The Renault UE Chenillette is a light tracked armoured carrier and prime mover produced by France between 1932 and 1940.
In 1930, the Commission de Vincennes decided to develop a light armoured vehicle able to tow and supply small cannon and mortars. In 1931, the Renault company was given the contract for production of its Renault UE, combined with the Renault UK trailer. In 1937, from a number of competitors, the Renault UE2 was chosen as an improved type for large-scale production. Of both types combined, over five thousand were built, including licence production in Romania, and they were part of the standard equipment of all French infantry divisions. Most Renault UE vehicles in French service were unarmed; those captured by Germany in 1940 were used for a variety of purposes, including being armed with machine-guns, anti-tank guns and rocket artillery.
Development From 1922 onwards, it had been the policy of the French Infantry to mechanise as many units as possible. Budgetary restraints made it unrealistic to fully equip them with armoured personnel carriers; but the mass production of smaller armoured vehicles in the roles of munition and supply carrier and weapon carrier for machine guns and mortars seemed feasible. For some years, the decision to produce these types was delayed. But, when in 1929 an experiment with an automotive trailer guided by a walking soldier had completely failed, it was decided to develop a single vehicle for both missions. In the spring of 1930, several possibilities were considered, among them a standard 3.5-ton truck and the existing Citroën-Kégresse half-tracks. Brandt, an arms producer having no experience in vehicle development, had already started cooperation with the British Vickers company to build a weapon carrier for its Brandt Modèle 1927 mortar; it proposed producing the British Carden-Loyd Mark VI carrier under licence and presented a smaller and a larger vehicle, together with matching trailers, imported from Britain, for the supply and weapon carrier task respectively. On 24 July 1930, the Commission de Vincennes rejected the truck and half-tracks as being too heavy and opted for the smaller weapon carrier of the Vickers type after limited, though satisfactory, testing. On 7 October, development of such a vehicle under the name of Type N was decided upon. Orders for prototypes were placed in December 1930 with three companies: Renault, Citroën and Brandt. However, Renault indicated they had no intention to pay licence rights, unless the French state fully compensated them; the three companies were thus invited to build a "similar" vehicle, not an exact copy. The orders were for armoured tractors and matching tracked trailers and for a heavier trailer to carry the tractor itself, to be pulled by a truck while the smaller trailer trailed behind.
In the summer of 1931, the prototypes were ready for trials. Citroën had received orders for six tractor prototypes: three fully tracked vehicles and three of the half-track type. The first prototype to be ready, not at all resembling the Carden-Loyd carrier, was in the form of a very small half-track fitted with a Kégresse track and manned by only a driver protected by an armoured hood with vision slits, sitting on the left side of the vehicle, with the engine to his right. Only the nose of the vehicle was armoured. It was presented to the Commission de Vincennes on 24 July 1931 and tested until 29 July. The commission noted that the cooling system failed and that there was no possibility of decoupling the trailer from inside the driver's cabin. On 31 July, the other two half-tracks were delivered together with the first two trailers. The matériel was rejected as being too vulnerable. Citroën discontinued the development of the fully tracked vehicles but rebuilt one of the half-tracks prototypes into the prototype of the larger AMR Citroën Kégresse P 28 half-track, fifty of which would be built.
On 10 and 17 December 1930, Brandt had obtained an order for six complete sets: tractor, trailer and tractor-carrying trailer. To honour its commitments to Vickers, it let the trailers and one tractor be built in Britain. To conform to the requirement for production in France, Brandt delegated the task of building a new tractor type to the Latil company, as it had too little experience itself. The Latil prototype, presented on 7 August 1931, was very much along the lines of the British type and strongly resembled the later Universal Carrier: fully tracked and with most of the vehicle covered by an open rectangular superstructure to ensure as large a carrying capacity as possible. Only a small driver's and engine section at the front was armoured on top. On 17 July, the commission considered the type ready for troop trials.
The first prototype to be ready was that of Renault, that also had received orders for six sets. It was tested between 15 and 23 April 1930. Certain defects were found and remedied, after which the prototype was again tested from 3 June. A second prototype, fitted with a rubber track, was tested between 28 April and 12 May. This other track type was shown to be too weak. The project had as factory designation Renault UE, a chronological letter code without further meaning; the smaller trailer was the Renault UK. The Vickers suspension with double track guides was imitated. For Renault this new suspension type, that he patented despite its obvious Vickers ancestry, offered the solution for severe problems he had experienced trying to adapt his existing suspension models, using single track guides, to a high-speed vehicle without increasing the chance that the track would be thrown at higher speeds. Renault hoped to further develop the UE into a light tank by adding a turret; accordingly, the hull resembled a tank chassis rather than a dedicated supply vehicle.
