Classifications

• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B63—SHIPS OR OTHER WATERBORNE VESSELS; RELATED EQUIPMENT
  • B63B—SHIPS OR OTHER WATERBORNE VESSELS; EQUIPMENT FOR SHIPPING 
  • B63B27/00—Arrangement of ship-based loading or unloading equipment for cargo or passengers
  • B63B27/18—Arrangement of ship-based loading or unloading equipment for cargo or passengers of cableways, e.g. with breeches-buoys

Definitions

• the present invention relates to a transfer system comprising a transfer holder.
• a transfer system comprising a transfer holder.
• such a transfer system is used at sea where people and/or goods have to be moved from a vessel to a maritime structure using a transfer holder.
• a telescopic gangway is used which is mounted on a structure which compensates for the waves, as a result of which the free end thereof should, in theory, be stationary with respect to the seafloor.
• Such a system is particularly complicated and, in addition, can only compensate for limited wave action, as a result of which it cannot be used with relatively high waves.
• a cable is provided between the vessel and the maritime object and the transfer holder is moved along the cable using a guide. In principle, this can be carried out at relatively high waves, but it is very uncomfortable when people have to be transferred.
• it has to be configured in such a manner that the most essential components of such a transfer system are present on a vessel in any case.
• it has to be possible to transfer significant weights, such as, for example, weights of 1 ton and more.
• This object is achieved with an above-described transfer system by the fact that it comprises first, second and third cables connected thereto, wherein said third cable makes an angle of more than 30° with said first and second cable.
• a transfer system of this type is preferably used in combination with a vessel and preferably forms part of an assembly consisting of vessel, maritime structure and the transfer system.
• the vessel has two masts which can be folded down according to a preferred embodiment of the invention and can be positioned
• guy ropes are preferably situated on opposite longitudinal sides of the vessel.
• the transfer holder By suspending the transfer holder between these masts with the aid of the first and second cable, the transfer holder in principle moves concomitantly with the movement of the vessel, as long as the third cable is inoperative. Lateral swinging of the transfer holder is prevented.
• the ship's hull is assumed to be elongate and lateral swinging is understood to mean the rolling about the longitudinal axis thereof. If a vessel, for example a platform, catamaran or the like, with different length and/or width dimensions is used, the positioning of the masts will be adjusted accordingly.
• the transfer holder will follow the movement of the maritime structure or, in the case of a maritime structure which is fixed with respect to the seafloor, will not move with respect to the seafloor.
• a gradual transition will occur from the movement of the vessel which is conveyed to the transfer holder to the movement (or lack of movement) of the maritime structure. This occurs without any lateral swinging of the transfer holder taking place.
• the easing of the first and second cable and the return movement thereof preferably takes place by means of winches fitted to the vessel.
• a common winch can be used to control the first and second cable, but it is also possible to use two separate winches for in each case each first and second cable.
• the third cable may be controlled either by means of a winch on the maritime structure or a winch on the transfer holder. If the transfer system is configured to be as autonomous as possible, that is to say if as many of the components as possible are positioned on the vessel which delivers the goods and ferries people across, the third winch will be present in the transfer holder so that it is only necessary to attach a third or fourth cable to the transfer holder and/or to the maritime structure, respectively.
• power has to be provided to this winch on the transfer holder which may be supplied by either a power source (battery) in the transfer holder, preferably on the bottom side, or by providing power via the first and/or second cable.
• a power source battery
• a combination of the two which has the advantage of improving reliability and enabling the battery to be used as an additional booster during high loads, when the winch pulls the transfer holder vertically upwards towards the maritime structure.
• the path of the transfer holder between preferably the rear side of the vessel and the maritime structure may be any conceivable path, according to a particular embodiment of the invention, this path is brought about in such a manner, by controlling the length of the first, second and third cables, that the transfer holder, during a first phase, moves from the vessel according to a substantially horizontal path at a height which is substantially equal to the height of the afterdeck of the vessel in the direction of the maritime structure. Only in the final stage of the path is the transfer holder moved upwards in the direction of the landing site on the maritime structure. This minimizes lateral swinging.
• the landing site on the maritime structure is assumed to be situated in a higher position than the (point of departure of the) ship.
• the angle between the various cables is such that maximum stability is achieved.
