A portion of a line from a line laying vessel to a touchdown support point on or near to the seabed is imaged with a 3 dimensional sonar imaging system to produce coordinates of a series of touchdown points using a time sequence of sonar images, and the time series of touchdown points is recorded.

A portion of a line from a line laying vessel to a touchdown support point on or near to the seabed is imaged with a 3 dimensional sonar imaging system to produce coordinates of a series of touchdown points using a time sequence of sonar images, and the time series of touchdown points is recorded.

There is provided a method of interconnecting a conduit and a plurality of subsea structures. The method comprises providing a first manifold header in-line of the conduit, where the first manifold header has at least one valve installed therein. A portion of the conduit is lowered to the sea bed such that the first manifold header is engaged with a first subsea structure, and a further portion of the conduit is lowered to the sea bed. A second manifold header, having at least one valve installed therein, is provided in-line of the conduit and engaged with a second subsea structure. The length of conduit provided on the sea bed between the first subsea structure and the second subsea structure is significantly greater than the distance between the first and second subsea structures.

There is provided a method of interconnecting a conduit and a plurality of subsea structures. The method comprises providing a first manifold header in-line of the conduit, where the first manifold header has at least one valve installed therein. A portion of the conduit is lowered to the sea bed such that the first manifold header is engaged with a first subsea structure, and a further portion of the conduit is lowered to the sea bed. A second manifold header, having at least one valve installed therein, is provided in-line of the conduit and engaged with a second subsea structure. The length of conduit provided on the sea bed between the first subsea structure and the second subsea structure is significantly greater than the distance between the first and second subsea structures.

A method of joining a first pipe section to a second pipe section includes positioning the two pipe sections in an end-to-end configuration to define therebetween a joint to be welded, measuring the degree of alignment of the pipe sections when they are in the end-to-end configuration in a position ready for welding, ascertaining the relative movement required of the pipe sections in order to improve their alignment, effecting the relative movement so ascertained, and welding together the two pipe sections. The method may include the use of geometric data of the end of the pipes in order to ascertain the relative movement required of the pipe sections. A control unit may be used to calculate, using such data, a target orientation that lines up the pipe sections. The measuring step may be performed using, for example, a laser or a camera and backlight.

A method of joining a first pipe section to a second pipe section includes positioning the two pipe sections in an end-to-end configuration to define therebetween a joint to be welded, measuring the degree of alignment of the pipe sections when they are in the end-to-end configuration in a position ready for welding, ascertaining the relative movement required of the pipe sections in order to improve their alignment, effecting the relative movement so ascertained, and welding together the two pipe sections. The method may include the use of geometric data of the end of the pipes in order to ascertain the relative movement required of the pipe sections. A control unit may be used to calculate, using such data, a target orientation that lines up the pipe sections. The measuring step may be performed using, for example, a laser or a camera and backlight.

A method of aligning first and second pipes end-to-end in a position ready for welding. Each pipe has an end bevelled with a shape scanned and stored in memory of a control unit. At least one of the pipes has machine readable codes distributed around their circumference of the pipe. The method includes effecting relative movement of the ends of the first and second pipes towards each other, reading at least one of the codes with a reader, and ascertaining the relative movement required to align the pipes in accordance with a target orientation. The relative movement is ascertained with information provided by the read code and the shapes of the bevelled ends stored in the control unit memory. In other aspects, a closed loop control method and machine-learning may be used to align the pipes. A pipe-laying vessel including pipe handling equipment and the control unit is also provided.

A method of aligning first and second pipes end-to-end in a position ready for welding. Each pipe has an end bevelled with a shape scanned and stored in memory of a control unit. At least one of the pipes has machine readable codes distributed around their circumference of the pipe. The method includes effecting relative movement of the ends of the first and second pipes towards each other, reading at least one of the codes with a reader, and ascertaining the relative movement required to align the pipes in accordance with a target orientation. The relative movement is ascertained with information provided by the read code and the shapes of the bevelled ends stored in the control unit memory. In other aspects, a closed loop control method and machine-learning may be used to align the pipes. A pipe-laying vessel including pipe handling equipment and the control unit is also provided.

A system and method for moving an elongate element from a first position towards a second position against an upright structure on a vessel are disclosed. The system includes a holding element for holding the elongate element in the first position; a first sliding member pivotally connected to an end region of the holding element, and moveable along a base, ground or deck surface; a further sliding member pivotally connected to a further end region of the holding element, and moveable along the upright structure; and a hoist system operably engaged with the upright structure, the end region of the holding element and the further end region of the holding element, for drawing the holding element towards the upright structure such that the elongate element is moved towards the second position, wherein the hoist system comprises a first portion and a further portion, the first portion arranged to exert a force in a first direction and the further portion arranged to exert a force in a further direction.

A system and method for moving an elongate element from a first position towards a second position against an upright structure on a vessel are disclosed. The system includes a holding element for holding the elongate element in the first position; a first sliding member pivotally connected to an end region of the holding element, and moveable along a base, ground or deck surface; a further sliding member pivotally connected to a further end region of the holding element, and moveable along the upright structure; and a hoist system operably engaged with the upright structure, the end region of the holding element and the further end region of the holding element, for drawing the holding element towards the upright structure such that the elongate element is moved towards the second position, wherein the hoist system comprises a first portion and a further portion, the first portion arranged to exert a force in a first direction and the further portion arranged to exert a force in a further direction.