Tank destroyer design – None built
The liberation of France began in June of 1944 and was mostly concluded, with the exception of a few areas towards Alsace and some western ports, by the end of August of the same year. Rebuilding France’s military industry quickly became a new priority for the French government. Once a world leader, the French military industry had been considerably weakened by years of German requisitions and Allied bombing. If France wanted to retain an important and independent place on the world stage, a healthy military industry would prove a massively useful tool.
The first phases of the French military industry getting back on its feet often took the form of pre-1940 vehicles being modernized to suit modern needs (such as the Panhard 178B, the first armored fighting vehicle produced by France post-war), or pre-1940 hulls being modified to fit roles other than fighting tanks. Within these, one could name three tank destroyers projects which were submitted by the Atelier Mécanique d’Issy-Les-Moulineaux (AMX) in November of 1945, mating the hulls of two pre-1940 French tanks, the R35 and S35, with the British 17-pounder anti-tank gun.
There were three different proposals for 17-pounder-armed tank destroyers based on old French hulls. One was designed on the S35 hull, and used a forward-firing gun. Two were designed on the R35 hull, one with a forward-facing gun and more ammunition stowage at the cost of being nearly a tonne heavier, and one with a rear-facing gun and more limited ammunition stowage, but about a tonne lighter. Both R35-based projects are dated from the 8th November 1945, and as such, it is impossible to estimate whether one precedes the other.
As for the choice of the old French tank hull, while a number of R35s were seized after the liberation of France, this number remained limited, and the project was most likely never seriously intended for production. Instead, it likely was a proof-of-concept and a way for AMX’s engineers to get back into designing armored vehicles on the basis of familiar components.
This R35-based tank destroyer made major changes to the original vehicle, which would be needed to accommodate a gun as large as the British 17-pounders. The upper hull and turret were completely replaced by a new, much bigger open-topped armored superstructure. The removal of the turret and upper hull would free the tank of 2,860 kg, with the new superstructure – on its own – only weighing 800 kg. This small weight was likely accomplished by a very thin construction. The casemate was open-topped, though it reached high enough for a crew member standing on the vehicle’s floor to not stick out of the vehicle from a point of view at the same level of the vehicle, which would mean the vehicle would not be as vulnerable to firearms as other open-topped designs. However, it would also massively increase the silhouette of the R35. The casemate peaked at 2.17 m, in comparison to the R35’s 1.92 m.
The casemate mostly used welded construction. However, rounded corners as well as the rear section where the gun was located were cast instead. This formed a bulbous shape extending towards the barrel’s direction. The vehicle used the British 17-Pounder, one of the more powerful anti-tank guns fielded by the Allies during the Second World War. When facing the rear, the gun would need to be placed pretty far rearward in order to offer sufficient space to be operated properly within the casemate. This meant that this casemate extended rearward on top of the engine compartment, and the gun obviously extended further towards the rear. The overall length of the R35 was extended from 4.02 m, counting only the hull, to 6.22 m counting the 17-Pounder. The vehicle’s configuration, with not only the gun but even the casemate somewhat extending over the engine deck, would likely highly complicate the maintenance of the R35’s powerplant.
The 17-Pounder in itself weighed 1,630 kg in the form that was mounted in the R35 tank destroyer. This was mounted with a gun mask on a movable mount, all weighing 280 kg. This would allow for a lateral traverse of 21° to each side, an elevation of +22°, and a depression of -9°.
The tank destroyer would retain the same engine as the R35, meaning a Renault 447 4-cylinders engine producing 85 hp. The rear-facing tank destroyer version was planned to have a fairly similar weight to the R35 – only raising the weight from around 10.6 tonnes (up to 11 in running order) to 11.046 tonnes, with the power-to-weight ratio only being reduced from 7.7 to 7.6 hp/tonnes. To be fair, this was already quite little, with the R35 being generally a somewhat anemic tank, rated for 20 km/h (up to 23 km/h according to Soviet trials of a captured example).
The center of gravity of the tank would be somewhat modified by the changes. It would be brought a little higher up and towards the rear, going from around the third roadwheel and the height of the sitting driver’s knees to the front of the fourth roadwheel, and the height of the driver’s torso. This would, however, remain fairly reasonable.
Internal Arrangement, ammunition stowage, and crew
In the known schematics, the R35 tank destroyer is portrayed with two crew members. The driver retained the same driving position as the R35, meaning he would be located at the center of the hull. The other crew member portrayed would if he was the only one, operate the 17-Pounder gun and command the tank all on his own, unless the driver would leave his position in combat operations, or if a third crew member would be present – which appears somewhat realistic seeing the casemate’s dimensions – and was just not portrayed in the schematics.
The gun was located on the higher part of the casemate, with the breech located around the level of an average crewman’s neck. On its sides, in parts of the armored hull that advanced inward to form the shroud-type armor surrounding the gun, a ready-rack for 6 rounds was located on each side of the gun. A further ammunition locker containing 30 rounds was located on the left of the hull, below the gun and just in front of the engine compartment. In total, ammunition stowage would account for 966 kg (included in the planned 11,066 kg weight figure). If it had fired all of its ammunition, this R35-based tank destroyer would have lost more than 8% of its weight.
Conclusion – A poor Frenchman’s Archer
This R35-based 17-pounder tank destroyer was not the only tank destroyer design using the British gun in a rear-mounted fashion. This rear-faced configuration had, in theory, some advantages, notably the ability to retreat immediately after firing and had even been used in a French 1940 wheeled tank destroyer, the Laffly W15 TCC. The same configuration had been used by the British for the Self Propelled 17pdr, Valentine, Mk I, more often than not known as the “Archer”. The Archer, however, used a hull much more well-suited to the task of mounting a gun as heavy and large as the 17-Pounders – the heavier and longer Valentine hull allowed for a more reasonable, lower casemate to be mounted, while only the gun itself would stick over the engine deck. The vehicle also had a somewhat better power-to-weight ratio, and, an obvious advantage, was introduced earlier, in 1944, in a context in which most tanks were still more lightly armored than what a French project proposed in late 1945, and which would likely have required months to a year to enter service, would have had to face were an armed conflict to break out in this time.
Thankfully, the project was never adopted, and was, very likely, never seriously considered for adoption, to begin with. The poor quality of the R35 hull, already very discussable by 1940 standards, was very obvious post-war, and even fixed gun, open-topped tank destroyers had generally proven to be inferior to medium tanks equipped with potent anti-armor weapons. As such, the R35 and S35-based projects were likely shelved very quickly after being proposed. Nothing is known of them outside of the schematics which were submitted by AMX.
Chasseur de Char de 76,2mm AMX sur châssis R35 (rear-facing proposal) specifications
|Dimensions (L-H-W)||6.22 x 1.85 x 2.17 m|
|Weight in battle order||11,046 kg|
|Engine||Renault 447, 4-cylinders gasoline producing 85 hp|
|Power-to-weight ratio||7.6 hp/ton|
|Armament||17-Pounder anti-tank gun|
|Ammunition stowage||42 rounds (12 in ready-racks, 30 in an ammunition locker)|
|Crew||Either 2 (driver, commander/gunner/loader) or 3 (driver, commander/gunner, loader)|
|Gun traverse||21° to each side|
|Gun elevation||+22 to -9°|