Abstract: A resting device (1) of at least one portion of a linear structure (2) is for crossing an uneven underwater topography. The resting device (1) is suitable for supporting at least one portion of the linear structure (2) that defines a longitudinal direction (X-X) coincident with or parallel to the longitudinal development direction of the linear structure (2). The resting device (1) includes at least one buoyant element (3) and at least one tether (4), suitable for constraining the resting device (1) to a bed (5). The at least one buoyant element (3) is suitable for providing a sufficient buoyancy to keep the at least one tether (4) under tension. A deck (6) has a shape and material that allows distributed resting of at least one portion of the linear structure (2) on the resting device (1).

Abstract: An electronic control system configured to control a variable-configuration lay ramp of a pipeline laying vessel, to lay a pipeline on the bed of a body of water, is configured to: acquire data including data related to the configuration of the lay ramp, data related to the laying vessel, and data related to the forces transmitted by the lay ramp and the laying vessel to the pipeline; generate a plurality of step sequences to change the configuration of the lay ramp from a first to a second work configuration; and select a best step sequence as a function of the plurality of step sequences and the acquired data, so as to minimize the stress induced in the pipeline at each intermediate configuration between the first and second work configuration.

Abstract: A stinger extends away from an end of a vessel, and a pipeline passes over the stinger as the pipeline is laid from the vessel. The inclination of the pipeline increases as the pipeline passes along the stinger and after leaving the stinger until the pipeline reaches an inflection point beyond the end of the stinger at which inclination is at a maximum. Inclination of the pipeline thereafter reduces until the pipeline touches down on the seabed. A method of S-laying the pipeline includes providing guides on the stinger that limit lateral movement of the pipeline relative to the stinger and moving the vessel and the stinger during S-laying to an orientation in which the longitudinal axis of the stinger is inclined to the path of the pipeline just laid. The vessel and the stinger are rotated about a vertical axis passing through or adjacent to the inflection point.

Abstract: An electronic control system configured to control a variable-configuration lay ramp of a pipeline laying vessel, to lay a pipeline on the bed of a body of water, is configured to: acquire data including data related to the configuration of the lay ramp, data related to the laying vessel, and data related to the forces transmitted by the lay ramp and the laying vessel to the pipeline; generate a plurality of step sequences to change the configuration of the lay ramp from a first to a second work configuration; and select a best step sequence as a function of the plurality of step sequences and the acquired data, so as to minimize the stress induced in the pipeline at each intermediate configuration between the first and second work configuration.

Abstract: A stinger extends away from an end of a vessel, and a pipeline passes over the stinger as the pipeline is laid from the vessel. The inclination of the pipeline increases as the pipeline passes along the stinger and after leaving the stinger until the pipeline reaches an inflection point beyond the end of the stinger at which inclination is at a maximum. Inclination of the pipeline thereafter reduces until the pipeline touches down on the seabed. A method of S-laying the pipeline includes providing guides on the stinger that limit lateral movement of the pipeline relative to the stinger and moving the vessel and the stinger during S-laying to an orientation in which the longitudinal axis of the stinger is inclined to the path of the pipeline just laid. The vessel and the stinger are rotated about a vertical axis passing through or adjacent to the inflection point.

Abstract: A guide device for supporting an underwater pipeline along a feed path as it is being laid. The device is fitted to a laying ramp and has a cradle housing the pipeline; a frame fixed to the laying ramp; and a spacer mechanism located between the frame and the cradle to selectively adjust the distance between the cradle and frame. The device further includes a shock absorber connected to the cradle. The invention includes a method for using the device.

Abstract: A guide device for supporting an underwater pipeline along a feed path as it is being laid. The device is fitted to a laying ramp and has a cradle housing the pipeline; a frame fixed to the laying ramp; and a spacer mechanism located between the frame and the cradle to selectively adjust the distance between the cradle and frame. The device further includes a shock absorber connected to the cradle. The invention includes a method for using the device.

Abstract: This invention provides a seismic joint for an underwater floating tunnel having: (a) a joint portion (i) having a transverse section essentially the same as that of the tunnel, (ii) being rigidly fastened to land at one end (A) thereof, and (iii) being elastically constrained to the tunnel at its other end (B) via a plurality of operably affixed means which performs an elastic function and a damping function; (b) a collar welded onto the external surface of the tunnel facing end (B) of the portion, said collar being capable of sliding on and along the external surface of the joint portion; and (c) a means for providing a water-tight seal between the internal surface of the collar and the external surface of the joint portion.

Abstract: The present invention relates to a thermally insulated pipe for the construction of underwater pipelines, characterized by being formed from prefabricated pipe portions welded together, each portion being constituted by two concentric tubes of different diameter which are connected together at their ends by means of special cylindrical pieces having a double T section which are welded to the two tubes in such a manner as to form between them an annular interspace which is filled with thermally insulating material.