GB2606417A

GB2606417A - Apparatus for transfer of personnel goods and/or equipment

Info

Publication number: GB2606417A
Application number: GB2111580.3A
Authority: GB
Inventors: Glover James
Original assignee: Maritime Systems Ltd
Current assignee: Maritime Systems Ltd
Priority date: 2021-05-05
Filing date: 2021-08-12
Publication date: 2022-11-09
Also published as: GB202111580D0; GB202106434D0

Abstract

An apparatus 200 for transfer of personnel, goods and/or equipment from a water-borne vessel (204, Fig 7) to a relatively immobile structure (208, Fig 7) comprises a platform 215 accessible from the water-borne vessel, one or more fenders 221 and 222 at least partially disposed forward of the platform and arrangable to be brought into contact, in use, with the relatively immobile structure. The apparatus has a braced configuration, in which the platform is held in a fixed position relative to the water-borne vessel and a non-braced configuration, in which the platform can move in at least a substantially vertical direction relative to the water-borne vessel. The apparatus further comprises a control system configured to allow user selection of the braced configuration and the non-braced configuration. A system (1000, Fig 16) for assisting a skipper of a water-borne locate a target portion of a relatively immobile structure using a lidar camera (1001, Fig 16) and a visual camera (1002, Fig 16) is also disclosed. Methods for using the apparatus and the system are also disclosed.

Description

APPARATUS FOR TRANSFER OF PERSONNEL, GOODS AND/OR EQUIPMENT The present disclosure relates to an apparatus for transfer of personnel, goods and/or equipment, more particularly to an apparatus for transfer of personnel, goods and/or equipment from a water-borne vessel to a relatively immobile structure.

Offshore wind farms comprising large numbers of wind turbines are seen as a key part of the UK's energy supply infrastructure, as the UK tries to decarbonise its economy.

Such offshore wind farms can be built long distances from the shore in open seas.

During construction and for maintenance during their service lifetime, personnel often need to access offshore wind turbines. Boats known as crew transfer vessels are used to carry personnel to and from offshore wind turbines. Sea conditions are inherently variable and can make it challenging to transfer personnel from a crew transfer vessel to an offshore wind turbine in a safe and secure manner.

Offshore wind turbines typically have an access ladder attached to a side of a tower and two vertical bumper tubes spaced either side of the ladder.

Personnel are ferried to the offshore wind turbines in crew transfer vessels. On arrival, the bow of the crew transfer vessel is driven against the bumper tubes to try to keep the bow stable xyhile personnel transfer to or from the offshore wind turbine.

Waves, ocean swell, and wind can cause the vessel to move relative to the offshore wind turbine making this a dangerous event that needs to be managed carefully. Regulations stipulate that the disembarkation platform must be stationary before a worker can step across onto the access ladder.

To achieve this, the bow of the crew transfer vessel is driven hard against the bumper tubes to create enough friction to hold the bow steady. This can result in the bow lifting out of the water or being held under the water as the water swells around the vessel With the bow of the vessel out of the water, the risk is that the unsupported mass in the air becomes too high, and the friction force is no longer enough to hold it up, resulting in a sudden drop.

If the bow is held against the structure whilst the water rises, the increased volume in the water creates increased buoyancy, which can suddenly overcome the friction force and the bow can rise suddenly and rapidly.

Both outcomes can be very dangerous for someone mid-transfer or personnel anywhere in the vessel The sudden motion can be violent and throw them around, or even overboard.

If the wave height is more than 1.5 metres, dependent upon vessel, then the risk of the vessel breaking away is considered too high and industry safety regulations prohibit the transfer of personnel in such conditions. If the situation does not improve, then work for the day is abandoned and the crew transfer vessel returns to base.

The consequent loss of working days hampers construction and maintenance schedules and consequently leads to an increase in building and operating costs. For a typical crew transfer vessel transporting 12 workers, the direct financial cost is £.10,000 per abandoned day, plus added costs if the project is behind schedule and forced to incur overtime costs to catch up.

There is also concern about potential structural damage to the offshore wind turbine from the vessel's being driven hard against the bumper tubes, particularly in large swells. There is also potential for the foundations of the offshore wind turbine to become damages as a result of crew transfer vessels repeatedly being driven hard against the bumper tubes to maintain a stable transfer platform.

While various technical solutions have been developed, in the UK offshore wind industry the predominant way to transfer personnel from a crew transfer vessel to an offshore wind turbine is still to drive the bow of the crew transfer vessel hard against the offshore wind turbine structure.

It would be beneficial to mitigate or alleviate one or more of the aforementioned problems.

A first aspect provides an apparatus for transfer of personnel, goods and/or equipment from a water-borne vessel to a relatively immobile structure comprising: a platform accessible from the water-borne vessel; one or more fenders at least partially disposed forward of the platform and arrangable to be brought into contact, in use, with the relatively immobile structure; wherein the apparatus has a braced configuration, in which the platform is held in a fixed position relative to the water-borne vessel; and the apparatus has a non-braced configuration, in which the platform can move in at least a substantially vertical direction relative to the water-borne vessel; and the apparatus comprises a control system configured to allow user selection of the braced configuration and the non-braced configuration; IS wherein, in use, thrust of the water-borne vessel pushes the fender(s) against the relatively immobile structure to maintain a stable engagement between the apparatus and the relatively immobile structure so that when the stable engagement is being maintained and the apparatus is in the non-braced configuration the platform remains relatively stationary relative to movement of the water-borne vessel.

By the platform remaining relatively stationary relative to movement of the waterborne vessel, safe and secure transfer of personnel, goods and/or equipment from the platform to the relatively immobile structure and vice versa may be facilitated.

In the non-braced configuration, the platform may be able to move in one or more further directions relative to the water-borne vessel.

Friction between the fender and the relatively immobile structure may maintain the stable engagement.

The apparatus may comprise two or more fenders. One or more of the fenders may be arrangable to contact, in use, a bumper tube on the relatively immobile structure.

One or more of the fenders may comprise a rubber or polymeric material. One or more of the fenders may have one or more contact portions which may comprise one or more friction-producing materials.

The fender(s) may each be shaped and dimensioned to cooperate with an external portion of the relatively immobile structure, e.g. a bumper tube. For example, one or more of the fenders may comprise one or more concave portions configured to cooperate with one or more convex portions of the relatively immobile structure.

One or more of the fenders may be deformable at least in part.

One or more of the fenders may comprise any suitable material or combination of materials, which may include for example a plastics material, a polymeric material or a rubber. I5

The fender(s) may be operably connected to one or more biasing members or mechanisms arranged to urge the fender(s) against the relatively immobile structure. The one or more biasing members or mechanisms may include one or more elastically deformable members such as a spring, damper or the like.

One or more of the fenders may comprise one or more rollers or wheels arranged to come into contact, in use, with the relatively immobile structure. The roller(s) or wheel(s) may be mounted within the fender such that a portion of the roller(s) or wheel(s) protrudes from the fender. When the roller(s) or wheel(s) first come into contact with the relatively immobile structure it/they may be able to rotate to allow some movement of the fender along a surface of the relatively immobile structure. As the force pushing the fender(s) against the relatively immobile structure increases, the roller(s) or wheel(s) may be prevented from rotating. For example, the roller(s) or wheel(s) may be pushed into the fender to a position where a brake or other mechanism prevents the roller(s) or wheel(s) from rotating.

One or more of the fenders may be movable between a stowed arrangement and a deployment arrangement, in which the fender(s) is/are at least partially disposed forward of the platform and arranged to be brought into contact, in use, with the relatively immobile structure.

The apparatus may comprise a support frame mountable on a deck of the vessel. The platform may be disposed on the support frame.

The support frame may be configured to be connected in use, to the water-borne vessel, e.g. to a deck of the water-borne vessel.

The apparatus may comprise a gangway. An end of the gangway may be hingedly connected to the platform.

The gangway may have a variable length, i.e. the gangway may be an extendable gangway. For instance, the gangway may comprise two or more telescopically-arranged gangway portions.

A resilient biasing system may be configured to act lengthways (longitudinally) along the extendable gangway.

The apparatus may comprise a first platform and a second platform. The second platform may be the platform, which is held in a fixed position relative to the waterborne vessel when the apparatus is in the braced configuration and which can move in at least a substantially vertical direction relative to the water-borne vessel when the apparatus is in the non-braced configuration.

The or a gangway, e.g. the or an extendable gangway, may extend between the first platform and the second platform.

A first end of the gangway may be hingedlv connected to the first platform and a second end of the gangway may be hingedly connected to the second platform.

The gangway may be rotatable relative to the first platform about an axis passing perpendicularly through the first platform. Rotation of the gangway relative to the first platform may be constrained to a limited arc, e.g. to 2700 of arc or less, 180° of arc or less, 1350 of arc or less, 120° of arc or less or 90° of arc or less.

The first platform may be accessible from the water-borne vessel.

