The .30 cal water-cooled browning is a heavy machine gun designed by John M. Browning throughout the early 1900’s. A patent was first filed in 1900 for a recoil-powered automatic gun but the prototype was later built in 1910. First introduced in 1917, the United States armed forces used it in WWI, WWII, and the Korean War as it was used in service until the late 1960’s. It was used as a battalion level, and often mounted on vehicles such as a jeep.
The water-cooling system required the jacket surrounding the barrel be filled with water. When the barrel heated, the water-evaporated , turning into steam. The resulting steam moved off by a tube to a condenser container that not only allowed for the location of the gun to be concealed, but also enabled the re-use of water.