NL1024196C2 - Boat with telescopic gangway securable to offshore mast, has gangway secured to grip bar using hooked arm and locking device - Google Patents

Abstract

The coupling device (10) for securing the gangway (4) to the mast (1) comprises a hooked arm for securing around a grip bar (11) protruding from the mast, in addition to a locking device (22) for cooperating with the hooked arm in the closed position so that the coupling device extends completely around the grip bar. The gangway is attached to the boat (2) at one end and can be moved in the horizontal and vertical direction. The coupling device is provided at the free end of the gangway and can be secured to a substantially vertical grip bar protruding from the mast.

Description

Short description: Vessel equipped with a walkway that can be connected to an offshore pile body.

The invention relates to a vessel provided with a walkway connectable to an offshore pile body according to the preamble of claim 1.

Such a vessel is known from WO 02/20343. Herein the vessel is provided with a telescopic extendable walkway mounted on the vessel 10 about two axes. The walkway comprises at its free end a coupling device which is adapted to be coupled to a substantially vertically oriented gripping rod which is provided on an offshore pile body. In operation, the vessel is maneuvered to a suitable starting position with respect to the vertical gripper bar. Subsequently, the footbridge is directed by a suitable pivoting movement at the middle part of the gripper bar and the walkway is extended until the coupling device is accurately positioned in front of the gripper bar. Subsequently, two hydraulically operated coupling claws of the coupling device that are pivotable towards each other from an opened position are closed. The closure is such that the coupling device then still has the freedom to move along the gripping rod in the coupling phase. Upon reaching the desired coupling position on the gripper bar, the coupling claws are moved further towards each other in order to clamp the gripper bar tightly and to fix the position thereon.

A disadvantage here is that coupling is sometimes somewhat difficult, especially in heavy weather. Furthermore, in the event of a failure of the hydraulic circuit, disconnection can take place immediately, because the coupling claws are no longer held in a closed position. This can even result in the free end of the walkway falling down while people are on it. If the coupling claws partially release, similar problems arise because the coupling device is suddenly given the freedom to slide down along the gripper bar and thereby carry the walkway into its "fall". In addition, during the coupling phase there must be an accurate tuning of the closing of the coupling claws with the release of other degrees of freedom of the walkway, in order to prevent damage to the vessel.

The present invention has for its object to at least partially obviate the above-mentioned H disadvantages, or to provide a usable alternative. In particular, it is an object of the invention to provide a user-friendly reliable coupling between a vessel and an offshore pole body that also offers a high degree of safety in the event of failure of power systems such as a hydraulic circuit.

This object is achieved according to the invention by a vessel I according to claim 1. The coupling device herein comprises a hook arm and a locking element movable between an open and closed position. During the coupling phase, the hook arm serves to grasp behind the grip bar by means of suitable maneuvering of the vessel and the walkway. This then advantageously immediately establishes a certain degree of coupling, which coupling has the freedom to slide up and down over the gripper bar. The locking element is adapted to, in the closed position, confine the gripping rod together with the hook arm. During the coupling phase, and in particular in the closed position of the locking element, the coupling between the coupling device and the gripper bar is no longer dependent on hydraulic systems or other energizing systems. This increases safety. The hook arm enables quick and reliable coupling, without thereby running the risk of damage to parts of the vessel during the coupling phase, for example due to late release of other degrees of freedom of the walkway.

In a special embodiment, the hook arm comprises two parts which are rotatably connected to each other around a substantially vertical pivot axis. Between the two hook arm parts, biasing means are provided for gripping the gripping rod clampingly under bias. This provides the possibility of obtaining an automatically upward and / or downwardly limited coupling in conjunction with a specially adapted gripper rod on an offshore pile body. The gripping rod specially adapted thereto herein comprises a guide part and a coupling part, the cross-section of the guide part being larger than that of the coupling part. During the coupling phase the hook arm is hooked around the guide part of the gripper bar, whereafter the two hook arm parts come to rest against the guide part under bias. If the hook arm is subsequently shifted over the guide part 5 in the direction of the coupling part, then the pretension will automatically ensure that, when the coupling part is reached, the two hook arm parts move towards a more closed position relative to each other in order to lower the smaller cross-section of the coupling part. The hook arm is then fixed in position substantially slidably on the coupling part in that the larger cross-section of the guide part forms a boundary. During shifting, the locking element is preferably in the closed position, but can optionally also be moved to the closed position only after the coupling part has been reached.

