The Brandt Mle CM60A1, also known as the Brandt HB 60LP, MCB-60 HB, or simply as the Brandt 60mm LP Gun-Mortar, is a 60 mm (2.36 in.) gun-mortar. Unlike conventional infantry mortars, it was not designed to be mounted on a bipod and a baseplate, but rather in the turrets of armoured fighting vehicles. The CM60A1 could be fired at a very low angle of elevation, giving it a dual purpose as direct fire artillery. Its hydraulic recoil mechanism reduces peak loads, allowing it to be mounted in very light armoured cars, such as the Panhard AML-60, or wheeled armoured personnel carriers, like the Panhard M3.
Development history
The Brandt Mle CM60A1 was developed as a result of French counter-insurgency experiences during the Algerian War. France had initially favoured the deployment of swift, lightly armoured cars against the Algerian National Liberation Front (FLN), including the M8 Greyhound and Panhard EBR. However, these vehicles had been designed for conventional combat on European battlefields and proved poorly suited to Algerian conditions; their heavy anti-tank armament also risked collateral damage and was of limited usefulness in fighting off guerrilla raids. The French Army wanted a much lighter, more efficient vehicle that was easier to maintain and initially adopted the Daimler Ferret for this purpose. Nevertheless, Ferrets could only be armed with a single general-purpose machine gun, and were regarded as inadequate for offensive purposes. A number of French defence contractors took up the challenge of creating yet another new vehicle of similar dimensions to the Ferret but carrying a mortar, which was regarded as more effective than a large gun system at breaking up ambushes and suppressing dispersed FLN positions. The result, the Panhard AML-60, entered service in 1961. AML-60s were fitted with an HE-60-7 turret developed by the Compagnie Normande de Mécanique de Précision (CNMP), which mated the CM60A1 mortar to twin co-axial machine guns or a single co-axial 20 mm autocannon. This turret could store about 43 mortar projectiles. The CM60A1 was unique in that it was the first turret-mounted, breech-loading, dual-purpose mortar to be mass-produced. Its turret mount gave it continuous traverse and, unlike muzzle-loading infantry mortars, it could engage targets of opportunity at close range that could not otherwise be suppressed with indirect fire.
The CM60A1 had a hydraulic recoil system and could be loaded with standard mortar ammunition for indirect fire support, as well as specialized direct fire ammunition. It could still be muzzle loaded from outside the vehicle, but was unique in its opening breech locked by a falling block much like direct fire artillery. The firing pin was automatically withdrawn when the breech was unlocked, reducing the likelihood of misfires. Different variants of the CM60A1 were produced with electrical or mechanical firing mechanisms. A hydraulic buffer provided a recoil of 135 mm.
Ranging was visual and conducted through the turret sights. Due to the lack of a modern fire control system in the HE-60-7 turrets, range to target had to be estimated by the vehicle crew. This required a series of precise but time-consuming calculations to be made by the crew commander for ascertaining firing angles.
Brandt's Mle CM60A1 design proved to be an immediate export success, as South Africa placed an order for 350 AML-60s in 1961, over half of which were to be assembled locally with French technical assistance. A South African military delegation visited France between November 22 and 28 that year to discuss the manufacture of the HE-60-7 turrets and armament under licence. By 1965, South Africa had purchased 450 CM60A1s for the future production of its modified Eland-60 armoured cars, along with a licence for both the mortar and its associated ammunition, which was granted by the French government's Direction technique des armements terrestres (DTAT). CM60A1s manufactured in South Africa under licence were designated K1. The South African Army also referred to this weapon as the M2 (not to be confused with the US M2 mortar).
Throughout the 1960s, CM60A1s were exported with the AML-60 to Algeria, Burundi, Cambodia, Côte d'Ivoire, Iraq, Ireland, Morocco, Nigeria, Portugal, Rwanda, Saudi Arabia, Senegal, and Spain. Some governments favoured the purchase of the lightly armed AML-60 model as opposed to the heavier AML-90 due to its comparatively attractive cost.