DNV GL Warns on Container Ship Fires
DNV GL has issued a warning on container ship fires, highlighting a recent example that demonstrates the importance of inspection and maintenance of fire-fighting equipment:
Course of events
A fire was detected inside one of the forward cargo holds on a fully-loaded container ship. Direct access to the fire was impeded due to its location at mid-height in the hold with containers stacked on hatch covers.
Fire-fighting commenced using the water drenching system supplied by the port and starboard fire main lines, connected to nozzles beneath the hatch covers. This was hampered due to leaking pipe expansion joints, rendering one side out of action.
The CO2 system was engaged, but the line was also found to be leaking at pipe and valve flanges in the CO2 room and in the under deck passageway, preventing total flooding of the hold with CO2.
The crew also attempted to provide additional water via fire hoses through gaps in hatch covers from the main deck. First attempts were hindered, as the fire hose couplings had a different diameter to the hydrant couplings dedicated to the drenching system.
However, the crew managed to contain the fire until it was finally extinguished at port. The vessel was detained by the port authorities, and the incident was subject to investigations by several parties, including the flag state.
Extent of damage
The cargo hold transverse bulkhead structures had locally buckled, and nearby electrical fittings were burned. There were no casualties or personal injuries reported.
Several adjacent containers in the cargo hold were damaged by heat, smoke and water. The vessel’s schedule was significantly interrupted, delaying the delivery of high-value goods.
Probable causes
The fire is thought to have started in a container carrying dangerous goods, possibly of an explosive nature. The actual goods were most likely not declared, leading to improper stowage and segregation.
The leaking fire line was probably due to a combination of deficient axial support or stoppers and misaligned pipes outside the coupling manufacturer’s recommended tolerances.
Leakages of CO2 at the flanges of the CO2 pipes and fittings could be the result of poor workmanship and wrong practices during installation. Gaskets of a different pressure rating and multiple gaskets to compensate excessive gaps were also found in several flange joints.
The CO2 line’s remote control valves were dismantled after the incident and found to be contaminated with entrapped water containing foreign particles. The valve adjustment nuts were set, but apparently in a position restricting the maximum flow rate of CO2.
Recommendations
As an immediate preventive measure, DNV GL recommends a critical review of onboard maintenance and inspection programs concerning fire protection systems and appliances.