GB2491461A

GB2491461A - Improved offshore access apparatus

Info

Publication number: GB2491461A
Application number: GB1209371.2A
Authority: GB
Inventors: Robert Macdonald
Original assignee: Individual
Current assignee: Individual
Priority date: 2011-05-26
Filing date: 2012-05-28
Publication date: 2012-12-05
Anticipated expiration: 2032-05-28
Also published as: GB2491461B; GB201108892D0; GB201209371D0

Abstract

A passageway for connecting a vessel 12 to a wind turbine 14 comprises a plurality of passageway sections 16a, 16b, 16c arranged in a telescopic relationship and being relatively movable between a contracted position and an extended position. The passageway further comprises a first connection 18 adapted to connect a first passageway section to a vessel, a second connection 20 adapted to connect a second passageway section to a wind turbine and a biasing device adapted to bias the passageway sections to the contracted position. Also disclosed is a connection device for attaching to an object with first and second biased gripping devices 40a and 40b that are moved from a closed position, to which they are biased, to an open position by an impact between the connection device and an object.

Description

IMPROVED ACCESS APPARATUS

Field of the Invention

The present invention relates to a passageway for connection a sea-going vessel to a substantially stationary object and a connection device for connecting a passageway to a substantially stationary object. Particularly the invention relates to a passageway for connecting a boat to a wind turbine.

Background to the Invention

Wind turbines are becoming more prevalent in the seas and oceans around the coast of many countries. Wind turbines are complex pieces of equipment designed to work in extremely hostile environments. To maintain efficient operation, the turbines require regular maintenance. Obtaining access to the turbines to perform maintenance operations generally involves the transfer of a maintenance engineer from a vessel such as a boat to the turbine.

The maintenance engineer generally obtains access by jumping from the boat onto a platform or ladder mounted to the side of the turbine housing. Such a manoeuver requires the boat to be positioned as close as possible to the turbine and there is the possibility of collision between the boat and the turbine or the maintenance engineer falling into the sea. Due to the risks of the manoeuver, it is only performed in generally calm conditions and, as such, there is limited opportunity to carry out maintenance operations.

Being unable to access the turbine due to weather conditions can be particularly costly if the wind turbine has failed and is not producing electricity. In such circumstances, being unable to access the wind turbine results in the turbine sitting idle and being unable to generate income.

I

Summary of the Invention

According to a first aspect of the present invention there is provided a passageway for connecting a vessel to a wind turbine, the passageway comprising: a plurality of passageway sections, the passageway sections being in a telescopic relationship, the sections being relatively movable between a contracted position and an extended position; a first connection adapted to connect a first passageway section to a vessel; a second connection adapted to connect a second passageway section to a wind turbine; and a biasing device adapted to bias the passageway sections to the contracted position.

In an embodiment of the present invention, providing a passageway in which the passageway sections are biased to the contracted position means that when the passageway is attached to a wind turbine, the vessel can extend the passageway by pulling away from the wind turbine with a force greater than the biasing force. A vessel which is actively pulling against a force is generally more stable than one which is under no load.

In one embodiment the first connection is a pivotal connection.

The first connection may comprise at least one pivot axis.

The first connection may comprise a plurality of pivot axes.

The first connection may comprise two pivot axes.

The first connection may comprise a pitching pivot axis. Pitching occurs when the vessel pivots around an axis which is perpendicular to the longitudinal axis of the vessel and perpendicular to the sides of the vessel.

The passageway first connection may comprise a roll pivot axis. A vessel will roll around the longitudinal axis of the vessel. Providing a connection which allows the passageway to remain relatively stable as the vessel rolls and pitches, provides a stable environment for a user crossing the passageway. The third type of movement a vessel can exhibit is sway. Sway is where a vessel rotates around an axis which is perpendicular to the longitudinal axis of the vessel and extends through the longitudinal axis in a direction parallel to the sides of the vessel. Due to the nature of the design in which the vessel is under load from the engine to pull away from the turbine to prevent the passageway from contracting under the effect of the biasing device, sway is minimised and in some embodiments does not need to be catered for.