In October 1931, the Conseil Consultatif de l'Armement, under strong pressure by the Infantry to reach a quick decision, chose the Renault vehicle for production, even though the trial process had not been completed. On 9 December, an order of fifty was made for the Chenillette de ravitaillement d'Infanterie Modèle 1931 R. On 26 March 1932, a preseries of fifty tractor-carrying trailers was ordered, the first was delivered in June. Further orders followed, mass-production commencing in the second half of 1934. The series vehicles differed from the first in having a towing sign plate fitted on the top, new towing hooks and an elongated stowage box on the left side. Orders reached a total of 793 on 1 January 1936 and of about 1,200 by June 1936 — 700 of which had been delivered by June 1936, 920 by October 1936, 976 on 1 January 1937. In December 1936, the military branch of Renault was nationalised as the AMX company, which continued production to a total of about 2,200, later joined by Berliet, which would build another 100, and Fouga, which would produce 300 for a grand total for the Modèle 31 of about 2,600.
Description
The Chenillette ("small tracked vehicle") or tracteur blindé ("armoured tractor") as Renault preferred to call it, was a very small vehicle: just 280 centimetres long, 174 cm wide and having its highest point at 125 cm; the roof was only 103 cm high. Its cargo carrying capacity was rather limited. There was a rectangular armoured bin at the back, 145 cm long (its length corresponds to the width of the vehicle as a whole), 60 cm wide and 36 cm high, able to hold a load of about 350 kg (lower than the original specification of 500 kg); unloading was made easier by the possibility of tilting the bin; the back plate then hinged downwards, forming a slope on which cargo could slide to the ground. The main cargo was carried by the tracked trailer, a close copy of the British type, with a length of its bin of again 145 cm, a width of 110 cm and a height of 35 cm; weighing itself 775 kg, it could hold a load of about 600 kg — whereas the specification had asked for only 400 kg. The tracks could be removed for road transport; there were two road wheels per side.
The bin forms the back compartment of the vehicle; the larger front compartment was for the crew and engine. The four-cylinder 38 hp engine is positioned in the centre, with the driver to its left and the commander to its right. The gear box (six speeds forward, two reverse), differential and transmission were placed in front of the engine. These mechanical parts were placed under two projections on the otherwise very steeply sloped armour of the glacis; these can be retracted for maintenance of the mechanical parts. Each crew member, sitting below a hatch that is the only way of entrance or exit, has a fuel tank behind their seat, together having a total capacity of 56 litres, allowing for a range of a . The exhaust pipe ran in front of the commander to the right ending in a silencer on the right side of the vehicle; in later production vehicles an armoured cover was added. As it tended to overheat a later variant of this cover had cooling slits.
To reduce the vehicle's height, it was made impossible for the crew members to retract their heads under the roof. To protect these vital parts, two hemispherical armoured hoods (calottes) were fitted. These had vision slits but, to improve the field of vision, the front section of these hoods could be pivoted backwards over the back section like a visor. As otherwise a bar between the roof and the glacis would have hindered entrance, the forward hinging glacis hatches had an extension forming the roof section that fits around the front part of the hood; if the hood is retracted and the hatch opened, a larger entry space was thus available. An interesting feature of the vehicle was the internal communication system used. When the hoods were closed, the two crewmen, separated by the engine between them, could not directly communicate; neither internal nor external radio communications were possible, as there were no radio sets fitted. A system of white, blue, green and red lights, that could be made to shine continuously or flicker, was used by the commander to direct the driver when buttoned up, based on a predetermined signal code: Forward: continuous white light. To the left: continuous blue light. To the right: continuous green light. Backwards: flickering white light. Slow down: flickering red light. Stop: continuous red light. Decouple the trailer: alternating white and red light. Tilt the bin: alternating green and white light.
The suspension system closely resembled the Vickers type. There were 18.4 cm wide tracks with 131 small links and three bogies per side, sprung by small leaf springs, each carrying each two small road wheels. The prototype had an armoured plate protecting this assembly, but it was omitted on the production vehicles to save weight, leaving only two elongated beams to brace the whole. Likewise, the sprocket was simplified: the prototype's had been a closed disk, the production type had six circular holes; later vehicles were fitted with a wheel with six spokes. There were two return rollers. In all the suspension system was flimsy and vulnerable. This was compensated by limiting the official maximum speed to , although the combination of a weight of just 2.64 metric tons with an engine power of 38 hp would allow for a higher speed; during testing was attained. This also reduced the chance of accidents while towing the trailer; fully loaded the road speed was reduced to , the cross-country speed to . The wading depth and the trench crossing depth . The turning circle was and a slope of 50% could be climbed.