Friday, 22 December 2017

The First Classic Tank

France was the second country in the world to equip itself with tanks. The French were about half a year behind the British, but their designs were a lot more progressive. The French army had the most tanks at the end of WWI, and quality came along with this quantity. At this point, the Renault FT was the backbone of the French armoured force. This was the most numerous tank of its time, the first mass produced light tank, and the first tank in the world of a layout that was later deemed classic. What is the story of the creation of the Renault FT?

Less is more

French tank building followed the path that British tank building took, at first. After considering various projects of wheeled and tracked armoured cars, the French, like the British, turned to Holt company tractors. The difference was that the French picked the Holt Baby, while the British chose the Holt 75. The Holt Baby served as the foundation for the first French mass produced tank, the Schneider CA.1. On February 25th, 1916, the Schneider company received an order for 400 tanks. The second medium tank, the Saint Chamond, was built on a similar chassis. The French army ordered 400 of them.

The fact that the French could have had a third medium tank is less well known. On May 20th, 1916, General Moureu, the head of the STA (Service Technique Automobile, the French artillery mechanization branch), visited the Renault factory in Boulogne-Billancourt. The result of this visit was an order to develop a medium tank. The project was ready on June 29th, 1916, but work did not progress past paper.

The Renault FP tractor was an offshoot of this project. Like the tank, it was based on the STA-Fouche chassis, developed by Lieutenant Charles Fouche, one of the key figures of the French tank design program. Fouche's work in STA paved the way for the creation of the first French tanks.

A suspension patented by Ernest Fuchs used on the Renault light tank.

One of the causes for shutting down the Renault medium tank program was a conversation between Loius Renault and Colonel Estienne in July of 1916. The main ideologist of French tank building talked to Renault in the past. For example, in 1915, they spoke about a medium tank, but Renault was loaded with other orders. The conversation in 1916 was about a different vehicle. Estienne visited England in the spring, where he familiarized himself with the British tank program. From that visit, he drew the conclusion that light tanks are needed to accompany medium tanks. These tanks were more akin to mobile machinegun nests and would be much more numerous than medium or light tanks.

The idea piqued Renault's interest, since this tank could be built with automotive components. He named the tank in a British style: "tank patrouilleur", "patrol tank". Charles Serre, Renault's technical director, oversaw the work on the tank. The development was headed by Rudolph Ernst-Metzmaier.

It is often said that the new tank was based on the Schneider CA.2 designs, but that is incorrect. First of all, the tanks have almost nothing in common. Second, work on the SA.2 began in October of 1916, when work on the Renault tank was already in progress. By then, Ernest Fuchs was already finished designing the tank's suspension.

A full scale model of the "tank patrouilleur", October 1916.

Renault completed a full scale model of the tank in October of 1916. The vehicle was radically different from anything else designed during that time. The Renault 18CV engine was installed in the rear, and was separated from the crew by a bulkhead, which was a big step forward as far as ensuring crew comfort went. The driver was placed up front. The commander/loader/gunner was standing behind him. The commander's machinegun was located in a rotating turret.

To be fair, the first tank turret appeared on the British "Little Willie" tank, but it was quickly discarded. Nobody was going to remove the Renault's turret, as it radically increased the agility of fire. To increase the tank's mobility, the designers brought out its large idlers as far forward as possible.

A model of the Char leger, December 30th, 1916. Rudolph Ernst-Metzmaier is standing in front of the tank. He is often mixed up with Louis Renault. Note: not every man standing in front of a Renault FT is Louis Renault.

Estienne, who was a general at that point, liked the Renault tank concept. However, General Moureu did not share his enthusiasm, as he was rather sceptical about the idea of light tanks in general. However, Estienne managed to get around him and obtain permission from General Joffre, the Commander-in-Chief of the French army. Estienne's letter with his ideas about light tanks was sent to Joffre on November 27th, and the approval arrived on November 30th.

Fierce arguments about tank building broke out soon after. General Nivelle, who replaced Joffre in December of 1916, had a very conservative opinion about tanks. Instead of light tanks, he wanted to build 300 artillery tractors. There were other forces at work against Estienne and Renault. Nevertheless, Renault received permission to produce a "Renault tracked tractor, project #11" on December 12th, due in March of 1917. It was also called "Char leger", or "light tank". The project was called Renault FT at the factory, as the project after the Renault FS, a car equipped with the same engine.

