Cooling pipe leak threatens main switchboard – DP observation

Comments:

A failure of a plug (old decommissioned cooling line for fridge compressors) on seawater cooling pipe for the Ac compressors resulted in flooding in the incinerator room (the water level was about 2cm depth) with small ingression of water in the engine control room on top of main 440V switchboard through a cable penetration.

The small water ingression (water dripping onto switchboard) was deflected by the design of the switchboard cover (class approved design) with a small quantity of water collecting on top. The quantity of water on top of the switchboard was so small that no immediate action was necessary to remove or control it during the incident. The top of the switchboard was dried after the leak was stopped and accumulated water had been removed from the incinerator room above.

Due to the desire to inspect inside the switchboard, with the vessel on standby but inside the .500m zone, the decision was taken to move outside the 500m zone as a precaution.

The vessel continued operations but remained outside the 500m.

Considerations from the above event:

• The good practice of moving outside the 500m zone is noted.
• Decommissioning of pipework by removal rather than plugging is the preferred method.
• With only one motion reference unit (MRU) on line its failure would affect the stability of all position reference systems selected to the DP system.
• Submission of DP observations, as learning opportunities, is much appreciated by members of the IMCA DP Focused Workgroup.