MAIB issues safety warning after discovery of blocked fixed CO2 fire extinguishing system pilot hoses

Picture for illustration purposes
Picture for illustration purposes

On 19 September 2021, a fire broke out in the auxiliary engine room on board the Finland registered roll-on/roll-off cargo ship Finnmaster while departing Hull. In an attempt to extinguish the fire, the ship’s crew activated the machinery space’s carbon dioxide (CO2) fire extinguishing system, but only half of the system’s gas cylinders opened. The initial investigation identified that one of the CO2 system pilot hoses was blocked due to a manufacturing defect. Several coupling leaks were also found in the pilot lines.

Safety Issues

– The quality assurance processes of the pilot hose assembly supplier failed to identify that the hose couplings had not been fully bored through
– The onboard installation testing processes did not identify that some of the hose assemblies were blocked and that there were leaks in the CO2 system pilot lines
– Latent defects may exist in the CO2 fire-fighting systems on board ships supplied with potentially affected hose assemblies delivered from the same batch


Geeve Hydraulics B.V. has been recommended (S2022/105) to provide a copy of the MAIB safety bulletin to all customers supplied with the affected hose assemblies, and draw attention to the safety issues and the need for immediate action. It has also been recommended (S2022/106) to amend its procedures to ensure that hose assembly components are procured in accordance with the relevant type approval requirements.

All companies identified as having been supplied with the affected hose assemblies by Geeve Hydraulics B.V. have been recommended (S2022/107M) to take immediate remedial action.

Request for information
To assist this investigation, it is requested that service providers, owners and operators pass details of any blocked pilot system hose assemblies that they find to us.

Download the safety warning: MAIB Finnmaster Safety Bulletin

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