In 1934 requirements were sent out for a tank to replace the FT-17. Compagni Général de Construction des Locomotives, Delaunay-Belleville, FCM, and Renault submitted designs.
In May 1935 an order of 300 of the Renault models (known as the Renault ZM) were selected for production. Even with urgent construction the R-35 never replaced the FT-17 as only 1,600 were available by 1940. These were to equip 23 battalions before the German invasion. It was based on the Automitrailleuse de Reconnaissance 1935 Type ZT that was designed for the cavalry. The suspension and running gear were similar.
The prototypes of the R-35 were still being tested when the Germans reoccupied the Rhineland in March 1935. The prompted an urgent demand for rearmament and the ZM was immediately put into production with 300 being ordered initially.
Became standard infantry tank in April 1935.
Initially there was no radio in the R-35, but later models had one installed. This ended up just being a further burden on the already overworked tank commander.
The engine was to the right in the rear with the self sealing fuel tank on the left. There was a fire proof partition between the engine and fighting compartment.
The side plates carried bogies and front driving sprocket.
Steering levers controlled the brake bands in the differential and the epicyclic gears. The final drive and differentials were housed under nose plates. The engine compartment had two access door and carried the idler wheels. It was steered through a Cletrac geared differential and brakes. The turret had a domed cupola with vision slits and had to be hand cranked.
Some were fitted with tails to help in trench crossing.
Three cast sections that were bolted together. The turret was also made of cast construction.
Early vehicles were fitted with the L. 713 (APX-R) turret mounting the 37 mm Sa18 gun. Next the L.739 turret with 37 mm Sa18 M37 gun. Last production vehicles had the L.767 turret with the long barrel 37 mm Sa38. The machine guns spent shells went down a chute through a hole in the floor. The 37 mm AP round weighed 1.1 lb, and went 1,273'/sec.
The driver was located on the left and the engine and transmission on the right. The driver also had 2 visor doors. The commander had to stand on the floor of the main compartment. The commander did have a seat that rotated with the turret. There was a hatch in the rear of the turret that opened down and could be used as a seat.