The Renault FT, frequently referred to in post-World War I literature as the "FT-17" or "FT17", was a French light tank that was among the most revolutionary and influential tank designs in history. The FT was the first production tank to have its armament within a fully rotating turret.[note 1] The Renault FT's configuration – crew compartment at the front, engine compartment at the back, and main armament in a revolving turret – became and remains the standard tank layout. Over 3,000 Renault FT tanks were manufactured by French industry, most of them during the year 1918. Another 950 of an almost identical licensed copy of the FT (the M1917) were made in the United States, but not in time to enter combat. Armoured warfare historian Steven Zaloga has called the Renault FT "the world's first modern tank."
The FT was designed and produced by the Société des Automobiles Renault (Renault Automobile Company), one of France's major manufacturers of motor vehicles then and now.
It is thought possible that Louis Renault began working on the idea as early as 21 December 1915, after a visit from Colonel J.B.E. Estienne. Estienne had drawn up plans for a tracked armoured vehicle based on the Holt caterpillar tractor, and, with permission from General Joffre, approached Renault as a possible manufacturer. Renault declined, saying that his company was operating at full capacity producing war materiel and that he had no experience of tracked vehicles. Estienne took his plans to theSchneider company, where they became France's first operational tank, the Schneider CA.
At a later, chance meeting with Renault on 16 July 1916, Estienne asked him to reconsider, which he did. The speed with which the project then progressed to the mock-up stage has led to the theory that Renault had been working on the idea for some time.
Louis Renault himself conceived the new tank's overall design and set its basic specifications. He imposed a realistic limit to the FT's projected weight which could not exceed 7 tons. Louis Renault was unconvinced that a sufficient power-to-weight ratio could be achieved with the production engines available at the time to give sufficient mobility to the heavy tank types requested by the military. Renault's most talented industrial designer, Rodolphe Ernst-Metzmaier, generated the FT's detailed execution plans . Charles-Edmond Serre, a long time associate of Louis Renault, organized and supervised the new tank's mass production. The FT's tracks were kept automatically under tension to prevent derailments, while a rounded tail piece facilitated the crossing of trenches . Because the engine had been designed to function normally under any slant, very steep slopes could be negotiated by the Renault FT without loss of power. Effective internal ventilation was provided by the engine's radiator fan which drew its air through the front crew compartment of the tank and forced it out through the rear engine's compartment.
Renault's design was technically far more advanced than the other two French tanks at the time, namely the Schneider CA1 (1916) and the heavy Saint-Chamond (1917). Nevertheless Renault encountered some early difficulties in getting his proposal fully supported by the head of the French tank arm, Colonel (later General) Jean Baptiste Eugène Estienne. After the first British use of heavy tanks on 15 September 1916 during the Battle of the Somme, the French military still pondered whether a large number of light tanks would be preferable to a smaller number of superheavy tanks (the later Char 2C). However on 27 November 1916, Estienne had sent to the French Commander in Chief a personal memorandum proposing the immediate adoption and mass manufacture of a light tank based on the specifications of the Renault prototype. After receiving two large government orders for the FT tank, one in April 1917 and the other in June 1917, Renault was at last able to proceed. However his design remained in competition with the superheavy Char 2C until the end of the war.
Crew locations shown with panels open
The prototype was refined during the second half of 1917, but the Renault FT remained plagued by radiator fan belt problems throughout the war. Only 84 were produced in 1917 but 2,697 were delivered to the French army before the Armistice.
About half of all FTs were manufactured in Renault's factory at Boulogne-Billancourt near Paris, with the remainder subcontracted to other concerns. Of the original order for 3,530, Renault accounted for 1,850 (52 per cent), Berliet 800 (23 per cent), SOMUA (a subsidiary of Schneider & Cie) 600 (17 per cent), and Delaunay-Belleville 280 (8 per cent). When the order was increased to 7,820 in 1918, production was distributed in roughly the same proportion. Louis Renault agreed to waive royalties for all French manufacturers of the FT.
Attempts to manufacture in USA
When the USA entered the War in April 1917, its army was short of heavy materiel, and had no tanks at all. Because of the wartime demands on French industry, it was decided that the quickest way to supply the American forces with sufficient armour was to manufacture the FT in the USA. A requirement of 4,400 of a modified version, theM1917, was decided on, with delivery expected to begin in April, 1918. By June 1918, US manufacturers had failed to produce any, and delivery dates were put back until September. France therefore agreed to lend 144 FTs, enough to equip 2 battalions. No M1917s reached the American Expeditionary Forces (AEF) until the War was over.
US Army operating FTs on the Western Front, 1918.
The first turret designed for the FT was a circular, cast steel version almost identical to that of the prototype. It was designed to carry aHotchkiss 8mm machine gun. In April 1917 Estienne decided for tactical reasons that some vehicles should be capable of carrying a small cannon. The 37mm Puteaux gun was chosen, and attempts were made to produce a cast steel turret capable of accommodating it, but it was unsuccessful. The first 150 FTs were for training only, and made of non-hardened steel plus the first model of turret. Meanwhile, the Berliet Company had produced a new design, a polygonal turret of riveted plate, which was simpler to produce than the early cast steel turret. It was given the name "omnibus", since it could easily be adapted to mount either the Hotchkiss machine gun or the Puteaux 37mm with its telescopic sight. This turret was fitted to production models in large numbers. In 1918 Forges et aciéries Paul Girod produced a successful circular turret which was mostly cast with some rolled parts. The Girod turret was also an "omnibus" design. Girod supplied it to all the companies producing the FT, and in the later stages of the war it became more commonplace than the Berliet turret. The turret sat on a circular ball-bearing race, and could easily be rotated by the gunner/commander or be locked in position with a handbrake.