US-20260125245-A1 - LIFTING SYSTEM FOR LIFTING A MONOPILE, A CRADLE, A VESSEL AND A METHOD OF STORING A MONOPILE ON A VESSEL

US20260125245A1US 20260125245 A1US20260125245 A1US 20260125245A1US-20260125245-A1

Abstract

A lifting system ( 1 ) for lifting a monopile ( 3 , 6 ) comprises a pair of coupling members ( 2 ) for being coupled to a monopile at a distance from each other in longitudinal direction of the monopile. Each of the coupling members has a support ( 7 ) for being coupled to a hoisting apparatus, such as a crane ( 21 ), a sling ( 8 ) for at least partly surrounding a monopile, which sling is suspended from the support thus forming a loop and a tightening device ( 14 ) for varying the length of the sling.

Inventors

Quintus Wilhelmus Petrus Maria Zuijdgeest
David Goedknegt

Assignees

IQIP HOLDING B.V.

Dates

Publication Date: 20260507
Application Date: 20230921
Priority Date: 20221006

Claims (20)

1 . A lifting system for lifting a monopile, comprising: a pair of coupling members configured to be coupled to a monopile at a distance from each other in a longitudinal direction of the monopile, wherein each of the coupling members comprises: a support configured to be coupled to a hoisting apparatus; a sling configured to at least partly surround the monopile, which sling is suspended from the support thus forming a loop; and a tightening device configured to vary a length of the loop.
2 . The lifting system according to claim 1 , wherein the coupling members are separate units.
3 . The lifting system according to claim 1 , wherein each sling is mounted or releasably mountable to the respective support at a first location and a second location thereof, which first and second locations are located at a distance from each other.
4 . The lifting system according to claim 3 , wherein each sling comprises an endless element which is looped about the respective support at the first location and at the second location.
5 . The lifting system according to claim 4 , wherein at the second location each sling is looped about two stationary sling guides which are located at a distance from each other in a plane, wherein each tightening device comprises a dynamic sling guide configured to guide the respective sling between the respective stationary sling guides, wherein the dynamic sling guide is movable with respect to the respective stationary sling guides in a transverse direction of the respective plane.
6 . The lifting system according to claim 5 , wherein at the first location each sling is looped about two stationary sling guides which are located at a distance from each other.
7 . The lifting system according to claim 1 , wherein each support is rigid.
8 . The lifting system according to claim 1 , wherein each support is an elongate element.
9 . The lifting system according to claim 1 , wherein the lifting system is provided with a hoisting member configured to be coupled to a hoisting apparatus, which hoisting member is releasably attachable to the supports.
10 . The lifting system according to claim 9 , wherein the hoisting member comprises a rectangular frame having two opposite sides which are releasably attachable to the respective supports.
11 . A cradle for receiving a monopile lifted by a lifting system comprising a pair of coupling members configured to be coupled to the monopile at a distance from each other in a longitudinal direction of the monopile, wherein each of the coupling members comprises a support configured to be coupled to a hoisting apparatus and a sling configured to at least partly surround the monopile, which sling is suspended from the support thus forming a loop, wherein the cradle comprises a frame with cooperating receivers configured to fit the supports.
12 . The cradle according to claim 11 , wherein the receivers for each support comprise a first pair of hooks and a second pair of hooks spaced apart from the first pair of hooks.
13 . A vessel, comprising: a deck; a cradle movable across the deck, the cradle being configured to receive and support a monopile. wherein the cradle includes receivers; and a lifting system for lifting the monopile, comprising: a pair of coupling members configured to be coupled to the monopile at a distance from each other in a longitudinal direction of the monopile, wherein each of the coupling members comprises: a support configured to be coupled to a hoisting apparatus: a sling configured to at least partly surround a monopile, which sling is suspended from the support thus forming a loop; and a tightening device configured to vary a length of the loop.
14 . The vessel, according to claim 13 , wherein the cradle is movable in a longitudinal direction and a lateral direction of the deck.
15 . A method of storing a monopile on a vessel using a cradle with receivers and a lifting system having a pair of coupling members, wherein each of the coupling members has a support and a sling to at least partly surround the monopile, the method comprising: mounting each sling around the monopile and attaching each sling to the respective support, the slings being at a distance from each other along the monopile and forming respective loops about the monopile; shortening each of the loops of the slings until distances between the supports and the monopile are at desired distances; connecting a hoisting member to the supports; lifting and transferring the supports including the slings and the monopile and to the cradle with the hoisting member where the supports are placed at the receivers; and disconnecting the hoisting member from the supports.
16 . The method according to claim 15 , wherein mounting each sling comprises mounting each sling to the respective support at a first location and a second location thereof, which first and second locations are located at a distance from each other, and wherein at the second location each sling is looped about two stationary sling guides which are located at a distance from each other in a plane, and wherein shortening comprises moving a dynamic sling guide that engages a portion of each respective sling between the respective stationary sling guides in a transverse direction to each respective plane.
17 . The vessel according to claim 13 , wherein each sling is mounted or releasably mountable to the respective support at a first location and a second location thereof, which first and second locations are located at a distance from each other.
18 . The lifting system according to claim 17 , wherein each sling comprises an endless element which is looped about the respective support at the first location and at the second location.
19 . The lifting system according to claim 18 , wherein at the second location each sling is looped about two stationary sling guides which are located at a distance from each other in a plane, wherein each tightening device comprises a dynamic sling guide configured to guide the respective sling between the respective stationary sling guides, wherein the dynamic sling guide is movable with respect to the respective stationary sling guides in a transverse direction of the plane.
20 . The lifting system according to claim 19 , wherein at the first location each sling is looped about two stationary sling guides which are located at a distance from each other.

