relatively new type of line used in steel band hoists. It is standard practice for overhead rigging lines and hardware to be rated with at least an 8-times safety factor to help ensure the protection of cast and crew. In other words, a line intended to support 100 pounds should have a safe working load of at least 800 pounds. Lift lines carry and transfer the loads of a fly system to the fly system infrastructure. The lift lines for manual rigging run from the batten up to loft blocks, across the stage to a head block, and down to the counterweight balancing the load of the line set. When running horizontally, between loft blocks and head block, lift lines typically follow a transverse path (from side to side) across the stage. Operating lines, also known as hand lines or purchase lines are what the crew uses to manipulate manual fly systems. Operating lines are connected to sandbags (in a hemp system) or the top and bottom of arbors (in a counterweight system). Operating lines are typically or in diameter. Lift and operating lines were commonly made of manila hemp. The rope was often referred to simply as manila. Use of manila had a number of issues. Splinters of fiber could get into hands and eyes. Humidity and temperature changes could significantly affect the length of the rope. Over time the rope slowly rots. Synthetic rope can reduce or eliminate these issues, while providing greater strength by volume. Some riggers have complained that rope burn is more likely with synthetics, and that wear and damage on a synthetic rope is harder to detect. The two most common brands of polyester rope in the theatre world are Stage-Set X (parallel-fiber core) and Multiline II (braided strand). Over time polyester rope became more popular than manila in hemp systems and for use as the operating lines in counterweight systems. The lift lines of a counterweight rigging systems are typically a specific type of steel wire rope known as galvanized aircraft cable (GAC). Oil-free diameter, 7 x 19 strand, GAC is the most common counterweight system lift line. It has a minimum cable breaking strength of approximately . Line control Load-bearing lines must be safely tied off, locked, terminated and/or connected to other rigging components to ensure line control and the safety of a fly system. Various methods are employed. Belaying pins are