The early device would consist of a large metal tube, preferably copper due to its high thermal conductivity, which would be placed in a furnace.
In theory, da Vinci believed the water would rapidly expand into vapour, blasting the projectile out of the front of the barrel.
In 1826–29, a 17.5 mm bore experimental steam cannon was developed by Colonel Karelin of the Imperial Russian Corps of Communications.
A successful World War II steam cannon was the Holman Projector, which was used to launch explosive Mills bombs into the air to create a defensive barrage against low-flying enemy aircraft.
After a successful defence of the SS Highlander in August 1940, downing two Heinkel floatplanes, there was a demand for more projectors to be fitted to small naval trawlers.