NL2028920B1

NL2028920B1 - Recirculating cylindrical rollers assembly for supporting an object on a rail, e.g. in a pile holding system

Info

Publication number: NL2028920B1
Application number: NL2028920A
Authority: NL
Inventors: Romeijn Eric
Original assignee: Itrec Bv
Priority date: 2021-08-04
Filing date: 2021-08-04
Publication date: 2023-02-17
Also published as: CN116615590A

Abstract

An assembly for supporting an object on a rail comprises a load bearing housing and an endless chain of steel cylindrical rollers arranged for recirculating along a closed path. The assembly comprises an elastically compressible resilient insert which is sandwiched between a steel central body and a steel raceway member above a work portion of the path, so that the central body is resiliently supported on an operative set of the cylindrical rollers via the insert and the steel raceway member.

Description

P35021NLOO

RECIRCULATING CYLINDRICAL ROLLERS ASSEMBLY FOR SUPPORTING AN OBJECT

ON A RAIL, E.G. IN A PILE HOLDING SYSTEM

The present invention pertains to an assembly for supporting an object on a rail, e.g. a pile holder that is configured for holding a pile, e.g. a monopile forming a foundation for supporting an offshore wind turbine, to be driven into the seabed.

For example, WO2019125172 discloses an X-Y motion supported pile holder having rails extending in the X-direction and rails extending in the Y-direction. The pile holder is supported on these rails by wheels. As the load on the wheels is very large, these wheels are commonly designed with a large diameter in view of stress distribution and friction.

In the case of a pile holder, the load supported on the rails increases in particular because there is a trend towards larger piles to be held by the pile holder as there is a trend towards larger offshore wind turbines. Hence, it is expected that in the near future piles need to be installed that are longer than 100 metres, possibly 120 metres or more. The weight of such piles may be more than 1000mt, possibly 1300mt or even more.

The present invention aims to provide an improved assembly for supporting an object on a rail, e.g. in view of ever increasing requirements, e.g. in the field of pile holding for installation of a foundation pile for an offshore wind turbine.

The invention provides an assembly according to claim 1.

When the inventive assembly is used in conjunction with the X-Y motion support of a pile holder, as in preferred embodiments of the invention, an advantage is that the effective height of the X-Y motion support for the pile holder can be reduced as no longer use is made of large diameter wheels for this purpose. This improves stability of the support of the load on the vessel and of the vessel including the load, e.g. so that control of the positioning thereof becomes easier. Furthermore, the rails are no longer subject to unfavourable localized mechanical loading at the relatively small interface between a wheels and the rail. This may allow to reduce the requirements on the mechanical properties of the rails. Also, compared to the known arrangement of large diameter wheels, the inventive assembly may provide a smooth movement of the load along the rails. For example, stick-slip effects may be reduced to the benefit of control of accurate dynamic positioning of the pile holder, which becomes increasingly more challenging as the weight to be handled (e.g. of the pile) is larger.

The rail may be mounted or mountable to a surface, e.g. on top thereof, e.g. on a vessel, e.g. to a deck thereof, whilst the object is able to move along the rail. The rail may be mounted to the surface via another such rail, as is for example the case in an embodiment of a construction according to the invention which will be discussed later. The rail may alternatively be mounted or mountable to extend sideways, or be suspended to support the object from above. The term ‘on’ is to be interpreted to include such configurations.

The assembly comprises a load bearing housing for carrying the object on the assembly, e.g. for mounting the object to the assembly. By carrying the object, and engaging with the rail, the assembly supports the object on the rail. In embodiments, the assembly is suitable for supporting the object on multiple rails, for example two parallel rails.

The assembly comprises an endless chain of steel cylindrical rollers, which are arranged for recirculating along a closed path defined by the assembly. For example, between 20 and 25 cylindrical rollers are arranged in the endless chain. The chain is formed by a row of the steel cylindrical rollers, the rotation axes thereof being parallel to each other, as is known in the art.

For example, the cylindrical rollers may be physically interconnected, or push each other forward via intermediate elements between adjacent rollers.

The closed path runs around a steel raceway member and a steel central body. Thus the steel raceway member and the steel central body form an inner circumference of the closed path. The path includes a work portion and a return portion. The work portion is defined by a load bearing surface of the raceway member of the assembly, in which work portion an operative set of the cylindrical rollers engages the rail. Thereby, the work portion supports the load of the object on the rail. The load bearing surface is generally smooth, and the raceway member having this surface is non-resilient, as it is made of steel. The cylindrical rollers also being made of steel, makes that friction between the cylindrical rollers and the load bearing surface is minimized. In the return portion, defined by a return surface of the steel central body, a remaining set of the cylindrical rollers is free from the rail. Thus, no cylindrical rollers of the remaining set engage the rail, and thus support the object on the rail. This may be achieved by having the return surface run, at a front and rear side of the load bearing surface, directly upwards from the load bearing surface. In an example the return portion has a section which is parallel to the work portion.

In operation, that is, when the object and the assembly moves in a longitudinal direction of the rail, the operative set of the cylindrical rollers moves along the work portion of the closed path in the opposite direction of this movement direction. In doing so, the cylindrical rollers roll over the rail and over the load bearing surface. In the return portion of the closed path, the cylindrical rollers move from the side of the work portion where the cylindrical rollers exit the work portion, along the return portion to the side of the work portion where the cylindrical rollers enter the work portion. In doing so, the cylindrical rollers roll over the return surface.

A practical shape of the closed path has a work portion that runs longitudinally along a plurality of cylindrical rollers, for example 6 - 10 cylindrical rollers, and runs along a top surface of the rail when the assembly engages with the rail, and has a straight part of the return portion, e.g. of equal length, that is above and parallel to the work portion. The straight part of the return portion and the work portion may be interconnected by semi-circular front and back portions of the closed path. Or, for example, the closed path is in the shape of a rounded rectangle with the long sides being formed by the work portion and the straight part of the return portion.

The engagement of the rails by the assembly may be only from above, however it is preferred that the assembly limits also the movement of the assembly with respect to the rail in the lateral direction of the rail. In an embodiment, the cylindrical rollers may be slightly concave.

The lateral movement relative to the rail may for example also be limited by providing one or more elements, e.g. rollers or wheels with a vertical rotation axis, which engage the rail laterally. These may be mounted to or integral with the assembly.

The cylindrical rollers may have a hardened surface to further reduce friction at the interfaces thereof with the rail and the load bearing surface.

According to the invention, the assembly comprises an elastically compressible resilient insert between the steel central body and the steel raceway. The central body is resiliently supported via the insert on the operative set of the cylindrical rollers.

The insert may, for example, be an elastically compressible resilient plate, on top of which the load bearing body is attached.

The central body is, preferably, attached to the resilient insert directly on top thereof.

In an embodiment, the central body has a recess which corresponds to the dimensions of the combination of the resilient insert and the raceway member, so that the resilient insert is flush with a bottom surface of the central body.

In an embodiment, the elastically compressible resilient insert is made of a composite material, e.g. that is adapted for use in bearings, such as a fibre-reinforced plastic material.

For example, a thermoset composite bearing material incorporating technical fabrics impregnated with thermosetting resins and optionally further additives. For example, containing one or more of polyester fibers, aramid fibers, polyester resin, epoxy resin, PTFE, molybdenum disulfide, graphite, calcium carbonate. A particularly suitable material for the insert is presently known under the registered trade mark Orkot®.

The elastically compressible resilient insert provides for a forgiving support of the central body, and thereby, of the object supported by the assembly, on the operative set of the cylindrical rollers. By the resilient support of the object on the operative set of the cylindrical rollers, the load of the object exerted on the central body is distributed over the cylindrical rollers, to the benefit of a favourable mechanical loading of the cylindrical rollers and the rail.

By the insert, the insert thus absorbs local discontinuities in the load profile along the work portion, e.g. edge loading, misalignment, including discontinuities at the interface of the cylindrical rollers and the rail and/or of the cylindrical rollers and the raceway surface, such as dents, bumps, or small slants in these surfaces.

The raceway member forms the load bearing surface and guides the operative set of the cylindrical rollers between the load bearing surface and a surface of the rail. The raceway member is disposed between the resilient insert and the operative set of the cylindrical rollers, and defines, at the side of the operative set of the cylindrical rollers, the work portion of the path. Via the raceway member, e.g. raceway plate, the central body is thus supported on the operative set of rollers. The load bearing surface engages the cylindrical rollers, and guides them as these move along the work portion of the path.

The resilient insert engages the raceway member, e.g. is attached thereto at their interface, e.g. directly on top thereof. To be able to benefit from the effects of the insert, the movement of the raceway member relative to the central body is preferably not limited, e.g. by directly fixedly interconnecting the raceway member to the central body.

Preferably, the resilient insert is embodied as a plate. Preferably, the raceway member is embodied as a plate. Most preferably, the resilient insert and raceway member are both plates, preferably of equal width and length, and preferably stacked on top of each other so that their sides axially coincide. Preferably, the resilient insert, alike the raceway member, longitudinally covers only the work portion.

