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Bad connection causes loss of DGNSS – DP observation


After all the checking, it was found that there was water ingress at the L-Band connector to the antenna on the mast. This was dried and cleaned. The connectors were properly sealed with self-bonding electrical tape and cable ties.

Considerations from the above event:

  • This observation reinforces the need for good practice conducting field entry/arrival DP checks making sure all DP systems are operational and healthy.
  • It is unclear why the laser-based reference system was not in use but it is assumed the system was not immediately available due to distance or shadowing.
  • Several recent reports indicate the use of only two enabled position reference systems (PRS), these are often both DGNSS. It cannot be stressed enough that a mixture of PRS should be used.
  • Regular checks of connections which are exposed to the environment need to be carried out and included in planned maintenance systems.

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.

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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.