The present invention relates to a fluid transfer structure for transfer of fluid to and/or from a landbased structure or a floating structure to a floating structure.

When a fluid is transferred from a floating structure to and/or from another floating vessel or a landbased structure, one or more floating conduits are routinely used. This may for example be transfer of LNG between an LNG-carrier and a floating or non-floating storage facility for LNG, or supply of fuel, for example LNG, to a vessel, such as a ferry, cruise-ship, container ship and other types of vessels, that is moored at a pier or similar structure where there is a fuel storage facility. A problem with conduits that are arranged on the seabed is that it is susceptible to damage. Another problem is that it is relatively inflexible in its use since it cannot be readily moved. Such conduits are also costly to install. Furthermore, installation, inspection and maintenance of the conduit is much more cumbersome when the conduit is arranged on the seabed.

Alternatively, floating pipes can be used to transfer fluid between a floating structure and a landbased structure or another floating structure. Such floating pipes are also susceptible to be damaged, especially in harbours where ships are constantly travelling to and from the harbour and may run over the floating pipe. Between operations, when the floating pipe is not used to transfer fluid, floating pipes will usually have to wound up on a reel onshore to avoid obstruction of other vessels travelling where the floating pipe is located when it is used to transfer fluid. Such pipes, like subsea conduits, are also very costly.

Alternatively, hoses can be used to bunker LNG (Liquified Natural Gas) or other fluid fuels from the quay and directly to the vessel. This works for some applications, but due to safety there is a certain clearance that needs to be maintained between the location where bunkering takes place, and non-authorized personnel, vehicles and other ignition sources. This is often a hinderance for doing cargo operations, like transfer of goods or personnel, while the vessel is bunkering. This means that the two operations often cannot be performed at the same time, which is very costly for the vessel operator.

From prior art it is known, from WO 2015/112134 Al, to provide a conduit system to transfer fluid from a marine vessel to an offshore rig. The conduit system comprises several straight, buoyant conduits and flexible tubing elements that connect the straight, buoyant conduits. The whole conduit therefore floats on the surface of water when it is used to transfer fluid. The conduit system is stored on the marine vessel and travels with the marine vessel between fluid transfer operations. The marine vessel thereby has a properly dimensioned conduit system for transfer of fluid at any port it may arrive. A storage configuration of the conduit system at the stern of the marine vessel is shown in figures 3 and 4 while figure 5 illustrates deployment of the conduit system.

In US 8,584,290 B2 there is disclosed a walkway between two installations separated by water, typically between a ship and a pier as illustrated in the figures of the patent. The walkway is intended as a bridge for people to allow them to walk between the ship and the pier and may also be used to transport goods. The walkway comprises several sections that are rotatably connected to floating elements that are provided with horizontal and vertical segments. The walkway comprises two types of floating elements, a first type of floating element that has segments that rotate relative to a vertical axis and a second type of floating element that has segments that rotate relative to a horizontal axis. When the walkway is not in use it can be folded up.

An objective of the present invention has been to obtain an improved system or structure for transfer of fluid between a floating structure and a landbased structure or another floating structure.

It has further been an objective to obtain a system or structure that can be quickly moved between an idle or storage position where it is not obstructing sea traffic and an operational position where it is fluidly connecting a floating structure and a landbased structure or another floating structure.

It has also been an objective to obtain a fluid transfer structure or structure that does not obstruct the traffic of ships, boats and other vessel in the harbour area where the fluid transfer structure is located, when it is non-operating, i.e. between fluid transfer operations.

It has also been an objective to obtain a fluid transfer structure that is suitable both for transfer of a cargo fluid, such as e.g. LNG, or for bunkering of a cargo fluid, such as e.g. LNG, on the outside of the vessel, while the vessel is moored to a quay, hence avoiding interference with or disturbance of other cargo operations which can then be performed during bunkering operations.

These objectives have been achieved by the fluid transfer structure as defined in independent claim 1 and a use of the fluid transfer structure as defined in claim 21. Further embodiments of the fluid transfer structure have been defined in the dependent claims 2-20.

The present fluid transfer structure enables bunkering of a fluid, such as e.g. LNG, between a floating unit, such a ship, and tanks located onshore in a non-floating facility and/or offshore on a floating facility and eliminates the need for a dedicated bunker barge or vessel for LNG fueling of vessels. The present fluid transfer structure may comprise a single platform connected to the non-floating or floating facility with a bridge section. The present fluid transfer structure may also comprise series of one or more platforms connected by an appropriate number of bridge sections in order to create a continuous fluid transfer structure. The platforms are preferably floating by providing them with at least one buoyancy element each. The outer most platform acts as a fueling platform preferably comprising aerial conduits, or loading arms, that can be releasably connected to the floating unit for transfer of fluid between the floating unit and the non-floating or floating facility. The other platforms are intermediate platform units that act as a pivot points for the bridge sections and may be provided with sufficient buoyancy to support the bridge sections that extend between and are attached to the platforms. Optionally, the bridge sections may also be provided with buoyancy elements or chamber to provide some or all the necessary buoyancy to keep the bridge sections floating. The intermediate platform unit that is arranged adjacent to the non-floating or floating facility, preferably supports a ramp type bridge section to the non-floating or floating facility. The bridge section or bridge sections preferably comprises/comprise both a personnel gangway and at least one separate pipe rack for one or more cargo pipes and optionally other tube elements, such as e.g. utility pipes and control cables.