The second connection may comprise at least one pivot axis.

The second connection may comprise a plurality of pivot axes.

The second connection may comprise three pivot axes.

The second connection may comprise a pitch pivot axis.

The second connection may comprise a roll pivot axis.

The second connection may comprise a sway pivot axis. A sway pivot axis is provided on the second connection as the vessel and the passageway may drift as a unit either side of a neutral position in which the vessel is perpendicular The second connection may be a universal joint.

In an alternative embodiment, the second connection may only comprise two pivot axes, for example, a pitch pivot axis and a sway pivot axis. In such an embodiment as the vessel pictures, the passageway remains substantially horizontal as the vessel will pitch with respect to the first connection, the second connection present the pitch being transferred to the passageway. In this way, having different pivot axes at each connection point permits the passageway orientation to be controlled, the effect of the movement of the vessel on the passageway being reduced.

The second connection may be adapted to connect to a wind turbine surface structure.

The wind turbine surface structure may be a ladder.

The second connection may be adapted to be connected to a wind turbine structure upright. The second connection may be adapted to be connected to any

suitable structure.

The second connection may include at least one gripping device for gripping a portion of a wind turbine.

The second connection may include a plurality of gripping devices.

The gripping devices may be self lockable.

The gripping devices may comprise grips biased to a locked position.

The gripping devices may be resilient such that they will deflect on impact with a structure to be gripped sufficiently to pass by the structure to be gripped and then grip on to the back of the structure to be gripped.

The gripping devices may be biased to the locked position by at least one spring.

The gripping devices may be moveable to an unlocked position.

The second connection device may have a release mechanism.

The passageway may comprise an actuator adapted to actuate the second connection device to the unlocked position.

The actuator device may, in use, be in the form of a cable extending from the second connection device back to the vessel.

The passageway may comprise at least three passageway sections. Where there are three passageway sections the passageway may comprise a first, second and third section.

The passageway may be extendible to in excess of ten metres.

The biasing device may comprise a winch having a cable.

The biasing device may be fixed relative, in use, to the deck of the vessel.

The biasing device may be located adjacent the first connection.

The cable may connect the winch to the second connection and/or the second passageway section. In either case retracting the winch will move the passageway to the contracted configuration.

In the extended position, the winch may be activated to apply a contraction force to contract the passageway to the contracted position.

The second connection may comprise a unidirectional securing system.

The unidirectional securing system may be adapted to permit the second connection, when connected to a wind turbine surface structure, to move in an upward direction, away from the surface of the water, whilst the boat rises and falls but prevents the second connection from moving downwards towards the water surface, such an arrangement ensures the second connection cannot drop into the surface of the water.

According to a second aspect of the present invention there is provided a connection device for attaching to an object, the connection device comprising: a first gripping device, and a second gripping device, the first and second gripping devices being moveable from a closed position in which the gripping devices are adapted to attach to an object, and an open position in which the gripping devices are adapted to release from the object, the gripping devices being biased to the closed position and being moveable to the open position by application of a force to the gripping devices created by an impact between the connection device and an object.

According to a third aspect of the present invention there is provided an connection device for attaching to an object, the connection device comprising: a first gripping device, and a second gripping device, the first and second gripping devices being adapted to at least partially encircle an object, the gripping devices defining an opening, the gripping devices being resiliently separable to increase the size of the opening to receive an object through the opening by application of a force to the gripping devices created by an impact between the connection device and an object.

According to a fourth aspect of the present invention there is provided a method of attaching a sea-going vessel to a structure, the method comprising the steps of: engaging a first end of a telescopic passageway to a structure, and applying a substantially constant pull force to the second end of the passageway to extend the passageway and stabilize the vessel.