The central body, preferably, engages, or is preferably attached to, the resilient insert directly on top thereof.

In an embodiment, the central body has a recess e.g. which corresponds to the dimensions of the attached resilient insert and raceway member, with the resilient insert and raceway member being disposed in the recess so that these are axially enclosed thereby. Preferably, this is done so that the load bearing surface of the raceway member is flush with the return surface of the central body, and the central body and the inner circumference of the closed path as formed by the load bearing and return surface runs fluently and continuously.

Alike the load bearing surface, the return surface of the central body is smooth, and the central body is non-resilient as it is made of steel, so that any friction between the cylindrical rollers rolling over the return surface is reduced to a minimum.

In an embodiment, the raceway member and the resilient insert are both in the form of a plate, and the raceway member has a smaller thickness than, e.g. corresponding to around 55 - 65% of, a thickness of the raceway member.

In an embodiment, the assembly further comprises a second endless chain of recirculating cylindrical rollers, arranged for recirculating along a second closed path of which a work portion and a return portion are defined by respectively a second flat load bearing surface of a second steel raceway member of the assembly and a second return surface of the central body. The two closed paths of the assembly are laterally juxtaposed and parallel to one another, so that the cylindrical rollers, in operation, move in the same direction. In the work portion, an operative set of the cylindrical rollers of the second endless chain engages the rail, and in the return portion a returning portion of these cylindrical rollers is free from the rail.

In this embodiment, the central body thus has two return surfaces defining the respective return portions, and is resiliently supported on the cylindrical rollers of both endless chains via respective raceway members and respective resilient inserts, or alternatively one integral resilient insert for distributing the load over the two operative portions as well. Having one central body for the two endless chains, may provide advantages in terms of robustness, compactness and ease of manufacturing. In an alternative embodiment, instead of an integral

-B- central body for both endless chains, a separate second central body may be provided for the second endless chain, having the return surface thereof.

In an embodiment, the assembly is provided, at least around the work portion of the recirculating cylindrical rollers, with one or more seals. These seals may extend between bottom surfaces of the assembly which enclose the work portion, and the upper surface of the rail. For example the seals extend between bottom surfaces of walls of the assembly, e.g. longitudinal wall parts and end walls which together enclose the work portion, which will be discussed later, and the upper surface of the rail. The seals define, e.g. together with the walls and wall parts, between the load bearing surface and the upper surface of the rail a grease chamber for the operative set of the recirculating cylindrical rollers. For example, the seals are in a cross-section thereof substantially V-shaped. The grease inside the grease chamber may further reduce the amount of friction between at least the load bearing surface and the cylindrical rollers, for example also between the return surface and the cylindrical rollers. The seals defining the grease chamber, are provided for keeping the grease inside the grease chamber and/or for preventing grease and/or dirt to enter the grease chamber from outside the grease chamber. Therefore these seals, preferably, abut the upper surface of the rail as tightly as possible, e.g. even during motion of the assembly along the rail, so that as less as possible of the grease escapes from the grease chamber or enters it between the rail and the seal. Preferably, this abutment is such as to not significantly increase the friction between the assembly and the rail upon movement thereover. For example, an inner seal is provided for keeping the grease inside the grease chamber, and an outer seal is provided for preventing grease and/or dirt to enter the grease chamber.

In an embodiment, the housing is provided at a front and/or rear side, facing a longitudinal direction of the rail, and at a longitudinal distance from the work portion, with respectively a front and/or rear scraper engaging the upper surface of the rail for cleaning the rail, for example from any grease that has escaped from the grease chamber, when provided.

In an embodiment, the housing comprises a front and rear vertical end wall which extend laterally respectively at the front and rear side of the assembly, and a front and rear guide wall which are attached to respectively the front and rear end wall and define respectively a front and rear section of the return portion of the closed path opposite the return surface.

Preferably the attachment is via one or more elongate mounting elements, for example one or more bolts, screws or similar, which extend perpendicularly through the end walls and longitudinally stick into the guide walls. The seals may be provided to extend along these end walls, e.g. be attached thereto underneath the end walls.

In an embodiment wherein the assembly comprises two endless chains of cylindrical rollers, and thus two closed paths, as described before, the housing may comprise a second front guide wall and a second rear guide wall, which are attached to respectively the front and rear end wall and define respectively a front and rear section of the return portion of the second closed path opposite the second return surface. The fact that the guide walls associated with each of the endless chains are at either longitudinal side of the assembly attached to the same end wall, may advantageously improve the stability of the assembly and the distribution of the load forces over the assembly so as to favour the mechanical stress profile in the material of the housing.

In an embodiment having a front and/or rear scraper, the housing of the assembly further comprises a front and/or rear frame which protrude respectively from the front and/or rear end wall in a frontward and/or rearward direction, wherein the front and/or rear scraper is mounted underneath the respective frame at a longitudinal end thereof.

The central body may in embodiments be attached to the housing. The central body may in other embodiments be integral with the housing. The treads for guiding the head ends of the roller axes and/or the longitudinal wall parts may be integral with the central body. Integrating the parts may provide advantages in terms of robustness and ease of manufacturing.

In an embodiment the cylindrical rollers of the endless chain(s) each rotate around a respective roller axis of which head ends run aver respective treads formed by vertical protrusions from the central body. These treads extend longitudinally along the closed path at respective lateral sides of the closed path.

In an embodiment the assembly further comprises left upper and lower and right upper and lower longitudinal wall parts. These longitudinal wall parts form upper and lower vertical protrusions from the central body at the left and right ends thereof, and extend longitudinally over at a least length of the closed path. Preferably, the left upper and lower are interconnected, and the right upper and lower longitudinal wall parts are interconnected, via one or more elongate mounting elements, e.g. one or more bolts, screws or similar, which vertically extend inside the respective upper and lower longitudinal wall parts and through the respective lateral end of the central body. Preferably, multiple elongate mounting elements are distributed longitudinally along the wall parts. This configuration with elongate mounting elements may benefit the distribution of the mechanical load over the wall parts and the central body, transferring the load through the mounting elements. Furthermore, the configuration provides stability and robustness to the assembly.

In an embodiment wherein there are two endless chains, and thus two closed paths, the assembly may further comprise intermediate upper and lower longitudinal wall parts, which form upper and lower vertical protrusions from the central body in between the two closed paths, and which extend longitudinally over at least a length of the closed path. Alike the left and right longitudinal wall parts, also the intermediate upper and lower longitudinal wall parts are preferably interconnected via one or more elongate mounting elements, e.g. one or more bolts, screws or similar, which vertically extend inside the respective upper and lower longitudinal wall parts and through a central part of the central body. Preferably, multiple elongate mounting elements are distributed longitudinally along the wall part.

In an embodiment wherein the end walls are present, the longitudinal wall parts are preferably connected to the end walls via one or more elongate mounting elements which extend perpendicularly through the end walls and longitudinally stick into the longitudinal wall parts.

In an embodiment, at a front and rear side of the load bearing surface, the return surface runs upwardly directly from the load bearing surface. This is to achieve that only the operative cylindrical rollers inside the work portion of the path are in contact with the rail, and thus support the load on the rail. Thus, the cylindrical rollers in the return portion do not support the load on the rail. Preferably a frontmost and/or rearmost section of the raceway member additionally slants slightly upwards towards the return surface, so as to achieve a smooth unloading of the roller that is exiting the work portion.

The invention furthermore provides the use, onboard a vessel, of an assembly comprising an endless chain of linear recirculating cylindrical rollers, for example the assembly as described herein, for supporting an object on a rail that is mounted to the vessel, e.g. to a deck thereof, whilst moving the object along the rail in an X-Y plane of the vessel. As discussed, the use of the assembly may advantageously obviate the use of wheels and therefore reduce or eliminate the mentioned disadvantages associated with such wheels, as one or more assemblies may be used instead of wheels. The assembly as described is particularly suited for the use, because the load of the object is distributed evenly over the rollers, which may be crucial in view of the generally immense weight of the objects to be handled in offshore applications - for example, foundations or wind turbines, or parts thereof.

The invention furthermore provides a system of one or more rails adapted to be mounted to a vessel, e.g. to a deck thereof, and one or more assemblies for supporting an object on the one or more rails whilst the object moves along the one or more rails. The one or more assemblies are preferably embodied as described herein before. For example, the system comprises two or more rails in parallel, which are each engaged by one or more respective assemblies. Thus, the load of the object may be distributed over the assemblies.

Each assembly is configured to engage with one of the rails and comprises a central body for engaging and carrying the object on the assembly, e.g. for mounting the object to the assembly.

Each assembly comprises an endless chain of cylindrical rollers, which are arranged for recirculating along a closed path defined by the assembly. The path includes a work portion and a return portion. The work portion is defined by a load bearing surface of the assembly, in which work portion an operative set of the cylindrical rollers engages the rail. In the return portion, a returning portion of the cylindrical rollers is free from the rail.

