Manitowoc 777 Service And Maintenance Manual

Reference Only
HOISTS 777 SERVICE MANUAL
5-20 Published 10-01-2012, Control # 045-08
Measure the rope’s diameter across crowns of the strands so
the true diameter is measured as shown in Figure 5-14.
Wire rope shall be taken out of service when reduction
from nominal diameter is more then 5%.
Broken Wires
Thoroughly clean the wire rope so breaks can be seen.
Relax the rope, move it off pick-up points, and flex it as much
as possible. Use a sharp awl to pick and probe between
wires and strands, lifting any wire which appears loose or
moves excessively.
Wire rope shall be taken out of service when it has
following number of broken wires.
See Figure 5-15 for a description of lay length.
• Running Ropes (working lines) — six randomly
distributed broken wires in one lay length, or three
broken wires in one strand of one lay length.
• Rotation Resistant Rope — two randomly distributed
broken wires in six rope diameters or four randomly
distributed broken wires in thirty rope diameters.
• Standing Ropes (pendants) — more than two broken
wires in one lay length in sections beyond the end
attachment, or more than one broken wire at the end
attachment (Figure 5-16).
• Any Rope — one outer wire broken at the point of
contact with the core. The broken wire protrudes or
loops out of the rope structure.
NOTE: United States Steel states Replacement criteria for
galvanized strand boom suspension pendants are
25 percent of the outer wires fractured, or 10
percent of the total numbers, whichever comes
first.
Wear and Other Damage
See Figure 5-17 for examples of wire rope damage.
Wire rope shall be taken out of service if:
• Rope core protrudes from between outer strands.
• Severe corrosion – indicated by pitting – exists.
• Obvious damage exists from any heat source, to include
– but not limited to – welding, power line strike, or
lighting.
• Kinking, crushing, bird caging, or any other damage
resulting in distortion of wire rope structure exists.
FIGURE 5-14
WRONG
A925
RIGHT
FIGURE 5-15
A925
Lay Length is distance measured along
rope in which one strand makes one
complete revolution around core.
Core
One
Wire
One Strand
FIGURE 5-16
WARNING
Replace wire rope when more than one
broken wire appears at point marked by
arrow.
S140
Poured Zink Socket
S142
S141
S143
Hand Splice
Swaged Socket
Wedge Socket

Manitowoc 777 Specifications

General

Brand	Manitowoc
Model	777
Category	Construction Equipment
Language	English