F. Flying & Rigging Systems
Head Block
head block, stage pulley, fly system head block
What is a Head Block?
A head block is a multi-sheave (multi-groove) pulley assembly mounted at the top of the fly tower above the stage. It redirects the lift lines from the horizontal (above the stage) to the vertical (down to the counterweight arbor or hoist). The head block is a critical load-bearing component of any flying system.
Key Specifications
| Parameter | Typical Range |
|---|---|
| Sheaves | 4 – 30+ grooves |
| Sheave Diameter | 300mm – 600mm |
| Load per Sheave | 200kg – 500kg |
| Material | Cast iron or machined steel |
| Bearings | Sealed ball bearings |