The peace treaty between France and Germany signed on June 22nd, 1940, meant the defeat of France in WWII. The fact that France was only able to hold on against Germany for 40 days shocked many. France had the second largest tank force behind only the USSR, and it seemed impossible that this armada could not resist the German advance. However, this defeat was inevitable. The problem wasn't that French tankers, as fiercely as they fought, had little experience. The problem was in the tanks themselves.
Echoes of the past war
The French were the second nation to develop and use tanks in WWI. Despite the British head start, the French managed to build the better tanks. Instead of heavy tanks, they started with medium ones. One of them, the Saint Chamond, was the herald of a revolution. Its designer, Émile Rimailho, the chief designer at Compagnie des Forges et Acieries de la Marine et d'Homecourt (FAMH), used an electric transmission on this tank. Unlike the British, the French rapidly abandoned the "machine gun hedgehog" form factor and developed a tank with armament in a turret by 1917. The French were also the first to put a light tank into production, the famous Renault FT. This was the best tank of WWI and the most numerous one, put into production at multiple factories.
The French were also successful at heavy tank development. Even though they were only put into production after WWI ended, these vehicles were a true testament to engineering expertise. The FCM 2C was the largest and heaviest tank ever built in France (and the largest mass produced tank to this day). This was the first vehicle to receive shell-proof armour and the first to have a three-man turret with a 75 mm gun. The FCM 2C remained competitive for over a decade, which explains its long service life.
Champs-Élysées, July 14, 1919. The Renault FT became the main hero of parades like this one for more than a decade.
The success of French tank building led to its stagnation. The French army entered the 1920s with a stock of about 3500 Renault FT tanks and a few hundred obsolete medium tanks. While the medium tanks were written off fairly quickly, the Renault FT would go on to enjoy a career spanning decades. There were too many of them for the army to consider replacement any time soon. Funding cuts only made the situation worse. However, it was not the only issue. The British and Americans managed to continue experimental work even on a tight budget. The Americans failed to obtain a mass produced tank, but their work paid off in the 1930s. The British attained excellence in tank development both for their own needs and for export. Only the French focused on modernizing the Renault FT.
The Scheider-Renault SRA, a candidate for the Char B program. This was more of an assault gun than a tank. The mass exceeded the stated limit of 5 tons.
The only program that reached the prototypes stage was the "battle tank" (Char de Bataille or Char B for short). This tank was envisioned by Jean Baptiste Estienne, the father of French tank building. His ideas were revolutionary for their time, but many questions were raised in the 1920s. It became more and more clear that tanks have to be more mobile and their range had to increase. This resulted in work on convertible drive tanks, the first of which were not very successful. Nevertheless, the speed of tanks slowly grew. It first reached 20 kph, then 30-35 kph by the end of the 1920s. Meanwhile, Estienne had his own ideas. Instead of the Renault FT, he envisioned a 14.3 ton tank armed with a 75 mm gun in the hull, something similar to the Schneider CA1, but smaller and with a 3-man crew. The turret was optional and in any case would not house anything bigger than a machine gun. The first Char B prototypes were presented in 1924. These tanks had a mass of 15.5-19 tons and 25-30 mm of armour. This armour was sufficient to withstand cannon shells. Typical anti-tank armament of the time, such as the Hotchkiss 47 mm gun, penetrated up to 25 mm of armour.
General Estienne, the father of French tank building. His ideas were revolutionary at first, but later he drove French tank building into a dead end.
While Estienne tried to replace light tanks with medium ones, the Technical Tank Section (Section technique des chars de combat, STCC) developed new light tanks. They gave France the Renault NC-1 STCC, a variant of the Renault NC with a new suspension and a turret with two machine guns. Further development of the Renault FT concept resulted in the NC-3 tank, later accepted into service as the Char D1. This was essentially an enlarged Renault FT with a more powerful engine, new suspension, and 30 mm of armour. A dedicated radio operator was added in the hull. It must have been painful to watch French tank designers develop new turrets with the same dimensions as the Renault FT's. Nearly everyone considered this turret too small and tried to develop a similar one, but larger (FIAT 3000 or MS-1). The French managed to fit a 47 mm gun with a coaxial machine gun in the same turret ring. This didn't happen on the first try, and overall the Char D1 had 4 different turrets, including temporarily using the Renault FT turret.
The only success of French tank building in the 1920s: the Char D1. This tank took five years of polishing, but the result was the best among French light tanks.
