Comments from the report:
A new gyro was installed as a replacement but failed to start with first attempt. Further investigation revealed that the ‘Gyro 2 remote control unit’ located on the forward bridge had a fault, failure of it caused Gyro 2 to shut down. When the ‘Gyro 2 remote control unit’ was disconnected the new gyro was switched on with no further problems. After a stabilisation period the Gyro was tested, found operational and the signal to DP reinstated. DP operations were resumed. In conclusion the original Gyro 2 was and remains healthy.
Considerations of the IMCA Marine DP Committee from the above event:
- It can be assumed that good operational activity planning took place and the ASOG indicated a yellow alert to be activated with the loss of one gyro
- The logic of systems connected to the DP system need to be fully understood so that a failure in one part of a connected system does not affect the DP system
- With the availability of so many position reference systems it may be better to use 2 DGNSS and keep the other 2 DGNSS as monitoring
- It is unclear what the gyro 2 remote control unit is required for, but it appears to have introduced an additional failure mode of the gyro and should have been identified in the DP FMEA.
The following case studies and observations have been compiled from information received by IMCA. All vessel, client, and operational data has been removed from the narrative to ensure anonymity.
Case studies are not intended as guidance on the safe conduct of operations, but rather to assist vessel managers, DP operators and DP technical crew in appropriately determining how to safely conduct their own operations. Any queries should be directed to IMCA at [email protected]. Members and non-members alike are welcome to contact IMCA if they have experienced DP events which can be shared anonymously with the DP industry.
IMCA’s store terms and conditions (https://www.imca-int.com/legal-notices/terms/) apply to all downloads from IMCA’s website, including this document.
IMCA makes every effort to ensure the accuracy and reliability of the data contained in the documents it publishes, but IMCA shall not be liable for any guidance and/or recommendation and/or statement herein contained. The information contained in this document does not fulfil or replace any individual’s or Member's legal, regulatory or other duties or obligations in respect of their operations. Individuals and Members remain solely responsible for the safe, lawful and proper conduct of their operations.