Renault UE Chenillette - Development

Development

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 British Vickers 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 31 of about 2600.