The Renault FT's initial look, winter of 1917.

A full sized model of the improved variant was demonstrated on December 30th. The biggest difference was the turret, designed by Colonel Émile Rimailho, the FAMH technical director. The turret became roomier and easier to make.

The tank became the subject of a heated discussion. Moureau and his allies tried to cancel the decision to produce the tank, claiming it was too light and weakly armed. They did not have enough votes to succeed. Of the 10 members of the Consultation Committee that made the decision regarding the Renault tank, only three voted against its production. A decision was made to produce 100-200 tanks. The final number of 150 tanks was approved by the Minister of Munitions, Albert Thomas, in February of 1917. Thomas also thought that artillery tractors were more important than tanks. The first light tank was not created in hospitable conditions.

The same tank from the front. Note that the driver's hatch still consists of one piece.

The first experimental light tank, also named Char mitrallieur Renault (Renault machinegun tank) was ready by the end of January 1917. The layout was the same as the full sized model, but the design had many differences. For instance, the 4 ton weight limit that Estienne requested was not met. The tank weighed 6.5 tons. However, this was not a big issue.

The design of the hull changed drastically during production of the prototype. This happened because the components in the engine compartment were rearranged, and the driver's working conditions were improved. Another useful addition was the "tail", which helped the tank cross trenches.

Loius Renault driving a Renault FT tank, February 22nd 1917 (This time it really is Louis Renault).

The turret was completely redone. It became somewhat smaller, but the design was better than before. Not only was this tank the first to receive a turret, but it was the first to have a commander's cupola. The turret contained observation slits and did not initially have a hatch on top. Another improvement was the Hotchkiss Mle.1914 machinegun mount. On the model, it could only move vertically, but the prototype had a ball mount.

The same tank in April of 1917. The commander's cupola has an air vent due to issues with ventilation.

The first test drives took place in January. Wary of lightning fast reaction from the tank's opponents in case of any failures, Estienne and Renault were not in a hurry. On February 22nd, Louis Renault held a driving demonstration in the factory courtyard, the first time the tank was shown. Later, the vehicle was transferred to the assault artillery center in Champlieu. Unofficial trials began on March 14th, where defects were fixed as they cropped up. The tank was returned to the factory, where repairs and modernization took place.

An experimental vehicle with the final turret configuration.

The moment of truth came on April 9th, 1917. Official trials took place on that day, again in Champlieu. It was clear that the vehicle was a success. The consulting committee not only approved of 150 vehicles, but accepted Estienne's proposal to build 1000 tanks. Even Nivelle was forced to five up and give his approval, which he did on April 13th.

The fact that the tank was accepted did not mean that it was devoid of drawbacks. The turret filled with fumes when the gun was fired, and the problem with ventilation had to be solved. The turret was altered in May. An air vent appeared on the commander's cupola, and the turret increased in size.

Light competitors

The launch of work on the Renault FT did not go unnoticed. When Joffre gave his permission to Estienne, the fact that Renault was working on a light tank ceased to be a secret. As mentioned above the French tank industry was host to a fierce competition. As soon as it became known that there was a new opening, work started.

The rear of the production Renault FT was different than on the prototype.

Schneider-Creusot were the first to react to their competitor. A project of a miniature tank, somewhat similar to the Schneider CA.2, was presented on December 29th, 1916. The fighting compartment was in the back, and the engine was in the front. Two types of tank were proposed: with and without a turret. However, the proposal was quickly rejected, since it was inferior to the Renault FT, and the miniaturization had negative effects.

Delaunay-Belleville from Saint-Denis also tried its luck in tank design. The company's main product was luxury cars. Tanks were also far from Renault's main source of income. Delaunay-Belleville didn't reinvent the wheel, but took the Schneider CA.1 chassis and shrunk it by 15%. The engine was placed in the back, and a casemate that was supposed to house a cannon and a machinegun was put in the middle. It's hard to say that this 2.75 ton tank concept was bad, but it was inferior to the Renault FT in every respect. This was the biggest reason why the proposal was rejected. Two years later, the idea of a super-light tank returned, but this time it was brought to life abroad.

