EP3243734A1

EP3243734A1 - Assembly of a vessel and a floating module

Info

Publication number: EP3243734A1
Application number: EP17169541.4A
Authority: EP
Inventors: Wouter Reinder van Dalen; Willem Jacob Van Der Velde; Richard Lunn; Matthijs Bastiaan Noordegraaf
Original assignee: Seaway Heavy Lifting Engineering BV
Current assignee: Seaway Heavy Lifting Engineering BV
Priority date: 2016-05-12
Filing date: 2017-05-04
Publication date: 2017-11-15
Anticipated expiration: 2037-05-04
Also published as: DK3243734T3; NL2016759B1; EP3243734B1; NL2016759A

Abstract

The present invention relates to an assembly of a vessel and a floating module. The vessel has a work deck extending in the longitudinal direction over at least 1/3 of the length of the vessel. The work deck has a width no larger than half the width of the vessel. The vessel further has a module support deck, at a lower level than the work deck, extending in the transverse direction from the work deck to a longitudinal access side section. The vessel further comprises a ballast system for controllably varying a draft of the vessel and a ballast control unit adapted to:
- lower the module support deck below water level to a connecting level for floating the module above the module support deck, and
- raise the module support deck and the floating module to an operational level that is higher than the connecting level.

Description

Field of the Invention

The present invention relates to an assembly of a vessel and at least one floating module provided on a module support deck of the vessel. The present invention further relates to a vessel and to a floating module for use in above described assembly.

Background

The field of offshore construction comprises the installation of structures and facilities in a marine environment, usually for the production and transmission of electricity, oil, gas and other resources. Such facilities may involve wind turbines that are installed offshore. In general, the installation of an offshore facility can be carried out either from an offshore platform standing on the sea floor or from a floating installation vessel.
In the field of installation vessels, different types can be distinguished, such as pipe laying vessels and heavy lift construction vessels (HLCV). The installation vessel can be a modular vessel to improve operating efficiency and flexibility. A modular installation vessel for various types of pipe laying operations is for example known from U.S. Pat. No. 8,087,369 , which discloses a modular ship complex including a basic vessel having a housing part provided with water height adjusting elements for varying the height of the waterline. The bottom of the housing part is formed by a platform that is moved between a raised position and a submerged position by operating the water height adjusting elements. The ship complex includes equipped floating modules suitable for being inserted into the housing and to be extracted from the housing when the platform is in the submerged position.
A disadvantage of above mentioned installation vessel is the relatively limited functionality of the vessel. The installation vessel can only be used for various types of J-lay or S-lay modules and is unsuitable for use in combination with floating modules of varying size or modules carrying relatively high super structures, such as cranes. Due to the fact that the modules need to be inserted into the housing part, the size of modules is limited to the opening in this housing. Furthermore, alignment of the modules with the sides of the housing part is difficult.
A further disadvantage of the above mentioned installation vessel is that the above mentioned floating modules have to be installed in a length direction via a last in-first out (LIFO) principle.

Object of the Invention

An object of the invention is to remedy the aforesaid drawbacks by providing an assembly of a vessel with at least one floating module having higher flexibility in functionality and positioning of the various types of floating modules for offshore installation and construction.
A further object of the invention is to provide a vessel which can receive a large variety of floating modules, such as pontoons, floating pile installation equipment or a floating sheerleg.
An even further object of the invention is to provide a vessel which has a large operating window and limited down time.
It is again an object of the present invention to provide an assembly of which the sailing and operating characteristics of the assembly can be adjusted and varied.

Summary of the Invention

This object is achieved by an assembly comprising a vessel and a floating module, the vessel comprising a bow, a stem and two longitudinal sides, the vessel having a length in a longitudinal direction and a width in a transverse direction. The floating module may for example be a sheerleg, monopile installation module, deep sea module, J-lay module, or S-lay module. The vessel has, along a first longitudinal side, a work deck extending in the longitudinal direction over at least 1/3 of the length of the vessel. The work deck has a width no larger than half the width of the vessel and a crane is provided on the work deck. The vessel further has a module support deck, at a lower level than the work deck, extending in the transverse direction from the work deck to a longitudinal access side section along the second longitudinal side and extending in the longitudinal direction from a longitudinal position on the vessel to a transverse access section that extends along the bow or stem in the transverse direction. The support deck has a width larger than half the width of the vessel. The vessel further comprises a ballast system for controllably varying a draft of the vessel with one or more water ballast tanks, one or more ballast pumps for pumping water into and out of the ballast tanks and a ballast control unit adapted to:

lower the module support deck below water level to a connecting level such that the longitudinal access side section and the transverse access section are submerged while the working deck level remains above water, for floating the module above the module support deck, and
raise the module support deck and the floating module to an operational level that is higher than the connecting level, such that the floating module is lifted by the module support deck.