The apparatus may comprise a ramp, a ladder or a staircase arranged to provide access from the water-borne vessel to the platform, e.g. from a deck of the water-borne vessel to the platform. In embodiments comprising a first platform and a second platform, the ramp, the ladder or the staircase may be arranged to provide access from the water-borne vessel to the first platform, e.g from a deck of the water-borne vessel to the first platform The platform, or the second platform, may be mounted on a linkage mechanism. For example, the linkage mechanism may comprise a scissor-lift mechanism. The control system may be arranged to act on the linkage mechanism e.g. the scissor-lift mechanism, to allow user selection of the braced configuration and the non-braced configuration.

A base portion of the linkage mechanism may be pivotably coupled to a stationary portion of the or a support frame or the water-borne vessel such that, in use, the base portion can rock from side to side about a pivot axis extending in a lengthways (longitudinal) direction across the water-borne vessel. Either side of the pivot axis, a damper arrangement may connect the base portion of the linkage mechanism to the stationary portion of the or a support frame or the water-borne vessel. In an implementation, the damper arrangement(s) can be controlled by user operation of the control system to prevent, restrict or allow pivoting of the base portion of the linkage mechanism about the pivot axis. in some implementations, an actuator or motor arrangement(s) can be controlled by user operation of the control system to prevent, restrict or allow pivoting of the base portion of the linkage mechanism about the pivot axis.

The apparatus may be collapsible at least in part. The apparatus may be collapsible at least in part into a collapsed arrangement.

In the collapsed arrangement, one or more parts of the apparatus may be substantially flush with a portion of the deck of the water-borne vessel. For instance, any one or more of the first platform, second platform, gangway, fender(s), support frame, ramp, ladder and/or staircase may be substantially flush with a portion of the deck of the water-borne vessel.

The apparatus may be collapsible such that the linkage mechanism such as the scissor-lift mechanism is disposed below the or a portion of the apparatus that is substantially flush with a portion of the deck of the water-borne vessel. The linkage mechanism may connect to a portion of the water-borne vessel that is disposed below a plane of the deck with which the or a portion of the apparatus is substantially flush with when collapsed.

In the collapsed arrangement, one or more parts of the apparatus may be disposed above or below a surrounding region of the deck of the water-borne vessel. One or more parts of the apparatus may be disposed at least partially, or substantially entirely, within a recessed portion of the deck.

The apparatus may comprise one or more doors, covers or the like connected to the water-borne vessel and configured to at least partially conceal one or more parts of the apparatus when in the collapsed arrangement. The one or more doors, covers or the like connected to the water-borne vessel may be connected to the deck of the waterborne vessel. When in the collapsed arrangement, at least one of the one or more doors, covers or the like may be configured to fold down such that they are substantially flush with an adjacent portion of the deck.

The doors, covers or the like may be connected to the deck of the water-borne vessel via one or more hinges. The doors, covers or the like may be operable to pivot between a substantially vertical orientation and a substantially horizontal orientation. In the vertical orientation the doors, covers or the like may act as a safety barrier and may at least partially surround and/or conceal one or more other parts of the apparatus. For example, in the vertical orientation the doors, covers or the like may at least partially surround the linkage mechanism such as the scissor-lift mechanism.

The control system may comprise one or more hydraulic, pneumatic or electric pistons or rams Advantageously, use of the apparatus may provide one or more benefits, which may include: * safe and secure transfer of personnel (e.g. workers), goods and/or equipment in relatively rough sea conditions, e.g. in swell caused by waves of up to 3 metres in height; * reduced push-on loads on the relatively immobile structure * preventing the water-borne vessel from impacting the relatively immobile structure in large swells; * increasing the overall speed and efficiency of transferring personnel, goods and/or equipment to/from the relatively immobile structure; * being relatively cost-effective and simple to maintain in the offshore working environment.

It will be appreciated that this disclosure may provide a water-borne vessel-mountable or mounted apparatus for transferring personnel, goods or equipment from a waterborne vessel to a relatively immobile structure such as an offshore structure while the water-borne vessel is subjected to waves and/or swell towards the relatively immobile structure. The apparatus may provide a means for controlling the horizontal load between the water-borne vessel and the relatively immobile structure through a platform attached through a mechanical system to the water-borne vessel in such a manner that when the apparatus is in the non-braced configuration the motion of the water-borne vessel does not affect the position of the platform A field of use of the apparatus disclosed herein is the offshore energy industry, where it is a known problem to transfer personnel, goods or equipment from a vessel which moves in consequence of the influence of, among others, the swell, waves, currents and wind relative to a (substantially) stationary destination such as, for example an offshore drill rig, offshore wind turbine or another large vessel.

When using the apparatus disclosed herein, it will be appreciated that instead of the water-borne vessel pushing its bow fender against the bumper tubes on the wind turbine, the apparatus has one or more fenders that are pushed against the bumper tubes.

The platform may be connected to a vertical sliding frame through a spring-loaded mechanism, such that when the platform has been pushed a set distance, the force against the turbine's bumper tubes and friction between the parts will provide sufficient resistive force to hold the platform stationary.

The push-on force only needs to be sufficient to keep the weight of the platform stationary. Even with a safety factor added, this force will be a fraction of that required to keep a vessel stationary through friction when transferring people in the traditional manner.

Using springs to transfer the vessel force to the platform allows for easy indication that the preload is high enough to generate the required friction. They also provide a more constant friction to be maintained as the vessel moves, reducing the chance of a sudden motion if the friction fails.

A second aspect provides a system for assisting a skipper of a water-borne vessel to I5 locate a target portion of a relatively immobile structure when driving the water-borne vessel towards the relatively immobile structure, wherein the system comprises: a lidar camera arranged to capture lidar images of the target portion of the relatively immobile structure; a visual camera arranged to capture visual images of the target portion of the relatively immobile structure; a processor operably connected to the lidar camera and the visual camera; and an image display operably connected to the processor; wherein the processor is arranged to: receive lidar image data from the lidar camera and visual image data from the visual camera; combine the lidar image data and the visual image data to produce combined images comprising the lidar image data and the visual image data; and send the combined images to the image display.

The image display may be a monitor.

The relatively immobile structure may be an offshore wind turbine.

The target portion of the relatively immobile structure may comprise an access ladder with a bumper tube either side of the access ladder.

A third aspect provides a water-borne vessel with an apparatus according to the first aspect mounted thereon and/or a system according to the second aspect installed thereon.

The apparatus may be mounted on a deck of the water-borne vessel.

The water-borne vessel may be a boat.

The water-borne vessel may be a crew transfer vessel.

The water-borne vessel may be of any length. For instance, the water-borne vessel may be up to 100 metres long, up to 80 metres long, up to 60 metres long, up to 50 metres long, up to 40 metres long, up to 30 metres long, up to 20 metres long or up to 15 metres long.

One or more doors, covers or the like may be connected to the deck of water-borne vessel and configured to at least partially conceal one or more parts of the apparatus when the apparatus is in the or a collapsed arrangement. The one or more doors, covers or the like connected to the water-borne vessel may be connected to the deck of the water-borne vessel. When in the collapsed arrangement, at least one of the one or more doors, covers or the like may be configured to fold down such that they are substantially flush with an adjacent portion of the deck.

The doors, covers or the like may be connected to the deck of the water-borne vessel via one or more hinges. The doors, covers or the like may be operable to pivot between a substantially vertical orientation and a substantially horizontal orientation. In the vertical orientation the doors, covers or the like may act as a safety barrier and help at least partially conceal one or more other parts of the apparatus. For example, in the vertical orientation the doors, covers or the like may at least partially surround the linkage mechanism such as the scissor-lift mechanism.

A fourth aspect provides a method of transferring personnel, goods and/or equipment from a water-borne vessel to a relatively immobile structure comprising: driving a water-borne vessel with an apparatus according to the first aspect mounted thereon towards a relatively immobile structure, so as to push the fender(s) against the relatively immobile structure with the apparatus in the braced configuration, wherein thrust of the water-borne vessel establishes and maintains a stable engagement between the apparatus and the relatively immobile structure; and operating the control system to select the non-braced configuration so that while the stable engagement is maintained and the apparatus is in the non-braced configuration the platform remains relatively stationary relative to movement of the water-borne vessel, thereby enabling the transfer of personnel, goods and/or equipment from the water-borne vessel to the relatively immobile structure and/or vice versa.

After the personnel, goods and/or equipment have been transferred from the waterborne vessel to the relatively immobile structure and/or vice versa, the water-borne vessel may be driven away from the relatively immobile structure, thereby ending the stable engagement between the apparatus and the relatively immobile structure.

Before the water-borne vessel is driven away from the relatively immobile structure, the control system may be operated to select the braced configuration.

