Abstract: An icebreaker vessel formed of a pontoon-shaped forecastle, a wedge-shaped ship bottom with a center keel, at least one pair of additional marine propulsion and steering systems along the ship bottom on either side of the keel, trimming devices for lifting or lowering the forecastle by predetermined amounts, and driven wheel assemblies mounted along both sides of the forecastle. The pontoon-shaped forecastle portion is of a larger width than the remaining part of the ship's hull. The additional marine propulsion and steering systems may consist of Voith-Schneider propellers or of one or several pairs of jet propulsion units. Portions of the forecastle and the wheel assemblies may be heated by hot cooling water supplied from the vessel's engines.

Abstract: A method of and apparatus for the construction of a modular barge is provided wherein individual floatation modules are assembled and secured one to another by the positioning and linking of separable alignment pins therebetween and the threading of tensioning cables therethrough. Each alignment pin has a generally elliptoid shape and an axial cable receiving bore therethrough. Each flotation module is formed with a plurality of sockets complementally shaped for the alignment pins and linked in pairs by transversely extending passages therethrough and spaced along adjacent side walls of the modules to be in registry with one another. With the modules in a spaced array, assembly cables are threaded through certain ones of the module passages. First ends of the cables are anchored to perimeter modules and the opposite ends are tensioned to draw the modules and alignment pins together, wherein the configuration of the alignment pins then facilitates alignment and coupling.

Abstract: An ice breaker in the form of a self-propelled vessel carrying outboard thereof, a horizontally-swingable preferably extensible boom adjustable from above water level to below water level to extend beneath floating ice. On the boom are one or more upwardly facing jet nozzels supplied with sea water under high pressure to cut ice from beneath.

Abstract: A method and apparatus for reducing ice forces on a marine structure erected in a body of water which becomes frozen through natural weather conditions. The structure has a low-ice-adhesional wall forming its perimetrical surface in the zone where natural ice will freeze onto or impinge against the structure. Enclosed chambers are built within the structure and may be in heat-transmitting relationship with the outer wall. Heat is applied to the chambers to heat and maintain the outer wall at a temperature above the melting point of the natural ice occurring in the water around it. In a preferred embodiment, the marine structure is formed with a heated wall which slopes upwardly and inwardly in the area of ice contact to provide a ramp-like surface upon which a sheet of ice will be forced with reduced friction as it moves against the structure. Thus, an edge of the sheet of ice will be prevented from strongly adhering to the structure either initially or subsequently.

Abstract: An improved vessel for use in ice-covered waters has a motion inducing tank disposed in its hull at a location spaced from the even-keel center of buoyancy of the hull. Ports communicate from the lower extent of the hull to the exterior of the hull below the hull load waterline for flow of water into and out of the tank in response to pressure in the tank being different from ambient pressure outside the hull. The tank extends vertically in the hull from a lower end located below the hull load waterline to an upper end located above the waterline substantially as far as the location of the ports below the load waterline. Airflow devices are coupled to the upper extent of the tank and are operable alternately for generating superatmospheric and subatmospheric air pressure in the tank. The airflow devices include an air pressurizing device having a suction connection and a discharge connection.

Abstract: A procedure and a novel vessel are provided for breaking ice. The procedure comprises the cyclical steps of firstly pretensioning an ice-sheet by plowing under a portion of the ice-sheet with the bow of an icebreaking vessel; secondly superimposing on that pretensioned ice-sheet, a massive momentum force due to the reaction of an impulse force due to accelerating water rapidly downwardly from within a bow chamber; and finally refilling the bow chamber with water. Preferably the impulse force is created by the high pressure exhaust gases from a combustion chamber, e.g. an explosive combustion chamber being applied directly to the water.