An ice-rated Canadian large surface combatant

What would a 15,000-to-22,000-ton ice-rated Canadian surface combatant with heavy guns be called?

Without missiles, a heavily armed icebreaker or very large patrol vessel; its twin 5-inch mount could be unusually practical in Arctic cold.

The proposed Canadian ship displaces 15,000 to 22,000 tons and carries twin 5-inch guns, 76 mm secondary weapons, and hangars large enough for two Chinooks. Without missiles, the answer classifies it as a heavily armed icebreaker or very large patrol vessel. Arctic service is presented as one circumstance in which a twin 5-inch mounting could make sense. Keeping the guns warm would otherwise require difficult and expensive heating arrangements. The larger mounting's internal space and heat from operating both guns are suggested as advantages in extreme cold.