A fifth aspect provides a method of assisting a skipper of a water-borne vessel in locating a target portion of a relatively immobile structure comprising: driving a water-borne vessel with a system according to the second aspect installed thereon towards the relatively immobile structure; capturing, using the lidar camera, lidar images of the target portion of the relatively immobile structure; capturing, using the visual camera, visual images of the target portion of the relatively immobile structure; receiving, at the processor, lidar image data from the lidar camera and visual image data from the visual camera; combining, in the processor, the lidar image data and the visual image data to produce combined images comprising the lidar image data and the visual image data; and sending the combined images to the image display.

In some embodiments, the fourth and fifth aspects may be carried out in combination.

IS

The skilled person will appreciate that except where mutually exclusive, a feature or parameter described in relation to any one of the above aspects may be applied to any other aspect. Furthermore, except where mutually exclusive, any feature or parameter described herein may be applied to any aspect and/or combined with any other feature or parameter described herein.

Example embodiments will now be described with reference to the accompanying drawings, in which: Figure 1 shows a personnel transfer apparatus extending from a crew transfer vessel to an offshore wind turbine; Figure 2 is another view of the personnel transfer apparatus of Figure I extending from a crew transfer vessel to an offshore wind turbine; Figure 3 is a side view of another personnel transfer apparatus extending from a crew I5 transfer vessel to an offshore wind turbine; Figure 4 is a perspective view of the personnel transfer apparatus of Figure 3 extending from a crew transfer vessel to an offshore wind turbine; Figure 5 is a perspective view of the personnel transfer apparatus of Figure 3 extending from a crew transfer vessel to an offshore wind turbine; Figure 6 is a perspective view of another personnel transfer apparatus; Figure 7 shows the personnel transfer apparatus of Figure 6 mounted on a deck of a boat and extending to an offshore wind turbine; Figure 8 shows a portion of the personnel transfer apparatus of Figure 6 in a collapsed condition for storage between deployments; Figure 9 shows a lower portion of the personnel transfer apparatus of Figure 6; Figure 10 is a perspective view of another personnel transfer apparatus; Figure I I is a perspective view of the personnel transfer apparatus of Figure 10 in between a deployed configuration and a stowed configuration; Figure 12 is a perspective view of a boat with the personnel transfer apparatus of Figure 10 in between a deployed configuration and a stowed configuration; Figure 13 is a perspective view of the boat of Figure 12 with the personnel transfer apparatus in a deployed configuration; Figure 14 is a perspective view of another personnel transfer apparatus; Figure 15 is a perspective view of the personnel transfer apparatus of Figure 14 in a stowed configuration; Figure 16 illustrates a system for assisting a skipper of a crew transfer vessel to locate a target portion of an offshore wind turbine; Figure 17 represents a visual image of a target portion of an offshore wind turbine; Figure 18 represents a lidar (light detection and ranging) image of the target portion of the offshore wind turbine; Figure 19 represents a combined image comprising the visual image of Figure 10 and the lidar image of Figure 15; and Figure 20 is a chart showing significant wave height in seas around the UK against cumulative number of days throughout the year.

Figures 1 and 2 show a first example of a personnel transfer apparatus 1 for facilitating transfer of personnel, goods and/or equipment from a water-borne vessel to a relatively immobile structure. As illustrated, the personnel transfer apparatus 1 provides safe access from a boat 4 to an offshore wind turbine 8. The boat 4 may be a crew transfer vessel.

The offshore wind turbine 8 has a tower 2 fixed to the seabed and extending upwards to a height above the surface of the sea. At a top end of the tower 2, a nacelle (not shown) houses a generator, which is operably connected to a turbine (not shown) comprising a plurality of turbine blades arranged to be driven, in use, by the wind.

On a side of the tower 2, there is an access ladder 3 for maintenance personnel to climb up and down. A first bumper tube 5 is disposed on a first side of, and radially outside of, the access ladder 3. A second bumper tube 6 is disposed on a second side of, and radially outside of, the access ladder 3. The first bumper tube 5 and the second bumper tube 6 are thus disposed either side of, and forward of, the access ladder 3. As noted elsewhere herein, it is known for the bow of a crew transfer vessel to be driven hard against the first bumper tube 5 and the second bumper tube 6 to hold the crew transfer vessel sufficiently steady while personnel transfer from the crew transfer vessel to the offshore wind turbine 8 or vice versa.

The personnel transfer apparatus I comprises a support frame 7 fixed to a deck 9 of the boat 4. A first platform 10 is disposed on top of the support frame 7. A ladder 11 extends from the deck 9 upwards through a central aperture 12 in the first platform 10 to provide access from the deck 9 to the first platform 10 and vice versa.

A safety fence 13 extends around the perimeter of the first platform 10 except for an access gap 14, which permits a user to move from the first platform 10 on to an extendable gangway 15 extending away from the first platform 10.

The safety fence 13 is rotatably mounted on the support frame 7 such that it can rotate about a vertical axis passing through the centre of the first platform 10. A first end 16 of the extendable gangway 15 is attached to the support frame 7 such that the gangway rotates with the safety fence 13, i.e. so that the access gap 14 remains aligned with the first end 16 of the extendable gangway 15.

The first end 16 of the extendable gangway 15 is hingedly attached to the support frame 7 such that the extendable gangway 15 can move relative to the support frame 7 about a first horizontal hinge axis.

A second end 17 of the extendable gangway 15 is hingedly attached to a second platform 18 such that the extendable gangway 15 can move relative to the second platform 18 about a second horizontal hinge axis.

The length of the extendable gangway 15 is variable and comprises two or more portions longitudinally moveable relative to one another, e.g. two or more telescopically arranged portions, and a resilient biasing system (not shown) acting lengthways (longitudinally) along the extendable gangway 15.

A first handrail 19 extends along a first side of the extendable gangway 15 and a second handrail 20 extends along a second side of the extendable gangway 15.

A first platform handrail 21 is disposed on a first side of the second platform 18. A second platform handrail 22 is disposed on a second side of the second platform 18. A first end and a second end of the second platform 18 are open. Accordingly, in use, a person may move from the extendable gangway 15 on to the second platform 18, across the second platform 18 from the first end to the second end and from the second platform 18 on to the access ladder 3 on the tower 2 of the offshore wind turbine 8.

Outboard of the first platform handrail 21, there is a first fender 23. The first fender 23 is disposed forward of the second end of the second platform 18. The first fender 23 is arranged to contact, in use, the first bumper tube 5. The first fender 23 may comprise one or more contact portions, which may comprise one or more friction-producing materials.

Outboard of the second platform handrail 22, there is a second fender 24. The second fender 24 is disposed forward of the second end of the second platform 18. The second fender 24 is arranged to contact, in use, the second bumper tube 6. The second fender 24 may comprise one or more contact portions, which may comprise one or more friction-producing materials.

A control system (not shown), e.g. comprising a hydraulic system, is configured to control operation of the apparatus 1.

The apparatus 1 has a braced configuration, in which: the extendable gangway 15 and the safety fence 13 are held in angular position relative to the support frame 7 and the first platform 10; the extendable gangway 15 is held at a fixed length; the extendable gangway 15 is held in position such that it cannot move relative to the first platform 10 about the first horizontal axis; and the extendable gangway 15 is held in position such that it cannot move relative to the second platform 18 about the second horizontal axis.

The control system is operable to place the apparatus 1 into, and hold the apparatus 1 in, the braced configuration with the second platform 18 held at any height relative to the first platform 10.

The apparatus 1 has a non-braced configuration, in which: the extendable gangway 15 and the safety fence 13 are not held in angular position relative to the support frame 7 and the first platform 10, i.e. the extendable gangway 15 and the safety fence 13 can rotate relative to the support frame 7 and the first platform 10, but not relative to each other; the extendable gangway 15 is not held at a fixed length; the extendable gangway 15 can move relative to the first platform 10 about the first horizontal axis; and the extendable gangway 15 can move relative to the second platform 18 about the second horizontal axis.

The control system is operable by a user to cause the apparatus 1 to switch from the braced configuration to the non-braced configuration and from the non-braced configuration to the braced configuration.

Operation of the apparatus 1 to enable transfer of personnel from the boat 4 to the offshore wind turbine 8 will now be described.

As the boat 4 is driven towards the offshore wind turbine 8, the control system is operated to place the apparatus 1 into the braced configuration with the second platform 18 held at a desired height relative to the first platform 10 and the first fender 23 and the second fender 24 forward of the bow of the boat 4.

The boat 4 is then driven such that the first fender 23 is brought into contact with the first bumper tube 5 and the second fender 24 is brought into contact with the second bumper tube 6. The thrust from the boat 4 pushes the first fender 23 against the first bumper tube 5 and the second fender 24 against the second bumper tube 6.

The control system is then operated to switch the apparatus 1 from the braced configuration to the non-braced configuration. In the non-braced configuration a stable engagement between the apparatus 1 and the offshore wind turbine 8 is maintained by the thrust of the boat 4 towards the offshore wind turbine 8 and friction between the first fender 23 and the first bumper tube 5 and between the second fender 24 and the second bumper tube 6.

