TECHNICAL FIELD OF THE INVENTION

The invention concerns movable gangways and access bridges. More specifically, the invention concerns a gangway assembly as defined by the preamble of claim 1.

BACKGROUND OF THE INVENTION

A gangway, sometimes also referred to as an access bridge, is used for providing a bridge between two objects, and is particularly useful when one object is moving with respect to a fixed object or when two objects are moving independently of one another. Gangways are used for establishing a bridge between for example two floating objects (e.g. vessels, platforms) at sea, and between a vessel or platform and a fixed object (such as a quay or other foundation).

Different gangway designs exist, where the gangway length, number of elements and joints, etc. are adapted by designers and suppliers to accommodate customer inputs and requests. State-of-the-art gangways are moveable in several degrees of freedom, may be controlled manually or may comprise active motion compensation systems. The prior at comprises CN 110239672 A, which describes a gangway having a first gangway part rotatably connected to a slewing base, and a second gangway part telescopically connected to the first gangway part. The prior art also comprises WO 2015/009163 A1, which describes a gangway and an associated active motion compensation system.

The prior art also comprises CN 212243715 U, which describes a marine accommodation ladder device which comprises an accommodation ladder, a vertical accommodation ladder guide rail and an adjusting assembly. The adjusting assembly comprises a lifting unit and an adjusting unit, the adjusting unit comprises a swing mechanism and a pitching mechanism, the accommodation ladder is arranged on the accommodation ladder rail in a lifting manner, and the pitching mechanism is arranged on the upper end part of the accommodation ladder rail. The accommodation ladder is rotatably arranged on the rotation mechanism in the horizontal direction, and the accommodation ladder is rotatably arranged on the rotation mechanism in the vertical direction.

The prior art also comprises WO 2012/069825 A1, which describes a bridge apparatus to transfer persons between a moving structure such as a vessel and a second structure such as an offshore installation, for example, to span gaps between work boats and fixed offshore installations such as wind turbines. The bridge comprises a platform supported by a line, the platform being moveable in a vertical direction by movement, of the line, wherein the line extends in a vertical direction from the platform to a capstan, and from the capstan to a counterweight.

The prior art also comprises WO 00/15489 A1, which describes a mooring arrangement, for mooring, primarily of smaller vessels to ground-anchored or floating structures at sea, such as sea based wind-power stations, lighthouses and constructions for extracting and loading oil. The mooring arrangement comprises a connecting means, a manoeuvring member arranged at one end of the connecting means, a locking device arranged at the other end of the connecting means and a control means.

SUMMARY OF THE INVENTION

The invention is set forth and characterized in the main claim, while the dependent claims describe other characteristics of the invention.

It is thus provided a gangway assembly, comprising a main boom having a first end and a second end (13), wherein the main boom supports at least one gangway extending along the main boom, wherein the main boom is pivotally connected to a first support at a fulcrum; characterized by

- a pivoting assembly arranged below the gangway and comprising a first electric motor-and-winch assembly, a sheave assembly, and one or more first wires extending between the first electric motor-and-winch assembly and the sheave assembly,
- wherein the first electric motor-and-winch assembly is arranged in the region of the main boom second end, and the sheave assembly is arranged on the first support, or vice versa.

In one embodiment, the fulcrum is arranged at a distance from the main boom second end, and this distance is less than half the total main boom length.

The gangway assembly further comprises a second support, and the first support is a slewing base which is connected to the second support via a slewing mechanism.

In one embodiment, the gangway assembly further comprises an erect column, and the second support is slidably connected to the column via a rail and roller assembly whereby a the first support may be moved up and down on at least a portion of the column.

In one embodiment, the gangway assembly further comprises an elevator assembly comprising a rail assembly on the column, and a plurality of wheels and a second electric motor-and-winch assembly arranged on the second support below the gangway, and second wires connected to respective fixtures at an upper end of the column.

In one embodiment, the gangway assembly comprises a secondary boom connected to the main boom, telescopically extendable and retractable with respect to the main boom first end. The gangway assembly further comprises one or more sheaves arranged in the region of the free of the secondary boom, and a lifting wire arranged in said one or more sheaves and being operatively connected to a winch assembly.

In one embodiment, the gangway assembly comprises a wire positioning device movably connected to the main boom, arranged to move along the main boom, and comprising a rotatable arm having a control sheave rotatably connected to the arm free end in the direction towards the main boom free end. The arm is configured to rotate between a first position in which the control sheave is aligned with the main boom longitudinal axis and a second position in which the control sheave is not aligned with the main boom longitudinal axis. The gangway assembly further comprises a guide rail 31 arranged on the main boom and extending along the main boom longitudinal axis, and a control member arranged on the arm and movably connected to the guide rail, and wherein the guide rail comprises a deviating portion whereby moving the wire positioning device towards the main boom first end will cause the arm to move towards the second position.

