The Hotchkiss H35 or was a French cavalry tank developed prior to World War II. Despite having been designed from 1933 as a rather slow but well-armoured light infantry support tank, the type was initially rejected by the French Infantry because steering proved difficult during cross-country use, and was instead adopted in 1936 by the French Cavalry arm.
From 1938 an improved version was produced with a more powerful engine, the Char léger modèle 1935 H modifié 39, which from 1940 was also fitted with a longer, more powerful 37 mm gun. It was intended to make this improved variant the standard light tank, with at least four thousand produced to equip new armoured divisions of both the Cavalry and the Infantry arms, but due to the defeat of France in June 1940, total production of both subtypes was limited to about 1200 vehicles.
For the remainder of the war Germany and its allies used captured Hotchkiss tanks in several modifications.
Development In 1926, it had been decided to provide armour support to the regular infantry divisions by creating autonomous tank battalions equipped with a light and cheap infantry tank, a char d'accompagnement. For this role at first the Char D1 was developed which type however, proved to be neither particularly light nor cheap. In 1933, the Hotchkiss company under its own initiative presented a plan to produce a lighter design—this was made possible by the application of a new technology to produce cast steel sections to construct an entire hull. On 30 June 1933, this proposal was approved by the Conseil Consultatif de l'Armement. On 2 August 1933 the specifications were issued: a weight of and armour protection all around. Three prototypes were ordered from Hotchkiss, but the French industry as a whole was also invited to provide alternative proposals for a nouveau char léger.François Vauvillier, 2011, "Gamelin impose le Hotchkiss à la Cavalerie", Histoire de Guerre, Blindés & Matériel, 98: 6–17
This allowed the Renault company to beat Hotchkiss in delivering the first prototype, which later was developed into the Renault R35. On 18 January 1935, the first Hotchkiss prototype, not yet made of armour steel, was presented to the Commission d'Expérience du Matériel Automobile (CEMA) at Vincennes; it was a machine gun-armed tankette without turret. It was tested until 4 March 1935, when it was replaced by the second identical prototype to be tested until 6 May. Both had to be rejected because new specifications had been made on 21 June 1934 that increased the desired armour thickness to . On 27 June 1935 the commission approved the type on the provision that the necessary changes would be made. On 19 August the third prototype was delivered, equipped with a cast APX turret and featuring a redesigned hull; it was tested until 20 September and accepted.
On 6 November 1935 a first order was made for 200 vehicles. Though it should have been completed between July 1936 and July 1937, the first production vehicle was in fact delivered on 12 September 1936. A first additional order had already been made of 92 on 7 September 1936, to be completed in November 1937. A third one of 108 vehicles followed on 23 January 1937, to be completed in September 1938. These vehicles had the series number 40000 to 40400. By 1 January 1937 132 hulls had been produced. None of these had at that date been fitted with a turret.
Rejection by the Infantry and adoption by the Cavalry
The first series vehicle was again extensively and intensively tested until 4 December 1936. The testing soon showed that its cross-country handling qualities were unacceptably poor; it proved impossible to safely steer the vehicle on an uneven surface, posing an extreme danger to nearby friendly infantry. The Infantry therefore initially rejected any further procurement. Eventually, in 1937, it decided to accept only the last hundred tanks to equip just two battalions with the type: the 13e and 38e Bataillon de Chars de Combat.
For political reasons however, stopping production of the tank was unacceptable. As a result, the first three hundred vehicles of the production run were offered to the Cavalry, which was forced to accept them because it would not have been granted a budget for other tanks anyway. As the cavalry units would be making more use of the road network and of mounted infantry, its cross-country handling problem was of less consequence. The H35 was, at , also somewhat faster than the Renault R35, which was capable of , although in practice its average speed was lower than that of the R 35 because of its inferior gear box.
Description
The Hotchkiss H35 was long, wide and tall and weighing . The hull consisted of six cast armour sections, bolted together: the engine deck, the fighting compartment, the front of the hull, the back of the hull and two longitudinal sections left and right forming the bottom. The hull was made water-tight by cementing these sections together with Aslic, a product based on tar mixed with lime. The casting allowed for sloped armour, avoiding shot traps, to optimise the chance of deflection but the protection levels did not satisfy the Infantry. Maximum armour thickness was not the specified but . There were persistent quality problems, worsened by the fact that many subcontractors had to be used: at first the armour was made much too soft; when hardness was increased it became brittle and full of bubbles and hence weak spots.
