It has been noted elsewhere that the French Army believed, from 1915, that mechanising the movement of artillery was a necessary condition to be able to mount successful offensives on the Western Front. An approach to moving artillery is to carry the guns "en portee" on the deck of a vehicle. This has some advantages over towing since a towed gun may bog or suffer damage from the tow. However, the size of guns carried is limited to field guns and light howitzers since a vehicle to portee heavy artillery would be so large and cumbersome that it would be useless on the battlefield.

At the end of 1915, Louis Renault was asked by the French Ministry of Munitions to develop a design for a "land battleship". Renault believed that his production capacity was overstretched at that time and the only proven track system, the Holt system, was not available to Renault because of the Holt patents and that Schneider had an exclusive licence for, in France. The issue of liability was cleared away by the French Govt who declared that the Holt patents did not apply to the Renault design of 8 wheels on 3 bogies but did apply to the Schneider design of 7 wheels on 2 bogies.

The Renault tank was never built but a related design - the "carrier caterpillar" was promising enough to be placed in production. An order of 50 machines was placed on 22 Sept 1916. This order was increased to 350 machines on 27 October 1916. The first Renault FP carriers were delivered in March 1917. It was intended that a section of 8 carriers could transport in one trip a complete gun battery of 4 field guns or howitzers, supplies, ammunition and 40-50 officers and men. The Renault FP was capable of carrying 75mm Mle 1897 field gun and limbers, 105mm L Mle 1913 Schneider gun and the 155mm C Mle 1915 Schneider howitzer.

The Renault FP was a very simple design, consisting of the Holt-like suspension, a flat deck and powered by an 11 litre Renault aero-engine of 110 ps at 1200 rpm driving through a 4-speed gearbox. The only items above the deck were the minimal seat and controls, the radiator and fuel tank. The Renault FP weighed 14t and could carry a max. load of 10t. The max. speed (unloaded) was about 6 kph. The use of an aero-engine proved to be problematic since the engine had high fuel consumption and required very frequent maintenance. The vehicle was rather bulky and fragile so care had to be taken with route planning and driving it.

By the end of 1917 some 120 Renault FPs were in service. They proved to be very successful and often were diverted from their primary role of artillery transport to act as tow vehicles for heavy artillery, general supply vehicles and even as tank transporters for Renault FT tanks. By the Armistice in Nov 1918 the French Army has 256 Renault FPs on strength.

Before the end of the war there were proposals to upgrade the Renault FP to carry a complete 155mm GPF gun (11 t). A large winch was added with sufficient capacity to pull a GPF onto the deck. A somewhat similar proposal was to turn the Renault FP into an SPG by attaching a wheelless GPF gun to the deck. Although the portee GPF was prototyped it was decided that the GPF gun would be towed by Schneider CD tractors rather than being carried.

The Renault FP does not appear to have remained in service for long after the Armistice. The directive of Gen. Herr, Inspector General of Artillery, in Nov 1918, that medium calibre heavy artillery should only be towed by tracked vehicles meant the end of tracked portee vehicles and light/medium self-propelled guns in the French Army for many years.

None known

A set of printable files for a 1:72 commercial STL model is available from: https://www.wargaming3d.com/product/wargame3d_renault_fp_artillery_tractor_1_72_france_ww1_

François Vauvillier "Des Tracteurs à Chenilles pour l'Artillerie II - Les Caterpillars Porteurs Renault FB et Schneider CD3" in "Histoire de Guerre Blindés & Materiel" No. 87, Avril-Juin 2009, pp. 80-87.
The old article on landships.freeservers by Tim Rigsby provided some of the images used.