The Finnmaster, a ro-ro cargo ship registered in Finland, caught fire in the auxiliary engine room in September 2021 as it was departing the UK port of Hull.
With assistance from the Safety Investigation Authority Finland, the MAIB is looking into this accident. Simon Graves, our investigation’s lead inspector, outlines an important preliminary safety finding that has already had a significant effect on the maritime sector:
The onboard fixed fire extinguishing system was turned on by the crew in an effort to put out the fire by injecting carbon dioxide (CO2) into the machinery areas.
Each of the 42 cylinders’ 45kg of CO2 capacity was intended to be discharged into the engine room via the mechanism.
Barely 21 of the cylinders actually triggered, which meant that only half of the necessary amount of CO2 was delivered into the space.
Fortunately, the crew was able to put out the fire without any injuries, but the CO2 system’s partial failure could have had much worse effects.
Early on in the MAIB inquiry, it became clear that a blockage in a few of the flexible hoses, which transport CO2 to the valves on the cylinders to open them when the system is triggered, caused a partial failure of the fixed CO2 fire extinguishing system.
A manufacturing flaw in some of the hose assembly couplings that had impeded the flow of CO2 through the system was discovered after a thorough analysis of the flexible hoses installed in the system.
More than 33,000 hose assemblies likely came from the same supply chain and were installed on ships all over the world, with a small number of them possibly sharing the same manufacturing flaw, according to the investigation into the origin of the hose assemblies, which were installed earlier this year.
Early in 2022, we released safety notice 1/2022, which described the discovered problem with the CO2 system on Finnmaster and advised recipients of the hose assemblies in question to examine their systems to make sure they are completely functional should they be needed in an emergency.
Additionally, we asked that any results be relayed to us so that we could determine the severity of the problem.
The MAIB has received a number of encouraging reports of findings in fixed fire extinguishing systems afflicted by the same issue since the safety bulletin was released.
In one instance, a huge drill ship authorized to carry 200 people had five damaged hoses.
There may have been serious casualties and catastrophic repercussions in the event that the fixed CO2 firefighting apparatus on board this vessel had malfunctioned.
We are still receiving replies to the safety bulletin, therefore we are urging any businesses who have not yet done so to indicate that they have taken prompt corrective action to locate and clear any clogged pilot hose assemblies on the impacted CO2 fire extinguishing systems.
Graham Wilson, the investigation’s principal inspector, continues:
The results of the intricate technical inquiry into this accident being conducted by the MAIB will be released soon.
However, one important aspect of the MAIB’s responsibility is to issue urgent safety bulletins like this one to warn the industry of severe safety risks as soon as they are found and to recommend that organizations take prompt appropriate action.
The usefulness and significance of these safety warnings are highlighted by the fact that this particular bulletin was successful in detecting and resolving a safety-critical issue on other ships.
It exemplifies how efficient the MAIB is at preventing other accidents.