Manitowoc Published 12-10-19, Control # 258-05 2-21
MLC90A-1/MLC100-1 OPERATOR MANUAL SAFETY INFORMATION
BOOM DISASSEMBLY SAFETY
NOTE The term “boom” used in the following instructions
applies to all lattice attachments (fixed jib, luffing
jib, mast, etc.).
Safe handling of lattice booms during disassembly is a
primary concern for preventing serious or fatal injuries. A
boom can collapse during disassembly if workers fail to
observe safe working practices.
Accidents during boom disassembly usually result from one
of three primary causes:
• Workers are not familiar with equipment or are not
properly trained.
• Disassembly area is not suitable.
• Safe procedures are overlooked because not enough
time is allocated for the task.
General
Safety decals (Figure 2-4) are placed near the connectors on
the boom sections as shown on the Boom Disassembly
Decal Drawing at the end of this section.
Workers involved with boom disassembly shall be trained
and experienced in the operation and disassembly of
construction cranes. Everyone shall read and understand
these instructions, the information in the Boom Assembly
Drawing, and the instructions in Section 4 before beginning
disassembly. Anyone who has a question should ask for an
explanation. One worker who does not fully understand
or fails to follow correct procedures can endanger other
workers.
Location
Select a suitable location for boom disassembly. It must be
firm, level, and free of obstructions. It should have enough
open space to accommodate the crane, the length of boom,
and – if required – movement of an assist crane or other
equipment. If possible, secure the area to keep unauthorized
personnel and vehicles away.
Pin Removal
When removing pins from boom sections, stand clear of pins
being removed. Even though the boom is resting on
blocking, individual pin connections may still be under load.
Pins can be ejected forcefully if the boom has any pressure
on it or if the boom is not supported properly.
Disassembly Precaution
Always block boom sections so they are securely supported
and cannot shift or move suddenly when pins are removed. If
there is any doubt about a boom disassembly procedure,
block tightly under boom sections before removing any
pin.
DANGER!
Collapsing Boom Hazard!
Prevent death or serious injury when disassembling boom
sections — read and adhere to the following instructions.
DANGER
Collapsing Boom Hazard!
Boom can collapse or jerk when pins are removed. To
avoid death or serious injury:
• Do not remove bottom connecting pins from any
boom section when boom is supported by pendants
as shown in Figure 2-3
, View A.
• Do not remove pendant connecting pins until
pendants are fully lowered onto boom sections as
shown in Figure 2-3
, View C.
• Do not remove bottom connecting pins from any
boom section when boom point is resting on ground
or blocking and boom rigging is slack as shown in
Figure 2-3
, View B.
• Never work or stand inside boom unless it is lowered
and securely blocked as shown in Figure 2-3
, View C.
• Do not stand or walk on top of the boom.
DANGER
Falling Boom Hazard!
Crane can tip or the boom can collapse if excess boom is
cantilevered. Never cantilever more boom than allowed in
rigging drawing or capacity chart.