h2g2 The Hitchhiker's Guide to the Galaxy: Earth Edition

WeE Brits only use two types of Mortar, the light Mortar (60mm)which is a platoon weapon and the 81mm which is a battalion weapon, both organic to the infantry battalion.

The mortar round is projected differently to an artillary round. The mortar round has a shotgun-like cartridge in the finned tailpiece. This is fired and the gases push the round out of the barrel. The 81mm Mortar has a fixed firing pin and the round is dropped onto it.

The gases escape from the tailpiece by a series of holes in the side. To increase the range, extra propellant is placed over these holes and ignites with the main cartridge. More propellant = more gases= higher pressure = more speed =longer range.

Modern medium (81mm)mortars are extremely accurate (within 5m of aiming point) once ranged. They have artillary type sighting equipment. Unfortunately, the high trajectory and relatively low speed of the round make it easy to spot using radar. Mortar tactics are usually set up, fire, move.

The light mortar is aimed by a white line along the barrel and the operator's experience. There is a small baseplate and no bipod. The barrel is supported by hand. The round is dropped in, the weapon 'pointed in the right direction', and a lanyard pulled which fires the round. Dispite the rather primitive arrangements, it is very effective.