When the fluid transfer structure is not in use (i.e. the fluid transfer structure is in an idle mooring position), it is preferably arranged such that the bridge section or bridge sections lie roughly parallel to the non-floating or floating facility. If the fluid transfer structure comprises two or more bridge sections, the bridge sections are preferably arranged in a folded, idle position such that the bridge sections lie next to one another and roughly parallel to the non-floating or floating facility, typically a quay as mentioned above. When a vessel is berthed, the outermost platform moves out past the stern and an intermediate platform unit may also move out from its inshore position. The bridge section arranged adjacent to the non floating or floating facility, for example a quay, is preferably roughly perpendicular to the quay and is long enough to position an intermediate platform unit outboard of the vessel’s side. The outermost platform unit is positioned next to the vessel’s side and an attachment system, for example a vacuum attachment system, preferably attaches the outer platform unit to the vessel. One or more aerial conduits, for example an LNG hose, or loading arm(s), is/ are thereafter connected to the vessel’s manifold. The aerial conduit(s) could be cooled down before the fluid transfer operation begins, if required. When the fluid transfer is completed, the aerial conduit(s) is/are disconnected and the LNG in the cargo line can be evacuated if required. Finally, the fluid transfer structure moves back to its idle mooring position. To effect the moving of the fluid transfer structure between its idle position and its operating position and vice versa, at least one of the platforms are provided with at least one thruster unit, for example by means of electric drives which are steered from a control room that can be located on the outer fueling platform, or from onshore, or remotely from the vessel. The fluid transfer structure can thereby be positioned as desired. The steering system may be a manual hydraulic system similar to systems used on work boats and fishing vessels. Alternatively, the fluid transfer structure may be provided with hydraulic actuation, i.e. conventional piston/cylinder assemblies, or a system of cog wheels to effect the moving of the fluid transfer structure between its idle position and its operating position and vice versa.

Hence, there is provided a fluid transfer structure for transfer of fluid across a body of water with a surface, between a floating unit and a non-floating or floating facility, where the fluid transfer structure comprises:

- an outer platform unit which is configured to be releasably attached to the floating unit,

- at least one bridge section arranged between the outer platform unit and the non-floating or floating facility when the fluid transfer structure is in an operative position, and

- at least one cargo pipe which at one end is configured to be fluidly connected to a pipe element on the non-floating or floating facility and in the other end to be fluidly connected to an aerial conduit on the outer platform unit.

The at least one bridge section comprises a support structure and the at least one cargo pipe comprises at least one cargo pipe section which is mounted on the support structure of the at least one bridge section. The fluid transfer structure is further provided with buoyancy such that the at least one cargo pipe is located above the surface of the body of water when the fluid transfer structure is operative.

The support structure is preferably substantially rigid and may for example comprise a trusswork formed by a desired number of steel beams securely attached to each other, for example by welding or with bolts. The at least one cargo pipe section is preferably securely mounted on the support structure of the bridge section. It should be mentioned that any number of pipe and/or hose elements may be arranged and securely mounted on the bridge section. The outer platform unit is preferably arranged at an end portion of the at least one bridge section and the at least one bridge section is preferably attached to the outer platform unit, preferably with one or more joint elements allowing relative movements, especially relative rotations, to take place between the bridge section and the outer platform unit.

The non-floating or floating facility typically comprises one or more fluid tanks located onshore, i.e. a non-floating facility, but the fluid tanks may also be located on a floating vessel, such as a bunker barge or vessel. The facility with the fluid tanks are typically, although not necessarily, located on or near a quay or a pier or a similar structure.

The floating unit may be a transport ship that transports a fluid, for example an LNG-carrier, or a boat that needs to bunker, for example a ferry, a cruise ship, a container ship or other types of vessels. If the floating unit is an LNG-carrier, fluid is transferred from the floating unit to or from the non-floating or floating facility. On the other hand, if the floating unit is a ferry, a cruise ship or another type of vessel that needs to bunker fuel, then fluid is transferred from the non-floating or floating facility to the floating unit.

The fluid transfer structure comprises at least one bridge section that extends directly from the non-floating or floating facility or from a pier or a quay that the non-floating or floating facility is arranged on or near or some distance from, to an outer platform unit that is arranged at the end of the at least one bridge section. As will be described in more detail below, the fluid transfer structure may also comprise a plurality of bridge sections where two adjacent bridge sections are connected to each other with an intermediate platform unit. A fluid transfer structure comprising a plurality of bridge sections, also extends directly from the non-floating or floating facility or from a pier or a quay that the non-floating or floating facility is arranged on or near or some distance from, to an outer platform unit that is arranged at the end of the outermost of the plurality of bridge sections.

The outer platform unit is preferably provided with one or more buoyancy elements or buoyancy chambers such that the support structure is mostly or completely located above the water surface and the at least one cargo pipe is located above the water surface. Alternatively, the at least one bridge section may be provided with buoyancy elements. As will be described in more detail below, if the fluid transfer structure comprises a plurality of bridge sections, where two adjacent bridge sections are connected to each other with an intermediate platform unit, one or more of the bridge section may also be provided with one or more buoyancy element(s) in addition to the outer platform unit. In addition, one or more of the bridge sections may be provided with buoyancy elements.

As mentioned, preferably the outer platform unit and/or the at least one bridge section of the fluid transfer structure is provided with at least one buoyancy element and/or at least one buoyancy chamber providing buoyancy to the fluid transfer structure such that the at least one cargo pipe of the fluid transfer structure is located above the surface of the body of water when the fluid transfer structure is operative. It should be noted that preferably the entire at least one cargo pipe is located above the surface of the body of water which means that inspection, regular maintenance and repair is much easier to carry out. The outer platform unit preferably comprises a pipe system to which the at least one cargo pipe and the aerial conduit is fluidly connected. The pipe system preferably comprises at least one valve device for control of fluid flow through the at least one cargo pipe and the aerial conduit. The pipe system preferably also comprises at least one emergency shut down valve device for emergency shut down of fluid flow through the at least one cargo pipe and the aerial conduit. The aerial conduit, which connects the pipe system on the outer platform unit with the floating unit, is preferably permanently connected to the pipe system and stored on the outer platform unit when it is disconnected from the floating unit. Alternatively, the aerial conduit is disconnected from the outer platform unit when the fluid transfer structure is not in use and stored on the floating unit or at some other suitable location.

The outer platform unit is preferably provided with at least one thruster unit for propulsion of the fluid transfer structure between a storage position and an operating position. Alternatively, as mentioned above, the fluid transfer structure may be provided with a hydraulic actuation assembly, i.e. conventional piston/cylinder assemblies, or a system of cog wheels to effect the moving of the fluid transfer structure between its idle position and its operating position and vice versa.

In the storage position, the at least one bridge section is preferably located such that it will interfere as little as possible with other activities that may take place in the vicinity. Typically, the at least one bridge section will be arranged substantially parallel to the pier or quay on which the non-floating or floating facility is located, when it is in the storage or idle position. If the fluid transfer section comprises a plurality of bridge sections, the adjacent bridge sections preferably lie lengthwise next to each other in the storage position to minimize the impact on other activities that may take place in the vicinity.

