The M115 was an American, 203mm heavy howitzer, which entered service in 1939 as the 8-in M1. It was used by the US Army in World War II, the Korean War, and the Vietnam War. It was exported to several countries, that included China, as it was also fielded by the nationalist forces, under Chiang Kai Shek, in the Chinese Civil War. In 1954, it was redesignated M115. During WWII, it was extensively employed in North Africa, Italy, France, the Low Countries, and Germany, playing an important role in the Battle of the Bulge. Since it was a very accurate and powerful weapon, it was used to put down heavy fire on strong enemy positions lying quite close to spearhead infantry units, providing in this way vital fire support to sustain an offensive. This heavy howitzer was also employed to wipe out enemy pillboxes and bunkers.
The M115 fired a 90.7-kg High Explosive shells up to a maximum range of 10 miles (16.6 km). Mounted on an M1 eight-wheeled, split-trail carriage, it was towed to the battlefield by the M35 gun tractor in WWII and Korea, and by a heavy truck in Vietnam. It was fitted with a hydropneumatic recoil system and an interrupted screw breech. Its muzzle velocity was 587 m per second. The howitzer was operated by a crew of 14 men. Weight: 15 tons. Elevation: -2º to +65º. Traverse: 60º.