canada and the USA, this still left 156 to be sailed into British home waters and handed over under the surrender terms.
Under the Tripartite Naval Commission agreement of 1945, 30 submarines of the most recent types were to be divided equally between the UK, USA and USSR, whilst several others, assessed as unseaworthy, were left in their European ports. Germany’s underwater weaponry was eagerly seized and examined by the victors, particularly the revolutionary type XXI and XXIII Elektroboots. Apart from Europe, seven ex-U-boats had surrendered in the Far East in August 1945 under the Japanese flag, which had been commandeered whilst docked in Japanese ports when Germany surrendered three months earlier. The 156 boats that surrendered to the United Kingdom started to arrive in UK ports from 14 May 1945, escorted by Royal Naval vessels. For many naval and air force servicemen who had been involved in the U-boat war since 1939, this was their first glimpse of the actual vessels and their crews, and both sides were forced to exercise considerable restraint to avoid compromising the terms of Germany’s surrender. After the Allies had made their selections (for example U-3017 was commissioned into the Royal Navy as HMS N41 and was used for tests until it was scrapped in November 1949) this left a balance of 116 to be disposed of by sinking under the Tripartite Naval Commission terms, consequently they were transferred pending disposal to either Lishally in Northern Ireland, or to Loch Ryan in NW Scotland. The U-boat fleet was made up of 94 conventional boats and 22 of a secretive new type that Germany named Elektroboots.

 

 

Left: Surrender of the heavy Cruiser Prinz Eugen to British and Dutch naval authorities at Copenhagen on 12 May 1945

 

 

 

The Elektroboots
Until 1942, conventional U-boats enjoyed immense success attacking convoys at night whilst on the surface, making ASDIC ineffective in locating their position. As the war progressed, Allied radar-equipped aircraft, plus convoy escort carriers with their anti-submarine attack squadrons, reversed previous enemy successes, causing U-boat losses to suddenly escalate. This alarming situation led to a development meeting in November 1942 to examine the progress of a new German concept submarine. Two types were developed, a giant 250ft, 1,620t, type XXI (with a capacity for 23 G7e torpedos) and the smaller 114ft, 234t type XXIII coastal version, which had its only two torpedo tubes pre-loaded with no extra space for re-loads. In both cases a full length extra lower deck was given over to enhanced battery capacity, which allowed the Elektroboots to remain submerged for several days; recharging simply via the snorkel. With a modern-looking, streamlined hull that helped provide an underwater speed up to 18kn; power-assisted torpedo loading; the deck gun replaced by remote-controlled armoured flak turrets; the latest solar; twin detector and transmitting search radar; deep freeze for fresh food; increased crew comfort and the capability to fire 18 torpedoes in under 30 minutes, the design concept was ready by January 1943 and presented to Hitler that July for approval. Building was authorised on 13 August, but nobody in authority wanted to halt production of the conventional U-boats to suddenly switch to an unproved concept. Pressure to keep producing the earlier types was paramount due to their high loss rate.

 

 

Left: U-190 shortly after surrendering to the Royal Canadian Navy at St John’s, Newfoundland, 5 May 1945

 

It was not until March 1944 that the first Type XXI Elektroboot was laid down which, in retrospect, was a serious mistake, because a basic prototype had been produced as early as 1940 by Professor Helmuth Walter. Had their development not been delayed, Elektroboots might well have turned the tables during the Battle of the Atlantic, resulting in totally blockading Britain, plus a serious threat to sinking the packed US troopships crossing the Atlantic. Whilst 380 XXI’s and 95 XXIII’s were originally planned for May 1945, only two and six respectively were actually ready for combat before the war ended. In the case of U-2540, commissioned in February 1945, the boat was scuttled by its crew on 4 May having never ventured out. It was raised in 1957 and restored to its WWII configuration in 1984 and is now on display at Bremerhaven Maritime Museum Germany, the only floating example of a Type XXI U-boat.             

Operation Deadlight begins
Operation Deadlight was the Royal Navy code name for the remaining 116 U-boats to be sunk at sea between 17 November 1945 and 11 February 1946. On 31 October 1945 the Admiralty instructed Commander-in-Chief Rosyth, Vice Admiral Sir William Jock Whitworth, to commence arrangements to dispose of 30 boats at Lishally and 86 boats at Loch Ryan in deep water off the north coast of Ireland starting from 25 November. The U-boats comprised one Type IID, 76 Type VIIC, one Type VIID, one Type VIIF, 11 Type IXC, four Type IXD2, four Type XXI and 18 Type XXIII. The Royal Navy towed the unmanned boats out to sea, but things didn’t go entirely to plan. Bad weather caused 20 of the U-boats to founder on tow; the demolition charges failed except on two occasions; only 13 air-attack sinkings were effected instead of the planned 29; the torpedo exercise attacks were reduced from 13 to eight, leaving the balance of 73 submarines to be despatched by gunfire. In all, only 58 of the 116 U-boats reached the disposal area, the rest lie scattered in a line across the north coast of Donegal ranging in depth from 46m to 130m.

