HMS Graph - Kriegsmarine Service

Kriegsmarine Service

The U-570 was commissioned into the Kriegsmarine on the 15 May 1941. After a series of short testing and commissioning trips in the Baltic, she moved to Norway where she carried out short training voyages and fired practice torpedoes. By 25 July, she had moved to the German U-boat base at Lofjord, part of Trondheimsfjord, around 13 kilometres (8 mi) north of Trondheim.

In late-August 1941, B-Dienst (the German naval codebreaking organisation) became aware of a large concentration of Allied merchant ships in the region of the North Atlantic south of Iceland. Admiral Karl Dönitz ordered sixteen U-boats to the area. The U-570 was to be one of these and, on the morning of 24 August, she put to sea on her first war patrol. Her planned mission was to patrol the area south of Iceland before proceeding to the U-boat base at La Pallice, France. She carried provisions for four weeks at sea.

The submarine was commanded by Kapitänleutnant Hans-Joachim Rahmlow. He was an experienced naval officer, but had only recently transferred to U-boats, having previously been a gunnery and coastal defences specialist. He had commanded the training submarine U-58, but had carried out no war patrols. Likewise, the First Watch Officer (second-in-command) had only served a few months with the U-boat branch, after serving on destroyers and the Second Watch Officer had little experience, having only recently been commissioned. The engineer was the only officer (and one of only four on-board) who had served on a U-boat war patrol. While the boat's petty officers had several years of navy service, many of the enlisted crew were still new to the German navy and had only a few months of U-boat training.

The U-570's inexperienced crew was not unique for the time. British interrogation of rescued crew-members of the U-501—sunk on her first patrol in September 1941—revealed that 41 out of 48 crew were on their first war patrol.