Method of and apparatus for mooring a floating structure

Abstract

A tension mooring system for a floating structure such as a drilling or production platform having a plurality of permanent mooring lines extending upwardly from a plurality of bottom anchors and terminating below the water level and having buoys connected to the upper ends thereof with sufficient buoyancy to maintain the upper end of the mooring lines in a generally vertical posture, replaceable mooring lines connecting from the buoys to the floating structure, the upper position of the permanent mooring lines being preselected to be below a highly corrosive area of the air-sea interface, and a pulling mechanism on the replaceable mooring lines to impart a preselected tension to the mooring lines, the bottom anchors being pre-positioned by drilling and cementing or driving piling through templates. The method of establishing a tension mooring system for a floating structure including the steps of placing a plurality of drilling templates on the bottom at the desired mooring site, drilling and cementing or driving anchor piles through the templates, lowering permanent mooring lines, remotely connecting them to the templates, connecting replaceable mooring lines from the floating structure to the buoys secured to the upper end of the permanent mooring lines, and tensioning the mooring lines to a preselected level.