BRIEF DESCRIPTION OF THE DRAWINGS

These and other characteristics of the invention will become clear from the following description of an embodiment of the invention, given as a non-restrictive example, with reference to the attached schematic drawings, wherein:

FIG. 1 is a perspective view of a first embodiment of the gangway assembly according to the invention;

FIG. 2 is a side view of the gangway assembly illustrated in FIG. 1, where a gangway element has been partly extended from the main boom;

FIG. 3 is an enlarged drawing of the area “A” in FIG. 2;

FIG. 4 is a side view of the gangway assembly illustrated in FIGS. 1 and 2, in an elevated position on a foundation column;

FIG. 5 is another side view of the gangway assembly illustrated in FIGS. 1 and 2, illustrating the gangway in three different positions in a vertical plane;

FIG. 6 is a top view of the gangway assembly illustrated in FIGS. 1 and 2, illustrating the gangway in three different positions in a horizontal plane;

FIG. 7 is a side view of the gangway assembly illustrated in FIGS. 1 and 2, in a parked, inactive, position;

FIG. 8 is a side view of a second embodiment of the gangway assembly according to the invention, showing a gangway (secondary boom) in a partly extended position and a wire positioning device connected to the main boom;

FIG. 9 is a perspective view of a part of the embodiment illustrated in FIG. 8, showing the gangway in a retracted position;

FIG. 10 corresponds to FIG. 9 but illustrates the region of the main boom first end and the wire positioning device closer to the main boom first end;

FIG. 11 is an enlarged view of the area “B” in FIG. 10;

FIG. 12 is a cross-sectional view of the main boom, illustrating a guiding interface between the wire positioning device and the main boom;

FIG. 13 is an enlarged view of the area “C” in FIG. 12;

FIG. 14 is a plan view of the underside a portion of main boom, illustrating i.a. a guide structure connected to the main boom;

FIGS. 15-17 illustrate a sequence of retrieving a crane wire by means of the wire positioning device; and

FIG. 18 corresponds to FIG. 10, but illustrates the crane wire being controlled by the wire positioning device.

DETAILED DESCRIPTION OF EMBODIMENTS OF THE INVENTION

The following description may use terms such as “horizontal”, “vertical”, “lateral”, “back and forth”, “up and down”, “upper”, “lower”, “inner”, “outer”, “forward”, “rear”, etc. These terms generally refer to the views and orientations as shown in the drawings and that are associated with a normal use of the invention. The terms are used for the reader's convenience only and shall not be limiting.

Referring initially to FIG. 1 and FIG. 2, the gangway assembly 1 according to the invention comprises in the illustrated embodiment a main boom 2 having a first end 12 and a second end 13, and the main boom is pivotally connected to a first support, here in the form of a slewing base, 4. The slewing base 4 is in turn connected to a second support, here in the form of a foundation, 5 which is slidably connected to and supported by an erect column 6. Except where specifically mentioned below; sensors, feedback systems, control units, power equipment, etc., required to operate the gangway assembly are not described in detail, as these are well known in the art.

The column 6, which may be firmly connected to a supporting structure (not shown) such as a ship or other ocean-going vessel, comprises an opening 8 that provides access to a personnel elevator or stairway (not shown) inside the column. The personnel elevator or stairway may extend down to multiple decks on a ship or other vessel. An access platform 9, which is fixed to (and on top of) the slewing base 4, provides access between the opening 8 and a gangway 10 which is connected to—and extends along—the upper side of the main boom 2. An extendable gangway 3 is connected to the main boom 2 and gangway 10, and may be extended and retracted telescopically from the main boom first end 12 as indicated by the double arrow T. The extension and retraction of the extendable gangway 3 is powered and controlled by electric motors (not shown). A hook 22 is supported by lifting wire 36 running over a primary sheave 26 on the free end of the extendable gangway 3, connected to and operated by an electric motor and winch (not shown in FIGS. 1 and 2). The hook 22 may be used to handle cargo and other objects, and the extendable gangway 3 may be moved back and forth as required. In the following, the extendable gangway 3 may therefore also be referred to as a secondary boom 3.

An assembly of ladders and platforms 7, arranged on the outside of the column 6, provides access to the top of the column and to the access platform.

