GUIDELINES
FOR
MARINE
LIFTING
&
LOWERING
OPERATIONS
0027/ND Rev 11
Page 34 of 84
7.8.7
Bending at the butt and tuck location of a grommet shall be avoided (unless specified by the supplier,
see 7.8.6) and the butt and tuck locations shall be clearly marked on the grommet.
7.9
WEAR AND APPLICATION FACTOR
w
7.9.1
The wear and application factor,
w
, for steel wire slings and grommets with a material factor in
accordance with section 7.9.4 and inspection requirements in accordance with Section 15.2 shall be
taken as 1.0.
7.9.2
For frequently used slings without thorough inspection before each lift, a minimum wear and
application factor
w
of 1.10 is normally required.
7.9.3
For fibre slings with a protective jacket, the wear and application factor,
w
, can be taken as 1.0, unless
the jacket is damaged, in which case the fibre sling should be discarded.
7.9.4
Fabrication yard slings are normally used repeatedly and are thus exposed to wear and tear. For
these slings, a wear factor of 1.2 should be used unless it can be demonstrated that the slings are in
good condition in which case a lower value can be used.
7.10
MATERIAL FACTOR
M
7.10.1
The material factor,
m
, should be taken as a minimum of 1.5 for steel wire rope slings and grommets
with certification in accordance with Section 15.2.
7.10.2
For as-new steel wire rope slings and grommets, a reduced material factor
m
of 1.35 may be used
subject to the certification requirements of Section 15.2.2.
7.10.3
For lifting with fibre slings, the material factor will depend on the material type and relevant failure
mode. Typically, the following minimum material factors
m
may be applied.
Polyester:
1.65
HMPE and Aramid:
2.0
Other fibre materials:
2.5
7.10.4
For fibre slings subject to a robust certification process, other material factors may be considered
acceptable; however, the material factor shall not be less than 1.65.
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