Long before the United States experimented with a tuna-shaped submarine, the Germans did. The V80 was an experimental, unarmed research sub (and therefore a perfect analog of Albacore) that was intended to test new technology in propulsion and hydrodynamics. First underway in 1939, it was never commissioned into the Deutsche Kriegsmarine, formally, but it was intended to show the way forward in submarine technology.
Indeed it did — but not in time to benefit the Germans.
The two revolutionary technologies in the V80 were air-independent propulsion and improved hydrodynamics, from using a streamlined, tuna-like shape. In addition to the attempt to lower the form drag on the vessel, great attention was paid to eliminating all the usual parasitic producers of turbulence on then-current boats: handrails, drain holes, rivets and plates and bulges. In addition to the main benefit, speed, the V80 demonstrated that a cleanup of the sub’s shape and skin could greatly reduce its sonar signature.
Its name came from Versuchs (test) and its displacement, 80 tons. It had bunkerage for 21 tons of concentrated (“High Test”) H2O2 which gave it a range of only 50 nautical miles at its ultimate top speed of 28 knots. It carried a crew of 4 and no arms at all.
The AIP installation used in the V80 was a hydrogen peroxide catalytic turbine. The engine, and the sub, were designed by rocket-engine and H2O2 expert Dr. Ing. Hellmuth Walter, whose fertile mind and sharp pencil also provided the rockets that drove the Me163 fighter jet and that were used as JATO boosters by German aircraft.
In the engine, the peroxide was exposed to a catalyst and produced an exothermic reaction that drove the turbine with the output gases: oxygen and steam (water vapor). With the efficient (for the day) engine and the sub’s special shape, the V80 set speed records — 23 knots in 1939.
Admiral Karl Dönitz immediately grasped the potential of this technology, and Walter went to work designing larger boats. There was, first, a double class of weaponized research vessels, the Type XVIIA and XVIIB boats. Then there was the Type XVIII. None of these was made in quantity, or in time, to have a combat impact.
After the war, these technologies were pursued for a while, but they had safety implications that ultimately sidelined them, especially after the advent of nuclear power. The Russians use peroxide propulsion for some torpedoes (which caused the loss of the submarine Kursk and its crew), and in recent years, air-independent propulsion has made a comeback.
Uboat.net. U-boat Types: The Walter Boats: The Walter U-boat Types. Retrieved from: http://uboat.net/types/walter.htm
Uboat.net. U-boat Types: The Walter Boats: V80. Retrieved from: http://uboat.net/types/v80.htm