Abstract: System of submarine linking between the anchoring cylinders of the legs of a platform and the relating foundation piles in which the anchoring cylinders are constituted each by two coaxial cylinders defining between each other a radially expansible annular interspace, the inner cylinder being made of steel with yield strength not higher than the half of the yield strength of the relating foundation pile, which is provided in its turn, in the zones wherein the linkage is to be accomplished, with an inner thickening and with a sequence of slots and toothings on its outer surface as well as, possibly, with inner peripheral ribs.

Abstract: A seal system for a spherical joint in which the metal seal ring is sandwiched coaxially between two wedge-shaped metal compression rings which are inserted into corresponding cavities in the front surfaces of the seal ring and are pressed against a metal stop ring by a series of flat springs which become preloaded as a result of forcing the female part of the joint onto the male part.

Abstract: Method for tightly jointing a sleeve to a submarine pipe laid on a very deep sea-bottom, characterized by the preliminary stages of providing a series of grooves on the inside surface of the sleeve, and of filling each one of said grooves with two half-rings made of a material collapsible under high pressures up to a 70% variation of its volume. A type of such a material is moreover described.