There was a crew of two. The driver sat at the right front, behind a large cast double hatch and next to the combined gearbox and steering unit.AFV Profile No. 36 p. 18 Behind him was a round escape hatch in the bottom of the hull. Driving the vehicle was very hard work. The Hotchkiss lacked the Cleveland differential ("Cletrac") of its Renault competitor, and it responded unpredictably to changes of direction. The brakes could not sufficiently compensate for this, being too weak, especially when driving down-slope. No less troublesome was the gearbox: it was difficult to engage the highest fifth gear and so the theoretical top speed of was rarely reached. There was one reverse gear. The inevitable rough handling of the tank by the driver resulted in much wear and tear. Mechanical reliability was poor.
The suspension consisted of three bogies per side—each formed of two bell cranks arranged as "scissors" with springs at the top. Each bogie carried two rubber-rimmed wheels.AFV Profile No 36 p. 20 The first ten production vehicles, which can be considered as forming a separate pre-series, had curved bogie sides; in later vehicles the bogies had straight sides. The bogies superficially resembled the R35 type, but used horizontal helical springs instead of rubber cylinders. The sprocket was at the front, the idler—which itself was sprung to automatically control tension—at the rear. There were two top rollers.
The rear of the hull formed an engine room, separated from the fighting compartment by a fireproof bulkhead. The tank was powered by a 78 hp six-cylinder 86 x 100 3485 cc engine which was on the left of the engine compartment. A 160-litre fuel tank on the right, combined with a twenty litres reserve reservoir, gave a range of or eight hours on a varied terrain. The engine was cooled by a centrifugal pump. Also a cooling fan drew air through the radiator and was also expected to cool the fuel tank.AFV Profile No. 36 p. 16 The trench-crossing capacity was , the wading capacity . On hard soil a slope of 75 percent could be climbed, on soft soil of 55 percent. Maximum tilt was 50 percent. Ground clearance was .
The APX-R turret was the same standard type as used on the R35 and R40 tanks, made of cast steel and armed with the short 37 mm SA 18 gun, which had a maximum armour penetration of only . Traverse of the turret was with a handwheel. The commander sat in a saddle suspended from the turret.
The tank carried about 100 rounds for the gun, and 2,400 rounds for the coaxial 7.5 mm Reibel machine gun – the 37 mm ammunition was racked on the left hand side of the hull, the 7.5 mm ammunition on the right side in fifteen circular magazines with 150 rounds each; with usually an additional magazine on the machine-gun itself. The turret had a rotating cupola with a PPL RX 180 P visor but there was no hatch in the cupola though its top could be lifted a bit for better ventilation. Apart from the cupola there were protected vision devices, a binocular periscope and diascopes, to the front beside the gun and to each side.AFV Profile No. 36 For access there was a hatch at the back of the turret. When opened, the commander could sit on it for better observation, but this left him very vulnerable and slow to reach the gun. The alternative was to fight closed-up, observing through the vertical slits or the visor of the hatchless cupola. The Cavalry liked neither this arrangement nor the weak gun. The latter problem was lessened by enlarging the breech so that special rounds with a larger charge could be used. This increased muzzle velocity to about and maximum penetration to about . Only a small number of the tanks, and limited to the Cavalry, were modified however, because it greatly increased barrel wear. In the spring of 1940 the original diascopes of the Chrétien type were gradually replaced with episcopes, offering more protection.
The Char léger modèle 1935 H modifié 39
As the Cavalry wanted an even higher top speed, it was decided to bring to fruition experiments already conducted from October 1936 to install a more powerful engine. A new prototype was built in 1937, with a 120 hp engine instead of the 78 hp one. The hull was enlarged, giving it a higher almost level engine deck, to accommodate it. The track and the suspension elements were improved, raising the weight to . This improved type was faster, with a top speed of , but also proved much easier to drive. As this removed one of the objections of the Infantry, it was first presented to the Commission d'Expérimentations de l'Infanterie on 31 January 1939 to see whether the original negative decision could be changed. The commission indeed accepted the type, the Char léger modèle 1935 H modifié 39; and it was decided on 18 February to let it succeed the original version from the 401st vehicle onwards, which was just as well as both in 1937 and 1938 an order had been made of two hundred vehicles and production had already started, the total orders of the improved type thereafter being expanded to nine hundred. The factory identifier however, was Char léger Hotchkiss modèle 38 série D, its predecessor having been the série B. The factory designation has caused much confusion; this was still officially the same tank as the H35, only in a later variant; even at the time, many began to refer to it as the 38 H or the 39 H.
The new subtype differed from the original one in having a raised and more angular engine deck (in later production vehicles with crosswise instead of longitudinal ventilation slits on the right side); a range decreased to ; closed idler wheels; tracks wider at ; metal instead of rubber wheel treads; a new exhaust silencer directed to the back and larger, more reliable and effective ventilators.