Abstract: The platform comprises an annular truncated cone of concrete which constitutes the main resistant element of the platform and is designed to take the thrust of ice, and a cylindrical steel part housed inside the annular truncated cone. Watertight passages parallel to the generatrices of the cylindrical wall are provided to house piles in the peripheral ring, close to the wall. A watertight passage well is provided in the cylindrical steel part for the passage of the drill pipes. A circular running track is provided for gantry cranes used for piles handling. The platform has two drilling rigs placed on one half of the platform and able to work simultaneously.

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: An oscillating structure for exploration at sea features a column which rests on a heavy base resting on the sea bottom, and which supports a platform above sea level. The column is connected to the base by an articulated joint which allows it to oscillate in all directions under action of swell, the articulated joint comprising two base plates cooperating with the substantially flat and parallel surfaces of the bottom of the column and the upper surface of the base respectively, two supports fixed on each of the plates and parallel one to the other, bearings, formed of two half bearings which can be dismantled, fixed to the ends of the said supports, the bearings of the supports fixed to the same base plate being in alignment, and a cross shaped member, whose branches are located in different planes, extending between the bearings.

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.