• the angle between the first and second cables is preferably greater than 30°. Said angle is measured if the transfer holder is situated on the vessel and the masts are in the upright position. It will be understood that if the transfer holder is moved to a maritime structure across a significant distance, this angle becomes smaller, which, on the one hand, reduces the stabilizing effect, but, on the other hand, also reduces the need for such stabilization due to the larger distance from the vessel, thus still making optimum transfer of the transfer holder possible.
• the angle between the first cable and the third cable or the second cable and third cable, respectively is greater and is preferably more than 60°.
• the masts can be positioned (rotated) in various positions, i.e. horizontal to the deck (0°), obliquely upwards directed inwards (90° with respect to the deck's longitudinal axis), perpendicularly upwards (90° with respect to the deck's longitudinal axis) and obliquely upwards directed outwards (120° with respect to the deck's longitudinal axis).
• the guy ropes In the outwardly directed position, the guy ropes are taut and carry in the length direction of the vessel.
• the masts can be positioned to lift/move the transfer holder from the deck from a controlled boarding/disembarking position and subsequently, the masts can move to the outwardly directed position, following which the third cable is pulled.
• this outwardly directed position it is possible to position this outwardly directed position in such a way that the two mast ends protrude behind the ship.
• a frame generally referred to as A frame
• an arresting cable is provided between the two masts at such a height that this arresting cable touches the first and second cable and/or the transfer holder.
• the first and second cable and/or the transfer holder will not touch this arresting cable if the masts are in the outwardly directed position and the longitudinal movement will be determined by the third cable.
• the first and second cable and/or the transfer holder will touch this arresting cable and the longitudinal movement will be inhibited by this arresting cable.
• the longitudinal movement is determined completely by the arresting cable and the transfer holder will be supported both in the transverse direction, by the first and second cable, and in the longitudinal direction, by the arresting cable.
• This arresting cable may be provided with means for absorbing energy by means of dampers and/or resilient energy.
• the masts are placed in such a manner that, in the perpendicular position with respect to the length direction of the vessel, they are spaced apart in the width direction from the vessel deck upwards.
• the present invention also relates to a method for transferring objects from a vessel to a maritime structure and vice versa by displacing a transfer holder between said vessel and said maritime structure, which transfer holder comprises first, second and third cables, wherein the first and second cables are connected to the vessel via a first and second mast and the third cable is connected to the maritime structure, wherein said displacement is achieved by pulling in said third cable when easing said first and second cables and vice versa.
• the maritime structure may comprise a further vessel, such as a ship.
• this further vessel may be provided with the same transfer system as described above. This makes it possible to goods or people between two vessels moving on the surface of the sea.
• the transfer holder is connected to the first ship in the above-described manner by two cables and is, in addition, connected to the other vessel by two cables. In this case, it is possible to use all of the above-described variants.
• Fig. 1 shows a vessel and a maritime structure
• Fig. 2 shows the vessel with a transfer holder which is ready to start and a maritime structure
• Fig. 3a shows the first phase of moving the transfer holder from the vessel to the maritime structure
• Fig. 3b shows how the transfer holder moves away from the vessel
• Fig. 3c shows how the transfer holder is initially pulled in from the maritime structure
• Fig. 3d shows a view onto the afterdeck of a situation according to 3c;
• Figs. 4-6 show the subsequent phases of transferring the transfer holder to the maritime structure
• Fig. 7 shows a rear view of a variant of the invention with an inclined vessel.
• the transfer of a transfer holder from a vessel to a maritime structure will be described. It will be understood that the return movement is also covered by the present invention and is carried out substantially in the same way, but obviously adapted to the direction of movement which is being carried out at that point in time.
• the maritime structure will be described as a part which is fixedly connected to the seafloor, but it will be understood that the maritime structure may comprise any structure, such as another vessel which moves to and fro with the waves in the same or in a different way.
• reference numeral 1 denotes a vessel on which two folded-down masts, i.e. first mast 4 and second mast 5, are situated near the longitudinal sides thereof, as is illustrated in Fig. I .
• First winch 15 and second winch 14 are fitted near the masts 4 and 5.
• reference numeral 2 denotes a maritime structure, such as an island on which a wind turbine is installed. The latter requires maintenance and to this end, both parts and people have to be transferred from the vessel 1 to the island 2 and vice versa.
• a buoy 17 is attached to the maritime structure via a cable. Obviously, the vessel will be positioned in an optimum manner with respect to the prevailing sea/wind. That is to say that either the bow or the stern is positioned in the direction of the waves.
• Fig. 2 diagrammatically shows how this transfer movement takes place.
• the masts 4 and 5 are brought to a more vertical position and, optionally, supported by guy ropes.