When this stable engagement has been established with the apparatus in the non-braced configuration, the apparatus 1 compensates for the motion of the sea and provides a reliable and safe means for the transfer of personnel from the boat to the offshore wind turbine.

Any variation in alignment of the boat 4 is compensated for by rotation of the extendable gangway 15 and the safety fence 13 relative to the support frame 7 and the first platform 10.

Any variation in height of the boat 4 relative to the offshore wind turbine 8, due e.g. to wave motion is compensated for by movement of the extendable gangway 15 relative to the first platform 10 about the first horizontal axis and movement of the extendable gangway 15 relative to the second platform 18 about the second horizontal axis. The length of the extendable gangway 15 varies as required as the extendable gangway 15 moves relative to the first platform 10 about the first horizontal axis and moves relative to the second platform 18 about the second horizontal axis.

Figure 1 shows the apparatus 1 with the second platform 18 at a first height relative to the first platform 10. Figure 2 shows the apparatus 1 with the second platform 18 at a second height relative to the first platform 10. In both Figure 1 and Figure 2, there is a stable engagement between the apparatus I and the offshore wind turbine 8 maintained by the thrust of the boat 4 towards the offshore wind turbine 8 and friction between the first fender 23 and the first bumper tube 5 and between the second fender 24 and the second bumper tube 6. With the apparatus I in the non-braced configuration, the apparatus 1 can compensate for variation in the height of the boat 4 relative to the offshore wind turbine 8, e.g. as illustrated by Figures 1 and 2 The resilient biasing system acts lengthways along the extendable gangway 15 against the thrust of the boat 4, thereby ensuring that the first fender 23 remains pushed against the first bumper tube 5 and the second fender 24 remains pushed against the second bumper tube 6, even if the distance from the boat 4 to the offshore wind turbine 8 varies, e.g. due to sea conditions, Accordingly, it will be appreciated that the apparatus 1 may provide a safe and secure way for personnel to get from the boat 4 to the offshore wind turbine 8 and vice versa that is able to compensate for changes in sea conditions during deployment. Consequently, use of the apparatus I may facilitate the safe transfer of personnel in rougher scas, thereby enabling, for example, maintenance and servicing activities to be carried out on more days per year.

Figures 3, 4 and 5 show another example of a personnel transfer apparatus 100 for facilitating transfer of personnel, goods and/or equipment from a water-borne vessel to a relatively immobile structure. As illustrated, the personnel transfer apparatus 100 provides safe access from a boat 104 to an offshore wind turbine 108. The boat 104 may be a crew transfer vessel.

The offshore wind turbine 108 has a tower 102 fixed to the seabed and extending upwards to a height above the surface of the sea. At a top end of the tower 102, a nacelle (not shown) houses a generator, which is operably connected to a turbine (not shown) comprising a plurality-of turbine blades arranged to be driven, in use, by the wind.

On a side of the tower 102, there is an access ladder 103 for maintenance personnel to climb up and down. A first bumper tube 105 is disposed on a first side of, and radially outside of, the access ladder 103. A second bumper tube 106 is disposed on a second side of, and radially outside of, the access ladder 103. The first bumper tube 105 and the second bumper tube 106 are thus disposed either side of, and forward of, the access ladder 103. As noted elsewhere herein, it is known for the bow of a crew transfer vessel to be driven hard against the first bumper tube 105 and the second bumper tube 106 to hold the crew transfer vessel sufficiently steady while personnel transfer from the crew transfer vessel to the offshore wind turbine 108 or vice versa.

The personnel transfer apparatus 100 is mounted on a forward portion of a deck 109 of the boat 104.

The personnel transfer apparatus 100 comprises a support frame 107 fixed to the deck 109.

A platform 110 with a safety cage 11 la, 11 lb on opposing sides thereof is mounted via a pair of mounting blocks 1 I2a, 112b to a pair of upright dements 1 I3a, 1136 extending vertically either side of the platform 110.

Each mounting block 112a, 112b is connected to a side of the platform 110 outboard of the safety cage II la, 111b. Each mounting block 112a, 112b is mounted on one of the pair of upright elements 113a, 113b extending vertically either side of the platform 110. Each mounting block 112a, 112b comprises a brake (not shown) arranged to engage with the upright clement 113a, 113b on which it is mounted, in order to hold the platform 110 at a desired height. When the brake (not shown) is released the mounting Hock 112a, 112b can move along the upright element 113a, 1136 on which it is mounted. Operation of the brake may be controlled by any suitable control means. In an example implementation, at least one actuator mechanically coupled to the brakes may be accessible to a person stood on the platform 110.

A fender 114a, 114b is connected to each mounting block 112a, 112b by a resiliently-biased connecting mechanism 115a, 115b extending in a forward direction from the respective mounting block 112a, 112b. The fenders 114a, II4b are disposed forward of the platform 110 and the safety cage 11 la, 111b. One of the fenders 114a is arranged to contact, in use, the first bumper tube 105 and the other of the fenders 114b is arranged to contact, in use, the second bumper tube 106. Each fender 114a, 114b may comprise one or more contact portions, which may comprise one or more friction-producing materials.

An access ramp 116 leads from the deck 109 to the platform 110. A first end of the access ramp 116 is hingedly attached to the platform 110 such that the access ramp 116 can move about a first horizontal hinge axis. A second end of the access ramp 116 rests on the deck 109 of the boat 104. In another implementation, the length of the access ramp 116 may be variable and the second end of the access ramp 116 may be hingedly attached to the deck 109 of the boat 104.

The access ramp 116 may be adapted in ally suitable way to facilitate grip. One or more handrails (not shown) may be arranged alongside at least a portion of the access ramp 116.

A control system (not shown), e.g. comprising a hydraulic system is configured to control operation of the apparatus 100.

The apparatus 100 has a braced configuration, in which: the brakes are engaged to hold the platform 110 at a desired height on the upright members 113a, 113b.

The control system is operable to place the apparatus 100 into, and hold the apparatus 100 in, the braced configuration with the platform 110 held at any height relative to the deck 109 of the boat 104.

The apparatus 100 has a non-braced configuration, in which: the brakes are released and the platform 110 can move relatively freely up and down along the upright members 113a, 113b.

The control system is operable by a user to cause the apparatus 100 to switch from the braced configuration to the non-braced configuration and from the non-braced configuration to the braced configuration.

Operation of the apparatus 100 to enable transfer of personnel from the boat 104 to the offshore wind turbine 108 will now be described.

As the boat 104 is driven towards the offshore wind turbine 108, the control system is operated to place the apparatus 100 into the braced configuration with the platform 110 held at a desired height relative to deck 109 and the fenders 114a, 114b forward of the bow of the boat 104.

The boat 104 is then driven such that one of the fenders 114a is brought into contact with the first bumper tube 105 and the other of the fenders 114b is brought into contact with the second bumper tube 106. The thrust from the boat 104 pushes the one fender 114a against the first bumper tube 105 and the other fender 114b against the second bumper tube 106.

The control system is then operated to switch the apparatus 100 from the braced configuration to the non-braced configuration. In the non-braced configuration, a stable engagement between the apparatus 100 and the offshore wind turbine 108 is maintained by the thrust of the boat 4 towards the offshore wind turbine 108 and friction between the one fender 114a and the first bumper tube 105 and between the other fender 114b and the second bumper tube 106.

When this stable engagement has been established with the apparatus in the non-braced configuration, the apparatus 100 compensates for the motion of the sea and provides a reliable and safe means for the transfer of personnel from the boat to the offshore wind turbine.

Any variation in height of the boat 104 relative to the offshore wind turbine 108, due e.g. to wave motion, is compensated for by movement of the platform 110 up and down along the vertical members 113a, 113b.

The resiliently-biased connecting mechanism 115a, 115b acts to ensure that the one fender 114a remains pushed against the first bumper tube 105 and the other fender 1146 remains pushed against the second bumper tube 106, even if the distance from the boat 104 to the offshore wind turbine 108 varies, e.g. due to sea conditions.

Accordingly, it will be appreciated that the apparatus 100 may provide a safe and secure way for personnel to get from the boat 104 to the offshore wind turbine 108 and vice versa that is able to compensate for changes in sea conditions during deployment. Consequently, use of the apparatus 100 may facilitate the safe transfer of personnel in rougher seas, thereby enabling, for example, maintenance and servicing activities to be carried out on more days per year.

Figures 6 to 9 show another example of a personnel transfer apparatus 200 for facilitating transfer of personnel, goods and/or equipment from a water-borne vessel to a relatively immobile structure. As illustrated, the personnel transfer apparatus 200 provides safe access from a boat 204 to an offshore wind turbine 208. The boat 204 may be a crew transfer vessel.

The offshore wind turbine 208 has a tower 202 fixed to the seabed and extending upwards to a height above the surface of the sea. At a top end of the tower 202, a nacelle (not shown) houses a generator, which is operably connected to a turbine (not shown) comprising a plurality of turbine blades arranged to be driven, in use, by the wind.

