NL2008456C2

NL2008456C2 - Improved reeling system.

Info

Publication number: NL2008456C2
Application number: NL2008456A
Authority: NL
Inventors: Cornelis Zandwijk
Original assignee: Heerema Marine Contractors Nl
Priority date: 2012-03-09
Filing date: 2012-03-09
Publication date: 2013-09-10
Also published as: WO2013133716A1

Description

P31077N L00/G EW/WH A Title: Improved reeling system Field of the invention

The present invention relates to an improved method for laying a pipeline at sea. The method involves the use of a pipeline laying vessel, a reel and a spooling assembly on land.

5 Prior art US4340322 discloses a conventional reeling vessel with a reel integrated in the vessel.

W02007120035 discloses a semi-submersible vessel comprising a reeling installation for reeling a pipeline with reels lifted on and off the vessel using an offshore crane.

W02009022170, in particular figures 7 and 11 thereof, discloses a system wherein a 10 floating reel is used to transport a section of pipeline from a source facility to a pipeline laying vessel.

Summary of the invention

The invention offers a solution for conventional reeling vessels as for instance shown in 15 US4340322. A disadvantage of these vessels is, that they can carry only one reel load from a source facility to an offshore pipelay location, requiring multiple trips between the source facility and the offshore pipelay location for re-loading the reel when a project requires more than one reel load to be laid.

In the invention, it was recognized that a problem is associated with the vessel of 20 W02007120035 in that it is problematic to lay long sections of pipeline. The vessel has three positions for reels on board: two positions at the end of a short pipeline construction ramp, where new pipeline sections are built up from pipe sections supplied to the pipelay vessel and spooled on the reels; and a third position in line with the pipelay tower from where the pipeline on the reel is reeled off to the seabed. A disadvantage of this pipelay process is that it is not 25 faster than that new pipeline sections can be built up in the two pipeline construction ramps. A transfer of an empty reel with the crane from the semi-submersible to an auxiliary vessel and a transfer of a full reel from an auxiliary vessel to the semi-submersible only permits a limited lift weight as dictated by the capacity of the crane and therefore only a limited length of pipe on one reel, after which the reel must be exchanged for a next one. This process was 30 recognized to be inefficient.

It was further recognized that the method according to W02009022170 is also quite complex and cumbersome. A complicated procedure is required to transfer the pipeline from the floating reel onto a reel positioned on board the vessel. This takes time and requires that -2- the pipeline is bent in an extra full bending cycle prior to the launching of the pipeline from the vessel. This decreases the quality of the pipeline, and may require increased thickness of the pipeline wall to ensure a pipeline with acceptable mechanical properties and fatigue life after installation. Furthermore, it was recognized that this transfer can only take place in calm 5 weather.

The invention aims to provide an improved method of laying a pipeline by a pipeline laying vessel which solves at least one of the mentioned problems.

The invention provides a method of laying a pipeline, the method comprising: - providing a reel, configured to float when loaded with a pipeline section, 10 - providing a spooling assembly, - providing a pipeline laying vessel comprising: o a reel driving device, o a pipeline guiding device, and o a docking station constructed to be coupled to the reel and uncoupled 15 from the reel when the reel is floating in the water, wherein the pipeline guiding device is constructed to guide the pipeline section along a trajectory from the reel when it is docked in the docking station towards the seabed, wherein the method comprises the further steps of: 20 - spooling said pipeline section onto said reel at said spooling assembly, transporting the reel to the pipeline laying vessel, couple the reel to the docking station of the pipeline laying vessel when the reel is floating in the water, laying a pipeline by: 25 o unspooling the pipeline from the reel in the docking station with said reel driving device, o guiding the pipeline through the pipeline guiding device, and o lowering the pipeline towards the seabed.

In an embodiment of the method, the docking station of the pipeline laying vessel 30 comprises couplings which are constructed to engage mating couplings on the reel, the couplings of the docking station being configured to constrain the reel in a horizontal and vertical direction, wherein the reel moves independently from the pipeline laying vessel before being docked and moves in unison with the pipeline laying vessel after being docked.

The movement in unison is advantageous when the pipeline is reeled from the reel and 35 launched from the vessel. If there are substantial relative movements between the reel and the vessel during the spooling of the pipeline from the vessel, multiple bending cycles may be -3- induced in the pipeline at the point where it leaves the reel, which can substantially reduce the quality and therefore the fatigue life of the pipeline.

In an embodiment of the method, the docking station comprises a reel moving device constructed for lifting the reel upward and/or pushing the reel downward into the water 5 relative to the hull of the pipeline laying vessel after the docking of the reel at the docking station, the method comprising lifting the reel upward or pushing the reel downward after engagement with the docking station, in order to increase the vertical forces between the reel and the pipeline laying vessel, and cause the reel to move with the vessel in unison.

In an embodiment of the method, the pipeline laying vessel comprises at least one 10 ballast tank for varying the draft of the pipeline laying vessel at least the docking station, the method comprising: docking the reel at the docking station, emptying or filling the ballast tank, thereby lifting the docking station and the reel or lowering the docking station and the reel, in order to increase the 15 vertical force between the reel and the pipeline laying vessel.

The vessel may be ballasted prior to engaging the reel, and de-ballasted after engaging the reel. In this way the reel is lifted over a distance. The vessel may also be de-ballasted prior to engaging the reel and ballasted upon engaging the reel. In this way, the reel is pushed down into the water.

20 In an embodiment of the method, after lifting the reel upward or pushing the reel downward, the reel remains partially submerged, wherein the pipeline section is spooled from the partially submerged reel during the pipeline laying operation. The generated buoyancy can be used either to reduce the required amount of lift force when the reel is lifted upwards, or to keep the reel firmly in place when it is pushed down Moreover, the buoyancy may carry 25 a part of the weight of the reel with pipe when the reel is partially submerged, thus reducing the vertical reaction forces between the reel and the vessel.

In an embodiment, the pipeline laying vessel comprises at least two arms which project from the hull over a horizontal distance and which define a docking space between them, the docking space being located outside the perimeter of the hull, the method 30 comprising positioning the reel in the docking space between the arms. The arms may be rigidly connected to the hull. The arms may be formed by beams.

In an embodiment of the method, the arms are adjustable to different angles in relation to the pipeline laying vessel, in order to accommodate for the height of the floating reel and resultant forces.

35 In an embodiment of the method, a reel driving device is provided on board the pipeline laying vessel and is engaged with the reel once the reel has been engaged in the -4- docking station and disengaged from the reel before the reel is disengaged from the docking station.

