The 240-mm Howitzer M-1 was a towed howitzer used during World War II by the U.S. Army. Commonly nicknamed the "Black Dragon," it was designed to replace the M1918 used during World War I which was based on a French design. The Black Dragon was the largest and most powerful field artillery piece used by the U.S. Army during World War II, with the exception of naval ordnance pressed into service as railway guns. It entered service in 1940 and saw its first operational use by the U.S. 5th Army at the Anzio beachhead in September of 1943. Besides its extensive use in the Italian Campaign and in the Pacific, the M-1 also had success against heavily fortified targets along the Siegfried Line. After the war the 240-mm howitzer M-1 was further pressed into service in the Korean War until the Army's stock of ammunition was depleted in the late 1950s. Heavy and unwieldy, the gun was hauled in two parts by a pair of 38-ton tractors -- the twelve and a half ton barrel on a six-wheeled transport wagon and the twenty ton split-trail carriage on another wagon. A truck mounted crane was needed to assist in the digging of the recoil pit and to pick up the carriage and the 27 foot barrel and set them into place. The 240-mm howitzer M-1 could hurl a 360 pound shell over 14 miles with a muzzle velocity of 2,300 feet per second. The gun took a crew of 14 to set up and operate and they could fire 2 to 3 rounds per minute. Set up could be acheived in about an hour and half.
"Biggest Guns On Wheels" Popular Science Monthly, July 1945