A fire in a ro-ro space can grow intensely large and statistics show that the number of fire accidents in these spaces are not decreasing over the last years. The different types of ro-ro spaces defined in SOLAS has different requirements for fire extinguishing systems, natural and mechanical ventilation and fire detection system. RO5 aims to clarify how the ro-ro space ventilation affects the development and management of a fire and to recommend appropriate fire protection measures for ro-ro space with different ventilation conditions. This report gives the reader the background of the project with the review of literature together with review of accident investigation reports, inventory of ventilation design and a documentation of the performed hazard identification workshop that was held with suppliers, authorities, crew and ship owners.

The final report of RO5 will present overall project result from tests, computer simulations including recommendations and concept solutions.

The accident investigation review shows that the most common way to operate the ventilation system in case of a fire onboard was to shut it down. From the workshop the comments from crew was the interest to learn more how to use the ventilation system onboard. Densely stowed cars, which made it hard for the fire fighters to approach the fire, was mentioned as a problem in 7/10 accident reports with closed ro-ro spaces and in 3/4 reports with open ro-ro spaces.

The intention with the SOLAS regulations is to structurally divide passenger ships so that a fire cannot spread, and that fire extinguishing system or horizontal divisions should exist to control a fire in the space of origin. While on the other hand the principle of large ro-ro spaces is an important part of the maritime industry. Some of the accident investigations reveal that the large spaces such as open ro-ro spaces make it difficult to meet the functional requirements of the regulations and that open ro-ro spaces may be prohibited. The same conclusion is made from the two zone fire simulations conducted in the project. The simulations show that both increased natural ventilation and increased mechanical ventilation results in larger fire development. The conducted parameter simulation study shows that if natural ventilation is nevertheless required, the openings should, in terms of fire development, preferably be constructed as wide as possible and with as low sill and soffit height as possible.