240mm Howitzer M1 ‘Black Dragon’

The 240mm Howitzer M1 was produced as part of a project to produce a mounting that could carry that or a 8in Gun, and saw service in Italy and in north-western Europe, although its lack of mobility reduced its usefulness.

During the First World War the US Army had been interested in the French 280mm howitzer, and this entered licensed production in the USA in 1918-19 as the 240mm Howitzer M1918.

240mm Howitzer M1 on Cassino Front, 1944

The original idea of a single mount for a 203mm (8in) and 240mm gun was originally suggested by the Westervelt Board of 1919, which produced a plan for the development of US artillery after the First World War. However this proposal was delayed and then dropped while the US Army attempted to produce an improved version of the 240mm Schneider design. Trials of the M1918 in 1925 suggested that a new weapon was needed, but work on the new design didn’t begin until 1934, and even then it was limited to a new carriage to allow the M1918 to be towed by motor vehicles.

The project for a new weapon was resurrected in April 1940, as the war clouds gathered in Europe. This time the idea of using the old weapon was abandoned, and the new carriage was to be combined with entirely new weapons. The 8in Gun proved to be more difficult than expected, but the 240mm Howitzer project made quicker progress.

The new carriage was based on the Carriage M1, produced for the 155m Gun M1/ M1A1/ M2. This was a heavy split trail carriage, which allowed for a good range of elevation and traverse, and produced a stable gun platform. However the increased weight of the 240mm Howitzer meant that the weapon could only be moved in two loads. The carriage was given six wheels, which had to be removed before the weapon could be emplaced. For any long distance movement the barrel was carried on a separate trailer. A number of different systems were examined for long distance transport. The first idea was to carry it on a 4-wheeled Howitzer Transport Wagon T2, but the new weapon was too heavy for this. The next plan was to use a Heavy Carriage Limber T4 connected to a T22 tractor, but this didn’t work well either. Eventually two three-axle carriage transport wagons were produced, the M2 and M3, and in May 1943 the howitzer and carriage was standardized as the 240mm Howitzer M1 on Carriage M1. The weapon was split into two loads - the gun and the carriage, one on each of the transport wagons.

M33 Prime Mover tows 240mm Howitzer, Italy, 1944

The howitzer used a screw breech with a dropping block, balanced by springs, and similar to the breech of the 16in gun.

A number of attempts were made to improve the weapons mobility. This included the M1E1 carriage, which was moved by the T17E1 transport wagon, which had two tracked suspension limbers, one mounted at each end of the carriage. Each of these had a single medium tank bogie on each side, with a raised front idler and large road wheel at the rear.

The M2 transport wagon was replaced with the T16E1 cannon transport wagon, which had three medium tank bogies on each side, to reduce ground pressure, and raised idler wheels at each end. Once again the weapon had to be split into two loads, with the carriage moving on the T17E1 and the barrel on the T16E1.

A battalion of six howitzers with the new system was tested in combat during the battle of Manila during the return to the Philippines.

240mm Howitzer firing, Fifth Army, Italy, 1944

Production actually began in November 1942, but only six were built that year. Another 57 were completed in 1943, 158 in 1944 and 94 in 1945.

In at least one respect the 240mm Howitzer was a throwback to the heavy artillery of the First World War. Before it could be emplaced a large pit had to be dug, to provide the space for the barrel to recoil when fired at high elevation. A 20 ton Loraine mobile crane was used to lift the carriage into place, and then to mount the barrel on top. It could take up to eight hours to emplace the gun. As a result it could only be used during more static periods of warfare, as it would take too long to get it into action during periods of mobile warfare.

The 240mm Howitzer saw service in Italy, where there were plenty of periods of static warfare as the Allies attempted to break through a series of German defensive lines. Originally the Fifth Army hadn’t really been interested in the weapon, believing that the 155mm Gun was as powerful a weapon as they would need. However once the 240mm Howitzer was actually in use its ability to destroy targets at longer range became of obvious value, and by 1944 it was seen as the ‘the most generally satisfactory weapon’ in service.

There were also plenty of times when it was of great value during the fighting in Normandy and along the German frontier, and most of the battalions equipped with the 240mm howitzer fought on that front. When it was used, the 240mm Howitzer M1 was an effective weapon, firing a very destructive shell to an impressive 23,093m. It was used by the British and American armies, before being withdrawn from service towards the end of the 1950s. 

Twenty one 240mm howitzer artillery battalions were forced during the Second World War, with fifteen serving in Europe and five in the Pacific (mainly on the Philippines).  

Twenty eight 240mm howitzers were requested by Britain under the lend-lease scheme, although it isn’t clear how many were delivered.

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