Unintentional selection of manual mode – DP incident

Comments from the report:

• Initiating event: Inadvertent selection of manual mode whilst in full DP mode
• Main cause: Human factor – The vessel mode of operation was changed from automatic DP mode to manual DP mode by a double press of the DP manual position button
• Secondary cause: Computer – No additional barrier (e.g. notification) when manual position selected

The vessel operator reported that there was an upgrade available to warn the DPO of the change of DP control status and therefore provide additional protection against accidental change of DP control status. The report concluded that all company vessels would be upgraded to include this function.

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

• It is important that DPO training focuses on good practice, an action should be followed up continuously to verify the intention of the action is reached or being executed
• This type of event has happened on other DP vessels, it is noted that some vessel operators have fitted a cover or made mode of operation buttons stand out from others
• The incident highlights the importance of vessel operators risk assessing the operation of the DP control station and taking appropriate action as required
• Consideration should always be given to using joystick auto heading, which can provide tighter control of the vessel, prior to switching to individual manual control of the thrusters