Description

CROSS-REFERENCE TO RELATED APPLICATIONS This Application is a Section 371 National Stage Application of International Application No. PCT/NL2023/050488, filed Sep. 21, 2023 and published as WO 2024/076231 A1 on Apr. 11, 2024, in English. BACKGROUND The present invention relates to a lifting system for lifting a monopile. Offshore wind turbines may be installed on top of monopiles which are driven into the seabed. Usually, the monopiles are manufactured at an onshore location and loaded to a vessel at a quay. The monopiles are transferred from the quay to the vessel by means of a crane and stored in a horizontal orientation on a deck of the vessel. The crane has hoisting cables from which a spreader beam is suspended. Prior to lifting a monopile, two slings are connected around the monopile and the slings are attached to the spreader beam. After the monopile is placed onto the deck the slings are disconnected from the monopile and connected to another monopile that will be transferred from the quay to the vessel. After placing the monopiles on the deck, the vessel sails to an offshore site where the monopiles will be installed into the seabed. At the offshore site a crane on the vessel can lift a stored monopile after connecting the same spreader beam or a different one including the two slings or different ones to it and transfer it to an upending device which is used to turn the monopile to a vertical orientation. Subsequently, the monopile may be displaced to a location of the vessel where the monopile is lowered to the seabed and driven into the seabed by means of a pile driver. A disadvantage of the above-described operations is that they take a lot of time at the offshore site. SUMMARY A lifting system for lifting a monopile comprises a pair of coupling members for being coupled to a monopile at a distance from each other in longitudinal direction of the monopile, wherein each of the coupling members has a support for being coupled to a hoisting apparatus, such as a crane, a sling for at least partly surrounding a monopile, which sling is suspended from the support thus forming a loop and a tightening device for varying the length of the loop. An advantage of the lifting system according to the invention is that the coupling members are relatively simple mechanical structures which can be connected to a monopile before loading it to a vessel, for example at a quay, and can remain on the monopile until it is placed on an upending device of the vessel. The supports can be used to be temporarily fixed to the vessel such that the monopile hangs from the supports by the slings, for example during transport of the monopile to an offshore site. The tightening device provides the opportunity to clamp the sling about a monopile by shortening the length of the loop. This means that the coupling members may function as sea fastening tools. At the offshore site the monopile can be easily lifted by connecting a hoisting member to the supports, hence obviating time-consuming operations of fastening slings to each of the monopiles. The support and the sling of the coupling member may be adapted such that when shortening the loop the monopile is clamped against the support. The coupling members may be separate units. The sling may be mounted or releasably mountable to the support at a first location and a second location thereof, which first and second locations are located at a distance from each other. This means that a monopile may be clamped between the sling and the support at each of the coupling members when shortening the loop of the sling. The sling may comprise an endless element which is looped about the support at the first location and at the second location. In this case the loop of the sling, i.e. a portion of the endless element that can support a monopile, is formed by two sections of the sling. In a particular embodiment at the second location the sling is looped about two stationary sling guides which are located at a distance from each other in a plane, wherein the tightening device comprises a dynamic sling guide for guiding the sling between the stationary sling guides, wherein the dynamic sling guide is movable with respect to the stationary sling guides in transverse direction of the plane. The dynamic sling guide may be operated by an actuator. The stationary sling guides may be pins. At the second location the sling may be looped about two stationary sling guides which are located at a distance from each other. The stationary sling guides at the second location may be pins. The support may be rigid. The support may be an elongate element, for example a beam made of steel. The lifting system may be provided with a hoisting member for being coupled to a hoisting apparatus, which hoisting member is releasably attachable to the supports, In case the coupling members are separate units, they are preferably applied on a monopile at a fixed distance from each other, since the hoisting member may hav