What is the pulley assembly mounted at the top of the fly system through which the rigging lines pass?

• A. Loft block
• B. Purchase line
• C. Head block
• D. Main line

Answer: (C)

The topmost pulley assembly through which the rigging lines pass is the head block. In a fly system, lines enter the system at the ceiling/grid and are guided by this upper pulley block, making it the first and primary junction for the line travel toward the loft blocks and arbors. The loft block is a separate pulley mounted in the fly loft used for routing lines in more complex or extended runs, while the terms purchase line and main line refer to different parts of the operating lines, not the top-of-system pulley. So the name for that top-mounted pulley is head block.