Char R30

Dimensions:
Weight: 9.8 tons
Length: 4.10 meters
Width: 2.14 meters
Height: 2.18 meters

Automotive systems:
Suspension;
270mm wide tracks
x6 per side 400mm diameter roadwheels
84hp V-4 petrol engine

Automotive effects:
Speed: 25 kilometers per hour maximum
Autonomy: 150 kilometers
Transmission gears: 5 forward, 1 reverse

Protection:
30mm all around (later upgraded to 40mm)

Detailed armor thickness (mm) :
Turret Front : 30mm/5° and 28° + gun mantlet
Turret Sides : 30mm/25°
Turret Rear : 30mm/30° (rear hatch is 30mm thick)
Turret Top : 20mm/90°
Copula : 30mm/round
Hull Front, Upper : 30mm/30° (driver’s hatch is 30mm/30°)
Hull Front, Lower : 30mm/50°
Hull Sides, Upper : 30mm/0°
Hull Sides, Lower : 30mm/0°
Hull Rear : 30mm/25°
Hull Top : 20mm/90°
Hull Bottom : 10mm/90°

Armament:
x1 47mm SA 34 (or 47mm SA 35) w/ 90 or 78 rounds respectively
x1 7.5mm Reibel machine gun with 2,400 rounds of ammunition

Crew:
2, commander/gunner/loader, driver

Overview

 The R30 was created to form the French basic light infantry tank in the 1930s, as a result of the perceived failings of the D1 during the brief War of the Ruhr against Germany. During the late 1920s, France had thought of the D1 as providing a new light infantry tank, replacing the Renault FTs. However, war experience in Germany also highlighted some of the failings of the very light infantry tanks. As a result, the R30 of Renault could be viewed as something of a cross between the D1 and the light infantry tanks, aiming to combine the cheapness of the latter with some of the capabilities of the former. In this it mostly succeeded, although some of the drawbacks of the design would be extensively attacked later on.

Origin

 France had in its possession after the Great War the largest tank fleet in the world, principally composed of the Renault FT. It had an operational capacity of over a thousand tanks in readiness, and a reserve of thousands more. However, there were as the decade wore on, several problems became clear. The Renault FTs were inadequately mobile even for the role of an infantry tank, had inadequate armor in the face of improving anti-tank guns, insufficient operational range, and were becoming increasingly run down. There had to be some sort of tank to evenutally replace them.

 Initially this was supposed to be the Char D1, a light and cheap infantry tank which could be procured in large numbers. The D1 however, experienced a number of problems. It was not very cheap, and its weight, which reached 14 tons, meant that it was not light either. During the experimental action in the Rhine War, there was insufficient reliability, and the turret had very poor design (although this was expected to be fixed) and wasn't even available yet, requiring Renault FT turrets to be used instead. The D1 was almost rejected out of hand after this, and it took a massive modernization program to improve on its defects.

 This meant that there was no available light infantry tank to serve the French army. With the potential of an ongoing and lengthy Rhine War as reports of the D1's poor standing were trickling back, this was unacceptable. As a result, France made arrangements with Renault and other manufacturers for emergency plans for a new light tank design. This would be what would become the R30. Built with the greatest of haste, ultimately Renault's design would be chosen, and it would become the standard infantry tank of the French Army.

General characteristics

 R30s were thoroughly conventional vehicles at the time of their introduction, choosing tried and tested technology instead of newer advances that might endanger it. It was designed out of riveted armor material in the R30 variants, although the R33 variants changed this to three cast hull sections instead. The turret was cast as well. The vehicle under its initial design had a weight of 9.8 tons - heavier than hoped but still within acceptable parameters - a 1,030mm turret ring being used to mount the turret, while the vehicle's length was 4.10 meters, width was 2.14 meters. Height was 2.18 meters. The front armor is sloped, with a heavily sloped frontal section and a less sloped driver's position, while the turret is five sided and with a frontal mantlet for the gun. There are two tracks, with six road wheels of 400mm diameter per each side, and which have a width of 200mm for each track.

