The 2S12 “Sani” is a 120 mm heavy mortar system used by the Russian Army and other former Soviet states. First fielded in 1981, the 2S12 is a continued development on the towed mortars first used in World War II. 2S12 is in fact the designator for the combination of the 2B11 “Sani” heavy mortar with its transport vehicle 2F510, a GAZ-66-15 4×4 truck. The 2B11 weighs nearly 500 lb when fully assembled, and thus must be mounted to the 2×1 wheeled chassis 2L81 and towed to the emplacement site by the truck.
The GAZ-66 prime mover also transports the ammo load: 24 70-lb crates of 120mm HE mortar bombs, 2 bombs per crate, for a total of 48 available rounds. Once on site, it is unloaded from the transport chassis and manually emplaced by the crew of 5. It is the largest caliber indirect artillery employed at the battalion level.
There is also an improved model, the 2B11M, that can fire the laser-guided round “Gran” with a range of 7,500 m. 2S12A and 2S12B improved models are in service now.] 2S12A got a new “Ural” family transport vehicle with high power diesel engine and electric hoist for loading the mortar and a new base plate with a hinge that allows for pointing horizontally without turning the heavy support.