In an embodiment of the method, the reel driving device is supported on the pipeline laying vessel and movable between an engaged and a disengaged position. In the engaged 5 position the reel driving device is engaged with the reel, for instance a pinion wheel of the reel drive unit gripping into a rack on the circumference of a flange of the reel or a torsional device engaging with the axis of the reel. The reel driving device provides torque to the reel thus generating back-tension in the pipeline section when it is reeled off the reel.

In an embodiment of the method, the reel defines a reel axis and the reel is moved to 10 the pipeline laying vessel with the reel axis oriented vertically or horizontally.

In an embodiment, the method comprises providing a pipeline laying vessel having a reel path which extends over a horizontal distance, the method comprising moving the reel over said horizontal distance along the reel path relative to the pipeline laying vessel after the reel has engaged the pipeline laying vessel. The reel can be moved closer to the center of 15 gravity of the pipeline laying vessel, thereby reducing the amount of ballasting required from the vessel, so a heavier reel can be handled when the vessels is positioned at its operational draft.

In an embodiment of the method, the reel is not transported on a barge during the transportation thereof, but is self-floating.

20 In an embodiment of the method, the reel axis is rotated from a vertical orientation to a horizontal orientation just prior to docking the reel in the docking station of the spooling assembly. It may be advantageous to transport the reel with the reel axis oriented vertically, while it is advantageous to spool the pipeline section onto the reel when the reel axis is oriented horizontally.

25 In an embodiment of the method, the reel axis is rotated from a vertical orientation to a horizontal orientation just prior to docking the reel in the docking station of the pipeline laying vessel. It may be advantageous to transport the reel with the reel axis oriented vertically, while it is advantageous to spool the pipeline section from the reel and launch it to the seabed when the reel axis is oriented horizontally.

30 In an embodiment of the method, the pipeline vessel comprises a reel driving device constructed to be engaged with the reel once the reel is docked in the docking station, wherein the reel driving device provides back-tension to the pipeline when it is spooled off the reel.

The present invention further relates to a reel configured for holding a section of 35 pipeline spooled onto said reel, the reel further comprising: -5- at least one buoyancy compartment configured for providing buoyancy to said reel, the buoyancy being configured to maintain the reel at least partially above the water line when the reel is loaded with a pipeline section, one or more couplings constructed for coupling the reel to mating couplings of 5 a docking station of a pipeline laying vessel.

In an embodiment, the reel is configured to float when fully loaded with a pipeline section.

In an embodiment of the reel, the couplings are configured to transfer forces in the direction of the X-axis, Y-axis and Z-axis between the pipeline laying vessel and are 10 constructed to cause the reel to move in unison with the pipeline laying vessel in the X- direction, Y-direction and Z-direction, while allowing a rotation of the reel about its reel axis.

The couplings of the reel may be formed by the protruding ends of the axle of the reel.

The couplings of the docking station may be formed by pivot points which are constructed to accommodate the protruding ends of the axle of the reel.

15 The couplings of the reel may also be formed by a hollow reel axis having open holes at its ends. In this case, the coupling of the docking station may be formed by pins which fit into the holes of the hollow axis.

In an embodiment of the reel, a valve mechanism is included to allow for water into or out of ballasting compartments in the reel, to account for the change in the Z-direction forces as 20 the pipe is reeled or un-reeled.

The present invention further relates to a pipeline laying vessel comprising: a docking station which is constructed to be coupled to a reel and be uncoupled from the reel when the reel is loaded with a pipeline section and floating in the water, 25 - a reel driving device configured for rotating the reel in the docking station, and a pipeline guiding device, the pipeline guiding device being constructed to guide the pipeline section along a trajectory from the reel towards the seabed when the reel is docked in the docking station.

The pipeline is directly launched, i.e. without being spooled onto an intermediate reel. 30 In an embodiment, the pipeline laying vessel comprises a reel moving device constructed for lifting the reel upward relative to the hull or pushing the reel downward into the water relative to the hull hull after the docking of the reel at the docking station, in order to increase the vertical forces between the reel and the pipeline laying vessel and to cause the reel and the pipeline laying vessel to move in unison.

35 In an embodiment of the pipeline laying vessel, the docking station comprises at least one arm configured to carry the reel, the arm being pivotably connected to the hull via a -6- hinging connection between the arm and the hull, and an actuator for pivoting the arm and the reel which is attached to it about the hinging connection relative to the hull.

In an embodiment of the pipeline laying vessel, the docking station comprises at least one ramp constructed to engage the reel in the floating condition and wherein the reel moving 5 device is configured for moving the reel upwards along the ramp.

In an embodiment, the pipeline laying vessel comprises at least two arms which project from the hull over a horizontal distance and which define a docking space between them into which in use the reel is docked, wherein the arms are rigidly connected to the hull of the vessel, wherein the arms are constructed to carry the full weight of a reel loaded with 10 pipeline when the reel is provided entirely above the water.

In an embodiment, the pipeline laying vessel comprises at least two arms which project from the hull over a horizontal distance and define a docking space between them into which the reel may be docked, wherein the angle of the arms relative to the pipeline laying vessel is adjustable.

15 In an embodiment, the rigid arms comprise guidance and connection means for axes of the reel, which allow for movement of the reel along the angled arms and therefore control the height of the reel in the water.

In an embodiment, the pipeline laying vessel is a monohull vessel.

In an embodiment, the pipeline laying vessel is a semi-submersible vessel, and the 20 docking station is provided below a deck of the semisubmersible vessel, wherein a path is provided to allow the pipeline section to travel from the docking station to the pipeline guiding device.

In an embodiment of the pipeline laying vessel the docking station is provided above a lower hull section of the semi-submersible vessel, the docking station being configured to 25 carry the reel between the lower hull section, the deck structure and left and right columns of the semi-submersible vessel.

In an embodiment, the pipeline laying vessel comprises at least one ballast tank for varying the draft of the vessel at least at the location of the docking station.

In an embodiment, the docking station is configured to support the reel in a partially 30 submerged position, and wherein the pipeline guiding device is configured to spool the pipeline section from the partially submerged reel during a pipeline laying operation.

In an embodiment, the docking station comprises one or more couplings which are constructed to be coupled to and uncoupled from mating couplings on the reel, and which are constructed to support the reel and to transfer forces from the vessel to the reel and vice 35 versa, in order to cause the reel to move in unison with the pipeline laying vessel.

-7- ln an embodiment, the reel includes pinions that extend from its axes that are coupled to couplings on the rigid arms of the vessel. The couplings are capable of moving along the rigid arms to adjust for changing buoyancy forces, including during pipelay.