Further preferred embodiments of the invention are defined in the subclaims.

The invention also relates to an assembly of an offshore pile body with a vessel according to one of the claims 7-13, as well as to a method according to claim 14.

The invention will be further elucidated with reference to the drawing, in which:

FIG. 1 is a schematic perspective view of an embodiment of an offshore pile body and a vessel coupled thereto;

FIG. 2 is an enlarged view of the coupling device in FIG. 1;

FIG. 3 is a view corresponding to FIG. 1 of the pole body.

In Fig. 1, an offshore pile body is indicated in its entirety by reference numeral 1. The pile body 1, also referred to as monopole, can for instance be a transmission tower, the support column of a windmill or a support leg of an offshore platform.

Reference numeral 2 denotes a vessel on which personnel can be brought in that the pile body 1 must enter to perform maintenance work thereon. The pile body 1 is provided with a platform 3 protruding therefrom, which provides further access to the pile body 1 or a construction connected thereto.

In order to enable a safe "transfer" of the personnel from I the vessel 2 to the landing 3 on the pole body 1 and vice versa at any time between low and high tide and in rough weather conditions use is made of a retractable and extendable footbridge 4. The one part 4a thereof is pivotally connected about a horizontal axis a I to a boarding / dismounting platform 5 on the upper end I of a column 6, which by means of a slewing ring 7 is rotatably mounted on the deck of the vessel 2 about a standing shaft b.

Between the pivot column 6 and a point on the underside of the walkway part 4a a hydraulic piston-cylinder device 8a extends, which can effect an adjustment of the angle of inclination of the walkway 4.

The second in-and-extendable bridge part 4b, by means of a hydraulic piston-cylinder device 8b, is connected at its free end to a coupling device 10.

The coupling device 10 serves to establish, near the platform 3, a connection to a vertically oriented gripping rod 11 on the pile body 1.

As can be seen in Fig. 2, the coupling device 10 comprises a hook arm I20, which here is made up of two parts rotatably connected to each other around a vertical pivot axis 16, namely a frame part I 15a and a turning part 15b. Together, the frame part 15a and the turning part 15b define a U-shape, the legs of which are larger than the cross-section of the gripping rod 11. Between the frame part 15a and the H-turning part 15b, biasing means 18 are provided, which here are formed by a hydraulic piston-cylinder device. The turning part 15b is provided at its free end with an H insert chamfer 20, to facilitate hooking the hook arm 15 around the gripper bar 11, in particular to some extent against the H 30 action of the biasing means 18.

Mounted on the frame part 15a is a locking element 22 which can be tilted about a pivot axis 21. A hydraulic piston-cylinder device 23 is provided for moving the locking element 22 between an open and a closed position. This can be controlled from I the vessel or, for example, be activated automatically if a detector I (not shown) provided in the hook arm 15 detects the presence of the gripper bar 11H therein.

5

The hook arm 15 is rotatably connected around the horizontal pivot axis 25 with the walkway part 4b. The hook arm 15 can be adjusted by means of a hydraulic piston-cylinder device 26 (see Fig. 1) as desired in different angular positions relative to the walkway 4, but can also be fixed in a certain angular position depending on the area of application. The latter is possible, for example, in areas where the tidal difference is small and the height of the intended coupling position on the pole body is substantially constant.

In the hook arm 15 and on the locking element 22, damping bodies 27 are provided, which here are formed by rubber buffer blocks. These serve to make hooking run more smoothly during the coupling phase and to absorb sudden movements during operation. A damping body 28 is also provided on the underside of the hook arm 15 (see Fig. 1), the operation of which will be explained below.

