AMOG was contracted by to undertake a range of studies relating to the integrity of the mooring component of CWLH RTM mooring system. The RTM mooring system has been installed in 1996.
During inspections in late 2009, significant loss of material was found on some links of the thrash zone mooring chains. AMOG undertook the following:
- Development of methodologies to use nonlinear elasto-plastic finite element models to predict the remaining strength and remaining fatigue life of the eroded links
- FE analyses of links based on assumed material losses as well as on chain link geometry derived from detailed photogrammetry of the damaged links
- Predictions of remaining mooring leg strength based on continued operation for different periods
- Preparation of the formal analysis reports which were submitted to ABS for approval
In addition, AMOG undertook further studies to develop the Mooring Integrity Management System for the RTM column and mooring legs. This work included:
- Performing a detailed risk evaluation of the RTM column and mooring system
- Performing detailed criticality assessments of all identified locations based on available inspection data and design calculations
- Developing a database of critical design information for use by the Mooring System Technical Authority
- Development of the overall inspection strategy and specifications for both external and internal inspections
- Development of detailed inspection work packs for external and internal inspections