FCM F1 - The Char D'Attaque Des Fortifications

The Char D'Attaque Des Fortifications

The commission immediately revived the Char Lourd concept but applied it only to the "45 ton tank" project and differentiated this from a tank optimised for destroying modern fortifications, a Char d'Attaque des Fortifications. This latter vehicle should have a powerful high velocity gun in a turret but be itself immune to enemy antitank-guns. Speed was considered of secondary import and might be as low as 10 km/h maximum. However trench-crossing and wading abilities would have to be excellent. If this should result in an overly cumbersome vehicle, it should be made modular so that the components could be transported separately. On 4 May 1938 the Direction des Fabrications d’Armement proposed to call this the Char H project, to distinguish it from the Char F, but this was rejected as there was some danger of confusion with the Hotchkiss H35.

The French High Command approved the commission's plans in April 1938 and proceeded to appoint a second commission to work them out in detail. This new commission was also charged with considering the question of whether a 45 ton vehicle might not after all be sufficient. In its first meeting, on 9 May 1938, the commission quickly came to the conclusion that to meet the tactical demands a 75 mm gun in a turret and 120 mm allround armour was necessary; this could not be reconciled with a weight of 45 tons. On the other hand, a design to equal the climbing and crossing mobility of even the old Char 2C would likely result in a 150-200 ton behemoth, of which even the components of a modular design would be impractical to transport. It was therefore decided to further research the possibility of a 65 ton vehicle, with an empty hull weight of 45 tons.

In its second meeting on 22 July 1938, some troubling data were considered. Most bridges could carry a maximum single vehicle load of 35 tons, so the new tank would have to cross rivers on special pontoons. German tank moats transpired to have a width of about seven metres, so a very long vehicle seemed to be necessary. Existing rail road cars could carry a maximum of 100 tons though. It was also pointed out that 120 mm armour might not be enough in view of the powerful German 88 mm gun. The commission rejected the char minimum proposal of 56 tons as it had insufficient trench-crossing capacity. It also discarded a proposal by the engineer Boirault to build a futuristic 120 ton articulated tank. It retained two options: the char maximum of 89 tons, demountable in two sections, and the char squelette of 110 tons and with a trench-crossing ability of eight metres; this latter design was along the general lines of the World War I American Skeleton Tank, but with the added feature that the main body could move in relation to the skeleton track frame in order to shift its point of gravity.

In September 1938 the Supreme Command ordered to immediately start research by the French industry into both possibilities. The ARL company was granted a development contract for the char maximum, the first proposal for which was presented by ARL in May 1939. It had a proposed weight of 120 tons, consisted of two detachable modules and could be armed with either a gun or a flamethrower. The commission decided that only the guntank would be considered, but that a second turret at the back was needed for defence against infantry assault. It also remarked that the project was quite similar to that of the Char F1 and that perhaps both programmes should be merged.