The 155mm field gun was originally designed and built by France during World War I under the direction of Colonel L.J.F. Filloux's G.P.F. ("Grande Puissance Filloux"). The gun was designed to meet an important French Army requirement for heavy artillery.
The design ultimately proved successful and became the standard French heavy field gun from 1917 until the end of World War II.
The weapon was so successful that the U.S. Army funded the purchase and subsequently copied its design as the Model 1918 (M1918). The M1918 gun was mounted on a large 11,065-pound four-wheeled carriage and had a ground-mounted split tail for fire stability.
The split recoil design allows gun recoil ranges from 1.8 m/10 degrees to 1.1 m/28 degrees at altitude, and also allows firing at 60 degrees horizontal field and 0 degrees to 35 degrees elevation. On the road, the split rear is enclosed into a track and carried by a prosthetic carrier with gear brakes. Transportation is usually by tractor.
The carriage will be driven on paved roads and open terrain, so the benders are supported by semi-elliptical springs to absorb all road shocks.
The upper frame is a steel casting mounted on top of the lower frame to allow the gun to pivot when traversing; disc springs carry the weapon's load. However, when the gun fires, the spring is compressed and the tension is concentrated on the surfaces of the upper and lower slides. The landing gear is cast steel suspended from the axles by heavy-duty leaf springs. The main purpose of this design element is to support the superstructure; it also houses axles and hinges for trails.
The track is a "split" track made of steel beams with a lock that rotates along its front end to hold it in the open position. A lock is provided on the track when the gun is in the retracted tow position. The shovel is mounted on the tail end for stability in soft or hard ground and can be removed when the gun is in transport mode. The wagon wheels are cast steel and solid rubber tires, each with its own brake. Caterpillar cycling shoes are used on soft surfaces and simply slip over rubber tires.
They consist of twelve shoes that distribute the load weight over a given soft surface.
Use the "Quadrant View Panorama" system and sight glass to aim the weapon. The quadrant sight is mounted on top of the wagon's left trunnion for pitch. The aiming angle mechanism is mounted on the top of the quadrant, and a delete lever is provided for use with the panoramic sight. The sight glass is only used for direct fire or in emergency situations - when the latter can be mounted on a quadrant sight instead of a panoramic sight. A target light, an azimuth light, and cables and brackets for night vision are provided.
These fit in the included storage box on the sled.
The recoil mechanism is hydropneumatically variable. The mechanism consists of a piston, a piston rod and a control rod. The piston rod is attached to the breech lug and rebounds when fired.
The control rod has oil grooves that allow oil to flow along the rod to control the oil and reach the piston port during recoil. When the gun is raised through the arm and gear sectors, the piston rod rotates, reducing the recoil of the gun. A refill or gravity tank is installed with the recoil cylinder.
The tank holds 17 liters of superheated oil and ensures that the recoil cylinder is always full of oil.
French artillery was widely used by the Allies in Europe, and capture systems were also used by the Allies. The captured guns were renamed 15.5 cm K 418(f) by German units, where they served with heavy artillery battalions and as coastal defense weapons.
On D-Day in 1944, the Germans trained more than 50 French 155mm guns on the beaches of northern France, the most famous of which was the Pointe du Hoc - these were eventually destroyed in France by the US 2nd Ranger Battalion during the Allied invasion.
During World War II in the United States, the 155mm gun was taken out of storage and used for coastal defense along the coast of the United States and in the Allied regions such as the Philippines and Australia. These defensive guns were mounted on "Panama" mounts that allowed the guns to rotate on concrete columns, with separate tracks distributed on wheel rails that could roll around the columns for maximum flexibility when training the weapon against targets.
Eventually, beginning in 1942, both the U.S. Army and Marine Corps had the M1918 gun for the 155mm M1A1 "Long Tom" gun. The M1918 was also mounted on the M12 gun motor mount as a self-propelled gun (SPG) and was used from 1944 to 1945.
- fire support/attack/damage
19.69 ft (6 m)
14 tons (13,000 kg; 28,660 lb)
1 x 155mm barrel
Depends on the ammunition carrier.
Canon de 155mm GPF mle 1917 - French original design.
M1917/M1918 - American designation for the French Canon de 155mm GPF; used by both the US Army and the US Marine Corps.