Abstract: A device for positioning a pipeline intended to rest on the bottom of the sea or of a body of water. In order to present a resistance to the drifting of the pipeline by the action of cross-currents, the pipeline is provided with a plurality of support members suitably distributed along the pipeline and extending in a direction generally parallel to the vertical plane containing the longitudinal axis of the pipeline. The support members project below the pipeline towards the bottom and are deformable in the vertical plane by the reaction of the bottom on the support members, but are transversely rigid.

Abstract: In a method of welding together two submerged pipe ends, the pipe ends are spaced apart and introduced through orifices into a receptacle by which they can be isolated from the surrounding medium. The spaced pipe ends are connected by a connection sleeve and after isolation are welded to the connection sleeve.

Abstract: An installation for the release of floats supporting by individual cables a structure submerged in an aqueous medium, comprising attachment means fixed on the structure and co-operating with one end of said cable, the other end carrying the float, liberating means co-operating with said attachment means, and a control station for said liberating means, wherein the first of said liberating means is connected to a principal control line connected to the control station, the subsequent liberating means being connected together in such manner that they are automatically and successively actuated after said first liberating means has been actuated via the principal control line, the principal control line and the connections between successive liberating means consisting of fluid pressure lines or electric cables.

Abstract: The invention relates to an oscillating installation installed at a fixed site in a body of water, comprising a shaft which rests on a heavy base, which itself bears on a bed, and which supports a platform at its upper part, the shaft is connected to the base by a ball-joint consisting of two hemispherical caps. The shaft is loaded in such manner that the joint is always under compression. Examples of forms of joint comprising packings between the two caps are described. The invention also relates to a method of laying such an installation, the latter being conveyed by flotation to the site, and the correction of listing by the use of caissons disposed along the shaft.

Abstract: A method and apparatus for fabricating an offshore structure intended to be installed at sea comprising a support structure and a platform mounted on the structure. The platform is made up of one or more pieces that are floatable in water. The support structure is immersed to a depth sufficient for the portion thereof intended for the reception of the platform to be situated near the level of the latter. The platform is then fixed to the support structure which is then made lighter and brought to the place where it has to be installed.

Abstract: The invention consists of an apparatus for laying a pipeline, such as an oil duct or a gas duct, in a body of water, wherein the pipeline, or a section thereof, is enclosed within a ballast tube such that an intermediate space is formed between the pipeline or pipeline section and the ballast tube, said space being filled with a liquid less dense than water, such as a light hydrocarbon, while the pipeline is being laid, but may be filled, after the pipeline has been laid, with soft water or with a liquid heavier than water such as a grouting having a base of a hydraulic or hydrocarbon binder. The invention also comprises the provision of a plug at one end of an assembly of pipeline section and ballast tube whereby a free end of said assembly may be secured as by welding to a second assembly of pipeline section and ballast tube at a position remote from the liquid contained in the intermediate space in said first assembly.

Abstract: An off-shore gravity type platform for supporting a processing installation above the surface of a body of water and for housing processing components, comprising a pressure-resisting watertight central shaft extending from top to bottom of the platform structure, the lower end of the shaft being surrounded by a coffered base structure with a protective wall surmounted by pillars co-operating with the shaft for supporting a bridge, the shaft being so sized that the platform has a positive buoyancy, the top of the protecting wall being located below the level of the body of water, and the pillars being hollow and being filled with concrete after the platform is in place.

Abstract: An apparatus and method for towing a pipeline in a body of water to a place where the pipeline is to be laid on the bed of the body of water, the pipeline having a positive buoyancy and being provided with trail-ropes distributed therealong which drag on the bed while the pipeline is being towed and maintain it at a certain distance above the bed, wherein some at least of the trail-ropes are connected to the pipeline at points spaced apart therein in such manner that such trail-ropes are formed with arcuate portions extending between the points of attachment to the pipeline so that when said arcuate portions drag upon the bed they are retained substantially parallel to the longitudinal axis of the pipeline thereby to oppose drift by a transverse current, said trail-ropes also optimally comprising means for penetrating the bed so as to offer increased resistance to drift.

Abstract: Apparatus for the release of submerged floats, characterized in that the float is connected to the structure it is intended to support by at least one opening collar which can be kept closed by a locking mechanism capable of being remotely controlled.

Abstract: A float device for use in laying a submarine pipeline from a launching base, comprising one or more tubes containing a liquid less dense than water, such as a hydrocarbon, and fixed to the pipeline so as to form therealong a plurality of compartments isolated from each other and each communicating with the sea via an opening or a pipe opening towards the bottom. Means may be provided for opening in each compartment a passage opening towards the top and for recovering the less dense liquid, driven by the water, to the outlet of said passages, or even for releasing the tube or tubes from the pipeline.

