In 1930, at a time the Char D1 had not even entered production, the Renault company agreed to build a better armoured version called the Char D2. By using welded armour plate instead of the dated riveted design of the D1 this would be lighter than a simple version of the D1 made with thicker plating. The tank should be able to serve as an alternative in the role of battle tank for the heavy Char B1, should the latter be forbidden by treaty. The failure of the armament limitation talks resulted in a severe reduction of the projected manufacture, now in the form of an interim tank. Organisational difficulties with Renault caused the actual production of a first series of fifty to be delayed to the years 1936 and 1937. A second series of fifty was ordered in 1938, despite indications that the type was mechanically unreliable, as a possible cheaper addition to the expensive Char B1, to be able to raise more armoured divisions of the Infantry Arm. Due to Renault's financial problems, this second, partially improved version, was only realised in early 1940, bringing total production to a hundred.
The three prototypes were, among others, fitted with turrets of theRenault FT 17 during a mock-up. The production models of the first series had the APX-1 turret, armed with a short 47mm SA34 tank gun. The second series used the much more powerful 47mm SA35 tank gun; from March 1940 this was retrofitted to a number of the older vehicles, despite a parallel project to rebuild them as flamethrower tanks.
In 1937 the type equipped one tank battalion, which was considered an elite unit, as part of Charles de Gaulle's regiment. It was well-trained in the use of advanced tactics, including the use of radio-sets. In 1940 the effectiveness of this unit had much diminished, because of the worn-out state of its tanks, aggravated by the decision to raise three autonomous tank companies with the new vehicles, even though insufficient trained crews were available. Nevertheless the Char D2 units fought tenaciously during the Battle of France, losing most of their tanks to mechanical breakdown instead of enemy action.
Development
At the same time the Char D1 was ordered, a plan was made to develop a more modern tank. The Char D1 had already departed from the pure infantry support concept and evolved from a light into a medium tank, capable of fighting enemy armour; this made it the obvious candidate to be quickly changed into a lighter alternative for the Char B1 battle tank, needed because the latter type was in danger of being forbidden by an expected armaments limitation treaty under the auspices of the League of Nations, imposing an upper weight limit of twenty metric tonnes for armoured fighting vehicles.
The Direction de l'Infanterie proposed on 23 January 1930, in a letter to the ministry of defence, to build a better armoured tank, using 40 mm plate, that nevertheless would be swifter at 22 km/h by fitting a 120 hp engine. The weight however should rise only from 14 to 15.5 metric tonnes, made possible by using welded instead of riveted armour plate. On 14 April the plan was approved and in May Louis Renault was contacted, who agreed to develop this type as the Char D2, together with a colonial tank, theChar D3, which would closely resemble its sister project.
To introduce the new welding technique entailed hiring foreign experts, which was very expensive. Renault insisted that the costs would be paid in advance by the French Army, which however had no corresponding budget available. On 8 December 1931 the deadlock was broken by a new agreement: Renault would first build a prototype with a riveted hull, the Renault UZ, which was delivered in April 1932. First the type was tested in Rueil; in May 1933 field tests were carried out by 503e RCC. The type was accepted for production, which decision was affirmed by the Conseil Consultatif de l'Armement on 12 December 1933.
At that moment however, Germany had just left the League of Nations altogether, making the limitation talks irrelevant, from which then France retired also. Existing plans to produce 750 Char D2s, 150 per year for the period 1935-1939, (six hundred to equip twelve battalions and 150 as a matériel reserve) were immediately reduced. On 14 January 1934 the High Command confirmed only the plan of a first production order of fifty. All these decisions were taken on the basis of experience gained with the riveted prototype, though it was well understood that from it no firm conclusions could be drawn on the quality of the intended welded type.
Meanwhile two welded prototypes had been ordered in December 1932. These were finished in August 1933, but only delivered in November. From December 1934 till the summer of 1935 the Commission de Vincennes used the three available prototypes to test different engine configurations. The riveted hull was equipped with a 120 hp petrol engine; the other two with diesel engines. These were rejected in favour of the petrol engine even though its combination with the intended welded hull had not yet been tested.
