GB2490252A

GB2490252A - A waterborne vessel with a carriage assembly for docking

Info

Publication number: GB2490252A
Application number: GB1206975.3A
Authority: GB
Inventors: Edward Robertson Peter Dudson; Simon Walley
Original assignee: BMT NIGEL GEE Ltd
Current assignee: BMT NIGEL GEE Ltd
Priority date: 2011-04-20
Filing date: 2012-04-20
Publication date: 2012-10-24
Anticipated expiration: 2032-04-20
Also published as: GB201206975D0; GB201106667D0; GB2490252B

Abstract

A waterborne vessel 1 is provided with a carriage assembly at an end portion of the vessel. The carriage assembly is arranged to bear against an external structure (50, Fig 6), while a carriage 2 of the carriage assembly is mounted for movement relative to the vessel. The carriage assembly further comprises a resilient buffer 15 to counter movement of the carriage towards an opposite end of the vessel and the carriage is mounted such that it is capable of rotational movement relative to the vessel. The carriage assembly is arranged to allow access between the vessel and an external structure.

Description

WATERBORNE VESSEL

Technical Field

The present invention relates generally to waterborne vessels.

Background

When a vessel noses-up' to (ie approaches head-on) a structure, such as a quay structure or marine structure, for the purpose of allowing access to the structure from the vessel, on the vessel impacting against the structure, a significant impact force can be imparted to the structure. Such large impacts can potentially damage the structure.

We have appreciated that it would be advantageous to provide an improved vessel.

Summary

According to a first aspect of the invention there is provided a waterborne vessel provided with a carriage assembly at an end portion of the vessel and the carriage assembly arranged to bear against an external structure, a carriage of the carriage assembly mounted for movement relative to the vessel, the carriage assembly further comprising a resilient buffer to counter movement of the carriage towards an opposite end of the vessel, and the carriage arranged to allow access between the vessel and an external structure, and wherein the carriage is mounted to be capable of rotational movement relative to the vessel.

An upper surface of the carriage preferably comprises a walkway.

The carriage is preferably slidably mounted on the vessel.

The carriage preferably comprises side portions to engage with the vessel and allow for rotation of the carriage relative to the vessel.

The carriage preferably comprises an underlying surface arranged to be supported by a deck portion of the vessel.

Preferably, two underlying surfaces are provided which each define, with a respective opposing surface of the carriage, a channel, and each channel provided at a respective side of the carriage, and each channel arranged to receive a respective portion of the vessel.

The carriage assembly is preferably located at a fore portion of the vessel.

Brief description of the drawings

One embodiment of the invention will now be described, by way of example only, with reference to the following drawings in which: Figure 1 shows a perspective view of a waterborne vessel, Figure 2 shows an alternative perspective view of the waterborne vessel of Figure 1; Figure 3 shows a perspective view of the waterborne vessel of Figure 1 in an exploded condition, Figure 4 shows an alternative perspective view of the waterborne vessel of Figure 1 in an exploded condition, Figure 5 is a cross-sectional view of a carriage assembly of the waterborne vessel of Figure 1 in a neutral condition, and Figure 6 is a cross-sectional view of the carriage assembly of Figure 5 in a compressed condition.

Detailed Description

With reference to Figures 1 and 2 there is shown a waterborne vessel I which at a foremost portion thereof is provided with a carriage assembly. The carriage assembly comprises a carriage 2 which is arranged to move relative to the vessel so as to lessen the impact of the vessel on a structure.

With reference to Figure 3, the carriage 2 comprises an upper surface 3 which forms a walkway between the vessel 1 and an external structure to be accessed. The upper surface 3 is provided with railings 4. The foremost part of the carriage 2 is provided with a plurality of (rubber) fenders 5, arranged side-by-side, arranged to bear against the external structure. The front-facing portion of the carriage 2 is generally of the form of a protuberance comprising a frontmost portion 2a, flanked by angled side portions 2b. Advantageously, the protuberance is arranged to be received in a space between two upright fender structures, such as those on a foundation structure of a wind turbine. The fender structures usually enclose an access ladder, which allows personnel to access the wind turbine. In this way, the protuberance serves to locate the carriage relative to the wind turbine structure and prevent lateral movement thereof. Generally, the foremost portion of the carriage 2 is configured to be capable of engaging with a structure to be accessed, and so may be differently configured (as compared to the embodiment shown) in other embodiments to suitably engage with the structure.

Side regions of the carriage 2 comprise respective channels 6. An uppermost part of the channel 6 is defined by a support surface 7, vertically spaced-apart from a lower surface 8. Side most regions 11 and 12 of the carriage, and specifically the lateral margins of surfaces 7 and 8, are of generally curved shape. Underlying the surface 3 there is provided a stop surface 10 (as shown in Figures 5 and 6) which, as described below, is arranged to receive resilient buffers.