The assembly as described above provides a work deck above water level along one side and a module support deck, at a lower level than the work deck, along another side. The assembly allows access to the module support deck along the longitudinal access side section and along the transverse access section for installing the module by floating the module over the module support deck.
Advantageously, introducing floating modules on the module support deck is simplified due to the fact that modules can be provided on the module support deck via the longitudinal access side section and the transverse access section. This increases flexibility of positioning the floating modules on the support deck. Furthermore, a large variety of differently sized or equipped modules can be lifted by the support deck. The support deck can receive modules of larger width than the support deck, while the support deck is at least half of the width of the vessel, and of larger length than the support deck, while the support deck is at least 1/3 of the length of the vessel. The open access sections provide the possibility of carrying modules with a width and/or length larger than the width and/or length of the module support deck. Also no height limitations for the suitable modules are imposed by the support deck. Moreover, the work deck provides access to the module during and after connection from the vessel with tools (cranes), winches, or via gangways for personnel, etc.
According to an embodiment, the crane is operable when the module support deck is under water. According to another embodiment, at least a second crane is present at the stem or the bow. According to a further embodiment, the second crane and the crane can automatically cooperate together when the module support deck is under water.
According to an embodiment, the present invention relates to an assembly of a vessel and a floating module, wherein the floating module has a height H and a width Wm that is smaller or larger by a length D of at least one meter than the width of the module support deck Ws, and wherein at least one longitudinal side of the module is situated at a distance Ds from the longitudinal access side that is larger or equal to the length D, wherein the ballast control unit is adapted to:

raise the module support deck and the floating module to a first operational level that is higher than the connecting level, over a distance that is lower than the height H, such that the floating module is lifted by the module support deck and a water line is formed by at least one longitudinal side of the module, and
operate the assembly with the floating module at the first operational level. Advantageously, the water line and hence seagoing properties are influenced by the width of the floating module. Furthermore, by having the floating module form part of the water line the operating properties are influenced.

In an embodiment of an assembly according to the present invention, the ballast control unit is adapted to:

raise the module support deck and the floating module to a second operational level such that the floating module is lifted out of the water by the module support deck, and
sail the assembly with the floating module at the second operational level. Advantageously, the floating module can be lifted completely out of the water, such that the sailing properties are influenced.

In an embodiment of an assembly according to the present invention, the width of the floating module Wm is larger than the width of the module support deck Ws. During operation of the assembly the waterline of the partly submerged module influences the stability of the assembly. This is especially useful for heavy lifting operations.
In another embodiment of an assembly according to the present invention, the module is of larger length than the module support deck and comprises a clamping member at its transverse bow end.
Larger modules can be provided on the support deck that project from the support deck of the bow. The modules can comprise for instance clamping members for the installation of monopiles. Thus the vessel can be equipped with monopile installation modules with an overhanging section in a longitudinal direction of the vessel in a rapid manner when required.
In a further embodiment of an assembly according to the present invention, at least one crane is placed on the work deck. Support of the module from the support deck is improved via the crane that allows for lifting heavy elements at the other side of the vessel, thus improving a working range.
In a further embodiment of an assembly according to the present invention, the crane is movable along a track extending along the work deck. Alternatively, multiple stationary working crane locations may be provided along the work deck. The flexibility of the work deck is really improved. By providing the crane movable on the work deck, it can be arranged differently. Furthermore, less cranes are required for reaching the same crane working area.
A pulling device may be placed on the work deck comprising a cable, attachable to the module for pulling the module into a connecting position over the module support deck. The positioning of the module is improved by pulling the module to its destination from the work deck, and connecting time is reduced due to the work-deck driven positioning of the module. For example, the pulling device may be a winch.
The work deck may be provided with positioning and fastening means, for guiding and fastening the module in a connection position.
By guiding the module to its connecting position, positioning of the module is improved and by fastening the module the module is kept at its connecting position.
Preferably the module is provided with complementary positioning means and fastenings means for engaging with the guiding and fastening means on the vessel. Connection of the positioning and fastening means to the modules is facilitated by the presence of their complementary means, thus reducing connection time, positioning time and down time of the assembly.
The module may comprise a lifting crane for lifting heavy objects from or to the assembly. The lifting crane on the floating module may be picked up in a harbor by the vessel, transported to an offshore position and can be operated at the offshore site. The floating lifting crane module may also be removed from the vessel to support the offshore installation operations independently from the vessel.
A module can be made of several smaller modules that are able to cooperate with the module support deck of the vessel.

