Definition
A rack is the wooden or aluminium frame that holds a group of mortars together, in a fixed orientation and apart from each other. A standard rack takes 5 to 25 mortars of one calibre, in a row or fanned, upright or angled by means of wedges or adjustable legs; “angle racks” let each tube be set separately. The rack turns a long, uncertain loading process into a transportable module ready to be wedged and wired on the firing site; it is also what stops a mortar from tipping over if a shell bursts on the ground. Large-calibre racks, from 150 mm up, are often individual and ballasted. Every rack carries a number that appears on the firing plan and on the site plan.
In practice, for the display company
The rack is the unit of loading and wiring: the show is prepared rack by rack, each tube carrying its label and cue number. PyroDesk manages racks as the desktop application did, with their list of tubes, calibres and angles, prints the rack sheet for rigging and passes it to the subcontractor portal without showing prices.