The T131 heavy motorized gun was the experimental model of the M65 atomic cannon. Adopted in 1956, the cannon could fire both nuclear and conventional shells over a range of 18 miles. Rendered obsolete by the development of more mobile rockets, the atomic cannon was withdrawn from service in the U.S. Army by the mid-1960s. Only eight cannons remain today. The cannon weighs 47 tons and is mobile. The prime mover consists of both a front and rear truck that can reach a maximum speed of 30 mph.

Historical Analysis

Atomic weaponry was a staple in military arsenals during the Cold War. During the early onset of the arms race in the 1950s, atomic projectiles were not yet being fitted on missiles, but rather appeared in the form of bombs. For the U.S. Army, however, where military tactics included the use of atomic weapons on and close to the front line, a weapon was designed to deliver an atomic artillery around behind the front lines. The demand for such a weapon led to the development of the M65 280MM Motorized Heavy Gun, also known as "Atomic Annie" or the Atomic Cannon.

Based on the "Anzio Annie" gun developed by Nazi Germany, the T131 280MM Gun was developed at Watervliet Arsenal, N.Y., in 1950 with the intention of loading it with a W-9 15 KT atomic projectile (T124). The T72 Gun Carriage was used to cradle the gun. Two 4x4 semi-trucks were required to move the gun into position. The truck at the front was designated M249, with the M250 at the rear. Both were manufactured by the Kenworth Truck Company.

The first tests began at the Aberdeen Proving Grounds in 1952. However, the first and only atomic round to be fired from one of the cannons occurred on 25 May 1953 with the "Grable" Shot, part of the Upshot-Knothole atomic tests. The test took place at the Nevada Proving Ground and the detonation of the warhead occurred at 524 feet above the target area.

With twenty guns produced, only a few have survived, including the one here at Rock Island Arsenal. The only complete unit with the semis known to remain is at the Aberdeen Proving Grounds.

Specifications

Weight: 83.3 tons
Range: 7-20 miles
Crew: 5-7
Variants: 2
Length: 84 feet
Width: 16.1 feet
Height: 12.2 feet
Shell Weight: 600 pounds
Caliber: 280mm
Yield: 15-20 kilotons