The present invention further relates to a spooling assembly configured for spooling a 5 pipeline section onto a reel, the spooling assembly comprising: - a spooling trajectory comprising at least one support which is constructed to support the pipeline section which is to be spooled onto the reel, wherein the at least one support is constructed to allow the pipeline section to slide or roll towards the reel, 10 - a docking station configured for receiving the reel, wherein the docking station comprises a reel support structure configured for receiving the reel and configured for holding the reel, the reel support structure comprising a rotary device which allows the reel to rotate during the spooling of the pipeline section onto the reel.

15 - a back-tensioning device for providing back-tension to the pipeline section when it is spooled on to the reel.

In an embodiment, the docking station of the spooling assembly is configured to hold the reel in a partially submerged position during the spooling of the pipeline section onto said reel.

20 In an embodiment, the docking station of the spooling assembly is configured to engage the reel when the reel is in a floating condition.

In an embodiment, the reel support structure is constructed to allow the reel to move upwards or downwards while maintaining the reel stationary in a horizontal direction.

In an embodiment, the docking station of the spooling assembly comprises a reel 25 tilting device constructed for tilting the reel axis from vertical to horizontal or vice versa.

In an embodiment, the docking station of the spooling assembly comprises a dock comprising walls and a door, the dock being configured for providing a confined space in which a water level is variable, wherein the docking station is configured to hold the reel in said confined space during the spooling of the pipeline onto the reel.

30 In an embodiment, the back-tensioning device is engaged with the pipeline section being spooled on to the reel at a position along the spooling trajectory, preferably near the reel being spooled.

The present invention further relates to a combination of: - a pipeline laying vessel according to any of claims 12-23, 35 - a reel according to any of claims 10-11, and - a spooling assembly according to any of claims 24-29.

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Brief description of the drawings

The previous and other features and advantages of the present invention will be more fully understood from the following detailed description of exemplary embodiments with reference to the attached drawings. Like reference numerals refer to like parts.

5

Figure 1 shows a schematic side view of a pipeline laying vessel according to the prior art.

Figure 2 shows a diagram in top view showing the logistics of a pipeline laying method using exchangeable reels and auxiliary vessels for transport of the reels.

10 Figure 3a shows a side view of a reel according to the invention in an unloaded state.

Figure 3b shows a side view of a reel according to the invention in a loaded state.

Figure 4a shows a side view of another reel according to the invention in an unloaded state.

Figure 4b shows a side view of another reel according to the invention in a loaded state. 15 Figure 5 shows a side view of a reel positioned at a spooling assembly according to the invention.

Figure 6 shows a side view of a reel loaded with pipeline according to the invention being towed by a vessel.

Figure 7 shows a side view of a pipeline laying vessel according to the invention.

20 Figure 8 shows a side view of an unloaded reel according to the invention being towed by a vessel.

Figure 9 shows a side view of a spooling assembly according to the invention.

Figure 10 shows a side view of another spooling assembly according to the invention.

Figure 11 shows a side view of yet another spooling assembly according to the 25 invention.

Figures 12a, 12b, 12c, 12d, 12e, 12f show in side view a sequence of loading an unloaded reel with a pipeline section in another embodiment of the spooling assembly according to the invention.

Figures 13, 14, 15, 16, 17 show in side view different methods of transporting a full reel 30 to a pipeline laying vessel.

Figure 18 shows in side view a pipeline laying vessel according to the invention.

Figure 19 shows in side view an embodiment of the docking station of the pipeline laying vessel of figure 18.

Figure 20 shows in side view another embodiment of the docking station of the pipeline 35 laying vessel of figure 18.

Figure 21 shows in side view yet another embodiment of the docking station of the pipeline laying vessel of figure 18.

-9-

Figures 22a shows in side view another embodiment of a pipeline laying vessel according to the invention

Figures 22b shows in top view the pipeline laying vessel of figure 22a.

Figures 23a, 23b, 23c, 23d show in side view a sequence of operational steps for 5 docking a reel in a docking station of the pipeline laying vessel of figures 22a, 22b.

Figure 23e shows in side view another embodiment of a pipeline laying vessel according to the invention.

Figure 24a shows in side view another embodiment of a pipeline laying vessel according to the invention 10 Figure 24b shows a front view of the embodiment of figure 24a.

Figures 25a, 25b, 25c, 25d and 25e show in side view a sequence of operational steps for docking a reel in a docking station of the pipeline laying vessel of figures 24a, 24b.

Figure 26 shows an embodiment of the reel driving device.

Figure 27 shows an example of how the driving power can be applied to the reel.

15

Detailed description of the figures

Turning to figure 1, a conventional reeling vessel 1 is shown which contains a reel 2 which can rotate about an axis 3. The axis 3 is fixedly connected to the hull 5 of the reeling vessel 1 via a reel foundation structure 4. A pipeline 6 is spooled on the reel 2 and deployed 20 through a body of water 8 to the seabed 9 via a pipelay ramp 7. A reeling vessel like this is described in for instance patent US4340322.

A disadvantage of such a reeling vessel is that once the entire pipeline section on the reel has been deployed to the seabed, the vessel has to sail back to a shore base for re-filling the reel with pipe. As a result, the expensive conventional reeling vessel is only about one-25 third of its time effectively deploying pipe to the seabed, the other two-thirds being spent in sailing to the shore, re-filling the reel and sailing back to the offshore location.

Turning to figure 2, an alternative to conventional reeling is a process working with lifted reels. A pipeline laying vessel 10 is provided with a pipelay tower 7, a crane 11 and one or more reel positions 12.

30 Full reels 13a are transported from a spool base 20 to the pipeline laying vessel 10 using one or more transport vessels 14. At the pipeline laying vessel, the one or more full reels 13a are lifted onto the pipeline laying vessel 10 using the crane 11. Each full reel is placed onto a full reel position 12a. For reeling the pipeline 6 from the reel 12 to the seabed 9, the reel is brought to the operating reel position 12b. From this position 12b, the pipeline 6 on 35 the operating reel 13b is led through the pipelay tower 7 and deployed to the seabed 9. Once the operating reel 12b is empty, it is moved to an empty reel position 12c. From there, the empty reel 13c is lifted by the crane 11 and placed on a transport vessel 14. The reel - 10- positions 12a for a full reel 13a, 12b for an operating reel 13b and 12c for an empty reel 13c may be different positions, but may also be one and the same position. In the latter case, the full reel 13a is placed immediately in the operating reel position 12b by the crane 11, hooked up to the pipelay tower 7, reeled off, where after the empty reel 13c is removed from the 5 operating reel position 12b by the crane 11. The empty reel 13c is sailed back to the spool base 20 on a transport vessel 14.

