Char B1

Char B1
The Char B1 bis Rhône at the Musée des Blindés at Saumur
Type	Medium tank
Place of origin	France
Service history
In service	1936–1940 (France) 1944–1945 (Free French Forces)
Used by	France, Germany
Wars	Second World War
Production history
Designed	1921–1934
Manufacturer	Renault and others
Produced	1935–1937 (Char B1) 1937–1940 (Char B1 bis)
No. built	405 (34 Char B1, 369 Char B1 bis & two Char B1 ter)
Specifications
Weight	28 tonnes
Length	6.37 m (20 ft 11 in)
Width	2.46 m (8 ft 1 in)
Height	2.79 m (9 ft 2 in)
Crew	4
Armor	40 mm (Char B1) 60 mm (Char B1 bis)
Main armament	75 mm ABS SA 35 howitzer
Secondary armament	47 mm SA 34 (Char B1) 47 mm SA 35 (Char B1 bis) 2 × 7.5 mm Reibel machine guns
Engine	Renault inline 6 cylinder 16.5 litre petrol 272 hp
Power/weight	9.7 hp/tonne
Transmission	5 forward, 1 reverse gear
Suspension	bogies with a mixture of vertical coil and leaf springs
Fuel capacity	400 L
Operational range	200 km (120 mi)
Speed	28 km/h (17 mph) 21 km/h (13 mph) off-road
Steering system	double differential

The Char B1 was a French medium tank manufactured before World War II.

The Char B1 was a specialised break-through vehicle, originally conceived as a self-propelled gun with a 75 mm howitzer in the hull; later a 47 mm gun in a turret was added, to allow it to function also as a Char de Bataille, a "battle tank" fighting enemy armour, equipping the armoured divisions of the Infantry Arm. Starting in the early twenties, its development and production were repeatedly delayed, resulting in a vehicle that was both technologically complex and expensive, and already obsolescent when real mass-production of a derived version, the Char B1 "bis", started in the late thirties. Although a second uparmoured version, the Char B1 "ter", was developed, only two prototypes were built.

Among the most powerfully armed and armoured tanks of its day, the type was very effective in direct confrontations with German armour in 1940 during the Battle of France, but slow speed and high fuel consumption made it ill-adapted to the war of movement then being fought. After the defeat of France captured Char B1 (bis) would be used by Germany, with some rebuilt as flamethrowers or mechanised artillery.

The Char B1 had its origins in the concept of a Char de Bataille conceived by General Jean Baptiste Eugène Estienne in 1919, e.g. in his memorandum Mémoire sur les missions des chars blindés en campagne. It had to be a "Battle Tank" that would be able to accomplish a breakthrough of the enemy line by destroying fortifications, gun emplacements and opposing tanks. In January 1921 a commission headed by General Edmond Buat initiated a project for such a vehicle. To limit costs, it had to be built like a self-propelled gun, with the main weapon in the hull. To minimise the vehicle size this gun should only be able to move up and down with the horizontal aiming to be provided by turning the entire vehicle. The specifications included: a maximum weight of thirteen metric tonnes; a maximum armour thickness of 25 millimetres; a hull as low as possible to enable the gun to fire into the vision slits of bunkers; a small machine gun turret to beat off enemy infantry attacks, at the same time serving as an observation post for the commander and a crew of at most three men. Two versions should be built, one a close support tank armed with a 75 mm howitzer, the other an antitank-vehicle with a 47 mm gun instead.