The UUM-44A Submarine Rocket [SUBROC] was a large weapon designed to be fired from a standard 21" submarine torpedo tube. The SUBROC is about the length and diameter of a standard torpedo, so that it could be ejected from a submarine tube. Once ejected from a nuclear submarine’s torpedo tube, the weapon clears the ship and then the solid fuel rocket motor ignites coming out of the water. After breaking the surface the booster accelerates to a predetermined altitude and speed before separating from the payload and tumbling back into the sea, flying up to 25-30 miles to the computed impact point. At impact with the sea, it performed some underwater terminal maneuvers to close the predicted position of the intended target. Finally finding its target, a 39-inch long Mark 55 thermonuclear warhead, weighing approximately 460 pounds, was then detonated. A direct hit is not necessary.
Nuclear warheads to be disassembled through mid-1999 include the W55 for the SUBROC.