Referring additionally to FIG. 3, the gangway assembly 1 comprises an elevator assembly 24, whereby the foundation 5 (which carries the slewing base 4 and main boom 2) may be moved up and down the column 6, as indicated by the double arrow V in FIG. 1. In the illustrated embodiment, the elevator assembly 24 comprises a rail assembly 21 on the column 6 and a plurality of wheels 20 on the foundation 5, an electric motor-and-winch assembly 17, and wires 18 connected to respective fixtures 19 at an upper end of the column. Such elevator assembly is generally known in the art.

The slewing base 4 is rotatably connected to the foundation 5 via slewing mechanism 11 and is powered and controlled by an electric motor (not shown). The slewing base, main boom and gangways may thus be rotated in the xz plane, as indicated by the arrows S in FIG. 1 and FIG. 6, in a manner known in the art.

The main boom 2 is rotatably supported by the first support (in the illustrated embodiment: slewing base) 4 at a fulcrum schematically indicated in FIG. 3 by reference number 23. The fulcrum 23 is arranged at a distance d from the main boom second end 13, and this distance d is less than half the total main boom length. Such pivot support is per se well known in the art. In the illustrated embodiment, the main boom second end 13 extends towards the column 6. The gangway assembly comprises a pivoting assembly 25, whereby the main boom 2 and gangways may be rotated (pivoted) about the fulcrum 23, in the xy plane, as indicated by the double arrow P in FIG. 2 and FIG. 5. In the illustrated embodiment, the pivoting assembly 25 comprises a motor-and-winch assembly 14 in a region of the main boom second end 13, a sheave assembly 16 on the first support 4, and one or more wires 15 extending between the motor-and-winch assembly 14 and the sheave assembly 16. The motor in the motor-and-winch assembly 14 is an electric motor. A reversed arrangement is conceivable, i.e. where the motor-and-winch assembly 14 is arranged on the first support 4 and the sheave assembly 16 is arranged in a region of the main boom second end 13.

One significant aspect of the gangway assembly is that the electric motor-and-winch assembly 17 in the elevator assembly 24 is arranged below the gangways 3, 10. This feature allows the gangways (and access platform 9) to be elevated above the column 6, as illustrated in FIG. 4, such that there are no tower or other element extending above the gangways. This is particularly advantageous when operating underneath structures, for example when providing access between a ship and an offshore wind power plant. FIG. 6 illustrates how the boom 2 (and thus the gangway 10) may be rotated such that the main boom and gangway in fact are positioned above the tower 6 when elevated above the tower as shown in FIG. 4. The elevator assembly 24 also provides for a stepless translation along the column, and the electric motor provides for rapid response and precise control.

Another significant aspect of the gangway assembly is that the pivoting assembly 25 is arranged below the access platform and gangways, whereby personnel are not exposed to moving parts. The electric motor-and-winch assembly 14 also provides for instantaneous and stepless response when it is necessary to compensate for main boom movements. In a dynamic situation, for example when the gangway assembly is arranged on a ship and is in operation to interconnect the ship with a stationary or moving structure, the main boom is moving in the xy plane due to relative movements between the ship and the structure. These movements may cause alternating tension and relaxation in the pivoting wires 15. The electric motor-and-winch assembly 14 will be able to react instantaneously in order to compensate for the main boom movements and maintain appropriate tension in the pivoting wires 15 at all times, and thus preventing slack in the pivoting wires.

A second embodiment of the gangway assembly according to the invention will now be described with reference to FIGS. 8 to 18. Unless otherwise noted, the features described above with reference to FIGS. 1 to 7 shall apply also to this second embodiment.

Referring initially to FIG. 8, it will be noted that the pivoting assembly 25 in this embodiment comprises a reversed arrangement compared to that of the first embodiment, in that the motor-and-winch assembly 14 is arranged on the first support (slewing base) 4 and the sheave assembly 16 is arranged in a region of the main boom second end 13. FIG. 8 illustrates the extendable gangway (also referred to as the secondary boom) 3 in a partly extended position. The primary sheave 26 is illustrated, but the associated hook 22 and lifting wire 36 (see FIG. 1) have been omitted in FIGS. 1 to 15.

Referring additionally to FIGS. 9 to 11, the gangway assembly according to the second embodiment of the invention comprises a wire positioning device 29 which is movably connected to the main boom 2. The wire positioning device 29, in the following also referred to as a trolley, is connected to a rail assembly 40 on the main boom 2 via a lug-and-wheel assembly 33, and may thus travel back and forth along the main boom 2. The trolley 29 is movable along the main boom by an electric motor-and-winch assembly 30 and a translation sheave 28 arranged on opposite sides of the trolley. A trolley actuation wire 38 is running between the motor-and-winch assembly 30, the translation sheave 28, and a connection member 39 on the trolley, whereby operation of the motor-and-winch assembly 30 moves the trolley along the main boom, in a manner that per se in known in the art. It should be noted that cables, wires, etc. to control the assembly are not shown in all of the drawings.