According to a fifth aspect of the present invention there is provided a method of attaching to an object, the method comprising resiliently deforming first and second gripping devices apart from the rest position to receive an object there between by application of an impact force with the object.

It will be understood that preferred features listed in respect of the first aspect of the present invention may be equally applicable to the second, third, fourth and fifth aspects and are not repeated for brevity.

Brief Description of the Drawings

An embodiment of the present invention will now be described with reference to the accompanying drawings in which: Figure 1 is a side view of a passageway for connecting a vessel to a wind turbine shown in use, according to a first embodiment of the present invention; Figure 2 is a perspective view of the passageway of Figure 1; Figure 3 is a close up perspective view of the first connection device of the passageway of Figure 1; Figure 4 is a top view of the second connection device of the passageway of Figure 1; Figures 5a to Sf are a series of top views of the second connection device of Figure 1 showing the attachment of the second connection device to the wind turbine; and Figures 6a and 6b are side views of the second connection device of the passageway of Figure 1 shown engaged with a wind turbine structure.

Detailed Description of the Drawings

Reference is firstly made to Figure 1, a side view of a passageway, generally indicated by reference numeral 10 for connecting a vessel 12 to a wind turbine 14, and Figure 2, a perspective view of the passageway 10, vessel 12 and wind turbine 14 of Figure 1.

The passageway 10 comprises a plurality of passageway sections 16a, 16b, 16c, the passageway sections 16 being in a telescopic relationship, the sections 16 being relatively moveable between a contracted position (not shown) and an extended position, shown in Figures 1 and 2.

The passageway 10 further comprises a first connection 18 adapted to connect a first passageway section 16a to the vessel 12, and a second connection 20 adapted to connect a second passageway section 16c to the wind turbine 14, and particularly to a wind turbine ladder 50. A biasing device 22 is provided to bias the passageway sections 16 to the contracted position.

The biasing device 22 is more clearly shown in Figure 3, a close up perspective view of the biasing device 22, the first connection device 18 and the first passageway section 16a.

The biasing device 22 is in the form of a winch 24 which includes a cable 26 The cable 26 extends along the length of the passageway 16 and is attached to the second connection device 20. The winch 24 applies a constant force to the cable 26 which is in turn transmitted to the passageway sections 16 through the second connection device via the cable 26. The force biases the passageway sections 16 to a contracted configuration in which the passageway sections 16 have moved telescopically to define the shortest length of passageway 16. Such an arrangement requires the vessel 12 to apply a force opposite to the biasing force and greater than the biasing force to the passageway 16 to extend the passageway 16 to an extended configuration (shown in Figure 1). In practice the extended configuration is achieved by the vessel 12 driving away from the wind turbine 14, with the result that the vessel 12 and the wind turbine 14 are spaced apart a safe distance and connected by the extended passageway 16, as shown in Figure 1.

The first connection device 18 is a two pivot axis connection, the first pivot axis being perpendicular to the longitudinal axis of the vessel 12 and perpendicular to the sides of the vessel 12. This first pivot axis 30 compensates for the vessel 12 pitching.

The second pivot axis 32 extends along the longitudinal axis of the passageway 16 minimising the effect of vessel roll on the passageway 16. The first connection device 18 has only these two pivot axes 30,32 and not a third pivot axis to compensate for sway, because the force of the vessel 12 driving away from the wind turbine 14 will make the vessel 12 less prone to experiencing sway.

Reference is now made to Figure 4 a top view of the second connection device 20 of the passageway of Figure 1. The second connection device 20 comprises first and second gripper arms 40a, 40b mounted to a connection device frame 42 and connected by a gripper arm control cable 41. The gripper arms 40 are spring loaded to a locked position L" and are moveable to an unlocked position "U" shown in broken outline. The arms 40 cab be moved to the unlocked position either by application of a force to the leading edges of the gripper arms 40 (as will be discussed) or application of a force from the vessel to the gripper arm control cable 41, moving the cable 41 to the position shown in broken outline. The second connection device 20 further includes first and second engagement wheels 44a, 44b. The purpose of these wheels 44 will be discussed in due course.