The gripping rod 11 provided on the pile body 1 extends upwards from the platform 3, and is connected at its upper end to a support beam 30. The gripping rod 11 is provided with a coupling part 31 and a guide part 32 located above it. Cam bodies 33 extending in the longitudinal direction thereof are provided on the guide part 32. The cam bodies 33 provide the guide part 32 with a larger cross section than the coupling part 31.

The coupling part 31 has a height that substantially corresponds to the height of the hook arm 15.

A possible method of coupling now works as follows: In the case of non-use, the walkway 4 is oriented along the longitudinal axis of the vessel 2 and the walkway 4 rests on a support bracket 35. Thus, the vessel 2 sails with one or more fitters to the pole body. 1 for 30 performing work thereon, such as eliminating malfunctions. The vessel 2 is brought into position in the vicinity of the pile body 1 in accordance with the prevailing wave / wind direction. The walkway 4 is then lifted from the support 35 by operation of the hydraulic piston-cylinder device 8a and brought to a position opposite the gripper rod 11 by hydraulic actuation of the turntable 7 and of the hydraulic piston-cylinder device 8b. The walkway 4 together with the coupling device 10 is hereby maneuvered such that the 6 hook arm 15 hooks behind the gripping rod 11, preferably substantially in the middle of the guide part 32 thereof. The locking element 22 is then folded down, as a result of which the gripping rod 11 is received in a form-fitting manner by the coupling device 10.

The hydraulic piston-cylinder device 8b is then made pressureless, as a result of which the walkway 4 can slide in and out freely, and the distance from the vessel 2 to the pile body 1 can and may vary. The footbridge 4 is maneuvered by operating the hydraulic piston-cylinder device 8a such that the coupling device 10 slides down the guide part 32. The biasing means 18 here press the pivoting part 15b of the hook arm 15 against the frame part 15a with a small force. As soon as the coupling part 31 is reached during sliding downwards, the pivot part 15b 15 will be able to rotate further towards the frame part 15a as a result of the above-mentioned bias, until the smaller cross-section of the coupling part 31 is tightly encircled. The platform 3 advantageously forms a limiting means for the coupling device 10 during sliding downwards. The damping body 28 provided on the underside of the hook arm 15 hereby ensures that the coupling device 10 does not hit the platform 3 with a blow. Thus, sliding down of the coupling device 10 can be carried out at a relatively high speed. After the intended coupling position has been reached, the hydraulic piston-cylinder device 8a can also be made pressureless, so that from that moment on, vertical movements of the vessel 2 can be absorbed.

In a variant, both hydraulic piston-cylinder devices 8 are already fully or partially depressurized after the coupling device 10 is coupled to the guide part 32. This results in the coupling device 10 automatically moving to the intended coupling position at the intended coupling position under the influence of gravity. coupling part 31 will lower and automatically lock up and down bounded there. The hydraulic piston-cylinder devices 8 can also remain energized in such a way that, in the event of an emergency, the walkway 4 maintains a slight tendency towards the top, so that any people still on the walkway 4 do not fall directly into the water.

7

The construction with the hook arm 15 and the down and up limitation ensures that in the event of a failure of the hydraulic circuit, the walkway 4 remains in its intended coupling position, that is to say on the coupling part 31. Downwards the coupling device 10 rests on the platform 3, upwards the coupling device is bounded by the cam bodies 33, while the hook arm 15 and the locking element 22 continue to enclose the coupling part 31 of the gripping rod 11.

The transfer of personnel via the footbridge 4 to and from the platform 3 can now be done easily and safely.

In addition to the embodiment shown, many variants are possible. Other types of excitation systems are thus also possible, for example an adjustable suspension support for the footbridge part 4a. The hook arm is preferably provided with a shear pin construction which ensures that upon reaching too great a load on the coupling device, the pivot part of the hook arm can fold open to an open position relative to the frame part of the hook arm. Instead of automatically operating biasing means, controllable movement means can also be provided between the turning part 20 and the frame part of the hook arm. In addition, a different type of coupling device, with or without biasing means, can be used in combination with the characteristic of the gripping rod with the guide part and the coupling part.

