were pressing throughout the winter, though various trials were made. In March 1917, the demand of army headquarters was increased, being based on the requirements for an offensive on a loo-km. front. This entailed the production of 3,000 light, 400 medium (improved Schneiders) and 150 heavy tanks. In May an order was given for i ,000 Renault machines in addition to 150 which had been ordered in March as "command" tanks. Discussion as to design, armament and manufacturing facilities and trials continued during the summer of 1917. In Oct. it was settled that in addition to the 1,150 already on order, 2,380 more should be made, or 3,250 in all, the work being dis- tributed between four French factories, the whole to be delivered by the end of July 1918. Of the total, 1,000 machines were expected to be ready by March 31 1918, for the contemplated offensive in the spring, and 1,000 were to be manufactured in the United States, of standard American parts and equipped with Liberty engines. The decision to devote so much money as this entailed and so much of the manufacturing power of the nation at a moment when the demands for munitions of war of other kinds was at its height illustrates the importance now attached to the new arm. The British success at Cambrai seems to have had considerable effect in influencing those who were still sceptical of the value of the tank and of the wisdom of relying on it for future operations. In Jan. 1918 a supplementary order was placed for 470 machines, the final total figure fixed for' pro- duction in France being 4,000, divided into 1,000 armed with machine-guns, 1,830 with the 37-mm. gun, 200 signal tanks, and 970 for a reserve armed with the 75-mm. gun.
The Renault tank differed greatly from the Schneider and St. Chamond machines. Not only was it considerably smaller, but the tracks were outside the body and not underneath it and extended to a considerable distance in front. Its total length, without the mov- able tail, was 4-100 metres; its breadth 1-740 metres, and its height 2-140 metres. The body was supported on hollow longitudinal girders by a hinge arrangement at the rear end and suspended on powerful springs in front so that the front of the frame and body were capable of relative movement. Each girder was carried by springs on four bogies supported by wheels running on the tracks. The idle track pulley in front was of larger diameter than the driving-sprocket at the rear and this and the projection of the tracks gave the machine a greater grip in climbing over obstacles. The upper portion of the track ran in spring guide rollers which were arranged to regulate the track tension automatically. The interior of the tank consisted of a driver's compartment in front and the engine- room behind. The crew comprised two, one officer or N.C.O., who was also the gunner, and one man who was the driver. The driver was seated ; and also seated, or standing, behind him was the gunner, with his head and shoulders in the turret. The latter revolved on ball-bearings which allowed of all-around fire, and was furnished with a lock and a door at its back. The whole of the machinery, engine, radiator, clutch, transmission gear and petrol tank were in the engine-room, separated by a steel bulk-head pierced by openings closed at will from the driver s compartment. Power was given by a four-cylinder Renault engine of 35 H.P., with the usual transmission. Steering and control could be done by one man. Protection consisted of hardened steel plate 16 mm. thick for the vertical portions (proof against the armour-piercing bullet) and 8 mm. for other parts. The armament was either a 37-mm. Puteaux semi-automatic gun, or a Hotchkiss machine-gun; and 240 rounds including 40 rounds of case shot, or i ,820 rounds of S.A.A. were carried. Fully loaded the female weighed under 6i tons and the male just over 6J tons. There were four speeds ahead and astern giving to the tank a maximum speed on the flat of 7-78 kilometres. It could climb slopes up to 45 and span openings up to 1-80 metres in width, in which it was assisted by the movable tail. This was the machine upon which the French relied for the operations of 1918. The question of the provision of Renault wireless signal tanks was taken up in May 1917, and a machine capable of sending and receiving wireless messages was constructed.
In the autumn and winter of 1917 the reorganization and training of the ArtUlerie d'Assaut continued with a view to its expansion. In addition to the medium tanks still being delivered, it was expected, by March 31 1918, to receive 800 of the Renault tanks then due. The establishment of the ArtUlerie d'Assaut was tentatively fixed as follows: four groupements (16 groupes) of Schneider tanks, with four repair sections; four groupements (12 groupes) of St. Chamond tanks, with four repair sections; 36 companies of Renault tanks; one groupe depot for Renault tanks; one salvage groupe; three park sections. The number of Renault companies was fixed at 30 before the end of the year.
The organization of the Renault tanks, which were regarded as an infantry arm, was to be by sections, companies, battalions and later by regiments and brigades. A company comprised three sections of five tanks each and an echelon de combat of 10 tanks (of which one was a wireless signal tank), 1 or 25 machines in all. A battalion contained three companies of 75 tanks. Changes were made in the administration, and Marly-le-Roi was given up as a training centre, two army group-training centres being established at Mailly-Poivres and Martigny, the training facili- j ties and auxiliary services generally were increased and elab- orated, and the relation of the ArtUlerie d'Assaut to the Ministry , of War was defined and simplified. All these preparations were carried out with a view to the cooperation of the tanks in the ' French offensive in the spring.
When the German advance on March 21 1918 wrested the initiative from the Allies, amongst other results it upset all the plans carefully worked out for the French tanks. Instead of taking part in mass in a great offensive, as intended, whatever tank units existed had now hurriedly to be collected and thrown into the defence. The factor ruling the speed of the creation of the service had all along been the rate at which the materiel was delivered. This, for various reasons, was always much behind the scheduled time arranged. On March 21 the medium tanks in a serviceable state fit for immediate use amounted in number to 245 Schneider and 222 St. Chamond, or 467 machines of an obsolescent type, and of the new Renault tank i machine ready for action, with the army. (By the beginning of April over 400 had been turned out by the factories. But these were made up of training machines without armament or armour, pattern ma- chines, machines issued to the American army for training, and those under test.) Moreover the approach of the Germans necessitated the hurried evacuation of the tank centre and main park at Champlieu. And so, not only was the new arm, still in its early infancy, forced to face an entirely fresh situation with improvised measures, but part of its organization was sud- denly torn up almost before it had taken root. Great efforts were made both to assist in coping with the immediately urgent necessity of checking the enemy's advance and to prepare for subsequent action. Champlieu was reoccupied in the beginning of April, when the progress of the Germans to the north was checked; but a central reserve park farther from the front, near Fontainebleau, and three others were established.
Operations during April and till the end of May were confined to the medium tanks, which alone were available and mobilized. Four groupements of Schneider machines were allotted to the' III. and I. Armies, joined later by three of St. Chamond machines. All the actions now undertaken were, as was the case with the British tanks, of the nature of minor counter-attacks, and not such as the tanks were best suited for. They took place, on April 5, at Grivesnes; on April 7 at Senecat; and on April 8 at Cantigny, the last being in cooperation with the American troops. The most successful was the last, in which the action of tanks had been legislated for. The artillery bombardment was short and portions of ground were left unshelled to allow of the passage of the tanks. Though not actually fighting, the tanks were at this period continually being moved about in readiness, and to save wear and tear the system was adopted of transporting them by road on special " tugs " drawn by caterpillar tractors.
On May 31 the Renault machines received their baptism of fire on the E. of the Forest of Retz. Three battalions of these machines now ready were allotted to the VT. Army, and were brought up by train, on lorries and on tugs. Six sections had to be flung into the fight. Without previous reconnaissance or any liaison with the already exhausted Colonial infantry, who had never seen a tank, they had practically to make a cavalry charge in broad daylight, without a smoke-screen, across a mile
1 Owing to delays in manufacture and difficulty in technical training the first wireless signal tanks did not take the field until July 1918, when after some practice they were found of great value. As has been stated British tanks were fitted with equipment and trained operators ready for the field in July 1916.