An advantage of the lifted reels concept over the conventional way of reeling is that the expensive pipeline laying vessel 10 can be kept in the field on a continuous program of reeling. Transport and spooling are done using one or more transport vessels 14 which 10 together have a lower day rate than the pipeline laying vessel 10.

A disadvantage of the lifted reels concept is that an offshore crane is required on the pipeline laying vessel 10, making the pipeline laying vessel 10 more complicated and expensive than the conventional reeling vessel 1. Moreover, a series of transport vessels 14 is needed for transporting the reels 13 between the spool base 20 and the pipeline laying 15 vessel 10.

Figures 3a, 3b, 4a, 4b show various embodiments of a reel 30 floating on a body of water 8. In the reeling process, a section of pipeline 25 is plastically deformed over a reel 30. During this process the cross-section of the pipeline is deformed to an oval shape or a substantially oval shape. In order to keep the oval deformation within acceptable limits, the 20 maximum plastic strain in the pipeline is not allowed to exceed a value of 2 to 2.5%. As a result, the shown reel for spooling on a rigid pipeline has a relatively large diameter. For instance, for a 16 inches (0.4 meters) diameter pipeline section 25, the drum 31 of the reel 30 has a minimum diameter of 16 to 20 meters. As the pipeline section 25 is spooled on the reel 30 in several layers, the flanges 32 have an even considerably larger diameter than the drum 25 31.

The drum and flanges of the reel are constructed as a closed structure, i.e. with a hollow space 130 (or compartment) inside which is filled with air and in use does not become filled with water. The reel 30 generates sufficient buoyancy to keep itself afloat in a body of water 8, even when loaded with a section of pipeline 25. Depending on the ratio between the 30 reel width W and the reel diameter D, the reel will float on the water surface 33 with a substantially horizontal reel axis 35 as shown in Figures 3a and 3b or with a substantially vertical reel axis 35 as shown in Figures 4a and 4b. In Figures 3a and 4a, the reel 30 is shown in its empty reel floating position 34a; in Figures 3b and 4b in its full reel floating position 34b.

35 It may even occur that at a certain ratio of W and D the reel floats with a substantially vertical reel axis 35 as shown in Figure 4a when empty and with a substantially horizontal reel axis 35 as shown in Figure 3b when loaded with a section of pipeline.

-11 -

Turning to figures 5, 6, 7, 8, in an embodiment, the invention involves a method of applying floating reels in the process of: - spooling a section of pipeline 25 on a reel 30 at the quayside 28 of a spool base 20 (also referred to as spooling assembly) as shown in Figure 5, 5 - transporting the full reel 30 from the spool base 20 to the pipeline laying vessel 10, for instance by means of a tug 40 and a towing line 41 as shown in Figure 6, - engaging the full reel 30 with the pipeline laying vessel 10, whereby the position of the reel 30 is fixed with respect to the vessel 10 and the reel 30 free to rotate about its axis 35 as shown in Figure 7, 10 - disengaging the empty reel 30 from the pipeline laying vessel 10 and transporting it back to spool base 20, for instance by a tug 40 and towing line 41 as shown in Figure 8. When the empty reel is disengaged, it can be replaced by a full reel immediately.

An advantage over W02009022170 is that prior to the launching of the pipeline from the vessel, the pipeline only needs to be bent once around a reel and thus has a higher 15 quality, i.e. less strain cycles are imparted onto the wall of the pipeline.

Another advantage is that a time gain is obtained, because the coupling of the reel to the vessel is much faster than the transfer of the entire pipeline section from the intermediate reel to the reel on board the vessel.

Turning to figures 9, 10 and 11a number of variants of a spool base 20 and a method 20 of spooling a pipeline section 25 on to a floating reel 30 are shown. The spool base 20 comprises a docking station 100 where an empty reel 30 can be docked. The spool base 20 comprises a support 140 for supporting the pipeline section 25 and a back-tensioning device 150 for providing back-tension to the pipeline section 25 during spooling..

In Figure 9, a reel 30 is shown with a natural floating position with the reel axis 35 25 parallel to the water surface 33. The reel 30 is attached to a movable reel support structure 36 of the docking station 100. The movable reel support structure 36 is movable in a vertical direction along a rail system 37. The reel support structure 36 provides a horizontal fixation between the reel 30 and the quayside 28, holding the reel 30 within the reel spooling position 15; in vertical direction the reel 30 floats freely on the water surface 33 between an empty reel 30 floating position 34a and a full reel floating position 34b. The reel support structure 36 may support the reel 30 at its axis 35, but may also be engaged with the reel in another way. A reel drive unit 38 is provided, preferably between the reel support structure 36 and the reel 30 for driving the reel during the spooling of the section of pipeline 25.

A feature of the solution shown in Figure 9 is that a relatively deep harbor basin is 35 required, with a water depth in the same order as the diameter of the reel 30, in order to prevent the reel 30 in its full reel floating position 34b from touching the bottom of the harbor 29.

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Figure 10 shows a spooling variant whereby the reel 30 is supported by a floating body 42. The floating body 42 reduces the vertical distance between the empty reel floating position 34a and the full reel floating position 34b and thus also the required water depth of the harbor basin. The floating body 42 may support the reel 30 at its axis 35, but may also 5 support it otherwise, for instance by an arrangement of rollers supporting the reel at its circumference. Despite the floating body 42, the reel remains partially submerged, even when empty. In this way, the center of gravity is kept low.

Figure 11 shows a spooling variant for a reel 30 which has a natural floating position with the reel axis 35 perpendicular to the water surface 33. The reel is attached to a movable 10 reel support structure 36 vertically moving along a rail system 37. The reel support structure 36 provides a horizontal fixation between the reel 30 and the quayside 28, holding the reel 30 within the reel spooling position 15.

In the vertical direction, the reel 30 floats freely on the water surface 33 between an empty reel floating position 34a and a full reel floating position 34b. The reel support structure 15 36 may support the reel 30 at its axis 35, but may also be engaged with the reel in another way, for instance by a system of rollers supporting the bottom flange of the reel. A reel drive unit 38 is provided, preferably between the reel support structure 36 and the reel 30 for driving the reel during the spooling of the section of pipeline 25. Spooling a section of pipeline 25 on a reel 30 which is floating flat on the water surface 33, i.e. with its axis 35 oriented 20 vertically and perpendicular to the water surface 33, has the disadvantage that the bending point 16 where the section of pipeline 25 is bent over the reel 30 is often underwater, in particular when the reel is almost full and having a deep draft in the water. Another disadvantage of this spooling variant is that the trajectory of the section of pipeline 25 may require a recess 39 in the quayside for the section of pipeline to be spooled from the spooling 25 firing line 26 on the quayside 28 on to the reel 30 floating partly under the surface of water 33.