Preferably each assembly comprises a resilient insert via which the central body is resiliently supported on the raceway member and thus on the operative set of the cylindrical rollers, as described herein before.

The invention furthermore provides a construction for supporting an object on a vessel, which comprises two systems as described, namely a first and a second system. Of the first system, the one or more rails are one or more first rails which extend in a first direction, and the one or more assemblies are one or more first assemblies. Of the second system, the one or more rails are one or more second rails which extend in a second direction at an angle with the first direction, and the one or more assemblies are one or more second assemblies. The construction is configured to support the object on the one or more first rails via the one or more first assemblies and the one or more first rails are supported on the one or more second rails via the one or more second assemblies, so that the object is movable along the rails in both the first and the second direction. Thus, the object can be moved in both the first and the second direction, so that combined movements in the X-Y plane are possible.

In an embodiment, the first rails are directly mounted on the one or more second assemblies in order to be supported on the one or more second rails.

In another embodiment, the construction further comprises a positioning frame, via which the one or more first rails are mounted on the one or more second assemblies, so that the first system, and thereby the object, is moveable over the one or more second rails by moving the positioning frame over the one or more second rails.

Preferably, the first direction is perpendicular to the second direction, so that the directions follow, and can advantageously be controlled as in, a conventional coordinate system. For example, the construction can be such that when placed on a vessel, the first direction corresponds to the X-direction of the vessel, i.e. the longitudinal axis of the vessel, and the second direction corresponds to the Y-direction of the vessel. In an embodiment, the first and second rails are both straight, e.g. extending perpendicularly to one another. In another embodiment, one or more of the first and/or of the second rails are curved, for example forming a circle segment, for example for enabling rotation of an object supported thereon.

The invention furthermore provides a combination of an object and a system according to any one or more of claims 18-20, or a construction according to claim 21, wherein the object is a tool for handling an offshore structure, e.g. an elongate offshore structure, e.g. the tool being a pile holding tool for handling a pile, e.g. a pile adapted to support an offshore wind turbine, wherein the combination further comprises one or more actuators for moving the tool over the one or more rails, and thus relative to the vessel, when mounted to the vessel.

In an embodiment, the tool is resiliently mounted on the one or more assemblies. Thereby, the load of the tool can advantageously be distributed evenly over the assemblies.

In an embodiment, the combination is configured for holding a pile at a vessel, e.g. a pile adapted to support an offshore wind turbine, e.g. for holding the pile during installation of the pile at an offshore location next to the vessel. Therein, the object to be supported on the one or more rails by the assemblies is a pile holding tool. A pile holding tool is known in the art to comprise a support structure and a pile holder, mounted to the support structure. The pile holder comprises a ring, and is configured to hold a pile in at least a vertical orientation with that ring. The ring comprises multiple pile engaging devices distributed about the circumference of the ring, each pile engaging device being adapted to engage an exterior of a pile extending through the ring, e.g. each pile engaging device comprising one or more pile guiding rollers.

In the combination, the support structure of the pile holding tool is mounted on the one or more assemblies.

In an embodiment, the combination is a combination of a tool for handling an offshore structure, for example the pile holding tool as described, and the construction as described.

Therein, the construction further comprises a positioning frame, via which the one or more first rails are mounted on the one or more second assemblies, so that the first system, and thereby the object, is moveable over the one or more second rails by moving the positioning frame over the one or more second rails. For moving the tool in the second direction, the actuators engage the positioning frame so as to move the positioning frame, and therewith, the first system and the tool over the one or more second rails. For moving the tool in the first direction, the actuators engage the tool, so as to move the tool over the one or more first rails.

In an embodiment, the combination is configured to, when the combination is mounted to the vessel, maintain a predetermined X-Y location of the pile holder independent of the motion of the vessel, the vessel being in floating condition, by the actuators moving the pile holder over the one or more first rails and the one or more second rails, and thus relative to the vessel.

Means for maintaining a predetermined X-Y location are known in the art for vessel-mounted pile holding tools.

In an embodiment the combination comprises an active motion compensating actuation system for moving the support structure over the rails, and thus relative to the vessel, the active motion compensating actuation system comprising the one or more actuators. The actuators comprise a first actuator, e.g. a cam track mountable to the deck of the vessel and a drive mounted on the positioning frame engaging the cam track, for moving the positioning frame over the one or more first rails, and a second actuator, e.g. a cam track mounted on the support structure and a drive mounted on the positioning frame engaging the cam track, to move the support structure over the one or more second rails. The actuation system comprises an active wave-induced motion compensation mode in which the actuation system is operated to maintain a predetermined X-Y location of the pile holding tool independent of the motion of the vessel.

In an embodiment, the ring of the pile holder comprises a ring base and one or more movable jaws, e.g. two semi-circular jaws, each jaw being movable between a closed position, wherein the ring forms a closed annulus, and an opened position. Such a pile holder is known, e.g. from WO2019125172.

The assemblies according to the invention, in particular the use thereof in a system or construction according to the invention, is furthermore envisaged for application with a lifting tool, e.g. a lifting beam, which is to be suspended from a lifting device, e.g. a crane, e.g. from one or more hoisting cables thereof. The lifting tool, configured to engage a load to couple with the load, can therein be connected to the assemblies, while the rail is connected to the lifting device, e.g. the hoisting cables thereof, e.g. indirectly connected. Moving the load over the rail via the assemblies, e.g. by means of an actuator, moves the load relative to the lifting device, so as to enable a change in the position and/or orientation of the load relative to the lifting device.

The assemblies according to the invention, in particular the use thereof in a system or construction according to the invention, is furthermore envisaged for application in a lift- removal of an offshore platform, e.g. a topsides structure supported by a steel jacket with multiple legs, by means of a decommissioning vessel for that purpose - e.g. the pioneering spirit. The lift-removal operation involves giant beams to be slid in their longitudinal direction along deck connected first rails, for moving outer ends of the beams (further) outboard the vessel, towards pre-installed bearing brackets that are mounted on the upper sections of the steel jackets legs. Horse shoes mounted to the outer ends of the beams are connected to the bearing brackets, after which the upper sections are lifted from the rest of the jacket - and thereby, the topsides structure is lifted therefrom. The vessel, and therewith the topside structure, is subsequently moved away from the jacket. The giant beams may furthermore be movable along second rails in a transverse direction as well. The assemblies according to the invention may be used between the beams and the first rails, and between the first and second rails.

The assemblies according to the invention are furthermore envisaged to be used in a particular construction according to the invention, between one or more first and second rails extending in respective directions, e.g. perpendicular directions. In this construction, other than in the earlier described construction, the first and second assemblies are both provided at a crossing of the first and second rails, in stacked unit. A lower portion of such unit is configured to engage one of the second, lower rails, by means of one or more of the second assemblies provided in the lower portion. An upper portion of the unit is configured to engage one of the first, upper rails, by means of one or more of the first assemblies provided in the upper portion. Inherently, the work portions of the first assemblies are directed to the first rails in order to engage these, and those of the second assemblies directed to second rails in order to engage these. In an embodiment, the portions of the stacked may be pivotable relative to one another, e.g. about a vertical swivel axis, in order to facilitate sliding over rails that have a varying orientation relative to one another along the track. In an embodiment, the first and second rails are both straight, e.g. extending perpendicularly to one another. In another embodiment, one or more of the first and/or of the second rails are curved, for example forming a circle segment, for example for enabling rotation of an object supported thereon.

The invention furthermore provides a vessel, e.g. a vessel for handling an offshore structure, e.g. a pile, at an offshore location, e.g. for installing the structure at the offshore location. The vessel may be a floating vessel, or e.g. a jack-up vessel. In an embodiment the vessel is provided with one or more systems according to the invention, wherein the one or more rails are mounted to the vessel, e.g. are a deck-mounted rails. In an embodiment the vessel is provided with one or more constructions according to the invention, wherein the one or more second rails are mounted to the vessel, e.g. are deck-mounted rails, and wherein preferably the first direction is an X-direction of the vessel and the second direction is a Y-direction of the vessel. In an embodiment the vessel is provided with one or more combinations according to the invention, wherein the one or more rails, i.e. the one or more first rails, when present, are mounted to the vessel, e.g. are deck-mounted rails, and wherein when present, preferably the one or more first rails extend in the X-direction of the vessel and the one or more second rails in the Y-direction of the vessel.

In an embodiment, the vessel is provided with a combination of a pile holding tool and the system or construction according to the invention, and the pile holding tool is moveable along the one or more rails between a stowed position in which the a ring of the pile holder extends, seen in the X-Y plane of the vessel, within the contour of the vessel, and an operational position, in which the ring of the pile holder extends, seen in the X-Y plane of the vessel, outboard the vessel. The stowed position enables a more compact and stable vessel when the pile holding tool is not being used, and enables to access the parts of the tool from the deck, e.g. for maintenance.