Brief description of Drawings

The invention will by way of non-limiting example be explained in more detail below with reference to drawings in which illustrative embodiments thereof are shown. They are intended exclusively for illustrative purposes and not to restrict the inventive concept, which is defined by the appended claims.

Figure 1 shows a schematic perspective view of an embodiment of a vessel according to the invention;
Figure 2 shows a schematic perspective view of an embodiment of an assembly of a vessel according to figure 1 and a floating module according to in the invention; Figure 3 shows a schematic perspective view of the embodiment of figure 2 with the module in the operational level;
Figure 4 shows a schematic perspective view of a further embodiment of an assembly of a vessel according to figure 1 and a heavy lifting crane module according to the invention; and
Figures 5a, 5b and 5c show a schematic front view of an embodiment of an assembly with the module support deck at respectively a connecting level, a first operating level and a second operating level.

Detailed Description of Embodiments

Figure 1 shows a perspective view of a vessel 2 for use in an assembly 1 according to the invention. The vessel 2, having a length L in a longitudinal direction and a width W in a transverse direction, comprises a bow 20, a stem 19 and two longitudinal sides 3, 4. The length of the vessel L can range from 100-280 m, preferably the length of the vessel L is 220m. The width of the vessel W can range from 30-60 m, preferably the width of the vessel W is 50m.
Along a first longitudinal side 3, the vessel 2 is provided with a work deck 5. The work deck 5 has, in the longitudinal direction, a length Lw of at least 1/3 of the length of the vessel L and, in the transverse direction, a width Ww no larger than half the width of the vessel W. For example, the width of the work deck Ww can range from 10-30 m. The work deck 5 may extend in the longitudinal direction from a longitudinal position 21 near the bow 20 of the vessel to the stem 19.
Along a second longitudinal side 4, the vessel 2 is provided with a module support deck 6 at a lower level than the work deck 5. The height difference between the module support deck 6 and the work deck 5 can range from 5-15 m, preferably 10 m. The module support deck 6 extends in the transverse direction from a longitudinal access side section 8 provided along the second longitudinal side 4 to the work deck 5, wherein the support deck has a width Ws larger than half the width of the vessel W. The width of the module support deck Ws can range from 25-50 m. Furthermore, the module support deck 6 extends in the longitudinal direction from the longitudinal position on the vessel 2 to a transverse access section 9. The transverse access section 9 in this embodiment extends along the stem 19 in the transverse direction, but may also be located along the bow in another embodiment.
The vessel 2 further comprises a ballast system for controllably varying a draft of the vessel. The ballast system comprises one or more water ballast tanks 10, one or more ballast pumps 11 for pumping water into and out of the ballast tanks 10, and a ballast control unit 12.
The work deck 5 is provided with a crane 13. The crane 13 is configured to lift at least 1000 ton. The crane 13 may be movable along a track 14 extending along the work deck 5. A second crane 15 may be positioned at the stem or bow of the vessel.
The work deck 5 may be provided with a pulling device 16 placed on the work deck 5 comprising a pulling cable, attachable to a floating module 26 (see Fig. 3), for pulling the module into a connecting position over the module support deck 6.
The work deck 5 may be provided with positioning and fastening means 17, for guiding and fastening the module 26 in a connection position. For example, the positioning means can be a winch system, and the fastening means can be twist locks.
The vessel 2 may comprise an additional deck 7 provided with a bridge for controlling an overseeing vessel operations. The bridge may alternatively be provided on the work deck 5 to extend along the first longitudinal side 3.
Figure 2 shows a perspective view of an assembly 1, comprising a vessel 2 and a floating module 26. The floating module 26 comprises a floating body, e.g. a pontoon, having a height h in a vertical direction and a width Wm in the transverse direction of the vessel. The height of the floating body h can range from 1-20 m, preferably 2-15 m, more preferably 8 m. The width of the floating module Wm can range from 25m to 1.3 times the width of the work deck W.
