Abstract: The invention relates to a water navigable vessel having an ice-breaking bow and a rotatable screw mounted on the front on the bow for the purpose of advancing the vessel up onto an ice layer and failing the ice layer in flexural bending. The rotatable screw includes ice-cutting blades which form grooves within the top of said ice layer thus translating the rotational energy of said screw into a generally horizontal, (longitudinal) tractional force which pulls or drags the bow of said vessel forward and over said ice layer and, thereby, utilizes the mass of said bow to impart a downward gravitational force upon said layer of ice to cause it to fail flexurally.