The fluid transfer structure preferably comprises attachment means for releasable attachment of the outer platform unit to the floating unit. The attachment means may comprise at least one vacuum pad and/or at least one electromagnetic attachment element for releasable attachment of the outer platform unit to the hull of the floating unit. The attachment means is/are preferably securely attached to the outer platform unit. The attachment means may further be configured to restrict some of the relative motions between the outer platform unit and the floating unit and allowing other relative motions to take place. This is known in the art and will not be further described herein.

As an alternative, the attachment means may also comprise a rope system for releasable attachment of the outer platform unit to the hull of the floating unit. The rope system preferably comprises at least one rope that is permanently or removably attached to the outer platform unit. The rope system is preferably self-tensioning.

A further alternative to using at least one vacuum pad and/or electromagnetic pad, the at least one thruster unit may be used to keep the outer platform unit in position during fluid transfer, i.e. the thruster unit is part of a dynamic positioning system.

The at least one bridge section, or the outermost bridge section if the fluid transfer structure is provided with a plurality of bridge sections, is preferably rotatably attached to the outer platform unit by using a joint device. The attachment of the at least one bridge section, or the outermost bridge section if the fluid transfer structure is provided with a plurality of bridge sections, to the outer platform unit preferably allows for relative rotation in three degrees of freedom between the outer platform unit and the at least one bridge section or the outermost bridge section if the fluid transfer structure is provided with two or more bridge sections. Such an attachment between the at least one bridge section, or the outermost bridge section, may be achieved by using a joint device as mentioned, for example, a ball joint. The outer platform unit may obviously be releasably attached to the at least one bridge section.

Alternatively, the outer platform unit and the at least one bridge section, or the outermost bridge section if the fluid transfer structure is provided with a plurality of bridge sections, that is connected to the outer platform, may be made as a single unit.

The fluid transfer structure may further comprise at least one free hanging, U- shaped and flexible cargo pipe element to compensate for relative motions between the at least one bridge section, or the innermost bridge section if the fluid transfer section is provided with a plurality of bridge sections, and the non-floating or floating facility, where the cargo pipe element is fluidly connected to the at least one cargo pipe and is configured to be fluidly connected to a pipe element on the non-floating or floating facility. This configuration of the fluid transfer structure is particularly useful, for example, to compensate for tidal movements or wave motions in the water.

As briefly mentioned above, the fluid transfer structure may comprise at least one intermediate platform unit, that is arranged between the non-floating or floating facility and the outer platform unit, and at least one additional bridge section that is arranged such that a bridge section extends between the outer platform unit and the at least one intermediate platform unit, another bridge section extends between the non-floating or floating facility and the at least one intermediate platform unit, and, if the fluid transfer structure comprises two or more intermediate platform units, another bridge section extends between any two adjacent, intermediate platform units. Two adjacent intermediate platform units should be understood here as two intermediate platform units that are connected with a bridge section, i.e. two intermediate platform units which are connected to either end of the bridge section.

Preferably, the at least one intermediate platform unit and/or the outer platform unit support all bridge sections of the fluid transfer structure such that the at least one cargo pipe of the fluid transfer structure is located above the surface of the body of water when the fluid transfer structure is operative. As mentioned, the entire at least one cargo pipe is located above the surface of the body of water since the fluid transfer structure is provided with buoyancy. Preferably, the outer platform unit and/or one or more of the intermediate platform units comprises at least one buoyancy element such that sufficient buoyancy to keep the at least one cargo pipe above the water surface is achieved. It should also be mentioned that usually the at least one bridge section, or the innermost bridge section if the fluid transfer structure comprises a plurality of bridge sections, is also connected to the non floating or floating structure and therefore to a certain degree supported by the non floating or floating structure.

The at least one intermediate platform unit and/or the outer platform unit may be provided with at least one buoyancy element to support and keep the fluid transfer structure floating. Alternatively, the at least one bridge section may be provided with one or more buoyancy elements that may provide all or some of the necessary buoyancy to the fluid transfer structure, i.e. the at least one bridge section may be provided with buoyancy in addition to the outer platform unit and/or any intermediate platform unit or the at least one bridge section may be provided with all the buoyancy of the fluid transfer structure.

The at least one cargo pipe of the fluid transfer structure preferably comprises a connecting cargo pipe section that is arranged on the at least one intermediate platform unit and that is fluidly connected to the two cargo pipe sections arranged on each of the two respective bridge sections that are connected to the at least one intermediate platform unit. If the fluid transfer structure comprises a plurality of intermediate platform units, i.e. three or more bridge sections, preferably each of the intermediate platform units comprises a connecting cargo pipe section that is fluidly connected to the two cargo pipe sections arranged on each of the two respective bridge sections that are connected to the respective intermediate platform units. The connecting cargo pipe section is preferably flexible such that it can be bent to a desired degree during use and when the fluid transfer structure is being moved between the storage position and the operating position.

Preferably, each of the bridge sections are rotatably attached to the at least one intermediate platform unit with respective joint devices. In practice, it is preferably the support structures of the bridge sections that are connected to the at least one intermediate platform unit. The fluid transfer structure may further comprise a rotational control mechanism which compels the support structures of the two bridge sections connected to the at least one intermediate platform unit to follow equal angular movements in opposite clockwise directions in a horizontal plane relative to the at least one intermediate platform unit. Such a rotational control mechanism may be included to avoid S-shaped bending of any one of the flexible connecting cargo pipe sections of the at least one intermediate platform unit when the bridge sections rotate relative to the at least one intermediate platform unit. The rotational control mechanism may, for example, comprise a system of cogwheels interconnecting the two support sections of their respective bridge sections and the intermediate platform unit and causing the support structures of the two bridge sections connected to the at least one intermediate platform unit to follow equal angular movements in opposite clockwise directions in a horizontal plane relative to the at least one intermediate platform unit.

Furthermore, the two bridge section are preferably connected to the at least one intermediate platform unit such that the distance between respective end portions of the at least one cargo pipe section on each of the two bridge sections is substantially constant when the two bridge sections, and thereby the at least one cargo pipe section on each of the two bridge sections, are rotated horizontally relative to the intermediate platform unit. An advantage of this arrangement is to minimize bending and wear of the flexible cargo pipe element between the two adjacent bridge sections.

