OCIMF_Mooring_Equipment_Guidelines_(Second_Edition)

(Barry) #1
Splices in used ropes should be examined for signs of wear. Look for strands which have
slipped in the splice and tucks which have become undone, as these upset the load balance.
The transition between (he splice and the rest of [he rope should be examined for signs of
intemal abrasion which may concentrate at this point. In double braid rope splices. look for
any indications that (he splice is pulling apart.

Eyes
Abrasion and fusion at the ioside back of tne eye are common problems. Wear occurs at this
point as the rope angle is changed under load aroWld a bollard or hook. On eyes which are
protected by thimbles. one should examine the rope in the mouth of the thimble for abrasion.
If significant abrasion or fusion is found, [he eye should be respliced.

In double braid rope. one should examine the crotcb of Ihe eye for broken strands. Make
certain the splice is not pulling out. Tt may be possible 10 resplice small double braid rope.
Large used double braid rope is very difficult to respJice and the rope may have to be
replaced.

6.3.6 Standard Specijicalions


The available standards generally specify only the manner in which the rope is made, the manner in
which il is to be tested and its minimum new dry strength. There are significant differences in the
test methods and the specified minimum breaking strengths among the standards.


The most widely recognized rope standards are those published in Great Britain (British Standards).
the United States (U.S. Cordage Institute), and Japan (Japanese [ndustrial Standards). The U .S.
and Japanese standards are generally only applied in the countrie.s of publication.


Tables 6.5, 6.6 and 6.7 compare the minimum required breaking strengths specified by these standards
for eight-strand polyester, nylon and polypropylene ropes. Table 6.5 also lists the German D1N
Standard 83 331 which requires about 10010 higher strengths for polyester ropes.

As indicated in the footnotes of eacb. table, the strength vaJues are not directly comparable due to
differences in testing methods. This must be considered when comparing ropes produced to different
standards.

Synthetic rope manufaclUring is subject to continuous development and improvement. Some manu-
facturers are reluctant to produce higher strength ropes because they are more expensive: they find
it difficult to market strooger ropes al increased prices when (here are no standards which recognize
Ihe higher specification. Nevertheless, some companies do now produce and market ropes. especially
those made from polyester, that are significantly stronger than tbe 'standard' product. These ropes
should be considered for mooring applications since they will be lighter than a standard rope at
generally Ihe same cost and strength.
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