Wahlberg 241, User Manual

Page: 27 / 40

241.805.012 27 Date: 2017-10-24
Wire discard criteria
When the wire rope is exposed the following guidelines can be used to control whether
the wire must be discarded. The following serves as guidelines and if any of the discard
criteria are reached, the winch must immediately be taken out of service, and the
wire replaced, before using the winch again.
The wire rope should be discarded when:
− When the overall diameter of the rope is reduced by 8 %, or the outer wires
have lost its diameter by 33 % through wear. This reduction in diameter of the
rope is measured on a portion of the rope which has been subjected to abrasion
and stresses with respect to the portion of the rope which is subjected to
stresses but not abrasion e.g. portions near drum or anchorage.
− When there is evidence of considerable plastic wear or surface embrittlement.
−
When the diameter of the rope has suddenly reduced or the lay length has
suddenly increased or decreased.
− When there is evidence of severe corrosion like chain pitting.
− When there is any evidence of internal corrosion in the rope. This can be
recognized by slackness of outer wires due to the internal wires corroding
away.
− When the rope has been subjected to mechanical damage, crushing, kink,
bends, bird cage, etc.
− When the core of the rope has collapsed.
−
When the rope has been subjected to a high temperature or heat due to fire.
− When the rope has been subjected to severe shock load or over load due to an
accident with the winch.
Figure 2: When using a calliper to measure wire rope diameter,
measure from crown to crown, not from valley to valley.