Turning to Figure 12, an embodiment is shown for spooling a reel 30 with a natural floating position 34 which is flat on the surface of water 53, i.e. with a vertical reel axis. When a spooling operation starts, the reel 30 is brought in an upright floating position 55, i.e. with a reel axis oriented horizontally, with the result that the bending point 16 of the section of 30 pipeline 25 over the reel 30 is always above water.

A dock 50 is provided in a harbor basin near a quayside 20. The dock 50 has a door 51. Figure 12a shows the situation that the door 51 is open, ensuring that the water level 52 inside the dock is equal to the water level 53 in the harbor basin. A reel 30 floating at its empty reel floating position 34a flat in the water can be moved into the dock 50. In Figure 12b 35 the reel is shown inside the dock with the door 51 closed. The water level 52 inside the dock is raised to a level at which the reel can be overturned to a vertical empty reel floating position 55a (having a horizontal reel axis) without touching the bottom of the dock 59. The - 13- overturning operation can be carried out by ballasting specific ballast compartments inside the reel 30; or with the aid of a lifting arrangement 54 connected to a crane on the quayside which is known per se as shown in Figure 12b; or by another method.

Figure 12c shows the situation that the reel 30 is lowered onto a reel support 5 structure 56 on the bottom of the dock 59 by gradually lowering the water level 52 in the dock and keeping the reel in its vertical empty reel floating position 55a by means of the lifting arrangement 54 attached to a crane or by another method. The reel support structure 56 as drawn supports the reel on a collar 60 protruding from the flange of the reel; it will be evident that this support can be created at several places, for instance at the axis of the reel 35 or at 10 the outer rim of the flange or at another place, and can also be a movable support as shown in Figure 9.

In Figure 12d, a reel drive unit 57 is shown between the reel support 56 and the collar 60. This reel drive unit 57 may comprise a number of driven rollers. The reel drive unit may be realized in various different manners, for instance as shown in Figures 9, 10 and 11 15 or otherwise. The driven rollers may also be sprocket wheels or otherwise. The reel drive unit 57 is used for rotating the reel 30 when spooling a section of pipeline 25 on to the reel at the reel spooling position 15. During spooling, a back-tensioning device 150 is providing back-tension to the section of pipeline 25 in order to cause the pipeline to plastically bend over the reel 30 at the bending point 16.

20 Figure 12e shows the situation that the reel 30 is full. The reel 30 is subsequently lifted from its support structure 56 by raising the water level 52 inside the dock. The reel is kept in its vertical full reel floating position 55b by means of the lifting arrangement 54 attached to a crane or otherwise. The reel 30 is now moved from its spooling position 15 to the reel overturning position 58. The reel overturning position 58 may be a position different 25 from the reel spooling position 15, but may also be the same position. The water level 52 inside the dock is raised to a level that the underside of the reel 30 in its vertical full reel floating position does not touch the bottom of the dock 50 during the overturning operation.

Figure 12f shows the reel 30 after it has been overturned to its natural horizontal full reel floating position 34b. This overturning operation is done by de-ballasting the specific 30 ballast compartments which were previously filled with water when the empty reel was overturned from horizontal to vertical; or with the aid of the lifting arrangement 54 attached to a crane; or otherwise. After overturning, the water level 52 inside the dock is lowered to the water level 53 in the harbor basin, where upon the door 51 is be opened and the reel 30 is floated out of the dock 50.

35 Figures 13 to 17 show a number of embodiments for the transport of a floating reel 30. Figure 13 shows a reel 30 with a natural full reel floating position 34b towed by a tug 40 and a towing line 41, with the reel axis oriented horizontal and perpendicular to the towing - 14- direction 43. The towing line may be attached to the axis 35 of the reel 30, but may also be attached elsewhere to the reel.

Figure 14 shows a same configuration for transporting the reel as Figure 13, i.e. with a horizontal reel axis, but now with the reel axis 35 parallel to the towing direction 43.

5 Figure 15 shows a transport embodiment for a reel 30 with a natural full reel floating position 34b with the reel axis oriented vertically. The towing line 41 is shown attached to the reel flange 32; the towing line may also be attached elsewhere to the reel.

Figures 16 and 17 show transport embodiments wherein the reel 30 is transported in combination with the floating body 42 used for spooling (as shown in Figure 10). In Figure 16, 10 the reel 30 is towed with the reel axis 35 perpendicular to the towing direction 43. In Figure 17 the reel axis 35 is oriented parallel to the towing direction 43.

It will be clear that the embodiments for transporting an empty reel from a pipeline laying vessel back to a spool base are similar, with a difference that the reel 30 then floats at an empty reel floating position 34a instead of at a full reel floating position 34b.

15 Figure 18 shows a pipeline laying vessel 10 and a method for connecting the reel 30 to the pipeline laying vessel. The vessel 10 comprises a docking station 200 at one end thereof. The docking station 200 is configured to engage the reel at least at two points on the reel.

The floating reel 30 arrives at the docking station 200 of the pipeline laying vessel at 20 a full reel floating position 34b. The docking station comprises a reel moving device 70 which is engaged with the reel 30, for instance at the reel axis 35. The reel 30 comprises one or more couplings 102 which engage mating couplings 104 on the reel moving device 70. The reel moving device 70 is also denoted as a reel lifting device 70.

Subsequently, the reel moving device 70 lifts the reel 30 out of the water or partly out 25 of the water to an active reeling position 80. Once positioned in the active reeling position 80, a reel driving device 160 is engaged with the reel and the section of pipeline 25 on the reel hooked up to the pipelay ramp 7 via the pipe arc 81. The reel driving device 160 is constructed to rotate the reel or to provide back tension when the reel is rotated by pulling the pipeline section from the reel by tensioners 99 on the pipelay tower 7.

30 The pipelay ramp 7 is also denoted as a pipeline guiding device and defines a firing line as is known in the field of the art. In the pipelay ramp 7, the section of pipeline 25 is connected to the pipeline 6 and further deployed to the seabed 9, the reel driving device 160 providing back-tension to the pipe arc 81 during deployment. The engagement procedure may take place at sea after the reel 30 has been towed to the pipeline laying vessel as shown 35 in Figures 13 to 17. However, it will be evident that the engagement procedure may also be carried out at the spooling location 15 near the quayside.