The invention furthermore provides a method for handling an object on a floating vessel, wherein use is made of a vessel according to the invention.

The invention furthermore provides a method for handling an object on a floating vessel, comprising: - supporting an object on one or more rails mounted to offshore vessel, via one or more assemblies comprising an endless chain of linear recirculating cylindrical rollers, and - moving the object along the one or more rails, and therewith, relative to the vessel, which moving involves for one or more of the assemblies, recirculating the endless chain of linear recirculating cylindrical rollers along a closed path defined by each assembly, an operative set of the cylindrical rollers engaging the rails and moving in a direction opposite to the movement of the object. Therein, the assemblies may each be according to the invention.

The methods according to the invention advantageously provide an alternative to the use of wheels, so that they may obviate the use thereof, and therewith, reduce or eliminate the advantages associated therewith.

In an embodiment, the one or more rails comprise one or more first rails which extend in a first direction, and one or more second rails which extend in a second direction at an angle with the first direction, and the one or more assemblies comprise one or more first assemblies, and one or more second assemblies. The object is supported on, and moves over, the one or more first rails via the one or more first assemblies, and the one or more first rails are supported on, and move over, the one or more second rails via the one or more second assemblies, so that the object is movable along the rails in both the first and the second direction. Preferably, the second direction is perpendicular to the first direction. The moving along the one or more second rails of the object, the one or more first rails and assemblies, and thereby the object, is done by moving a positioning frame, via which the one or more first rails are mounted on the one or more second assemblies, along the one or more second rails.

In an embodiment, the movement of the object is actuated such as to compensate for motions of the vessel in the X-Y plane of the vessel.

In an embodiment, the object is a pile holding tool, and the supporting of the object comprises supporting on the one or more rails, i.e. on the first rails, when present, a support structure of the pile holding tool. The support structure is mounted on the one or more assemblies, i.e. on the one or more first assemblies, when present, and supports a pile holder of which a ring extends outboard of the vessel. Therein the method further comprises: - holding a pile, e.g. a pile adapted to support a wind turbine, such that it extends in a vertical orientation through the ring of the pile holder of the pile holding tool, wherein pile engaging devices distributed about the circumference of the ring engage the exterior of the pile, and - lowering the pile into a body of water on which the vessel is floating while being held and guided by the pile engaging devices, wherein the motion compensation is executed at least during the lowering of the pile.

In an embodiment, the movement of the pile holding tool is furthermore actuated such as to include, prior to at least the lowering of the pile, moving the pile holder from a stowed position, in which the a ring of the pile holder extends, seen in the X-Y plane of the vessel, within the contour of the vessel, to an operational position, in which the ring of the pile holder extends, seen in the X-Y plane of the vessel, outboard the vessel. In an embodiment, the movement of the pile holding tool is furthermore actuated such as to include, after at least the lowering of the pile and releasing the pile from the pile holder, including disengaging the pile engaging devices from the pile, moving the pile holder from the operational position to the stowed position.

In an embodiment, the moving of the tool over the one or more rails may be actuated to include correcting, e.g. damping, of any displacement of the tool due to accidental bumping of the pile against the ring when the pile is being inserted into the ring prior to the lowering of the pile. Therein, the cylindrical rollers may or may not roll over the rails, for example the rotation thereof is locked so that these slide over the rails. Furthermore, while the pile is being held by the pile holder, e.g. while the pile is being lowered, the moving may be actuated to correct an undue tilting or an undue displacement of the monopile, e.g. as a consequence of sea motions or the influence of wind. For example, a toppling forward of the pile may be corrected by moving the pile holder forwards.

The invention is hereinafter described with reference to the appended drawings. In the drawings, figures 1a,b illustrate, in a side view, a combination according to the invention, respectively in a stowed position and an operational position, figure 1c illustrates, in a top view with a detail, the same combination, figures 2a,b illustrate, in a top and side view, a combination according to the invention, respectively in a stowed position and an operational position, figures 3a,b illustrate, in a side view, a longitudinal cross-section through an assembly according to the invention, figure 4 illustrates in the view of figure 3a, the same assembly in operation on a rail, figure 5 illustrates in a top view, the same assembly, figure 6 illustrates in a side-cross-sectional view, two of the assemblies according to the invention in series being used in a combination according to the invention, figure? illustrates, in a front view, a lateral cross-section of the assembly, figure 8 illustrates, in a front view, a lateral cross-section of a system according to the invention, figure 9 illustrates, in a side view, a longitudinal cross-section through a system according to the invention, figure 10 illustrates a bottom view of the same system, figure 11 illustrates a vessel according to the invention and a method according to the invention, and figure 12a-b schematically illustrate exemplary constructions according to the invention.

It is noted, that the figures are schematical representations of the invention, and may e.g. not all be true to nature or scale.

Figures 1a, 1b and 1c show an illustrative combination 1 according to the invention, namely a combination of an pile holding tool 2,3 and a construction 4,31,32,41,42 according to the invention. The tool is suitable for handling a pile 6, in particular a pile adapted to support an offshore wind turbine. The combination 1 is to be mounted on a vessel 5, as is shown in figure 7 for a jack-up vessel 5 which is suitable for handling and installing the pile at an offshore location next to the vessel. The combination 1 may however also be mounted on a floating vessel (not shown), e.g. suitable for such handling and installation of offshore structures.

The construction comprises a first and second system according to the invention. The first system comprises two parallel first rails 31 which extend in a first direction X, and multiple assemblies 32 according to the invention which each engage one of the rails 31. The second system comprises two parallel second rails 41 which extend in a second direction Y, which is perpendicular to the first direction, and multiple assemblies 42 which each engage one of the second rails 41.

The construction is configured to support the pile holding tool 2,3 on the one or more first rails 31 via the one or more first assemblies 32, and the one or more first rails 31 are supported on the one or more second rails 41 via the one or more second assemblies 42, onto which the first rails 31 are both mounted via a positioning frame 4. Thereby, the tool 2,3 is movable along the rails 31,41 of the construction in both the first and the second direction X,Y. The combination further comprises one or more actuators 43 for moving the tool 2,3 over the one or more rails 31,41. When mounted to the vessel 5 as in figure 7, the rails 31,41 may in particular extend in the X,Y direction of the vessel 5 as shown, respectively. Therein, moving the tool over the rails 31,41, moves the tool 2,3 relative to the vessel 5 in these directions.

The pile holding tool 2,3 supported on the construction comprises a support structure 3, which is mounted on the one or more assemblies 31,41, and a pile holder 2. The pile holder is mounted to the support structure 3, and comprises a ring 21. The pile holder 2 is configured to hold a pile 6 in at least a vertical orientation with that ring 21, as shown in figure 7. The ring 21 comprises multiple pile engaging devices 22 distributed about the circumference of the ring 21. Each pile engaging device 22 is adapted to engage an exterior of a pile 6 extending through the ring 21 and comprises one or more pile guiding rollers.

The combination 1 is configured to, when mounted to a vessel, maintain a predetermined X-Y location of the pile holder 2,3 independent of the motion of the vessel by the actuators moving the pile holder 2,3 over the one or more first rails 31 and the one or more second rails 41, and thus relative to the vessel. This is of particular use when the vessel is in floating condition and subject to motions of the sea, e.g. currents and waves, and wind. The combination may comprise an active motion compensating actuation system for moving the support structure 3 over the rails 31,41, and thus relative to the vessel.

As shown in figures 1a and 1b, the pile holding tool 2,3 is moveable along the one or more rails 31,41 between a stowed position (fig. 1a) and an operational position (fig. 1b). As may be envisaged from figure 7, when the combination 1 is mounted to a vessel 5 in the manner as shown, in the stowed position (fig.1a) the ring 21 of the pile holder 2 extends, seen in the X-Y plane of the vessel 5, within the contour of the vessel 5, and in the operational position (fig. 1b) the ring 21 extends, seen in the X-Y plane of the vessel 5, outboard the vessel 5. In the operation position, a pile 6 can be lowered through the ring 21 while being held by the pile engaging devices 22.

Figures 2a and 2b illustrate a combination 1 according to the invention wherein a similar pile holding tool 2,3 as shown in figs.1a-c is supported on first rails 31, which are straight, and enable the stowed and operational position alike in figs.1a-b. The second rail 41 is curved, forming a circle segment, for enabling rotation of the pile holding tool 2,3 supported thereon relative to the deck 51. A pile holder being supported on such straight rails, on top of curved rails, is known from the non-prepublished application NL2028124 by the applicant, along with the possibilities for movement of the pile holder along these rails.

Figures 3a and 3b show a single one of the assemblies 32,42 by means of which the pile holding tool 2,3 is supported on the rails 31,41. Both an assembly 32 onto which the support structure 3 of the tool 2,3 is mounted, and an assembly 42 onto which the positioning frame 4 is mounted, may be embodied as shown. Therefore, the indications in the figures refer both to an embodiment of an assembly 32 and of an assembly 42.

