Char D1

Char D1
D1 with ST2 turret in 1936
Type	Medium tank
Place of origin	France
Service history
In service	1932 - 1943
Production history
No. built	160
Specifications
Weight	14 metric tons
Length	5.76 m
Width	2.16 m
Height	2.40 m
Crew	3
Armor	40 mm
Main armament	47 mm SA34 tank gun
Secondary armament	2x 7.5 mm Reibel machine gun
Engine	Renault V-4 74 hp
Suspension	vertical springs
Operational range	90 km
Speed	18.6 km/h (11.6 mph)

The Char D1 was a pre-World War II French medium tank.

The French plan of 1926, calling for the creation of a Light Infantry Support Tank, led to the development of the existing Renault NC1 prototype into the Char D1. One hundred and sixty vehicles of this type were produced between 1931 and 1935. There was a pre-series of ten vehicles and later 150 standard vehicles were built. Until 1936 the vehicles were fitted with Renault FT turrets because the intended cast ST2 turrets were not yet ready. The ST2 turret was armed with a short 47mm SA34 tank gun with a coaxial 7.5mm machine gun. The hull carried a 7.5mm MG in the bow. The type did not serve as an infantry support tank as originally intended, but as France's major battle tank of the early thirties; it was quickly phased out in 1937 because of its mechanical unreliability and relegated to colonial units in North Africa.

After World War I, France possessed a very large fleet of Renault FT light infantry support tanks. Although many of these were sold to other nations, over 2800 remained. In contrast to the United Kingdom, which greatly reduced its armoured forces and scrapped redundant AFVs after the war, France maintained a large number of active or reserve armoured units (with an organic tank strength of about 1260) and all of the remaining Renault FTs were kept in working order. This implied that in the early twenties France had the strongest and most modern armoured force in the world, but this very fact led to a state of complacency. Development of new tank models was not seen as urgent, and budgetary restraints would for the immediate future prohibit any further tank production. When in 1922 General Jean Baptiste Eugène Estienne concluded an official study containing guidelines for long term tank design, no provisions were made for any new light infantry tank.

The remaining Renault FT vehicles, though having shown themselves to be very effective in trench warfare, were not well adapted in their present state of technological development to peacetime conditions. The main problem was their low top speed, which necessitated special tank transporters whenever the vehicles had to be moved outside their base area and made them fundamentally unsuited to patrolling duty in the colonies. It was therefore decided to modify a number of existing vehicles, by fitting them with a more effective suspension system. The first modifications were of the Renault FT Kégresse-type, which featured the suspension of the Kégresse half-track, fitted with a special rubber steel-reinforced track. In 1925 42 vehicles were rebuilt this way and deployed in 1926 during the Berber insurrection in Morocco. The modification allowed for a top speed of 17 km/h but field experience showed that the track was liable to suddenly snapping at top speed with often catastrophic consequences and the modification project was therefore discontinued. Nine Renault FT Kégresse vehicles were later sold to Yugoslavia and five to Poland.