Icebreaker is a ship designed to travel through ice-covered waters. Icebreakers use their extraordinary power to push their bows up on top of the ice until the weight of the ship causes the ice to collapse. The ship must have a specially designed bow and a strengthened hull. The largest icebreakers are designed to break ice that is 8 feet (2.4 meters) thick while maintaining a slow but steady speed. By backing up and then ramming the ice, some icebreakers can break through ice that is more than 23 feet (7 meters) thick.
In the Arctic and Antarctic, polar icebreakers are used to rescue ships trapped in ice, to conduct scientific research, and to escort supply ships through ice-covered waters. Subarctic icebreakers are used in winter to break up the relatively thin ice that covers seas, lakes, and rivers outside polar regions. Countries that operate polar icebreakers include Argentina, Canada, Germany, Japan, Russia, Sweden, and the United States.
