Abstract: A multi-purpose marine structure intended to be submerged and installed on a sea bed. The structure comprises an outer peripheral body and a tapered inner section. The outer peripheral body is intended to be founded on a sea bed and comprises a tubular ring-formed body of concrete, the base of which is constructed and arranged to rest on a sea bed along its entire base periphery. The inner section is also of concrete and is formed as a cone or polyhedron having a lower end which is fixed to the outer peripheral body, the inner section tapering upwardly and inwardly from its lower end. The inner section and outer body together form a monolithic integral concrete unit, the inner section being fixed to the outer body along the inner periphery of the outer body.

Abstract: A rotary ice-breaking body having a spiral rotary blade is attached to a structure for use in icy waters at a part falling in contact with an ice lump or ice floe. The rotary blade is actuated to bite into the ice lump and to lift up or press down the ice lump. The ice lump is broken by the flexural stress and the structure is protected from influences of the ice lump. One rotary ice-breaking body may be disposed to constitute the outer periphery of the structure. Alternately, a plurality of rotary ice-breaking bodies may be disposed to surround the structure so that they are driven and rotated simultaneously or independently.

Abstract: A device (4) for thermally protecting the side of a tabular iceberg (1) produces a vertical layer of calm water (7) between itself and the vertical side wall of the tabular iceberg. This thermal protective device is suspended from a mechanical protective device, which may comprise a wall of floating towers (5). The protective device comprises panels (8) of woven or non-woven material parallel to the vertical side wall of the tabular iceberg, each of said panels having a width greater than its height, being suspended from a horizontal cable (10) passing through a top hem of the panel and being stretched taut by ballast (9).

Abstract: Method and apparatus for protecting subsea wellheads and christmas trees from damage by anchors, fishing nets, trawl boards, and other towed devices. The apparatus includes an annular, rigid protective enclosure with inner and outer walls that define a hollow annular chamber, and a plurality of bag-like containers spaced around and attached to the enclosure's outer wall. The annular chamber is in communication with the interiors of the containers by means of ports through the enclosure's outer wall, whereby when cement is pumped into the chamber it also flows into and fills the containers to form a smoothly contoured shield around the enclosure. Should an anchor or other device become fouled on this shield, the container or containers involved will break away and let the anchor continue on its way up and over the enclosure without damage to the wellhead or other well equipment.

Abstract: An offshore structure for use in arctic waters containing large moving ice masses such as icebergs wherein the structure has a wear surface arranged around the periphery of its support portion at least in the region of the support portion of potential contact with moving ice masses. A layer of resilient material is disposed between the wear surface and the support portion in order to reduce the forces imposed on the structure by the impinging ice masses.

Abstract: A vertical wall is placed next to the flank of an iceberg to retain a vertical layer of trapped water in contact with the iceberg. Zig-zag tubes are threaded through the wall at intervals so that the "elbows" in the zig-zags engage the iceberg flank to keep a fixed distance off.

Abstract: The panels are disposed in parallel to one another and are held in contact with the lower surface of a tabular iceberg by arms or cables attached to anchor points on the upper surface of the iceberg and by gas-filled chambers attached to the panels. The panels are stretched by ballast weights attached to their lower edges.

Abstract: A new and improved shock absorbing structure and method for use on a jack-up off-shore drilling rig is disclosed. The shock absorbing structure is designed for mounting on the bottom of each existing leg of the drilling rig and comprises a novel bottom member fixedly attached to each leg with the bottom member having a piston member positioned in the central portion thereof. The piston member is associated with at least one compression member formed around the piston member with the compression member being designed to absorb shock during a shock absorbing condition on the drilling rig leg. The compression member is fixedly attached to the bottom member by retaining means thereby making the structure self contained.Also disclosed is a new and novel method utilizing the shock absorbing structure on a jack-up off-shore drilling rig.

Abstract: A wall for protecting tabular icebergs against the mechanical effects of the waves and swell contains between the protective wall and the vertical side face of the tabular iceberg to be protected a layer of seawater subject to level variations of smaller amplitude than is the seawater outside said protective wall. The protective wall comprises vertical curtains parallel to the vertical side wall of the tabular iceberg to be protected. These curtains are attached to cables which maintain them in a partially submerged position, supported by gantries on the substantially horizontal upper surface of the tabular iceberg to be protected.

Abstract: A blowout prevention system for an offshore structure positioned on the underwater bottom in a body of water which contains moving ice masses that could force the structure off location wherein a surface blowout preventer stack for conventional well control is connected to the upper end of a riser with the lower end of the riser being disconnectably connected to a subsurface blowout preventer stack which provides the necessary well control should the structure be forced off location. The subsurface stack is positioned on a wellhead located in a chamber in the subsea bottom and is disconnectably connected to the riser so that the riser may be quickly removed from the subsea bottom should the structure be forced off location.