As a result, the French army had no original tanks by the 1930s. What's worse, Estienne and other French generals expected the next war to be the same as WWI. Meanwhile, local conflicts showed the opposite, especially when it came to mobility and overall development of tanks. The French continued to capitalize on experience from WWI, slowly making their position worse. The situation that developed by the start of WWII had long roots. Don't blame Estienne alone, French tank development had plenty of "fathers". For instance, the CCA (Conseil Consultatif de l'Armement), which was full of questionable characters weighed down by ranks and titles. One of them was General Charles Chédeville, commander of the 2nd Tank Brigade in WWI. He was certain that the Char B had to be France's main tank and that mass produced light tanks were a thing of the past. General Paul Velpris, Inspector General of tanks, was another quite interesting character. In 1923, still a colonel, he proposed a 600 ton tank. His later publications didn't offer such monsters, but his ideas were clear. The CCA continued to draw pictures of WWI style mass advances, which made their desire for the Char B logical.
A crisis of ideas
French high command started to figure out that something was wrong in the early 1930s. Their tanks were rapidly becoming obsolete and their position of the nation with the most tanks was worth less and less. The French were lucky that there were no major conflicts in the early 1930s and that tank building worldwide was paralyzed by a financial crisis. Additionally, two disarmament conferences were held: one in London in 1930 and another in Geneva in 1932. The 1930 conference limited the weight of tanks to 25 tons and the Geneva conference went even further: to 16 tons. This limit didn't last long, but it held back one of Estienne's ideas: heavy tank destroyers. These 44-55 ton vehicles were supposed to complement the Maginot Line. Work on these vehicles began in 1928 at FCM and STCC. Work stopped in 1932, but only for a time.
The Char BB, the first iteration of a superheavy tank for reinforcing the Maginot Line.
The situation began to change in 1933 when the Nazis came to power in Germany. The only modern tank that France had at the time was the Char D1, and it did not even have a turret yet. The turret was finished only in 1936, much later than the rest of the tank. Work on an improved variant called Renault UZ (or better known as the Char D2) began in 1930. The prototype built in 1932 was already classified as a medium tank. The weight of the vehicle grew to over 20 tons and the armour was thickened from 30 to 40 mm. Theoretically, this protected the tank from the 25 mm cannon. The armour of the Char B1 grew to the same thickness around this time.
Char D2, the successor to the D1, a fully fledged medium tank. This tank fell victim to the "battle tanks". Only 50 were built. This tank was De Gaulle's workhorse, who considered it the best candidate for France's main tank.
The issue was that the French army unified its tanks' turrets. It's as though Estienne and his colleagues refused to see what was happening in the rest of the world. The British Medium Tanks Mk.I and Mk.II as well as the Vickers Mk.E had two-man turrets. There were many issues with the Renault FT turret. The same person had to aim the gun and machine gun, load them, observe the battlefield, and command the rest of the crew. The French continued to evolve concepts that went out of date in the 1920s. The rest of the world had time to get over the "tankette epidemic" and move on to mass produced light tanks with bulletproof armour and a heavy machine gun for armament. Even these tanks had two-man turrets. The USSR started building light tanks (with the exception of small reconnaissance tanks) with two-man turrets and 45 mm cannons. Nobody in their right mind built medium tanks with turrets that fit fewer than two crewmen. Nobody, but the French.
Development of the Char B1 became the priority after limits on weight disappeared. French command did not mind the fact that production of the first and only batch of 32 Char B1 tanks took almost two years. To compare, it took less than a year to build 50 Char D2.
The situation developed in an even stranger fashion after 1933. Germany officially left the disarmament commission on October 23rd, which triggered an arms race. The Char B1 was the most developed tank available at the time, and it became the priority. As for the Renault D2 it still needed more work, and in any case high command considered the B1 superior. However, a light tank program was launched in 1933 that was clearly meant to replace the Renault FT. The 6 ton tank would have the same armament, but have thicker armour. The requirement was initially for 30 mm of armour, later 40 mm. As with the Char D2, this armour theoretically protected the tank from the 25 mm gun. 14 companies took part in the tender; Renault won with its ZM tank. Its mass grew rapidly as a result of improvements, and reached almost 11 tons when the Renault R 35 entered production. There was another finalist in the tender: the FCM 36. A strange situation took place where the successors to the Renault FT fell into three separate classes: light, medium, and heavy.
The Renault R 35 was a return to the Renault FT concept. The issue of insufficient light tanks was solved in a characteristically French way: putting two tanks of the same class into production, which were later joined by a third.
