Length: 20 feet 11 inches
Width: 8 feet 1 inch
Height: 9 feet 2 inches
Weight: 34 tons
Crew: Four
Armament: One 75 mm SA35 ABS howitzer (74 rounds); one 47 mm SA35 L/32 gun (62–72 rounds); two 7.5 mm Châtellerault M1931 machine guns
Armor: Front and turret, 60 mm; sides, 55 mm
Power: Renault inline six-cylinder, 16.5-liter engine (307 hp)
Suspension: Bogies with a mix of vertical coil and leaf springs
Maximum speed (road): 17 mph
Range: 112 miles
After World War I France continued development of its proven light and heavy tanks to serve as armored cavalry and infantry support, but in 1920 it also began conceiving a battle tank with the armament, armor and mobility to engage the enemy independently. The revolutionary weapon underwent protracted development before finally entering service in 1936 as the Char B1, with an armor-piercing 47 mm cannon mounted in a one-man turret and a 75 mm howitzer in the hull. As the B1’s 40 mm armor proved inadequate against Germany’s 37 mm Pak 36 anti-tank gun, designers thickened the armor to 60 mm in the Char B1 bis. They also fitted the new variant with a second carburetor to raise the horsepower from 272 to 307, though the increased weight reduced its range and running time. By the time of the German invasion of the Low Countries and France in May 1940, Renault and associated manufacturers had delivered nearly 400 Char B1 bis heavy tanks to eight battalions, including those attached to Colonel Charles de Gaulle’s 4th Armored Division.
Although the most powerful tank of its day, the Char B1 bis had been designed around an obsolete tactical doctrine. The layout put extraordinary responsibilities on two of its four-man crew—the commander also having to load, aim and fire the 47 mm turret gun, the driver having to deliberately steer the tank to line up and fire the fixed 75 mm cannon. (The Char B1 ter variant, with improved armor and limited traverse for the 75, was in the prototype stage when the German offensive began.) The Char B1 bis also suffered disproportionately from mechanical breakdowns, which accounted for more than half its losses. Nothing, however, could slow the German juggernaut. MH