The Renault FT's competitors never left the drawing board.

A more serious competitor arose in early 1917. General Moureu, who was not a fan of the Renault FT, decided to launch a backup plan to be safe. He chose another automotive company as the contractor, Peugeot. Real work began in March, when engineer Oemichen joined the project. He worked on Peugeot cars before the war, and later became Estienne's technical consultant. 

Peugeot's light tank looked like this initially.

Unlike engineers from Schneider or Delaunay-Belleville, who went the evolutionary route, Oemichen decided to be revolutionary. The layout of his vehicle was unlike any other project. The Peugeot engine was placed in the front, which generated electricity for the electric motors in the rear. The suspension was conceptually similar to the Renault FT. The number of road wheels per side decreased to 4, and the suspension had a complicated design. The track links were also more complicated.

The final design of this vehicle. Better armoured and better armed than the Renault FT, this tank was never mass produced.

Delays in the design process led to the Peugeot light tank only being finished in September of 1918. The result was a rather unusual vehicle that, at best, could have aimed at filling some other battlefield requirement, but not the replacement of the universal Renault FT.

Oemichen changed the concept along the way, and decided to build a fire support tank instead of a light machinegun tank. The 75 mm BS howitzer was used as armament. Instead of a rotating turret, it was installed in a casemate, with impressive armour that was up to 40 mm thick. The driver was placed to the right of the gun. Even though the 100 hp Peugeot engine was more than 5 times more powerful than the Renault FT's engine, there was no significant boost in mobility. The tank's mass was 9 tons. Such was the price of thick armour.

The Peugeot light tank was rather cramped. There was also little need for it at the end of the war.

Trials held in the fall of 1918 showed that Oemichen's design was rather flawed. On one hand, the tank was well protected and could reach a respectable speed of 12.5 kph. On the other hand, the 4 kph advantage over the Renault FT was not much. The shorter Peugeot tank was also not as good as the Renault FT at crossing trenches. The short barrelled gun was a weapon with narrow applications and low maneuverability. There were already Renault FT 75 BS artillery tanks that had the same weapon, but carried in a rotating turret. Only one prototype of the Peugeot tank was built.

After WWI, Oemichen managed to attain success in a completely different field: helicopter design.

Satisfaction for all

The production of 150 Renault FT tanks did not mean that they would be immediately sent to the front lines. A decision was made to produce the first tanks as training vehicles, with hulls and turrets made from mild steel. This idea seems strange, but it had its reasons. For starters, it was necessary to work out the production process before starting proper production. Additionally, the French army never had light tanks before. It was necessary to develop tactics for their use, which had to be different from medium tank tactics. The French military also expected that the tank's design flaws would become apparent during testing. This idea later proved correct.

Renault FT from the first production batch. May 15th, 1917.

The first three tanks of the training batch were produced at Boulogne-Billancourt in September of 1917. The tanks received serial numbers, starting with the digit 3, and registration numbers, the first of which was 66001. Overall, the tanks in the first batch were identical to the prototype, but there were differences. The "training" tanks had distinctive cast front and rear hull sections.

In addition, the uncomfortable one piece driver's hatch was replaced with one in two pieces. The new hatch was tested on the prototype, which was used for various experiments. The rear of the tank also changed somewhat. The ventilation openings in the sides were deemed a poor choice and removed. The turret was also altered. A bulge was added to the commander's cupola, which improved ventilation.

Training tanks during assembly. Fall of 1917.

Work on the first batch progressed slowly. Renault delivered 18 tanks in October, 21 in November. 40 tanks left Boulogne-Billancourt in December, 32 in January, 35 in February, and the remaining 4 in March. The tank changed during production. One noticeable change was the addition of steps in the front to make the driver's life easier. They appeared during the second month of production.

This tank was sent to Great Britain and can be seen in the Bovington tank museum today.

Aside from the French army, 12 training tanks made it to Great Britain. One of them, the 13th production vehicle with registration number 66016, can be seen in the Bovington Tank Museum. This is the oldest of all remaining Renault FT tanks.