Development of tanks for cavalry was separate from those used by infantry. Officially, the cavalry had no tanks, and these were classified as armoured cars. The cavalry was a lot more reasonable about tank development, but had its own nuances. Reconnaissance was performed by AMR 33 and 35 tanks armed with machine guns. These were quite modern and very mobile tanks for their time.
The AMR 35 ZT tank, the French cavalry's vision of a reconnaissance tank. It was armed with a 13.2 mm machine gun and its characteristics with on par with similar tanks in other nations, although only 87 units were built.
"Armoured cars" from the AMC family received a higher priority. At first these actually were armoured cars and halftracks, but tanks were preferred by the early 1930s. The AMC 34 (Renault YR) was the first of its kind. Only 16 were produces. At first, these tanks were built with the APX-1 CE turret like the one on the Char D2 and Char B1, but later they received the APX-2 two-man turret. This was the first case of a two-man turret used on a French light tank. The issue was that the cavalry was run on a shoestring budget and the AMC 34 was an exception rather than the rule.
SOMUA S 35. Officially, this was an armoured car, but actually this was the best French tank. However, the initial idea of a three-man tank with a one-man turret reduced its effectiveness.
The cavalry also had its own issues on par with those of the infantry. The greatest example was the development of an "armoured car" even larger than the AMC 34. Development of a three-man tank with a dedicated radio operator began in 1934. The story of the D1/D2 tanks repeated itself. The result was the SOMUA AC 4, accepted into service as the SOMUA S 35.This was the best French tank developed before the war. This tank was analogous to the Char D2 and had a similar turret, but it was much more reliable and mobile. However, it was quite expensive, and SOMUA could not meet the cavalry's needs on its own. As a result, the Hotchkiss H 35 tank was also accepted into service. This was a two-man light tank designed to replace the Renault FT. It had practically the same features and drawbacks as the Renault R 35, but it was more mobile and more reliable. The French cavalry moved from original vehicles to more mobile analogues of infantry tanks.
The experimental Renault ACG 1, also known as AMC 35. This vehicle had decent characteristics including a two-man turret, but the design was too unpolished.
The cavalry had a third "armoured car", a further development of the AMC 34. This was the AMC 35 (Renault ACG 1), an improved AMC 34 with better armament. This was the most numerous French pre-war tank with a two-man turret, but also the most problematic one. The reliability was quite poor an remained at this level until the start of WWII. The tank did not surpass the Hotchkiss H 35 or H 39 in mobility, even though its armour was worse.
The Hotchkiss H 35 was a litmus test for French tank development. This vehicle was initially developed for infantry, but lost the tender and was used by the cavalry instead. Ironically, the H 35 and H 39 were used more by infantry than cavalry.
As a result, France had 5 types of light tanks, 2 types of medium tanks, and 1 heavy tank in production by 1937. By this point the Char B1 went through a modernization and turned into the Char B1 bis. No other nation could afford the luxury of having 5 different light tanks, but only 50 D2s were built as a result. The tank design was mothballed for several years. The situation where the cavalry had more medium tanks than infantry was absurd and unthinkable in any other nation. When deliveries of the Renault R 35 began, the infantry realized that it had a ton of issues with its running gear and also ordered the Hotchkiss H 35. As the cherry on top, development of superheavy tanks for the Maginot Line resumed in 1936. Initially these were 45 ton versions of the Char B1, or an even larger replacement for the Renault FT with even thicker armour. The crisis of ideas reached a critical stage. The longer it went on, the worse it got. By 1940 these superheavy tank designs reached the mass of 139-145 tons, but they were increasingly less useful.
An AMX superheavy tank, 1937. This was a rehash of General Estienne's 1921 concept.
The chaos in the high command's head can be best illustrated via the Char G program. On September 16th, 1935, two weeks after the decision to put the SOMUA S 35 into production was made, the infantry prepared requirements for a new 20 ton tank. It was essentially the same as the SOMUA S 35, but with a top speed of 50 kph. This illustrates that the infantry was no stranger to fast tanks. However, the situation changed in 1936. The French infantry wanted to have two tanks on the same chassis, the Char D and Char B. A 75 mm howitzer was added to the front of the hull. The six companies that were building prototypes had to rapidly change their designs. The only tank build according to the initial specifications was the Char G1P built at SEAM under the direction of Andrey Ponyatovsky. The 26 ton tank with an electromechanical transmission entered trials in December of 1936. The trials were a failure. Instead of a top speed of 40 kph it could only reach 14 kph. The G1P quickly became obsolete since the French changed their requirements yet again.
