Abstract: Marine pipelaying is carried out from the surface of floating ice by use of modules which straddle a slot in the ice and carry the pipeline, each module having a large central float which is forced downward into the water and which functions to reduce loading on the sides of the ice slot.

Abstract: A process and apparatus are provided for the simultaneous trenching and installation of submarine pipelines. The apparatus is based on a single unit which includes an excavating portion, an attached ditch sidewall retention shield, and a pipeline installation guide. The excavator creates a trench of a slightly larger cross section than required, the shield prevents the trench from closing due to the collapse of the sidewalls, and the pipe guide causes the pipeline to be deflected into that portion of the trench protected by the shield. The pipeline is fabricated on the surface of the sea or on floating ice, and is supported and guided to enter the forward portion of the shield by a stinger or other means, when required.

Abstract: A method and apparatus are provided for forming an ice slot in an ice sheet by cutting discrete blocks of ice in the ice sheet, then gripping the blocks of ice with a claw-like attachment extending from a hydraulic arm and pushing the ice blocks downwardly with the hydraulic arm until the blocks reach a level with the underside of the ice sheet and then rotating the blocks under the surrounding ice sheet, whereby loads on the ice sheet are reduced and the ice blocks contribute to the load capacity of the ice sheet due to the buoyant upward pressure of the ice blocks.

Abstract: During winter construction of offshore Arctic pipelines, it is frequently necessary to cut an ice slot in order to lay a pipeline on the sea bottom. Once such slots are cut, they rapidly freeze over, so that it is necessary to remove ice from the slot during the pipelaying time span. The present invention provides a method and apparatus for removing the newly formed ice from the ice slot. An inclined plane, sized to fit within the ice slot width to be maintained, penetrates below the surface of the water within the slot and to a depth at or below the underside of the newly formed ice on the water's surface. By moving the plane along the surface, the ice is raised, broken, and then conveyed upward and then to one side out of the ice slot as spoil.

Abstract: An eccentric hinge is provided for laying submarine pipelines which facilitates joining long segments of the pipeline by raising adjacent ends of the segments, attaching the hinge thereto, and lowering the segments and hinge to the sea-floor while remotely applying tension to one of the segments.

Abstract: An electromagnetic system is provided for accurately sensing and remotely controlling a tool-to-workpiece spatial relationship. A typical application of the system may include a saw being sensor controlled through the process of removing a reinforced concrete covering from and about an underwater pipe or other metallic object that must be protected.

Abstract: Method and apparatus for removing oil from the surface of a body of water with a skimmer; the apparatus including a skimmer with baffled entry ports arranged on a plane inclined to the direction of current flow or about the periphery of a drum so that oil enters through the baffles into a chamber which is beneath an inverted funnel or within the axle of the drum; the method involving providing a skimmer having submerged baffle entry ports inclined to the direction of current flow, allowing the oil to enter the skimmer, and returning the skimmer to a horizontal position for removal of the oil therefrom through an inverted funnel suspended over the confined oil.