The C-class blimp was a patrol airship developed by the US Navy shortly after World War I, a systematic improvement upon the B-type which was very suitable for training, but of limited value for patrol work. Larger than the B-class, these blimps had two motors and a longer endurance. Once again, the envelope production was split between Goodyear and Goodrich, with control cars being built by the Burgess division of Curtiss Aeroplane and Motor Company. Originally the Navy ordered 30 but reduced the number to 10 after the armistice in November 1918. All ten of the "C" type airships were delivered in late 1918, and examples served at all of the Navy's airship stations from 1918 to 1922. In 1921 the C-7 was the first airship ever to be inflated with helium. The Navy decommissioned its last two