The second connection device 20 is connected to the second passageway section 16c by a universal joint 46. The universal joint 46 has three pivot axes to compensate for pitching, rolling and swaying. As the first connection device 18 does not compensate for sway, any sway force experienced by the vessel 12 will cause the vessel 12 and the passageway 16 to sway together around the universal joint 46 sway pivot axis.

Referring to Figure 5a to Sf, a sequence of top views of the second connection device 20 showing the vessel 12 connecting to the wind turbine 14, the vessel 12 moves towards the wind turbine 14 with the second connection device 20 aligned with a wind turbine ladder 50. In this aligned position, the passageway longitudinal axis 52 is perpendicular to the ladder longitudinal axis 64 (Figure 5a, Figure Sb).

The ladder 50 comprises first and second ladder uprights 58a, 58b. On engagement with a ladder upright 58a, 58b, the gripper arms 40 separate under the action of the impact of the ladder uprights 58 on the gripper arm leading edges 56a, 56b.

The leading edges 56 are curved such that the impact force pushes them apart against the bias of spring (not shown) to an unlocked position (Figure Sc -Se). Once the leading edges 56 of the gripper arms 40 pass the ladder uprights 58, they spring back into the locked position (Figure Sf), securing the ladder uprights 58 within the second connection device 20 and engaged with the engagement wheels 44.

Reference is finally made to Figures 6a and 6b, side views of the second connection device 20 of the passageway 10 of Figure 1 shown engaged with wind turbine ladder SO. Particularly this figure shows the arrangement of the gripper arms 40, the engagement wheels 44 and a downwardly depending frame skirt 60. This arrangement allows the connection device 20 to rise up the ladder SO (Figure 6a) as the vessel 12 pitches upwards, but prevents the second connection device 20 from moving down the ladder SO as the vessel 12 pitches downwards. This ensures the end of the passageway 10, which is connected to the wind turbine 14, does not dip into the water as the vessel 12 pitches. The increased height of the second connection device 20 is accommodated by the universal joint pitch axis between the second connection device and the second passageway section 16c. Various modifications and improvements may be made to the above described embodiment without departing from the scope of the invention. For example, the second connection device may be designed to only accommodate sway and pitching, and not accommodate roll. Such an arrangement would allow the vessel to roll with respect to the passageway, the passageway remaining in a substantially constant orientation with respect to its roll axis, preventing a person crossing passageway from being tipped off the side of passageway.