The floating module 26 further comprises a monopile installation structure 29 for installing wind turbines provided on the floating body. A clamping device 27 for positioning the monopiles 30 is provided of the stem 19 of the module 31.
Complementary positioning and fastenings means 18 are connected to the floating body, wherein the complementary fastenings means 18 are adapted to releasably engage with the fastening means 17 for retaining the floating module 26 on the module support deck 6.
The floating module 26 may comprise propulsion means for independent propulsion of the floating module 26. The propulsions means can be connected to the floating body.
The floating module 26 may be provided with a heavy lifting crane and can in one embodiment comprise independent ballast means for controllably shifting ballast water within the module during lifting operations.
In an embodiment, the floating module 26 can be of larger length than the module support deck 6 and comprises a clamping member 27 at its transverse end. For example, the clamping member can be a pile clamp or a jacket clamp, a pipe laying stinger, a reel with clamp, a hand-over hand lowering mechanism.
During assembly, the floating module 26 can be pushed, pulled, or in any other way be positioned over the module support deck 6. For example, one or more tug boats 25 can be used to push the floating module 26 over the support deck, alternatively, or in addition, the floating module 26 can be pulled toward the work deck 5 via the pulling device 16.
Figure 3 shows a perspective view of an assembly 1 of a vessel 2 according to figure 1 and a monopile installation module. In this embodiment, the floating module 26 according to figure 2 is provided with a monopile installation structure 29, defining the monopile installation module. The monopile installation module comprises monopile receiving members 33 and a clamping member 27 for assisting in the installation of monopile. During use, the monopiles 30 are provided on the monopile receiving members 33. During installation, the monopiles 30 are lowered through the clamping member 27. The clamping member 27 assists in the positioning of the monopile 30. A ring shaped clamping member 27 limits the movement of the monopile part in all directions of a plane of the clamping member.
Figure 4 shows a perspective view of an assembly 1 of a vessel 2 according to figure 1 and a heavy lifting crane module. In this embodiment, the floating module 26 according to figure 2 is provided with a heavy lifting crane 28 for hoisting at least 8.000 ton, defining the heavy lifting crane module. The heavy lifting crane module comprise a lifting ballast system 24 for providing ballast during lifting operations.
The heavy lifting crane 28 may comprise movable hoisting means 32. The movable hoisting means 32 may be moved in a longitudinal direction of the heavy lifting crane module. When the heavy lifting crane 28 is placed near the stem of the module 31, than the range of the heavy lifting crane may be extended by moving the movable hoisting means 32 away from the module 26.
Figures 5a-c show a schematic front view of an assembly 1 according to any one of the figures 2-4. Figure 5a shows the assembly 1 with the module support deck 6 at a connecting level CL below water level WL. The ballast control unit 12 is adapted to lower the module support deck 6 below water level WL to the connecting level CL for floating the floating module 26 above the module support deck 6. At the connecting level CL, the longitudinal access side section 8 and the transverse access section 9 are submerged while the work deck 5 remains above water level WL.
Figure 5b shows the assembly 1 with the module support deck 6 at a first operating level OL1 below water level WL. The ballast control unit 12 may be adapted to raise the module support deck 6 and the floating module 26 to the first operational level OL1 that is higher (i.e. closer to water level) than the connecting level CL, over a distance that is lower than the height H, such that the floating module 26 is lifted by the module support deck 6 and a water line WLi of the module 26 is formed by at least one side 31, 34 of the module 26. At the first operating level OL1, the assembly 1 is configured to operate the assembly 1 with the floating module 26 on the module support deck 6.
Figure 5c shows the assembly 1 with the module support deck 6 at a second operating level OL2 that is situated above the water level WL. The ballast control unit 12 may be adapted to raise the module support deck 6 and the floating module 26 to a second operational level such that the floating module 26 is lifted out of the water by the module support deck 6. At the first operating level, the assembly 1 is configured to sail the assembly 1 with the floating module 26 on the module support deck 6.

