normally the pins used to connect the bridle assembly to
the boom butt. If the crane is equipped with a boom
mast, the boom mast normally has a short set of pendants
that connect to the boom butt pinholes (fig. 12-26, view
B).
NOTE: Visually check the boom hoist drum to
ensure the boom hoist wire rope does not loosen and
cross wind on the hoist drum, resulting in crushing or
kinking the wire rope.
6. Tighten the boom hoist lines to support the
weight of the boom, but not so tight that the boom tip is
lifted off the dunnage.
7. Remove the cotter pins from the boom
connection pins and drive out the lower boom
connection pins.
8. After the lower pins are removed, engage the
boom hoist control lever and lower the bridle assembly
or mast, allowing the boom to separate at the bottom by
hinging on the top pins. hen lower the boom on a piece
of dunnage.
9. Remove the top connecting pins. Once
removed, engage the boom hoist enough to separate the
boom connections lugs.
When the boom breakdown is performed over the
rear of the crane, you separate the boom by (1) raising
the outriggers enough to move forward with the travel
unit and by (2) releasing the brakes on the hoist line(s)
to slacken the hoist wire rope, as the travel unit moves
forward to allow space to add a section(s).
When the boom breakdown is performed over the
side of the crane, you separate the boom by ( 1) releasing
the brakes on the hoist line(s) to slacken the hoist wire
rope and by (2) using a forklift to pick up the boom tip
carefully and maneuver it enough to provide adequate
space to insert a boom section(s).
A method for adding a boom section is as follows:
1. Have a forklift align the boom section with the
boom butt.
2. Reverse the crane until the boom butt top pin
connection lugs are connected with the top pin
connection lugs on the boom section.
The boom
breakdown performed over the side requires a forklift to
maneuver the boom section until the pins are aligned.
3. Once the top lugs are aligned, drive the boom
connection pins into the top lugs from the inside out and
insert the cotter pins.
4. Engage the boom hoist control lever to raise the
boom butt. This allows the top pins to perform as a
hinge that draws the bottom pin connection lugs
together.
5. Once the bottom lugs are aligned, drive the
boom connection pins into the bottom lugs from the
inside out and insert the cotter pins.
6. Raise the boom butt and boom section several
inches to clear the ground. Reverse the crane until the
top connection lugs of the boom section align with the
top connection lugs of the boom tip. Final alignment of
the lugs might require the use of a crowbar.
7. Once the lugs are aligned, drive the boom
connection pins into the top lugs and insert the cotter
pins.
8. Engage the boom hoist control lever to raise the
boom section and boom tip. This results with the top
pins performing as a hinge, drawing the bottom pin
connection lugs together.
9. Once the bottom lugs are aligned, drive the
boom connection pins into the bottom lugs from the
inside out and insert the cotter pins.
10. Reset the outriggers.
The procedures for connecting the bridle assembly
to the boom pendants are as follows:
1. Engage the boom hoist control lever to lower the
bridle assembly or boom mast to produce slack in the
boom hoist wire rope.
2. The next step is to connect the boom bridle
assembly to the boom section pendant lines. This is
done by disconnecting the bridle assembly from the
boom butt and manually maneuvering the bridle
assembly to connect with the boom pendants of the
boom section. To produce slack in the bridle assembly
may require manually feeding of the boom hoist wire
rope through the sheaves.
For cranes equipped with a boom mast, lower the
boom mast to connect the pendant lines.
3. When the pendants are connected to the bridle,
it is a good practice to insert the pins from the inside out.
This practice allows for a easier visual inspection of the
cotter pins inserted in the pendant line pins when the
boom is in the air.
4. The next step is to connect the boom section
pendants to the boom tip pendants. This usually requires
manual labor to align the boom section pendants to the
boom tip pendants. You may also have to engage the boom
12-14