Abstract: An oscillatable marine installation comprises a concrete and steel lattice shaft supported by means of a demountable pivot joint on a base fixed to the-sea-bed and including an anti-torque device. The pivot joint is made up of three parts: a casing fixed to the shaft, a part-spherical housing fixed to the base, and a pivot member. The pivot member has an upper part cooperating with the casing, a flange which can be fixed to the casing, and a lower part-spherical part housing which supports a resilient assembly and a bush fixed on the housing. The anti-torque device comprises a universal joint, concentric with the pivot joint. Two opposite pivots of the crosspiece of the universal joint are supported by the lower part of the shaft and the other two pivots by the base. At least two opposite pivots have damping devices and the pivots supported by the base are mounted on supports the height of which can be adjusted.

Abstract: The device comprises two concentric swivels, a first or mooring swivel being arranged on the outside of the second or bearing swivel, the second swivel being fixed to the end of a cartridge held in a movable manner in a tube forming a projection at the lower end of the shaft and an extension of an axial passage in the shaft. The cartridge is formed by a cage fitted with openings in which keys are housed. A ring is lowered between the keys and immobilizes them against the wall of the tube which forms an extension of the axial passage in the shaft. The method consists of lowering or raising the cartridge carrying the bearing swivel by means of a set of rods.

Abstract: A flexible joint for connection of two pipes comprises a cup-shaped piece which can be connected to a first pipe, a tubular piece which can be connected to a second pipe, the tubular piece being coaxial with the cuplike piece and being arranged partially inside it, and two flexible spherical rings arranged between the cuplike piece and the tubular piece. The two flexible spherical rings are bolted together and arranged on opposite sides of the center of oscillation, the concave surfaces of the rings being directed towards the center of oscillation and being concentric with respect to this center.

Abstract: A platform resting at the bottom of a body of water, including a plurality of longitudinally disposed bays supported by piers each consisting of a small number of transversely aligned posts resting on a common base and each supporting a cross-beam, each bay comprising a framework of longitudinal beams which rest at either end on the cross-beams, and a method of constructing the platform comprising the steps of preparing each pier onshore, transporting it to the installation site and setting it down on the bottom, raising the base at several points and adjusting their heights above the bottom in order to position the base horizontally, securing the base in that position by pouring concrete beneath it, preparing each bay on the shore, transporting it to the installation site and setting it down on two adjacent piers.

Abstract: An assembly for positioning a crane mounted on a support and intended to overhang the platform of a platform structure having a base which rests on the bed of a body of water. The crane is located on the vertical axis of a column offset with respect to a central shaft which carries the platform. The assembly comprises a mobile shaft element contained in the upper part of the offset column and having a base with jacks or a block and tackle permitting its emergence as far as the upper level of the offset column. The lower face of the crane support carries a downwardly extending shaft element which has the same diameter as the mobile shaft element. The two shaft elements are substantially coaxial when the platform is carried on the central shaft so that they may be joined together and raised as a unit.

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: 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: 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: 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: A platform device comprising an underwater structure equipped wth a base resting upon the bed of a body of water, and a bridge carried by said structure above the surface of the body of water, characterized in that the underwater structure comprises, in the base or in proximity thereof, a plurality of chambers which can be kept dry and can be isolated from one another, said chambers being equipped wth access means and being suitable to receive devices or apparatus connected to a network of piping systems placed upon the bed of the sea.

Abstract: A device for protecting the base of a structure resting or constructed on the bed of a body of water against undermining, comprising a curtain which extends without interruption parallel to the base of the structure at a certain distance therefrom in the direction of the body of water, characterized in that said curtain is an imperforate wall extending from the ground upward to a height which is but a minor fraction of the depth of the body of water whereby the whole of the wall is deeply immersed in the water.

Abstract: The present invention relates to devices for laying submarine pipelines, in which the pipeline, associated with floats attached to it at intervals, the whole assembly being contrived in order to produce a certain buoyancy, is equipped with chains resting upon the bed of the body of water and performing the function of a guide rope. The weight of those parts of the chains extending between the bed of the body of water and the pipeline, maintains the latter submerged at a certain distance above the bed of the body of water and the pipeline can be towed, for example by means of a tug, without any risk of it being damaged by striking said bed.The improvement which forms the object of the invention consists in attaching the chains or their equivalent, for example cables, not merely to the pipeline itself, but also to the floats.

Abstract: In order to pass a duct across a wall between two spaces in which different pressures prevail, there is formed in said wall a passage which is temporarily closed off by means of a panel applied in position by the pressure, whereafter, at the time at which the duct is to be passed across the wall, the pressures in the two spaces are equalized making it possible to remove the temporary closure, the duct is introduced through the passage, a temporary seal between the passage and the exterior of the duct is formed, the pressure difference between the two spaces is restored, and a final seal between the passage and the exterior of the duct is created.

Abstract: In order to form galleries or other subterranean cavities in the bed of a sheet of water, for example for the construction of a subterranean reservoir for storing petroleum, or for exploiting submarine deposits, a floating structure, comprising at least one and preferably two hollow shafts, is ballasted so that it rests upon the seabed or underwater surface, a bore is excavated in extension of each hollow shaft, down to the desired depth, a casing tube is inserted there, extending to above the sheet of water, and one of said casings is used as an access means for the excavation of the galleries or cavities, whilst the other if used to remove the spoil.

Abstract: A structure designed to rest upon the bed of a body of water, in particular to support fixed installations such as an off-shore drilling platform, comprising a central cavity without a base and surrounded by a double vertical wall spaced apart by vertical partitions, preferably of cylindrical shape, forming a plurality of compartments provided with bases at their bottom ends and extending above the double wall.

Abstract: A platform structure for maritime installations, designed to rest under its own weight upon the seabed through the medium of a base acting as the foot of a tower surmounted by an emergent superstructure, comprising a strong, watertight tubular member incorporated into the structure in order to form a shaft or chimney extending from top to bottom of the structure in order to protect the components of the installation against corrosion and shock loading, and in order also to make it possible to carry out in the dry the various operations required by the process. The tubular member can be used without a base in order to give direct access to the seabed. Preferentially, the tubular member will communicate with one or more radial, watertight tunnels formed in the base.