Nevertheless on 29 December 1934 the order of fifty hulls was granted to Renault, at a price of 410,000 French Francs per piece. The turrets were produced separately. First the ST3 turret (Schneider Tourelle 3) had been tested in 1933; then it was considered to use the ST2, then seen as a possible standard turret for all heavier tanks, but finally a choice was made for theAPX1, originally developed for the Char B1, costing ₣ 200,000 which brought the unit price to ₣ 610,000. The fifty vehicles were only delivered from May 1936.
Due to this delay a planned second order of a hundred, to bring total production to 150, to be made in 1935, was cancelled. It had been assumed that the lighter Char D2 could be quickly produced as an interim type, to speed the formation of the first Infantry armoured division of the Infantry.
Description
In essence the Char D2 is an improved Char D1. The different turret type used, increases its height somewhat to 266.6 centimetres; the hull is 175.5 centimetres high. The length of the hull, without tail, is 546 centimetres; its width is reduced to 222.3 centimetres through the use of a narrower track, 35 centimetres wide. The suspension is largely identical but the top rollers, to which a tension wheel is added, are placed somewhat higher to prevent track resonance, a persistent problem with the Char D1. The armour plate covering the three vertical coil springs consists of six instead of eight panels; mud-chutes are added below each top roller. There are three bogies per side, each with four road wheels, a coil spring and two shock absorbers. In front, and at the back below the sprocket, there is a tension wheel with its own damper; identical to the road wheels proper they bring the total number of such wheels to fourteen. Another change are the fenders with large stowage bins that give the false impression to be part of the main armour.
The production vehicles use far less welded sections than at first intended. To reduce the price, Renault has opted to implement a novel construction technique, using large flat screws, serving both as bolts and, applied heated, as rivets, attaching the main armour plates to each other by means of thin connecting steel strips. This way no internal girders, forming a real chassis, are needed. The armour plates are 40 mm thick.
Like with the Char D1 there is a crew of three, but the radio-telegraphy operator is sitting to the right of the driver instead of the commander, and the antenna, of the ER52 set, has been moved to a position next to him. To make room a hull machine-gun is absent. This new configuration had been demanded to create a roomier fighting compartment. Two command vehicles, series numbers 2016 and 2049, have a second antenna on the left to serve their ER51 long range set. The engine power has increased considerably to 150 hp by installing a Renault V-6 9.5 litres motor, but as the weight has increased to 19.75 (just below the twenty tonne limit) instead of the intended 15.5 metric tonnes, the gain in maximum speed is limited to 23 km/h. The gear box has four speeds. Four fuel tanks together holding 352 litres allow for a range of a hundred kilometres. The wading capacity is 120 centimetres, a trench of 210 centimetres can be crossed, an obstacle eighty centimetres high or a slope of 50% climbed. The hull has a fixed 7.5 mm machine-gun low in the glacis on the right side.
The commander is the sole occupant of the APX1 turret, acting also as gunner and loader for the 47 mm SA34 gun, which has a limited anti-tank capacity, and the optionally coaxial 7.5 mm Châtellerault machine-gun. The gun could fire two types of ammunition: a HE (High Explosive) called the Obus D with a shell weight of 1250 gramme and a muzzle velocity of 490 m/s; and an APHE (Armoured Piercing High Explosive), the Obus B Modèle 1932, with a shell weight of 1410 gramme, an explosive charge of 142 gramme and a muzzle velocity of 480 m/s. It rendered an armour penetration of just about 25 millimetres at a distance of a hundred metres, barely enough to be effective against light armoured vehicles.
| Specifications | |
|---|---|
| Weight | 19.75 metric tonnes |
| Length | 5.46 m |
| Width | 2.22 m |
| Height | 2.66 m |
| Crew | three |
| Armor | 40 mm |
Main
armament | 47mm SA34 Gun, later models 47mm SA35 Gun |
Secondary
armament | 2x 7.5 mm MG |
| Engine | Renault 6-cyl petrol 150 hp |
| Suspension | vertical springs |
Operational
range | 100 km |
| Speed | 23 km/h |
Source : Wikipedia
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