Submarines: How They Work - Archimedes' Principle

Because both were dangerous, steam and gasoline engines were phased out for less-volatile diesel engines. In 1904, the French became the first to build a submarine Aigrette, which used a diesel engine on surface and an electric engine while underwater. The U.S. followed the trend building its first diesel-powered sub, the F-class Skipjack, in 1911. The diesel engine supplied steam, which turned turbines to produce the electricity to heat, light and power the sub. These diesel engines burned oil instead of gas so they had less toxic fumes, were more economical and did not use a complicated sparking system. However, diesel engines could not be used underwater because they needed air for combustion and did produced some toxic fumes. Instead, electric batteries were used when a submarine was underwater..