Anti-Submarine Rocket (ASROC)

The Anti-Submarine Rocket (ASROC) is a ballistic missile designed to deliver the Mk 46 torpedo to a water entry point. Navy surface ships employed the ASROC with two different payloads -- either a nuclear depth charge that used a W-44 nuclear device or the Mk-44 or Mk-46 lightweight acoustic torpedo. The ASROC weapons were relatively small devices designed to fit inside the distinctive eight-cell box launcher found on almost all cruisers and destroyers of the 1960's-1980's. The rockets were about fifteen feet long, approximately thirteen inches in diameter, and weighed about a ton. The torpedo is a very sophisticated weapon, employing for its time, state of the art technology for the propulsion and guidance systems. The torpedo is about eight feet long, weighs about 600 pounds and is also carried in tubes on escort ships. After water entry, the torpedo powered up and chased the sub using either passive or active sonar.

The nuclear depth charge configured ASROC on the other hand was a relatively simple device, as it was nothing more complicated than a ballistic, unguided rocket with a depth charge as payload. When employing either weapon, the idea was to place the weapon as close to the predicted position of the enemy sub and let the weapon work as designed. In the case of the depth charge, after water entry, it simply sank and detonated at a preset depth. The resulting shock wave did the rest -- water doesn't compress, but sub hulls do.

The ship-fired, ASROC-delivered nuclear torpedo was parachute deployed before entering the water and searching for and finding the submarine target. The torpedo, moving at 40 knots until reaching the proper depth in the water, then began a horizontal movement toward the target. Once in place, the warhead detonated. SWORDFISH was a low-yield nuclear weapon test (less than 20 kilotons) of an antisubmarine rocket (ASROC) delivery system conducted 11 May 1962, about 370 miles off San Diego, by USS AGERHOLM (DD-826). The underwater test produced a spectacular eruption on the ocean surface. Operation Sailor Hat involved using numerous conventional explosives to simulate nuclear blasts. Delta, the last Sailor Hat test in the ship evaluation program, was conducted to study seismological data, underwater acoustics, radio communications, cratering, air blast effects, cloud growth, fire ball generation, and electromagnetic data.

ASROC was housed in a MK 112 eight-barrel ready service launcher or in the ASROC storage magazine on the 01 level , Port side for Gearing class cans. The MK 112 launcher was divided into four double guides, each housing two missiles, or the equivalent of four cells. Each cell was temperature controlled to prevent weapon overheating and could be elevated to a 45 degree angle to the horizontal for firing.

Conventional Weapon Characteristics

Length: 192 inches
Diameter: 14.1 inches (body)
Weight: 1408 pounds
Power Plant: Solid Propellant Rocket
Warhead: MK 46 Torpedo
Guidance: Terminal Acoustic Homing with MK 46 Torpedo

USS Ozbourn DD846 fires a conventional ASROC at left while USS Agerholm DD826 fires a nuclear depth charge at right
Ozbourn/Agerholm

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