Page 87 - 6634
P. 87

Figure 6.8 - Relative hull responses of the three designs

                       During  the  concept  selection  phase,  efforts  are  concentrated  on  the  main

               dimensions  and  weights  under  the  consideration  of  design  standards  and

               performance requirements without a high degree of engineering detail. Finalized

               dimensions and main properties of the floating structures will be determined in the

               front-end engineering and design (FEED) stage through various analyses.

                      Floating  drilling  vessels  are  classified  in  two  basic  categories:  (1)  ship


               shape, e.g., drillships with hulls similar to ships and barges that are self- propelled
               or towed to location and (2) semisubmersibles (semis) (fig. 6.9).



                      6.2.1 Semi-submersible platforms


                      Concerning  the  group  of  the  mobile  offshore  structures,  the  semi-
               submersibles can be considered as typical offshore units .























                                                             87
   82   83   84   85   86   87   88   89   90   91   92