The assembly 32 or 42 comprises a load bearing housing 32H or 42H, with a top plate for carrying the tool 2,3 on the assembly 32 or 42.

The assembly 32,42 comprises an endless chain of steel cylindrical rollers 32R,42R, which are arranged for recirculating along a closed path 32P,42P around a steel raceway member 32G,42G and a steel central body 32B,42B of the assembly 32,42. The steel central body

32B, 42B is attached to the load bearing housing 32H, 42H via a number of elongate mounting elements, namely bolts 32M, 42M. The path 32P, 42P is indicated in figure 3a and figure 4. The path 32P,42P has a work portion 32Pw,42Pw defined by a flat load bearing surface 32L,42L of the steel raceway member 32G,42G of the assembly 32,42. The work portion 32Pw,42Pw is indicated in figure 4 by the dashed rectangle. In this work portion 32Pw,42Pw, an operative set of the cylindrical rollers 32R,42R engages the rail 31,41. The path 32P,42P also has a return portion 32Pr,42Pr which is defined by a return surface 32T, 42T of the steel central body 32B, 42B of the assembly. In the return portion a remaining set of the cylindrical rollers 32R,42R is free from the rail 31,41. The return portion 32Pr,42Pr has a section which is parallel to the work portion 32Pw,42Pw. The work portion 32Pw,42Pw and the parallel section of the return portion 32Pr,42Pr are connected at the front and rear side of the assembly 32,42 by a respective front and rear semi-circular section to form the complete closed path 32P,42P.

The return surface 32T,42T, see figure 3b, defines the return portion 32Pr,42Pr of the closed path 32P,42P. The return surface is formed by the steel out of which the central body 32B,42B is made. The load bearing surface 32L,42L and the return surface 32T,42T define, at the side of the cylindrical rollers 32R,42R, respectively the work portion 32Pw,42Pw and the return portion 32Pr,42Pr of the path 32P,42P. The semi-circular sections connecting the parallel sections of the path 32P,42P are at the opposite side of the path defined by the front and back guide walls 32Wg,42Wg, see figure 3a, figure 5 and figure 9.

The assembly 32,42 comprises a resilient insert 321,42] in the form of a resilient plastic plate, e.g. made of a fibre reinforced plastic material, e.g. adapted for use in bearings. The central body 32B,42B via this resilient insert 321,421 and the raceway member 32G,42G resiliently supported on the operative set of the cylindrical rollers 32R, 42R, see figures 3a,3b and 4.

Thereto the resilient plate 321, 421 is sandwiched between the central body 32B, 42B and the raceway member 32G, 42G above the work portion 32Pw, 42Pw of the path 32P,42P.

The raceway member 32G,42G is in the form of a raceway plate 32G,42G, and is alike the central body 32B,42B also made of steel. It guides the operative set of the cylindrical rollers 32R,32R between the load bearing surface 32L, 42L of the raceway plate 32G,42G and an upper surface 31S,41S of the rail 31,41. The raceway plate 32G,42G is disposed between the resilient insert 321,42] and the operative set of the cylindrical rollers 32R,42R, and defines, at the side of the operative set of the cylindrical rollers 32R,42R, the work portion 32Pw,42Pw of the path 32P,42P. In the shown embodiment, The raceway plate 32G,42G and the resilient insert 321,42] have the same dimensions in the axial plane and are stacked on top of each other such that their longitudinal and lateral edges axially coincide. The thickness of the raceway member 32G,42G is smaller than the thickness of the raceway member 32G,42G: it corresponds to around 60% of the thickness of the raceway member 32G,42G. The central body 32B,42B comprises a recess inside which the resilient insert 321,421 and the raceway plate 32G,42G are contained and axially enclosed. The raceway plate 32G,42G is flush with the longitudinally adjacent return surface 32T,42T of the central body 32B,42B.

As illustrated in figures 5 and 7, an embodiment of an assembly 32,42 according to the invention may further comprise a second endless chain of linear recirculating cylindrical rollers 32R,42R, arranged for recirculating along a second closed path 32P,42P defined by the assembly 32,42. The two paths 32P,42P are laterally juxtaposed and parallel to one another. The second path 32P,42P, also includes a work portion 32Pw,42Pw in which an operative set of the cylindrical rollers 32R,42R engages the rail 31,41, and a return portion 32Pr, 42Pr in which a returning portion of the cylindrical rollers 32R,42R is free from the rail 31,41. The work portion 32Pw,42Pw of the second closed path 32P,42P is defined by a second load bearing surface of a second raceway member. The return portion of the second path 32P,42P is defined by a second return surface of the central body 32B, 42B. Thus the central body 32B,42B has in this embodiment two load bearing surfaces 32L,42L and two return surfaces 32T,42T defining the respective work portions 32Pw,42Pw and return portions 32Pr,42Pr, and is integral for association with both endless chains. The central body is here resiliently supported on the respective operative portions of the cylindrical rollers of both endless chains via the respective raceway members, a second resilient insert containing a plastic material being sandwiched between the central body (32B,42B) and the second raceway member.

The housing 32H,42H of the assembly 32,42 comprises a front and rear vertical end wall 32We,42We which extend laterally respectively at the front and rear side of the assembly, and a front and rear guide wall 32Wg,42\Wg which are attached to respectively the front and rear end wall 32We,42We. The front guide wall 32Wg,42Wg defines a front section of the return portion 32Pr,42Pr of the closed path 32P,42P opposite the return surface 32T,42T, and the rear guide wall 32Wg,42Wg defines a rear section of the return portion of the closed path 32P,42P. The attachment is via multiple bolts which extend perpendicularly through the end walls and longitudinally stick into the guide walls.

In the embodiment with two endless chains, see figures 5,7 and 8, the housing 32H,42H comprises a second front guide wall and a second rear guide wall, which are attached to respectively the front and rear end wall 32We,42We and define respectively a front and rear section of the return portion of the second closed path 32P,42P opposite the second return surface 32T,42T.

As shown best in figure 7 for the embodiment with two endless chains of cylindrical rollers 32R,42R, the cylindrical rollers 32R,42R of the assembly 32,42 each rotate around a respective roller axis 32A,42A of which head ends 32E,42E run over respective treads 32D,42D formed by vertical protrusions from the central body 32B,42B extending longitudinally along the closed path 32P,42P at respective lateral sides of the closed path 32P,42P.

Figure 7 also shows that the assembly 32,42 comprises left upper and lower and right upper and lower longitudinal wall parts 32W,42W which form upper and lower vertical protrusions from the central body 32B,42B at the left and right ends thereof, and which extend longitudinally over at a least a length of the closed path 32P,42P. The left upper and lower wall part 32W,42W are interconnected via multiple bolts 32M,42M, see also figure 5, and the right upper and lower longitudinal wall parts 32W1,42W are interconnected via multiple bolts as well. These bolts 32M,42M vertically extend inside the respective upper and lower longitudinal wall parts 32W,42W and run through the respective lateral end of the central body 32B,42B. Figure 5 shows that the bolts 32M,42M are distributed longitudinally along the wal parts 32WI,42WI.

As indicated in the assembly 32,42 of figures 9 and 10 in a side and bottom view, and visible in figure 4 as well, the housing 32H,42H of the assembly 32,42 may be provided, at least around the work portion of the recirculating cylindrical rollers 32R,42R, with seals 325,428 between the end walls 32We,42We and longitudinal wall parts 32Wl,42WI, and the upper surface 315,418 of the rail 31,41. The walls 32We,32Wl,42We, 42W and the seals 325,428 define between the load bearing surface 32L,42L and the upper surface of the rail 31,41 a grease chamber 32H,42H for the operative set of the recirculating cylindrical rollers 32R,42R.

The seals 315,328 may in a cross-section thereof be substantially V-shaped - see figure 4.

The assembly 32,42 with two endless chains further comprises intermediate upper and lower longitudinal wall parts 32Wi,42Wi, see figures 5 and 7, which form upper and lower vertical protrusions from the central body 32B,42B in between the two closed paths 32P,42P, and which extend longitudinally over at least a length of the closed path 32P,42P. The intermediate upper and lower longitudinal wall parts 32Wi,42Wi are interconnected via multiple bolts 32M,42M, which vertically extend inside the respective upper and lower longitudinal wall parts 32W,42WI and through a central part of the central body 32B,42B.

Figure 5 shows that these bolts 32M,42M are distributed longitudinally along the wall part 32Wi,42Wi.

The longitudinal wall parts 32W,32Wi,42W,42Wi are each connected to the end walls 32We,42We via bolts which extend perpendicularly through the end walls 32We,42We and longitudinally stick into the longitudinal wall parts 32V,32Wi,42\W,42Wi. This is visible in figure 5.

As may be verified in figures 3a and 3b, at a front and rear side of the load bearing surface 32L.42L, the return surface runs upwardly directly from the load bearing surface 32L,42L.

Furthermore a frontmost and/or rearmost section of the raceway member 32G,42G slants slightly upwards towards the return surface. Note that the upward slants are very subtle.