On a side of the tower 202, there is an access ladder 203 for maintenance personnel to climb up and down. A first bumper tube 205 is disposed on a first side of, and radially outside of, the access ladder 203. A second bumper tube 206 is disposed on a second side of, and radially outside of, the access ladder 203. The first bumper tube 205 and the second bumper tube 206 are thus disposed either side of, and forward of, the access ladder 203. As noted elsewhere herein, it is known for the bow of a crew transfer vessel to be driven hard against the first bumper tube 205 and the second bumper tube 206 to hold the crew transfer vessel sufficiently steady while personnel transfer from the crew transfer vessel to the offshore wind turbine 208 or vice versa.

The apparatus 200 comprises a staircase 207 mounted on a deck 209 of the boat 204.

The staircase 207 comprises a flight of five steps with a first platform 210 at the top thereof. A first handrail 211 is arranged on a first side of the staircase 207 A second handrail 212 is arranged on a second side of the staircase 207.

A support frame 213 comprising a scissor-lift mechanism 214 is mounted on the deck 209 of the boat 204 at a location closer to the bow of the boat 204 than the staircase 207. A second platform 215 is disposed on top of the support frame 213.

An extendable gangway 216 extends between thc first platform 210 and the second platform 215. A first gangway handrail 217 is arranged alongside a first side of the extendable gangway 216. A second gangway handrail 218 is arranged alongside a second side of the extendable gangway 216.

A first end 224 of the extendable gangway 216 is hingedly connected to the first platform 210 about a first horizontal axis. A second end 225 of the extendable gangway 216 is hingedly connected to the second platform 215 about a second horizontal axis The first horizontal axis and the second horizontal axis are parallel with each other and extend perpendicularly relative to a lengthwise direction of the extendable gangway 216.

The extendable gangway 216 may comprise two or more gangway portions arranged telescopically with each other, to enable the length of the extendable gangway 216 to vary, in use.

The second platform 215 is disposed on top of the support frame 213. A first safety fence 219 is arranged on a first side of the second platform 215. A second safety fence 220 is arranged on a second side of the second platform 215. The second platform 215 has a first open side 226 and a second open side 227 opposite the first open side 226. The first open side 226 is adjacent the second end 225 of the extendable gangway 216. In use, personnel can walk across the second platform 215 Li from the first open side 226 to the second open side 227 and on to the offshore wind turbine 208 and vice versa.

A first fender 221 and a second fender 222 are movably attached to an upper portion 223 of the support frame 213.

The first fender 221 is movable to a position arranged to contact, in use, the first bumper tube 205 When arranged to contact, in use, the first bumper tube 205, the first fender 221 is disposed adjacent a first end of the second open side 227 and outboard of the first safety fence 219. The first fender 221 may comprise one or more contact portions comprising one or more friction-producing materials. The first fender 221 has a forward-protruding wall 228a, 228b at each end, which gives the first fender 221 a generally c-shaped or u-shaped form that is arranged to assist in locating, in use, the first fender 221 on the first bumper tube 205.

The second fender 222 is movable to a position arranged to contact, in use, the second bumper tube 206. When arranged to contact, in use, the second bumper tube 206, the second fender 222 is disposed adjacent a second end of the second open side 227 and outboard of the second safety fence 220. The second fender 222 may comprise one or more contact portions comprising one or more friction-producing materials. The second fender 222 has a forward-protruding wall 229a, 229b at each end, which gives the second fender 222 a generally c-shaped or u-shaped form that is arranged to assist in locating, in use, the second fender 222 on the second bumper tube 206.

The support frame 213 comprises the scissor-lift mechanism 214. The scissor-lift mechanism 214 comprises a base portion 232. A first end of a first lift portion 233 is pivotably connected to the base portion 232. A second end of the first lift portion 233 is pivotably connected to a first rigid joining element 237. The first lift portion 233 is pivotable relative to the base portion 232 and relative to the first rigid joining element 237. A first hydraulic piston 231a extends between the base portion 232 and the first rigid joining element 237. The first rigid joining element 237 is arranged to be parallel to the base portion 232 at all times during operation of the scissor-lift mechanism 214.

A first end of a second lift portion 234 is pivotably connected to the first rigid joining element 237. A second end of the second lift portion 234 is pivotably connected to a second rigid joining element 238. The second lift portion 234 is pivotable relative to the first rigid joining element 237 and relative to the second rigid joining element 238.

A second hydraulic piston 23 lb extends between the first rigid joining element 237 and the second rigid joining element 238. The second rigid joining element 238 is arranged to be parallel to the first rigid joining element 237 at all times during operation of the scissor-lift mechanism 214 A first end of a third lift portion 235 is pivotably connected to the second rigid joining element 238. A second end of the third lift portion 235 is pivotably connected to the upper portion 223 of the support frame 213. A third hydraulic piston 231c extends between the second joining clement 238 and the upper portion 223 of the support frame 213. The upper portion 223 of the support frame 213 is arranged to be parallel to the second rigid joining element 238 at all times during operation of the scissor-lift mechanism 214.

In general, the series of the first lift portion 233, the second lift portion 234 and the third lift portion 234 has the form of a zig-zag, the pitch of which is variable by operation of the first hydraulic piston 231a, the second hydraulic piston 231b and the third hydraulic piston 231c, to vary, in use, the height of the second platform 215 relative to the first platform 210. The first hydraulic piston 231a, the second hydraulic piston 231b and the third hydraulic piston 231c are disposed in a plane perpendicular to the second platform 215 and extending in a direction from the first open side 226 to the second open side 227.

It will be appreciated that, in other implementations, the scissor-lift mechanism 214 may comprise any suitable number of lift portions arranged between the base portion 232 and the upper portion 223 of the support frame 213.

Operation of the scissor-lift mechanism is controlled by a control system (not shown) operably connected to the first hydraulic piston 231a, the second hydraulic piston 231b and the third hydraulic piston 231c.

A bottom portion of the support frame 213 is shown in detail in Figure 9. The scissor-lift mechanism 214 is mounted on a base plate 230. The base plate 230 is fixed to the deck 209 of the boat 204.

The base portion 232 of the scissor-lift mechanism 214 is pivotably coupled to the base plate 230 such that the base portion 232 can rock from side to side about a pivot axis extending in a lengthways (longitudinal) direction across the deck 209 of the boat 204. Either side of the pivot axis, a damper arrangement 236a, 236b connects the base portion 232 of the scissor-lift mechanism 214 to the base plate 230. The damper arrangements 236a, 236b can be controlled by the control system to prevent, restrict or allow pivoting of the base portion 232 of the scissor-lift mechanism 214 relative to the base plate 230.

As shown in Figure 8, the scissor-lift mechanism 214 may be collapsed between deployments of the apparatus 200. In addition, when the apparatus 200 is not in use, the first fender 221 and the second fender 222 may be moved to a stowed arrangement as illustrated in Figure 8. Between deployments, the scissor-lift mechanism 214 may be collapsed and the first fender 221 and the second fender 222 kept in the stowed arrangement, either whilst in situ attached to the deck 209 of the boat 204 or whilst not in situ. Consequently, the apparatus 200 may be stowed on board a boat or at a storage facility on land between deployments and/or transferred from one boat to another.

A control system (not shown), e.g. comprising a hydraulic system, is configured to control operation of the apparatus 200.

The apparatus 200 has a braced configuration, in which: the scissor-lift mechanism 214 holds the second platform 215 at a desired height; and the damper arrangements 236a, 236b are set to prevent pivotable motion about the pivot axis.

The control system is operable by a user to place the apparatus 200 into, and hold the apparatus 200 in, the braced configuration with the second platform 215 held at any height relative to the first platform 210.

The apparatus 200 has a non-braced configuration. in which: the scissor-lift mechanism 214 is set to permit up and down movement; and the damper arrangements 236a, 236b are set to allow pivotable motion about the pivot axis.

The control system is operable by a user to cause the apparatus 200 to switch from the braced configuration to the non-braced configuration and from the non-braced configuration to the braced configuration.

Operation of the apparatus 200 to enable transfer of personnel from the boat 204 to the offshore wind turbine 208 will now be described.

As the boat 204 is driven towards the offshore wind turbine 208, the control system is operated to place the apparatus 200 into the braced configuration with the second platform 215 held at a desired height relative to the first platform 210 and the first fender 221 and the second fender 222 forward of the bow of the boat 204 The boat 204 is then driven such that the first fender 221 is brought into contact with the first bumper tube 205 and the second fender 222 is brought into contact with the second bumper tube 206 The thrust from the boat 204 pushes the first fender 221 against the first bumper tube 205 and the second fender 222 against the second bumper tube 206.

