have gloves, hardhats, safety glasses or goggles, and
safety shoes for all hands, sledge hammers, pliers,
crowbars, marlin spikes, extra cotter pins, and dunnage.
Always wear gloves when handling wire rope.
NOTE: When breaking down a lattice boom, take
the opportunity this provides to inspect items
thoroughly, such as the connecting pins, cotter keys,
and inside the connecting lugs for wear, rust, and
A common method used to break down a pin-
connected basic boom and add a section is as follows:
1. Set outriggers and swing the upper revolving
unit over the rear or side, depending on the make and
model of the crane.
2. Lower the hook block(s) to the ground and
provide slack in the hoist line(s). Next, lower the boom
and set the boom tip sheaves on a piece of dunnage.
3. Engage the boom hoist control lever to lower the
bridle assembly or boom mast to slacken the pendant lines.
4. To prevent the pendant lines from falling on the
ground, use tie wire or rope to secure the pendant lines
to the boom. Then remove the cotter pins and drive out
the main pins from the bridle assembly connections in
the pendant lines.
5. Position the bridle assembly on top of the boom
butt (fig. 12-26, view A). This is done by having the
operator engage the boom hoist control lever to tighten
the boom hoist lines until the bridle is positioned on top
of the boom butt. To align the pinholes, manually
position the bridle assembly using the crowbar. The
pins that are used for the pendant line connections are
Figure 12-26.-Boom hoist assembly connected to boom butt.