A device for jointing elements of a pipeline for the transport of fluids includes a support structure on which a pipeline section to be jointed is intended to be mounted, two parallel fixed rails, four plates each comprising a first element capable of cooperating with a rail and a second element fixed on the support structure. The first and the second elements of each plate is linked by a first cylinder aligned along a first adjustment axis and a second cylinder aligned along a second adjustment axis, and a system for controlling the cylinders of the plates to achieve movements along the first and second adjustment axes and capable of cooperating with a system for guiding in translation the support structure along the longitudinal axis of the pipeline section to allow jointing of the pipeline section and the pipeline element.

A device for jointing elements of a pipeline for the transport of fluids includes a support structure on which a pipeline section to be jointed is intended to be mounted, two parallel fixed rails, four plates each comprising a first element capable of cooperating with a rail and a second element fixed on the support structure. The first and the second elements of each plate is linked by a first cylinder aligned along a first adjustment axis and a second cylinder aligned along a second adjustment axis, and a system for controlling the cylinders of the plates to achieve movements along the first and second adjustment axes and capable of cooperating with a system for guiding in translation the support structure along the longitudinal axis of the pipeline section to allow jointing of the pipeline section and the pipeline element.

A subsea pipeline (14) has a friction-reducing outer coating, treatment or finish (30) that extends along discrete regions mutually spaced along the length of the pipeline. During laying, curvature is imparted to the pipeline (14) along its length, for example by the residual curvature method or by snake-lay, to create expansion loops (26) of increased curvature relative to intermediate portions (28) of the pipeline (14) that join those loops (26). Each of the loops (26) is coincident with a respective one of the regions that bear the friction-reducing outer coating, treatment or finish (30). This facilitates lateral movement of the loops (26) relative to the seabed (16) to mitigate and control buckling in use of the pipeline (14).

A method of installing a steel catenary riser comprises progressively unspooling and launching the riser into water from a reel-lay vessel. The riser is plastically deformed in a straightening process aboard the vessel, downstream of unspooling and upstream of launching the riser. The straightening process is adjusted to form at least one residual curvature loop of locally increased curvature in a length of the riser that will be suspended in the water above a touch-down point in use. Ballast weights are then attached to the at least one loop. Buoyancy elements may be attached to the riser above the at least one loop.