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Figures 19 and 20 show two possible embodiments of the reel moving device 70. In Figure 19, the reel 30 is (partly) lifted above the water surface 33 until it moves in unison with the pipeline laying vessel 10. It will be understood that the movement in unison relates to the heave, roll and pitch motions, and does not preclude the reel to be rotated relative to the 5 vessel in order to spool the pipeline from the reel.

Movement in unison prevents huge bumping forces between the reel 30 and the pipeline laying vessel 10 and prevents uncontrolled length changes in the pipe arc 81 which may cause fatigue damage and even local buckling of the section of pipeline 25 at the bending point 16. As an example, the reel moving device 70 may comprise a fixed support 10 structure 71, a hingeable arm 72 hinging about a hinge 73 and a pulling member 74. The reel connection point 75 is brought underneath the protruding ends of the axis 35 of the reel floating in the full reel floating position 34b, where upon the length of the pulling member 74 is shortened and the reel 30 is (partly) lifted above the water surface 33 until the reel has reached the active reeling position 80. The pulling member may be a hydraulic cylinder, a 15 wire, a bundle of wires or different.

Figure 20 shows an alternative reel moving device 70 suited for pushing the reel 30 deeper underwater, until the contact force between the reel connection point 75 and the reel axis 35 generated by the buoyancy of the reel is high enough for the reel 30 to move in unison with the pipeline laying vessel 10.

20 Figure 21 shows an embodiment of the reel moving device 70 in the form of a ramp structure 76 with a ramp 77. A reel carriage 78 is brought underneath the reel axis 35 when the reel is in a full reel floating position 34b. After engagement, the reel carriage 78 with the reel 30 is pulled up the ramp 77 by means of a pulling system 79, until the reel has reached the active reeling position 80 which may be partly or entirely above the water surface 33. The 25 pulling system 79 may be a hoisting system, a system of hydraulic cylinders, a rack and pinion system or otherwise.

Figures 22a, 22b show another embodiment of a pipeline laying vessel 10 with a floating reel 30. The pipeline laying vessel 10 comprises a hull 5 in the form of a flat barge, equipped with two cantilever arms 90, and a pipelay ramp 7. The reel 30 can be engaged with 30 the pipeline laying vessel 10 via a ramp structure 76 mounted on the cantilever arms 90. On each cantilever arm 90, a reel carriage 78 can be moved over the ramp 77 of the ramp structure 76. The moving mechanism may be a hoisting system, a system of hydraulic cylinders, a rack and pinion system or otherwise. Between the arms 90, a docking space 122 is defined. The docking space is located outside the perimeter 124 of the hull.

35 At the active reeling position 80, a reel driving device 160 is engaged with the reel 30, whereupon the section of pipeline on the reel is hooked up via the pipe arc 81 to the pipelay ramp 7 for deployment to the seabed 9.

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Figures 23a-23d show the procedure of engaging the floating reel 30 with the pipeline laying vessel 10. The reel 30 is brought to the pipeline laying vessel 10 or the pipeline laying vessel 10 is brought to the reel 30 after it has been spooled at the spooling position 15. Figure 23a shows the situation just before the engagement procedure is started.

5 The reel is at a full reel floating position 34b. The reel carriage 78 is moved to the farthest end of the ramp 77.

In Figure 23b it is shown how the pipeline laying vessel 10 is ballasted to an inclined draft by filling specific ballast compartments 110 inside the pipeline laying vessel 10 with water. The reel carriage 78 is brought underneath the axis of the reel 35. Figure 23c shows 10 how the reel is partly lifted above the water surface 33 by de-ballasting the pipeline laying vessel 10 and decreasing the angle of inclination 92. The ultimate position 82 to which the reel 30 can be lifted out of the water is determined by the strength of the cantilever arms 90. After the ultimate position 82 has been reached, the reel carriage 78 is moved towards the hull 5 of the pipeline laying vessel 10, simultaneously further de-ballasting the pipeline laying 15 vessel 10 until it has reached a position at which the deck 91 is parallel to the water surface 33. During this operation, the reel 30 is further lifted above the water surface 33; the ratio between the position of the reel 30 on the ramp 77 and the angle of inclination 92 of the pipeline laying vessel 10 is limited by the strength of the cantilever arms 90 and of the hull 5.

At the active reeling position 80, a reel driving device 160 is engaged with the reel 20 30, whereupon the section of pipeline on the reel is hooked up via the pipe arc 81 to the pipelay ramp 7 for deployment to the seabed 9.

Figure 23e shows an embodiment of the pipeline laying vessel, wherein the angle of the rigid arms 90 is controllable using a device 138 and set to a preferred angle. Each arm 90 comprises a movable pivot point 136 which accommodates a protruding reel axis and is 25 situated in a cam track 134, thereby allowing the moving of the reel along the cam track. The reel moving device 70 is configured to move the reel along the cam track 134. When in use the vessel is oriented at an angle to the horizontal, the moving of the reel along the cam track changes the height of the reel in the water, compensating for the changes in buoyancy force during reeling which the reel exerts on the arms 90.

30 Figures 24a and 24b show an embodiment of a pipeline laying vessel 10 in the form of a semisubmersible vessel. The semisubmersible vessel comprises a floater or a system of floaters 93, a system of columns 94 and a deck box 95 which defines the deck 114. During transits, the vessel sails at a draft not deeper than the height of the floaters 93. During operations, the vessel sinks itself to a draft somewhere halfway the height of the columns 94. 35 This working draft can be varied substantially.

The docking station 100 is positioned below deck 114. A floating reel 30 is placed on a reel support structure 56 comprising pivot points 67. At the active reeling position 80, a reel driving - 17- device 160 is engaged with the reel 30. From the active reeling position 80, the section of pipeline 25 on the reel is hooked up in the form of a pipe arc 81 through an opening 96 in the deck box 95 to the pipelay ramp 7 and connected to the pipeline 6, where upon the pipeline 6 is further deployed to the seabed 9. An assembly 116 of an aligner and straightener is 5 provided at the top of the pipelay ramp 7 to bend the pipe section 25 from the pipe arc 81 to the firing line of the pipelay ramp 7 and to straighten the pipeline. Aligners and straighteners are well known from the prior art.

