He was also a recipient of the coveted (German: Ritterkreuz des Eisernen Kreuzes mit Eichenlaub). The Knight"s Cross of the Iron Cross and its higher grade Oak Leaves was awarded to recognise extreme battlefield bravery or successful military leadership. Lange served as 1st Watch Officer on U-431 from 15 December 1941 to 30 June 1942.
He went on three war patrols on U-431 under the command of Wilhelm Dommes.
U-711 under the command of Lange attacked and sank the HMS Bluebell on 17 February 1945. On 4 May 1945 U-711 was damaged in Operation Judgement, an attack by the Fleet Air Arm of the Royal Navy at Kilbotn aimed at the depot ships Black Watch and Senja, and sank after attempts by Lange and seven other crew members to keep it afloat.
The rest of the crew, who had gone on board Black Watch, did not survive. Only a few hours earlier Lange had received the signal from Germany ordering all U-boats to cease attacks on allied shipping with immediate effect.
He was interviewed in 2008 at the age of 92 for a book published in Norway which also contains information from Norwegian and British eyewitnesses.
The book also reveals that Lange took U-711 on patrols far along the Arctic coast of North Russia, past Novaya Zemlya and into the Kara Sea. Isachsen"s book describes how Lange was awarded the Oak Leaf Clasp by his commanding officer, who had no spares and presented Lange with one of his own. The wreck of U-711 was filmed in 2007.
In October 1957 Lange joined the Bundesmarine.
Here he took part in the construction of a new German U-boat force within North Atlantic Treaty Organization. Foreign two years he commanded the 1. Ubootgeschwader (1st Submarine Squadron) and in January 1964 became commander of the entire U-boat force.
Later he held several staff positions, ending his second naval career in 1972 as staff officer in the Marinedivision der Nordsee (naval forces in the North Sea). Bibliography.