Char B1 bis: France’s Heavily Armoured Battle Tank

The Char B1 bis was the most powerful tank in the French Army in 1940 and one of the most heavily armoured tanks in service anywhere at the start of the Second World War. Developed in the 1930s as a battle tank able to break through fortified defences and support infantry, it combined two guns in a single vehicle: a 47 mm gun in a small one-man turret and a 75 mm howitzer mounted in the hull. Its frontal armour, up to 60 mm thick, was proof against almost every German anti-tank gun in service in May 1940, and in close combat individual Char B1 bis tanks achieved remarkable results, most famously at Stonne, where a single tank disabled thirteen German tanks in one engagement.

The Char B1 bis was the production version of the Char B1, itself the outcome of a long French programme that began in the 1920s to build a heavy breakthrough tank. Production was slow and expensive, and only about 369 B1 bis tanks were completed before the fall of France, alongside 34 original B1 tanks. They equipped the armoured divisions of the French Army, the Divisions Cuirassees, and fought in the Battle of France in May and June 1940. Although the campaign ended in defeat, the Char B1 bis earned a reputation for toughness and firepower that outlived the fall of France. Captured examples were taken into German service, and the design influenced French thinking about tank construction long after the war.

Today the Char B1 bis is remembered as a symbol of French armoured power in 1940: a technically impressive tank let down by doctrine, communications, and numbers rather than by its own armour or guns. Its one-man turret, slow speed, and high fuel consumption were real weaknesses, and its crews fought in a campaign already lost at the strategic level. Yet at the tactical level the Char B1 bis was a formidable opponent, and its story illustrates how a good tank can still be defeated when it is used in small groups, without air support, and without the radio communications that its enemies enjoyed. Surviving examples in France preserve the memory of a vehicle that was, for a few weeks in 1940, the strongest tank on the battlefield in Western Europe.

1. Key Facts

Field	Value
Type	Heavy battle tank
Origin	France
Designed	1920s–1930s (Char B programme)
In service	1937–1940 (France); 1940–1945 (German captured use)
Produced	Approximately 369 B1 bis (plus 34 Char B1)
Manufacturers	Renault, FCM, AMX, Schneider, Fives-Lille
Crew	4 (commander/gunner, driver, loader/radio operator, hull gunner)
Weight	Approximately 32 tons
Length	Approximately 6.52 m (21 ft 5 in)
Width	Approximately 2.50 m (8 ft 2 in)
Height	Approximately 2.79 m (9 ft 2 in)
Armour	Up to 60 mm frontal
Main armament	47 mm SA 35 gun in turret; 75 mm ABS SA 35 howitzer in hull
Secondary armament	Two 7.5 mm Reibel machine guns (one coaxial, one in hull)
Engine	Renault six-cylinder petrol engine, approximately 307 hp
Speed	Approximately 28 km/h (17 mph) maximum on roads
Range	Approximately 180 km (112 miles) on roads

2. Background and Development

The French Battle Tank Programme

The Char B1 bis grew out of a French Army programme that began in the early 1920s, when French planners sought a heavy tank able to break through fortified lines of the kind they had faced in the First World War. The specification called for a vehicle that could cross trenches, climb obstacles, and destroy enemy strongpoints with a hull-mounted howitzer, while a smaller turret gun dealt with enemy tanks. Several firms contributed designs, and the resulting Char B went through a long series of prototypes, known as the SRA, SRB, and SRC vehicles, before a production design was settled. The process was slow because French industry was still recovering from the war, and because the specification changed repeatedly as the army debated the role of the new tank.

From Char B1 to Char B1 bis

The original Char B1 entered production in the mid-1930s, but only 34 were built before production shifted to the improved B1 bis version. The B1 bis received thicker armour, up to 60 mm, a more powerful Renault engine, and a new turret, the APX4, mounting the long 47 mm SA 35 gun, which was a far more effective anti-tank weapon than the short 47 mm gun of the B1. The hull howitzer remained the 75 mm ABS gun, aimed by the driver through a telescopic sight, while the commander, alone in the turret, had to command the tank, aim and fire the turret gun, and load it. Production was shared between several firms, with Renault as the lead contractor, and the work was slow because the tank was complex and expensive. By May 1940 about 369 B1 bis tanks had been delivered, a number far below the original plan.

