random notes

Submarine - Wikipedia, the free encyclopedia: "anaerobic propulsion was first employed by the Spanish Ictineo II in 1864. Ictineo's engine used a chemical mix containing a peroxide compound to generate heat for steam propulsion while also providing oxygen for the crew. The system was not employed again until 1940 when the German Navy tested a system employing the same principles, the Walter turbine, on the experimental V-80 submarine and later on the naval U-791 submarine. At the end of the Second World War the British and Russians experimented with hydrogen peroxide/kerosene (paraffin) engines which could be used both above and below the surface. The results were not encouraging enough for this technique to be adopted at the time, and although the Russians deployed a class of submarines with this engine type code named Quebec by NATO, they were considered a failure. Today several navies, notably Sweden, now use air-independent propulsion boats which substitute liquid oxygen for hydrogen peroxide.

The German Type 212 submarine uses nine 34-kilowatt hydrogen fuel cells as air-independent propulsion, which makes it first series production submarine using fuel cells."