St Chamond (tank)
From Wikipedia, the free encyclopedia
| St Chamond | |
|---|---|
 early model St Chamond |
|
| Place of origin |  France |
| Specifications | |
| Weight | 22 tonnes |
| Length | 8.7 m |
| Width | 2.7 m |
| Height | 2.4 m |
| Crew | 8 (commander-driver, gunner-loader, assistant gunner, mechanic, three machine gunners, reserve crewman) |
|
|
|
| Armor | 11–19 mm |
| Primary armament |
75mm gun |
| Secondary armament |
four 7.92mm Hotchkiss M1914 machine guns |
| Engine | 4-cylinder Panhard-Levassor (petrol) 90 hp (70 kW) |
| Power/weight | 4 hp/tonne |
| Suspension | coil spring |
| Speed | 12 km/h |
The St Chamond was the second French heavy tank of the First World War. Overall an inadequate design born of commercial rivalry, the war ended before it was replaced by British heavy tanks.
Contents |
[edit] Development
Originally the tank produced by Saint Chamond was meant to be identical to the Schneider CA. Early 1916, the proposed definitive prototype of this latter tank was prepared in an army workshop. Private Pierre Lescure designed the fighting compartment. Lieutenant Fouché lengthened the suspension to improve trenchcrossing abilities. In this form the prototype of the Schneider was called the Tracteur A - not for security reasons, but because nobody knew exactly how to call such vehicles; the word char was not yet applied to tanks. However Eugène Brillié, the chief designer working for the Schneider Company, rejected this prototype. He had invented a tail giving a shorter chassis providing the same trench crossing abilities for a lesser weight.
While Brillié began to design a second prototype (based on his earlier work on the Schneider CA-1), Schneider's main competitor, the arms manufacturer "Forges et Acieries de la Marine et Homecourt à Saint Chamond", was given a second order for 400 tanks. First they intended to build the same tank as Schneider. However Brillié refused to share his patented invention for free and Saint Chamond refused to pay. So the latter company, not even having been given the blueprints of the new Schneider prototype, had to base its design on the original Tracteur A. Because of this the designs of the two companies began to diverge already, as the Tracteur A was longer.
One of Saint Chamond's technical directors was colonel Émile Rimailho, an artillery officer who had become disgruntled over the meagre benefits he had received for helping design the famous Mle 1897 75mm field gun as well as the Mle 1904 155mm howitzer. After Emile Rimailho had joined the firm at Saint Chamond he designed a 75mm field gun somewhat similar to the Mle 1897 75mm gun he had co-designed with Ste Claire Deville. It was the Saint Chamond L12 Canon à Tir Rapide ('Rapid Fire Cannon'), on which he received a percentage for every gun being sold. This was too good an opportunity to let pass and Rimailho induced the Ministry of War to change the specification of their order so that the new St Chamond tank would be able to mount his gun, even though the army had never asked for such a capacity. To achieve this, a longer hull than on the Schneider tank was needed. The first prototype, now quite distinct from the Schneider, was ready in September 1916. Later, during 1917, the standard Mle 1897 75mm field gun eventually replaced the Rimailho designed gun.
When Colonel Jean-Baptiste Eugène Estienne, who had taken the initiative to create the French tank arm, learned of the order for 400 tanks more, he was at first very gratified. When it later became clear however they would be of a different tank type, he was shocked and wrote: "I am painfully surprised that an order has been launched of this importance without asking the opinion of the only officer who, at the time, had undertaken a profound study of the technical and military aspects involved and who had brought the supreme commander to the decision to take this path [towards a tank arm]"[1]
[edit] Description
As a result of Rimailho's manipulations, the new tank had become a rather cumbersome vehicle. It had no turret, but a large overhanging front compartment housing the long 75 mm gun, protruding from the nose. Within the forward fighting compartment was the driver, who was also the vehicle commander, on the left. On the right a machine gunner operated the front machine gun. This gunner was also responsible for traversing the main gun and the breech operation of the same which he could only do by getting out of his seat and using his left hand. A loader (referred to in some sources as the gunner) adjusted the gun elevation, observing the target through a large hatch in the front of the tank, which left him vulnerable and many were killed by enemy fire. A second fighting compartment at the back held one machine gunner next to the secondary driver position, from where the tank could be driven backwards by the mechanic in an emergency. Between these two compartments was the 90 HP engine over the tracks, partly protruding through the roof. Narrow passageways either side of the engine connected the compartments, each also containing a machine gun position.