Abstract: An implantable sea-floor shoring cellar is provided for housing drilling equipment such as a blowout preventer stack at least partly below the sea floor in order to allow oil well drilling by drill ships in shallow water areas where the distance between the sea floor and the drill ship is not sufficient to allow for normal positioning of the blowout preventer stack above the sea floor. The implantable sea-floor shoring cellar includes a substantially cylindrical retainer wall assembly with an annular air ejector assembly including ejector nozzles mounted within the retainer wall assembly adjacent to a lower opening; and a plurality of discharge tubes are mounted over the ejector nozzles for removing earth loosened from the sea floor during cutting of an opening below the retainer wall assembly so that the retainer wall assembly may be lowered without interference into place at least partly below the sea floor.

Abstract: A marine drilling riser is provided with a plurality of buoyancy cans having fail safe dump valves operative to vent compressed gas from the buoyancy cans and thereby cause rapid loss of buoyancy.

Abstract: A device for protecting off-shore structures stretched between two floating towers of the "Froude pole" type against the effects of ocean swell, comprising at least four floating poles, two vertical arrays of horizontal cables, and a deflection panel assembly attached to one of the vertical arrays of horizontal cables. The floating poles comprise a rigid metal structure between two metal cylinders of the same diameter. The vertical arrays of horizontal cables form opposed catenary curves and are braced by further horizontal cables extending between them.

Abstract: A cage construction for protection of well equipment at a subsea wellhead and during descent to or ascent from a subsea well, said cage construction comprising an open frame cage body means defining a longitudinal axis, an intermediate cage portion of selected lateral and vertical dimension to encompass well equipment supported from a wellhead at the sea floor, and end cage portions extending upwardly and downwardly from said intermediate cage portion serving as guidance means, each cage end portion including coaxial receptor members, the receptor member at the lower end portion being adapted to receive and to be supported from a wellhead part, and the receptor member at the upper cage end portion being adapted to align, receive and pass therethrough the lower end of a pipe string into said cage body means.

Abstract: A breakwater which has a rear wall and several front walls to break up the incident waves, the front walls having holes therein to pass the waves, which holes diminish in size from the front wall which takes the initial impact of the wave towards the back wall. In various embodiments the breakwater may have a sloping back wall, convex-concave indentations on the back wall, partitions dividing up into compartments the chambers in front of the back wall, and a sloping second wall.

Abstract: A gravity platform for supporting installations above a body of water, comprising a base for resting on the bed of the body of water, a structure secured to the base and rising vertically therefrom, a bridge provided with float means, and means enabling the bridge to be displaced along the structure, the base consisting essentially of a slab provided with stiffeners, such as a circular wall and diaphragms, essential for its mechanical strength, the structure forming a hollow column, impervious or not, rising from the middle of the platform, and the float means consisting of an impervious shell formed around the hollow column at the lower part at least of the bridge and forming, possibly with said hollow column, if it is impervious, a float the buoyancy of which is sufficient to support the assembly of the platform and its installations.

Abstract: A permanent pier piling for use in docks and the like in a body of water whereby an antifreeze solution within the piling circulates to distribute latent ground heat from the lower portion of the piling to the upper portion of the piling to maintain a fluid interface between the piling and the ice during the winter season.

Abstract: Apparatus for constructing an island in a body of water including a plurality of caissons and means for connecting the caissons in an end-to-end configuration to form a ring. Once the caissons have been connected together to form a ring and ballasted to set the caissons upon the bottom of the body of water, sufficient fill material is placed inside the ring of caissons to construct an island in the body of water.

Abstract: The combination of a marine structure having a foot disposed in the bed of a body of water and first means for reducing and preventing scours of the bed at the foot of the marine structure with the foot in place, second means mounting the first means for general vertical sliding movement along the foot, the first means having opposite first and second end portions, the first end portion being more remotely spaced from the foot than the second end portion in a first in-place operative position of the first means, and the second means mount the second end portions of the first means for the latter sliding movement.

Abstract: Apparatus and method for mooring a tension leg platform at an offshore location wherein the tensioned cables of the platform legs are laterally supported by a plurality of rigid, fixed-dimensioned support members which interconnect the legs and are vertically spaced at predetermined positions along the cables to reduce the unsupported length thereof and to thereby increase the fundamental frequency of the cables to a value higher than the flutter frequencies likely to be encountered. Resonant fluttering of the cables due to vortex shedding is thereby prohibited and the useful life of the cables is extended. The support members can be variably buoyant and/or can be adapted to provide storage for fluids produced at the offshore location.