Figure 24b shows a front view of the semisubmersible pipeline laying vessel 10 at a draft at which the reel 30 floats freely between the reel support structures 56 and reel drive 10 units 57.

Figures 25a-25e show a procedure for engaging and disengaging a floating reel 30 with a semisubmersible pipeline laying vessel 10. The reel 30 is brought to the pipeline laying vessel 10 or the pipeline laying vessel 10 is brought to the reel 30 after it has been spooled at the spooling position 15.

15 Figure 25a shows the situation just before the engagement procedure is started. The reel is at a full reel floating position 34b. The semisubmersible pipeline laying vessel 10 comprises an arrangement of ballast compartments 110 which can be used for successively increasing the draft by filling ballast compartments with water or decreasing the draft by discharging water out of ballast compartments. The semisubmersible pipeline laying vessel 20 10 is ballasted to a draft 97a at which the reel support structure and reel drive unit are entirely below the axis of the reel 35 and the underside of the deck box 95 is above the reel 30. With the pipeline laying vessel 10 in this position, the reel is moved between the columns 94 and the reel support 56 with reel drive units 57 (as shown in Figure 24b) until the axis of the reel 35 is above the reel support structure 56.

25 Figure 25b shows how the pipeline laying vessel 10 is de-ballasted to a draft 97b at which the reel support structures 56 and reel drive units 57 are engaged with the axis of the reel 35.

Figure 25c shows how the pipeline laying vessel 10 has been further de-ballasted to a draft 97c at which the reel has reached the active reeling position 80. Preferably, the active 30 reeling position 80 of the reel 30 is higher above the surface of water 33 than the empty reel floating position 34a, such that the reel 30 always exerts a downward reaction force on the reel support structures 56 and reel drive units 57. With the pipeline laying vessel 10 at a draft 97c and the reel at the active reeling position 80, the reel driving device 160 can be engaged with the reel and the section of pipe 25 hooked up to the pipelay ramp 7 and connected to the 35 pipeline 6 being deployed to the seabed 9.

Figure 25d shows how the pipeline laying vessel 10 is ballasted to a draft 97d at which the reel 30 just reaches the empty reel floating position 34a. At this draft the reel 30 is - 18- about to be disengaged with the reel support structure 56 and reel drives 57. In Figure 25e, the pipeline laying vessel 10 is further de-ballasted to a draft 97e, at which the reel can be moved from between the columns 94, the reel support structures 56 and the reel drives 57.

Figure 26 shows an embodiment of the reel driving device 160. A floating reel 30 is 5 engaged with a reel support structure 56 in its active reeling position 80. A reel driving device 160 is provided between the hull 5 of the pipelay vessel and the reel 30. The reel driving device 160 is movable between an engaged position 161 and a disengaged position 162. In the engaged position 161, the reel driving device 160 provides torque to the reel 30 as required to maintain a specific amount of back-tension in the pipe arc 81. This back-tension is 10 maintained when releasing the fixation of the end of the section of pipeline 25 from the reel and during reeling off the pipeline from the reel, in order to prevent the pipeline from relaxing on the reel.

Figure 27 shows an example of how the driving power can be applied to the reel 30. The reel driving device 160 may comprise a hydraulic motor 163 driving a pinion wheel 164.

15 In the engaged position 161, the pinion wheel 164 is engaged with a rack 166 mounted on the reel flange 32. It will be clear to an experienced person that the reel driving motors may also be electric motors or otherwise.

It will be obvious to a person skilled in the art that the details and the arrangement of the parts may be varied over considerable range without departing from the scope of the 20 claims.

Claims

A method for laying a pipeline (6), the method comprising: providing a coil (30) adapted to float when it is wrapped with a pipeline part (25), providing a winding device (20) Providing a vessel for laying a pipeline, the vessel comprising: o a coil drive device (160), o a pipeline guide device (7) for the pipeline, and o a docking station (200) adapted to - when the coil floats in the water - to be coupled to the coil and to be disconnected from the coil, the pipeline guiding device (7) being arranged to displace the pipeline part (25) from the coil (30) along a path to the seabed to be guided when the coil is coupled to the docking station, the method comprising the further steps of: rinsing said pipeline part (25) on said coil (30) at said winding device (20), transporting the coil to the pipeline laying vessel, 20. connecting the coil to the docking station of the vessel for laying a pipeline when the coil floats in the water, laying a pipeline by: o unwinding the pipeline from the spool in the docking station with the aid of said spool drive device, 25. guiding the pipeline through the pipeline guide device, and o lowering the pipeline to the seabed.

2. Method as claimed in claim 1, wherein the docking station comprises couplings (104) which are adapted to engage corresponding couplings (102) on the coil, wherein the couplings (104) of the docking station are arranged to engage the coil to hold a horizontal and vertical direction, wherein the coil moves independently of the pipeline laying vessel before it is coupled to the docking station and moves integrally with the pipeline laying vessel after the coil is coupled with the docking station. 35-20

Method as claimed in claim 1 or 2, wherein the docking station comprises a coil movement device (70) which is adapted to lift the coil in an upward direction and / or press the coil downwards in the water in a downward direction direction relative to the hull of the vessel for laying a pipeline, the method comprising lifting the coil in an upward direction or pressing downward in a downward direction after the coil has been brought into contact with the docking station to increase the vertical forces between the coil and the pipeline vessel and to cause the coil to move as a whole with the vessel. 10

Method according to one of the preceding claims, wherein the pipeline vessel comprises at least one ballast tank (10) for varying the draft of the vessel for laying a pipeline at at least the docking station, the method comprising: 15. coupling the spool to the docking station, ballasting or deballasting the ballast tank, wherein the docking station and the spool is moved up or down in order to increase the vertical force between the spool and the vessel for laying to enlarge a pipeline and to ensure that the coil moves as a whole with the vessel 20.

5. Method as claimed in claim 3 or 4, wherein after lifting the coil or pressing the coil down, the coil remains partially submerged, and wherein the pipeline part is unwound from the partially submerged coil during the laying operation of the pipeline.

Method according to one of the preceding claims, wherein the pipeline vessel comprises at least two arms (90) which project from the hull (5) over a horizontal distance (120) and which have a docking space (122) ) between the arms 30, wherein the docking space is located outside the periphery (124) of the hull, the method comprising positioning the coil in the docking space between the arms.

The method of any one of the preceding claims, wherein the coil defines a coil axis (35) and wherein the coil is moved to the vessel for laying a pipeline 35 with the coil axis oriented in a horizontal or vertical direction. -21 -

A method according to any one of the preceding claims, comprising providing a vessel for laying a pipeline with a coil path (76) extending over a horizontal distance, the method comprising moving a coil over said horizontal distance along the coil path with respect to the vessel for laying a pipeline after the coil has been brought into contact with the vessel for laying a pipeline.

