The Canon de 155 Grande Puissance Filloux (GPF) modèle 1917 was a WWI-era French-designed 155 mm gun used by the French Army and the United States Army during the first half of the 20th century in towed and self-propelled mountings.
The gun was designed during the First World War by Colonel Louis Filloux to meet an urgent need for modern heavy artillery and became the standard heavy field gun of the French Army from 1917 until the Second World War. It was also adopted by the United States as the M1917 and a close derivative of it was made in and used by the US as the M1918 through the Second World War.
The design adopted the split trail invented by French Colonel Deport in the early 1910s (see Cannone da 75/27 modello 11), and unlike the previous pieces, which had their carriages riveted from machined and/or pressed steel parts, utilized very large steel castings.
The gun was also manufactured in the United States from 1917, after the US switched to metric artillery based on French patterns. The castings became the main technological difficulty, with the work done by the Minneapolis Steel & Machinery Company.[1]
During the Second World War, some US-made guns were used for coast defense of US and Allied territories, such as Australia and Bermuda, typically on "Panama" mountings - circular concrete platforms with a raised centre section, with the carriage tires pivoting around the center section and the split trails spread out on rails at the edge of the platform.[2]
This gun was designed by Colonel L. J. F. Filloux to fill a vital French Army requirement for a heavy artillery piece. The design proved a success and became the standard heavy field gun of the French from 1917 to the end of World War I.[3] The weapon was pressed into service quickly, to remedy the shortage of such weapons in the French inventory. This weapon became the "Canon de 155 Grande Puissance Filloux mle 1917", named by French Army as the Canon de 155mm GPF (Model of 1917). The guns were produced by Atelier de Puteaux (APX), Renault and Atelier de Bourges (ABS).[4]
During the First World War, the gun was eventually taken on by the American Expeditionary Force as a standard long-range artillery piece.[5] At the beginning of the Second World War the French guns were still in service and more than 450 guns were operational in May–June 1940.[6][7]
The GPF-CA was a variant of the GPF that used a longer chamber (chambre allongée or CA). It was produced by Puteaux from 1918 to enable the firing of heavier shells.[4]
The US M1918 155 mm GPF was a copy of the French 1917 field gun and used by the US Army, Philippines and US Marines up to 1945.[8] The United States Army paid for and subsequently copied, the Model 1918 (M1918) gun. During the Second World War the 155 mm guns were taken out of storage and used for coast defense on American shores and in Allied territories such as the Philippines and Australia. They were also used in the Philippines, Guadalcanal and North Africa campaign until more modern artillery was available. Ultimately, both the US Army and Marine Corps phased out their M1918 guns for the 155 mm M1A1 "Long Tom" beginning in 1942. The M1918 was also fitted to the M12 Gun Motor Carriage as a self-propelled gun (SPG) and used from 1943 to 1945.
In 1939, Captain Touzard, French Army, proposed a new carriage for the GPF-T. It improved the mobility but also reduced the preparation time.[4] The GPF-T was heavier (13.7 tonnes (13.5 long tons; 15.1 short tons)) but could be towed at a speed up to 36 kilometres per hour (22 mph). Around 60 guns were in service in May 1940.[6]
Many of the guns fielded by the French in 1940 were captured and used by Germany for the rest of the war. In German service, the standard GPF version was known as the 15,5 cm K 418(f), the GPF-CA as the 15,5 cm K 417(f) and the GPF-T as the 15,5 cm K 419(f). It served with heavy artillery battalions in the Afrika Korps and on coast defense duties.[4][9] On D-Day in 1944, the German Army had over 50 of the 155 mm French guns in sites on the northern French beaches. A battery of six of these guns near four empty emplacements for larger guns was the cause of the actions at Pointe du Hoc in June 1944.[10][3]
^Berhow, Mark A., ed. (2015). American Seacoast Defenses, A Reference Guide (Third ed.). McLean, Virginia: CDSG Press. pp. 200–231. ISBN978-0-9748167-3-9.
van der Vat, Dan; Eisenhower, John S. D. D-Day: The Greatest Invasion—A People's History. Bloomsbury Publishing Plc, ISBN1-58234-314-4.
Gander, Terry and Chamberlain, Peter. Weapons of the Third Reich: An Encyclopedic Survey of All Small Arms, Artillery and Special Weapons of the German Land Forces 1939–1945. New York: Doubleday, 1979 ISBN0-385-15090-3
Touzin, Pierre; Vauvillier, François (2006). Les Matériels de l'Armée Française: Les canons de la victoire, 1914–1918. Tome 1: L'Artillerie de Campagne. Paris: Histoire et Collections. ISBN2-35250-022-2.
