Steering line system for a crane and method for controlling a load lifted with a crane

Abstract

The present disclosure relates a steering line system for controlling a load (50) lifted by a crane (200) having a boom (100) elongating along a longitudinal axis (L). The steering line system comprises at least a first, second, third and fourth winch-driven steering line (11, 12, 13, 14) suspendable between the boom and the load or between the boom and a load supporting device (55) supporting the load, a first suspension member (21) and a second suspension member (22) for coupling respectively the first and second winch-driven steering line to the boom, first moving means (30a) configured for moving the first and second suspension member along a first longitudinal section (B1) of the boom, a third suspension member (23) and a fourth suspension member (24) for coupling respectively the third and fourth steering line to the boom, second moving means (30b) configured for moving the third and fourth suspension member along a second longitudinal section of the boom (B2), different from the first longitudinal section. The present disclosure also related to a method for controlling a load during lifting with a crane comprising horizontal and vertical control of the load.

Description

[0001] P137980PC00

[0002] Title: Steering line system for a crane and method for controlling a load lifted with a crane

[0003] Field of disclosure

[0004] The present invention relates to a steering line system used in conjunction with a crane, more specifically a steering line system for controlling a load being lifted by a crane, and wherein the crane comprises a crane boom. The present disclosure also relates to a method for controlling the load lifted with the crane.

[0005] Background

[0006] Boom-type of cranes for lifting large loads are used in various industries such as for example in the off shore industry and the oil and gas industry.

[0007] The offshore wind industry has seen significant growth, driven by the increasing demand for renewable energy sources. Central to the construction of offshore wind farms is the erection of the wind turbines. For instance jack-up vessels equipped with large cranes may be used for the assembly and / or maintenance of the wind turbines.

[0008] Typically, the cranes used for lifting the wind turbine components comprise a crane boom coupled to a rotatable platform that is supported by a crane base. These cranes are tasked with the critical operations of lifting, transporting, and installing wind turbine components such as blades, nacelles, and tower sections. Ensuring the stability and precise positioning of these components during lifting operations is paramount to the safety and efficiency of the installation process.

[0009] To control and stabilize the load during these operations, cranes having a boom typically employ a steering line system.

[0010] Conventional steering line systems often utilize guidewires suspended and tensioned between a top and bottom traverse. For each side of the crane boom, a steering line is connected to the lifted load via a snatchblock which itself is mounted on the guidewire. The passively traveling snatchblock along the guidewire allows the steering line to follow the lifted load in the horizontal plane during hoisting.

[0011] Additionally, a pair of stabilizer lines may be connected directly to the load usually from the rotating platform mounted on the crane base or from the boom head.

[0012] With such a conventional arrangement, the steering lines are used to control the lifted load in the horizontal plane and the stabilizer lines are used to control the load in the vertical plane. Therefore, these conventional steering line systems allow the operator to counteract unwanted rotations and translations of the load.

[0013] However, as the offshore wind market evolves, the operational requirements for these steering line systems evolve accordingly. One of the major drawbacks of the existing conventional guidewire-based steering line systems is the lack of stiffness and therefore it is incapable of providing sufficient control of the lifted load in certain suboptimal situations. This lack of stiffness becomes increasingly problematic with longer crane booms and with large loads — a trend that is prevalent in the industry as larger wind turbines are being installed at greater heights.

[0014] To address these limitations of the conventional steering line systems, there has been a shift towards the development of next- generation steering line systems that interface directly with the crane boom, as opposed to relying on guidewire-based setups.

[0015] However, additional challenges remain, for instance challenges related to the complex nature of offshore lifting operations which typically consist of three distinct stages: 1) pickup of the item from the storage position of the vessel, 2) transportation of the item to the installation location, and 3) installation of the lifted item.

[0016] Each of these stages has particular requirements when it comes to position accuracy and stability of the load. Consequently, it is inherently difficult to create a single, integrated steering line system that functions optimally during all 3 stages.

[0017] Existing steering line systems are often optimized for one or two stages at the expense of the others. For instance, a system designed to optimize load control during the installation stage may have limited efficacy during the pickup stage, and vice-versa a system designed to optimize load control during the pick-up stage may not be optimum for use during the installation stage.

[0018] Hence, there is room for improving steering line systems for large cranes, e.g. offshore cranes, in particular improved steering line systems that can deliver load stability and control throughout the entire lifting process, from pickup to installation.

[0019] Summary

[0020] It is an object of the present disclosure to provide a steering line system for controlling a load lifted by a crane that overcomes the limitations of the present steering line systems as outlined above, more particularly, it is an objective to provide a robust and versatile steering line system that is optimally operational at all installation stages of for instance a wind turbine.

[0021] The present disclosure is defined in the appended independent claims. The dependent claims define advantageous embodiments.

[0022] According to a first aspect of the present disclosure, a steering line system for controlling a load lifted by a crane having a boom elongating along a longitudinal axis is provided.