Claims

Assembly (1) comprising a vessel (2) and a floating module (26), the vessel (2) comprising a bow (20), a stem (19) and two longitudinal sides (3, 4), the vessel (2) having a length L in a longitudinal direction and a width W in a transverse direction,
the vessel (2) being provided, along a first longitudinal side (3), with a work deck (5) extending in the longitudinal direction over at least 1/3 of the length of the vessel L, the work deck (5) having a width Ww no larger than half the width of the vessel W, and with a module support deck (6), at a lower level than the work deck (5), extending in the transverse direction from the work deck (5) to a longitudinal access side section (8) along the second longitudinal side (4) and extending in the longitudinal direction from a longitudinal position (21) on the vessel (2) to a transverse access section (9) that extends along the bow (20) or stem (19) in the transverse direction, the support deck (6) having a width Ws larger than half the width of the vessel W,
the vessel (2) further comprising a ballast system (10, 11, 12) for controllably varying a draft of the vessel with one or more water ballast tanks (10), one or more ballast pumps (11) for pumping water into and out of the ballast tanks (10) and a ballast control unit (12) adapted to:
- lower the module support deck (6) below water level to a connecting level (CL) such that the longitudinal access side section (8) and the transverse access section (9) are submerged while the working deck level remains above water, for floating the module above the module support deck (6), and

- raise the module support deck (6) and the floating module (26) to an operational level (OL1, OL2) that is higher than the connecting level, such that the floating module (26) is lifted by the module support deck (6),
wherein a crane (13) is provided on the work deck (5).
Assembly (1) according to claim 1, wherein the crane (13) is operable when the module support deck (6) is under water.
Assembly (1) according to claim 1, wherein at least a second crane (15) is present at the stem (19) or the bow (20).
Assembly (1) according to claim 3, wherein the second crane (15) and the crane (13) can automatically cooperate together when the module support deck (6) is under water.
Assembly (1) according to any of the preceding claims, wherein the floating module (26) has a height H and a width Wm that is smaller or larger by a length D of at least one meter than the width of the module support deck Ws, and wherein at least one longitudinal side of the module (3, 4) is situated at a distance Ds from the longitudinal access side (8) that is larger or equal to the length D, wherein the ballast control unit (12) is adapted to:
- raise the module support deck (6) and the floating module (26) to a first operational level (OL1) that is higher than the connecting level (CL), over a distance that is lower than the height H, such that the floating module (26) is lifted by the module support deck (6) and a water line (WLi) is formed by at least one longitudinal side of the module (34), and

- operate the assembly (1) with the floating module (26) at the first operational level (OL1).
Assembly (1) according to claim 5, wherein the ballast control unit (12) is adapted to:
- raise the module support deck (6) and the floating module (26) to a second operational level (OL2) such that the floating module (26) is lifted out of the water by the module support deck (6), and

- sail the assembly (1) with the floating module (26) at the second operational level (OL2).
Assembly (1) according to any of the preceding claims, wherein the crane (13) is movable along a track (14) extending along the work deck (5).
Assembly (1) according to any of the preceding claims, wherein a pulling device (16) is placed on the work deck (5) comprising a cable, attachable to the module for pulling the module into a connecting position over the module support deck (6).
Assembly (1) according to any of the preceding claims, wherein the work deck is provided with positioning and fastening means (17), for guiding and fastening the module in a connection position.
Assembly (1) according to claim 9, wherein the module (26) being provided with complementary positioning and fastenings means (18) for engaging with the positioning and fastening means (17) on the vessel.
Assembly (1) comprising a vessel (2) and a floating module (26), the vessel (2) comprising a bow (20), a stem (19) and two longitudinal sides (3, 4),
the vessel (2) being provided with a module support deck (6) extending to a longitudinal access side section (8) along a longitudinal side (3) over a length Ls of at least 0.3 times the length L and the module support deck (6) having a width Ws,
the floating module (26) being connected to the module support deck (6), wherein the floating module (26) has a height H and a width Wm that is smaller or larger by a length D of at least one meter than the width of the module support deck Ws, and wherein at least one longitudinal side of the module (34) is situated at a distance Ds from the longitudinal access side (8) that is larger or equal to the length D, wherein
the vessel (2) comprises a ballast system (10, 11, 12) for controllably varying a draft of the vessel with one or more water ballast tanks (10), one or more ballast pumps (11) for pumping water into and out of the ballast tanks (10) and a ballast control unit (12) adapted to:
- lower the module support deck (6) below water level to a connecting level (CL) for floating the module above the module support deck (6),