A method according to any one of the preceding claims, wherein the coil is not transported on a tray during transport thereof, but is self-floating. 10

10. A coil adapted to hold a pipeline member wound on said coil, the coil further comprising: at least one buoyancy compartment (130) adapted to provide buoyancy to said coil, the buoyancy compartment being arranged to hold the coil at least partially above the waterline when the coil is loaded with a pipeline part (25), one or more couplings (102) adapted to couple the coil with corresponding couplings (104) of a docking station (200) of a vessel for laying a pipeline.

The coil of claim 10, wherein the couplings (102) are adapted to transfer forces in the direction of the X-axis, Y-axis and Z-axis between the coil and the vessel for laying a pipeline and its constructed to cause the coil as a whole with the pipeline vessel to move in the X direction, Y direction, and Z direction, while allowing rotation of the coil about its coil axis (35).

12. A pipeline laying vessel, comprising: a docking station (200) constructed to be coupled to a coil and to be disconnected from the coil when the coil is loaded with a pipeline part and floats in the water , a coil drive device (160) adapted to cause the coil to rotate in the docking station and a pipeline guide device (7), the pipeline guide device being constructed about the pipeline part (25) along a path from the coil (30) in the direction of the seabed when the coil is coupled to the docking station. -22-

A pipeline laying vessel according to claim 12, wherein said path between the coil and the seabed is continuous, without passing through an intermediate coil.

A pipeline laying vessel according to claim 12 or 13, wherein the vessel comprises a coil movement device (70) constructed to move the coil upwardly with respect to the hull or move the coil in a downward direction direction with respect to the hull and in the water, after coupling the coil with the docking station, to increase the vertical forces between the coil and the pipeline vessel 10 and to ensure that the coil and the move a pipeline vessel as a whole.

A pipeline laying vessel according to any of claims 12-14, wherein the docking station (200) comprises at least one arm (72) adapted to support the coil 15 (30), the arm pivotable is connected to the roller via a hinged connection (73) between the arm (72) and the hull (5), and wherein the docking station (200) comprises an actuator (74) for pivoting the arm and the coil associated therewith is attached about the hinged connection (73) relative to the hull.

A pipeline laying vessel according to any of claims 14-15, wherein the docking station (200) comprises at least one ramp (77) that is constructed to make contact with the coil when it is in a floating state and wherein the coil movement device (70) is adapted to move the coil upwards along the ramp. 25

A pipeline-laying vessel according to any of claims 12-16, wherein the vessel comprises at least two arms (90) protruding from the hull over a horizontal distance (120) and a docking space (122) between them define in which the coil is received during operation, the arms (90) being rigidly connected to the hull of the vessel, the arms being constructed to support the full weight of a coil loaded with a pipeline when the coil as a whole is provided above the water.

A pipeline laying vessel according to any of claims 12-16, wherein the vessel comprises at least two arms projecting from the hull over a horizontal distance and defining therebetween a docking space in which the coil can be received, wherein the angle of the arms relative to the vessel for laying a pipeline is adjustable. -23-

A pipeline laying vessel according to claim 17 or 18, wherein the rigid arms each comprise a rail such as a rail for a cam constructed to accommodate the axes of the coil, the rails a movement of the coil make it possible to move along the arms at an angle and thus control the height of the coil in the water, the coil movement device being configured to move the coil along the rails. 10

A vessel for laying a pipeline according to any of claims 12-19, wherein the vessel is a mono-hull vessel.

A pipeline laying vessel according to any of claims 12-20, wherein the vessel is a semi-submersible vessel, the docking station being provided under a deck (114) of the semi-submersible vessel, a path (96) is provided along which the pipeline member can move from the docking station to the pipeline guide device (70).

A pipeline laying vessel according to claim 21, wherein the docking station (200) is provided above a lower hull portion (93) of the semi-submersible vessel, the docking station being arranged to support the coil (30) between the lower hull part (93), the deck structure (95) and left and right columns (94) of the semi-submersible vessel. 25

A pipeline laying vessel according to any of claims 12-22, comprising at least one buoyancy compartment (110) for varying the draft of the vessel near at least the docking station.

A pipeline laying vessel according to any of claims 12-23, wherein the docking station is adapted to support the coil in a partially submerged position, and wherein the pipeline guiding device is adapted to remove the pipeline part from the partially submerged coil to be wound during a pipeline laying operation. 35

A pipeline laying vessel according to any of claims 12-24, wherein the docking station (200) comprises one or more couplings (104) adapted to be coupled to, and disconnected from, corresponding couplings (102) on the coil, and which are adapted to support the coil and transfer forces from the vessel to the coil and vice versa, to allow the coil to be integral with the vessel for laying a pipeline to move. 5

26. Winding device adapted for winding a pipeline part on a spool, the winding device comprising: a winding path (21) comprising at least one support (140) adapted to wrap the pipeline part (25) to be wound on the spool supporting, wherein the at least one support is adapted to cause the pipeline member (25) to slide or roll toward the coil, a tensile stress device (140) for supplying a tensile stress to the pipeline member (25) during winding, docking station (100) adapted to receive the coil 15 (30), the docking station comprising a coil support structure (36) adapted to receive the coil (30) and adapted to hold the coil, wherein the coil support structure comprises a rotary device that causes the coil to rotate during winding of the pipeline member on the coil. 20

The winding device of claim 26, wherein the docking station (100) is adapted to hold the coil in a partially submerged position during the winding of the pipeline portion on said coil.

The winding device of claim 26 or 27, wherein the docking station is adapted to contact the coil when the coil is in a floating state.

29. Winding device according to any of claims 26-28, wherein the coil support structure (36) is constructed to cause the coil to move up or down during the winding of the pipeline on the coil, while keeping the coil stationary in a horizontal direction.

30. Winding device according to any of claims 26-29, wherein the docking station comprises a coil tilting device (54) that is constructed for tilting the coil shaft (35) from vertical to horizontal or vice versa. -25-

A winding device according to any of claims 26-30, wherein the docking station comprises a dock comprising walls and a door, the dock being adapted to provide a shielded space in which a water level is variable, the docking station being arranged to keep the coil in said space during the winding of the pipeline on the coil.

A combination of: a pipe laying vessel according to any of claims 12-15, a coil according to any of claims 10-11, and a winding device according to any of claims 26-31.