 Royal Navy Coastal Motor Boats of World War I used a rear-facing trough and a cordite ram to push the torpedoes into the water tail-first; they then had to move rapidly out of the way to avoid being hit by their own torpedo.Developed in the run-up to the First World War, multiple-tube mounts (initially twin, later triple and in WW2 up to quintuple in some ships) for torpedoes in rotating turntable mounts appeared.Destroyers could be found with two or three of these mounts with between five and twelve tubes in total.