In Libya, the Italian military forces were organized under the Comando Superiore Forze Armate Africa Settentrionale (A.S).
The main combat version, the L.6/40 soon proved to be of little value against the British armor then in use in North Africa and was obviously ripe for the usual limited traverse anti-tank gun treatment. It was not long in coming when Fiat-SPA and Ansaldo combined to use the chassis for the basis of a tank destroyer.
Initially, the Semovente da 75/18 was internally identical to the M13/40, the major difference being the 75 mm Ansaldo L/18 field gun fixed in the superstructure, and the obvious upper hull changes. By 1942, Italy was producing armored vehicles that were better suited for desert conditions than their previous models
The Semovente da 149/40 was a completely unprotected weapon as the long gun barrel was placed on an open mounting carried on the turretless tank chassis. The gun crew stood in the open to serve the gun that had is trunnions mounted right to the rear to absorb some of the recoil forces produced on firing.