U-977 mounted a single 3.7 cm Flakzwilling M42U gun on the rare LM 43U mount. The LM 43U mount was the final design of mount used on U-boats and is only known to be installed on. The 3.7 cm Flak M42U was the marine version of the 3.7 cm Flak, used by the Kriegsmarine on Type VII and Type IX U-boats.
Service history
U-977 was launched in March 1943. She was used in training and made no war patrols during her first two years of service. On 2 May 1945 she was sent on her first war patrol, sailing from Kristiansand, Norway, commanded by Oberleutnant zur See Heinz Schäffer. Schäffer's orders were to enter the British port of Southampton and sink any shipping there. This would have been a very dangerous assignment for a Type VII boat. When Admiral Dönitz ordered all attack submarines to stand down on 5 May 1945, U-977 was outbound north of Scotland.
Voyage to Argentina
Oblt.z.S. Schäffer decided to sail to Argentina rather than surrender. During later interrogation, Schäffer said his main reason was a German propaganda broadcast by Goebbels, which claimed that the Allies' Morgenthau Plan would turn Germany into a "goat pasture" and that all German men would be "enslaved and sterilized". Other factors were remembrances of the poor conditions and long delays that German POWs suffered through, in being repatriated at the end of World War I, and the hope of better living conditions in Argentina, which had a large German community. Schäffer offered the married crewmen the option of going ashore in Europe. Sixteen chose to do so and were landed from dinghies on Holsnøy island near Bergen on 10 May. U-977 then sailed to Argentina. Schäffer's version of the voyage states that from 10 May to 14 July 1945 she made a continuous submerged Schnorchel passage, "at 66 days the second longest in the war ". The U.S. Navy interrogated the crew and issued a report on 19 September 1945. The report does not mention a 66-day submerged voyage, but states that U-977 "made for the Iceland Passage on course 300° diving once on sighting a plane and once on sighting a ship: "she was also D/F'd many times late in May". According to the Navy report, the submarine stopped in the Cape Verde Islands for a short break, then completed the trip traveling on the surface using one engine. Crossing the equator on 23 July, she arrived in Mar del Plata, Argentina on 17 August after 99 days at sea from Bergen and a voyage of 14,157 km. These points agree with Schäffer's report that he stopped at Cape Verde Islands for a short break and crossed the Equator on 23 or 24 July 1945. Schäffer said that, after the short Cape Verde break, they completed the rest of the trip to Mar del Plata alternately on the surface and submerged. After surrendering to the Argentine authorities, as had happened to the crew of U-530, they were extradited to the US where they responded to the charge of having torpedoed the cruiser Bahia, and then to the UK, where they faced accusations that they had landed Nazi leaders in Argentina before surrendering. Schäffer was released in 1947. U-977 like U-530 was seized by the US Navy, and sunk during naval firing exercises, in its case in 1946, when it was used as a target.
In the arts
Schäffer later wrote a book: U-977 – 66 Tage unter Wasser, the first postwar memoir by a former U-boat officer. It was published in 1952, and was translated into English under the title U-boat 977. A documentary film directed by Nadine Poulain, Schäffer's granddaughter, was in the final stages of production in 2014.
