German U-Boat V80 type V with propulsion turbine Walter in WW2

The V-80 (German: Versuchs-U-Boot V 80) was a 76-ton experimental submarine and the only representative of the German Type V design produced for Nazi Germany’s Kriegsmarine.
The prototype was completed in 1940 in Friedrich Krupp Germaniawerft in Kiel. The four-man vessel was designed to test the Walter hydrogen peroxide-based turbine propulsion system.
Its range was 50 nmi (93 km; 58 mi) at 28 knots (52 km/h; 32 mph)