Rip tide presents problems
- DP Event
- Published on 2 June 2017
- Generated on 2 October 2026
- DPE 02/17
- 1 minute read
Observation
A degraded performance was caused by a rip tide. All DP checks were carried out, and the system's performance was monitored for 20 minutes.
Comments
It was a single rip tide and when it had passed the vessel was set up back in automatic position mode.
There was clear evidence that a degraded performance was caused by the rip tide. A risk assessment was made, all DP set-up checks were carried out and the DP system performance was monitored for 20 minutes.
Other rip tides were not observed and the vessel approached the installation to resume operations.
Considerations
- The observation demonstrates a positive attitude to observing environmental conditions with respect to vessel capability and taking the correct actions to avoid potential dangerous loss of position.
- It is unreasonable to expect any DP system to cope with the sudden change in forces that can be introduced by rip tides which can have a catastrophic effect on the ability of a DP system to maintain position and heading.
- If this was a DP equipment class 2 operation then the report indicates that there was inadequate redundancy with regards to position reference systems.
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