Doctrine and the Divisions Cuirassees

French doctrine assigned the Char B1 bis to the Divisions Cuirassees, the armoured divisions intended to form the mobile reserve of the French Army and to counter-attack any German breakthrough. In theory these divisions, with their heavy tanks and supporting infantry and artillery, were powerful formations. In practice they were hampered by poor communications, because most French tanks had no radio or only a receiver, by a shortage of fuel transport, and by the fact that the divisions were still forming when the German attack came. The Char B1 bis was also intended to work closely with infantry, and its slow speed was accepted because it was meant to advance at the pace of a deliberate breakthrough. The French Army thus had a strong tank but a doctrine that used it cautiously, in small packets, rather than in the massed armoured thrusts that the Germans practised.

3. Design

Hull, Tracks and Mobility

The Char B1 bis had a long, tall hull with a distinctive track layout that wrapped around the vehicle, with the drive sprocket at the front and the idler at the rear. The design gave the tank good trench-crossing ability, and it could climb a vertical obstacle of about 0.90 m and cross a trench about 2.75 m wide. The suspension used vertical coil springs, and the tank rode steadily, although its top speed of about 28 km/h was slow by the standards of 1940. The Renault six-cylinder petrol engine, producing about 307 horsepower, was adequate but left little power in reserve for a 32-ton vehicle, and fuel consumption was high. The tank carried about 400 litres of fuel, giving a road range of about 180 km, but cross-country the range fell sharply, and the Char B1 bis often needed refuelling during operations.

Armour and Protection

The armour of the Char B1 bis was its greatest strength. The hull and turret were protected by up to 60 mm of armour plate, a figure unmatched by any German tank in 1940 and thicker than the armour of most Allied tanks. The front of the hull and the turret were the most heavily protected, while the sides and rear were thinner but still substantial. The armour was bolted and riveted in places, and the hull was built up from plates, a construction method that was already old-fashioned by 1940. Even so, the protection proved effective in combat: German 37 mm anti-tank guns, the standard German anti-tank weapon in 1940, could not penetrate the Char B1 bis at normal ranges, and German tank guns, the short 75 mm of the Panzer IV and the 37 mm of the Panzer III, were also unable to defeat its frontal armour. Only the German 88 mm gun, used in the anti-aircraft role, and close-range hits from heavier guns could reliably destroy it.

The One-Man Turret Problem

The most serious design weakness of the Char B1 bis was its one-man turret. The commander had to command the vehicle, observe the battlefield, aim and fire the 47 mm gun, and load it, all at the same time, while the hull gunner operated the 75 mm howitzer under the direction of the driver. In combat this workload was overwhelming, and the rate of fire of the turret gun was low. The commander also had poor visibility from the small turret, and the tank had no cupola of the kind that later tanks used. The French Army was aware of the problem, and later designs moved towards two- and three-man turrets, but the B1 bis went to war with the one-man turret intact. The flaw did not prevent individual tanks from fighting well, but it reduced the effectiveness of the type as a whole, especially in fast-moving engagements where the commander had to react quickly to new threats.

Armament and Crew

The armament of the Char B1 bis was unusual and powerful. The turret mounted the 47 mm SA 35 gun, a capable anti-tank weapon that could penetrate the armour of any German tank in 1940. The hull mounted a 75 mm ABS howitzer, fired by the driver, which was intended to destroy fortifications, machine-gun nests, and anti-tank guns with high-explosive shells. Two 7.5 mm Reibel machine guns provided close defence, one coaxial with the turret gun and one in the hull. The crew of four was divided between the turret, where the commander worked alone, and the hull, where the driver, the loader and radio operator, and the hull gunner worked in cramped conditions. Communication inside the tank was by voice tube and by hand signals, and the lack of an intercom made coordination difficult. The division of labour between the hull howitzer and the turret gun was a legacy of the First World War, and it worked best in a deliberate assault against fixed defences.

