M115 howitzer

The M115 203 mm howitzer, also known as the M115 8 inch howitzer, was a towed howitzer developed and used by the United States Army. Until the 1950s it was designated the 8 inch Howitzer M1. The original design started in 1919 but lapsed until resurrected in 1927 as a partner-piece for a new 155 mm gun. It was standardised as 8 inch Howitzer M1 in 1940. The M115/M1 was towed by the M35 Prime Mover gun tractor or a Mack 7 ¹⁄₃ ton 6x6 truck.

Like the British BL 8 inch Howitzer of the First World War, the M115 uses a Welin screw for its breech. The carriage was the same as used for the US 155 mm gun and was also adopted by the British for their 7.2 inch Mark 6 howitzer. It consists of equilibrator assemblies, elevating and traversing mechanisms, two single-wheel, single-axle heavy limber, two-axle bogie with eight tyres and two trails. Four spades, carried on the trails, are used to emplace the weapon. The British 8 inch howitzer was produced in England and under license in the US, for the American Expeditionary Forces in Europe during World War I, as the 8-inch Howitzer MK. VI. It was in service with the US Army till replaced by the M115. There are no reports of the MK. VI or another marks being used during World War II.