Appraisal of ropes for LNG moorings
The movement of the Uquified Natural Gas (LNG) mar1c.et to larger vessels has meant that larger and , more exposed offshore terminals are now employed. This presents challenges for the ropes which are used as mooring lines for these vessels. A programme to appraise the suitability of mpes for the mooring application is reported. It induded assessment of: strength; operation over ship's fair1eads; tensile fatigue performance and creep rupture behaviour (the latter is of particular relevance in hot dimates). The programme was defined so as to model as closely as possible the service conditions which will be encountered. The paper describes the assessment criteria and reports a substantial body of wor1c. undertaken on mpes made using different fibres with a view to assessing their suitability for service in the challenging application of LNG moorings. The results of the study show that whilst HMPE mpes will perform very satisfactorily in cooler ambient conditions, at raised temperatures creep becomes an issue. In these situations aramid fibre mpes offer a better overall performance.
Author(s): I.M.L. Ridge, P. Wang, O. Grabandt and N. O'Hear