This was another attempt at producing a new breed of U-Boat so as an alternative to the Walter turbine drive of other experimental boats, Deschimag AG Weser in Bremen proposed diesel engines in a close-cycle system as early as 1943. This was nothing new, but the design study they put forth seemed workable. While they never did produce a submarine with this DESCHIMAG Project, the project was taken up at the same time as the TYPE XXI Walter turbine powered boats. This is what they were planned to be:

Displacement 352 tons
Length 118 feet
Beam 13’ 3”
Draft 13’ 3”
Drive single-shaft diesel/electric
Power (diesel) 3,000 hp using two Daimler-Benz 20 cylinder diesel engines
Power (electric) 50 hp
Speed (diesel surfaced) 15 knots
Speed (diesel submerged) 22 knots
Speed (electric) 4 knots
Fuel (diesel) 30 tons
Fuel (oxygen) 9.5 tons
Range not known
Tubes (fwd) two 21 inch (carried four torpedoes) (aft) none
Crew unknown
Depth of dive unknown