How thick is the ice? How thick is the ship's hull?
8. How thick is the hull on an ice breaker? How thick is the ice that the ship must break?
From Mr. Harger himself
For all the specs on the ship, please see the Canadian Coast Guard page on the Louis S. St-Laurent.
Rick Krishfield tells us: Icebreakers usually have 2 hulls, one inside the other with an air space in between. I know that one icebreaker that I was on had a double hull with each hull that was 12 inch thick steel. Icebreakers are usually constructed to break 3-4 m ice if possible. Russian nuclear icebreakers are so powerful, that they can break even thicker ice.
The St-Laurent is a class 100A icebreaker, also known as a "heavy ice breaker." Here is an excellent description of the hull requirements for an icebreaker.