The Probert Encyclopaedia of Warfare

MORTAR

A mortar is a machine for projecting a bomb via a high trajectory at a remote target. Mortars are believed to have been first used at Naples in 1435, and the first was made in England in 1543. A modem mortar bomb is stabilized in flight by means of tail fins. The high trajectory results in a high angle of attack and makes mortars more suitable than artillery for use in built-up areas or mountains; mortars are not as accurate, however. Artillery also differs in firing a projectile through a rifled barrel, thus creating greater muzzle velocity.
Mortars began to be developed when the trench lines came into use in the Great War, so that missiles could be pitched into the enemy trenches. The German minenwerfer was an early and complex design, but the archetypal early mortar was the British Stokes Gun designed by Sir Wilfrid Stokes in 1915. This simple trench howitzer was a tube with a fixed firing pin at the bottom end, into which a bomb carrying a blank shotgun cartridge and some smokeless powder was dropped. The cartridge hit the pin, ignited the powder, and blew the bomb from the barrel.
Mortars are generally classified as light (with a calibre up to 60 mm, and a maximum range of 500 to 2000 meters); medium (with a calibre between 60 mm and 100 mm and a maximum range of 2000 to 6000 meters) and heavy (with a calibre in excess of 100 mm and a maximum range typically up to 9000 meters).
Research Mortar