240 mm Howitzer M1

The 240 mm howitzer M1 was a 9.45-inch heavy artillery piece in service with the US Army during World War II and the Korean War. It had been designed in 1940, based on the 240mm M1918 model, which in turn had been developed from the French 28-cm Schneider fielded by both the French and Russian Army. Introduced in 1943, it was used in combat for the first time in January 1944, during the Allied invasion of Italy, also in France and Germany after the landing on Normandy.

The 240 mm M1918 howitzer was too heavy and cumbersome to tow around as it traveled in several pieces and then it had to be painstakingly assembled by means of hoists and ropes at the firing point. Thus, the US Army dropped it, scrapping the 330 pieces that had been built, as it saw the urgent need of a new heavy artillery piece that was easier to set up and carry around. This is how they decided to develop a new one from scratch but based on the M1918 design and caliber. After several field tests and improvement, the new weapon was finally standardized in May 1943 as the 240-mm Howitzer M1. After a long service in the US Army, it would finally be phased out in 1959.

The 240 mm howitzer M1 was a very accurate and powerful weapon. It was fitted with an interrupted screw breech, with dropping block balanced by springs. It fired 163.6-kg (360-pound) shells to a maximum range of 23.14 km (25,225 yards), using a separate load charge. The howitzer was mounted on a split trail carriage. Towing was done by a 38-ton, tracked M6 vehicle or by heavy trucks on a semi-trailer. Upon arrival at the firing point, it was unloaded by means of winches on the tracked vehicle.

Specifications

Type: heavy howitzer

Caliber: 240mm (9.45 inch)

Total Weight: 29.348 tons (64,700-pound)

Shell: high explosive/separate load

Barrel Length: 8.41 m (331-inch)

Rifling: 68 grooves (right-hand twist)

Recoil System: hydro-pneumatic

Breech Type: interrupted screw

Elevation: +15 to +65 degrees

Traverse: 22.5 degrees

Muzzle Velocity: 701 m/s (2,300 ft/s)

Maximum Range: 23.14 km (25,225 yards)

Below, the 240-mm Howitzer M1 in 1943, when it entered service. No spades are fitted here as it is set up on a concrete gunpark

The 240 mm M1 in Korea, as part of the 213th FA Battalion, 45th Infantry Div., north of Yang-gu in 1953.

The first design of the heavy artillery piece, showing how the gun could be carried on a truck semi-trailer.

The 240 mm Howitzer M1 in Action in WW2 (video)