- Discover how we are helping Members reduce emissions: Explore the ProjectGHG hub now.
- Join the global DP Community at the IMCA DP Conference in Amsterdam. 21 and 22 May. Book now
- Register your interest for the IMCA Global Summit 2024. 3-4 December, Utrecht, Netherlands.
- Now booking. Underwater Ship Husbandry Seminar. 10 October 2024, Singapore.
Unreliable position reference systems leads to DP incident
Comments from the report
Only 2 DGNSS were online, with poor signal quality due to the location and environmental conditions. The end effect was that the deviation from the set point in surge and sway were increasing for each oscillation.
Considerations of the IMCA Marine DP Committee from the above event
- For DP2 operations, the use of only 2 DGNSS systems is insufficient; a minimum of 3 systems are to be used based on 2 principles.
- The importance of monitoring the position reference systems (PRS) screen cannot be overstated; this then ensures that all the PRS agree on the position of the vessel.
- It is evident that the selected PRS were not providing reliable position information and highlights the problems that can be experienced when at least one reliable PRS is not available.
- It was noted that the move was paused at 2005; this should have provided the opportunity to investigate and correct the situation rather than continue with the move.
- It is also worth considering that the erratic movement of the vessel could indicate that the DP system needs retuning.
DP Event
Published: 29 November 2019
Download: 
IMCA DPE 04/19
Submit a Report
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.
IMCA’s store terms and conditions (https://www.imca-int.com/legal-notices/terms/) apply to all downloads from IMCA’s website, including this document.
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.