Every winter, the Gulf of Bothnia, northern arm of the Baltic Sea, completely freezes. Full of rocks, narrow and shallow, the Baltic Sea communicates with the outside by small straits. Therefore its water, not often renewed, is slightly salty (it is sweet even in the Gulf of Bothnia) and freezes when the cold winter settles over northern Europe.
Despite these restrictive conditions of navigation maritime traffic is dense. Over 80% of Finland's foreign trade transits by sea. When the sea is solidified and the boats no longer pass, icebreakers come in. They assist for free or nearly, commercial vessels wishing to go to ports isolated by ice. Without them, the Finnish economy would freeze at the same time as the sea.
In 1890, Finland launched to water his first icebreaker. At that time, the mission was limited to open the passage to the main ports of Hanko and Helsinki in the south. The steam icebreaker was slowly breaking the ice by successive assaults. Today, Finland has nine icebreakers. This fleet of destroyers allows 23 of the 60 Finnish ports established along the 1500 km of coastline, to keep open all year long, and to some 14 000 ships to reach their destination during the winter season.
Among them, Otso, powerful last generation icebreaker, built in 1987, advancing at an average speed of 16 knots in an ice 50 cm thick, sometimes more. The ice breaks up in front of his strong bow while his followers slip through behind him. When he is not solicited, it stops on the ice and waits. The idleness is usually short term. A commercial ship approaching the district in which operates the icebreaker does not take long to contact him to ask for his assistance. When conditions permiting, ice-breakers simply maintain open the main navigation channels. Commercial vessels can then take them on their own. But when the ice becomes thicker, the boats are assisted one by one. On the white immensity, the two vessels, in solidarity, only a trace a single wake.
Texte : Anne Jankeliowitch