Depth charge (ordnance)
A depth charge ( ) is an underwater weapon that is used to destroy armed forces in an underwater situation and other underwater objects (such as submarines , anchor mines, ground mines, approaching torpedoes , combat swimmers, etc.). It consists of an explosive charge that is detonated underwater by a fuse at a predefined depth .
history
The first usable depth charges were developed by the Royal Navy during World War I to combat German submarines.
In addition to fighting underwater objects, depth charges were also occasionally used to sink ships during the Second World War . This was the case when a ship damaged by other combat operations (usually a merchant ship hit by submarine torpedoes) was to be destroyed by an escort vehicle after the crew had been evacuated in order to prevent the enemy from capturing the damaged ship. For this purpose, the escort vehicle (usually a destroyer or a corvette) passed the damaged freighter and dropped one or two depth charges towards the rear and side of the target. In such cases, these were set so that the detonation occurred even in shallow water. The pressure wave of the detonation tore open the hull of the freighter from below and caused the ship to sink. The ship throwing the depth charge had to pass quickly so that it would be at a safe distance when the slowly sinking bomb exploded.
The depth charge most frequently used by the Allies in World War II was the British type Mark VII, a barrel-shaped body 76 cm long and 47 cm in diameter with around 130 kg of TNT ( trinitrotoluene ). The deadly radius against submarines was 12 meters - at this distance the damage was so severe that the submarine either sank or had to surface. At a distance of 6 meters or less, the pressure hull was blown, which then led to the immediate loss of the boat. By using Minol (40% TNT, 40% ammonium nitrate and 20% aluminum powder) instead of TNT from 1942, the radius increased to 16 and 8 meters, respectively.
Depth charges can contain conventional explosive charges or nuclear charges. A distinction is made between conventional and reactive depth charges.
- Conventional depth charges are usually unrolled from racks on the deck of ships. In some cases, launching devices are also used, which eject the bombs to the side at a short distance. Special depth charges can also be dropped from aircraft.
- Reactive depth charges can be fired from depth charges individually or in volleys (range of depth charges is between 50 m and 6,500 m). In order to achieve stable flight and a greater rate of descent when immersed in the water, reactive depth charges have a flow-favorable shape and ring tail units. They are set in motion by the thrust of an engine or by a propellant charge . Usually unguided reactive engines based on two-component powder ( ballistite and cordite powder ) are used.
The following can be used as detonators:
- Pressure detonators that respond when a certain water pressure is reached (i.e. at a certain water depth) - the most common type of detonator.
- Impact detonators that respond when they hit an object.
- Distance fuse that responds shortly before it hits an object.
- Magneto , which under the effect of caused by the submarine magnetic field and the disturbance of the terrestrial magnetic field responsive.
- Time detonators that trigger after a preset time.
