After World War 2 (1939-1945) proved the value of Self-Propelled Gun (SPG) systems and the efficient process of simply converting existing tracked chassis for the role, it fell to all nations in the post-war decades to keep pace and develop similar platforms going forward. For the rebuilding French Army, this led to the Nexter/GIAT Mk F3, a tracked vehicle mounting a 155mm main gun atop the chassis of the existing French Army AMX-13 Light Tank. Approximately 600 units were constructed to the Mk F3 standard and these emerged from the period spanning 1962 to 1997. The Mk F3 superseded the M41 "Gorilla" 155mm-armed platforms which were based on the World War 2-era M24 "Chaffee" Light Tank.
As was the case with other converted military armored vehicles, the Mk F3 retained much of the form and function of the original AMX-13 tank save for the obvious physical characteristic of lacking a turret. Instead, the 155mm howitzer was fitted over the hull roof, slightly offset to the right side of the vehicle. While eight crew were required for typical operation, at least two of these could ride on the vehicle itself - the rest brought up by a support vehicle also bring along the required 155mm projectiles. The track-and-wheel arrangement provided the necessary off-road travel capabilities when attempting to keep up with French Army mechanized divisions of the period and the hull was suspended by a torsion bar arrangement. Drive power was by way of a SOFAM 8Gxb 8-cylinder gasoline-fueled engine outputting at 250 horsepower providing the vehicle with a maximum road speed of 37 miles per hour and an operational range out to 190 miles. Armor protection was up to 20mm.
Because of its AMX-13 origins and only requiring seating for two, the Mk F3 could be kept a compact vehicle which aided in its transportation whether by aircraft or railcar. Dimensions included a running length of 20.4 feet with a width of 8.9 feet and a height of 6.9 feet. Its profile was low making it a harder target to identify on the battlefield at range. The vehicle was in the 20-ton range.
Design work on the Mk F3 began in 1952 and the system was in operational service for 1962. It became an efficient gun carrier for the French Army as it was a cost-effective solution and relatively easy to operate and maintain. The 155mm howitzer was a proven battlefield commodity and could fire it's HE (High-Explosive) payload out to target areas miles away. Detractors pointed out the system's lack of viable Nuclear, Biological, Chemical (NBC) protection for the crew which, during the Cold War, became a standard on most every vehicle fielded by every army of the world. The support crew was also exposed to all manner of battlefield dangers in combat zones as well as the elements for only two of the eight was officially protected under cover of armor.
Nevertheless, the Mk F3 became a popular product for the export market and the platform was taken on by the likes of Argentina, Chile, Cyprus, Ecuador, Morocco, Saudi Arabia, Peru, Venezuela, and Qatar. Aside from the French Army, the most prolific operator of the vehicle became Morocco with 100 units - the last of these delivered as recently as 1997. Extended production was primarily to fulfill foreign orders as the French Army had moved on to the modern GIAT GCT 155mm SPG vehicle from 1977 onwards. This SPG featured the more traditional approach of a turreted 155mm armament over a common tracked chassis.
In 2006, the Nexter brand label became GIAT Industries, lending its name to the Mk F3 product for a short period.