Operators that fail to properly monitor ballasting operations risk catastrophic flooding according to an accident investigation report published by the Australian Transport Safety Bureau.
The failure to close a valve to the aft peak ballast tank onboard the CSL Australia-owned 15,999 dwt cement carrier Goliath during ballasting resulted in water leaking into a holed scupper line which drained into the steering gear room bilge well, causing the steering gear room to flood to a depth of around 10cm.
The vessel, which had been taking on ballast as part of a ballast water exchange The vessel reached its original destination of Devonport around five hours after the incident on 7 March. Repairs were effected including renewal of the CO2 room drain line and the mending of deck and bulkhead penetrations.
The investigation found that onboard the vessel there was no system for logging or tracking the status of manually operated valves in the ballast system. This meant the ballast control panel did not show the status of the valves when they had not been closed. The sailing had been disrupted by a delayed departure and training sessions during the voyage, which resulted in crew shifts being changed. ATSB said that “disruption of normal routine, increased workload and changes of shift personnel increased the potential for error”.
The vessel has since had a ballast water management system fitted, meaning it no longer needs to conduct ballast water exchange. The ballast tank remote sounding and alarm system, and ballast tank steelwork (including piping in the aft peak tank), have also been replaced.
Procedures were also changed, requiring the duty officer to log all manual valve operations. Ballasting of the aft peak tank is conducted during daylight only. A status tracking board was made for the manual valves with moveable pegs showing whether each valve was open or closed.