The first submarines were propelled by humans. The first mechanically driven submarine was the 1863 French , which used compressed air for propulsion. Anaerobic propulsion was first employed by the Spanish "Ictineo II" in 1864, which used a solution of zinc, manganese dioxide, and potassium chlorate to generate sufficient heat to power a steam engine, while also providing oxygen for the crew. A similar system was not employed again until 1940 when the German Navy tested a hydrogen peroxide-based system, the Walter turbine, on the experimental V-80 submarine and later on the naval and type XVII submarines; the system was further developed for the British , completed in 1958.