As mentioned above, the intermediate platform unit may comprise at least one thruster unit. The at least one thruster unit may be provided for propulsion of the fluid transfer structure between a storage position and an operating position. The at least one thruster unit may be provided for use in dynamic positioning system to keep the outer platform unit in a desired position relative to the floating unit during transfer of fluid. Alternatively, the fluid transfer structure may be provided with hydraulic actuation, i.e. conventional piston/cylinder assemblies, or a system of cog wheels to effect the moving of the fluid transfer structure between its idle position and its operating position and vice versa.

The at least one bridge section may be provided with at least one pipe rack. The at least one pipe rack may be provided for support of one or more cargo pipes and/or other tubular elements, for example utility pipes and/or various types of electric and signal cables. In addition, the at least one bridge section is preferably provided with a gangway for personnel that extends besides the at least one pipe rack. Thereby, operators will have easy access to the at least one cargo pipe and other tubular elements and cables arranged in the at least one pipe rack for inspection, maintenance and repair of the at least one cargo pipe and the other tubular elements and cables.

The at least one cargo pipe section mounted on the at least one bridge section is preferably a substantially rigid pipe. The at least one rigid pipe element preferably extends along substantially the entire length of the support structure. Alternatively, the entire at least one cargo pipe may be formed as a single, continuous flexible pipe.

A typical use of a fluid transfer structure according as described above and below, will be for transfer of LNG between a non-floating or floating facility and a floating unit or for bunkering of a vessel. Another use of the fluid transfer structure may be for bunkering of various types of vessels, such as ferries, cruise ships and so on.

Other features and advantages of the invention will appear from the following description of preferred, non-limiting embodiments of the invention, with reference to the figures where:

Figure 1 illustrates schematically a top view of a first embodiment of a fluid transfer structure according to the present invention seen in an idle position where the fluid transfer structure comprises an outer platform unit and a single bridge section that is rotatably attached to a pier.

Figure 2 illustrates schematically the fluid transfer structure shown in figure 1 in an operative position where the outer platform unit is attached to the hull of a floating unit (a ship) and the at least one cargo pipe of the fluid transfer structure is fluidly connected to a manifold on the floating unit.

Figure 3 illustrates schematically a top view of a second embodiment of a fluid transfer structure according to the present invention arranged in an idle position, where the fluid transfer structure comprises two bridge sections that are rotatably attached to an intermediate platform unit.

Figure 4 illustrates schematically a top view of the second embodiment of the fluid transfer structure shown in figure 3 in an operative position where the outer platform unit is attached to the hull of a floating unit (a ship) and the at least one cargo pipe of the fluid transfer structure is fluidly connected to a manifold on the floating unit.

Figure 5 illustrates schematically a section through a bridge section of the fluid transfer structure where the bridge section includes a gangway with rails and a pipe rack for the at least one cargo pipe and other tubular elements.

Figure 6 illustrates schematically a top view of an intermediate platform unit and a bridge section rotatably connected to the intermediate platform unit. Figure 7 illustrates schematically an intermediate platform arranged in an idle position supported towards piles.

Figure 8 illustrates schematically a possible pipe system to be arranged on the outer platform to which the at least one cargo pipe and the at least one aerial conduit are fluidly connected.

Figure 9a-9b illustrates schematically a compensation system arranged on the bridge section for compensation of relative movements between the bridge section and the non-floating or floating facility due to tidal range, water waves etc., where the compensation system is mounted on the bridge section. Figure 10 illustrates schematically a fluid transfer structure in an operative position where the fluid transfer structure comprises three bridge sections interconnected by two intermediate platform units and an outer platform unit that is releasably attached to the hull of an LNG carrier and aerial hoses are connected to the manifold of the LNG carrier for transfer of LNG to or from a non-floating or floating facility.

Figure 11 illustrates schematically illustrates the same fluid transfer structure as in figure 8 seen from a different angle.

Figure 12 illustrates schematically an intermediate platform unit supported by a buoyancy element and two bridge sections that are rotatably connected to the intermediate platform unit.

Figure 13 illustrates schematically shows a fluid transfer structure for bunkering of a vessel where the fluid transfer structure is arranged in an idle position.

Figure 14 illustrates schematically the fluid transfer structure shown in figure 12 in an operative position where the fluid transfer structure is used for bunkering of the vessel, for example a ferry.

Firstly, it should be noted that in the figures the same features have the same reference number in all figures. It should also be noted that not all features of the various embodiments are included on all figures.

In figures 1 and 2 there is shown an embodiment of the present fluid transfer structure 10 which will work best in quiet waters, such as harbours, where there is small or negligible water waves and little or no currents in the water. The fluid transfer structure 10 comprises a bridge section 20 that is connected to a support platform 80, preferably with a joint device 81 that allows the bridge section 20 to rotate about three independent axes passing through the joint device 81. The joint device 81 is preferably further designed to allow the bridge section 20 to move in a horizontal plane relative to the support platform 80. The joint device 81 may, for example, include a ball joint. Furthermore, the bridge section 20 of the embodiment shown in figures 1 and 2 is preferably designed such that some torsional movement around its longitudinal axis is allowed.

The support platform 80 may be a floating support structure 80 as shown in 8a-8b and described in more detail below, i.e. the support platform 80 may be provided with a tidal compensation device to compensate for varying levels of the water surface due the tide. Tidal differences can vary substantially from one place to another, so whether or not to include a tidal compensation device on the support platform 80 must be considered from case to case. A tidal compensation device is shown in figures 8a-8b and will further described below.

The support platform 80 and the pilings 122 are arranged adjacent a pier structure 116 which extends from a quay 115. The support platform 80 is preferably attached to the pilings 122 such that it can move vertically in response to varying level of the surface of the body water 136, for example due to varying tidal levels. The embodiment of the fluid transfer structure 10 shown in figures 1 and 2 may therefore be designed without the tidal compensation device shown in figures 8a-8b.

From the pier structure 116 and over to the support platform 80 there may be arranged a ramp unit 119 that is capable of adjusting to relative vertical motion between the pier structure 116 and the support platform 80, for example by mounting one end portion of the ramp unit 119 rotatably to the pier structure 116 and arranging the other end slidingly or rollably on the deck of the support platform 80. It should be mentioned that in places where there is no or little variation in the vertical level of the water surface, for example due to small or no tidal differences, the bridge section 20 may be rotatably attached directly to a pier structure 116 or a quay 115 or any other suitable structure.

