Staff Writer (Updated: 7/13/2014):
In 1962, the French Army adopted the 155mm Mk F3 self-propelled gun to manage its long-range hitting power. The system underwent design as early as 1952 and entered production a decade later, realizing approximately 600 units before manufacture ceased in 1997. The 17-ton system fielded a 155mm main gun and was powered by a SOFAM 8Gxb 8-cylinder gasoline fueled engine while being crewed by four personnel (of which only two could actually be carried on the vehicle proper). Despite production ongoing into the 1980s, the French Army sought its replacement and looked to a fully-functional, enclosed track-and-wheel system mounting a 155mm main gun in a traversing turret. Development, therefore, began in 1969 on a such a system with GIAT (now Nexter) granted production of the new vehicle.
The new vehicle was adopted into French Army service as the "GCT" ("Grande Cadence de Tir"), built upon the existing chassis of the AMX-30 Main Battle Tank (MBT). An all-new boxy turret enclosure was developed housing the breech of the 155mm main gun which allowed for engagement at all angles. The weapon was given an automatic loader (though manual was still possible) which allowed for a rate-of-fire of eight rounds per minute with ranges out to 23,500 meters depending on projectile used (rocket-assist allowed for engagement ranges of up to 28,000 meters). Armor protection was 20mm at its thickest and defense was provided by 1 x 7.62mm or 12.7mm machine gun to counter light armored vehicles and low-lying threats. The vehicle was crewed by four personnel made up of the driver, commander, gunner and ammunition handler. Unlike the Mk F3 before it, the GCT now housed all of the vehicle crew in relative safety and, furthermore, the entire crew was protected from Nuclear, Biological and Chemical (NBC) threats. Four smoke grenade dischargers are fitted in pairs at the extreme lower corners of the turret front.