What is the movable carriage that holds counterweights and travels along the runway to raise or lower the batten?

• A. Main line
• B. Arbor
• C. Rope lock
• D. Turnbuckle

Answer: (B)

In a counterweight fly system, the movable carriage that carries the weights and travels along the runway to raise or lower the batten is called the arbor. The arbor sits on the track and holds a stack of counterweights that balance the load on the batten. When you pull the mainline rope, the arbor moves up or down along the runway, lifting or lowering the batten with the scenery or lighting attached. The counterweights make this movement smooth and controllable, so operators can raise or lower heavy loads with manageable effort.

The other terms are related but serve different roles: the main line is the rope you pull to move the arbor, the rope lock is a device that holds a rope at a set height, and a turnbuckle is used to adjust tension or alignment in the rigging.