GUIDELINES
FOR
MARINE
LIFTING
&
LOWERING
OPERATIONS
0027/ND Rev 11
Page 46 of 84
13.5
LOAD CASES
13.5.1
Load cases for fabrication yard lifts should be based on the general guidelines in Sections 5 to 9 and
11 to 12.
13.5.2
For multi-crane operations, a sensitivity analysis with respect to possible crane load distributions (see
Section 13.3.2) should be carried out.
13.5.3
For
roll-ups, the analysis should be carried out to include an adequate number of roll-up angles.
Where it is noted that there is the possibility for higher loads in the rigging system, higher stresses in
the lifted structure etc. to occur
between the angles selected, then intermediate
steps between the
selected angles should be considered.
13.6
LIFTING EQUIPMENT
13.6.1
Slings and grommets should be designed based on the requirements of Section 7.
13.6.2
Attention should be paid to the effect of object rotation (roll-up) on sling connections.
Additionally, the
effect of any unequal load distribution in the legs of slings should be considered if the structure rotates
about the sling eye or a doubled sling (see Section 5.8.2).
13.6.3
Shackles with a WLL
50 tonnes without
certification may be accepted, provided:
a)
the WLL is stamped on the shackle
b) the original manufacturer is recognised
c) calculated dynamic shackle load
WLL
d) the shackle is thoroughly inspected before use
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