Despite weighing 23 tons, the tank could manage a top speed of 12 km/h. This speed was seldom achieved in the field as the long nose was prone to dig into the ground. The relatively high speed was made possible by a petro-electric transmission. This also gave the tank simple controls, allowing for perfect gradual steering. However it tended to overheat, and breakdowns were very common.
Due to the short tracks and large body, the vehicle had much trouble crossing obstacles. This led to such negative reactions by the first crews to be trained that special mention was made of it to the General Headquarters: Nobody wants to serve on the Saint-Chamond. Second Lieutenant de Gouyon, head driving instruction at Marly, has publicly declared that it has become impossible for him to continue to direct this unit and, as he is a Member of Parliament, he will cause the Chairman of Parliament to put it on the agenda[2].
[edit] Variant
Originally the crew of eight was protected by 11 mm of steel armour. The addition of an extra layer of spaced 8.5 mm armour on the front and the sides improved protection. The roof was also redesigned with a slope so that satchel charges and grenades would slide off. The original observation cylinders on the top were therefore done away with, but were later replaced in the field with some low look-out turrets.
The very first St Chamonds were modified as recovery vehicles able to tow the lighter Schneider tanks. The first action as a fighting tank was 5th May 1917, mostly getting stuck in various trenches. Twelve units in total were formed with the St Chamond: Artillerie Spéciale No's 31-42.
Production petered out in March 1918, when at least 377 had been manufactured. Surprisingly, in action towards the end of the war the tank was more useful, as in a more mobile situation it was quite effective at destroying German gun emplacements (Nahkampfbatterien).
After the 165th vehicle the common, and cheaper, Model 1897 field gun was used instead of Rimailho's (profitable) L12 gun. About the same time a wider track was introduced. This version was later sometimes called the Modèle 17; this identifier was not in use at the time itself though.
After the war 54 were rebuilt as munition carriers; the remainder scrapped. There are unsubstantiated stories about Poland using the tank against the Red Army in 1920. If true these specimens were in all probability not from the Soviet Army - the latter never had been supplied with them and the French Expedition Forces to Russia were only equipped with FT-17's. Possibly they were bought from French scrap dealers.
One vehicle can be viewed, alongside other examples of the French tanks of WWI, in the Musée des Blindés at Saumur. It had survived, together with a Schneider tank of the same vintage, at the Aberdeen Proving Grounds Ordnance Museum in Maryland, USA, and was later donated to the French government by the Americans.
[edit] See also
Chars-francais.net (French)
[edit] References
- ^ Mathieu Detchessahar and Yannick Lemarchand, "Des Hommes et des Projects dans l'Urgence — La naissance du char d’assaut français, Annales des Mines p 47; quoting Lettre d’Estienne à Joffre, 1er novembre 1916. SHAT, 16 N 2121: « Je suis péniblement surpris qu’on ait lancé une commande de cette importance sans prendre l’avis du seul officier qui, à l’époque, se soit livré à une étude approfondie de la question technique et militaire, et qui ait décidé le général en chef à marcherdans cette voie »
- ^ Mathieu Detchessahar and Yannick Lemarchand, "Des Hommes et des Projects dans l'Urgence — La naissance du char d’assaut français, Annales des Mines p 47; quoting Note résumant la question du matériel d’artillerie d’assaut, G.Q.G., 28 novembre 1916. SHAT, 16 N 2121
|
||||||||||||||
