Batignolles-Chatillon 25t a prototype that almost revived the concept of modern medium tank
In the beginning of the fifties, development of the very effective HEAT ammunition which basically negated the (homogeneous steel) armor of existing heavy tanks, for the moment revived the idea of medium tanks. Batignolles-Châtillon, renowned manufacturer of railway cars and locomotives, started the development of a new medium tank that eventually evolved into an “as light as possible” main battle tank concept. Batignolles-Châtillon's Char 25t had a very flat hull, with 80 mm of highly sloped front armor, hydraulic suspension with six wheels and a oscillating tower.
Oscillating Turret
The oscillating turret design, lacking a conventional gun-mantlet, is in two separate parts, with an upper and lower part connected by two hinge bolts or pivots, the gun being fixed within the upper section. The horizontal movement of the gun (traversing) is conventional, but the vertical movement (elevation) is achieved through the pivoting of the entire upper section with respect to the lower section. This method of elevation has two main advantages. Firstly, it allows for a smaller turret volume, as no internal space is needed for the vertical movement of the gun breech. Secondly, it allows the use of a relatively simple auto-loader fed by multi-round magazines,
Batignolles-Châtillon 25t close up of the oscillating turret
achieving a very high rate of fire as the gun's position was fixed with respect to the auto-loader located in the back of the upper turret in a protruding bustle. The oscillating turret was a very fashionable concept in the fifties, and also applied in some American projects, such as the T57 and T58. Only the French, however, produced operational systems.
Armament And Other Design Features
Main armament consisted of a powerful 90 mm gun, with initial muzzle velocity of 930 m/s. As a secondary armament, the Char 25t had a single 7,5 mm machine gun. With very compact dimensions of only 5.67m in length, 3.16m in width, and 2.37m in height, mass of the vehicle stayed below 25 tones. With such a low weight, the Char 25t could achieve a very high top speed of 65 km/h. The crew consisted of four; a commander and gunner placed in the turret, while the driver and radio operator were placed in the hull.
Batignolles-Châtillon 25t at depot in Saumur tank museum (France) awaiting restoration
Fate
Batignolles-Châtillon Char 25t lost the competition for the next French main battle tank in favor of the AMX 30, mainly because of an unreliable and maintenance intensive hydraulic suspension, as well as fading interest in the oscillating turret concept. It was relatively tall (compared to its size) and it was very difficult to make gas tight. In the era of cold war with a high risk of nuclear and chemical warfare, this was considered a major flaw. However, some of the technology was used in later vehicles.
Two prototypes were built.
In the beginning of the fifties, development of the very effective HEAT ammunition which basically negated the (homogeneous steel) armor of existing heavy tanks, for the moment revived the idea of medium tanks. Batignolles-Châtillon, renowned manufacturer of railway cars and locomotives, started the development of a new medium tank that eventually evolved into an “as light as possible” main battle tank concept. Batignolles-Châtillon's Char 25t had a very flat hull, with 80 mm of highly sloped front armor, hydraulic suspension with six wheels and a oscillating tower.