The increasing use of composite materials instead of steel in ships poses a significant fire threat and will require a new approach to safety, according to a Danish study.

Composite materials are increasingly viewed as a possible way to achieve a new generation of super-lightweight, fuel-efficient ships as the industry seeks to reduce its carbon footprint.

The European Union-funded Realisation and Demonstration of Advanced Material Solutions for Sustainable and Efficient Ships (RAMSSES) project is leading the way and hopes to use fibre-reinforced plastics (FRP) to halve the weight of hulls in the future.

“The new hulls will do more than simply save shipbuilding resources. Ships will also be less expensive to operate, due either to lower fuel demands or to greater cargo capacity,” RAMSSES said.

Catastrophic fire

However, a catastrophic fire in 2015 on the 217-gt crew transfer vessel Umoe Ventus (built 2014) prompted an investigation into the potential hazards of the composite materials.

Denmark’s OSK-ShipTech and the Danish Institute of Fire and Security Technology used the Umoe Ventus blaze to examine the human element and technical aspects of these materials and develop a holistic approach to the fire threat.

The study, backed by the Danish Maritime Fund, was aimed principally at high-speed craft but the findings could equally apply to the emerging generation of merchant ships using composite materials.

The study's project manager, Anders Dragsted, said: “The Umoe Ventus accident was a clear example of the fire risks related to the lightweight composite vessels of the future.

"The purpose of this project is to rethink and strengthen firefighting onboard especially exposed FRP vessels, by developing new guidelines for fire prevention, based on experience from the Umoe Ventus accident.”

The examination of 45 marine accidents related to composite materials uncovered a "lack of knowledge" about their use in the shipping industry, particularly the materials' performance in fire.

FRP vessels present a fire risk that does not exist with steel hulls. Areas commonly viewed as low risk, such as voids and open spaces, are actually the third most common areas for fire on such ships. Contact with hot surfaces or fluids is the most common cause of FRP fires and represents a risk factor that does not exist with steel hulls.

Fires involving FRP also often follow an “unforeseen scenario” that prevents crew from successfully extinguishing them and requires crew to “adapt and be creative”.

The OSK-ShipTech report recommends that the fire response plan on FRP vessels should be “ship specific”.

The exact properties of the material used in construction should also be considered in mustering and evacuation plans that account for the faster development of fires with FRP.

It proposes passive fire-prevention measures such as insulation as the preferred fire-protection measure on vessels made of composite materials.

The investigators also suggest that water spray extinguishing systems should be preferred to gas systems to put out fires in an emergency, and crew fire response training should not be based on steel construction ships.