Type XVII submarine

Class of German U boat

The Type XVII U boats were small coastal submarines that used a high test peroxide propulsion system, which offered a combination of air independent propulsion and high submerged speeds.

In the early 1930s Hellmuth Walter had designed a small, high speed submarine with a streamlined form propelled by high test peroxide (HTP) and in 1939 he was awarded a contract to build an experimental vessel, the 80 ton V 80 was launched in ., which achieved an underwater speed of during trials in 1940. In November 1940 Admirals Erich Raeder and Werner Fuchs (head of the Kriegsmarines Construction Office) witnessed a demonstration of the V 80; Raeder was impressed, but Fuchs was slow to approve further tests. Following the success of the V 80's trials, Walter contacted Karl Dönitz in January 1942, who enthusiastically embraced the idea and requested that these submarines be developed as quickly as possible. An initial order was placed in summer 1942 for four Type XVIIA development submarines.

Of these, U 792 was launched in and U 793 was launched in ., designated Wa 201, were built by Blohm + Voss, achieved submerged. The other pair of Type XVIIA submarines, U 794 was launched in and U 795 was launched in ., designated Wk 202, were constructed by Friedrich Krupp Germaniawerft, Kiel. The U 793 achieved a submerged speed of in March 1944 with Admiral Dönitz aboard. In June 1944 U 792 achieved over a measured mile. The Type XVIIA submarines were found to be very hard to handle at high speed, and were plagued by numerous mechanical problems, low efficiency, and the fact that a significant amount of power was lost due to increased back pressure on the exhaust at depth. Also, the length to beam ratio was too low, resulting in an unnecessarily high drag. Construction of operational Type XVII submarines – the Type XVIIB – was begun at the Blohm + Voss yard in Hamburg. The Type XVIIB, unlike the XVIIA, had only a single turbine. The initial order was for 12 submarines, U 1405 through U 1416. However, Blohm + Voss were already struggling to cope with orders for Type XXI submarines and the Kriegsmarine reduced the order to six.

Twelve Type XVIIG of slightly improved design, U 1081 through U 1092, were at the same time ordered from Germaniawerft. A further three boats (U 1408 to U 1410) were under construction, but were not complete when the war ended. Another six Type XVIIB's (U 1411 to U 1416) were cancelled during the war in favour of the Type XXI submarine. At the Potsdam Conference in July 1945 U 1406 was allocated to the United States and U 1407 to Britain, and both were soon salvaged. The uncompleted U 1408 and U 1410 were discovered by British forces at the Blohm + Voss yard in Hamburg. The Royal Navy repaired U 1407 and recommissioned her on 25 September 1945 as She served as the model for two further HTP boats, and .