[0023] The steering line system comprises at least a first, second, third and fourth winch-driven steering line suspendable between the boom and the load or between the boom and a load supporting device supporting the load, a first suspension member and a second suspension member for coupling respectively the first and second winch-driven steering line to the boom, and first moving means configured for moving the first and second suspension member along a first longitudinal section of the boom such that a height of the first and second suspension member with respect to a base level of the crane is adjustable by moving the first and second suspension members along the first longitudinal section of the boom.

[0024] The steering line system further comprises a third suspension member and a fourth suspension member for coupling respectively the third and fourth steering line to the boom, second moving means configured for moving the third and fourth suspension member along a second longitudinal section of the boom, different from the first longitudinal section, preferably adjacent to the first longitudinal section, such that a height of the third and fourth suspension member with respect to the base level of the crane is adjustable by moving the third and fourth suspension members along the second longitudinal section of the boom.

[0025] Advantageously, by providing two movable suspension members on the first longitudinal section of the boom and two additional moveably suspension members on the second section of the boom together with associated steering lines, horizontal and vertical load control can optimally be obtained over the entire height range of the crane. Indeed, in a first lifting phase when the load is below a reference height, the suspension members and associated steering lines of the first boom section may be used for a horizontal control of the load and the suspension members and associated steering lines of the second boom section may be used for a vertical control of the load. When the height of the load increases, the horizontal-vertical control may be switched and in a second lifting phase, the suspension members and associated steering lines of the first boom section may be used for a vertical control of the load and the suspension members and associated steering lines of the second boom section may be used for a horizontal control of the load.

[0026] Advantageously, a horizontal and vertical load steering can be performed over the entire crane height range without having to de-connect and reconnect equipment such as steering line cables.

[0027] Advantageously, the same steering line system, i.e. the at least four steering lines and associated four moveable suspension members, can be used for different offshore lifting operations at different stages, including pickup of the item from the storage position of the vessel, transportation of the item to the installation location, and installation of the lifted item.

[0028] Typically, each of the suspension members may comprise any of or a combination of: one or more pulleys, one or more sheaves, one or more cableguiding elements, one or more hooks or any other element suitable for coupling a winch-driven steering line to the boom.

[0029] The steering line system according to the present disclosure is however not limited to four steering lines. In addition to the four steering lines, further steering lines may be provided and for example be coupled to any of the boom, the slewing platform, the first or second moving means or a further moving means. For example, optionally, a fifth and a sixth steering line may be provided, and additionally a fifth and sixth suspension member may be provided for coupling the fifth and sixth steering lines to the boom. In embodiments, the second moving means may be configured for moving the fifth and sixth suspension member along the second longitudinal section of the boom.

[0030] The first and the second longitudinal section of the boom may correspond to respectively a lower part and an upper part of the boom. The two longitudinal sections may overlap or may not overlap.

[0031] Generally, the steering line system may comprise a controller configured for controlling a movement and / or position of the first and second suspension member along the first longitudinal section of the boom, and for controlling a movement and / or position of the third and fourth suspension member along the second longitudinal section of the boom. The controller may further be configured for controlling any of a suspension length, a tension and / or a force of the at least first, second, third and fourth winch-driven steering lines.

[0032] Additionally, the steering line system may comprise a first, second, third and fourth steering line winch associated to respectively the first, second, third and fourth winch-driven steering line, and wherein each winch is configured for controlling a suspension length between the boom and the load and / or for controlling a tension strength in the steering line. Optionally, a fifth and sixth steering line winch associated to the fifth and sixth steering line may be provided.

[0033] The first moving means may comprises one or more trolleys or one or more carriages for moving the first and second suspension member along the first longitudinal section of the boom. Optionally, wherein the first moving means comprise a first trolley for moving the first suspension member and a second trolley for moving the second suspension member. Preferably wherein each of the first and second trolley comprises any of a pulley, a sheave or any other suitable element for forming respectively the first and second suspension member.

[0034] The second moving means may comprise a carriage or one or more trolleys for moving the third and fourth suspension member along the second longitudinal section of the boom. Optionally, the second moving means comprise a carriage supporting a traverse member of a traverse beam and wherein a first end and a second end of the traverse member or traverse beam is forming the third and fourth suspension member, preferably wherein the first and second end are provided with a pulley or a sheave.

[0035] Generally, the motion of the first and second suspension member along the first section of the boom is independent from the motion of the third and fourth suspension member along the second section of the boom.

[0036] Optionally, the motion of the first suspension member is independent of the motion of the second suspension member and / or wherein the motion of the third suspension member is independent of the motion of the fourth suspension member.

[0037] Generally, the motion of any of the suspension members is independent of the motion of the load lifted by a hoist assembly of the crane.

[0038] The present disclosure further relates to a crane comprising a boom elongating along a longitudinal axis, a hoist assembly coupled to the boom for lifting a load, and a steering line system as presently disclosed. The crane may for example be a platform crane and / or an offshore crane.