Cannon and machinegun mount diagrams.

The bulge on the commander's cupola was just the first of the changes made to the turret. Estinenne wrote to Joffre in November of 1916 that the Hotchkiss Mle.1914 machinegun was not the only option for the tank's armament. According to Estienne, a potion of the tanks should be armed with 37 mm infantry cannons. A candidate was found quickly: the Canon d'Infanterie de 37 modèle 1916 TRP. Its compact dimensions allowed it to be installed in a light tank without much issue. The APX company (Atelier de Puteaux), the gun's developer, quickly designed a tank version of the gun, which was indexed 37 mm SA (canon de 37 S. A. pour chars légers).

Armament used on main production run tanks.

In early April of 1917, a draft project of a modified turret was prepared at Renault. It was designed in cooperation with the Paul Girod company, which caused it to go down in history as the Girod-Renault turret. The turret is also referred to as "tourelle omnibus" in correspondence. The training tank turret served as the starting point. Its volume was increased by changing the front section. This allowed it to fit a 37 mm gun without issues.

Since the ball mount was inappropriate for the task, a new mount was designed. It looked similar to the machinegun mount on the tank's model. Since the gun still turned as well as pitched up and down, the gunner could aim it without turning the turret. By simply replacing the gun mantlet, the same turret could hold either a machinegun or a cannon.

The first tank with a Girod-Renault turret, July of 1917. A dummy is used instead of a gun.

The experimental turret was ready in May of 1917. In July, it was installed on an experimental Renault FT tank. A dummy was used instead of a cannon, but an order for 600 cannons followed on July 5th. In the fall, the turret changed a little, gaining "cheeks". This is how it was sent to production.

All three types of Renault FT turrets on one photo. The Berliet-Girod turret is closest, the Renault turret is in the center, and the Girod-Renault turret is furthest away.

On May 9th, 1917, Nivelle's position was weakened by a series of unsuccessful operations, and he was replaced as Commander-in-Chief by Petain, who was a fan of tanks. He favoured the Renault FT design, and the order for 1000 tanks was increased. On August 1st, 1917, a new order requested 2400 tanks from Renault at a cost of 44,000 francs per unit. This was comparatively cheap: a Schneider CA.1 tank cost 58,000 francs, and a Saint-Chamond cost 94,000 francs.

The order was redistributed in October of 1917, including a number of new companies. This included Schneider and Delaunay-Belleville, former competitors. Schneider delegated the work to its subsidiary, SOMUA (Société d'outillage mécanique et d'usinage d'artillerie). Renault gained a new competitor: Berliet, an automotive factory from Vénissieux.

The order for the first batch was split in the following way:
  • Renault: 700 tanks
  • SOMUA: 600 tanks
  • Delaunay-Belleville: 280 tanks
  • Berliet: 800 tanks
Tanks produced at SOMUA had serial numbers starting with 3001, Delaunay-Belleville tanks had serial numbers starting with 4022, Beliet's started with 2163. SOMUA registration numbers began with 69017, Delaunay-Belleville - 70017, Berliet - 73003. Some irregularities with numbering took place during production, but, overall, the system was kept within its bounds.

The distribution of the order between four factories meant that the companies worked closely together. This was the first such instance in the tank building world. Renault supplied its own engines, gearboxes, and all suspension elements, but was dependent on external turret and hull suppliers. There were five of them. Berliet made its own hulls and turrets, and the armour came from Paul Girot (for turrets), FAMH, and Imphy. Like Renault, Berliet made its own engines and suspensions. Delaunay-Belleville had a similar arrangement with armour manufacturers. The hulls and turrets were assembled here, but engines came from Renault and Berliet. Suspension elements were produced in Saint-Denis. Finally, SOMUA largely received its armour from Schneider and made its own suspensions. As for engines, 510 were built at Peugeot, the rest came from Renault. 

This kind of cooperation was key for successful organization of the tank's mass production.

A postcard featuring tanks from the most numerous variant: with a Berliet-Girod turret.