As shown in figure 9 (side view) and figure 10 (bottom view), the assembly 32,42 according to the invention may be provided at a front and rear side, facing a longitudinal direction of the rail 31,41, with a scraper 32C,42C engaging the upper surface 31S,41S of the rail 31,41 for cleaning the rail 31,41. The housing 32H,42H thereto further comprises a front and rear frame which protrude respectively from the front and rear end wall 32We,42We in a frontward and rearward direction. The front and rear scraper 32C,42C are mounted underneath the respective frame at a longitudinal end thereof.

Figures 4,6 and 8 illustrate a system according to the invention of a rail and an assembly according to the invention.

Figure 8 schematically illustrates, that in addition to the top surface 31S,41S of the rail, also a side surface of the rail, e.g. both side surfaces, may be engaged by a corresponding lateral guidance part of the assembly, for limiting lateral motion of the assembly, and therewith of the object 2,3, in lateral directions of the rail 31, 41. For example, as shown, a lateral guidance part comprises a sliding bearing and/or a roller arrangement, e.g. depending on load requirements.

Figure 6 shows the use of two assemblies 32,42 in series, engaging a rail 31,41 mounted on a vessel 5, for supporting an object 2,3. The object is moving over the rail 31,41 in the indicated direction Mz 3, and the operative part of the cylindrical rollers 32R,42R moves in the opposite direction Msgr 42r in the work portion 32Pw,42Pw of the closed path 32P,42P of the cylindrical rollers. The resilient insert 321,42! facilitates a resilient support of the object 2,3 on the cylindrical rollers 32R,42R, and thus on the rail 31,41 while the object 2,3 moves over the rail 31,41.

Figure 12a shows, schematically, an embodiment of a construction with a first rail 31 and a second rail 41, or parallel pairs of rails 31, 41 as illustrated in figure 12b. Herein the first rail(s) 31 are perpendicular to the second rail(s) 41. Also the first rail(s) 31 cross over the second rail(s) 31. A vertical spacing is present between each second rail 41 and first rail 31 at a crossing. For example, the second rail(s) 41 is stationary mounted to the hull of a vessel, e.g. to a deck of the vessel. For example, the first rail(s) 31 forms part of a tool of the vessel, e.g. a pile holder tool.

Other than in figures 1a-c and figure 2a-b, at the crossing of first and second rails 31, 41 first and second assemblies 32 and 42 are combined in a stacked unit 3242 that is provided in between the first and second rails 31,41.

The lower assembly 42 of the unit 3242 is configured to engage the second, lower rail 41.

The upper assembly 32 of the unit 3242 is configured to engage the first, upper rail 31.

Inherently, the work portion 32Pw of the first assembly 32 is directed towards the first rail 31, that is, upwards, and the work portion 42Pw of the second assembly 42 is directed to the second rail 41, that is, downwards, so that these work portions 32Pw and 42Pw engage, respectively, the bottom surface 31S of the first rail 31, and the top surface 41S of the second rail 41. Thus the work portion 32Pw and 42Pw form, respectively, a top portion and a bottom portion of the respective closed path 32P and 42P. This is shown in the schematic illustration of the unit 3242 below the construction, showing by dashed lines the closed paths 32P, 42P of the assemblies 32,42.

In the embodiment of figure 12a, the first and second rails 32,42 are both straight, extending perpendicularly to one another. When the second rail 41 is fixed to the deck 51, an object connected to the upper rail 31 may be moved in the direction of the first rail 31 since the first rail 31 is movable, and may be moved in the direction of the second rail 41 since the second rail 41 is movable - thus the unit 3242, and therewith rail 31 and the object, may be slid over the second rail 41.

In the schematic figure 12b, the same principle is applied to a construction of two parallel first rails 31 and two parallel second rails 42, wherein the same unit 3242 is provided between the rails at each crossing, so four times.

The figures, in particular figures 1a,1b, 6, and 11, illustrate a method for handling an object on a vessel, comprising supporting an object 2,3, namely a pile holding tool 2,3, on the first rails 31 of the construction shown in figures 1a,1b, and 1c, mounted to the vessel via the assemblies 32,42 of the combination. The support structure 3 of the pile holding tool 2,3 is mounted on the first assemblies 31, and support the pile holder 2, of which a ring 21 extends outboard of the vessel 5.

The method comprises moving the object 2,3, here the pile holding tool 2,3, along the one or more rails 31,41, and therewith, relative to the vessel. This moving involves for the assemblies 32,42, recirculating the endless chain of linear recirculating cylindrical rollers 32R,42R along the closed path 32P,42P defined by each assembly 32,42, the operative set of the cylindrical rollers 32R,42R engaging the rails and moving in a direction opposite to the movement of the pile holding tool 2,3.

The method further comprises: - holding a pile, here a pile 6 adapted to support a wind turbine, namely a monopile, such that it extends in a vertical orientation through the ring 21 of the pile holder 2 of the pile holding tool 2,3, wherein pile engaging devices 22 distributed about the circumference of the ring 21 engage the exterior of the pile, and - lowering the pile into a body of water on which the vessel 5 is floating while being held and guided by the pile engaging devices 22.

Although vessel 5 is a jack-up vessel in figure 11, the method is also envisaged to be executed on a floating vessel 5. In that case, the method preferably includes motion compensation to be executed at least during the lowering of the pile 6.

The movement of the pile holding tool 2,3 may furthermore be actuated such as to include: - prior to at least the lowering of the pile 6, moving the pile holder 2,3 from a stowed position, see fig.1a, in which the a ring 21 of the pile holder 2 extends, seen in the X-Y plane of the vessel, within the contour of the vessel, to an operational position, see fig.1b, in which the ring 21 of the pile holder extends, seen in the X-Y plane of the vessel, outboard the vessel, and/or - after at least the lowering of the pile and releasing the pile from the pile holder 2, including disengaging the pile engaging devices 22 from the pile, moving the pile holder 2,3 from the operational position fig. 1b to the stowed position fig. 1a.

Claims

CONCLUSIONS

1. Assembly (32,42) for supporting an object (2,3) on a rail (31,41) while the object (2,3) moves along the rail (31,41), the assembly (32 ,42) comprises a load-carrying housing (32H,42H) for supporting the object (2,3), the assembly (32,42) comprising an endless chain of steel cylindrical rollers (32R,42R) arranged to run along to recirculate a closed path (32P,42P) around a steel tread element (32G,42G) and a steel central body (32B,42B) of the assembly (32,42), which central body to the load-carrying housing (32H,42H) is attached or forms an integral part thereof, the track (32P,42P) comprising: - a working section (32Pw,42Pw) defined by a flat, load-bearing surface (32L,42L) of the steel tread element (32G,42G) of the assembly (32,42), in which working section (32Pw,42Pw) an active set of the cylindrical rollers (32R,42R) engages the rail (31,41), and - a return section (32Pr,42Pr) defined by a return surface (32T,42T) of the steel central body (32B,42B) of the assembly (32,42) in which a remaining set of cylindrical rollers (32R,42R) is clear of the rail (31,41), where for example, the return section has a section parallel to the working section (32Pw,42Pw), the assembly (32,42) comprising an elastically compressible resilient insert (321,42!) containing, for example, a plastic, which resilient insert is located between the steel central body (32B,42B) and the steel tread element (32G,42G) is above the working part (32Pw,42Pw) so that the central body (32B,42B) is resiliently supported on the working set of cylinder rollers (32R,42R) through the insert (321,421) and the steel tread element (32G,42G).

An assembly (32,42) according to claim 1, wherein the resilient insert (321,42) is manufactured from a composite material, e.g. a fibre-reinforced plastic material.

An assembly (32,42) according to claim 2 or 2, wherein the tread element (32G,42G) and/or the resilient insert (321,42) are each embodied in the form of a plate.

An assembly (32,42) according to one or more of the preceding claims, wherein the tread element (32G,42G) and the resilient insert (321,421) are both embodied in the form of a plate, and the tread element (32G,42G) has a thickness smaller than, e.g. corresponding to about 55-65% of, a thickness of the tread element (32G,42G).

An assembly (32,42) according to any of the preceding claims, wherein the central body (32B,42B) has a recess in which the resilient insert (321,421) and the tread plate (32G,42G) are located and axially enclosed , e.g. such that the tread plate (32G,42G) is flush with the longitudinally adjacent run-back surface (32T,42T) of the central body (32B,42B).

An assembly (32,42) according to one or more of the preceding claims, wherein at a front and rear side of the load bearing surface (32L,42L), the return surface extends upwardly directly from the load bearing surface (32L,42L), preferably wherein a front and/or rear section of the tread element (32G,42G) extends slightly inclined upwardly towards the run-back surface.

