An installation of bottom-to-surface connections for at least two undersea pipes (11-1, 11-2) resting on the sea bottom (10), the installation comprising at least two hybrid towers, each comprising:
- a) a rigid pipe (1-1, 1-2) constituting a vertical riser having its bottom end (1a) fastened to a base (9-1, 9-2) resting on or anchored to the sea bottom (10), each rigid pipe being connected to a respective undersea pipe (11-1, 11-2) resting on the sea bottom, and having the top end (1b) of the riser tensioned in substantially vertical manner by a float (4-1, 4-2) immersed in the subsurface, the top end being connected to the float;
- and
- b) a flexible connection pipe (2-1, 2-2) providing the connection between a floating support (12) and the top end (1b) of said vertical riser via a junction device (3-1, 3-2) arranged at the top end (1b) of said vertical riser;
- wherein said two hybrid towers are connected together by at least one rigid separator bar (5) having a length larger than the diameter of the larger-diameter float, the longitudinal ends (5a) of each said separator bar (5) being fastened to the top ends (1b) of said risers or to said two floats by fastener devices comprising a rotary fastener and a hinge device (6), said fastener devices allowing at least two degrees of freedom for movement in rotation of said bar relative to an axis (YY′) perpendicular to the longitudinal axis (XX′) of said separator bar and perpendicular to the axis (ZZ′) of said float or of said top end of the riser to which it is fastened, wherein said rotation allows said separator bar (5) to perform (a) a first movement in rotation, and (b) a second movement in rotation relative to the longitudinal axis (ZZ′) of said float or of said riser end to which it is fastened, and
- wherein said rotary fastener and hinge device (6) comprise:
- a clevis (6c) rigidly fastened to one end of said separator bar, which clevis supports a transverse cylindrical rod (6d) forming the axis (YY′) for said first movement in rotation arranged perpendicularly to the longitudinal axis (XX′) of said separator bar and perpendicularly to the axis (ZZ′) of said float or of said riser top end to which said separator bar is fastened;
- a longitudinal element in the form of a finger (6a) having its top end with said transverse cylindrical rod (6d) passing therethrough forming the axis for said first movement in rotation and about which said finger (6a) is mounted so as to be free to move in rotation;
- and
- a sleeve forming a sheath (6b) having a cylindrical orifice adapted to receive said finger and allowing said finger to move in rotation about its longitudinal axis coinciding with the longitudinal axis of said cylindrical orifice in the sleeve arranged parallel to the axis (ZZ′) of said float or of said riser top end to which said sleeve is fastened, said sleeve including removable retaining means (6b2) suitable for retaining said finger in said cylindrical orifice of said sleeve.