Arktika-class icebreaker
The "Arktika" class is a Russian (former Soviet) class of nuclear-powered icebreakers. Formerly known as "Project 10520 nuclear-powered icebreaker", they were the largest and most powerful icebreakers until the 2016 launch of the ship named Arktika. Ships of the "Arktika" class are owned by the federal government, but were operated by the Murmansk Shipping Company (MSCO) until 2008, when they were transferred to the fully government-owned operator Atomflot. Of the ten civilian nuclear-powered vessels built by Russia (and the Soviet Union), six have been of this type. They are used for escorting merchant ships in the Arctic Ocean north of Siberia as well as for scientific and recreational expeditions to the Arctic.
Sisu (1938 icebreaker)
The Finnish Board of Navigation decommissioned "Sisu", now the oldest and smallest icebreaker in the state-owned fleet, in 1974. At the time, Finland had a fleet of nine diesel-electric icebreakers in service and two more under construction. The new icebreakers, which had nearly five times the displacement and more than five times the power of the old "Sisu", were designed to guarantee year-round traffic to all Finnish ports in the Bothnian Bay. The second of these icebreakers was named "Sisu" in 1975.