Platform motion was reduced to three degrees of freedom by applying vertically, prestressed cables anchoring the platform to the sea bottom. Forces in the anchor cable and the horizontal movement (surge) for three different, triangular shaped platforms were investigated. A fourth platform design was then developed using a stabilizer and combining the best characteristics of the initial three units. Realistic platform parameters were used: operating weight 10,000 tons, total buoyancy 14,500, cable pretension 1500, triangle side length 80 meters, deck level above SWL 18 meters, weight in light condition 6000 tons and metacentric height 10 meters. Theoretical and experimental results showed good agreement; total drag was negligible compared to inertia forces; pretension in the mooring cables has little effect on dynamic mooring forces; platform geometry is of great importance for the dynamic mooring forces; the stabilizer was very effective for the optimized wave period and dynamic mooring forces can be reduced by increasing the side length of the platform.

Media Info

  • Pagination: p. 277-297

Subject/Index Terms

Filing Info

  • Accession Number: 00095028
  • Record Type: Publication
  • Source Agency: Arctic Institute of North America
  • Files: TRIS
  • Created Date: May 19 1975 12:00AM