|A Chief About to Launch Two Depth Charges|
Although the British basically invented the depth charge—which was the most effective anti-submarine weapon—the U.S. Navy contributed significantly by improving the hydrostatic detonator, developing the depth charge rack (enabling depth charges to be rolled off the stern, instead of craned off in a net) and developing the “Y-gun,” enabling smaller depth charges to be fired abeam and ahead of the ship—reducing the target U-boat’s chance of escape.
Y-guns were developed by the U.S. Navy's Bureau of Ordnance from the British single-launch Thornycroft thrower and became available in 1918. Mounted on the center-line of the ship with the arms of the Y pointing outboard, two depth charges were cradled on shuttles inserted into each arm. An explosive propellant charge was detonated in the vertical column of the Y-gun to propel a depth charge about 45 yd (41 m) over each side of the ship. The main disadvantage of the Y-gun was that it had to be mounted on the center-line of a ship's deck, which could otherwise be occupied by superstructure, masts, or guns. The first were built by New London Ship and Engine Company beginning on 24 November 1917.
|The Double Launch Leaves the Ship|
The lighter, more easily loaded, single-action K-gun, standardized by the U.S. Navy in 1942, replaced the Y-gun as the primary depth charge projector for the Second World War.
Sources: U.S. Navy; Wikipedia