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.

Abstract: Suspended droplets of oil are separated from a waste water stream by the method and apparatus of the present invention. The oil and water mixture is injected into a partially submerged, vertical pipe. Gas bubbles injected into the lower end of the pipe, rise through the pipe and countercurrently contact the suspended oil droplets, thereby promoting the separation of the droplets from the waste water. The oil droplets coalesce and form a separate oil layer on top of the waste water which is readily withdrawn while clarified waste water is discharged from the lower end of the pipe. If employed to separate oil from a waste water stream on an offshore rig, the vertical pipe is submerged adjacent to the rig.

Abstract: A method and apparatus is disclosed for forming and maintaining an offshore ice structure in an Arctic environment. The structure is formed by a series of caissons oriented in a ring forming an enclosure capable of retaining a predetermined amount of water and thereby defining an ice island when frozen. The structure includes a passive heat extracting system which removes heat from the water within the enclosure and from the soil immediately below the enclosure and the caissons thereby advancing the freezing of the soil beneath the enclosure and water within the enclosure. In this manner, the lateral stability of the structure is improved by providing a single frozen mass of water and soil bonded in unitary construction increasing the foundational base of the structure. In addition, refrigeration means are provided to prevent surface melting of the ice within the enclosure and preserve the integrity of the ice structure during warmer months.

Abstract: A pressure sensing apparatus for measuring ice pressure forces while embedded in an ice pack is disclosed. The pressure sensing apparatus is thin in comparison to its width and length, having a stiffness similar to the average anticipated stiffness of the embedding material. The apparatus includes a housing having a first and second substantially flat plate connected at their outer edges and sensitive to external ice pressure forces. A thin member is supported within the housing between the first and second plate by a plurality of standoffs or ribs which subjected the member to reverse curvature bending upon the application of external pressures to the first and second plates. Wire resistance strain gauges are attached to the thin member to measure the strain of the member when subjected to the bending. In this manner, the pressure against the sensor can be correlated with the strain measurements resulting on the member.

Abstract: Suspended droplets of oil are separated from a waste water stream by the method and apparatus of the present invention. The oil and water mixture is injected into a partially submerged, vertical pipe. Gas bubbles injected into the lower end of the pipe, rise through the pipe and counter-currently contact the suspended oil droplets, thereby promoting the separation of the droplets from the waste water. The oil droplets coalesce and form a separate oil layer on top of the waste water which is readily withdrawn while clarified waste water is discharged from the lower end of the pipe. If employed to separate oil from a waste water stream on an offshore rig, the vertical pipe is submerged adjacent to the rig.