Procedures for ploughing using DP discussed

  • DP Event
  • Published on 29 November 2016
  • Generated on 14 December 2024
  • DPE 04/16
  • 2 minute read

Observation

The DPO was conducting too many concurrent tasks and they did not sufficiently monitor the vessel's speed.

DPE 16.04 – Procedures For ploughing using DP discussed – DP Observation – Flowchart

Comments

The report concluded that the DPO was conducting too many concurrent tasks so that he did not sufficiently monitor the vessel speed during the time the vessel was being controlled with JSAH.  

Further to this, company procedure/standing instruction have been changed so that changing the position of the targeted waypoint can be avoided except in the most necessary of cases.  

If it is found necessary to change the waypoint position, then the ploughing operation should be temporarily suspended by stopping the vessel and selecting automatic DP.

Considerations

  • It would be of considerable benefit if plough pulling forces, which can vary greatly, were fully integrated to the DP. It is not clear if this was the case and whether the direction of forces was interfaced.
  • It appears that a proper evaluation of the operation was not made: familiarity of the system is required together with adhering to company procedures.
  • A proper understanding of the relationship between position reference systems and forces is required.
  • Consideration should have been given to reduce speed to the operational minimum, the slower the progress of the plough the less effect it will have on the vessel’s positioning capability, as inertia becomes less effective.

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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