4. Variants

Char B1 and Char B1 bis

The two production versions of the Char B were the original B1, of which 34 were built, and the B1 bis, of which about 369 were built. The B1 had thinner armour, a less powerful engine, and a short 47 mm gun in its APX1 turret, while the B1 bis had 60 mm armour, a 307 horsepower engine, and the long 47 mm SA 35 gun in the APX4 turret. The B1 bis also had a different radio fit and minor improvements to the hull. The two types served side by side in 1940, and the B1 was already regarded as obsolescent when the war began. A further development, the Char B1 ter, with a larger turret and a more powerful engine, was under development in 1940 and a small number of hulls were built, but none entered service before the fall of France.

Captured Vehicles in German Service

After the fall of France, the Germans captured a large number of Char B1 bis tanks, many in running order, and took them into service as the Panzerkampfwagen B2 740(f). German units used them for occupation duties, for training, and, in some cases, in combat. Some were converted into flamethrower tanks, the Flammpanzer B2, with a flame projector replacing the hull howitzer, and others were converted into self-propelled guns or training vehicles. A number were used on the Channel Islands and in France, and a few were still in German service in 1944. The German reuse of the Char B1 bis was a measure of its quality: the Germans had little use for captured tanks that were unreliable or weakly armed, but the B1 bis was worth keeping, even though its one-man turret and slow speed limited its usefulness in German service as well.

The B1 ter and Unbuilt Developments

The Char B1 ter was the final development of the Char B line, intended to correct the weaknesses of the B1 bis. It had a larger, two-man turret, a more powerful engine, and a modified hull, and five were under construction in 1940. None was completed in time to see service, and the design was abandoned after the armistice. French designers also studied a Char B with a larger gun and a redesigned turret, but the fall of France ended the programme. The B1 ter remains a reminder that French tank design was evolving, and that the B1 bis, for all its flaws, was not the end of the line but a stage in a longer development that the war cut short.

5. Operational History

The Battle of France

Char B1 bis tanks fought throughout the Battle of France, from the German attack on 10 May 1940 to the armistice on 22 June. They served in the 1st, 2nd, 3rd, and 4th Divisions Cuirassees, and in independent tank battalions. The divisions were committed piecemeal to counter-attack German breakthroughs, and they often fought without adequate infantry, artillery, or air support. Even so, the Char B1 bis proved a formidable opponent. German tank crews reported with alarm that their guns could not penetrate its armour, and German anti-tank gunners found their 37 mm guns useless against it. French losses were heavy, but they were caused more by mechanical breakdown, lack of fuel, and air attack than by German tanks. Many Char B1 bis tanks were abandoned for lack of fuel or after running out of ammunition, and their crews often destroyed them to prevent capture.

Stonne and Captain Billotte

The most famous action involving the Char B1 bis took place at Stonne, a village on the road to Sedan, on 16 May 1940. Captain Pierre Billotte, commanding a Char B1 bis named Eure, advanced into the village and engaged a column of German tanks. In the course of the action his tank destroyed thirteen German tanks, two anti-tank guns, and a number of other vehicles, while receiving about 140 hits without being penetrated. The action at Stonne became a legend in French military history, and it demonstrated what the Char B1 bis could achieve when it was used aggressively and at close range. Stonne itself changed hands many times in the following days, and the village was largely destroyed, but the action of Billotte’s tank remains the best-known single-tank action of the 1940 campaign. Other Char B1 bis crews also fought with distinction, and the tank’s reputation for invulnerability in 1940 was based on such actions.

Losses and the Fall of France

Despite the individual successes, the Char B1 bis could not change the outcome of the campaign. The French armoured divisions were committed too late and in too small numbers, and the German advance through the Ardennes outflanked them. Many Char B1 bis tanks were lost to Stuka dive-bombers, to artillery, and to mechanical failure, and many more were abandoned when their units ran out of fuel. By the time of the armistice, most of the Char B1 bis tanks had been destroyed or captured. The survivors were taken into German service, and the French Army did not use the type again. The loss of the Char B1 bis was not the cause of the French defeat, which was a failure of strategy and command, but it was a symbol of it: a good tank, used badly, in a campaign already lost.

