Skidding system for an offshore installation or vessel

Abstract

The invention relates to a skidding system for an offshore installation or vessel, such as an offshore wind turbine installation ship, comprising at least one set of rails, and one or more carriages for supporting loads and moving the loads along the rails, e.g. from a storage position to an operating position and/or vice versa. At least one of the carriages is adaptable to different loads.

Claims

1. A skidding system for an offshore installation or vessel, comprising at least one set of rails, and one or more carriages, each carriage configured to support a load and move the load along the rails, wherein: at least one of the carriages is configurable to different loads, the at least one carriage comprises a plurality of supports supporting the load, and at least two of the supports are movable relative to each other.

2. The skidding system according to claim 1, wherein at least two of the supports are interconnected, directly or indirectly, via at least one telescopic beam.

3. The skidding system according to claim 1, wherein the carriage comprises a frame and at least one of the supports is releasably attached to the frame.

4. The skidding system according to claim 3, wherein at least one of the supports is bolted to the frame.

5. The skidding system according to claim 1, wherein the supports are arranged in a triangle or square.

6. The skidding system according to claim 1, wherein the at least one carriage comprises one or more fasteners configured to secure an associated load to the at least one carriage.

7. The skidding system according to claim 6, the one or more fasteners being mounted on or integrated in a support or supports.

8. The skidding system according to claim 1, wherein the at least one carriage comprises one or more fasteners configured to secure the at least one carriage or an associated load to the rails or to a deck of an offshore installation or vessel.

9. The skidding system according to claim 1, wherein the skidding system is fixed to a deck of an offshore installation or vessel.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) Aspects of the invention will now be explained in more detail with reference to the drawings, which schematically show embodiments of the skidding system.

(2) FIG. 1 is a perspective view of an offshore wind turbine installation ship (OWTIS) comprising a deck skidding system.

(3) FIG. 2 is a perspective view of a deck skidding system according to the present invention comprising differently configured carriages.

(4) FIG. 3 is a top view of another deck skidding system.

(5) FIG. 4 is a perspective view of a fastener for securing a load to a carriage.

(6) FIG. 5 is a perspective view of a fastener for securing a carriage to the deck of a ship.

DETAILED DESCRIPTION OF THE ILLUSTRATIVE EMBODIMENT

(7) FIG. 1 shows an offshore wind turbine installation ship (OWTIS) 1 provided with a deck skidding system 2 and a crane 3 for on and off loading loads, such as subsea modules or heavy weight structures 4. The skidding system comprises two sets of rails 5 extending in the longitudinal direction of the ship, a first set 5A extending alongside the crane 3 and a second set 5B juxtaposed to the first set and extending up to the crane. A plurality of skidding carriages 6, also known as e.g. pallets or carts, are supported on the rails 5 and in turn support loads, e.g. jacket foundations 4 for wind turbines.

(8) As shown in FIGS. 2 and 3, the carriages 6 comprise a pair of structural (skid) beams 7, e.g. having a rectangular hollow cross-section and extending in a direction transverse to the rails 5 and supported by skid shoes 8 (see also FIG. 5) resting on the rails 5. The skid beams 7 are interconnected via telescopic beams 9, e.g. extending parallel to the rails, and a truss 10 reinforcing the connection between one of the skid beams and the cylinder ends of the telescopic beams. The skid beams, telescopic beams and trusses together form a frame. Further, the carriages are provided, in a manner known in itself, with hydraulic push-pull units 11 to skid the carriages 6 along the rails 5.

(9) The ends of the skid beams 7 provide discrete positions locations for supports 12, which are bolted to the positions. In this example, the system comprises three types of supports: supports (ears) 12A releasably attached to an end of a skid beam 7, supports 12B releasably attached to a middle portion a skid beam 7, and supports 12C comprising an additional beam 13 connected ends of two skid beams 7. All three types provide support for one leg of a load, such as a jacket foundation. Other examples of supports include supports for two or more legs of a load and supports positioned in or near the middle of the carriage 6.

(10) The examples above provide an adjustable frame, which can be varied in length and/or width, with a plurality of positions for attachment of supports. Thus, the carriages can be adapted to a large number of different footprints and orientations, e.g. triangular footprints with the triangles in different (rotational) orientations to facilitate efficient use of deck area. This is illustrated in FIG. 2, which shows two juxtaposed carriages with identical triangular footprint but opposite orientations, i.e. rotated relative to each other over 180. FIG. 3 shows a carriage having a square footprint and two carriages having a triangular footprint but rotated relative to each other over 90.

(11) As shown in FIG. 4, each of the supports comprises a fastener, e.g. a gripper 14, for securing the load 4 to the carriage 6. In this example, each of the fasteners comprises a pin 15 extending through a leg of a jacket providing a positive lock between the leg and the fastener.

(12) Further, as shown in FIG. 5, the carriages 6 comprise fasteners for securing the carriage to the deck 1A of the ship. In this example, the fasteners secure the carriage in all three degrees of freedom: a first set of eyes 16 on the deck 1A and on the carriage and links 17 joining the eyes, thus providing a secure connection in the vertical direction, a second set of eyes on the carriage 6 and on the deck, offset in the direction of the rails and a diagonal link 18 joining the eyes, thus providing a secure connection in a horizontal direction parallel to the rails 5, and a third set of eyes on the carriage and on the deck, offset in a direction transverse to that of the rails and a diagonal link 19 joining the eyes, thus providing a secure connection in a horizontal direction transverse to the rails.

(13) The invention is not restricted to the above-described embodiments, which can be varied in a number of ways within the scope of the claims. In an example, the supports can also be slidingly attached to the carriages, enabling repositioning by unlocking the supports, sliding the supports to a new position e.g. along a beam of or a rail on the carriage, and again locking the supports to the carriage at the new position.