Abstract: The ends of submerged pipes are connected using a receiver provided with two apertures through which the pipe ends extend, the receiver being adapted to form a watertight enclosure with an intervention unit and housing means for closing the ends of the pipes comprising two stoppers bearing seal means to be applied against the inner walls of the pipe ends and being maintained spaced apart by a first boom, the receiver including means for supporting a sleeve to be connected to the ends of the pipes and a replacement boom located in the sleeve, the connection being performed by introducing the ends of the pipes to be connected into the receiver through the apertures, at least one of the pipe ends being introduced by movement of the receiver relative thereto, closing the ends of the pipes with the stoppers, causing an intervention unit to descend on to the receiver, providing a watertight enclosure therewith, removing the water from the enclosure and placing it under atmospheric pressure, placing the receiver und

Abstract: For laying a pipeline on the bed of the sea, a plurality of pipeline sections are successively towed by a tug exerting a traction effort at a point spaced to the rear of the front end of a pipeline section being towed, while another tug exerts a holding effort at a point spaced in front of the rear end, the front and rear ends being maintained near to the surface by a system of floats and trail-ropes and the intermediate portion of the pipeline section being ballasted so as to be supported on the sea bed, whereafter the front end of the pipeline section is welded to the rear end of a preceding section, and so on.

Abstract: The ends of submerged pipes are connected using a receiver provided with two apertures through which the pipe ends extend, the receiver being adapted to form a watertight enclosure with an intervention unit and housing means for closing the ends of the pipes comprising two stoppers bearing seal means to be applied against the inner walls of the pipe ends and being maintained spaced apart by a first boom, the receiver including means for supporting a sleeve to be connected to the ends of the pipes and a replacement boom located in the sleeve, the connection being performed by introducing the ends of the pipes to be connected into the receiver through the apertures, at least one of the pipe ends being introduced by movement of the receiver relative thereto, closing the ends of the pipes with the stoppers, causing an intervention unit to descend on to the receiver, providing a watertight enclosure therewith, removing the water from the enclosure and placing it under atmospheric pressure, placing the receiver und

Abstract: In the assembling and laying of an undersea pipe in which the already submerged pipe portion is suspended from a surface support, the end of the submerged pipe portion being supported on a variable inclination laying ramp, and a new pipe section is moved into alignment with the end of the pipe portion and fixed thereto, the submerged pipe portion is so suspended from the surface support that the tension in the pipe portion is maintained substantially constant irrespective of vertical movements of the surface support caused by the action of waves on the surface support.

Abstract: To enable the release and consequent recovery of a support float which supports a load, e.g. a pipe, as it is lowered to the sea bed, a marker buoy is lowered with the float to be released when the load reaches the sea bed, the marker buoy having an inflated flexible envelope which is trapped in a housing fast with the float and having an opening through which the float can escape only when it has been compressed to a predetermined extent under the effects of a predetermined hydrostatic pressure. The marker buoy is connected to the float by a cable and the float is released from the load either by operations on that cable, or on a release cable connected to the float, on appearance of the marker buoy at the water surface.

Abstract: The invention relates to a method of laying submarine pipelines by submergence from the surface or from an adjacent level with one point of the pipeline being secured near to the surface so that the pipeline on being submerged comprises a section descending from this point towards the bed and connected by a curved section to the part of the pipeline already laid on the bed, in which weights are suspended from the pipeline at intervals thereon, at least at the time of its submergence, such that the assembly has a slightly negative buoyancy and the pipeline sinks slowly in the water until it is slowed down and stopped when the weights contact the bed, the weights thus acting as a guide rope.

Abstract: For laying a submarine pipeline, hauling of the same is exerted by means of a force distribution cable which extends over the full length of the submerged part of the pipeline and which is attached to it by hangers, preferably in conjunction with heavy chains acting as guide ropes and anchoring blocks. A further cable attached to the head of the pipeline transmits directly thereto a part of the haulage force.

Abstract: For laying a submarine pipeline, hauling of the same is exerted by means of a force distribution cable which extends over the full length of the submerged part of the pipeline and which is attached to it by hangers, preferably in conjunction with heavy chains acting as guide ropes and anchoring blocks.

Abstract: The invention consists of a method and apparatus for laying a pipeline, such as an oil duct or a gas duct, in a body of water, wherein the pipeline, or a section thereof, is enclosed within a ballast tube such that an intermediate space is formed between the pipeline or pipeline section and the ballast tube, said space being filled with a liquid less dense than water, such as a light hydrocarbon, while the pipeline is being laid, but may be filled, after the pipeline has been laid, with soft water or with a liquid heavier than water such as a grouting having a base of a hydraulic or hydrocarbon binder. The invention also comprises the provision of a plug at one end of an assembly of pipeline section and ballast tube whereby a free end of said assembly may be secured as by welding to a second assembly of pipeline section and ballast tube at a position remote from the liquid contained in the intermediate space in said first assembly.