Status Report: 1935-1936 BatChat, APX and FCM designs
The last time we left off, it was 1934 and the French military was looking for a new infantry light tank. From 14 companies originally submitting their proposals only 7 were left and on 22.5.1934, the military changed its demands as follows:
- armor was to be improved from 30mm to 40mm
- maximum speed was to be 15-20 km/h
- vehicle was to be equipped with a 37mm gun
In the end, only 4 companies remained - these got the production of their prototypes paid by the states. The companies were: Delaunay Belleville, Compagnie Générale de Construction de Locomotives (Batignolles-Châtillon), Forges et Chantiers de la Méditerranée (FCM) and Renault.
There was also the Hotchkiss company, which in fact initiated the entire program of 1933 - the Hotchkiss prototype was built as well, but it left the "infantry" light tank category and moved on to the "cavalry support" category competition, that ran in parallel with the infantry one. It was actually a turretless vehicle with a machine-gun in the hull.
The army wasn't exactly interested in it, but it served as a good demonstrator of the new technologies, allowing Hotchkiss to develop what would become the second most mass-produced French light tank, the Hotchkiss H35.
But back to the infantry competition. Delaunay Belleville was one of the least known armor designers - in fact, the company (based in St.Denis) designed luxury cars before the war. Even they however wanted a piece of the army budget pie and presented their own light tank prototype as well - unfortunately, no drawings or photographs survived.
The last party that should be mentioned was Batignolles-Châtillon - they too made a light tank prototype, but its fate was quite different. The Batignolles-Châtillon company back then was a well-known steam locomotive producer from Nantes and even they got into the business of building tanks, creating one prototype in 1935. In April 1935, they submitted the vehicle for military trials.
All the while their competition was using welded or cast hulls and turrets, the Batignolles-Châtillon prototype - designated simply "six ton tank" (Char 6t) - was riveted, since rivets were used in locomotive building and therefore they were readily available. The turret was cast however and somewhat resembled the design the FCM company came up with for their own prototype. In fact, the vehicle itself resembled the FCM prototype (that would later become FCM 36). Among the advantages of the BatChat design was the excellent visibility - the commander could see very well outside through a number of slits and the reasonably-shaped hull, offering solid protection. The suspension consisted of six road-wheels, paired into three bogies with horizontal springs was actually a quite good design as well. All in all, in theory it was a pretty good vehicle, it certainly wasn't considerably worse than its competitors. However, its reliability became its downfall and the vehicle had to be returned to the factory for repairs very early on. The repairs and improvements were ready in the summer of 1936 but by that time the FCM company already successfully marketed their FCM 36 tank for mass-production and second such vehicle was not needed.
Apart from these four companies (plus Hotchkiss), there was one more company that attempted to propose a tank for the French army - it was the tank design division of the artillery-producing industry giant, Ateliers de Puteaux (APX). They proposed a tank in the 6 ton category - not only did they design it, but they also built it according to the 1933 specifications (the 30mm armor ones). It was designated Char 6 T.
The first project proposal for this tank appeared in February 1934 and the vehicle was to be made using mostly casting. It wasn't exactly huge (with the "tail" it was 4,4m long, 1,58m wide and 1,85m tall) and was to be powered by a 65hp 2-stroke diesel. With its weight of 6,85 tons, it was more than sufficient to support infantry (power-to-weight ratio was 9,5 hp/t). The suspension consisted of 11 road-wheels, giving the vehicle a lot of contact space with ground and potentially making the ride very smooth - it was supposed to be protected by armor plates. Overall, the tank armor was 30mm thick on all sides.
The armament was based on the 1933 specifications and therefore it was proposed in two variants: either a 37mm SA18 gun with a coaxial 7,5mm MAC Mle.1931 machine-gun, or a pair of the same machine-guns. The armament was initially installed in a one man turret which was - to put it mildly - very small. However, as early as on 18.2.1934, the APX designers introduced a new turret, designated APX R. Unfortunately, no pictures of the APX 6 T survived either. According to the info available, the prototype was built in October 1935 but by that time, there was no more need for yet another light tank, especially if the company was not among the "chosen ones" - the prototype was probably scrapped later on. There was one part of it however that was very successful - the turret. In fact, the APX R turret was so good that it was selected as a standard turret for Renault R35 and Hotchkiss H35 and in this sense, APX was at least partially successful. The tank failed, but the turret contract turned out to be quite lucrative nonetheless.
As for the last of the "big three", FCM - they built what would become one of the more successful and mass-produced French light tanks, the FCM 36. It was actually quite advanced - as first tank in the world, it used three major features in one vehicle: diesel engine, light anti-shell plates and sloped armor. Apart from all that, it was also completely welded. In total, the FCM design did fit the French military specs the best. There were two major drawbacks to it - the vehicle was heavy (12,35 tons) and it was expensive: 450 thousand Francs per vehicle (for comparison, Hotchkiss H35's cost was 200 thousand). This steep price resulted in only 100 being built, despite its undeniable qualities.
It's worth noting that FCM continued to work on their light tank, introducing the SA38 longer gun to its improved turret in 1938. Between 1938 and 1939, FCM managed to acquire two more contracts for building 200 vehicles, but this never went anywhere - in 1939, the FCM company production plan was changed to build the Char B1 bis heavy tank, required by the army - in total 72 out of 403 of these vehicles were built by FCM.