The experimental G1P was the only G1 tank that reached the prototype stage, but it showed itself quite poorly.
One reason for the change was the success of one of the competitors: Renault. It decided to deviate from the requirements and do something on its own. The result was a tank that could be equipped with either a 75 mm L/32 gun or a 47 mm gun with a muzzle velocity of 800 m/s. The tank indexed Renault ACK didn't differ just in its armament. The size of the turret was minimized and the crew was practically sitting in the hull. The mass of the tank was 25-26 tons. The tank looked promising, but the turret developed by Lieutenant Colonel Balland was criticized. Further development was supposed to go along the lines of the Renault ACK, but with significant improvements.
The initial variant of the Renault ACK with a long 47 mm gun.
Calculations by the STCC and ARL showed that the vehicle would exceed the 20 ton weight class without a chance to reduce the mass. The weight limit was raised to 35 tons on February 1st, 1938. The Renault G1R was lighter than that, just 32 tons (if the Renault-Balland turret was used). Alternative turrets were developed in 1938-39, heavier, but not as complicated. These turrets were developed at FCM and ARL, but only textual descriptions remain.
An illustration of the complex Renault-Balland turret from the patent application. The turret fit two crewmen, but they practically sat below it.
The results of the Char G program were sad. The G1R didn't even reach the prototype stage, as only the hull was ready by June of 1940. The Baudet-Donon-Roussel (BDR) variant was luckier. It never evolved into a full fledged tank, but its chassis was used for the ARL V 39 SPG. This was also the fate of the 20 ton SOMUA tank. Elements of its design were used in the creation of the SOMUA SAu 40. Both vehicles remained prototypes, although mass production was planned.
The final Char G1R variant was supposed to have a 75 mm gun and a weight of 32 tons (or greater, considering how French tanks tended to gain weight). Even the most optimistic variant weighed more than 10 tons over the initial requirements.
The Char G was not the only vehicle that shared its fate. In June of 1937 the AMX design bureau (the Renault factory nationalized in 1937) began working on a replacement for the Renault R 35, FCM 36, and Hotchkiss H 35. The AMX 38 was supposed to fit into the 10 ton weight class, but didn't manage to. The prototype built in the spring of 1939 weighed 13.5 tons. The variant with a 47 mm SA 35 gun weighed 16.5 tons. This was not the end. The last iteration received 60 mm of armour and reached the 20 ton mark. This was essentially a medium tank with a crew of two. Hello again, Renault FT!
The experimental AMX 38 prototype. As a result of requirements creep, the light tank would have weighed no less than 20 tons in production.
The overall prospects were grim. The French entered WWII with a tank fleet composed of supersized versions of tanks developed in the 1920s. Most of these tanks were overweight, which affected not just mobility, but reliability. An overloaded chassis also has no possibility of modernization, which is quite important in wartime. There were no alternatives, and even the deaths of Estinee and Velpris changed nothing. Louis Keller was appointed to the post of Inspector of the Tank Forces in August of 1939. His views didn't differ from those of his predecessors. Under Keller, heavy tank projects reached a mass of 150 tons and projects of thick-skinned monstrosities multiplied like rabbits. Rational voices like those of Colonel Charles de Gaulle that insisted on medium tanks fell on deaf ears.
No chance at victory
Such a bleak view of French tank development may create the illusion that only the French had it this bad. This was not the case. A crisis of ideas can be observed in nearly every tank building nation of the period. The Germans didn't come up with their medium tanks right away (and the most numerous German tank, the Pz.Kpfw.IV, attained this status by accident), and the light tanks were far from ideal. The fact that the Pz.Kpfw.I had no future became clear in Spain, but the Pz.Kpfw.II was a typical light tank of the mid-1930s: it stood little chances against new French tanks with its 20 mm autocannon and 15 mm thick armour. German light tanks also had one-man turrets. As for the Pz.Kpfw.III, it only reached anything resembling mass production in the fall of 1939.
The core of British and American tank forces was made up of light tanks armed with machine guns that were about on the same level as the Pz.Kpfw.II. Czechoslovakia and Poland also failed at building medium tanks, although Italy and Japan managed to make something resembling a medium tank towards the start of WWII. The USSR was in the best position, but with caveats. The new generation of tanks (T-29, PT-1A, T-46) was a failure, as was development of SPGs. There were also difficulties with development of tank guns. Real replacements came only in 1939 and entered mass production in 1940. A replacement for the T-26 only came in 1941, and never entered true mass production. Everyone had their own issues.
