280mm Atomic Cannon (Signal Corps photo #507087) On 19 May 1955, crew members of the 280mm atomic cannon prepare to demonstrate the weapon to 15 State Adjutant Generals at Ernst Ludwig Kaserne, Darmstadt. The generals are on an 11-day tour of military installations in Europe. (Webmaster note: Cannon and crew probably belong to the 216th FA Bn which has just arrived in Germany.)