• the transfer holder 7 is placed on the afterdeck of the vessel 1 and first cable 9 is attached to the top side of the transfer holder and extends towards the top end of the first mast 4 and is connected to the first winch 15.
• the second cable 10 is also connected to the top side of the transfer holder 7 and extends to the top side of the second mast 5 and is connected to the second winch 14. If they are configured as two separate winches, the winches 14 and 15 can be driven by a single synchronized control mechanism.
• the transfer holder 7 is enclosed by an arresting structure, the shape of which can be seen in Figs. 2 and 3. It is depicted diagrammatically and is denoted by reference numeral 20.
• an arresting cable 21 is fitted between the masts 4 and 5 and provides support.
• a third cable 1 1 is connected to the island 2.
• Island 2 is provided with an opening 12 and a trestle 22 which is arranged above the latter and to which the third cable 11 is attached.
• the third cable can be controlled by a third winch which is situated either near this trestle 22, but is preferably arranged near the transfer holder 7 in the embodiment illustrated here.
• the third cable can be picked up easily by the vessel by means of a messenger line or a buoy 17 which is situated at the bottom of the island.
• the masts 4 and 5 are raised further, as a result of which the transfer holder 7 moves out of the arresting device 20 and moves across the deck between the masts 4 and 5 at a small distance above it and is supported by the arresting cable 21.
• cable 11 is not yet operational, as is shown in Fig. 3a.
• the masts 4 and 5 are moved further to a position in which the transfer holder 7 is situated beyond the afterdeck of the vessel, as is shown in Fig. 3b.
• This is a more or less safe situation which can be achieved without having to tension the third cable 1 1 , which means that the position of the vessel 1 with respect to the island 2 is not yet critical at that point in time.
• the third winch 13 for the third cable which is preferably present in the transfer holder may be operated either by means of a battery which is present therein or (in combination with) by a power supply. This power supply may be achieved, for example, by means of the first and second cable. From this point in time, cable 11 is tensioned, resulting in the situation as illustrated in Fig. 3c.
• Fig. 3d is a top view in which a is the angle between the first and second cable, ⁇ is the angle between the first cable 9 and the fourth cable 12 and angle ⁇ is the angle between the second cable 10 and the third cable 11. Said angle ⁇ is preferably greater than 60° and more particularly greater than 120°.
• Fig. 3d shows a top view of this situation.
• the transfer holder 7 Starting from the position illustrated in Fig. 3c, by pulling in the third cable and by easing the first and second cables, the transfer holder 7 describes a path which is designated by reference numeral 16 and which comprises a first horizontal part, followed by a vertical part, as is illustrated in Fig. 4.
• the transfer holder 7 is prevented from carrying out a swinging to-and-fro movement which is greater than the swinging movement of the amplitude of the vessel when people and goods are being transferred and the vessel is rolling.
• the transfer holder 7 is kept at as low a level as possible, that is to say as close as possible to the rolling axis of the vessel, movement of the transfer holder will be relatively limited or will even be zero.
• a to-and-fro swinging is prevented between the vessel and the maritime structure.
• Fig. 7 shows a rear view of a variant of the way in which the transfer holder is attached to the first cable 9 and second cable 10 in the situation in which the vessel is tilted significantly about its longitudinal axis. It can be seen that the transfer holder hardly changes position as a result of this tilting movement. This is supported by the fact that a branch cable 23 providing further stabilization is fitted near the attachment of cable 9 and cable 10, respectively, on the transfer holder.
• the present invention it is possible to transfer the transfer holder from the vessel to the maritime structure using parts which are known in the prior art and without technical complications. In this case, it is possible to control the various winches from the vessel, from the transfer holder or from the island 2. It is also possible to control the third and fourth cable from the island and the transfer holder, respectively, while the first and second cable are being controlled from a different position, for example from the rear of the vessel.
• a maritime structure it is possible for a maritime structure to be another vessel.
• the present invention is particularly useful if the other vessel is much larger than the first above-described vessel (and exhibits relatively small movement behaviour due to its larger size).

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• Chemical & Material Sciences (AREA)
• Engineering & Computer Science (AREA)
• Combustion & Propulsion (AREA)
• Mechanical Engineering (AREA)
• Ocean & Marine Engineering (AREA)
• Ship Loading And Unloading (AREA)
• Laying Of Electric Cables Or Lines Outside (AREA)

Applications Claiming Priority (2)

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• 2011
  • 2011-02-11 NL NL2006183A patent/NL2006183C2/nl not_active IP Right Cessation
• 2012
  • 2012-02-09 WO PCT/NL2012/050071 patent/WO2012108769A1/fr active Application Filing
  • 2012-02-09 EP EP12705493.0A patent/EP2673188A1/fr not_active Withdrawn

Non-Patent Citations (1)

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