Claims

Claims 1. A passageway for connecting a vessel to a wind turbine, the passageway comprising: a plurality of passageway sections, the passageway sections being in a telescopic relationship, the sections being relatively movable between a contracted position and an extended position; a first connection adapted to connect a first passageway section to a vessel; a second connection adapted to connect a second passageway section to a wind turbine; and a biasing device adapted to bias the passageway sections to the contracted position.
2. The passageway of claim 1, wherein the first and/or second connection is a pivotal connection.
3. The passageway of claim 2, wherein the first connection comprises at least one pivot axis.
4. The passageway of claim 3, wherein the first connection comprises a plurality of pivot axes.
5. The passageway of claim 4, wherein the first connection comprises two pivot axes.
6. The passageway of any of claims 3 to 5, wherein the first connection comprises a pitching pivot axis.
7. The passageway of any of claims 3 to 6, wherein the passageway first connection comprises a roll pivot axis.
8. The passageway of any of claims 3 to 7, wherein the second connection comprises at least one pivot axis.
9. The passageway of claim 8, wherein the second connection comprises a plurality of pivot axes.
10. The passageway of claim 9, wherein the second connection comprises three pivot axes.
11. The passageway of any of claims 8 to 10, wherein the second connection comprises a pitch pivot axis.
12. The passageway of any of claims 8 to 11, wherein the second connection comprises a roll pivot axis.
13. The passageway of any of claims 8 to 12, wherein the second connection comprises a sway pivot axis.
14. The passageway of any of claims 8 to 13, wherein the second connection is a universal joint.
15. The passageway of either of claims 8 or 9, wherein the second connection comprises two pivot axes.
16. The passageway of any preceding claim, wherein the second connection is adapted to connect to a wind turbine surface structure.
17. The passageway of claim 16, wherein the wind turbine surface structure is a ladder.
18. The passageway of either of claims 16 or 17, wherein the second connection is adapted to be connected to a wind turbine structure upright.
19. The passageway of any preceding claim, wherein the second connection includes at least one gripping device for gripping a portion of a wind turbine.
20. The passageway of claim 19, wherein the second connection includes a plurality of gripping devices.
21. The passageway of claim 20, wherein the gripping devices are self-lockable.
22. The passageway of either of claims 20 or 21, wherein the gripping devices comprise grips biased to a locked position.
23. The passageway of any of claims 20 to 22, wherein the gripping devices are resilient such that they will deflect on impact with a structure to be gripped sufficiently to pass by the structure to be gripped and then grip on to the back of the structure to be gripped.
24. The passageway of either of claims 22 or 23, wherein the gripping devices are biased to the locked position by at least one spring.
25. The passageway of any of claims 22 to 24, wherein the gripping devices is moveable to an unlocked position.
26. The passageway of claim 25, wherein the second connection device has a release mechanism.
27. The passageway of claim 26, wherein the passageway comprises an actuator device adapted to actuate the second connection device to the unlocked position.
28. The passageway of claim 27, wherein the actuator device is, in use, in the form of a cable extending from the second connection device back to the vessel.
29. The passageway of any preceding claim, wherein the passageway comprises at least three passageway sections.
30. The passageway of any preceding claim, wherein the passageway is extendible to in excess often metres.
31. The passageway of any preceding claim, wherein the biasing device comprises a winch having a cable.
32. The passageway of claim 31, wherein the biasing device is fixed relative, in use, to the deck of the vessel.
33. The passageway of either of claims 31 or 32, wherein the biasing device is located adjacent the first connection.
34. The passageway of any of claims 31 to 33, wherein the cable connects the winch to the second connection and/or the second passageway section.
35. The passageway of any of claims 31 to 34, wherein n the extended position, the winch is activated to apply a contraction force to contract the passageway to the contracted position.
36. The passageway of any preceding claim, wherein the second connection comprises a unidirectional securing system.
37. The passageway of claim 36, wherein the unidirectional securing system is adapted to permit the second connection, when connected to a wind turbine surface structure, to move in an upward direction, away from the surface of the water, whilst the boat rises and falls but prevents the second connection from moving downwards towards the water surface.
38. A connection device for attaching to an object, the connection device comprising: a first gripping device, and a second gripping device, the first and second gripping devices being moveable from a closed position in which the gripping devices are adapted to attach to an object, and an open position in which the gripping devices are adapted to release from the object, the gripping devices being biased to the closed position and being moveable to the open position by application of a force to the gripping devices created by an impact between the connection device and an object.
39. A connection device for attaching to an object, the connection device comprising: a first gripping device, and a second gripping device, the first and second gripping devices being adapted to at least partially encircle an object, the gripping devices defining an opening, the gripping devices being resiliently separable to increase the size of the opening to receive an object through the opening by application of a force to the gripping devices created by an impact between the connection device and an object.
40. A method of attaching a sea-going vessel to a structure, the method comprising the steps of: engaging a first end of a telescopic passageway to a structure, and applying a substantially constant pull force to the second end of the passageway to extend the passageway and stabilize the vessel.
41. A method of attaching to an object, the method comprising resiliently deforming first and second gripping devices apart from a rest position to receive an object there between by application of an impact force with the object.