An assembly (32,42) according to any one of the preceding claims, further comprising a second endless chain of linear recirculating cylindrical rollers (32R,42R) arranged to recirculate along a second closed track (32P,42P) which defined by the assembly, the two tracks (32P,42P) being laterally adjacent and parallel to each other, the second track (32P,42P) comprising a working portion (32Pw,42Pw) passing through a second load bearing surface of a second tread element is defined and in which an operative set of the cylindrical rollers (32R,42R) engages the rail (31,41), and a retraction portion (32Pr,42Pr) passing through a second retraction surface of the central body (32B,42B) is defined and in which a receding portion of the cylindrical rollers (32R,42R) is clear of the rail (31,41), the central body being resiliently supported on the respective working portions of the cylindrical rollers of both e endless chains through the respective tread elements, wherein a second elastically compressible resilient insert, e.g. comprising a plastic material, is located between the central body (32B,42B) and the second tread element.

An assembly (32,42) according to one or more of the preceding claims, wherein the housing (32H,42H) is provided with one or more seals, at least around the working portion of the recirculating cylindrical rollers (32R,42R). (32S,42S), e.g. between one or more bottom surfaces of the assembly, e.g. bottom surfaces of walls (32W,32We,42W,42We) of the assembly collectively enclosing the working portion, and the top surface (315,41S) of the rail (31,41), with the seals (32S,425S), e.g. together with the walls (32W,32We,42W,42We}, between the load bearing surface (32L,42L) and the top surface of the rail (31, 41) define a grease chamber (32H,42H) for the working set of the recirculating cylindrical rollers (32R,42R), e.g. wherein the seals (31S,32S) are substantially V-shaped in a cross-section thereof.

An assembly (32,42) according to one or more of the preceding claims, wherein the housing (32H,42H) is on a front and/or rear side, facing a longitudinal direction of the rail (31,41), and on a longitudinal distance from the working part (32Pw,42Pw), is provided with one or more front and/or rear scrapers (32C,42C) and/or brushes, respectively, which clean the upper surface (31S,41S) of the rail (31,41 ) to clean the rail (31,41).

An assembly (32,42) according to any one of the preceding claims, wherein the housing (32H,42H) comprises a front and rear vertical end wall (32We,42We) located laterally at the front and rear of the assembly, respectively. extend, and a front and rear guide wall (32Wg,42Wg) respectively attached to the front and rear end wall (32We,42We) and respectively a front and rear section of the return section of the closed track (32P,42P) opposite the return surface (32T,42T), e.g. where the attachment is effected via one or more elongated fasteners, e.g. one or more bolts, screws, or the like, extending perpendicularly through the end walls and projecting longitudinally into the guide walls.

An assembly (32,42) according to at least claims 6 and 9, wherein the housing (32H,42H) comprises a second front guide wall and a second rear guide wall, which are attached to the front and rear end walls (32We,42We) respectively. attached and respectively define a leading and trailing section of the return portion of the second closed trajectory (32P,42P) opposite the second return surface (32T,42T).

An assembly (32,42) according to at least claim 9, wherein the housing (32H,42H) further comprises a front and/or rear frame extending from the front and/or rear end wall (32We,42We) respectively in a forward and/or and/or protrude rearwardly, the front and/or rear scraper (32C,42C) being attached below the respective frame at a longitudinal end thereof.

An assembly (32,42) according to one or more of the preceding claims, wherein the cylindrical rollers (32R,42R) each rotate about a respective roller axis (32A,42A) with major ends (32E,42E) over respective raceways ( 32D,42D) barrels formed by vertical projections from the central body (32B,42B) extending longitudinally along the closed trajectory (32P,42P) on respective lateral sides of the closed trajectory (32P,42P).

An assembly (32,42) according to any one of the preceding claims, further comprising left upper and lower and right upper and lower longitudinal wall members (32W1,42WI1) extending upper and lower vertical projections from the central body (32B,42B ) forms at the left and right ends thereof, and which extend longitudinally at least a length of the closed trajectory (32P,42P), e.g. the left upper and lower wall portions {32W,42Wl) are interconnected, and the right upper and lower wall members (32W,42W) are interconnected, via one or more elongated fasteners (32M,42M), e.g. one or more bolts, screws or similar, located vertically within the respective upper and lower longitudinal wall members (32W ,42Wl) and extending through the respective lateral end of the central body (32B,42B), e.g. with a plurality of elongated fasteners (32M,42M) extending longitudinally along the wall sections n (32WI,42WI) are distributed.

An assembly (32,42) according to at least claim 7 and claim 12, further comprising intermediate upper and lower longitudinal wall members (32Wi,42Wi} forming upper and lower vertical projections from the central body (32B,42B) between the two closed trajectories (32P,42P), and which extend longitudinally over at least a length of the closed trajectory (32P,42P), e.g. the intermediate upper and lower wall parts (32Wi,42Wi) are interconnected via one or more elongated fasteners (32M,42M), e.g. one or more bolts, screws or the like, extending vertically within respective upper and lower longitudinal wall portions (32W,42W) and through a central portion of the central body (32B,42B) , e.g. wherein a plurality of elongate fasteners (32M,42M) are distributed longitudinally along the wall portions (32Wi,42Wi).

An assembly (32,42) according to at least claim 10 and claim 14 or 15, wherein the longitudinal wall portions (32W1,32Wi,42W1,42Wi) are connected to the end walls (32We,42We) via one or more elongated fasteners extending extend perpendicularly through the end walls (32We,42We) and insert longitudinally into the longitudinal wall members (32W,32Wi,42W,42Wi).

17. Use, on board a vessel (5), of an assembly (32,42) comprising an endless chain of linear recirculating cylindrical rollers (42R,42R) for supporting an object (2,3) on a rail (31,41) attached to the vessel, e.g. to a deck (52) thereof, and simultaneously moving the object (2,3) along the rail (31,41) in an X-Y plane of the vessel, e.g. an assembly (32,42) according to one or more of the preceding claims.

18. System of one or more rails (31,41) suitable or adapted to be attached to an offshore vessel (5), e.g. to a deck (52) thereof, and one or more assemblies (32,42) for supporting an object (2,3) on the one or more rails (31,41) as the object moves along the one or more rails (31,41), each assembly (32,42) carrying a load-carrying body (32B, 42B) has for supporting the object (2,3), each assembly (32,42) having an endless chain of steel cylindrical rollers (32R,42R) arranged to recirculate along a closed track (32P,42P) around a steel tread element (32G,42G) and a steel central body (32B,42B) of the assembly (32,42), which central body is attached to or forms an integral part of the load-carrying housing (32H,42H), wherein the track (32P,42P) includes: - a working section (32Pw,42Pw) defined by a flat, load-bearing surface (32L,42L) of the steel tread element (32G,42G) of the assembly (32,42), in which working portion (32Pw,42Pw) an active set of the cylindrical rollers (32R,42R) engages the rail (31,41), and - a retraction portion (32Pr,42Pr) defined by a retraction surface ( 32T,42T) of the steel central body (32B,42B) of the assembly (32,42) in which a remaining set of cylindrical rollers (32R,42R) is clear of the rail (31,41), with the return portion e.g. a section which is parallel to the working part (32Pw,42Pw).

A system according to claim 18, wherein the assembly (32,42) comprises an elastically compressible resilient insert (321,421), e.g. containing a plastic, said resilient insert being located between the steel central body (32B,42B) and the steel tread element ( 32G,42G) is above the working section (32Pw,42Pw) so that the central body (32B,42B) is resiliently supported on the working set of cylinder rollers (32R,42R) via the insert (321,421) and the steel tread element (32G,42G ).

A system according to claim 18 or 19, wherein each assembly (32,42) is according to one or more of claims 1-16.

21. Construction for supporting an object (2,3) on a vessel (5), comprising

- a first system according to one or more of claims 18-20, of which the one or more rails are one or more first rails (31) extending in a first direction (X), and the one or more assemblies are one or more first assemblies (32), - a second system according to one or more of claims 18-20 of which the one or more rails are one or more second rails (41) extending in a second direction (Y), and the one or more assemblies being one or more second assemblies (42), the structure arranged to support the object (2,3) via the one or more first assemblies (32) on the one or more first rails (31), and the one or more more first rails (31) are supported on the one or more second rails (41) via the one or more second assemblies (42), so that the object (2,3) is in both the first and second directions (X,Y) is movable along the rails (31,41), preferably wherein the first direction (X) is perpendicular to the second direction (Y), e.g. wherein the c The construction also comprises a positioning frame (4), via which the one or more first rails (41) is supported on the one or more second assemblies (42), so that the first system, and thus the object (2,3), can be moved over the one or more second rails is movable by moving the positioning frame (4) over the one or more second rails (41).