[0039] Typically, the boom is pivotable around a boom pivot axis perpendicular to the longitudinal axis of the boom.

[0040] The boom generally comprises a first longitudinal section and a second longitudinal section, and wherein the first longitudinal section is provided with one or more guiding members for guiding the first moving means while moving the first and second suspension member along the first longitudinal section of the boom. The second longitudinal section may be provided with one or more further guiding members for guiding the second moving means while moving the third and second coupling member. The one or more guiding members may for example comprise one or more rails. Alternatively, the one or more guiding members may comprise a skid / sliding surface.

[0041] The rails may optionally be coupled to chords of the boom, e.g. two spaced rails may be coupled to two spaced chords of the boom.

[0042] The first longitudinal section of the boom may for example comprise two rails spaced from each other and configured for guiding respectively a first and a second trolley, and wherein the second section of the boom may comprise one or more further rails configured for guiding a carriage supporting a traverse member or a traverse beam.

[0043] In other embodiments, the boom may comprise one or more rails extending at least along the first and the second section of the boom such that the same one or more rails are forming the guiding members for both the first and second longitudinal section of the boom. For example, one part of the one or more rails may form the guiding means for the first longitudinal section of the boom and a second part of the one or more rails may form the guiding means for the second longitudinal section of the boom.

[0044] Optionally, the crane may have an extendable boom comprising a base boom section and at least one telescopic boom section, preferably wherein the at least one telescopic section is telescopically adjustable with respect to the base boom section such that a height of the crane is adjustable, and wherein the first longitudinal section of the boom corresponds to the base boom section and the second longitudinal section of the boom corresponds to the at least one telescopic section.

[0045] According to a second aspect of the present disclosure, a method is provided for controlling a load during lifting of the load from an initial height up to a final height, higher than the initial height, using a crane having a boom. The method comprises: a) during a first lifting phase, during lifting of the load from the initial height to a first intermediate height:

[0046] - using the first and second winch-driven steering line for horizontally controlling the load with respect to a horizontal plane by controlling a position and / or movement of the first and second suspension member along the first longitudinal section of the boom and by controlling any of a suspension length, a tension and / or force of the first and second steering line, and, at the same time,

[0047] - using the third and fourth winch-driven steering line for vertically controlling the load with respect to a vertical plane, perpendicular to the horizontal plane, by controlling a position and / or movement of the third and fourth suspension member along the second longitudinal section of the boom and by controlling any of a suspension length, tension and / or force of the third and fourth steering line, and / or b) during a second lifting phase, during lifting of the load from a second intermediate height, equal or higher than the first intermediate height, to the final height:

[0048] - using the first and second winch-driven steering line for vertically controlling the load with respect to the vertical plane by controlling a position and / or movement of the first and second suspension member along the first longitudinal section of the boom and by controlling any of a suspension length, a tension and / or force of the first and second steering line, and, at the same time, - using the third and fourth winch-driven steering line for horizontally controlling the load with respect to the horizontal plane by controlling a position and / or movement of the third and fourth suspension member along the second longitudinal section of the boom and by controlling any of a suspension length, a tension and / or force of the third and fourth steering line.

[0049] Optionally or additionally, the method may comprise a transition phase between the first and second lifting phase. When the first intermediate height is lower than the second intermediate height, the method further comprises lifting the load from the first intermediate height to the second intermediate height, wherein at the start of the transition phase, the first and second winch-driven steering line are horizontally controlling the load and the third and fourth winch-driven steering line are vertically controlling load, and at the end of the transition phase, the third and fourth winch-driven steering line are horizontally controlling the load and the first and second winch-driven steering line are vertically controlling the load.

[0050] Short description of the drawings

[0051] Further aspects of the present disclosure will be explained in greater detail by way of example and with reference to the accompanying drawings in which:

[0052] Fig.l shows a lateral side view of an embodiment of crane comprising a boom with a fixed length and a steering line system according to the present invention, and wherein a load item is shown to be picked up and lifted up at a pick-up location, and wherein the first and second suspension member are part of respectively a first and a second trolley on one side of the crane boom and movable along a first longitudinal section of the boom, and wherein the third and fourth suspension member are part of a traverse mounted on a carriage on an opposite side of the boom and movable along a second longitudinal section of the boom, Fig.2 shows a lateral side view of the crane shown on Fig.l wherein the load item has been lifted further up while, in this example, the first and second suspension member have been moved from their start position to an end of stroke position, and the third and fourth suspension member were maintained in a fixed position, ,

[0053] Fig.3 shows a lateral side view of the crane shown on Fig.l and Fig.2 wherein the load item has been lifted further up while, in this example, the first and second suspension member have been maintained in a fixed position along the first longitudinal section of the boom and wherein the third and fourth suspension member have been maintained in a fixed position along the second longitudinal section of the boom,

