Computer Error Caused a DP Incident

Comments from the report:

The vessel engaged the support of the DP system manufacturer for investigation on completion of the operation. The OEM detailed that the DP controller had been corrupted by “non-valid” data received from the Position/Heading change menu on operator station No.1. Attempts to replicate the failure within the OEMs facilities were unsuccessful. The software was therefore modified in a way such that data packets received from position / heading move dialogue function would go through an additional check to avoid the scenario.

Considerations of the IMCA Marine DP Committee from the above event:

1. It would be expected that the DP control system manufacturer should issue a service bulletin for all systems and software versions that could be vulnerable to the same single fault. It is also noted that a very similar fault has been experienced by a member company involving the same DP system manufacturer.
2. The event report did not highlight the use of activity specific operating guidelines nor any change to DP status during the incident. Although not detailed in the report, the DP committee questioned the use of manual thruster control instead of Independent Joystick mode which may have aided station keeping during investigation works.