Char B1 bis

Char B1 bis
Alf van Beem · Public domain · source
Name	Char B1 bis
Type	Heavy tank
Origin	France
Used by	France
Manufacturer	Renault (automobile)
Produced	1935–1940
Number	369
Weight	32 tonnes
Length	6.3 m
Width	2.5 m
Height	2.94 m
Armor	40–60 mm
Primary armament	75 mm Schneider hull howitzer
Secondary armament	47 mm SA 34 turret gun, 7.5 mm machine guns
Engine	Hispano-Suiza petrol
Speed	28 km/h

Char B1 bis The Char B1 bis was a French heavy infantry tank developed in the interwar period and fielded during the early stages of World War II. It combined a hull-mounted 75 mm howitzer with a turret-mounted 47 mm gun and heavy armor, reflecting French doctrines influenced by experiences of World War I and debates within the Commission de Vincennes and Direction des Études et Fabrications d'Armement. The vehicle saw prominent action in the Battle of France and has been examined in studies alongside vehicles such as the Panzerkampfwagen IV, Char B1, Somua S35 and Renault FT.

Design and development

The B1 bis evolved from the experimental Char B1 program initiated by the Renault design bureau under engineers who worked with industrialists like Louis Renault and organizations such as the Ministère de la Guerre and the Commission d'Etudes Techniques de l'Armement. Influenced by interwar debates that involved figures from the État-Major and doctrines advocated by officers associated with the Centre des Hautes Études Militaires, the design emphasized a combination of heavy frontal armor and a mixed armament suite to assault fortifications exemplified by experiences at the Verdun Memorial and lessons drawn from the Battle of Caporetto analyses. Trials contrasted the B1 family against contemporaries like Char D1, Char 2C, FT 17, and export considerations compared it with foreign models such as the Vickers A1E1 Independent and British Matilda II, prompting revisions to armor, suspension and powerplant undertaken at facilities including the Atelier de Construction de Rueil and Atelier de Construction de Puteaux.

Description and technical specifications

The B1 bis featured a welded and riveted hull with armor up to 60 mm, a weight of about 32 tonnes, and a four-man crew comprising a commander, gunner, driver and co-driver. Propulsion came from a Hispano-Suiza petrol engine driving a manual transmission with a top speed near 28 km/h; the suspension used vertical springs and bogies developed in cooperation with technicians who had worked on Renault UE carriers and Somua S35 running gear. Its main armament was a 75 mm Schneider hull howitzer in a centrally mounted casemate and a rotating turret armed with a 47 mm gun using ammunition types similar to those employed by SA 34-equipped tanks and Hotchkiss H35 variants; machine guns provided anti-infantry defense with barrel arrangements resembling those on vehicles produced by Hotchkiss and FAMH. Optics and communications included periscopes and radio sets supplied by firms like SETA and Thomson-Houston, reflecting procurement channels also used by Armée de Terre armored units and mechanized divisions formed by commands such as the 2e Division Cuirassée.

Production and service history

Production of the B1 bis occurred between 1935 and 1940 at plants managed by Renault and subcontractors including FAMH and state arsenals; total numbers reached approximately 369 units, many allocated to heavy tank battalions (bataillons de chars de combat) such as the BCC formations and elements integrated into organic structures of the Char Division concept promoted by proponents like Colonel Jean Estienne. Units equipped with the B1 bis were deployed in sectors including the Meuse, Somme, and Moselle during the Phoney War and the German offensive of May 1940. Following the Armistice of 22 June 1940, surviving vehicles were captured and evaluated by Wehrmacht technical services and some were pressed into service with units in theaters like Operation Barbarossa as training or second-line vehicles; captured examples were studied alongside captured Renault R35 and Hotchkiss H39 tanks.

Combat performance and operational use

In combat the B1 bis combined heavy protection and significant firepower for its era, enabling attacks on fortified positions and counterattacks against early-war Panzer units such as those fielding the Panzer I, Panzer II and early Panzer III models. Crews reported that the hull 75 mm howitzer was effective against fortifications and light armor, while the turret 47 mm could engage enemy tanks with varying success depending on range and angle of impact; battlefield accounts from engagements at places like Stonne, Hannut, and Le Cateau highlight both the vehicle's strengths and vulnerabilities. Operational limitations included slow speed, limited strategic mobility compared with armes motorisées such as the Division Légère Mécanique, high fuel consumption from the Hispano-Suiza engine, and maintenance challenges in field conditions exacerbated by logistics managed through units like the Service Automobile and supply chains tied to depots in Metz and Reims. German after-action reports praised the armor but noted tactical issues echoed in analyses by historians comparing French doctrine to German concepts exemplified by Blitzkrieg operations under commanders such as Heinz Guderian and staff decisions influenced by the Oberkommando des Heeres.

Variants and modifications

The B1 program produced several iterations and proposed conversions including experimental command variants, flamethrower-equipped proposals, and versions intended for colonial service; these were discussed in design offices alongside projects like the Char G1 and adaptations of vehicles such as the Renault FT. Modifications applied in the field and workshops included upgraded radios from suppliers such as SFR and ERB, reinforced tracks and sprockets influenced by parts used on Somua S35, and German field conversions that changed armament or removed equipment for training roles within formations like the Panzer Replacement and Training Units. Post-capture use by the Heer and examination by manufacturers including Krupp and Rheinmetall produced technical reports that informed later armored research during the Second World War.

Category:Interwar tanks Category:World War II tanks of France Category:Renault vehicles