C.W.S.A. 3-Man Mortar Drill
#1- commands the piece and serves the muzzle [swabs, loads, and aims].
#2- serves the vent [brings ammunition and fuse, raises and lowers the tube, blocks vent with thumbstall, fires piece with linstock].
#3- serves the ammunition box and acts as safety [measures charge; hands charge, ball, patch and fuse to #2; keeps time].

“Prepare to Load”
A. #3 gives charge, patch and ball to #2, who caries them to #1.
B. #2 then elevates the tube to vertical and blocks the vent.
C. #1 loads powder, patch and ball.
D. #2 lowers the tube and unstops the vent.
E. #1 then aims the piece.

“Pick and Prime”
A. #3 gives the precut fuse to #2.
B. #2 pricks the vent, then places the fuse.

“Prepare to Fire”
A. #2 takes the linstock and lights the fuse, calling “fire in the hole!”
B. #1 places himself to best observe effect of fire.

[Note a safety barrier must be in place behind the vent.]

When the mortar fires, #3 starts the stopwatch to time for three minutes to elapse before starting the sequence again. During this time #2 elevates the muzzle and blocks the vent while #1 sponges the tube.

[Source: Brent Clancy, C.W.S.A. Inspector General, as related to Steve Short]