Mortar[]
From PyroGuide[]
Mortars
Fibreglass mortarsA mortar is necessary tool used to fire shells up into the air. It is essentially a large tube that is sealed at the bottom, and is open at the top. It is used in association with cylindrical or spherical shells. The shell is launched by placing a lifting charge underneath, in the bottom of the mortar tube. Typically mortars come in a range from 1" to 24", 2" and 3" mortars being very common among enthusiasts.
Mortars have two parts: a tube--composed of HDPE or thick cardboard piping--other plastics and metal should never be used due to the fact that if a shell ever exploded in the tube, the results would be devestatingly similar to those produced by a fragmentation grenade--and a base, which can be composed of just about anything.
When setting up mortars for a display they should be located and angled so that the aerial shells are carried away from the viewing area to the fallout area. Where the display site is fully surrounded by the viewing area, the mortars should be located and slightly angled to compensate for wind and the configuration of the display site.
The person operating the mortars should ensure that loaded mortars have protection from rain, burning debris, and flash over etc. The provisioning of a witness device on each individual mortar, such as aluminium foil or plastic wrap, will also provide a witness for the operator after the display to see whether theaerial shell has functioned so appropriate procedures can be undertaken.
Immediately before an aerial shell is loaded into a mortar, the mortar must be examined to confirm that no water, foreign bodies or debris have entered during the set-up operations. The shell assembly must be loaded into the mortar so that the lifting charge is beneath the shell.
While being lowered into the mortar, the aerial shell must be held by its fuse or by lowering cord (where provided), so that the shell comes gently to rest at the bottom of the mortar, resting on its lifting charge. Once the shell is loaded into the mortar, no person must pass any part of his or her body directly over the