The fluid transfer structure 10 shown in figures 1-2 further comprises an outer platform unit 42 which is arranged at the end of bridge section 20, or bridge sections 20 if the fluid transfer structure 10 is provided with two or more bridge sections. The bridge section 20 can be rotatably attached to the outer platform unit 42, preferably with a joint device 48 which allows the bridge section 20 to rotate about three independent axes passing through the joint device 48. The joint device 48 may, for example, be a ball joint. An alternative solution would be to integrate the outer platform unit 42 and the bridge section 20 into a single unit. Such a solution is indicated in figures 13 and 14.

The fluid transfer structure 10 comprises at least one cargo pipe 12 through which a fluid can be transported from the non-floating or floating facility 114 (as shown in figure 10) to the floating unit 110 or vice versa as indicated in the figures. The at least one cargo pipe 12 is mounted on the at least one bridge section 20, the outer platform 42 and possibly one or more intermediate platform units 60 and a corresponding number of additional bridge section or bridge sections 20, and/or a support platform 80 as shown in the various figures. The at least one bridge section 20 of the fluid transfer structure 10 comprises a support structure 21 (as shown in figure 5) and at least one cargo pipe section 32. The at least one cargo pipe section 32 is securely mounted on the support structure 21 such that the at least one cargo pipe section 32 is located above the surface of the body of water 136. As shown in figure 5, the bridge section 20 may further be provided with a tubular support unit 27 which is securely attached to the support structure 21 and preferably extends along the length of the bridge section 20. The tubular support unit 27 may comprise a number of shelves on which various types of tubular elements 17, such as utilities pipes and control cables, in addition to the at least one cargo pipe section 32, are mounted. The bridge section 20 is further provided with a walkway 29 and hand rails 30 for personnel, which is arranged beside the tubular support unit 27 such that the tubular elements arranged in the tubular support unit 27 can easily be inspected and maintenance and repair can easily be performed.

The outer platform unit 42 comprises a deck 44 and at least one attachment unit 50 that is securely attached to the deck 44. The attachment unit 44 comprises at least one attachment element 51 that is adapted to be releasably attached to the floating unit 110, for example to an outer surface of the hull of the floating unit 110. The at least one attachment element 51 may for example comprise one or more vacuum pads or one or more electromagnetic pads or a mix of one or more vacuum pads and one or more electromagnetic pads.

Alternatively, the attachment unit may comprise one or more mooring lines (not shown in the figures) that are securely attached to the outer platform unit 42 of the fluid transfer structure 10 and can be releasably attached to the floating unit 110. A combination of vacuum pads and/or electromagnetic pads and one or more mooring lines may of course also be used.

To prevent direct impacts between the outer platform unit 42 and the floating unit 110 and to dampen impacts between the outer platform unit 42 and the floating unit 110 that may take place during the process of manoeuvring the outer platform unit 42 towards the floating unit 110 and thereby avoid damages to the fluid transfer structure 10 and equipment arranged on the fluid transfer structure 10, and also to the floating unit 110, the outer platform unit 42 is preferably provided with at least one, but preferably two or more fenders 45. For example, one or more fenders 45 can be securely mounted to the outer platform unit 42 on either side of an attachment unit 50 as indicated in figures 1-4 and 10-11. The fenders 45 can be designed in a way that as is well known in the art and will not be further described herein.

The outer platform unit 42 further preferably comprises at least one buoyancy element 57 (as shown in figure 14) that provides buoyancy to the fluid transfer structure 10. The bridge section 20 is normally not provided with buoyancy elements and is therefore supported by the outer platform unit 42 and the support platform 80 or the pier 116 or quay 115 if there is little or no tidal variation such that the bridge section 20 is connected directly to the pier or the quay.

Alternatively, the bridge section may of course be provided with one or more buoyancy elements to contribute to the total buoyancy of the fluid transfer structure 10

The outer platform unit 42 is further provided with a pipe system 87. The pipe system 87 may be a single pipe element that is connected to the cargo pipe section 32 on the bridge section 20 with a pipe connection 56. The pipe element on the outer platform unit 20 is further connected to a valve device 89 to which an aerial conduit 53 (as shown in figure 2) can be connected during fluid transfer operations. Preferably the aerial conduit 53 is permanently connected to the pipe system 87 and stored on the outer platform 42 between fluid transfer operations.

In figure 1 the fluid transfer structure 10 is shown in an idle or storage position, while in figure 2 it is shown in an operational position where the attachment element 51 of the attachment unit 50 on the outer platform unit 42 is attached to the hull of the floating unit 110. The aerial conduit 53 is connected to the manifold of the floating unit 110 and a fluid transfer operation may take place.

In figures 3 and 4, a similar fluid transfer structure 10 as in figures 1-2 is shown, but instead of being provided with a single bridge section 20 the fluid transfer structure 10 shown in figures 3 and 4 comprises two bridge sections 20 where each of the two bridge sections are connected to an intermediate platform unit 60. The innermost bridge section 20 may be connected to a support platform 80 as described above which is connected to the pilings 122 such that it can move vertically in response to varying level of the surface of the body water 136, for example due to varying tidal levels. As mentioned, a tidal compensation device is shown in figures 9a-9b and will further described below.

In the same way as for the embodiment shown in figures 1-2, the support platform 80 and the pilings 122 are arranged adjacent a pier structure 116 which extends from a quay 115. From the pier structure 116 and over to the support platform 80 there may be arranged a ramp unit 119 that is capable of adjusting to relative vertical motion between the pier structure 116 and the support platform 80, for example by mounting one end portion of the ramp unit 119 rotatably to the pier structure 116 and arranging the other end slidingly or rollably on the deck of the support platform 80. It should be mentioned that in places where there is no or little variation in the vertical level of the water surface, for example due to small or no tidal differences, the innermost bridge section 20 may be rotatably attached directly to the pier structure 116 or the quay 115 or any other suitable structure.

