During the Cold War, the U.S. military had developed an ultimate weapon that could have changed the course of history, the M65 280mm Motorized Heavy Gun, affectionately called “Atomic Annie.” The tremendous artillery could fire nuclear artillery shells of a yield comparable to the bomb dropped on Hiroshima.
Introduced in 1952, Atomic Annie represented an engineering marvel in her time. Weighing 47 tons with the two 4×4 semi-trucks required to transport the cannon, it could reach a speed of 30 mph. Its operation required a crew of five to seven soldiers, and each unit cost $800,000 at the time, the equivalent of almost $8.9 million today.
The M65 was inspired by the German Krupp K5 “Anzio Annie,” a gigantic railway gun used in World War II, but Atomic Annie differed from its German counterpart in that it could fire a nuclear shell. The cannon’s only test firing came on May 25, 1953, during Operation Upshot-Knothole at the Nevada Test Site. Although the test was codenamed Grable, it detonated a 15-kiloton nuclear shell 8 miles away, showing the cannon’s real potential for devastation.
Subsequently, the development of such battlefield nuclear weapons was supported by President Dwight Eisenhower, who insisted on a nuclear-based army as a way to cut defense costs. Because of the rapid development of atomic bombs, only 20 units of the M65 were produced, and they never saw combat. The rapid development of nuclear weapons meant that the M65 was soon obsolete, and it was withdrawn in 1963.
Today, only eight of these gigantic cannons exist, with one being housed at the Smithsonian and the original Atomic Annie that fired the test shot on display at Fort Sill. The story of Atomic Annie serves to illustrate a telling point: it represents the extremes to which nations went during the Cold War to prepare for a potential nuclear conflict.