Broderson IC-280-A, Accompaniment To The Installation, Operation And Maintenance Manual

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SHEAVE BLOCK AND DOWNHAUL WEIGHT
The capacity chart shows the approved hoist rope arrangements. The downhaul weight and
sheave blocks supplied by Broderson are specially designed to operate the Anti-Two-Block
system. Other blocks or downhauls may bypass this system and create a dangerous
condition. Notice the load limit for each hoist rope arrangement.
The keeper pins that pass through the sheave plates must be locked in place with cotters to
hold the line on the sheaves. The load line must pass through the center of the downhaul,
through the wedge socket, and the dead end clamped in the block, as shown in the figure
below.
When resting the downhaul or sheave block on the ground for changing it, use the following
procedure to prevent fouling the load line on the hoist. Raise the boom about 5 feet (1.5 m)
and lower the hoist until the hook nearly touches the ground. Then lay the hook on the
ground by lowering the boom, not the hoist.