ice conditions in the past, such as that of Runner 4 in 2006. The recovery tanks, equipped with heating and an inert gas system that uses nitrogen to displace explosive gases, have a total capacity of 1,200 cubic metres for spilled oil and 200 cubic metres for chemicals. In addition to recovery equipment the vessel carries of heavy duty oil boom. When the light components in crude oil evaporate over time, they form an explosive compound with air. For this reason special attention has been paid to prevent sparks and high surface temperatures in the ship and its equipment. In case of chemical spills, the ship can be overpressurized to prevent potentially toxic chemical substances from entering the ship and harming its crew. In such situation, the outer decks can be accessed via air locks. References Icebreakers of Finland Ships of the Finnish Navy Ships built in Finland 2009 ships