The control system is then operated by a user to switch the apparatus 200 from the braced configuration to the non-braced configuration. In the non-braced configuration a stable engagement between the apparatus 200 and the offshore wind turbine 208 is maintained by the thrust of the boat 204 towards the offshore wind turbine 208 and friction between the first fender 221 and the first bumper tube 205 and between the second fender 222 and the second bumper tube 206 When this stable engagement has been established with the apparatus 200 in the non-braced configuration, the apparatus 200 compensates for the motion of the sea and provides a reliable and safe means for the transfer of personnel from the boat 204 to the offshore wind turbine 208.

Any variation in height of the boat 204 relative to the offshore wind turbine 208, due e.g. to wave motion, is compensated for by movement of the scissor-lift mechanism 214. The extendable gangway 216 varies in length as the scissor-lift mechanism 214 moves up and down to keep the platform stable.

Any side-to-side motion of the boat 204, e.g. due to wave motion, is compensated for by the movement of the support frame 213 relative to the base plate 230 that is permitted about the pivot axis.

Accordingly, it will be appreciated that the apparatus 200 may provide a safe and secure way for personnel to get from the boat 204 to the offshore wind turbine 208 and vice versa that is able to compensate for changes in sea conditions during deployment. Consequently, use of the apparatus 200 may facilitate the safe transfer of personnel in rougher seas, thereby enabling, for example, maintenance and servicing activities to be carried out on more days per year.

In some example implementations, a linkage mechanism other than a scissor-lift mechanism may be employed. The scissor-lift mechanism 214 constitutes an example of a suitable linkage mechanism.

In some example implementations, one or more of the fenders may comprise one or more rollers or wheels arranged to come into contact, in use, with a bumper tube on the offshore wind turbine. The roller(s) or wheel(s) may be mounted within the fender such that a portion of the roller(s) or wheel(s) protrudes from the fender. When the roller(s) or wheel(s) first come into contact with the bumper tube they may be able to rotate to allow some movement of the fender along the bumper tube. As the force pushing the roller(s) or wheel(s) increases, the roller(s) or wheel(s) may be prevented from rotating. For example, the roller(s) or wheel(s) may be pushed into the fender to a position where a brake or other mechanism prevents the roller(s) or wheel(s) from rotating.

Figures 10, II, 12 and 13 show another example of a personnel transfer apparatus 300 for facilitating transfer of personnel, goods and/or equipment from a water-borne vessel to a relatively immobile structure. The personnel transfer apparatus 300 is configured to provide safe access from a boat 304 to an offshore wind turbine The boat 304 may be a crew transfer vessel.

The apparatus 300 comprises a extendable gangway 316. A first handrail 311 is arranged on a first side of the extendable gangway 316. A second handrail 312 is arranged on a second side of the extendable gangway 316. The extendable gangway 316 comprises two gangway portions arranged telescopically with each other, to enable the length of the extendable gangway 316 to vary, in use.

A support frame 313 comprising a scissor-lift mechanism 314 is mounted within a recessed portion 308 of a deck 309 of the boat 304 at a location closer to the bow 302 of the boat 304 than the ramp 316. A first platform 310 is disposed on top of the support frame 313.

IS A first end 324 of the extendable gangway 316 is hingedly connected to the deck 309 about a first horizontal axis. A second end 325 of the extendable gangway 316 is hingedlv connected to a second platform 315 about a second horizontal axis. The first horizontal axis and the second horizontal axis are parallel with each other and extend perpendicularly relative to a lengthwise direction of the extendable gangway 316.

The extendable gangway 316 extends between the deck 309 and the second platform 315. The second platform 315 is connected to the first platform 310. in an example implementation, the first platform 310 and the second platform 315 may be integrally formed with each other.

The first platform 310 is disposed on top of the support frame 313. The first platform 310 comprises a rectangular shape with a first safety fence 319 arranged on a first side and a second safety fence 320 arranged on a second, opposing side. A third safety fence 321 is arranged on a third side and partially extends between the first safety fence 319 and the second safety fence 320. A space is present between the first safety fence 319 and the third safety fence 321 and the space extends across the region where the second platform 315 is connected to the first platform 310.

The first platform 310 has a first open side 326 opposite the third safety fence 321. The first open side 326 is arranged on an opposing side of the first platform 310 to where the extendable gangway 316 is arranged. In use, personnel can walk across the first platform 310 from the second platform 315 to the first open side 326 and on to the offshore wind turbine and vice versa.

A first fender 322 is affixed to the first platform 310 at the first open side 326. The first fender 322 extends along substantially the whole of the first open side 326.

The first fender 322 is arranged to contact, in use, the offshore wind turbine. The first fender 322 may comprise one or more contact portions comprising one or more friction-producing materials.

The scissor lift mechanism 314 is configured such that the first platform 310 may be moved between a deployed configuration, as shown in Figures 10 and 13, and a stowed arrangement, as shown partially in Figures 11 and 12.

Operation of the scissor-lift mechanism is controlled by a control system (not shown) operably connected to a first hydraulic piston arrangement 331a and a second hydraulic piston arrangement 331b. A control system (not shown), e.g. comprising a hydraulic system, is configured to control operation of the apparatus 300.

A first cover 340 is connected to the deck 309 and disposed parallel to a longitudinal axis of the extendable gangway 316. A second cover 342 is connected to the deck 309 and is arranged perpendicular and adjacent to the first cover 340. A third cover 344 is disposed on an opposing side of the ramp 316 to the first cover 340 and is parallel to and spaced apart from the second cover 342.

Each cover 340, 342, 344 is laingedly connected to the deck and configured such that each cover 340, 342, 344 may pivot from a substantially vertical position in towards the recessed portion 308. Each cover 340, 342, 344 may be operable to pivot by means of a user manually repositioning each cover 340, 342, 344. Operation of each cover 340, 342, 344 may be controlled by a control system (not shown), which may be operably connected to one or more hydraulic pistons operably connected to the covers 340, 342, 344.

As shown in Figure 12, the scissor-lift mechanism 314 may be collapsed between deployments of the apparatus 300. In the stowed configuration, the first platform 310 and the extendable gangway 316 may be arranged substantially flush with the surrounding regions of the deck 309 During deployment, the apparatus 300 has a braced configuration, in which: the scissor-lift mechanism 314 holds the first platform 310 at a desired height. The control system is operable by a user to place the apparatus 300 into, and hold the apparatus 300 in, the braced configuration with the first platform 310 held at any height relative to the deck 309. In the braced configuration, a damper arrangement (not shown) may be set to prevent pivotable motion The apparatus 300 has a non-braced configuration, in which: the scissor-lift IS mechanism 314 is set to permit up and down movement; and a damper arrangement (not shown) may be set to allow pivotable motion.

The control system is operable by a user to cause the apparatus 300 to switch from the braced configuration to the non-braced configuration and from the non-braced configuration to the braced configuration.

When moving from the deployed configuration to the stowed configuration, the scissor-lift mechanism 314 is arranged to collapse underneath the first platform 310 and fold such that it is contained in the recessed portion 308 of the deck 309 such that the scissor-lift mechanism 314 is disposed below the plane of the surrounding deck 309. In this way, in the stowed configuration, the scissor-lift mechanism 314 is contained below the plane of the surrounding deck 309. As such, when in the stowed configuration the extendable gangway 316 and the first platform 310 may prevent a user from accidentally coming into contact with the scissor-lift mechanism 314 and may also protect the scissor-lift mechanism 314 from the elements In the stowed configuration the first platform 310 and the extendable gangway 316 are lowered into the recessed portion 308 such that they are substantially flush with the surrounding regions of the deck 309. The first handrail 311 and second handrail 312 are operable to pivot such that they are substantially parallel with the extendable gangway 316. The third safety fence 321, in the stowed configuration, is configured to pivot towards the first platform 310 such that it is substantially parallel with the first platform 310.

In some example implementations, the first safety fence 319 and the second safety fence 320 may be arranged to extend vertically from the first platform 310 when in the stowed configuration. In this way, the first safety fence 319 and the second safety fence 320 may continue to act as safety barriers and help prevent users from walking onto the first platform 310 when the apparatus 300 is in the stowed configuration.

In some embodiments, the first safety fence 319 and the second safety fence 320 are also operable to pivot and fold onto the first platform 310. In this way, the apparatus 300 may be substantially flush with the adjacent regions of the deck 309 when the apparatus 300 is in the stowed configuration. I5

Figure 11 shows the apparatus 300 in a position between the stowed configuration and the deployed configuration. The extendable gangway 316 is arranged such that it is substantially flush with the surrounding regions of the deck 309. The first platform 310 has pivoted such that the first open side 326 is near to the deck 309 whilst the opposing side is further away from the deck 309. In addition, the first safety fence 319, the second safety fence 320 and the third safety fence 321 have all been folded such that they are substantially parallel with the first platform 310. in some embodiments, the first platform 310 may be connectable to and disconnectable from the second platform 315.