Penetration trials of a Renault R 35 led to unexpected results. It turned out that 40 mm thick cast armour could be penetrated at a range of about 300 meters.
In this case, the more important question was whether or not a nation's industry could produce sufficient amounts of high quality tanks. This is where issues with French tank industry become clear. As mentioned above, one of the most important issues for tanks of the new generation was armour. The Renault R 35 and Hotchkiss H 35 had 40 mm of cast armour, while the FCM 36 had rolled armour joined by welding. Cast armour was easier to manufacture, but not as robust. In June of 1937 it turned out that the German 3.7 cm Pak penetrated a Renault R 35 in trials in 14 cases out of 18. The 25 mm gun also penetrated its armour in 50% of cases. The interest towards the FCM 36 increased after these trials, but it never became a truly common tank. Not only was the FCM 36 expensive and complex, but FCM devoted much of its attention to the Char B1 bis program.
This Renault R 35 was knocked out by anti-tank guns.
The situation with the armour of the Renault R 35 meant that practically all light and medium tanks were vulnerable to enemy anti-tank guns. Once again, the author cautions comparing tanks with characteristics alone. French tanks were meant to combat fortifications, artillery, and infantry, not enemy tanks. The ability to defeat its armour with 37 mm guns from 300 meters was a bit issue. The odds of meeting one of these guns in an ambush were much higher than the odds of finding a German tank. One of the biggest issues of French tanks was poor visibility. The commander's cupolas were not very good, nor were the observation ports. Additionally, the commander had to perform many other tasks. Additionally, few French tanks had radios, which made communications an issue.
French tanks started getting long 37 mm guns only in 1940. Even these guns had very humble penetration parameters.
There was another issue with light tanks: armament. The 37 mm SA 18 gun was considered sufficient in the early 1930s. In practice, its HE shell was weak and AP shell was about as effective as a heavy machine gun. This is why the Americans rejected similar guns. The French realized the real abilities of the SA 18 only towards 1938. Work hurriedly began on the SA 38, which entered production in 1940, not 1938 as its name implies. This gun had better penetration than the SA 18, but was still only capable of penetrating 29 mm of armour at 100 meters. In practice, French tanks with the new gun could defeat only enemy light tanks, but applique armour was installed on Pz.Kpfw.II tanks starting in the spring of 1940. As a result, only AMC 34, AMC 35, and AMR 35 ZT2 cavalry tanks could achieve any results on the battlefield. They numbered less than 100 put together.
Experience in May-June of 1940 showed that 47 mm guns were the most effective. Even the obsolete Char D1 fared better than new generation French tanks.
The protection of Char B1 bis tanks was quite a bit more effective. Some say that these tanks were practically invincible, but that was not the case. Yes, they did have 60 mm of armour all around and managed to show exceptional resilience in some cases, but this was more the exception than the rule. The Char B1 bis had its share of weak spots: the driver's vision port, air intakes on the side, running gear. Cases where tanks were hit in these points were common. Second, the greatest enemy of the Char B1 bis was the tank itself. Recall that the prototypes weighed 25 tons, the production Char B1 weighed 27 tons, and the Char B1 bis ballooned to 32 tons. Of course the running gear was reinforced and a more powerful engine was installed, but the extra 7 tons of weight had a negative effect on the tank's reliability. Recall also that the French high command was expecting the 36 ton Char B1 ter tank to enter service. Third, tank on tank battles didn't happen that often. The most common enemy was German infantry, and it had more than just the 3.7 cm Pak. 105 mm leFH 18 howitzers were often used against tanks, as well as 88 mm Flak 18 guns that were reclassified as dual purpose weapons in 1938. The use of the "acht-acht" against tanks wasn't improvisation.
A typical end to the career of a Char B1 bis tank. Crews often demolished their own tanks, although German artillery claimed its share.
Even if one discounts French tank tactics and the supply situation, the outlook was grim. The Renault FT remained the most common French tank as of September 1st, 1939, and its various replacements had their share of drawbacks. They were of course troublesome for German infantry, but did not have the effect that French commanders expected. Heavy tanks worked a lot better, but their successes were localized. Medium tanks could have been a solution, but the French infantry had only 50 of them, and they were quite worn out. The situation was so critical that a portion of Char D1 tanks returned from Africa. Even these obsolete medium tanks were more effective than the new generation of light tanks. The SOMUA S 35 was the best French tank of WWII, even though it was classified as an armoured car. The Hotchkiss H 35 (and also its upgraded version the H39) had its share of problems, but at least they had decent mobility.
