0027/nd guidelines for Marine Lifting and Lowering Operations

17.3 
POSITION OF BUMPERS AND GUIDES 
17.3.1 
The position of bumpers and guides shall be determined taking into account acceptable support points 
on the module. 
17.3.2 
Dimensional control reports for the as-built bumper and guide system shall be reviewed to ensure fit up 
offshore. 
17.3.3 
Nominal clearances between bumpers/guides and pins/buckets shall be +/-25mm to account for 
fabrication and installation tolerances. These may be reduced based on trial fits and/or a stringent 
dimensional control regime. 

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GUIDELINES
 
FOR
 
MARINE
 
LIFTING
 
&
 
LOWERING
 
OPERATIONS 
0027/ND Rev 11 
 
Page 60 of 84 
17.4 
BUMPER AND GUIDE FORCES
17.4.1 
For offshore lifts, bumpers and guides should be designed to the following forces (where W = static 
hook load) unless dynamic analyses are performed to justify alternative values: 
Table 17-1 
Default Bumper & Guide Forces (Offshore) 
Lifting onto: 
Fixed 
platform 
Floating 
unit 
Own 
deck 
Vertical sliding bumpers 
Horizontal force in plane of bumper: 
0.10 x W 
0.20 x W 
0.05 x W 
Horizontal (friction) force, out of plane of bumper: 
0.05 x W 
0.10 x W 
0.025 x W 
Vertical (friction) force: 
0.01 x W 
0.02 x W 
0.005 x W 
Forces in all 3 directions shall be combined to establish the worst design case 
Pin/bucket guides 
Horizontal force on cone/end of pin: 
0.05 x W 
0.10 x W 
0.025 x W 
Vertical force on cone/end of pin: 
0.10 x W 
0.20 x W 
0.05 x W 
Horizontal force in any direction shall be combined with the vertical force to establish the worst 
design case.