The first cover 340 comprises a similar length and width to the extendable gangway 316, in this way, when the extendable gangway 316 is in the stowed configuration, the first cover 340 may be pivoted such that it at least partially covers the extendable gangway 316. Alternatively, the first cover 340 may be maintained in a substantially vertical configuration and may help to prevent users accidentally walking on the extendable gangway 316 when the apparatus 300 is in the stowed configuration. When pivoted towards the extendable gangway 316, the first cover 340 may pivot such that it is substantially flush with adjacent portions of the deck 309.

The second cover 342 and the third cover 344 are operable to pivot such that they may at least partially cover the first platform 310 when the apparatus 300 is in the stowed configuration. In some example implementations, the second cover 342 and the third cover 344 may be maintained in a substantially vertical configuration and in this way may help to prevent users accidentally walking on the first platform 310 when the apparatus 300 is in the stowed configuration In use, the first cover 340, the second cover 342 and the third cover 344 may remain in a substantially vertical orientation whilst the extendable gangway 316 and the first platform 310 are in a deployed configuration In this way, the first cover 340, the second cover 342 and the third cover 344 may help prevent users from accidentally contacting the scissor-lift mechanism 314 when the apparatus 300 is in the deployed configuration. In addition, the first cover 340, the second cover 342 and the third cover 344 may help protect the scissor-lift mechanism 314 from the elements during deployment of the apparatus 300.

When the scissor-lift mechanism 314 is operated such that the extendable gangway 316 and the first platform 310 are lowered into the stowed configuration, the first cover 340, the second cover 342 and the third cover 344 may remain in a substantially vertical orientation. The first handrail 311 and the second handrail 312 may be folded onto the extendable gangway 316 and the first safety fence 319, the second safety fence 320 and the third safety fence 321 may be folded onto the first platform 310. The first cover 340, the second cover 342 and the third cover 344 may then be folded towards the extendable gangway 316 and the first platform 310 so as to at least partially cover the extendable gangway 316, the first platform 310, the first handrail 311, the second handrail 312, the first safety fence 319, the second safety fence 320 and the third safety fence 321.

In some embodiments, any one or more of the first cover 340, the second cover 342 and the third cover 344 may not be present. In some embodiments, one or more further covers may be present.

Operation of the apparatus 300 to enable transfer of personnel, goods and/or equipment from the boat 304 to a relatively immobile structure such as an offshore wind turbine will now be described. :3 3

As the boat 204 is driven towards the relatively immobile structure, the control system is operated to place the apparatus 300 into the braced configuration with the first platform 310 held at a desired height relative to the deck 309 and the first fender 322 forward of the bow 302 of the boat 304.

The boat 304 is then driven such that the first fender 322 is brought into contact with a portion of the relatively immobile structure, e.g. one or more bumper tubes. The thrust from the boat 304 pushes the first fender 332 against the portion of the relatively immobile structure.

The control system is then operated by a user to switch the apparatus 300 from the braced configuration to the non-braced configuration In the non-braced configuration a stable engagement between the apparatus 300 and the relatively immobile structure is maintained by the thrust of the boat 304 towards relatively immobile structure and IS friction between the first fender 322 and the portion of the relatively immobile structure in contact with the first fender 322 When this stable engagement has been established with the apparatus 300 in the non-braced configuration, the apparatus 300 compensates for the motion of the sea and provides a reliable and safe means for the transfer of personnel, goods and/or equipment from the boat 304 to the relatively immobile structure.

Any variation in height of the boat 304 relative to the relatively immobile structure, due e.g. to wave motion, is compensated for by movement of the scissor-lift mechanism 314. The extendable gangway 316 varies in length as the scissor-lift mechanism 314 moves up and down to keep the platform stable.

Any side-to-side motion of the boat 304, e.g. due to wave motion, may also be compensated for.

Accordingly, it will be appreciated that the apparatus 300 may provide a safe and secure way for personnel, goods and/or equipment to get from the boat 304 to the relatively immobile structure and vice versa that is able to compensate for changes in sea conditions during deployment. Consequently, use of the apparatus 300 may facilitate the safe transfer of personnel, goods and/or equipment in rougher seas, thereby enabling, for example, maintenance and servicing activities to be carried out on more days per year.

In some example implementations, a linkage mechanism other than a scissor-lift mechanism may be employed. The scissor-lift mechanism 314 constitutes an example of a suitable linkage mechanism.

In some example implementations, the apparatus 300 may comprise more than one fender. One or more of the fenders may comprise one or more rollers or wheels arranged to come into contact, in use with a bumper tube on the offshore wind turbine. The roller(s) or wheel(s) may be mounted within the fender such that a portion of the roller(s) or wheel(s) protrudes from the fender. When the roller(s) or wheel(s) first come into contact with the bumper tube they may be able to rotate to allow some movement of the fender along the bumper tube. As the force pushing the roller(s) or wheel(s) increases, the roller(s) or wheel(s) may be prevented from rotating For example, the roller(s) or wheel(s) may be pushed into the fender to a position where a brake or other mechanism prevents the roller(s) or wheel(s) from rotating in some example implementations, an end of the extendable gangway 316 may be connected directly to the first platform 310. In such an implementation, the apparatus 300 may not comprise a second platform 315.

Figures 14 and 15 show another example of a personnel transfer apparatus 300'. The apparatus 300' is very similar to the apparatus 300 described above and operates in exactly the same way. Like features are indicated using like reference numerals with a prime ('). One difference between the personnel transfer apparatus 300' and the personnel transfer apparatus 300 is that the first handrail 311', the second handrail 312' and the third safety fence 321' comprise solid safety barriers portions.

The preceding discussion relating to the personnel transfer apparatus 300 and Figures 10 to 13 applies essentially to the personnel transfer apparatus 300'.

Figure 16 illustrates a system 1000 for assisting a skipper of a crew transfer vessel to locate a target portion of an offshore wind turbine. The target portion of the offshore wind turbine may typically comprise an access ladder with a bumper tube either side of the access ladder.

The system 1000 includes a lidar camera 1001 arranged to capture lidar images of the target portion of the offshore wind turbine and a visual camera 1002 arranged to capture visual images of the target portion of the offshore wind turbine. A processor 1003 is operably connected to the lidar camera 1001 and the visual camera 1002. The processor 1003 is arranged to receive lidar image data from the lidar camera 1001 and visual image data from the visual camera 1002. The processor 1003 operates to combine the lidar image data and the visual image data to produce a combined image comprising the lidar image data and the visual image data. The combined image is sent from the processor 1003 to an image display 1004 such as a monitor.

Figure 17 shows schematically a visual image of a target portion of an offshore wind turbine 1108 comprising an access ladder 1103 with a bumper tube 1105, 1106 either side of the access ladder 1103.

Figure 18 shows schematically a lidar image corresponding to the visual image of Figure 17.

Figure 19 shows schematically a combined image comprising image data from the visual image of Figure 17 and the lidar image of Figure 18.

The system 1000 may help a skipper of a crew transfer vessel to correctly locate a target portion of an offshore wind turbine in times of poor visibility, e.g. due to relatively rough sea conditions and/or poor light conditions. At present, a person standing on deck at or near the bow of the crew transfer vessel talks to the skipper in the bridge via a communications device such as a walkic talkie, to help the skipper guide the crew transfer vessel towards the target portion of the offshore wind turbine. In rough sea conditions and/or poor light conditions, it may not be safe for a person to perform this task. Use of the system 1000 may provide useful additional information to the skipper and/or may make it unnecessary to have a person standing on deck at or near the bow of the crew transfer vessel.

Use of the system 1000 may improve the efficiency and/or safety of personnel transfer operations from a boat to an offshore wind turbine and vice versa. In addition, use of the system 1000 may facilitate such personnel transfer operations in sub-optimal conditions and may consequently help to expand the window for carrying out such personnel transfer operations.

Use of the system 1000 in combination with a personnel transfer apparatus disclosed herein (e.g. the personnel transfer apparatus 1, the personnel transfer apparatus 100 or the personnel transfer apparatus 200) may be advantageous in maintaining safety and/or expanding the window for carrying out personnel transfer operations from a water-borne vessel to a relatively immobile structure such as an offshore wind turbine.

Figure 20 is a chart showing significant wave height in seas around the UK against cumulative number of days throughout the year. Significant wave height, measured in metres, is plotted on the y-axis. Cumulative number of days throughout the year is plotted on the x-axis.

As indicated by a first line 141, there are typically 200 days in a year when the significant wave height in seas around the UK is 1.5 metres or less. Hence, personnel transfer operations from crew transfer vessels to/from offshore wind turbines can only take place on 200 days in a typical year.

As indicated by a second line 142, there are typically 310 days in a year when the significant wave height in seas around the UK is 3 metres or less.

Use of the personnel transfer apparatus disclosed herein may enable safe and secure personnel transfer operations from crew transfer vessels to/from offshore wind turbines in rougher seas than current regulations allow. For instance, use of the personnel transfer apparatus disclosed herein may enable safe and secure personnel transfer operations from crew transfer vessels to/from offshore on days when the significant wave height is 3 metres or less Consequently, the number of days available for personnel transfer operations in a typical year may be over 50% more (310 days versus 200 days) than under current regulations, which do not allow such operations to take place in waves of more than 1.5 metres. It has been estimated that such an increase in the number of days available for personnel transfer operations could decrease the cost of electricity generation from offshore wind turbines by up to 3% [Refl.