This kind of production affected the tank's look. The cast front and rear sections were removed. The turret also changed once more. Beliet and Paul Girod engineers began a new project in October of 1917. The result of this cooperation was the Beliet-Girod turret. It looked like the Girod-Renault turret, but the biggest difference was that it no longer had protruding "cheeks". This variant was the most common of the cast designs. It was used by all four factories.

The first prototype of the Renault riveted turret on a training tank.

Girod-Renault cast turrets were made in small numbers. Renault quickly turned their eyes towards a riveted design. It was easier to produce than their joint design with Girod. The result was the "polygonal" turret. Renault considered this variant a higher priority. 1147 turrets of this type were built, all of which were used on Renault tanks. Berliet-Girod turrets were also installed.

1680 Renault FT tanks were expected by the end of March of 1918 according to estimates made on November 2nd, 1917, but real tanks only started leaving the factories in March. APX just began producing guns around that time as well. Of 260 tanks delivered by May, only 60 were fully functional. According to the revised program, 4000 tanks were to be built in 1918, 3100 of them in regular configuration, 600 with the 75 mm BS howitzer, and 300 TSF tanks with radios.

Viewing new French tanks.

664 tanks were delivered by June 1st, 1918. Full scale production began in the summer. 372 tanks were built in June, 601 in July, 502 in August, and 592 in September.

The tanks first saw battle on May 31st, 1918. It was quickly discovered that the light tanks met their expectations. The low top speed was made up for by their low mass (6.5 tons for the machinegun version and 6.7 tons for the cannon tank), which allowed them to be delivered to the battlefield on trucks. They successfully accompanied infantry in battle. More than that, their appearance was often the only way to convince the infantry to attack. 100 years passed, and the tank remains the best way to motivate infantry.

By the middle of July, the Renault FT was the most numerous French tank. French tanks often supported British offensives. Rapid production allowed supplies of the FT to allies, primarily the Americans. By September 21st, 173 of these tanks were given to them.

Renault-produced tanks driving toward the front. By the mid-summer of 1918, not a single major French operation commenced without these tanks.

The success of the light tanks on the battlefield was followed by another order. It increased the expectations to 7800 tanks 3940 of which were to be built by Renault, 1955 by Berliet, 1135 by SOMUA, and 730 by Delaunay-Belleville. However, that number of tanks was never built. The armistice was signed on November 11th, and WWI came to an end. 3246 tanks were delivered before November 11th, and 627 more were finished by the end of the month. Production gradually wound down. Nevertheless, new tanks were still being delivered in 1919. Overall production reached 4516 units. The breakdown between companies was as follows:
  • Renault: 2620 tanks
  • SOMUA: 481 tanks
  • Delaunay-Belleville: 390 tanks
  • Berliet: 1025 tanks
The Renault FT deserves its reputation as the best tank of WWI. It was inferior to the medium and heavy tanks in firepower, but superior in numbers. Its small mass and ability to be transported in trucks radically boosted its tactical mobility. The crew's working conditions were also significantly better than those of other WWI tanks. The Renault FT became a subject of imitation, as well as the first tank to be built abroad under license. Its fighting career stretched out for decades.

Towards the end of the war, the Renault FT received an unexpected enemy: General Estinenne. At that point, he decided that the future is with medium tanks. That led to the start of the Char B concept.

A victorious display in Paris. The Renault FT earned its place in the parade. The tanks remained the backbone of the French army for more than 15 years.

To conclude, let us return to the name "Renault FT". The issue is that the tank is often called FT-17. In reality, this has nothing to do with its real name. The tank was officially called Char d’assault 18 HP (18 hp assault tank). So where did the index come from?

The fault lies with a group of authors responsible for the Taschenbuch der Tanks encyclopedia in 1935. Researchers often use this encyclopedia as a main source of information, but they shouldn't. The book contains a large number of mistakes and fabrications.

The Renault FT was a victim of one of them. To make life simpler for themselves, the authors named the Renault FT with a "polygonal" turret Renault M.17 FT and the Berliet-Girod cast turret variant Renault M.18 FT. Even the German Land Forces Directorate took this book for gospel and used the indexes contained within actively.

From here, the name "Renault FT-17" spread across many pages of literature. I would like to recommend that researchers stop blindly copying an 80 year old book and begin to study modern research, especially that of François Vauvillier and his colleagues.

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