Comments from the Report
The heat exchange system is poorly designed and without redundancy for half of the switchboard. Design flaws were compounded by the introduction of turbidity and silt into the cooling system. The vessel was idle for some time in shallow water and the systems were not adequately preserved. There was biological fouling taking place on the heat exchangers. Although multiple heat exchanger cleanings had occurred, the system was not adequately flushed to remove the fouling.
Considerations of the IMCA Marine DP Committee from the Above Event
- The report indicates that although the cooling systems were cleaned prior to reactivation they had not been properly flushed and were therefore unable to perform to full capacity.
- It is important that all redundant systems are able to perform to full capacity following loss of a redundant group. If not, there is a potential to exceed the WCFDI following a failure.
- Performance tests should be part of the reactivation procedures after an idle period in shallow water.