Armament

 One feature that on the D1 was appreciated was the improved 47mm cannon. As compared to the 37mm guns previously fitted to French vehicles such as the SA 18, the SA 34 had an HE capacity of 142 compared to 30 grams of HE. This was combined with much superior AP performance, which meant that the 47mm was a dramatically better gun in the tasks of dealing with enemy positions, troops, and armor. As a result, its placement on the vehicle was desirable. This did however, require the expansion of the vehicle's turret ring, which was a part in its increased size. Its turret ring was roughly the same size as the new Char B1, with the hope that the two vehicles could later standardize on the same turret. The 47mm SA 34 L/30 fires shells that are 47x139mm and weigh 1.48 kilograms for APHE having a muzzle velocity of 450 m/s and a HE capacity of 50 grams, while HE weighs 1.41 kilograms with an HE capacity of 142 grams. There is a theoretical rate of fire of 15 rounds per minute, and a practical AT range of 400 meters. At this range it has a penetration of 25mm /30 degrees. There are a total of 90 rounds carried for the 47mm gun, which are generally divided between 30 AP rounds and 60 HE rounds, although this can vary depending on expected target to face - with those assigned to infantry support often having only a doze or so AP rounds.

 In addition, there is an onboard coaxial machine gun mounted next to the gun, of 7.5mm - being of the new Reibel machine gun type. There was consideration of mounting another 7.5mm machine gun for the use of the driver, but this was rejected due to weakening the frontal armor, increasing complexity, and taxing the driver as well. The machine gun that it does have has 2,400 rounds of ammunition. Fired rounds go through a chute to the floor of the vehicle for later disposal. It is possible to dismount the 7.5mm machine gun and use it as an AA mount on the rear of the turret, with in this position the turret itself facing to the rear.

 Both guns have depression/elevation of -15/20 degrees respectively, giving very good angles for this. They are also eqipped with 5 degrees of traverse to the left and right respectively, to enable the guns to be aimed without the need to move the turret. Given that the turret is hand cranked by the commander, doing so is important for the vehicle to have sufficient capability for engagement of moving targets.

Protection

 A major reason behind the replacement of the Renault FT was that it had inadequate armor to face improving anti-tank weaponry. During the R30 design process, an armor  of 30mm was specified instead of the Renault FT's 16mm and 22mm. This was combined with effective armor sloping, further improving the capability of it to deflect enemy shells. Turret armor is 30mm on all sides, with an additional mantlet of 20mm. The cupola has armor of 30mm as well, and it has four vision slits, as well as a hinged top hatch which can be opened by the commander. There is a rear hatch on the turret with armor of 30mm as well. For the hull, frontal armor is 30mm at 30 degrees at the top, and 30mm at 60 degrees for the lower part. The hull and turret tops are both 20mm, while the hull bottom is 12mm. There is a fireproof bulkhead between the engine and the crew/fighting compartment of the vehicle.

Sights

 There are a number of sighting mechanisms on the vehicle. It has a cupola, which is of course for the usage of the commander. This has four vision slits of 7mmx150mm width and length respectively, which also has 15mm armored shutters to be closed when not in use. It can also hinge upwards and be opened, ine a first for a French tank. For use otherwise, the commander has an L.713 sight for the 47mm gun, which is x4 magnification, and with a field of view of 11.25 degrees. He also has 3 diascopes with a 30 degree field of vision. A slit is provided in the rear turret hatch. In the hull meanwhile, there is an episcope with a field of vision of 30 degrees for the driver, as well as two vision slits.

[b]Mobility[/b]

 Being designed to be an infantry support tank, the R30 is not excessively fast. It is however, more mobile than the Renault FT and other proceeding vehicles, and is reasonably capable of travel, as well as crossing obstacles. The vehicle has the normal twin tracks, which have six road wheels each, each of a diameter of 400mm. Tracks themselves have a diameter of 270mm. These are each supported in twin boogie arrangements. It has a frontal mounted transmission with the transmission system passing from the rear engine to the frontal system. Although this separation increases height, it also makes it much easier to conduct maintenance, a vital aspect for a light, mass produced tank. The vehicle is equipped with a clevelent differential system, which helps to make steering easier for the driver. It has five gears forward, and one reverse gear.

