The Renault UE Chenillette was a light tracked armoured carrier and prime mover produced by France between 1932 and 1940.
In 1930 the French Infantry 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 in 1940 captured by Germany were used for a variety of purposes, including being armed with machine-guns, antitank-guns and rocket artillery.
Since 1922 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 after 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, as such an arms producer having no experience in vehicle development, had already started cooperation with the BritishVickers company to build a weapon carrier for its Brandt Modèle 1927 mortar; it proposed to produce 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 after some satisfactory testing for the smaller weapon carrier of the Vickers type. On 7 October it was decided to develop such a vehicle under the name of Type N. Orders for prototypes were in December 1930 made with three companies: Renault, Citroën and Brandt. Renault however indicated he had no intention to pay licence rights, unless the French state would fully compensate him; 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 again the tractor, 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 till 29 July. The commission noted that the cooling system failed and that there was no possibility to decouple 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 idea of production in France, Brandt delegated the task to build 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 on 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 on 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 velocity 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 hadn't 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 31of about 2600.
A Renault UE Chenillette de ravitaillement d'Infanterie Modèle 1931 R
in the Musée de l'Armée
. It has the straight mudguards, Restor
lights and typical "pig-tail" hooks of the early production vehicles
The Chenillette ("small tracked vehicle") or tracteur blindé ("armoured tractor") as Renault preferred to call it, is indeed a very small vehicle: just 280 centimetres long, 174 cm wide and having its highest point at 125 cm; the roof is only 103 cm high. Its cargo carrying capacity is rather limited. There is 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 is made easier by the possibility to tilt the bin; the back plate then hinges downwards, forming a slope on which cargo can slide to the ground. The main cargo is 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 can hold a load of about 600 kg — whereas the specification had asked for only 400 kg. The tracks can be removed for road transport; there are two road wheels per side.
The bin forms the back compartment of the vehicle; the larger front compartment is 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 are placed in front of the engine. These mechanical parts are 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 its seat, together having a total capacity of 56 litres, allowing for a range of a hundred kilometres. The exhaust pipe runs 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 height of the vehicle it has been made impossible for the crew members to retract their heads under the roof. To protect these vital parts two hemispherical armoured hoods (calottes) have been fitted. These have vision slits but to improve the field of vision the front section of these hoods can like a visor be pivoted backwards over the back section. As otherwise a bar between the roof and the glacis would have hindered entrance, the forward hinging glacis hatches have 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 is thus available. An interesting feature of the vehicle is the internal communication system used. When the hoods are closed, the two crewmen, separated by the engine between them, cannot directly communicate; neither internal nor external radio communications are possible, as there are simply no radio sets fitted. A system of white, blue, green and red lights, that can be made to shine continuously or flicker, is 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 resembles the Vickers type. There are 18.4 cm wide tracks with 131 small links and three bogies per side, sprung by small leaf springs, carry 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 are two return rollers. In all the suspension system is flimsy and vulnerable. This is compensated by limiting the official maximum speed to thirty kilometres per hour, 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 36 km/h was attainable. This also reduces the chance of accidents while towing the trailer; fully loaded the road speed is reduced to 25 km/h, the cross-country speed to ten km/h. The wading capacity is thirty centimetres; the trench crossing capacity 120 centimetres. The turning circle is three metres; a slope of 50% can be climbed.
The value of the Chenillette as an armoured fighting vehicle was limited. In French service, the Modèle 31 carried no armament, although some later vehicles had attachment points for a removable AA-machine-gun to be fitted — but this had to be operated from outside the vehicle in an awkward crouched position due to its low height. For the crew to use personal weapons through the hatches while sitting inside the hull was highly impractical. Consideration had been given to arming it with a machine-gun, but the Direction de l'Infanterie feared that if such a weapon were mounted, the UE would be misused as a light tank rather than being dedicated to its correct tactical resupply role. Likewise the armour protection was minimal. The vertical plates had a thickness of nine millimetres, the other plates, all riveted, were six millimetres thick, just enough to stop normal rifle bullets and shell fragments.
Development of the Renault UE2
Renault UE2 with Renault UK trailer at the Musée des Blindés at Saumur; the upward bend of the front mudguard would make it be described as a Modèle 37; the internal mechanical parts are those of a late production vehicle.
From 1935, in reaction to the German rearmament, the French Infantry embarked on a major expansion and modernisation programme. Part of this was the project to replace the Chenillette Modèle 31 with an improved type, which however should remain within the weight limit of the earlier vehicle or 2.6 metric tons. Interest from the side of the French industry was high and during 1937 five companies proposed prototypes: Lorraine, Hotchkiss, Fouga, Berliet and Renault.