Definition
A fan is any arrangement of tubes angled symmetrically either side of the vertical, so that the effects open in width rather than height. It comes in three forms: the fan cake whose tubes are glued in a Z, W or V pattern; the candle fan mounted on a board; and the angled mortar rack, where five to ten tubes of 50 to 100 mm draw a spray of comets or bombettes. The spread commonly ranges from 60 to 120 degrees. A fan gives width to a display fired from a narrow line, underlines the façade of a building or the surface of a lake, and forms the basis of wave sequences where fans fire from left to right.
In practice, for the display company
A fan widens the fallout zone: the outer tubes throw their effects sideways, and that must stay within the safety perimeter. PyroDesk records the spread angle of each piece or rack, and PyroSimulator draws the actual sheet of trajectories, so you can check the width of the display against the site plan and time the waves.