Primer (brass)
Adapter (steel)
Percussion fuse
Booster case, or Jacket, or Gaine. (cold drawn or pressed steel-machined)
Copper band or rotating band
Cartridge case (drawn brass)
GIRLS LOADING POINT-DETONATING FUSES FOR HIGH-EXPLOSIVE SHELL IN BODY-MACHINING DEPARTMENT OF A LOADING PLANT.
The explosion of an H. E. shell is really a series of explosions. The process of the burst is about as follows: The firing pin strikes the percussion primer, which explodes the detonator. The detonator is filled with some easily detonated substance, such as fulminate of mercury. The concussion of this explosion sets off the charge held within the long tube which extends down the middle of the shell and which is known as the booster. The booster charge is a substance easily exploded, such as tetryl or trinitroaniline (T. N. A.). The explosion of the booster jars off the main charge of the shell, T. N. T. or amatol. This system of detonator, booster, and main charge gives control of the explosives within the shell, safety in handling the shell, and complete explosion when the shell bursts. Without the action of the booster charge on the main charge of the shell, the latter would be only partially burned when the shell exploded, and part of the main charge would thus waste itself in the open air.