System for use in building and deployment of an elongate element (202) in a J-lay operation. The system includes an upright structure (206); a winching element (204) retractable along an axis within the upright structure (206); a coupling element (210) connected to the winching element (204), for coupling the winching element (204) to an elongate element (202); and a catcher element (212) configured to retain the coupling element (210) in alignment with a predetermined axis within the upright structure (206) during retraction or extension of the winching element (204).

A laying tower for laying pipelines on the bed of a body of water has a supporting structure extending along a longitudinal axis and provided with guides parallel to the longitudinal axis; a first clamp, which is mounted on the supporting structure and configured for selectively clamping and releasing the pipeline in a given point along the longitudinal axis; and a second clamp, which is selectively movable along a path, which extends along a first section above the first clamp; and a second section below the first clamp and, partly, below the supporting structure and configured for selectively clamping and releasing the pipeline along the path.

A laying tower for laying pipelines on the bed of a body of water has a supporting structure extending along a longitudinal axis and provided with guides parallel to the longitudinal axis; a first clamp, which is mounted on the supporting structure and configured for selectively clamping and releasing the pipeline in a given point along the longitudinal axis; and a second clamp, which is selectively movable along a path, which extends along a first section above the first clamp; and a second section below the first clamp and, partly, below the supporting structure and configured for selectively clamping and releasing the pipeline along the path.

A tubular installation apparatus (1) including a lay tower (2) mounted to a support structure (4). The lay tower (2) is configured to lower a tubular section along a firing line (L) extending along the lay tower (2). A magazine (3) is removably mounted to the lay tower (2) and configured to be pre-loaded with a plurality of tubular sections. A feed mechanism (23, 25) is configured to feed one or more tubular sections from the magazine (3) to the firing line (L) of the lay tower (2) for connection to the end of a catenary.

A tubular installation apparatus (1) including a lay tower (2) mounted to a support structure (4). The lay tower (2) is configured to lower a tubular section along a firing line (L) extending along the lay tower (2). A magazine (3) is removably mounted to the lay tower (2) and configured to be pre-loaded with a plurality of tubular sections. A feed mechanism (23, 25) is configured to feed one or more tubular sections from the magazine (3) to the firing line (L) of the lay tower (2) for connection to the end of a catenary.

A hang-off insert for hanging-off a flexible elongate subsea element from a surface vessel has a circular loop that includes circumferentially-spaced support segments. Collectively, the segments define a substantially planar support face of the insert and have respective radially inner faces that define an inner radius of the loop. The radially inner faces of the support segments can be positioned at various radial positions to determine the inner radius of the loop and hence to adapt the circumference of the loop to suit different diameters of elongate subsea elements. With the hang-off insert supported by a hang-off structure of the vessel, a laterally-protruding hang-off feature of the elongate subsea element extending through the loop may be rested on the support face to transfer suspended weight loads to the hang-off structure.

The disclosure provides a pipe-laying vessel including a pipe-laying tower extending upwardly from the vessel, and the vessel includes at least three separate workstations spaced apart along the length of the tower. The disclosure also provides a pipe-laying vessel including a pipe-laying tower extending upwardly from the vessel, and the vessel includes at least two clamping assemblies for clamping a pipeline, the clamping assemblies being mounted along the length of the tower, and at least one workstation mounted on the tower. The workstation is mounted on the tower below a lowermost clamping assembly. The disclosure also provides a method of J-laying pipeline from a vessel, a method of abandoning a product from a vessel, and a method of recovering a previously abandoned product to a vessel.

The disclosure provides a pipe-laying vessel including a pipe-laying tower extending upwardly from the vessel, and the vessel includes at least three separate workstations spaced apart along the length of the tower. The disclosure also provides a pipe-laying vessel including a pipe-laying tower extending upwardly from the vessel, and the vessel includes at least two clamping assemblies for clamping a pipeline, the clamping assemblies being mounted along the length of the tower, and at least one workstation mounted on the tower. The workstation is mounted on the tower below a lowermost clamping assembly. The disclosure also provides a method of J-laying pipeline from a vessel, a method of abandoning a product from a vessel, and a method of recovering a previously abandoned product to a vessel.

A pipeline bundle for a riser tower or tie-back is manufactured offshore by suspending the bundle from an installation vessel, adding structural core sections successively to an upper end of the suspended bundle, lowering the bundle after adding each successive core section, and feeding one or more lengths of flowline pipe beside the core sections for incorporation into the bundle. The flowline pipe is coiled on a reel or carousel as a full-length piece before being uncoiled progressively as core sections are added to the lengthening bundle. The flowline pipe is then engaged with guide frames and/or buoyancy blocks supported by the core sections, by movement in a radially-inward direction through a radially-outer opening in a retainer formation. The opening is then closed to hold the flowline pipe in the retainer formation.

A subsea energy storage installation comprises a pumped-storage system having pumping and hydropower generation components for, selectively, converting electricity into potential energy by expelling water from within a tank into the surrounding sea and for generating electricity from an incoming flow of water re-entering the tank under hydrostatic pressure. The tank comprises at least one elongate rigid pipeline that may he lowered to the seabed as part of a to viable unit or laid on the seabed as a pipe string launched from a surface vessel.