Manitowoc Published 10-09-2020, Control # 259-06 4-7
MLC80A-1/MLC90A-1/MLC100A-1/MLC100-1 SERVICE/MAINTENANCE MANUAL BOOM
PHYSICAL BOOM STOP
See Figure 4-5
Physical Boom Stop Angles
Physical boom stops (2) serve the following purposes:
• Assist in stopping the boom smoothly at any angle
above 59°
• Assist in preventing the boom rigging from pulling the
boom back when traveling or setting loads with the
boom at any angle above 59°
• Assist in moving the boom forward when lowering the
boom from any angle above 59°
• Provide a physical stop at 84°
Physical Boom Stop Operation
• When the boom is raised to 59°, the springs start to
compress (View A).
• As the boom is raised higher, spring compression
increases to exert greater force against the boom.
• If for any reason the boom is raised to 84°, the springs
fully compress to provide a physical stop (View B).
Physical Boom Stop Adjustment
The physical boom stops do not require adjustment.
LATTICE SECTION INSPECTION AND
LACING REPLACEMENT
Refer to Folio 1316 at the end of this section for lattice
section inspection and lacing replacement instructions.
WARNING
Collapsing Boom Hazard!
Physical boom stops must be installed for all crane
operations.
Physical boom stops do not automatically stop boom at
maximum operating angle.
Automatic boom stop must be installed and properly
adjusted.