The carriage assembly further comprises two spaced-apart resilient buffers 15. The buffers 15 are located within a recess 30 which may be considered as a cut-out section of the deck of the vessel. Each buffer comprises a bellow structure 16 and a forward-facing plate 17. Each bellow structure comprises a tubular member made of a resilient material (such as an clastomer or fender material). Each tubular member is capable of being compressed, and once the compression force is removed, experience a restoring force to substantially return to its initial (uncompressed) condition. The plates 17 are arranged to bear against the stop surface 10.

The vessel 1 comprises support surfaces 20 of a deck portion of the vessel which are arranged to support respective surfaces 7 of the carriage 2. In this manner, the carriage is slidably mounted on the vessel. In particular, the carriage 2 is capable of sliding translational movement substantially along a longitudinal direction of the vessel (ie along a line connecting the fore and aft regions of the vessel), as shown by the double-headed arrow in Figure 2.

Operation of the vessel, and in particular the carriage 2, will now be described. The vessel 1 approaches a wind turbine structure to be accessed. The forward movement of the vessel is directed towards the fender structures of the wind turbine structure such that the protuberance can be received therebetween. On the fenders 5 contacting the fender structures of wind turbine structure a reaction force is impacted onto the carriage. The reaction force causes the carriage 2 to be urged in a rearward direction by way of sliding engagement between the surfaces 7 and the respective surfaces 20 of the vessel 1, In this way impact of the vessel on the fenders is lessened, with the shock being absorbed by the buffers 15.

Reference is made to Figure 6 which shows the vessel in a docked' condition with the fenders 5 of the carriage 2 bearing against a fender structure 50 of a wind turbine structure. As can be seen from Figure 6 the resilient bellow 16 is in a compressed condition. In order to maintain the vessel in this condition a forward thrust is applied by the propeller or other motive arrangement of the vessel, to urge the vessel forwards and against the fender structures 50. With the carriage 2 located by the fender structures 50, the curved surfaces 11 and 12 are capable of engaging with opposing structures 25 of the vessel and so allow for rotational movement of the vessel relative to the carriage 2 (caused by lateral current and/or wind acting on the vessel).

Personnel wishing to access the wind turbine from the vessel can step onto the walkway 3 of the carriage 2 and then climb the ladder of the wind turbine structure.

Once any maintenance work has been completed, and the personnel have returned to the vessel, the vessel then applies a reverse thrust to move away from the wind turbine. In so doing the force which had compressed the bellows 16 of the buffers 15 is removed, and the resilient nature of the bellows causes them to revert to the condition shown in Figure 5.

In one embodiment of the invention there is provided a force feedback arrangement which is configured to provide a measure of the force applied to the external structure (against which the carriage is bearing) by the vessel. Such an arrangement may comprise a sensor to measure the extent of displacement/travel of the carriage relative to the vessel, and the sensor comprising a reference component mounted on one of the vessel or the carriage a second component (whose position can be determined relative to the reference component) is mounted on the other of the vessel and the carriage.

The determination of the relative position of the reference component and the second component may be by way of suitable optical, mechanical or magnetic sensor apparatus. An output indicative of a measure of force is determined in relation to signals received from the sensor, calibrated such that the greater the magnitude of displacement, the larger the measure of force indicated. This information is advantageously available to the crew controlling the vessel

Claims

CLAIMS1. A waterborne vessel provided with a carriage assembly at an end portion of the vessel and the carriage assembly arranged to bear against an external structure, a carriage of the carriage assembly mounted for movement relative to the vessel, the carriage assembly further comprising a resilient buffer to counter movement of the carriage towards an opposite end of the vessel, and the carriage arranged to allow access between the vessel and an external structure, and wherein the carriage is mounted to be capable of rotational movement relative to the vessel.
2. A vessel as claimed in claim 1 in which an upper surface of the carriage comprises a walkway.
3. A vessel as claimed in claim 1 or in claim 2 in which the carriage is slidably mounted on the vessel.
4. A vessel as claimed in claim 3 in which the carriage comprises side portions to engage with the vessel and allow for rotation of the carriage relative to the vessel.
5. A vessel as claimed in any preceding claim in which the carriage comprises an underlying surface arranged to be supported by a deck portion of the vessel.
6. A vessel as claimed in claim S in which two underlying surfaces are provided which each define, with a respective opposing surface of the carriage, a channel, and each channel provided at a respective side of the carriage, and each channel arranged to receive a respective portion of the vessel,
7. A vessel as claimed in any preceding claim in which the carriage assembly is located at a fore portion of the vessel.
8. A waterborne vessel substantially as described herein with reference to the drawings.