Schneider CA1 - Description

Description

To the modern eye, the tank is hardly recognizable as such and appears as an armoured steel box resting on top of a caterpillar tractor. It has no turret, and its inconspicuous main armament is a fortification 75 mm Blockhaus Schneider, placed in a barbette in the right front corner of the tank. The right side had been chosen because the gunner had to stand to the left of the barrel to operate the gun. The cannon type was developed from a 75 mm trench mortar that had been adapted to fire from a fixed fortification position by adding a recoil compensator and a gun shield; in this configuration it weighed 210 kilogrammes. This short-barrelled cannon had a length of just 9.5 calibres. It fired the standard French HE 75 mm shell but with a reduced propelling charge, allowing for a muzzle velocity of only two hundred metres per second. This limited the maximum range to 2200 metres, the practical range was six hundred metres and the tank needed to close within two hundred metres of a point target to allow for some precision shooting. The ammunition stock is ninety vertically stowed rounds. Two 8 mm Hotchkiss Model 1914 machine guns, projecting from the flanks in large hemispherical ballmounts, and resting on pintles, complement the short 75mm gun. The right machine gun is, because of the room needed for the main gun, positioned more to the rear than the left one. To the right of the cannon there is a bin for twenty readily accessible 75 mm rounds. Three other bins are positioned respectively at the extreme right rear corner (fourteen rounds), to the left of the engine (thirty-two) and at the left rear corner (twenty-four). The latter is situated to the right of a bin, at the extreme left corner, for the stock of four thousand rounds of 8 mm ammunition.

Another unusual feature is the slanted overhang of the frontal part of the chassis which has the form of a pointed nose, ending in a high obliquely protruding steel spur. It had been designed for cutting through and crushing down German barbed wire, thus opening passages for following French infantry, originally seen as the primary function of the system. However this long overhang could cause the tank to ditch itself readily. The major dimensions of the tank are a length of 6.32 metres, a width of 2.05 metres and a height of 2.3 metres. The design is of the early so-called "box tank" type, in which the crew, propulsion system and all manner of equipment are not clearly separated. As a result there is no real fighting compartment. The room available to the crew is entered through a double door in the back of the tank and is extremely cramped. The crew consisted of a commanding officer who was also the driver; an NCO who was the gunner, two machine gunners, a loader who assisted both the cannon and the machine guns and a mechanic who doubled as a machine gun loader. Four of these six men had, at their assigned position, to crouch inside a 1.5 m (4 ft 11 in) high space between the roof and the tank's floor. They then had to stand within two narrow troughs, one, behind the driver's seat, used by the gunner and a second square one more to the back, between the suspension elements, used by the cannon loader and the two machine gunners. Most of the space however, had a height of just three feet between the roof and the covering of transmission and suspension: if the mechanic wanted to assist the right machine gun he had to lay on his belly to load it. All-around protection was provided by 11.4 mm steel plate, later improved by a spaced armour of 5.4/5.5 mm, raising the weight from 12.5 to 13.5 tonnes. The roof had 5.5 mm armour. The plates are partly riveted; the superstructure is largely bolted.

The 60 hp Schneider gasoline engine and its radiator are located in the front part of the tank, to the immediate left of the driver. The four cylinder, 135 x 170 9753 cc, engine is of a type specially constructed for the Schneider CA. It attains its maximum output of sixty horsepower at a thousand rpm. The three forward speeds plus one reverse gearbox, as well as the differentials, which can be engaged by brakes to steer the tank, are all located on the rear axle. They are linked to the engine in the front by a driveshaft. The tank's official top speed is only 8.1 km/h. Practical terrain speed was even lower at two to four km/h. At two kilometres per hour the vehicle can climb a slope of 55%. The capacity to overcome obstacles is further improved by two short climbing tails, fitted to the left and right of the lower hull rear. The lower profile of the tails is curved, allowing the vehicle to gradually raise itself above a trench floor, until its centre of gravity shifts over the edge causing its hull to suddenly tumble forward. The suspension consists of seven double road wheels attached to two bogies, the one in front carrying three, the other four. The rear bogie is sprung by two vertical coil springs, the front one larger than the rear one. The front bogies of the left and the right, each sprung by a vertical coil of narrow diameter, are connected to each other by means of a yoke-like transverse beam, itself attached to the hull bottom by two wide vertical coils springs, diminishing rolling and tilt when crossing rough terrain. Ground clearance is forty-one centimetres. There are five small return rollers. The six-spoked idler is attached to the front bogie and can thus move vertically to some degree. The sprocket, having twenty teeth, is however fixed in relation to the hull. It has a somewhat larger diameter than the idler, causing the upper track profile to slope slightly downwards to the front. The track consists of thirty-three flat links with a width of thirty-six centimetres.

As the traverse of the main gun was limited, it had first to be pointed in the general direction of the target by the driver-commander swivelling the entire vehicle. To facilitate this, a small rectangular frame is fitted on the right side of the nose of the tank. Looking through it, the driver had a sightline parallel to that of the cannon in a neutral position. In practice, the commander had a too limited view of his surroundings through the small hatches to his left, front and right and had to resort to lifting his head out of his rectangular top hatch to observe the enemy. Small rectangular hatches, fitted with a vision slit, are further present to the front of each machine-gun. The main ventilation is provided by a large skylight slit running along the midline of the hull. It is doubly roofed with the lower roof having a second slit in its top, while the higher roof has open lower sides, creating oblique oblong ventilation channels through which fresh air can be sucked in from the outside. The top roof is the highest element of the vehicle. With later production vehicles, polluted air is removed through a broad ventilation grid in the nose, having a recessed armour plate below it.

The vehicles were delivered by the factory painted in the standard grey colour used by the Artillery Arm and other branches of the army and that was often called "artillery grey". It was a rather light pearl grey shade. At first, by the Section Camouflage in the field a specially designed complex striped flame pattern was added consisting of narrow vertical red brown, dark green and yellow ochre patches, delineated in black. This was intended to break the contours of the vehicles. To some observers, it made them seem strikingly colourful. The original grey paint was perhaps only partly covered, including it in the ensemble; an alternative interpretation of the lightest patches seen in black-and-white photographies is that it represents a light green hue. Later, when the appliqué armour was added a much simpler scheme was used where the same hues were shown in large irregular area's, again demarcated in black.