6. Performance and Specifications

Strengths on the Battlefield

The strengths of the Char B1 bis were its armour and its firepower. No German tank or anti-tank gun in general service in 1940 could penetrate its frontal armour, and its 47 mm gun could destroy any German tank it met. The 75 mm hull howitzer gave it a useful high-explosive capability against soft targets, and its trench-crossing ability was good. Crews who fought in the Char B1 bis generally had confidence in its protection, and German accounts of the 1940 campaign repeatedly mention the shock of meeting a tank that their guns could not stop. In a defensive role, or in a deliberate assault against a fixed position, the Char B1 bis was a formidable weapon, and its performance at Stonne showed what it could do when it was well handled.

Weaknesses and Trade-offs

The weaknesses were equally clear. The one-man turret imposed an impossible workload on the commander and reduced the rate of fire. The top speed of about 28 km/h was slow, and the fuel consumption was high, giving the tank a short operational range and a heavy logistical burden. The lack of radios in many tanks made coordination difficult, and the internal communications were poor. The hull howitzer, aimed by the driver, was difficult to use against a moving target, and the division of the armament between two crew members was a complication that later tank designs abandoned. The Char B1 bis was also expensive and slow to build, and the French Army never had enough of them. These weaknesses did not make it a bad tank, but they limited its effectiveness, especially in the mobile warfare of 1940.

How the Char B1 bis Compared with Rivals

Compared with the German Panzer III and Panzer IV of 1940, the Char B1 bis was more heavily armoured and more heavily armed, but slower and more difficult to command. Compared with the British Matilda II, another heavily armoured infantry tank, it was similarly well protected but had a more powerful armament and a higher speed. Compared with the Soviet T-34, which entered service a year later, the Char B1 bis was slower, less well designed for mass production, and hampered by its one-man turret, although its armour was comparable. The Char B1 bis was thus a strong tank by the standards of 1940, but its design belonged to an earlier generation, and the tanks that followed it, with two- and three-man turrets and better communications, were more effective as a whole.

7. Comparison

Against German Tanks of 1940

In a direct comparison with the German tanks it faced in 1940, the Char B1 bis held a clear advantage in armour and firepower. The Panzer III, the main German battle tank, carried a 37 mm gun that could not penetrate the Char B1 bis at normal combat ranges, while the 47 mm gun of the Char B1 bis could penetrate the Panzer III with ease. The Panzer IV, with its short 75 mm gun, was intended for infantry support and was also unable to defeat the Char B1 bis frontally. German tank crews therefore avoided direct engagements with the Char B1 bis when they could, and relied on anti-tank guns, artillery, and air attack to deal with it. The German advantage lay not in the tank itself but in the way it was used: German tanks had radios, three-man turrets, and a doctrine of massed, coordinated attack, while French tanks often fought alone and without support.

Against Other Allied Heavy Tanks

Among Allied tanks, the closest comparison is with the British Matilda II, which also entered service in 1940 with very thick armour and a two-pounder gun. The Matilda II was slower than the Char B1 bis and had a smaller gun, but it had a two-man turret and was mechanically simpler. The Char B1 bis had the better armament, with its 47 mm and 75 mm guns, but the Matilda II was easier to command and to maintain. Both tanks were designed for the same role, the deliberate breakthrough against a fortified defence, and both were overtaken by the demands of mobile warfare. The Char B1 bis was the more powerful of the two, but the Matilda II was the more practical, and the comparison illustrates the trade-off between firepower and usability that ran through tank design in the early war.

8. Legacy and Influence

The End of the French Battle Tank

The Char B1 bis was the last of the French battle tanks of the interwar period, and its fate was bound up with the fall of France. After the war, French tank design moved in a different direction, towards lighter, faster tanks with larger turrets and better communications, and the lessons of the Char B1 bis were absorbed into the post-war AMX designs. The type itself was not revived, and the surviving vehicles became museum pieces rather than the basis for a new generation. The Char B1 bis remains, however, a landmark in French tank design: the most ambitious French tank of the 1930s, and the strongest tank in service in Western Europe in May 1940.