A structure for supporting the object (2,3) on a vessel (5), comprising: - a first system according to one or more of claims 18-20, the one or more rails of which comprise one or more first rails (31) are extending in a first direction (X), and the one or more assemblies are one or more first assemblies (32), - a second system according to one or more of claims 18-20, of which the one or more rails have one or more are second rails (41) extending in a second direction (Y), and the one or more assemblies are one or more second assemblies (42), the one or more first rails crossing over the one or more second rails at one or more crossings, and wherein the one or more first rails (31) at each crossing are supported on the one or more second rails (42) via a unit (3242) comprising a first assembly (32) in an upper portion of the unit and a second assembly (42) in a lower portion of the unit, the working portion e (32Pw) of the first assembly (32) engages the first rails (31), e.g. such working portion (32Pw) forms an upper portion of the closed track (32P) of the first assembly (32), and wherein the working portion (42Pw) of the second assembly (42) engages the second rail (41), e.g. such working portion (42Pw) forms a lower portion of the closed trajectory (42P) of the second assembly (42), so that the object (2,3), connected to the one or more first rails (31), is movable along the rails (31,41) in both the first and second directions (X,Y), preferably the first direction (X ) is perpendicular to the second direction (Y).

23. Combination (1) of an object (2,3) and a system according to one or more of claims 18-20, or a construction according to claim 21 or 22, wherein the object (2,3) is a tool for handling an offshore structure, e.g. an elongated offshore structure, e.g. wherein the tool is a pile holding tool (2,3) for handling a pile (6), e.g. a pile (6) adapted to support an offshore wind turbine the combination further comprising one or more actuators (43) for moving the tool (2,3) over the one or more rails (31,41), and thus relative to the vessel (5), if attached to the vessel.

A combination (1) according to claim 23, wherein the device (2,3) is resiliently mounted on the one or more assemblies (32,42).

A combination (1) according to claim 23 or 24, arranged for holding a pile (8) on a vessel (5), e.g. a pile (6) adapted to support an offshore wind turbine, e.g. holding the pile during installation of the pile (6) at an offshore location next to the vessel, the object being a pile holding tool (2,3) comprising: - a support structure (3) mounted on the one or more assemblies (31, 41), - a pole holder (2) attached to the support structure, the pole holder comprising a ring (21), and the pole holder (2) being adapted to support the pole with said ring (21) in at least a vertical orientation. the ring (21) comprising a plurality of pole engaging devices (22) distributed around the circumference of the ring (21), each pole engaging device (22) being adapted to engage an outside of a pole (6) extending through the ring {21) extends, e.g. each pile engaging device (22) has one or more pile guide rollers includes.

A combination according to any one of claims 23-25, wherein the combination (1) is a combination of an offshore structure handling tool, e.g. the pile holding tool according to claim 24, and the structure according to claim 21, wherein the construction further comprises a positioning frame (4), via which the one or more first rails (31) are mounted on the one or more second assemblies (42), so that the first system, and thus the object (2,3), is movable over the one or more second rails by moving the positioning frame (4) over the one or more second rails (41), and wherein, for moving the tool (2,3) in the second direction, the actuators move the positioning frame ( 4) so as to move the positioning frame (4), and with it, the first system and the tool (2,3), over the one or more second rails (41), and wherein, for moving the tool {2 ,3) in the first direction, the actuators engage the tool (2,3), so as to moving the tool (2,3) over the one or more first rails (31).

A combination (1) according to claim 26, wherein the combination (1) is arranged, when the combination (1) is mounted on the vessel, to maintain a predetermined X-Y location of the pole holder (2,3) independent of the movement of the vessel, e.g. with the vessel in floating condition, by moving it, by the actuators, over the one or more first rails (31) and the one or more second rails (41), and thus relative to the vessel, causing the pole holder (2,3) to move.

A combination (1) according to claim 27, comprising an active motion-compensating propulsion system for moving the support structure (3) over the rails (31,41), and thus relative to the vessel, the active motion-compensating propulsion system for moving the one or more comprises actuators, the actuators comprising a first actuator, e.g. a cam track attachable to the deck of the vessel and a drive attached to the positioning frame (4) and engaging the cam track, for moving the positioning frame (4 ) over the one or more first rails, and a second actuator, e.g. a cam track attached to the support structure (3) and a drive attached to the positioning frame (4) and engaging the cam track, to move the support structure (3) to move along the one or more second rails, the drive system having an active wave-induced motion compensation mode in which the drive system is operated to provide a predetermined predetermined X-Y location of the pile holding tool (2,3) independent of the movement of the vessel.

A combination (1) according to any of claims 23-26, wherein the ring (21) comprises a ring base and one or more movable jaws (23), e.g. two semi-circular jaws,

each jaw being movable between a closed position, the ring (21) forming a closed annulus, and an open position.

30. Vessel, e.g. a vessel for handling an offshore structure, e.g. a pile (6), at an offshore location, e.g. for installing the structure at the offshore location, equipped with: - at least one system according to one or more of claims 18-20, wherein the one or more rails (31,41) are attached to the vessel, e.g. more second rails (41) are attached to the vessel, e.g. are deck mounted rails, and preferably the first direction (X) is an X direction of the vessel and the second direction (Y) is a Y direction of the vessel, and/or - at least one combination (1) according to one or more of claims 23-29, wherein the one or more rails (31), i.e. the one or more first rails (31), if present, are fixed to the vessel, e.g. rails (31) mounted to the deck, and where present, preferably the one or more first rails (31) extend in the X direction of the vessel and the one or more second rails (41) in the Y direction of the vessel.

Vessel (5) according to claim 30, provided with the combination (1) according to claim and optionally one or more of claims 26-29, wherein the pile holding tool (2,3) is movable along the one or more rails (31, 41) between a stowed position (fig. 1a) in which the ring (21) of the pole holder, viewed in the X-Y plane of the vessel, extends within a contour of the vessel, and an active position (fig. 1b) in which the ring (21) of the pole holder extends outboard of the vessel as viewed in the X-Y plane of the vessel.

A method of handling an object (2,3) on a vessel, using a vessel according to claim 30 or 31.

33. Method for handling an object (2,3) on a vessel, comprising: - supporting an object (2,3) on one or more rails (31,41) attached to the vessel, via one or more assemblies (32,42) each comprising an endless chain of recirculating cylindrical rollers (32R,42R), e.g. wherein the assemblies are each according to any of claims 1-16,

- moving the object (2,3) along the one or more rails (31,41) and therewith, relative to the vessel, the moving for one or more of the assemblies (32,42) recirculating the involves an endless chain of linear recirculating cylindrical rollers (32R,42R) along a closed trajectory (32P,42P) defined by each assembly (32,42P), with an operative set of the cylindrical rollers (32R,42R) engaging the rails and moving in a direction opposite to the movement of the object (2,3).

A method according to claim 32 or 33, wherein - the one or more rails (31,41) comprise one or more first rails (31) extending in a first direction (Y), and one or more second rails (41) extending in a second direction at an angle to the first direction (X), - the one or more assemblies comprise one or more first assemblies (32), and one or more second assemblies (42), the object (2, 3) is supported on and moves across the one or more first rails (31) via the one or more first assemblies (31), and the one or more first rails (31) are supported on and move across the one or more second rails (41) via the one or more second assemblies (42), so that the object (2,3) is movable along the rails (31,41) in both the first and second directions (X,Y), wherein, preferably, the second direction (X) is perpendicular to the first direction (Y), and wherein the one or more rails and assemblies, and therewith the object (2,3), along the one or more second r rails (41) are moved by moving a positioning frame (4), via which the one or more first rails (31) are mounted on the one or more second assemblies (42), along the one or more second rails (2).

A method according to claim 33 or 34, wherein the movement of the object (2,3) is driven, e.g. such as to compensate for movements of the vessel in the X-Y plane of the vessel.

A method according to claim 35, wherein the object is a pile holding tool (2,3), and supporting the object comprises supporting a support structure on the one or more rails, i.e. on the first rails (31), if any (3) of the pile holding tool (2,3), with the support structure (3) mounted on the one or more assemblies (31,41),

i.e. the one or more first assemblies, if any, supporting a pole holder (2) with a ring (21) extending outboard of the vessel, the method further comprising:

- holding a pole, e.g. a pole adapted to support a wind turbine, such that it extends in a vertical orientation through the ring (21) of the pole holder (2) of the pole holder tool (2,3), wherein pole-engaging devices (22) distributed around the periphery of the ring (21) engage the outside of the pole, and - lowering the pole into a body of water on which the craft floats, while the pole is held and guided by the pole-engaging devices ( 22), whereby the motion compensation is performed at least during the lowering of the post.

A method according to claim 36, wherein the movement of the pole holding tool (2,3) is further actuated to include: - before at least lowering the pole, moving the pole holder (2,3) from a stowed position (fig.1a), in which a ring (21) of the pole holder (2) extends within the contour of the vessel, viewed in the X-Y plane of the vessel, to an operative position (fig.1b}), in which the ring (21) of the vessel, viewed in the X-Y plane of the vessel, extends outboard of the vessel, and/or - after at least lowering the pole and detaching the pole from the pole holder (2 ), including releasing the pole engaging devices (22) from the pole, moving the pole holder (2,3) from the operative position (fig. 1b) to the stowed position (fig. 1a).