[0054] Fig.4 shows a lateral side view of the crane shown on Fig.l to Fig.3 wherein the load item has been lifted further up to a maximum height position while, in this example, the first and second suspension member have been maintained in a fixed position along the first section of the boom and the third and fourth suspension member have been moved along the second section of the boom,

[0055] Fig.5 shows a top view of the boom of the crane shown on Fig.l to Fig.4, with the first and second suspension members on a first and second trolley and the third and fourth suspension members on a traverse,

[0056] Fig.6 to Fig.9 show a lateral side view of an embodiment of a crane comprising a telescopic boom and a steering line system according to the present invention, and wherein different operational stages of the crane, similar to the configurations shown on Fig.l to Fig.4, are schematically illustrated,

[0057] Fig.10 shows a top view of the telescopic boom of the crane shown on Fig.6, with the first and second suspension members on a first and second trolley and the third and fourth suspension members on a traverse,

[0058] Fig.11 to Fig.14 shows side views of crane having a boom with a fixed length, in similar configurations as in Fig.l to Fig.4, wherein the first and second suspension members are on a first and second trolley respectively and the third and fourth suspension members are on a third and fourth trolley respectively,

[0059] Fig.15 shows a top view of the boom of the crane shown on Fig.11 to Fig.14, with the first and second suspension members on respectively a first and a second trolley and the third and fourth suspension members on respectively a third and fourth trolley,

[0060] Fig.16 is an embodiment of a crane comprising a telescopic boom and a steering line system according to the present disclosure wherein the first and second suspension members are on a first and second trolley respectively and the third and fourth suspension members are on a third and fourth trolley respectively,

[0061] Fig.17 is a top view of a portion of the boom illustrating a carriage supporting a traverse beam having suspension members at a first and second end of the traverse beam,

[0062] Fig.18 is a isometric view of an embodiment of a carriage supporting a traverse beam,

[0063] Fig.19 schematically illustrates the steering line system coupled to a boom of a crane according to the present invention, wherein a first and second suspension member suspending the first and second steering lines to the boom are moveable along a first portion of the boom over a first travel stroke ATI, and wherein the third and fourth suspension members suspending the third and fourth steering lines to the boom are movable along a second portion of the boom over a second travel stroke AT2.

[0064] The drawings of the figures are neither drawn to scale nor proportioned. Generally, identical components are denoted by the same reference numerals in the figures.

[0065] Detailed description of embodiments

[0066] According to a first aspect of the invention, a steering line system for controlling a load lifted by a crane is provided. With reference to Fig.1 to Fig.4, Fig.6 to Fig.9, Fig.11 to Fig.14, and Fig.16, lateral side views of embodiments of a crane 200 comprising a steering line system for controlling a load 50 lifted by the crane according to the present invention are shown.

[0067] The crane is a boom-type of crane comprising a boom 100 elongating along a longitudinal axis L. The boom 100 may have a fixed length along the longitudinal axis, as shown for example on Fig.l to Fig.4 and on Fig.11 to Fig.14, or the boom 100 may have a variable length, e.g. a telescopic boom, as shown for example on Fig.6 to Fig.9 and Fig.16.

[0068] The crane 200 generally comprises a pedestal or base structure 120 and a slewing or rotating platform 170 supported by the pedestal or base structure.

[0069] The boom is generally pivotally coupled to the slewing or rotating platform. When the crane is in operation, the angle of the boom with respect to a horizontal plane HP, or base level defined by a base plane BP, is typically referred to as a boom angle a, which may have a value for example between 45° and 88°, preferably between 70° and 88°. For pivoting the boom and positioning the boom at a required boom angle a, a boom luffing device, known in the art, is provided comprising for example one or more luffing winches and one or more luffing cables 180.

[0070] Typically, the crane 200 further comprises a hoist assembly 60 coupled to the boom 100 for lifting a load 50 or lifting the load 50 together with a load supporting device 55 supporting the load 50. The load supporting device 55 may be a specific tool for lifting a specific load, e.g. for lifting a blade of a wind turbine or any other component of a wind turbine.

[0071] In embodiments, the hoist assembly 60 may comprise at least one or more hoist winches, one or more hoist cables 61, one or more hoist sheaves 62 near the tip of the boom, and a hoist block 63, which can be a main hoist block or an auxiliary host block.

[0072] The boom 100 may be embodied as a lattice hollow box structure having for example a rectangular cross-sectional shape, a triangular cross- sectional shape or any other suitable cross-sectional shape. The boom typically has a front and opposing rear side and two opposing lateral sides. The front side of the boom corresponds to the side where, when the crane is in operation, the hoisting is performed with the hoisting assembly 60. Hence, when the boom is in positioned at a boom angle a, the front side of the boom faces towards for instance the hoist block 63 of the hoisting assembly. Figures 5, 10 and 15 are examples illustrating a rear side of the boom 100 while Figures 1 to 4, 6 to 9 and 11 to 14 are examples illustrating a lateral side of the boom 100.

