GUIDELINES FOR MARINE LIFTING & LOWERING OPERATIONS 0027/ND Rev 11 Page 82 of 84 B.1.4
The derivation of loads to the lift points is to be based on the most conservative location of the CoG
envelope (see Section 5.2.1). Based on a rectangular CoG envelope, the plan view on the lift points
and CoG envelope is as shown in the following Figure B-2.
Figure 19B-1 Derivation of Tilt Factor for CoG Below Lift Points Elevation on Two Crane Lift – Tilt for Maximum Tilt Effect Factor for Crane #1
p1 & p2
x
x
Enlarged Detail of
CoG Envelope -
Elevation
z
z
C/L CoG Envelope
a
b
q1 & q2
r1 & r2
s1
&
s2
c
d
L
CRANE #1 CRANE #2 CoG Envelope
Lifted Structure
[L*cos α] + [(b-a)*sin α]
CRANE #1 CRANE #2 [(b+z)*sinα] + [(d+x)*cosα]
r
h
α
[L*cos α] - [(b-a)*sin α]
CRANE #1 CRANE #2 [(a+z)*sin α] + [(c+x)*cos α]
Elevation on Two Crane Lift – Tilt for Maximum Tilt Effect Factor for Crane #2
s
Elevation on Two Crane Lift –No Tilt Giving Reference Dimensions
h
α
Lift Points 1 and 4 Lift Points 2 and 3 See Figure B-2 for plan details of CoG envelope 11
