Patent ID: 7452162

Claim:
An installation method for a tension leg platform and first and second preassembled mooring tendons in a body of water, the tension leg platform ( 10 ) characterized by a buoyant hull ( 14 ) that defines first and second extremities ( 16 ), two or more vertical columns ( 20 ) each having a lower end carried by and fixed to the hull and an upper end, a superstructure ( 28 ) carried by the upper ends of the two or more vertical columns, and first and second tendon connection sleeves ( 22 ) fixed to the first and second extremities ( 16 ) of the hull respectively, the first and second preassembled mooring tendons ( 12 ) each characterized by a lower end terminating with a lower connector ( 120 ) arranged for mating with a subsea anchoring structure ( 50 ) and an upper end having a tip ( 26 ) and an upper connector ( 27 ) arranged for connecting to one of said first and second tendon connection sleeves ( 22 ), the method comprising the steps of: positioning an assembly vessel near said tension leg platform ( 10 ); vertically suspending said first preassembled mooring tendon ( 12 ) in said body of water by a flexible first tension member ( 100 ) connected between said tip ( 26 ) of said first tendon and said assembly vessel; disposing a first tension device ( 101 ) on said tension leg platform ( 10 ); routing a flexible second tension member ( 102 ) through said first tendon connection sleeve ( 22 ) and connecting an upper end of said second tension member ( 102 ) to said first tension device ( 101 ) and a lower end of said second tension member ( 102 ) to said tip ( 26 ) of said first preassembled mooring tendon ( 12 ); then tensioning said second tension member ( 102 ) by said first tension device ( 101 ) to support said first tendon ( 12 ), slacking said first tension member ( 100 ), and disconnecting said first tension member ( 100 ) from said first tendon ( 12 ); positioning said lower connector ( 120 ) of said first preassembled mooring tendon ( 12 ) above said subsea anchoring structure ( 50 ); lowering said first preassembled mooring tendon ( 12 ) by said tension device ( 101 ) and said second tension member ( 102 ) so that said lower connector ( 120 ) of said first preassembled mooring tendon ( 12 ) mates with said subsea anchoring structure ( 50 ); and locking said lower connector ( 120 ) of said first preassembled mooring tendon ( 12 ) to said subsea anchoring structure ( 50 ).