[0073] In embodiments, the crane may be an offshore crane for installing for example offshore wind turbines. The crane 200 may be mounted on a jackup vessel or any other type of suitable vessel.

[0074] In the figures referenced above illustrating examples of an embodiment of the crane 200, the crane is shown as being embodied as a so- called leg-encircling crane wherein a leg 150, e.g. a jack-up leg, extends through the pedestal or base structure 120 of the crane.

[0075] In further embodiments, the crane may be a land-based crane, used to install for example wind turbines.

[0076] The cranes 200 according to the present invention are equipped with a steering line system for controlling a load 50 lifted by the crane 200. The steering line system allows to control the load 50 both horizontally as well as vertically.

[0077] Horizontally and vertically are defined with respect to respectively a horizontal plane HP and a vertical plane VP, perpendicular to the horizontal plane. The horizontal plane is defined as a plane perpendicular to the vertical plane and wherein the vertical plane is oriented in a vertical direction defined by gravity.

[0078] In embodiments, the horizontal plane HP is parallel with a base plane BP or a base level the crane is positioned on. Horizontally controlling the load has to be construed as controlling a motion, position and / or orientation of the load in a plane parallel with the horizontal plane, which implies for instance controlling a rotation of the load 50 around an axis traverse or perpendicular to the horizontal plane. An example of a potential rotation around an axis traverse to the horizontal plane is a rotation around the hoist cable 61 of the hoisting assembly 60. Vertically controlling the load has to be construed as controlling a motion, position and / or orientation of the load in a plane parallel with the vertical plane, which implies for instance controlling a rotation of the load 50 around an axis parallel with the horizontal plane.

[0079] As schematically illustrated on Fig.19, the steering line system according to the present invention comprises at least a first 11, second 12, third 13 and fourth 14 winch-driven steering line suspendable between the boom 100 and the load 50 or between the boom 100 and the load supporting device 55 supporting the load.

[0080] In embodiments, the steering line system may comprise more than four steering lines.

[0081] The winch-driven steering lines have to be construed as ropeshaving a length that is extendable by using a winch. The ropes may for example be wire ropes, i.e. steel cables, or alternatively the ropes may be fibre ropes. Each steering line suspended between the boom and the load may be a single cable or may be a double cable, a so-called double fall .

[0082] The steering line system further comprises a first suspension member 21 and a second suspension member 22 for coupling respectively the first 11 and second 12 winch-driven steering line to the boom 100, and a third suspension member 23 and a fourth suspension member 24 for coupling respectively the third 13 and fourth 14 steering line to the boom 100.

[0083] A suspension member may comprise any of or a combination of: one or more pulleys, one or more sheaves, one or more cable-guiding elements, one or more hooks or any other element suitable for coupling a winch-driven steering line to the boom. In embodiments, the suspension member may be a single pulley or a single sheave.

[0084] Typically, the sheave or pulley forming the suspension member are arranged for rotating around an axis.

[0085] The suspension members 21,22,23,24 are not fixed to the boom but are moveably coupled to the boom such that a position of the suspension members along the boom 100 may be varied. Indeed, the steering line system comprises first moving means configured for moving the first 21 and second 22 suspension member along a first longitudinal section Bl of the boom 100 such that a height of the first and second suspension member with respect to a base level or base plane BP of the crane is adjustable by moving the first and second suspension members along the first longitudinal section of the boom. For example, as illustrated on Fig.19, the first 21 and second 22 suspension member may be moved along a first travel stroke ATI from a start position at a height Hl to an end of travel stroke at a height H2, wherein the height may be measured with respect to the horizontal plane HP, which may correspond to a base plane BP or base level, or any other suitable reference plane.

[0086] The steering line system further comprises second moving means configured for moving the third 23 and fourth 24 suspension member along a second longitudinal section B2 of the boom 100, different from the first longitudinal section, preferably adjacent to the first longitudinal section, such that a height of the third and fourth suspension member with respect to the horizontal level HL or base plane BP of the crane is adjustable by moving the third 23 and fourth 24 suspension members along the second longitudinal section B2 of the boom. For example, as illustrated on Fig.19, the third 23 and fourth 24 suspension member may be moved along a second travel stroke AT2 from a start position at a height H3 to an end of travel stroke at a height H4.

[0087] The first Bl and the second B2 longitudinal section of the boom may be considered as respectively a lower part and an upper part of the boom 100. The upper section of the boom allows for elevating loads to higher heights when compared to heights reachable with the lower section.

[0088] In the embodiments shown on Figures 1 to 16, the heights of the start and the end of travel positions of the suspension members are such that Hl < H2 < H3 < H4. Hence, in these embodiments, there is no overlap between the first ATI and second AT2 travel strokes. In other embodiments an overlap between the first and second travel stroke may be possible such that there may be an overlap in height positions the first / second 21,22 suspension members and the height positions the third / fourth 23,24 suspension members may reach.

