Fabrication and Installation - Offshore Structures: Design, Construction and Maintenance - page 337

FIGURE 5.27 Transport of the topside to the barge.
sling load and a horizontal force equal to 5% of this load, applied perpendicular
to the padeye at the center of the pinhole. All these design forces are applied as
static loads if the lifts are performed in the fabrication yard.
On the other hand, if the lifting derrick or the structure to be lifted is on a float-
ing vessel, then dynamic load factors should be applied to the static lifting forces.
In particular, for lifts made offshore, API RP2A recommends two minimum
values of dynamic load factors, which are 2.0 and 1.35. The factor 2.0 is to be
considered in designing the padeyes as well as all members and their end con-
nections framing the joint where the padeye is attached, while the factor 1.35 is
to be used in designing all other members transmitting lifting forces.
For load-out at sheltered locations, the corresponding minimum load factors
for the two groups of structural components become, according to API RP2A,
1.5 and 1.15, respectively.
Figure 5.27 shows lifting of the deck to start pullout onto the barge.
Lifting terminology is summarized in Table 5.4 .
5.8.1 Lifting Calculations
For any lifting requirement, the calculations carried out should include the fol-
lowing allowances, factors and loads or equivalent weight contingency factors,
as already discussed.