Abstract:
A guide device (35), for supporting an underwater pipeline (2) along a feed path (Pl) as it is being laid, is fitted to a laying ramp (6), and has a cradle (36) housing the pipeline (2); a frame (37) fixed to the laying ramp (6); and a spacer mechanism (38) located between the frame (37) and the cradle (36) to selectively adjust the distance between the cradle (36) and the frame (37), and having a shock absorber (66) connected to the cradle (36).
Abstract:
A method of S-laying a pipeline from a vessel (103) is disclosed. A stinger (104) extends away from an end of the vessel (103) and the pipeline passes over the stinger (104) as it is laid from the vessel (103). The inclination of the pipeline to the horizontal increases as it passes along the stinger (104) and after it leaves the stinger (104) until it reaches an inflection point beyond the end of the stinger (104) at which the inclination of the pipeline to the horizontal is at a maximum. The inclination of the pipeline thereafter reduces until it touches down on the seabed. The method includes providing guides on the stinger (104) that limit lateral movement of the pipeline relative to the stinger (104) and moving the vessel (103) and the stinger (104) during S-laying to an orientation in which the longitudinal axis of the stinger (104) is inclined to the path of the pipeline (101) just laid on the seabed. The step of moving the vessel (103) and the stinger (104) comprises rotating the vessel (103) and the stinger (104) about a vertical axis passing through or adjacent to the inflection point.
Abstract:
Resting device (1) of at least one portion of a linear structure (2) for crossing an uneven underwater topography, wherein said resting device (1) is suitable for supporting at least one portion of said linear structure (2) that defines a longitudinal direction (X - X) coincident with or parallel to the longitudinal development direction of said linear structure (2); said resting device (1) comprising at least one buoyant element (3) and at least one tether (4), suitable for constraining said resting device (1) to a bed (5), wherein said at least one buoyant element (3) is suitable for providing a sufficient buoyancy to keep said at least one tether (4) under tension, and wherein said resting device (1) also comprises a deck (6) having a shape and material that allows distributed resting of at least one portion of said linear structure (2) on said resting device (1).
Abstract:
An electronic control system for controlling 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 (5), data related to the laying vessel (1), and data related to the forces transmitted by the lay ramp (5) and the laying vessel to the pipeline (2); generate a plurality of step sequences to change the configuration of the lay ramp (5) 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 (2) at each intermediate configuration between the first and second work configuration.
Abstract:
An electronic control system for controlling 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 (5), data related to the laying vessel (1), and data related to the forces transmitted by the lay ramp (5) and the laying vessel to the pipeline (2); generate a plurality of step sequences to change the configuration of the lay ramp (5) 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 (2) at each intermediate configuration between the first and second work configuration.
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:
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.