Discover the History of the Depth Charge

The depth charge or bomb is a waterproof weapon used by ships or aircraft to attack submerged submarines.

First Depth Charges

HMS Tempest dropping a depth charge
HMS Tempest dropping a depth charge.

The first depth charges were developed by the British in World War I for use against German submarines or U-boats, beginning in late 1915. They were steel canisters, the size of an oil drum, filled with TNT explosives. They were dropped off the side or stern of a ship, on top of where the crew estimated the enemy submarines were. The canister sank and exploded at a depth that was preset by the use of a hydrostatic valve. The charges often did not hit the submarines but the shock of the explosions still damaged the submarines by loosening the submarine enough to create leaks and forcing the submarine to surface. Then the naval ship could use its guns, or ram the submarine.

The first depth charges were not effective weapons. Between 1915 and the end of 1917, depth charges destroyed only nine U-boats. They were improved in 1918 and that year were responsible for destroying twenty-two U-boats, when depth charges were propelled through the air over distances of 100 or more yards with special cannons, increasing the damage range of the naval ships.

Depth Charge Projector

Depth charge projector
Depth charge projector.

During World War II, depth charges were further developed. The Royal Navy's Hedgehog depth charge could be launched to a distance of 250 yards and contained 24 small, high-explosive bombs that exploded on contact. Other depth charges weighing as much as 3,000 pounds were used in World War II.

Depth Charges During a Tour of Duty

A submarine's trials with depth charges
A submarine's trials with depth charges during a tour of duty.

Modern depth-charge launchers are computer-controlled mortars that can fire 400-pound depth charges up to 2,000 yards. Atomic depth charges use a nuclear warhead and other depth charges have been developed that can be launched from aircraft.

Allied Destroyer Dropping Twin Depth Charges

Allied destroyer dropping twin depth cha
Allied destroyer dropping twin depth charges.
  • USS PAMPANITO (SS-383): A submarine's trials with depth charges during a tour of duty.
  • USS Pampanito - DEPTH CHARGE RANGE ESTIMATOR (DCRE): The depth charge range estimator (DCRE) is a device which provides the submarine conning officer with an approximate estimation of the range of depth charge explosions in his vicinity based on the intensity of the sound received.
  • USS Pampanito - DEPTH CHARGE DIRECTION INDICATOR (DCDI): The depth charge direction indicator (DCDI) is a sonar device used to indicate to a submarine conning officer the general direction of depth charge explosions occurring in his vicinity.
  • Depth Charge Direction Indicator: Depth Charge Direction Indicator and its line filter from F. W. Sickles Co. Coast Guardsmen on World War II convoy patrol watch the explosion of a depth charge.

Depth Charge Operator

Depth Charge Operator
Depth Charge Operator.

Depth Charge Operator