HOW DOES AN ICEBREAKER WORK?
An icebreaker’s bow is shaped so it slides on the ice in front of the ship and makes the ice break under its weight. The ship pushes the pieces of ice to one side. On one hand this creates a clear passage behind the ship, and it also serves to protect the vessel’s rudder and propeller. The strongest icebreakers achieve 70,000 horsepower— about as much as a medium-size aircraft carrier, which means they can break through 15-foot-thick ice. Other types of vessels employ hot steam to melt the ice, or they force compressed air under the ice floe, thereby making it rise. Also, rapidly pumping the ballast water back and forth through the ship generates a pitching movement that brings more power to bear on the ice. Each of these modern North Pole conquerors can cost up to $1 billion.