Pipe leak leads to loss of all thrusters
- DP Event
- Published on 29 November 2019
- Generated on 22 February 2025
- DPE 04/19
- 2 minute read
Incident
Whilst pressurising the fire main for helicopter operations, a gasket failure occurred on the pipework valve under the engine room floor.
Comments
Whilst pressurising the fire main for helicopter operations, a gasket failure occurred on the pipework valve under the engine room floor in front of transformers 690V/440V T3 and T4. The spray created a water fog and favourable atmosphere for an electric arc on T3 and T4 transformers, leading to a loss of 440v and 230v on vessel power plant. Upon depletion of the UPS batteries, the thrusters were lost.
A detailed investigation was undertaken with many findings including adding ingress protection at the transformers, adding isolation valves in the piping, and modifying procedures.
One supplementary finding related to the UPS systems, as both failed before 30 minutes. Investigation revealed that the load on the UPS’s was greater than when they were tested alongside during annual DP trials.
Considerations
- It was questioned whether the DP alarm should have been yellow rather than blue and it is assumed that, for some reason, the alarms generated at 08:13 were not interpreted correctly.
- There was concern that a fire main was passing through a transformer space. It was considered that if the vessel had been equipment class 3, it would have been subject to an assessment of the space so the danger of such an occurrence happening would have been noted.
- UPS battery endurance tests (30min check) should be performed with all UPS consumers connected and in use.
Latest DP incidents
-
Thorough preparation is key
With 4 of 8 diesel generators running and connected to a closed ring bus, and 7 of the 8 thrusters selected to DP, a DP equipment class 3 MODU was set up in Green mode whilst on standby.
DPE 03/24
5 November 2024
Incident
-
There – but not really there
This DP event occurred on a DP equipment class two supply vessel whilst carrying out cargo operations on the starboard side alongside the asset and working at the lee side in the drift-off position.
DPE 03/24
5 November 2024
Incident
-
Equipment Class 3, even if you operate as 'Class 2'
This case study examines a DP incident on an equipment class 3 multi-purpose vessel while operating in good conditions.
DPE 03/24
5 November 2024
Incident
-
Line of sight
This case study covers events onboard a DP equipment class 2 vessel whilst holding position in a turbine field, with three position reference systems selected into DP – DGPS, HPR and Fanbeam.
DPE 03/24
5 November 2024
Incident
-
DP Drill Scenario
DP emergency drill scenarios are included to assist DP vessel management, DPOs / Engineers, and ETOs in conducting DP drills onboard.
DPE 03/24
5 November 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.