Following a track on DP causes power issues

  • DP Event
  • Published on 10 August 2017
  • Generated on 13 December 2024
  • DPE 03/17
  • 1 minute read

Incident

Chosen settings of gain, corridor limits, rate of turn and speed of the vessel could all have contributed.

DPE 17.03 – Following a track on DP causes power issues – DP Incident – Flowchart

Comments

  • The initiating event was a sudden increase of propulsion to full ahead.
  • The main cause was attributed to the computer with unexpected thrust allocation.
  • The secondary cause was human factor due to a slow reaction to switch to manual mode.

Considerations

  • This is an extremely deepwater operation, although margins are large, DP control is still desirable.
  • The limitation of using DGNSS as the only position reference system should be known and acknowledged by those involved in the operation.
  • From the information available it would seem this could be an operator initiated problem. Chosen settings of gain, corridor limits, rate of turn and speed of the vessel could all have contributed.
  • The operator could have selected the ‘Stop’ function on the DP console to stabilise the situation, instead of selecting joystick.
  • It is important that instructions for switchboard configurations are supplied and followed.
  • The starboard propeller tripped at 100% load; this should not happen.

The case studies and observations above 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 technical crew.

IMCA makes every effort to ensure both the accuracy and reliability of the information, but it is not liable for any guidance and/or recommendation and/or statement herein contained.

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