Musée de l'Armée aux Invalides
Lat : 48.85820 / Long : 2.31390
General comments on this surviving gun :
Identical items in the same location :
Items covered by this file :
Historic context :
Although the idea is already in the air for some years, it is in December 1915 that the Colonel Estienne, already a pioneer of the military air force in France, writes a letter to the General Commander-in-Chief Joffre to explain the interests of 'terrestrial cruisers' in the current position war. The same month the Colonel Estienne met the engineer Brillié from the Schneider Company that was already highly interested by the US caterpillar trucks Holt used by the British Army as artillery tractors, and triggered so much enthusiasm that a design project was immediately launched.
An order of 400 tanks was passed in February 1916 to Schneider after some administrative slowing downs, for a planned delivery in November 1916, soon followed - with a total surprise for Estienne - by a second order by the Government of 400 tanks of a different design proposed by the competitor of Schneider, the Société des Forges et Aciéries de la Marine et d'Homécourt with its Saint Chamond works.
The first pieces of both tanks were delivered in September 1916 to the units in formation. The French tanks Schneider and Saint Chamond, named 'Chars' by the Colonel Estienne, were to have a disapponting first fire experience when used in Apriil 1917 on the lowlands at the east of the Chemin des Dames. The defects of the Schneider tank (catastrophic mechanical reliability, insufficient shielding, poor visibility, slowness, poor maneuverability on battlefields messy grounds, ...), similar to the ones of the even more cumbersome Saint Chamond tank only began to find a solution with the arrival of the Renault FT light tank.
For the main weapon of its tank built in the SOMUA works in Saint Ouen (Société d'Outillage Mécanique et d'Usinage d'Artillerie) that he had bought in 1914, Schneider chose its existing Mortier de 75 mm BS ('BS' = 'Blockhaus Schneider'). This small weapon was an evolution of the 75 T Schneider trench mortar that had been improvised in 1915 in order to participate in the building of a French trench artillery while using the immense stocks of defective 75mm fieldgun ammunitions. Compared to the trench mortar, the new weapon was keeping the same barrel (lightly elongated - 9.5 calibres vs 8.3) and a sliding block breech quasi-identical. But it was now equipped with a 2 cylinders recoil recuperation system and a spherical shield, and was placed on a pivot mount.
Integrated in the Schneider tank, the gun was placed in the front right section of the habitacle, pointing in an oblique direction vs the marching one. It was launching a 75mm fieldgun Mle 1897 high explosive shell, with a shortened cartridge providing it a slow initial speed of 200 m/s giving an efficient range of 600 m
Technical data :
- Complete description : 75 mm Schneider BS blockhaus mortar
- Design year : 1916
- Calibre : 75.00 mm
- Weight in firing position : 210 kg
- Weight for transportation : N/A
- Tube length in calibres : 10.50 (total length) - 9.5 calibres rifled part only
- Grooves : 24 to the right, constant 7 degrees angle
- Projectile weight : 5.3 kg (obus explosif normal)
- Initial speed : 200 m/s
- Fire rate : 4 rounds / min (recommended)
- Range : 2100 m (effective : 600 m)
- Elevation range : -20 to +20 degrees
- Direction range : 20 degrees total range (350 thousandths)