[0089] In embodiments, the first moving means comprises one or more trolleys or one or more carriages for moving the first 21 and second 22 suspension member along the first longitudinal section Bl of the boom 100. Similarly, the second moving means comprises one or more trolleys or one or more carriages for moving the third 23 and fourth 24 suspension member along the second longitudinal section B2 of the boom 100. Hence, the suspension members 21,22,23,24 may be provided on either a trolley or on a carriage.

[0090] For example, for the cranes shown on Fig.l to Fig.10, the first moving means comprise a first trolley 30a for moving the first suspension member 21 and a second trolley 30b for moving the second suspension member 22. As schematically illustrated on Fig.5, each of the first 30a and second 30b trolley may be configured for engaging with respectively a first 102a and a second 102b guiding member for guiding the trolley along the boom.

[0091] In embodiments, the first and second guiding member may for example be respectively a first and second rail attached to the first longitudinal section Bl of the boom. A first and second rail may be attached to for example a first 101a and second 101b chord of the boom 100, or alternatively, the chords may be configured for forming a guiding member for the trolleys. In embodiments, the boom may comprise one or more rails extending at least along the first and second section of the boom such that the same one or more rails are forming the guiding members for both the first and second longitudinal section of the boom. For example, one part of the one or more rails may form the guiding means for the first longitudinal section of the boom and a second part of the one or more rails may form the guiding means for the second longitudinal section of the boom.

[0092] In further embodiments, each of the first and second guiding member may be embodied as a skid / sliding surface.

[0093] In embodiments wherein the first moving means comprise a first 30a and a second trolley 30b, as shown for example on Fig.5, Fig.10 and Fig.15, each of the trolleys may comprise any of a pulley, a sheave or any other suitable element for forming respectively the first 21 and second 22 suspension member. The suspension member, for instance embodied as a pulley or a sheave may be attached to a frame or body of the trolley.

[0094] In embodiments, each of the trolleys 30a, 30b may comprise one or more rollers configured for engaging with respectively a first and second rail located on the first longitudinal section of the boom.

[0095] In embodiments, the suspension member, e.g. a sheave or a pulley, may be pivotably attached to the trolley. For example, the sheave or pulley may pivot around a pivot axis that is parallel with the rail the trolley is engaging with.

[0096] For embodiments wherein the first moving means comprise for instance a first and second trolley, the moving means may comprise driving means for driving the movement of the trolleys.

[0097] In embodiments, the driving means for driving the trolleys may comprise one or more drive winches, for example a first and second drive winch for respectively driving the first 30a and second 30b trolley. The drive winches may either be mounted on the boom or the rotating platform 17, or alternatively the drive winches may be mounted on the trolleys. In other embodiments, an electromotor or a hydraulic motor may be used to drive the trolleys. For instance, in combination with a rack and pinion system wherein the motor may drive a pinion engaging with a rack coupled to the rail. In further embodiments, a skidding system may be used wherein holes provided on the rails may be used in combination with a hydraulically driven pin.

[0098] As further illustrated on Fig.l to Fig.10 the second moving means may comprise a carriage 40 for moving the third and fourth suspension member along the second longitudinal section B2 the boom. In these embodiments, the carriage is supporting a traverse member 45 or a traverse beam 45 and wherein a first 46 end and a second end 47 of the traverse beam is forming the third and fourth suspension member.

[0099] With reference to Fig.17, a top view of a portion of the boom 100 is shown to illustrate a carriage 40 that is forming the second moving means for moving along the second longitudinal section B2 of the boom and wherein the carriage is supporting a traverse member 45 or traverse beam 45 having respectively the third 23 and fourth 24 suspension members at a first 46 and second 47 end of the traverse member or traverse beam 45. As illustrated on Fig.17, the traverse member or traverse beam 45 has a length TL transverse, preferably perpendicular to the longitudinal axis L of the boom, that is longer than the lateral width B-LW of the boom measured between the two lateral sides of the boom. In other words, the first 46 and second 47 end of the traverse member or traverse beam extend beyond the lateral boundaries of the boom. In this way, the third 13 and fourth 14 steering line may be well separated from each other for coupling to for example an elongated load, such as a blade of a wind turbine.

[0100] Fig.18 is an isometric view of an embodiment of a carriage 40 forming the second moving means and wherein the carriage is supporting a traverse member or beam 45 having ends 46 and 47 that are forming respectively the third 23 and fourth 24 suspension member. In this embodiment, as shown on Fig.18, the third 23 and fourth 24 suspension member are embodied as a pulley 23, 24. The carriage 40 may further comprise one or more sets of rollers 48 configured for engaging with corresponding rails 49a, 49b. In Fig.18, a first 49a and second 49b rail are shown spaced from each other. The rails may for example be welded to chords of the boom. In embodiments, both a vertical and a horizontal set of rollers may engage with one or both of the rails.

