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Good practice following system self-test alarm – DP observation

Comments from the report:

The error was traced to a serial interface module for DP Controller A and confirmed that the red error lamp on this module was illuminated.  Whilst indicating an error, the module was still performing correctly in so far as there was no effect with its data feeds.  The decision was made to replace the module with a new one, dive control was requested to recover the bell to surface and hold it there whilst replacement was carried out.

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

  • The actions taken were all in accordance with good practice.
  • 40m water depth only provides for a small envelope for seabed based position reference systems (PRS).
  • In these depths of water, it is advisable to make use of surface based PRS, in this instance DGNSS was used.

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.