Counterweight

In a typical counterweight fly system, an arbor (carriage) is employed to balance the weight of the batten and attached loads to be flown above the stage. The arbor, which carries a variable number of metal counterweights, moves up and down vertical tracks alongside an offstage wall. In some lower-capacity fly systems, cable guide wires are used instead of tracks to guide the arbors and limit their horizontal play during vertical travel (movement).

The counterweight operator should give warnings to people on stage by shouting "Heads on stage" and "Chins on stage" loudly when flying the CW bar in and out.