SmartROC T35/T40 21 Winch
137 No: 7026962571.1.7027002891 en-US
221–240 10 19 5 10
In wire ropes with several layers of strands, only the outer, visible layer is considered. In
wire ropes with steel cores, the core is regarded as an inner strand, and is not included. In
the event of a wire break, two ends can be visible.
21.7.2 Checking Wire Rope for Strand Breaks
If there are strand breaks, scrap the wire rope.
21.7.3 Checking Wire Rope for Surface Wear
Inner surface wear is caused by friction between the wires and the strands.
Outer surface wear is caused by friction between the cable drums (rolls) and the wire rope
under pressure (acceleration and braking). Outer surface wear is visible through the forma-
tion of reflected images on the outer wires.
Surface wear is increased through faulty or no lubrication, increasing the effect of dirt and
dust. Surface wear reduces static tensile strength through reduction in the wire ropes
metallic cross section and dynamic strength through surface wear nicks. If the wire ropes
diameter decreases more than 7% in relation to the nominal diameter of the wire rope, it
must be scrapped. It must be scrapped even if no wire breaks are detected.
21.7.4 Checking Wire Rope for Corrosion
Corrosion is especially problematic in marine environments and in areas where the air is
polluted by industrial emissions. Corrosion can reduce operational strength through rust
spots and static tensile strength through a reduction in the cross section of the wire rope.
Severe corrosion can reduce elasticity.
Outer corrosion can be easily detected through visual examination.
Inner corrosion is more difficult to detect. Inner corrosion is characterized on the following:
• Absence of gap between the strands in the outer layer of the wire rope, often with wire
breaks in the strands.
• The wire rope diameter varies.
The parts of the wire rope that are bent over discs usually have a decreased diameter. At
any sign of corrosion, an authorized person must check the wire rope. If inner corrosion is
detected, the wire rope must be scrapped.
21.7.5 Checking Wire Rope for Decreased Diameter
A decrease in the wire rope diameter can occur because of material fatigue. Material fa-
tigue can be caused by:
• Inner surface wear and surface wear nicks
• Inner surface wear through friction between the strands and wires in the wire rope
• Fatigue in the plastic core
• A break in the steel core
• A break in the inner layer in a multi-strand wire rope
If the diameter if the wire rope decreases more than 10% in relation to the nominal diame-
ter of the wire rope, it must be scrapped. It must be scrapped even if no breaks have been
detected.
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