The fluid transfer structure 10 shown in figures 3 and 4 further comprises an outer platform unit 42 which is arranged at the end of the outermost of the two bridge sections 20. The bridge section 20 can be rotatably attached to the outer platform unit 42, preferably with a joint device 48 which allows the bridge section 20 to rotate about three independent axes passing through the joint device 48. The joint device 48 may, for example, be a ball joint. An alternative solution would be to integrate the outer platform unit 42 and the bridge section 20 into a single unit.

Such a solution is indicated in figures 13 and 14.

The fluid transfer structure 10 comprises at least one cargo pipe 12 through which a fluid can be transported from the non-floating or floating facility 114 (as shown in figure 10) to the floating unit 110 or vice versa. The at least one cargo pipe 12 is mounted on the two bridge sections 20, the outer platform 42 and the intermediate platform unit 60 the support platform 80 as shown in the figure.

Each bridge section 20 of the fluid transfer structure 10 comprises a support structure 21 (as shown in figure 5) and at least one cargo pipe section 32. The at least one cargo pipe section 32 is securely mounted on the support structure 21 such that the at least one cargo pipe section 32 is located above the surface of the body of water 136.

As shown in figure 5, the bridge section 20 may further be provided with a tubular support unit 27 which is securely attached to the support structure 21 and preferably extends along the length of the bridge section 20. The tubular support unit 27 may comprise a number of shelves on which various types of tubular elements 17, such as utilities pipes and control cables, in addition to the at least one cargo pipe section 32, are mounted. The bridge section 20 is further provided with a walkway 29 and hand rails 30 for personnel, which is arranged beside the tubular support unit 27 such that the tubular elements arranged in the tubular support unit 27 can easily be inspected and such that maintenance and repair can easily be performed.

The outer platform unit 42 comprises a deck 44 and at least one attachment unit 50 that is securely attached to the deck 44. The attachment unit 44 comprises at least one attachment element 51 (as shown in figures 1-2) that is adapted to be releasably attached to the floating unit 110, for example to the outer surface of the hull of the floating unit 110. The at least one attachment element 51 may for example comprise one or more vacuum pads or one or more electromagnetic pads or a mix of one or more vacuum pads and one or more electromagnetic pads.

Alternatively, the attachment unit may comprise one or more mooring lines (not shown in the figures) that are securely attached to the outer platform unit 42 of the fluid transfer structure 10 and can be releasably attached to the floating unit 110. A combination of vacuum pads and/or electromagnetic pads and one or more mooring lines may of course also be used.

To prevent direct impacts between the outer platform unit 42 and the floating unit 110 and to dampen impacts between the outer platform unit 42 and the floating unit 110 that may take place during the process of attaching the outer platform unit 42 to the floating unit 110 and thereby avoid damages to the fluid transfer structure 10 and equipment arranged on the fluid transfer structure 10, and also to the floating unit 110, the outer platform unit 42 is preferably provided with at least one, but preferably two or more fenders 45. For example, one or more fenders 45 can be securely mounted to the outer platform unit 42 on either side of an attachment unit 50 as indicated in figures 1-4 and 10-11. The fenders 45 can further be provided with respective pads 25 to further soften impacts. Otherwise, the fenders can be designed in a way that as is well known in the art and will not be further described herein.

The outer platform unit 42 further preferably comprises at least one buoyancy element 57 (as shown in figure 14) that provides buoyancy to the fluid transfer structure 10. The bridge sections 20 are normally not provided with buoyancy elements and is therefore supported by the outer platform unit 42, the intermediate platform unit 60 and the support platform 80 or the pier 116 or quay 115 if there is little or no tidal variation such that the innermost bridge section 20 is connected directly to the pier or the quay. Alternatively, the bridge section may of course be provided with one or more buoyancy elements to contribute to the total buoyancy of the fluid transfer structure 10.

Alternatively, the at least one bridge section 20 may be provided with one or more buoyancy elements that may provide all or some of the necessary buoyancy to the fluid transfer structure 10, i.e. the at least one bridge section 20 may be provided with buoyancy in addition to the outer platform unit 42 and/or any intermediate platform unit 60 or the at least one bridge section may be provided with all the buoyancy of the fluid transfer structure.

For example, two adjacent bridge sections 20 may be interconnected directly without using an intermediate platform unit and the two adjacent bridge sections 20 are preferably provided with one or more buoyancy elements all or some of the required buoyancy to the fluid transfer structure 10. The two bridge sections 20 may be connected to each other with one or more joint devices allowing relative rotation between the two bridge sections 20 about two or more independent axes. For example, the two bridge sections 20 may be allowed to rotate about a substantially vertical axis and about an axis which is substantially horizontal and perpendicular to the longitudinal direction of one of the two bridge sections 20.

The outer platform unit 42 is further provided with a pipe system 87, for example like the one shown in figures 1-2 or a more complicated pipe system as shown in figure 8. The pipe system 87 may be a single pipe element that is connected to the cargo pipe section 32 on the outermost bridge section 20 with a pipe connection 56. Referring to the pipe system 87 shown in figures 1-2, the pipe element on the outer platform unit 20 can further be connected to a valve device 89 to which an aerial conduit 53 (as shown in figure 2) can be connected during fluid transfer operations. Preferably the aerial conduit 53 is permanently connected to the pipe system 87, via valve 89, and stored on the outer platform 42 between fluid transfer operations.

The fluid transfer structure shown in figures 3 and 4 further comprises an intermediate platform unit 60 to which the support structures 21 of the two bridge sections 20 are connected with respective joint devices 68 and 69. A more detailed version of the intermediate platform unit is shown in figures 6 and 7.

The intermediate platform unit 60 comprises a deck 61. The two bridge sections 20 can be rotatably connected to the intermediate platform unit with respective joint devices 68 and 69 which allows the bridge sections 20 to rotate about three independent axes. The joint devices 68, 69 may be a ball joint or any other suitable joint device that allows relative rotation about three different axes.

Alternatively, at least one bridge section 20 may be attached to the intermediate platform unit 60 with the first joint device 68 or the second joint 69 that allows the at least one bridge section 20 to rotate in less than three degrees of freedom relative to the intermediate platform unit 60.

For example, if the at least one bridge section 20 is designed with inherent flexibility that allows the at least one bridge section 20 to twist about an axis in its longitudinal direction and/or to bend about a horizontal axis that is substantially perpendicular to the bridge section’s longitudinal direction and/or to bend about a substantially vertical axis, a first or a second joint device 68, 69 may be provided that allows the at least one bridge element 20 to rotate in two, one or none degrees of freedom relative to the intermediate platform unit 60.

