An offshore S-lay pipelaying vessel for laying a pipeline on the seabed, the vessel includes a hull and an elongated stinger having a hull end and a free end, the stinger being adapted to support the pipeline to be laid from the vessel. The stinger includes a stinger frame, possibly composed of one or more rigid stinger frame sections, possibly articulated sections. And, distributed over the length of the stinger, multiple pipeline support assemblies are mounted to the stinger frame that provide support for the pipeline.

A method of laying a pipeline in the bed of a body of water advancing a digging assembly along a pipeline laid along a path on the bed of the body of water, and digging a trench along the path in the bed of the body of water by means of the digging assembly, so a portion of pipeline settles onto the bottom of the trench. The method also includes acquiring, by means of the digging assembly, data related to the bathymetric profile of the portion of pipeline laid on the bottom of the trench, and comparing the acquired data with a set of permissible values. Further, the method includes emitting an error signal when the acquired data does not fall within the set of permissible values.

A method of laying a pipeline in the bed of a body of water advancing a digging assembly along a pipeline laid along a path on the bed of the body of water, and digging a trench along the path in the bed of the body of water by means of the digging assembly, so a portion of pipeline settles onto the bottom of the trench. The method also includes acquiring, by means of the digging assembly, data related to the bathymetric profile of the portion of pipeline laid on the bottom of the trench, and comparing the acquired data with a set of permissible values. Further, the method includes emitting an error signal when the acquired data does not fall within the set of permissible values.

A marine pipeline installation system and marine pipeline installation method are disclosed. The marine pipeline installation system includes a pipeline launch tower for launching the pipeline in a firing line along the pipeline launch tower into the sea, and one or more tensioners supported by the pipeline launch tower. The system further includes a pipeline guide supported in a pipeline launch trajectory between a pipeline storage and the firing line above the one or more tensioners, wherein the pipeline guide is provided opposite the firing line relative to the pipeline launch tower. A guide support structure is provided, which is embodied as a single-sided guide support arm arranged on one side of the pipeline guide only.

A marine pipeline installation system and marine pipeline installation method are disclosed. The marine pipeline installation system includes a pipeline launch tower for launching the pipeline in a firing line along the pipeline launch tower into the sea, and one or more tensioners supported by the pipeline launch tower. The system further includes a pipeline guide supported in a pipeline launch trajectory between a pipeline storage and the firing line above the one or more tensioners, wherein the pipeline guide is provided opposite the firing line relative to the pipeline launch tower. A guide support structure is provided, which is embodied as a single-sided guide support arm arranged on one side of the pipeline guide only.

A self-propelled vehicle used to lay pipe sections within trenches located on sloped terrain, and a method for using it, including: an undercarriage carrying a vehicle chassis and capable of climbing sloped terrain; a rotating platform which can be maintained level relative to the sloped terrain; and a boom with an angled boom head, capable of using two independent winch cables to lift and position individual pipe sections having differing lengths and diameters. The vehicle may be used to sequentially lift two or more pipe sections, one at a time, and to swing and position the pipe sections in a trench, end-to-end.

A self-propelled vehicle used to lay pipe sections within trenches located on sloped terrain, and a method for using it, including: an undercarriage carrying a vehicle chassis and capable of climbing sloped terrain; a rotating platform which can be maintained level relative to the sloped terrain; and a boom with an angled boom head, capable of using two independent winch cables to lift and position individual pipe sections having differing lengths and diameters. The vehicle may be used to sequentially lift two or more pipe sections, one at a time, and to swing and position the pipe sections in a trench, end-to-end.

An improved system and method for laying on the seabed a pipeline and/or installing a subsea riser including one or more accessories are disclosed. In the system, a trolley rail for an auxiliary trolley is provided which includes a retractable trolley rail part supported by the tower via an associated mobile rail support assembly. Displacement of the retractable trolley rail part together with the auxiliary trolley when arranged on said retractable trolley rail part with respect to the tower is allowed, between an active position, wherein the auxiliary trolley is positioned to engage on an accessory in the firing line, and a retracted and non-operable position wherein a clear envelope about the firing line is created.

An improved system and method for laying on the seabed a pipeline and/or installing a subsea riser including one or more accessories are disclosed. In the system, a trolley rail for an auxiliary trolley is provided which includes a retractable trolley rail part supported by the tower via an associated mobile rail support assembly. Displacement of the retractable trolley rail part together with the auxiliary trolley when arranged on said retractable trolley rail part with respect to the tower is allowed, between an active position, wherein the auxiliary trolley is positioned to engage on an accessory in the firing line, and a retracted and non-operable position wherein a clear envelope about the firing line is created.

Methods of laying subsea pipeline (1300) on a seafloor comprising: providing a pipe laying vessel (1100), placing a spooling structure assembly (1200) on the seafloor, and laying the subsea pipeline (1300) in a loop around the spooling structure assembly and associated systems.