Incorrect entry of DP rotation point offsets
- DP Event
- Published on 18 September 2023
- Generated on 26 December 2024
- DPE 03/23
- 2 minute read
Incident
A vessel was engaged in Driving and ROV work over a live manifold. Due to rising currents the vessel was required to change heading.
Overview
A vessel was engaged in Driving and ROV work over a live manifold. During ROV dive the vehicle had taken receipt of a hot stab connected to a recently deployed downline with the intention of connecting the downline to the manifold on the seabed to enable de-watering of the pipeline.
Due to rising currents the vessel was required to change heading, with a move agreed between Bridge and Dive Control to pivot around the over boarding chute housing the downline deployed to the worksite, such to minimise disruptions to the works being carried out subsea.
The move required was a heading change of around 30 degrees with the chute location known to be approximately: 25m Astern and 11.5m Port from centre ship. An input error from the operator occurred and the DP system was instructed to rotate 30 degrees on a point 25m Forward and 11.5m Port from centre ship.
During the move the ROV reported that it was losing position and an ‘All Stop’ was called to the move. It was then discovered by the DP Operator that the input error had occurred, and the vessel was returned to its desired position prior to re-commencing the work scope.
Figure one – Desired heading change move
Figure two – Actual heading change/vessel move
Observations
- ASOG/CAMO was in operation at the time of incident.
- At no point did vessel lose control, DP system (correctly) responded to input command (which was incorrect).
- the DP operator stopped the move immediately upon becoming aware.
- Vessel operating in DP Class 3 configuration. At no point was DP compromised or at risk (according to duty holder).
- Once the move was stopped, the correct inputs were entered, and vessel moved to the desired location and heading.
- The principles of Bridge Resource Management, including cross checking, have been reinforced with the DPOs. The CAMO/ASOG and Master’s Standing Orders now include this.
- New Master Standing Orders for DP Operations have been rolled out. These emphasis cross-checking, DPO teamwork and focus during operations.
Latest DP incidents
-
Prepare for 2025 solar activity
This case study covers events that occurred on the same vessel, eight months apart.
DPE 02/24
29 July 2024
Undesired event
-
Know your vessel capabilities and when to stop!
An incident that occurred on an equipment class 2 MODU, during well intervention operations.
DPE 02/24
29 July 2024
Incident
-
Duty/not duty, which is the question?
With no steering control of the port azimuth thruster, and no other thrusters operational, the heading of the FPU could not be maintained.
DPE 02/24
29 July 2024
Undesired event
-
You’ve got the ASOG, so now you’ve got to follow it
This case study examines an incident that occurred on an equipment class 2 MODU, during well intervention operations.
DPE 02/24
29 July 2024
Incident
-
Button trouble
A Dynamically Positioned vessel experienced a loss of Dynamic Positioning (DP) control while installing cable within a wind farm.
DPE 01/24
3 April 2024
Incident
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.
Any queries should be directed to DP team at IMCA. Share your DP incidents with IMCA online. Sign-up to receive DP event bulletins straight to your email.