Similarly, the at least one bridge section 20 may be attached to the outer platform unit 42 with a joint device 48 that allows the at least one bridge section 20 to rotate in less than three degrees of freedom relative to the outer platform unit 42.

For example, if the at least one bridge section 20 is designed with inherent flexibility that allows the at least one bridge section 20 to twist about an axis in its longitudinal direction and/or to bend about a horizontal axis that is substantially perpendicular to the bridge section’s longitudinal direction and/or to bend about a substantially vertical axis, a joint device 48 may be provided that allows the at least one bridge element 20 to rotate in two, one or none degrees of freedom relative to the outer platform unit 42.

In the same way, the at least one bridge section 20 may also be attached to a support platform 80, or to a pier structure 116, with a joint device 81 that allows the at least one bridge section 20 to rotate in less than three degrees of freedom relative to the support platform 80 or the pier structure 116. For example, if the at least one bridge section 20 is designed with inherent flexibility that allows the at least one bridge section 20 to twist about an axis in its longitudinal direction and/or to bend about a horizontal axis that is substantially perpendicular to the bridge section’s longitudinal direction and/or to bend about a substantially vertical axis, a joint device 81 may be provided that allows the at least one bridge element 20 to rotate in two, one or none degrees of freedom relative to the support platform 60 or the pier structure 116.

There is further provided one or more roller device(s) 24, which can be mounted on the bridge sections or on the deck 61 of the intermediate platform unit 60, such that when the bridge sections 20 rotates in a horizontal plane relative to the intermediate platform unit 61, the bridge sections 20 roll over the deck 61. In figure 7, the intermediate platform unit 60 is shown with roller supports 67 for support of roller devices 24 that are mounted on the support structures 21 of the two bridge sections 20. Alternatively, the bridge elements may be sliding on top of the intermediate platform 60 in the same configuration.

The intermediate platform unit 60 is further provided with a connecting cargo pipe section 64. The connecting cargo pipe section 64 is preferably flexible, i.e. it is bendable to a desired degree. The connecting cargo pipe section 64 is connected to cargo pipe sections 32 arranged on the two bridge sections 20 with respective pipe connections 65, 66. The pipe connections 65, 66 may for example be conventional flange connections or any other suitable pipe connection. The intermediate platform unit 60 may also be provided with a support member 70 for support of the connecting cargo pipe section 64 as indicated in figure 6. The intermediate platform unit 60 may further be provided with a propulsion unit or thruster unit (not shown in the figures) which is used to move the fluid transfer structure 10 between the storage position and the operational position. In figure 7, the intermediate platform unit is further shown with piling brackets 72 arranged such that a piling 122 fits in between the two piling brackets when the fluid transfer structure 10 is in the storage position. The intermediate platform unit 60 can further be provided with bollards 63 for mooring of the intermediate platform unit to, for example, the pilings 122 when the fluid transfer structure 10 is in the storage position. Alternatively, the transfer structure 10 may be moored with ropes to the quay or seabed either during operation or in

The fluid transfer structure 10 may further comprise a rotational control mechanism (not shown in the figures) which compels the support structures 21 of the two bridge sections 20 that are connected to the intermediate platform unit 60, and consequently the two bridge sections 20 themselves, to follow equal angular movements in opposite clockwise directions in a horizontal plane relative to the at least one intermediate platform unit 60. Such a rotational control mechanism is included to avoid S-shaped bending of the flexible connecting cargo pipe section 64 when the bridge sections 20 rotate relative to the at least one intermediate platform unit 60. The rotational control mechanism may, for example, comprise a hydraulic actuation assembly, i.e. a conventional piston/cylinder assembly, or a system of cogwheels interconnecting the two support sections 21 and the intermediate platform unit 60 and causing the support structures 21 to follow equal angular movements in opposite clockwise directions in a horizontal plane relative to the at least one intermediate platform unit 60.

Furthermore, the two bridge sections 20 are preferably connected to the at least one intermediate platform unit 60 with their respective joint devices 65, 66 such that the distance between respective end portions of the at least one cargo pipe section 32 on each of the two bridge sections 20 is substantially constant when the two bridge sections, and thereby the at least one cargo pipe section on each of the two bridge sections, are rotated horizontally relative to the intermediate platform unit 60.

In figure 3 the fluid transfer structure 10 is shown in an idle or storage position, while in figure 4 it is shown in an operational position where the attachment element 51 of the attachment unit 50 on the outer platform unit 42 is attached to the hull of the floating unit 110. One or more aerial conduits 53, as indicated in figure 2, will be connected to the manifold of the floating unit 110 and the pipe system 87 on the outer platform unit 42, and a fluid transfer operation may take place.

In figures 9a and 9b the support platform 80 which can be used to compensate for variations in the level of the surface 137 of the body of water, due to for example tidal motion as mentioned above.

On the support platform 80 there is mounted a tidal compensation system 78 which comprises a tubular support unit 84 which is securely mounted on the support platform 80. The tubular support unit 84 comprises a cargo pipe section 128 which is substantially rigid. On the quay 115 there is mounted a pipe rack 131 supported by a bracket 85. On the pipe rack 131 at least one pipe element 118 is arranged which is fluidly connected to the non-floating or floating facility 114. A flexible connecting cargo pipe section 82 is in one end connected to the at least one pipe element 118 with a pipe connection 83 of a suitable type and in the other end to the cargo pipe section 128 with a suitable pipe connection 130. The flexible connecting cargo pipe section 82 is provided with a substantially J-shape or U-shape and thereby allows a substantial relative vertical movement between the quay 131 and the support platform 80. The tubular support unit 84 may further be provided with a desired number similar arrangement for further tubular elements, such as the additional cargo pipes, utilities pipes and control cables as mentioned above. The use of the support platform 80 with the tidal compensation system 78 described above may be omitted if that is desired, for example if there is a relatively little difference between the vertical position of the water surface at high tide and at low tide. The at least one bridge element 20, or the innermost bridge element 20 if the fluid transfer structure 10 is provided with two or more bridge elements 20, may be attached to the pier structure 116 with a joint device 81 in the same way as to the support platform 80. The joint device 81 preferably allows the bridge section 20 to rotate about three independent axes passing through the joint device 81. The joint device 81 may, for example, be a ball joint. In addition, a ramp unit 119 as indicated in figures 13 and 14 may be provided which extends from the top of the pier structure 116 down to the at least one bridge section 20. The ramp unit may be pivotably attached to the pier structure 116 and slidingly arranged on the at least one bridge section 20 such that the ramp unit 119 can slide along the top surface of the at least one bridge section 20 when the at least one bridge section 20 moves due to wave motions or tidal movements. A connecting cargo pipe section 120 may further be provided connecting the at least one pipe element 118 on the pier structure 116 to the at least one cargo pipe 12. The connecting cargo pipe section 120 may be a flexible pipe element to compensate for relative movements between the at least one bridge structure 20 and the pier structure 116.

