The Lorraine 37L or ("tank supply tractor 1937 L") is a light tracked armoured vehicle developed by the Lorraine company during the interwar period or interbellum, before the Second World War, to an April 1936 French Army requirement for a fully armoured munition and fuel supply carrier to be used by tank units for front line resupply. A prototype was built in 1937 and production started in 1939. In this period, two armoured personnel carriers and a tank destroyer project were also based on its chassis. Mainly equipping the larger mechanised units of the French Infantry arm, the type was extensively employed during the Battle of France in 1940. After the defeat of France, clandestine manufacture was continued in Vichy France, culminating in a small AFV production after the liberation and bringing the total production to about 630 in 1945. Germany used captured vehicles in their original role of carrier and later, finding the suspension system to be particularly reliable, rebuilt many into tank destroyers () of the Marder I type or into self-propelled artillery.
Development In 1934, the order was given to design a munition supply vehicle to increase the operational range of independent tank units. The same year, the Renault 36R was selected for further development; three hundred were ordered from 1938. However, this tractor was only partially armoured; on 17 April 1936, a new set of specifications was drafted for a fully armoured vehicle to deliver fuel and munitions to tanks fighting on the frontline.François Vauvillier, 2012, , Histoire de Guerre, Blindés & Matériel, p. 103
Early in 1937, the company finished a prototype. It was a lengthened version of a proposed replacement type for the 1931 model Renault UE Chenillette tracked infantry supply tractor. In February 1937, the matériel commission, the , was ordered to test the prototype and to complete an evaluation before 1 November 1937, even if testing had not been finished. The prototype was only presented on 9 July and tested until 4 August. It was equipped with a 2371 cc Delahaye four cylinder 124 F engine. Although the vehicle attained a maximum speed of , this dropped to an unacceptably low when an intended fuel trailer was attached. It was therefore returned to the factory and a more powerful Delahaye 135 engine and stronger clutch were fitted. This vehicle was tested between 22 September and 29 October and achieved the desired .
Production The commission approved the type during late 1937, being especially impressed by the rugged suspension system. It was decided in September 1939 to reserve the total production capacity of the suspension elements for the larger tractor. This implied that the shorter Lorraine replacement for the Renault UE, though also favoured over other candidates, would not be taken into production: an order of hundred made early 1939 was that month shifted towards the longer version.
In 1938, three orders were made: of 78, 100 and another 100 vehicles of the (TRC 37L); in 1939, before the war, a fourth order of 100 followed, and then a fifth of 74, to which was added the replacement order of 100 for a total of 552. The first vehicle was delivered by Lorraine on 11 January 1939; 212 had been delivered by 1 September 1939.
The ambitious plans made after the outbreak of war for the expansion of the number of armoured divisions meant that the Lorraine 37L orders had to be enlarged accordingly, bringing the total to 1,012. The intended initial production rate was fifty per month, to be expanded to seventy. To assist in the manufacture, a second assembly hall was erected by Fouga at Béziers, where it was hoped that it could produce at first twenty and later thirty vehicles per month.Steven J. Zaloga, 2014, French Tanks of World War II (1) — Infantry and Battle Tanks, New Vanguard 209, Osprey Publishing, p 42 In reality, this number was never attained; e.g. 20 were made in January and 32 by both companies in May 1940. By 26 May 1940, 432 vehicles had been delivered to the army from Lorraine and Fouga out of 440 produced. Production continued after that date and an estimated total of about 480 to 490 had been reached by 25 June 1940, the end of the Battle of France.
Description Derived from a project, the Lorraine 37 L was a rather small vehicle, just 1.57 metres wide. Space had been found by lengthening the chassis to 4.22 metres, making it rather oblong. Lacking a turret or superstructure its height was also not excessive at just 1.215 metres. The small dimensions combined with light armour — nine millimetres for the vertical riveted plates, six for the top and bottom and twelve for the cast rounded nose section — ensured a low weight: the basic TRC 37L weighs just 5.24 tonnes empty, the trailer adding 1.2 tonnes.
Given the vehicle's low weight, the suspension was quite robust and exceptionally reliable in comparison with other systems used on French armour of the time, which were either too complicated or too flimsy. Six large road wheels in three pairs of bogies gave a low ground pressure and good weight distribution. Each bogie was allowed a vertical movement in its entirety, sprung by an inverted leaf spring assembly located just below the upper track run, the three assemblies being placed between the four top rollers. The tracks were wide. The drive sprockets were in front and driven by a transmission in the nose of the vehicle. The two crew members, the driver on the left, sat in the forward compartment, the drive shaft between them. Entrance to the compartment was by two wide horizontal hatches, the upper hinging upwards, allowing the driver an unobstructed view if opened, the lower hinging downwards.
