A bulk carrier was on a ballast passage and conducting ballast exchange operations when a large gate valve in the engine room on the ballast/bilge system failed, causing severe flooding. Further flooding occurred when the crew attempted to de-ballast and trim the ship, until eventually the flooding in the engine room was more than eight metres deep. Having lost all propulsion and electrical power, the vessel had to be taken in tow as a salvage operation.
Wrong adjustment of ship ballast actuators
The valve failed due to a high pressure surge, possibly caused by other hydraulically operated valves in the ballast system closing too fast, as their actuators were out of adjustment;
On this ship, it was regular practice to press up tanks above full capacity, imposing very high loads on tank boundaries and associated valves and piping;
Further flooding during attempts to control the situation was caused by insufficient knowledge of the ballast system on the part of the crew;
No ballasting procedures had been developed for the ship;
Poor communications between bridge and engine room personnel during the crisis.
Best practice when ship ballasting
The ship’s staff must have a thorough knowledge of the vessel’s tanks and piping systems. Drawings of these systems must be correct and readily available on board.
The principles of bridge resource management (BRM), such as consultation and cross-checking, are equally applicable to engine room operations, particularly during an emergency.
The ship must have established procedures (as required by the ISM Code) for safely conducting routine operations such as exchanging ballast. These must be known and followed.