Design and Strength of Vessels

Many different vessels may have additional strengthening and hull features that make them suitable for operations in polar waters. These "ice-class" features allow for greater survivability and flexibility in navigating frozen waters and will be reflected in the vessel's certification from the Classification Society she is registered with.

The main feature of ice-strengthened vessels is far more structural support from thicker plating, girder and bulkheads that result in a far sturdier construction. This is added to by more watertight division and protections for the propeller and rudder to ensure the vital components of the ship are protected from ice damage. 

Ice Flow and Strengthening

Due to how ice interacts with the pressure fields of ships created as they pass through the water, certain areas require greater strengthening than others. As a rule, greater strengthening is found:

General Features of Ice Class Vessels

Despite the numerous ice classification levels, certain features remain constant across them. These include: 

• A double hull construction allows air or additional water ballast to act as a buffer against external damage and internal flooding.
• A flattened hull and rounded bow ensure the vessel rises above the ice and breaks it by the ship's weight.
• Specialist paint that reduces friction to allow ice to slide past.
• Engine cooling arrangements include inlets and outlets that are designed to remain ice-free.
• No hull protrusions, such as fin stabilisers, would become damaged from striking ice.
• Protected propellers and rudders to minimise damage from contact with floating ice.
• A reinforced "ice belt" 1 meter on either side of the waterline consisting of thickened steel and additional bracing to protect that area from the worst of the pack ice impacts.