The wire positioning device (trolley) 29 comprises a framework to which an arm 34 is rotatably connected via a pivot connection 35. A sheave 27, hereinafter referred to as a control sheave, is rotatably connected to the arm 34 free end in the direction towards the main boom free end 12. The control sheave 27 is arranged in a vertical plane, as is the primary sheave 26. Referring to FIGS. 15 and 16, the arm 34 is configured to rotate between a first position (hereinafter referred to as a closed position) in which the control sheave 27 is aligned with the main boom longitudinal axis (FIG. 15) and a second position (hereinafter referred to as an open position) in which the control sheave 27 is not aligned with the main boom longitudinal axis (FIG. 16). Reference number 32 denotes an intermediate sheave on the free end of the main boom 2; the purpose of which is to carry the lifting wire 36 between the primary sheave 26 and the control sheave 27.

The arm 34 is thus operable to retrieve the lifting wire 36 and to control the lifting wire exit position along the main boom, as shown in FIG. 18. The lifting wire 36 is retrieved by moving the trolley 29 towards the main boom 2 free end, with the arm 34 in an open position, until the control sheave 27 is beyond the lifting wire 36 (see FIG. 16). At this point, the arm 34 is moved to the closed position (see FIG. 17). Moving the trolley 29 away from the main boom first end will thus cause the lifting wire 36 to be captured and controlled by the control sheave 27. When the lifting wire 36 is running through the control sheave 27, the exit position is controllable by moving the trolley 29 back and forth along the main boom, as described above.

The trolley 29 and trolley arm 34 may be controlled manually, based on visual position observations, or by a control device (not shown) based on sensor data, or a combination of both. The trolley arm 34 may be operated by a motor, for example an electric motor (not shown) arranged on the trolley 29.

However, the present invention comprises a mechanical and automatic trolley arm control assembly, which removes the need for sensors or motors on the trolley or the main boom first end. Referring in particular to FIGS. 13 and 14, the trolley arm control assembly comprises a guide rail 31 arranged on the main boom 2 and extending along the main boom longitudinal axis, and a control member 37 arranged on the arm 34. In the illustrated embodiment, the control member 37 is arranged on the opposite side of the pivot connection 35 from the control sheave 27. As is clearly seen in FIG. 13, the control member 37 comprises an interface portion (here: a slit) which is movably and mechanically connected to the guide rail 31. Referring to FIG. 14, the guide rail 31 comprises a deviating portion 31′, i.e. a portion of the guide rail 31 that deviates from the main boom longitudinal axis. Therefore, moving the trolley towards the main boom first end will cause the trolley arm 34 to move towards the open position, as illustrated in FIG. 16.

FIGS. 15 to 18 illustrate a sequence for retrieving the lifting wire 36 by means of the wire positioning device (trolley) 29. The secondary boom 3 is initially extended a distance such that the lifting wire 36 is arranged a distance in front of the main boom first end 12. The trolley 29 is then moved towards the main boom first end, until the control sheave 27 is an open position (FIG. 15). The secondary boom 3 is then retracted such that the lifting wire 36 is arranged between the control sheave 27 and the arm pivot connection 35 (FIGS. 16). Thus, when the trolley 29 is moved away from the main boom first end 12, the lifting wire 36 is carried with the control sheave 27 (FIG. 17 and FIG. 18). With the lifting wire connected to and controlled by the trolley 29, the secondary boom 2 with the extendable gangway may be operated independently of the crane function, i.e. the secondary boom 2 may be moved back and forth while the trolley 29 may be kept stationary or moved as required to perform a crane function. It will be understood that a reversed sequence will release the lifting wire from the control sheave.

As all actuators in the gangway assembly comprise electric motors, stepless motion compensation in all dimensions is accomplished rapidly. The electric motors therefore offer a significant improvement over the hydraulic actuators of the prior art. The gangway assembly is all electrically powered, with no need for hydraulic actuators and associated equipment. The electric motors and associated control systems allow for an improved three-dimensional control of the gangway assembly, with more accurate response times than traditional hydraulic actuators. As such, the use of electric motors facilitates the use of wires and winches to control the main boom movement, without compromising on performance or reliability.