Abstract: In mobile laying apparatus for laying an elongated element, such as a cable, in a trench, especially a trench in a sea bed, which apparatus is advanced in a predetermined direction and includes apparatus for digging the trench and ways along which the element slides as it is deposited in the trench, tension control apparatus and a method for preventing the accumulation of such element upstream of the laying apparatus as the element is laid. In the method, a tension force is applied to the element so that the tension thereon upstream of the laying apparatus is at least equal to the tension on the element downstream of the laying apparatus. The tension control apparatus includes motor driven rollers or tracks at the ways which engage the element. The torque which the driving motors apply or alternatively, the energization of the driving motors and the advance of the laying apparatus is controlled by the position of a portion of the element upstream of the laying apparatus.

Abstract: A mooring buoy structure for tanker ships is disclosed which comprises an anchoring block secured to the sea bottom, a vertical structure for supporting piping which conveys crude petroleum and like fluids from and to the ship, and a swinging arm installed above the anchoring block and fastened to a structure capable of being rotated about the buoy axis to orient the mooring arm, the latter also being capable of limited vertical rotation in a vertical plane.

Abstract: A control system for subsea oil wells, more particularly well heads, is disclosed, which comprises, in combination, an electronic command and control unit, a valve actuating hydraulic electric unit, a power generator unit, and interconnection devices for interconnecting the hydraulic lines for controlling the whole system from the surface with the hydraulic units for commanding the electric-hydraulic unit.

Abstract: A system is provided for buoyantly supporting an offshore structure so that it may be floated to a location in a body of water and then permitted to sink to the bottom, which consists of self-stabilizing apparatus comprised of a set of floodable chambers disposed around a central axis and a generally horizontal distributor, located above the floodable chambers to supply water thereto, whose axis is parallel to the axis of the floodable chambers. The distributor consists of an inner chamber which is connected to a water supply, an outer chamber which is partitioned into a set of compartments that complement the floodable chambers and an annular wall between the inner chamber and the compartments permitting an overflow of water from the inner chamber to the respective compartments, and each compartment is connected to its diagonally opposite floodable chamber so that water flows from it to that floodable chamber.