The GIAT GCT is the primary tracked, self-propelled gun platform of the modern French Army. The system is akin to the American M109 Paladin, the British AS-90 and the Russian 2S19 in both form and function, featuring a high-profile hull superstructure mounting a potent 155mm main gun and a tracked hull design. The configuration is proven and emerged from experiences of World War 2 armored warfare. The GCT has since been produced in the hundreds and forms the long arm of the Saudi Army while dozens of examples were shipped to Iraq prior to the 2003 coalition invasion. Modernization has kept this 1970s'era system viable on the modern battlefield for French forces.
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.
Power for the GCT was served through a Hispano-Suiza HS 110 12-cylinder, water-cooled, multi-fueled engine outputting at 720 horsepower and installed in the rear of the hull. This allowed for a maximum road speed of 60km across ideal surfaces and an operational range of 450km. The chassis was suspended atop a torsion bar suspension system which allowed for cross-country travel, allowing it to keep pace with the rest of the French mechanized formation.
The running gear includes five double-tired road wheels to a track side. The track links run about the wheels in the usual way, straddling either side of the armored hull. The drive sprocket is located at the rear of the arrangement with the track idler at the front. Five track return rollers are mounted along the upper portion of the track and are clearly visible as no side skirt armor is implemented into the design of the GCT.
The 155mm main gun was cleared to fire a variety of ordnance options including High-Explosive (HE). Additionally, the system could fire smoke, anti-tank mines and any rocket-assisted projectiles as needed. The howitzer nature of the weapon means that the 155mm system lobs its projectile in a trajectory against a given target area (as opposed to a direct fire field gun). The gun is mounted to the angled frontal panel of the turret which sports flat sides and rear, the rear section covering some of the engine deck. The recoil mechanism is clearly visibly at the base of the gun as it enters the turret. The barrel is capped by a double-baffled muzzle brake to help dispense with the inherently violent outgoing forces. The onboard ammunition supply totals 42 x 155mm projectiles.
Production of the GCT began in 1977 out of the GIAT Roanne facility and completed in 1995 to which 400 units were delivered. Initial versions were represented by the "AUF 1" designation and modernized versions later appeared as the "AUF 2". Beyond their operation by the French, the GCT (AUF 1 models) were sold to Saudi Arabia and Iraq. Saudi Arabia received 51 examples beginning in 1978 to Iraq's 85 which were delivered from 1983 to 1985.
The GCT retains an operational level status with modern French Army forces. Seventy units were modernized to the new AUF 2 standard (built upon the AMX-30B2 MBT chassis). The standard incorporated an new automatic loader with an increased rate-of-fire to 10 projectiles. Also, range of the main gun is slightly improved as is accuracy. The GCT turret is also more modular, able to be fitted across a wide range of existing MBT chassis.
The GCT has gone on to see some combat service in its long-running tenure. During the Iran-Iraq War of the 1980s, Iraqi Army GCTs were used to good effect against Iranian targets. French Army GCTs were then utilized in support of NATO forces during the Bosnia and Herzegovina campaigns.