[0101] For driving the second moving means, for instance for driving the carriage 40 supporting the traverse member 45 or traverse beam 45, driving means are provided. The driving means for driving the carriage may comprise one or more drive winches which may either be mounted on the boom or the rotating platform 17, or alternatively the drive winches may be mounted on the carriage. In Fig.18, two pulleys 43 are shown which are forming part of winch-driven drive means for driving the movement of the carriage. In other embodiments, the carriage 40 may be driven by a motor, for instance in combination with a rack and pinion system

[0102] In embodiments, as illustrated for example on Fig.11 to Fig.16, the first moving means comprise a first 30a and second 30b trolley for moving respectively the first 21 and second 22 suspension members along the first longitudinal section Bl of the boom, and the second moving means comprise a third 30c and fourth 30d trolley for moving respectively the third 23 and fourth 24 suspension members along the second longitudinal section B2 of the boom 100.

[0103] Advantageously, by providing two independently moving trolleys moving along the second longitudinal section B2 of the boom, an elongated load, such as a blade of a wind turbine may also be held in a vertical position rather than in a horizontal position, wherein for example the third trolley may maintain the top of the blade stable and the fourth trolley may maintain the lower part of the blade stable.

[0104] A further advantage of having the third and fourth trolley moving independently from each other is that a diagonal installation of a blade, for example at 30°, is also possible. In this case, one trolley is located higher than the other to maintain horizontal orientation of the steering lines. This also depends on the location of the attachment points on the lifting tool, which itself is also oriented diagonally in that case. Stabbing of the blade may be performed for example at 30° above or at 30° below the horizontal.

[0105] In further embodiments the first moving means for moving the first 21 and second 22 suspension member along the first longitudinal section of the boom may comprise a further carriage supporting a traverse member or traverse beam having ends forming the suspension members. The ends of the traverse member may be embodied as pulleys or sheaves.

[0106] In embodiments, each of the first and second longitudinal section of the boom may be provided with a carriage supporting a traverse member or traverse beam. In other embodiments one of the two longitudinal sections may be provided with a carriage supporting the traverse member or traverse beam and another longitudinal section may be provided with two trolleys.

[0107] The first and second moving means, e.g. trolleys and / or carriages may be mounted on for example the front or rear sides of the boom. For example, in Fig.l to Fig.10, the first 30a and second 30b trolley are mounted on the front side of the boom and the carriage 40 supporting the traverse member or traverse beam 45 is mounted on the rear side of the boom. In other embodiments, the carriage 40 supporting the traverse member 45 may be mounted on the front side of the boom.

[0108] In further embodiments, the first and / or second moving means, e.g. trolleys and / or carriages may be mounted on the lateral sides of the boom. In these embodiments, guiding rails may be attached to the lateral sides for guiding the trolleys or carriages.

[0109] In embodiments the steering line system comprises a first, second, third and fourth steering line winch associated to respectively the first 11, second 12, third 13 and fourth 14 winch-driven steering line. In these embodiments, each winch is configured for controlling a suspension length SL1, SL2, SL3, SL4 between the boom and the load and / or for controlling a tension strength in the steering line. The suspension lengths SL1, SL2, SL3, SL4 of the first 11, second 12 , third 13 and fourth 14 steering hne between the suspension members 21,22,23,24 and the load 50 is schematically illustrated on Fig.19.

[0110] In embodiments, the steering line winches may be attached to any of: a lower part of the boom, an upper part of the boom, the slewing or rotating platform 170 of the crane, or a crane cabin.

[0111] In embodiments, the first and second steering line winch may be attached to the first moving means and / or the third and fourth steering line winches may be attached to the second moving means. For example the first and second steering line winch may be attached to respectively the first and second trolley and / or the third and fourth steering hne winch may be attached to the carriage supporting the traverse.

[0112] In other embodiments, the one or more of the steering lines winches may be attached to the load 50 or to the load supporting device 55.

[0113] In embodiments, the first and second moving means are configured such that the motion of the first 21 and second 22 suspension member along the first section B 1 of the boom is independent from the motion of the third 23 and fourth 24 suspension member along the second section B2 of the boom. In other words, the control of the height of the suspension members of the first longitudinal section of the boom is independent from the control of the height of the suspension members of the second longitudinal section. In this way, as further discussed below in more detail, the pair of steering lines in the first and second longitudinal section of the boom may functionally be used in a different way, for instance the first 11 and second 12 steering line may be used for horizontal control of the load and the third 13 and fourth 14 steering line may be used for vertical control of the load, or vice versa.

[0114] In embodiments, the motion of the first suspension member 21 is independent of the motion of the second suspension member 22 and / or wherein the motion of the third suspension member 23 is independent of the motion of the fourth suspension member 24. This can for example be realized, as discussed above, by using a first and a second trolley for moving respectively the first and second suspension member and / or using a third and fourth trolley for moving respectively the third and fourth suspension member.

