ISC Large Rigging Pulley, Yellow with Green Wheel

The ISC large rigging pulley is a block for redirecting a lowering line on removals and heavy pruning cuts, with yellow side plates and a green sheave that are easy to spot in the canopy. It hangs from a sling at the rigging point and lets the rope run with less friction and wear than a natural crotch.

Where a rigging pulley fits

On a removal, the rigging point carries the biggest loads in the whole system. Hanging a pulley from a sling there lets the lowering line run smoothly, reduces wear on the rope and the tree, and makes it easier for the ground crew to control the piece with a lowering device.

The bright yellow and green finish helps the climber and ground crew see the block at a glance. Compare other rigging blocks if you need a different rope size or rating.

Large rigging pulleys are usually paired with an eye-to-eye or ring sling sized for the stem at the rigging point. Keep the pulley high enough that the lowering line runs cleanly without rubbing on branches below it.

Rope sizing and inspection

Match the pulley to the rope diameter you rig with and to the rated strength of the sling and lowering device. Check the markings on the pulley for its working load and minimum breaking strength before use.

Inspect the side plates, axle, and sheave for cracks, grooves, and wobble, and make sure the sheave spins freely. Rig only within the rated strength of every component, inspect gear before each job, and make sure the crew is trained in rigging practice under ANSI Z133 and the manufacturer's instructions.