In figure 8 there is shown a schematic figure of a possible pipe system 87 that can be arranged on the outer platform unit 42. The pipe system 87 shown is particularly suitable for transfer of LNG where two cargo pipes are used. The pipe system comprises a first cargo pipe 14, which is connected to the first cargo pipe element 90 of the pipe system 87, and a second cargo pipe 15, which is connected to the second cargo pipe element 91 of the pipe system 87. In the other ends of the first cargo pipe element 90 and the second cargo pipe element 91, they are connected to first aerial conduit 54 and a second aerial conduit 55 respectively.

In the first cargo pipe element 90 there may be provided several valve devices, such as an emergency shut down valve device (ESD) 97, a cargo valve device 98 and a break away coupling 99 as indicated in figure 8. Similarly, in the second cargo pipe element 91 there may also be provided several valve devices, such as an emergency shut down valve device (ESD) 97, a cargo valve device 98 and break away coupling 99 as indicated in figure 8.

Between the first cargo pipe element 90 and the second cargo pipe element 91 there is preferably provided a first cross pipe 92 which is fluidly connected to the first cargo pipe element 90 and the second cargo pipe element 91. There may also be provided a second cross pipe 93 between the first cargo pipe element 90 and the second cargo pipe element 91 which is fluidly connected to the first cargo pipe element 90 and the second cargo pipe element 91 as indicated in figure 8. In the first cross pipe 92 and in the second cross pipe 93 there is preferably provided first valve device 95 and a second valve device 96 respectively. With this pipe system 87 the first cargo pipe 14 and the second cargo pipe 15 and the first aerial conduit 54 and the second aerial conduit 55 may be selectively pre-cooled before the transfer of LNG.

The pipe system 87 may be provided with further features such as vent pipe system 101 that is capable of venting trapped gas in the pipe system 87. As indicated on figure 8, the vent pipe system may comprise a first vent pipe 102 connected to the second cargo pipe element 91 on one side of the cargo valve device 98 and a second vent pipe 103 connected to the first cargo pipe element 90 on one side of the cargo valve device 98, a third vent pipe 104 connected to the second cargo pipe element 91 on the opposite side of the cargo valve device 98 and a fourth vent pipe 105 connected to the first cargo pipe element 90 on the opposite side of the cargo valve device 98. All four vent pipes 102, 103, 104, 105 are fluidly connected to the vent mast 107 such that any trapped gas can be vented through the vent mast in case of emergency shutdown.

In figures 10-12 there is shown a fluid transfer structure 10 comprising two cargo pipes 14, 15 as described above in connection with figure 8. The fluid transfer structure comprises three bridge sections, a first bridge section 38, a second bridge section 39 and a third bridge section 40. The fluid transfer structure 10 further comprises two intermediate platform units, a first intermediate platform unit 74, which is connected to the first bridge section 38 and to the second bridge section 39, and a second intermediate platform unit 75, which is connected to the second bridge section 39 and to the third bridge section 40. The third bridge section 40 is connected to the outer platform unit 42 as described above. As shown in figure 12, the intermediate platform units 74, 75 are provided with a buoyancy element 71. In addition, the outer platform unit 42 is preferably also provided with one or more buoyancy elements. The three bridge elements 38, 39, 40 are, in this embodiment of the fluid transfer structure 10, not provided with any buoyancy elements and are supported by the outer platform unit 42, the intermediate platform units 74, 75 and the pier 116 or support platform 80.

The outer platform unit 42 is attached to the floating unit 110 with two attachment units 50. The outer platform unit is provided with a pipe system 87, for example a pipe system like the one shown in figure 8, which is connected to the two cargo pipes 14, 15 and to two aerial pipes 54, 55. The two aerial pipes 54, 55 are further connected to the manifold of the floating unit 110 whereby fluid can be transferred between the floating unit 110 and the non-floating or floating facility 114.

In figures 13 and 14 a slightly different version of the fluid transfer structure is shown which is particularly useful for bunkering of fuel, such as LNG, for a vessel such as a ferry or a cruise ship. The fluid transfer structure 10 is provided with two bridge sections, a first bridge section 38 and a second bridge section 39, and one intermediate platform unit 60 to which the first bridge section 38 and the second bridge sections 39 are connected. The fluid transfer structure 10 is provided with two cargo pipes, a first cargo pipe 14 and a second cargo pipe 15 which are connected to a non-floating or floating facility 114, in this case comprising storage tanks, with the pipe elements 118 as mentioned above. In this embodiment of the fluid transfer structure 10, the outer platform unit 42, as shown in figures 13 and 14, is formed as an integral part of the second bridge section 39 and the pipe system 87 on the outer platform unit 42 is simpler than the pipe system shown in figures 8 and 10 12

The fluid transfer structure 10 is shown in its idle or storage position in figure 13 while the floating unit 110 is moored to the quay 115. By rotating the first bridge element 90 degrees relative to the quay 115 as compared to the storage position of the fluid transfer structure 10 and by rotating the first bridge section 39 and the second bridge section 45 degrees relative to the intermediate platform unit 60 respectively, the outer platform unit 42 will be located on the opposite side of the floating unit 110 as compared to the quay 115 and next to the manifold of the floating unit 110 to which the aerial conduits are connected for bunkering of fuel. The invention has now been explained with reference to a non-limiting example. A person skilled in the art will, however, appreciate that modifications and changes may be made to this embodiment which will be within the scope of the invention as defined in the following claims.