While the examples described herein have concerned personnel transfer operations from a boat to/from an offshore wind turbine, it will be appreciated that the teachings of the present disclosure may be implemented in many other scenarios. in general, the teachings of the present disclosure may be implemented in any scenario involving the transfer of personnel from a water-borne vessel to a relatively immobile structure.

An offshore wind turbine is an example of an applicable relatively immobile structure. Other examples of a relatively, immobile structure will be apparent to the person skilled in the art and may include, for example, a harbour wall, an offshore rig or platform, any fixed offshore structure or a relatively large water-borne vessel such as a relatively large ship. In the case of the transfer of personnel from a typical crew transfer vessel to a large ship, the large ship will be relatively immobile compared with the crew transfer vessel The teachings of the present disclosure may provide several advantages.

For example, use of the apparatus disclosed herein may facilitate the safe and secure transfer of personnel and/or equipment from a water-borne vessel to a relatively immobile structure, even in relatively rough seas, e.g seas with a significant wave height of up to or more than 3 metres.

Another advantage compared with driving the boat hard against the relatively immobile structure is that use of the apparatus disclosed thereon may reduce the push on loads experienced by the relatively immobile structure. Accordingly, the risk of damaging the relatively immobile structure, e.g. an offshore wind turbine, may be reduced.

Another advantage of using the apparatus disclosed herein is that the chance of the vessel colliding with the relatively immobile structure in large swells may be reduced or even eliminated Use of the apparatus disclosed herein may increase the overall speed and efficiency of transferring personnel and/or equipment from a water-borne vessel to a relatively immobile structure.

The apparatus disclosed herein may be relatively cost-effective and simple to maintain between deployments, either offshore or on shore.

It win be understood that the invention is not limited to the embodiments described above. Various modifications and improvements can be made without departing from the concepts disclosed herein Except where mutually exclusive, any of the features may be employed separately or in combination with any other features and the disclosure extends to all combinations and sub-combinations of one or more features disclosed herein. I5

Claims

CLAIMS1. An apparatus for transfer of personnel, goods and/or equipment from a water-borne vessel to a relatively immobile structure comprising: a platform accessible from the water-borne vessel; one or more fenders at least partially disposed forward of the platform and arrangable to be brought into contact, in use, with the relatively immobile structure; wherein the apparatus has a braced configuration, in which the platform is held in a fixed position relative to the water-borne vessel; and the apparatus has a non-braced configuration, in which the platform can move in at least a substantially vertical direction relative to the water-borne vessel; and the apparatus comprises a control system configured to allow user selection of the braced configuration and the non-braced configuration; wherein, in use, thrust of the water-borne vessel pushes the fender(s) against the relatively immobile structure to maintain a stable engagement between the apparatus and the relatively immobile structure so that when the stable engagement is being maintained and the apparatus is in the non-braced configuration the platform remains relatively stationary relative to movement of the water-borne vessel.
2. An apparatus according to claim I, wherein, in the non-braced configuration, the platform is able to move in one or more further directions relative to the waterborne vessel.
3. An apparatus according to claim 1 or claim 2, wherein one or more of the fenders have one or more contact portions, which may comprise one or more friction-producing materials.
4. An apparatus according to claim I, claim 2 or claim 3, wherein the fender(s) is/are each shaped and dimensioned to cooperate with an external portion of the relatively immobile structure.
5. An apparatus according to any one of claims 1 to 4, wherein the fender(s) is/are operably connected to one or more biasing members or mechanisms arranged to urge the fender(s) against the relatively immobile structure.
6. An apparatus according to any one of the preceding claims, wherein one or more of the fenders comprise one or more rollers or wheels arranged to come into contact, in use, with the relatively immobile structure.
7. An apparatus according to claim 6, wherein the roller(s) or wheel(s) is/are mounted within the fender such that a portion of the roller(s) or wheel(s) protrudes from the fender so that: when the roller(s) or wheel(s) first come into contact with the relatively immobile structure it/they is/are able to rotate to allow some movement of the fender along a surface of the relatively immobile structure; and as the force pushing the fender(s) against the relatively immobile structure increases the roller(s) or wheel(s) is/are prevented from rotating.
8. An apparatus according to any one of the preceding claims, wherein one or more of the fenders is/are movable between a stowed arrangement and a deployment arrangement, in which the fender(s) is/are at least partially disposed forward of the platform and arranged to be brought into contact, in use, with the relatively immobile structure.
9. An apparatus according to any one of the preceding claims comprising a gangway, wherein an end of the gangway is hingedly connected to the platform.
10. An apparatus according to claim 9, wherein the gangway has a variable length.
11. An apparatus according to claim 10 comprising a resilient biasing system configured to act lengthways (longitudinally) along the gangway.
12. An apparatus according to any one of the preceding claims, wherein the apparatus comprises a first platform and a second platform, the second platform being the platform, which is held in a fixed position relative to the water-borne vessel when the apparatus is in the braced configuration and which can move in at least a substantially vertical direction relative to the water-borne vessel when the apparatus is in the non-braced configuration.
13. An apparatus according to claim 12, comprising a gangway, c.g an extendable gangway, extending between the first platform and the second platform
14. An apparatus according to claim 13, wherein a first end of the gangway is hingedly connected to the first platform and a second end of the gangway is hingedly connected to the second platform.
15. An apparatus according to claim 13 or claim 14, wherein the gangway is rotatable relative to the first platform about an axis passing perpendicularly through the first platform.
16. An apparatus according to any one of the preceding claims comprising a ramp, a ladder or a staircase arranged to provide access from the water-borne vessel to the platform or from the water-borne vessel to the or a first platform.
17. An apparatus according to any one of the preceding claims, wherein the I5 apparatus is collapsible at least in part.
18. An apparatus according to any one of the preceding claims, wherein the platform is mounted on a scissor-lift mechanism and the control system is arranged to act on the scissor-lift mechanism to allow user selection of the braced configuration and the non-braced configuration.
19. An apparatus according to claim I8, wherein a base portion of the scissor-lift mechanism is pivotably coupled to a stationary portion of a support frame or the water-borne vessel such that, in use, the base portion can rock from side to side about a pivot axis extending in a lengthways (longitudinal) direction across the water-borne vessel.
20. An apparatus according to claim 19, wherein, either side of the pivot axis, a damper arrangement connects the base portion of the scissor-lift mechanism to the stationary portion of the or a support frame or the water-borne vessel.
21 A system for assisting a skipper of a water-borne vessel to locate a target portion of a relatively immobile structure when driving the water-borne vessel towards the relatively immobile structure, wherein the system comprises: a lidar camera arranged to capture lidar images of the target portion of the relatively immobile structure; a visual camera arranged to capture visual images of the target portion of the relatively immobile structure; a processor operably connected to the lidar camera and the visual camera; and an image display operably connected to the processor; wherein the processor is arranged to: receive lidar image data from the lidar camera and visual image data from the visual camera; combine the lidar image data and the visual image data to produce combined images comprising the lidar image data and the visual image data; and send the combined images to the image display.
22. A water-borne vessel with an apparatus according to any one of claims 1 to 20 mounted thereon and/or a system according to claim 21 installed thereon.IS
23. A water-borne vessel according to claim 22, wherein at least one of the following applies: (i) the water-borne vessel is a boat; and/or (ii) the water-borne vessel is a crew transfer vessel.
24. A method of transferring personnel, goods and/or equipment from a water-borne vessel to a relatively immobile structure comprising: driving a water-borne vessel with an apparatus according to any one of claims 1 to 20 mounted thereon towards a relatively immobile structure, so as to push the fender(s) against the relatively immobile structure with the apparatus in the braced configuration, wherein thrust of the water-borne vessel establishes and maintains a stable engagement between the apparatus and the relatively immobile structure: and operating the control system to select the non-braced configuration so that while the stable engagement is maintained and the apparatus is in the non-braced configuration the platform remains relatively stationary relative to movement of the water-borne vessel, thereby enabling the transfer of personnel, goods and/or equipment from the water-borne vessel to the relatively immobile structure and/or vice versa.
25. A method of assisting a skipper of a water-borne vessel in locating a target portion of a relatively immobile structure comprising: driving a water-borne vessel with a system according to claim 21 installed thereon towards the relatively immobile structure; capturing, using the lidar camera, lidar images of the target portion of the relatively immobile structure; capturing, using the visual camera, visual images of the target portion of the relatively immobile structure; receiving, at the processor, lidar image data from the lidar camera and visual image data from the visual camera; combining, in the processor, the lidar image data and the visual image data to produce combined images comprising the lidar image data and the visual image data; and sending the combined images to the image display.IS