In
Stage Rigging mule blocks are a special designation for any
sheave which changes the direction of the cable which it is guiding. They can be found in two places in most
counterweight fly systems. The first set guides the cables from the
arbor to the
grid. The second guides them back down from the grid to the
batten.
Mule blocks are a major source of friction in the counterweight fly system. A mule block which is too tight creates excessive strain on the entire system and can lead to cable failure. Too loose and the cable can jump track bringing both the batten and the arbor to a sudden stop. Either can be very deadly on stage.
Part of the Stage Rigging Metanode