Reputation and Historical Assessment

Historians have reassessed the Char B1 bis in recent decades, moving away from the view that French tanks in 1940 were simply inferior to German tanks. The evidence of Stonne and other actions shows that the Char B1 bis was a formidable vehicle, and that the French defeat was a failure of doctrine and command rather than of equipment. The tank’s reputation has also been helped by the survival of detailed accounts from its crews, and by the work of historians who have studied the French armoured divisions in detail. The Char B1 bis is now generally regarded as one of the best tanks of 1940, and as a vehicle whose design flaws were real but whose combat performance, when it was well handled, was outstanding.

Lessons for Later Tank Design

The lessons of the Char B1 bis were clear to post-war designers. The one-man turret was abandoned, and all later French tanks used two- or three-man turrets. Radios became standard in every tank, and internal communications were improved. The idea of a hull-mounted howitzer, aimed by the driver, was also abandoned, and the main gun was concentrated in the turret. The emphasis on thick armour, however, was retained, and the post-war French AMX-50 and other designs continued to value protection. The Char B1 bis thus contributed to tank design not by being copied but by showing what did not work, and by demonstrating that armour and firepower alone are not enough without good communications and a workable crew layout.

9. Surviving Examples

Museums in France

A number of Char B1 bis tanks survive in museums in France. The most famous is the Char B1 bis at the Musee des Blindes at Saumur, which preserves an example in running condition and displays it at public events. The Saumur vehicle is one of the best-known surviving French tanks, and it is regularly seen at the museum’s annual open days. Other examples are held at the Musee de l’Armee in Paris and at regimental museums, and a small number are in private collections. The survival of these vehicles is remarkable given the small production run and the heavy losses of 1940, and they are an important part of the French military heritage.

Survivors Abroad

Other Char B1 bis tanks survive outside France, including examples in Britain and in other countries that received captured vehicles. The Tank Museum at Bovington in Britain holds a Char B1 bis, which is displayed as an example of the French tank that German crews found so difficult to defeat in 1940. A small number of hulls and wrecks have also been recovered from battlefields in France, and some have been restored. The surviving Char B1 bis tanks are valued not only as museum exhibits but as evidence of the quality of French tank construction in the 1930s, and they continue to attract attention from historians and enthusiasts who study the Battle of France.

10. Frequently Asked Questions

How many Char B1 bis tanks were built?
About 369 Char B1 bis tanks were built, plus 34 original Char B1 tanks. Production was slow and expensive, and the French Army never received as many as it had planned before the German attack in May 1940.

Why did the Char B1 bis have two guns?
The tank was designed as a breakthrough vehicle. The 75 mm howitzer in the hull was meant to destroy fortifications and machine-gun positions, while the 47 mm gun in the turret was meant to deal with enemy tanks. The arrangement was a legacy of First World War thinking.

Was the Char B1 bis proof against German guns in 1940?
Its frontal armour, up to 60 mm thick, was proof against the German 37 mm anti-tank gun and the guns of the Panzer III and Panzer IV at normal ranges. Only the 88 mm gun and close-range hits from heavier weapons could reliably penetrate it.

What happened at Stonne?
On 16 May 1940 Captain Pierre Billotte, in a Char B1 bis named Eure, destroyed thirteen German tanks and two anti-tank guns in a single action at Stonne, while his own tank received about 140 hits without being penetrated. It remains the most famous Char B1 bis action.

What happened to captured Char B1 bis tanks?
The Germans took captured Char B1 bis tanks into service as the Panzerkampfwagen B2 740(f). Some were converted into flamethrower tanks, and others were used for training and occupation duties. A few were still in German service in 1944.

Why did the Char B1 bis not save France in 1940?
The tank was strong, but it was used in small numbers, without radios, without air support, and under a doctrine that committed armoured divisions piecemeal. The French defeat was a failure of strategy and command, not of the tank itself.

11. Sources

• Steven J. Zaloga, French Tanks of World War II (Osprey Publishing, New Vanguard series).
• Pierre Touzin, Les blindes francais 1940 (Histoire et Collections).
• The Musee des Blindes, Saumur, Char B1 bis collection records and vehicle guides.
• Chamberlain, Peter, and Ellis, Chris, British and American Tanks of World War II (Arms and Armour Press).
• Francois Vauvillier, The Encyclopaedia of French Tanks and Armoured Fighting Vehicles 1914-1940.
• British War Office, Handbook on the French Army (wartime intelligence publication).