When dimensioning SPM offloading buoy systems it is important to know all possible forces acting on the system and how these forces are distributed through the mooring lines. If this distribution is analyzed, a minimum strength (after some safety factors are taken into account) for mooring lines and foundation can be applied.

After all forces acting on SPM offloading systems are known, engineers can start with dimensioning. First a decision has to be made about the type of mooring line. This choice is influenced by economics, environmental conditions, availability, requirements and other installations within the area. When the type of mooring line is chosen, the minimum length of this line can be calculated. Secondly a decision has to be made for the type of foundation system. This decision mainly depends on seabed conditions and force resistance.

To give engineers an indication of the forces acting in the mooring lines, a simplified method to calculate these forces can be used. Further information about forces, dimensioning mooring lines, foundation types and safety factors can be found in the pdf file: