This technical paper addresses the value of regulatory requirements to recover and test 15-meter inserts from polyester mooring systems for production systems in the Gulf of Mexico. The authors have been working on a MMS-sponsored project to determining the Accuracy of Polyester Subrope Damage Detection by ROV Inspection, and Assessment of Remaining Rope Strength and Life.
Typical samples of subropes used to comprise 15-meter mooring rope inserts for polyester-based mooring systems have been exposed to the equivalent cyclic motions of 20 Hurricane Katrinas, and then the ropes were tested to failure. Results were compared to tests results from the same subropes not exposed to 20 Katrinas. There appears to be little if any rope decline in rope integrity, even if one Katrina-type hurricane scores a direct hit each and every year for the 20-year life of the mooring system.
Ayers, R.R., O’Hear, N., “Polyester Moorings: Is Insert Recovery and Testing the Best Way To Determine Rope Integrity?,” OTC 19198, Presented at the 2008 Offshore Technology Conference, May 7, 2008, Houston, Texas.