- raise the module support deck (6) and the floating module (26) to a first operational level (OL1) that is higher than the connecting level (CL), over a distance that is lower than the height H, such that the floating module (26) is lifted by the module support deck (6) and a water line (WLi) is formed by at least one longitudinal side of the module (34),

- operate the assembly (1) with the floating module (26) at the first operational level (OL1).
Assembly (1) according to claim 11, wherein the ballast control unit (12) is adapted to:
- raise the module support deck (6) and the floating module (26) to a second operational level (OL2) such that the floating module (26) is lifted out of the water by the module support deck (6), and

- sail the assembly (1) with the floating module (26) at the second operational level (OL2).
Assembly (1) according to any of the preceding claims, wherein the width of the floating module Wm is larger than the width of the module support deck Ws.
Assembly (1) according to any of the preceding claims, wherein the module is of larger length than the module support deck (6) and comprises a clamping member (27) at its transverse bow end (31).
Assembly (1) according to any of the preceding claims, wherein the floating module (26) adds a new function to the vessel (2).
Assembly (1) according to any of the preceding claims, wherein the module comprises a lifting crane (28).
Vessel (2) for use in an assembly (1) according to claim 1, comprising a bow, a stem and two longitudinal sides, the vessel (2) having a length L in a longitudinal direction and a width W in a transverse direction,
the vessel (2) being provided, along a first longitudinal side (3), with a work deck (5) extending in the longitudinal direction over at least 1/3 of the length of the vessel L, the work deck (5) having a width Ww no larger than half the width of the vessel W, and with a module support deck (6), at a lower level than the work deck (5), extending in the transverse direction from the work deck (5) to a longitudinal access side section (8) along the second longitudinal side (4) and extending in the longitudinal direction from a longitudinal position on the vessel (2) to a transverse access section (9) that extends along the bow or stem in the transverse direction, the support deck having a width Ws larger than half the width of the vessel W,
the vessel (2) further comprising a ballast system for controllably varying a draft of the vessel with one or more water ballast tanks (10), one or more ballast pumps (11) for pumping water into and out of the ballast tanks (10) and a ballast control unit (12) adapted to:
- lower the module support deck (6) below water level to a connecting level such that the longitudinal access side section (8) and the transverse access section (9) are submerged while the working deck level remains above water, for floating the module above the module support deck (6), and

- raise the module support deck (6) and the floating module (26) to an operational level that is higher than the connecting level, such that the floating module (26) is lifted by the module support deck (6),
wherein a crane (13) is provided on the work deck (5).
Vessel (2) according to claim 17, wherein the work deck (5) is provided with positioning and fastening means (17), for guiding and fastening the module in a connection position.
Vessel (2) for use in an assembly (1) according to claim 11, comprising a bow, a stem and two longitudinal sides,
the vessel (2) being provided with a module support deck (6) extending to a longitudinal access side section (8) along a longitudinal side over a length Ls of at least 0.3 times the length L and the module support deck (6) having a width Ws, wherein
the vessel (2) comprises a ballast system for controllably varying a draft of the vessel with one or more water ballast tanks (10), one or more ballast pumps (11) for pumping water into and out of the ballast tanks (10) and a ballast control unit (12) adapted to:
- lower the module support deck (6) below water level to a connecting level for floating a floating module (26) above the module support deck (6),

- raise the module support deck (6) and the floating module (26) to a first operational level that is higher than the connecting level, over a distance that is lower than the height H, such that the floating module (26) is lifted by the module support deck (6) and a water line is formed by at least one longitudinal side of the module,

- operate the assembly (1) with the floating module (26) at the first operational level,
wherein a crane (13) is provided on the work deck (5).
Floating module (26) comprising a working structure on its deck and comprising complementary positioning and fastening means (18), for guiding and fastening the module in a connection position on a module support deck (6) of a vessel.
Floating module (26) according to claim 20 the working structure comprising a heavy lifting crane (28).
Floating module (26) according to claim 20 or 21, the working structure comprising a clamping member (27).