Släcksystem för ubåtar - vattendimma

Sammanfattning: This report is written on the behalf of SAAB Kockums AB to investigate the feasibility of using water mist fire protection systems on board conventional submarines as an alternative to the traditional solution using Halon 1301. Halon 1301 has since the late eighties been phased out due to environmental concerns. The report studies existing rules and regulations regarding fire safety onboard ships, focusing on water mist and submarines, together with a study of previously conducted studies and experiments. The report also includes basic descriptions of conventional submarines and water mist systems. The study regarding rules and regulations show that civilian merchant shipping and military submarines are in large affected by the same rules, with a few exceptions. The advantage of following the subsequent civilian standards is that certified systems and solutions already exists, and the drawback is that the system may not be as adapted to submarines as may be desired. The study regarding previously conducted tests and experiments clearly shows that water mist is a superior fire suppression system regarding its ability to rapidly cool fire gases and limiting fires without the need for large quantities of water. Its drawbacks are largely connected to “the small-fire syndrome”, the difficulties of full extinguishment of small fires. Water mist, in contrast to fire suppression systems using gas, has difficulties in fully extinguish hidden fires. In summary water mist is a viable replacement to Halon 1301 onboard submarines, provided that it’s combined with other systems to mitigate its drawbacks.