Combat showed that the SOMUA S 35 was the best tank France had. The problem was that there were quite few of these tanks in sectors where Germany struck, plus French tank tactics raised a few questions.
Let's move on from quality to quantity. The Anschluss of Austria and subsequent events took place not just for political reasons, but also for military ones. To summarize, the French suddenly discovered that they had little to oppose the Germans with. By April of 1938 the French had just two regiments with medium Char D2 and heavy Char B1 tanks. The first contract for the Char B1 bis was only concluded in the spring of 1938. About a hundred SOMUA S 35 were built, a portion of which were already issued. The Germans didn't have many more modern tanks, but their main counterpoint to tanks was artillery. The British were even worse off, as their army did not have even a single modern medium tank. In other words, the appeasement policy bought time to move industry to war footing.
Assembly of a Char B1 bis tank. Five factories were involved in production, but it was still behind schedule.
The situation was not as critical by September 1st, 1939, but the "sitzkrieg" was no accident. By September 2nd, 1939, the French infantry had 975 Renault R 35 tanks, 98 Hotchkiss H 35 tanks, 200 Hotchkiss H 39 tanks, 100 FCM 36 tanks, 2850 Renault FT tanks, 160 Char D1, 50 Char D2, 149 Char B1 and B1 bis and 6 FCM 2C. The cavalry had 120 AMR 33, 190 AMR 35, 12 AMC 34, 16 AMC 35, 300 Hotchkiss H 35, 16 Hotchkiss H 39, and 246 SOMUA S 35. This looks like an armada, but that is not quite so. There were many organizational issues, plus the obsolete Renault FT made up a good two thirds of infantry tanks. There were also issues with the Renault R 35. It's no coincidence that these were the only new French tanks that were authorized for export. There were only enough Char B1/B1 bis to equip three regiments, which were reformed into tank battalions in August of 1939. The French had a serious chance to deliver Germany if not a defeat, then a serious blow. However, the aforementioned organizational issues struck. All the French could do was put together the Saar Offensive, which quickly petered out.
Assembly of the SOMUA S 35 was an example to follow among French tank manufacturers. SOMUA built 20-22 tanks per month. The Germans didn't manage any more than that within one factory. The issue was they had many more assembly plants than their western neighbour.
A rush to build up forces followed on both sides of the front. The French army began to rapidly lose its advantage. The Germans bet on medium tank production, but the primary French tank was still the heavy Char B1 bis. This was a fatal mistake. The expensive and overloaded tank would never be available in sufficient numbers.
FAMH, FCM, and Schneider joined in to build the Char B1 bis before the war. AMX joined the program in November of 1939. Production grew gradually, but not at the required rate. Even at the peak of production in March of 1940 only 45 tanks were being build monthly. Meanwhile, SOMUA put out 20-22 tanks by themselves. The Germans went a different route. Production of the Pz.Kpfw.II dried to a trickle by the summer of 1939 and stopped in December. The Pz.Kpfw.III was a priority. It was being built at 6 factories simultaneously, later 7. The result was clear: 157 Pz.Kpfw.III were built from September to December of 1939, even though the design had to be improved in many ways. 258 tanks of this type were delivered in the first five months of 1940, and this is while German factories were not yet at their full potential. 149 Pz.Kpfw.IV and 227 Pz.Kpfw.38(t) tanks were added to the existing forces between September of 1939 and May of 1940. New German tanks outnumbered the French.
The AMX factory after being captured by the Germans. At the moment it was building Char B1 bis and Renault R 40 tanks.
French factories deserve a separate mention. Key factories (Renault, AMX, Hotchkiss, APX, ARL) were all located around Paris. The same was true for 100% of factories that built tank armament. When the Germans neared Paris in June of 1940, the French lost nearly all of their tank production as well as production of tank engines and cannons. Resistance was pointless after that. Also note that in 1940 French factories worked at their limits and as a result the quality rapidly declined (this was most noticeable within the second batch of Char D2 tanks). Many complaints about the tanks came from end users. There is no such thing as miracles, and one has to pay with quality for increased quantity. What's worse, the French had no other means of increasing production volumes, left. The plans for putting the ARL V 39 and SOMUA SAu 40 into production looked a bit naive, as the only way this could be achieved was by sacrificing tank production. No "France 1941" that alternate histories salivate over was possible. Even if the Germans were held back in May-June of 1940, defeat was only a matter of time. The Germans surpassed the French in both quality and quantity of tanks.