Abstract: An underwater gas/liquid reservoir 1, particularly designed to be used as a ballast/buoyancy tank in an offshore drilling platform, has a pressurized supply duct 2 for introducing gas into the reservoir to control the liquid level therein. The gas supply duct has two openings 8, 11, one near the bottom of the reservoir and the other near the top. A movable straddle packer 14 is disposed in the gas supply duct for selectively closing the bottom opening 8 so that gas is allowed to flow only through the top opening 11 of the supply duct. The packer can also be positioned to uncover the bottom opening 8 of the gas supply duct. In operation, the liquid level within the reservoir is controlled by the introduction or release of pressurized gas into or from the reservoir through the openings of the gas supply duct either to force liquid from the reservoir or to allow liquid to flow into it.

Abstract: A marine structure for guiding a plurality of ducts from deeper to higher submerged devices such as an oil well at the sea bottom and a production or storage station, respectively. The apparatus provided in accordance with the present invention compensates for relative movement between the higher and lower device by providing a rigid column having pivots at both the higher and lower devices. A plurality of ducts are attached to the rigid column and are connected to a corresponding plurality of higher ducts by similar pivot means. The higher ducts are arranged at the higher device so as to allow for relative longitudinal movement of the higher ducts with respect to the higher device.

Abstract: A personnel bridge for connecting a stationary offshore working platform 1 to a floating housing platform 2. A first span 3 is vertically pivoted at 5 to the platform 1 on one end, and vertically pivoted at 6 to the outer end of a second span 4 whose inner end is mounted to the platform 2 by a ball joint 8. The outer ends of the spans 3, 4 are also connected through a horizontal pivot axis 7, whereby movements between the platforms 1, 2 in three mutually orthogonal directions may be accommodated. The spans may be supported from a tower 10 by a fixed cable 9 pivotable at one end about an axis 11 aligned with the vertical axis 5, and by a winch controlled cable 12.