 An 84 horsepower engine of the Renault V-4 was provided, which provides for sufficient horsepower for the vehicle to be able to executive most of the preferred mobility options. Given the vehicle's general weight of 9.8 tons this means that it has a power to weight ratio of 8.57 horsepower per ton, mostly sufficient for its operations. The engine is located to the left side of the compartment, while the right side holds fuel. It can cross a trench of 1.9 meters, ascend slopes up to 55 degrees degrees, and ford 85cm of water. It can also clear obstacles of 1 meter. The vehicle has an operational range of 150 kilometers. Waterproofing of the hull was achieved through the spreading of an "aslic" tar material, helping it ford rivers and keep water out in rains and other operations.

Ergonomics and Crew

 Each vehicle has a crew of 2 men, these being the commander/gunner/loader, and the driver. Having one man for the entire functions of offensive action and command naturally stresses them, but for the light tank which wouldn't be used as commonly for the purposes of engagement of enemy tanks it was viewed as mostly reasonable. The commander is located in the turret, and he accesses this through a hatch to the rear of the turret. During combat he tends to stand, although he also has a chair to sit on.  The driver accesses his compartment through a hatch which can be opened up for him to enter the vehicle, in front of his compartment.

 There are no radios equipped in general service, although some specialized units can be equipped with them as necessary. A potential long term plan also exists to provide platoon leaders with radios.

Variants

 Since it became from the start the primary French tank for the 1930s, the R30 developed a wide array of variants for it. A number are listed below.

R30-C
 The R30-C, or R30-Cavalerie, is a modification of the R30 which was produced for the cavalry. The main change for it from the standard R30 is that the sloping rear engine section was expanded to that the rear hull was almost level, enabling a more powerful 150 horsepower engine to be fitted, dramatically improving mobility from the R30's 8.5 horsepower per ton to nearly 15 horsepower per ton. In addition, range grew slightly to 170 kilometers. Weight went up to 10.2 tons though. It was developed in 1934.

R30 Modifie 1933
 After the introduction into service of the R30, there were a number of problems exposed on the initial design. A primary one in 1933 was that of the armor, which was both judged as being inappropriately thin, but also poorly constructed and riveted instead of cast. The 1933 modification improved the 30mm armor to 40mm, and also casted the armor out of three components instead of being riveted, improving protection. Weight grew to 12.5 tons as a result of this change. It also added 8mm armor screens protecting the running gear.

R30 Modifie 1935
 The Modifie 1935 represented the high point of the R30 design under its original intent. It dramatically changed around the suspension, which was less effective than otherwise desired, instead choosing a system with 12 small road wheels per each side, which helped to improve reliability. It also changed around aspects of driver's controls. There was an improvement in armament, with the adoption of the 47mm SA 35 gun instead of the 47mm SA 34, although this did drop the number of rounds carried slightly to 78 rounds. Tracks also were improved to 280mm in width from 270mm, further decreasing ground pressure. Episcopes were also fitted instead of diascopes, improving protection of systems of vision. A program to give every platoon leader a radio was also initiated.

R30 CA

 One of the most innovative developments of the French Army, the R30 CA was an assault gun with a 75mm ABS SA 35 howitzer mounted on top of the vehicle to replace the former turret. This provided an enclosed superstructure mounting the howitzer, with the vehicle as a whole having 30mm armor (it appeared in 1932, due to the realization that the Char B could not feasible equip enough units, and since the R30's 47mm gun was not sufficient for some of the tasks demanded of it). As a result, the 75mm howitzer gave the French infantry an assault gun capable of dealing with enemy infantry in the field, as well as hardened positions and anti-tank guns. There began a program to equip a company of these guns (10 guns) to each infantry division as part of the autonomous tank battalions.