The centrally positioned engine compartment was separated by a bulkhead from the driver compartment in front of it. The external silencer was on the left of the vehicle under an armoured covering. All vehicles in the series were powered by a Delahaye Type 135 six-cylinder 3.556 litre engine developing at 2800 rpm, giving a maximum speed of and an average speed of . The wading capacity was 60 centimetres, a trench of 130 centimetres could be crossed and an incline of 50% climbed. There was a fuel supply of 114 litres, giving a range of . There were five forward gears and one rear gear.
At the back was an armoured ammunition bin; a load of 810 kilograms could be carried, bringing the weight to 6.05 tonnes. As with the Renault UE, the TRC 37L was supplied with a tracked, armoured trailer with two road wheels per side, mostly used to carry a 565-litre fuel tank to supply the tank units; total load capacity was 690 kg for a total for the combination of 1.5 tonnes, and a total weight of the trailer of 1890 kg. At 155 cm, the trailer was somewhat narrower than the main vehicle, and higher at 133 cm. It increased the combined length to 6.9 metres. The trailer also carried a Vulcano fuel pump and stowage boxes for lubrication oil, greases, water and assorted equipment to serve the tank maintenance teams.
The Lorraine 37Ls were painted in the standard army green, a rather greyish colour, over which a brown pattern of dark earth was sprayed.Steven J. Zaloga, 2014, French Tanks of World War II (1) — Infantry and Battle Tanks, New Vanguard 209, Osprey Publishing, p 41
Tactical function and operational history In 1939, the Lorraine 37 L was gradually introduced to the supply units of the tank battalions. This coincided with a change in tactical thinking about the use of armour. In the early thirties, French doctrine had favoured construction of ever deeper defensive belts to counter infantry infiltration tactics to defeat enemy attacks before they could develop into full-scale manoeuvre warfare, a field at which the French were aware of being less adept than their most likely adversary, Germany. Expecting any possible enemy to defend themselves likewise, the armour branch of the French Infantry became much preoccupied with the vexing problem of how to break through similar in-depth positions, emphasizing close cooperation with the foot soldier. Far less attention was paid to the next phase: the envelopment of the enemy forces.
The situation changed in the late thirties. Having at last built a considerable number of modern and well-armoured tanks, the Infantry became confident in its ability to break the enemy line, if sufficient artillery and air support was provided within a combined arms tactic. At the same time the political situation made it likely that large-scale offensives were needed to bring Germany to its knees. Though few officers advocated the creation of armoured divisions able to execute both the breakthrough and the strategic exploitation phase — these required trained personnel in numbers that simply would not be available — it was understood that the "manoeuvre mass" of tanks effecting the break would immediately have to envelop the defensive enemy position and defeat counterattacking enemy armour reserves, otherwise the momentum of the attack would be lost and the breach would not be kept open long enough for the motorised divisions and cavalry armoured divisions to be launched to quickly occupy and hold strategic key positions.
However, this posed a serious logistical problem: trucks would not be able to closely follow the tanks on the battlefield. The prescribed procedure for resupplying was for the tanks to return to their start positions to be refitted. While this had been practical in the previous war with its much slower tempo of operations, it was unacceptable in modern warfare. The tanks would have to be supplied in the field to continue their advance as soon as possible. Thus a tracked supply vehicle was needed that could overcome the expected poor terrain conditions, with many shell-craters and trenches, and it had to be armoured to protect against shell-fragments, given that the breakthrough sector would likely be in range of concentrated enemy artillery.
The type was provided to the armoured units of both the Infantry and the Cavalry. Each independent tank battalion of the Infantry, or , had an organic strength of twelve Lorraine tractors: four in the (supply platoon) of each of its three companies. The BCCs incorporated in the armoured divisions and equipped with the Char B1 or Char B1 bis had 27 TRC 37Ls: each of their three companies had six tractors in its supply platoon and furthermore a single tractor organic to each of its three tank platoons. This extra allotment was made to compensate for the large fuel consumption of these heavy tanks, that, apart from being simply bigger, had also a rather limited range. Each group of three tanks was in their case thus directly followed by its own fuel supply.
When, during the Battle of France, independent companies were formed, these, too, had their Lorraine tractors — an increased allotment of eight if a Char B1 bis unit, otherwise the standard allotment of four. However, the older FT 17 battalions only used fuel trucks. Likewise, the TRC 37L was not in common use in the colonies; however, when the 67e BCC, which was equipped with the Char D1, was brought over from Tunisia in June, it was provided with tractors. The motorised infantry divisions did not use the TRC 37L.
In the Cavalry, each squadron of twenty tanks had three Lorraine tractors, for a total of 24 for each mechanised light division. The AMR 35 or Panhard 178 units did not use the type, just trucks as its speed was considered insufficient. It was proposed to remedy this by fitting a stronger engine, bringing the speed to . The TRC 37L was also not present in the cavalry light divisions.