 

Left British naval armed guards look on as a German submarine rating carries torpedo parts from the surrendered U-826 at Loch Eriboll, Scotland                                                                                  

 

 

Unique value of the Deadlight U-boats
Because all 116 U-boats lying beneath the waves were constructed prior to when the two nuclear bombs were dropped on Japan in August 1945 and subsequent nuclear weapons testing during the Cold War, the wrecks contain metals that are not radioactively tainted, as are all metals produced since. Pre-August 1945 metals are called Low-background steel, because modern steel is contaminated with a weak radioactive signal, consequently Low-background steel is extremely valuable and needed to produce devices such as Geiger counters; sensitive medical instruments; scientific equipment; aeronautical sensors and for space exploration.

 

 

Right: Oberleutnant zur See Karl Jobst surrender’s his Type XXIII U-2326 under supervision of an armed RNVR officer. Taken over by the Admiralty, it later served as HMS N.35 until December 1946

 

Most of the sunken submarines lie in previously marked coordinates (see map) and because of objections from Russia and the United States, the Ministry of Defence were denied awarding any salvage rights, although it’s rumoured that this has changed since 1998. The boats are said to rest on the waterbed at depths of approximately 90ms and salvage of over 50 boats was considered feasible by the late 1990s. From 2001, nautical archaeologist Dr Innes McCartney, nicknamed the ‘U-Boat Hunter’, spent three years discovering, surveying and filming many of the wrecks, including the rare Type XXI U-boats U-2506 and U-2511. Magnificent images were captured of both, which still remain in excellent condition, now marked as important archaeological finds.
Dr McCartney provided a summary of his search for the last one to be found to War History Online on 4 February 2015, where he wrote: ‘During the Operation Deadlight Expeditions we aimed to find, record and identify some of the 116 U-boats. While many of them were standard types, there were among the Deadlight fleet a few of the more exotic designs; none more so, than the Type XXI U-boats on which we dived. While U-2511 had already been found, another we knew about had not and was one of the key expedition targets. It took over a month of diving, over a two-year period, to finally locate her. The discovery of U-2506, and what happened subsequently, has been a very memorable chapter in my career as an archaeologist and diver, but what a merry dance she led us! This was because U-2506 was one of the last to be disposed of and was towed out of Lishally on 5 January 1946. She was to be torpedoed by HMSM Templar at the designated sinking zone, but the tug used to haul the U-boat was HMT Saucy and en-route Saucy’s cable parted. The U-boat became unmanageable and the escorting warship, HMS Onslaught, sank her by gunfire. The important issue with U2506‘s sinking was that the tugs used were not equipped with electronic position fixing equipment, so when they filed the report as to how U-2506 sank, the position given was somewhat inaccurate’.

 

Left: An aerial photograph of 42 surrendered U-boats moored at Lishally, Northern Ireland in June 1945, awaiting disposal by sinking under the terms of Operation Deadlight          

 

 

 

Researching the Operation Deadlight U-boats
Renowned Kriegsmarine historian, Jak Mallmann Showell, has authored two very recent books that cover most of the U-boat types surrendered during Operation Deadlight.
Hitler’s Wonder U-Boats introduces the massive Type XXI that was planned to replace the conventional Atlantic U-boats that had seen service so far in the war, plus the Type XXIII, which was a smaller coastal version. The revolutionary Electro U-boats became the forebears of the Cold War’s much dreaded hunter-killer submarines. Frontline Books, 2018; 216pp; over 100 images; Amazon.co.uk price is £18.
Hitler’s Attack U-Boats describes the new generation of attack U-boats that had been introduced since Hitler came to power and covers Types II, VII and IX that had already become the workhorse of the Kriegsmarine’s submarine fleet and continued to put out to sea to attack Allied shipping right up to the end of the war. Frontline Books, 2020; 232pp; over 100 illustrations; Amazon.co.uk price is £25.

 

Left: This map plots the locations of 75 of the U-boats sunk by the Royal Navy and the RAF between late 1945 and early 1946 off Lishally, Northern Ireland (Uboat.net)

 

 

 

Left: Nicknamed the ‘U-boat Hunter’, Dr Innes McCartney is seen surveying a well-preserved U-boat wreck during the Channel 4 series The Wreck Detectives

 

 

 

 

 

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