The invention thus provides a constructively simple and very safe coupling system between a vessel and an offshore pile body. This means that significant time gains can be achieved and action can also be taken in the event of a disaster under severe weather conditions.

30 1 n o a 1 o p

Claims (14)

1. Vessel provided with a telescopic extendable walkway (4) which can be coupled to an offshore pile body (1), said walkway 5 (4) movable on the vessel (2) with one end about a horizontal and a vertical axis (a and b respectively) is mounted and carries at its free end a coupling device (10) which is adapted to grip a substantially vertically oriented gripping rod (11) projecting from the pile body (1), characterized in that the coupling device (10) includes hook arm (15) for gripping behind gripping rod (11) during mounting, as well as a locking element (22) movable between an open position and a closed position for locking in between the hook position (15) together with the hook arm (15) the grab bar (11). 2. Vessel as claimed in claim 1, wherein the hook arm (15) comprises two parts (15a, 15b) which are rotatably connected to each other around a substantially vertical pivot axis (16), wherein biasing means (18) are provided between the two parts causing the gripping rod (11) to grip under pretension. 3. Vessel according to claim 1 or 2, wherein the locking element (22) is movably mounted on a coupling device (10) around a substantially horizontal pivot axis (21). 4. Vessel as claimed in any of the foregoing claims, wherein the hook arm (15) and, if desired, also the locking element (22) are provided with damping bodies (27) which are intended to abut against the gripping rod (11) of the pole body (11) 1). 5. Vessel according to one of the preceding claims, wherein the hook arm (15) comprises at the bottom a damping body (28) which is intended to come into contact with a limiting means (3) provided on the gripper bar (11). Vessel according to one of the preceding claims, wherein the hook arm (15) defines a U-shape, the legs of which are larger or equal to the cross-section of the gripper bar (11). An assembly of an offshore pile body (1) comprising a substantially vertically oriented gripping rod (11) projecting from the pile body (1), with a vessel (2) comprising a telescopic extendable walkway (4) that can be coupled to the pile body (1) , which walkway (4) is movably mounted on the vessel (2) with one end about a horizontal and a vertical axis (a and b) and carries at its free end a coupling device (10) which is adapted for gripping the gripping rod (11), characterized in that the coupling device (10) is arranged for clampingly gripping the gripping rod (11) during the coupling phase, and in that the gripping rod (11) comprises a guide part (32) and a coupling part (11) 31), wherein the cross section of the guide part (32) is larger than the cross section of the coupling part (31) to form a boundary for the coupling device (10) if it engages the coupling part (31). Assembly according to claim 7, wherein the gripping rod (11) is provided at the location of the guide part (32) with at least one longitudinally extending cam body (33). 25 Assembly according to claim 8 or 9, wherein the coupling part (31) is located under the guide part (32). 10. Assembly as claimed in claim 9, wherein the coupling part (31) is bounded at the bottom by limiting means (3). 11. Assembly as claimed in claim 10, wherein the limiting means (3) connect the gripping rod (11) to the pole body (1), and in particular form a platform from which the gripping rod (11) extends upwards, which platform is provided on the pole body (1) and access to the pole body (1) provided for personnel. 1 n? .4 1 S o An assembly according to claim 10 or 11 / wherein a damping body (28) is provided on the top side of the limiting means (3) or on the bottom side of the coupling device (10). Assembly according to any of claims 7-12, wherein the coupling device (10) comprises a hook arm (15) for gripping behind the gripping rod (11) during hooking, as well as a locking element movable between an open position and a closed position ( 22) for locking the gripper bar (11) between them in the closed position together with the hook arm (15). Method for coupling a vessel (2) to an offshore pile body (1) of the assembly according to one of claims 7-13.