[0115] With the steering line system according to the present invention, the motion of any of the suspension members 21,22,23,24 is independent of the motion of the load lifted by a hoist assembly of the crane. Indeed, as discussed above, each of the first and second moving means may have its proper driving means for driving the motion of the suspension members along the boom, independently from the hoisting of the load.

[0116] In embodiments, the steering line system may comprise a controller configured for controlling a movement and / or position of the first and second suspension member along the first longitudinal section of the boom, and for controlling a movement and / or position of the third and fourth suspension member along the second longitudinal section of the boom.

[0117] The controller may further be configured for controlling for each of the steering line winches, a suspension length SL1, SL2, SL3, SL4 between the boom and the load and / or controlling a tension strength in the steering line.

[0118] In embodiments, the controller for controlling the steering line system may be part of a control system of the crane. In this way, a single person may control both the crane and the steering line system, e.g. from the crane cabin.

[0119] For embodiments comprising more than four winch-driven steering lines, e.g. a fifth and a sixth steering line, corresponding suspension members are provided, e.g. a fifth and sixth suspension member may be provided. In embodiments, the second moving means may be configured for moving additional suspension members, for example for moving an additional fifth and sixth suspension member along the second longitudinal section of the boom. Optionally or additionally, the first moving means may also be configured for moving further suspension members, in addition to the first and second suspension members, along the first longitudinal section of the boom. In this way, additional steering lines may be used.

[0120] According to a second aspect of the present disclosure, a method for controlling a load 50 during lifting of the load from an initial height HL-I up to a final height HL-F using a crane as described above is disclosed.

[0121] With reference to Fig.1 to Fig.4, Fig.6 to Fig.9, and Fig.11 to Fig.14, the position of the first, second, third and fourth suspension member and the orientation of the corresponding steering lines for different heights reached during lifting of the load from an initial height HL-I to a final height HL-F when applying the method according to the present invention is shown. For example, in Fig.l, Fig.6 and Fig.11, the load is at an initial height HL-I and in Fig.4, Fig.9 and Fig.14, a final height HL-F for the load, higher than the initial height HL-I is reached. In Fig.2, Fig.7 and Fig.12, the load is shown to be at a first intermediate height HL-M1, between the initial height HL-I and the final height HL-F, and in Fig.3, Fig.8 and Fig.13, the load is shown to be at a second intermediate height HL-M2.

[0122] The heights of the load, e.g. the heights HL-I, HL-F, HL-M1 and HL-M2 may be defined with respect to a horizontal plane HP, which is a reference plane for defining the heights.

[0123] As mentioned above, the horizontal plane HP is a plane perpendicular to the vertical plane and wherein the vertical plane is oriented in a vertical direction defined by gravity. In embodiments, the base level or base plane BP the crane is positioned on is parallel with the horizontal plane HP.

[0124] The method for controlling the load 50 during lifting of the load from an initial height HL-I up to a final height HL-F comprises at least a first and a second lifting phase. During a first lifting phase, the method comprises lifting the load from the initial height HL-I to a first intermediate height HL- M1 while using the first 11 and second 12 winch-driven steering line for horizontally controlling the load 50 and using the third 13 and fourth 14 winch-driven steering line for vertically controlling the load. The horizontal control is with respect to the horizontal plane HP and the vertical control is with respect to the vertical plane VP.

[0125] In embodiments, horizontally controlling the load comprises controlling a motion, position and / or orientation of the load 50 in a plane parallel with the horizontal plane HP, and wherein vertically controlling the load comprises controlling a motion, position and / or orientation of the load 50 in a plane parallel with the vertical plane VP.

[0126] Horizontally controlling the load comprises for instance controlling a rotation of the load 50 around an axis traverse or perpendicular to the horizontal plane HP, for example a rotation around the hoist cable 61 of the hoisting assembly 60.

[0127] Vertically controlling the load comprises for instance controlling a rotation of the load 50 around an axis parallel with the horizontal plane HP.

[0128] Horizontally controlling the load during the first lifting phase comprises controlling a position and / or movement of the first and second suspension member along the first longitudinal section Bl of the boom 100, and by controlling any of a suspension length SL1, SL2, tension and / or force of the first 11 and second 12 winch-driven steering line during lifting of the load from the initial height HL-I to the first intermediate height HL-M1.

[0129] In embodiments, controlling the suspension length of the first 11 and 12 second winch-driven steering line during lifting of the load from the initial height to the first intermediate height during the first lifting phase comprises reducing a suspension length SL1, SL2 of the first 11 and second 12 winch-driven steering line during lifting from the initial height to the first intermediate height. This is for example schematically illustrated on Fig.2 where the load 50 has reached the first intermediate height HL-M1 and wherein the suspension length of the first 11 and second 12 winch-driven steering line is reduced compared to the suspension length when the load was at the initial height HL-I, as shown on Fig.l.

[0130] Vertically controlling the load during the first lifting phase, performed at the same time as the horizontal control, comprises controlling a position and / or movement of the third 13 and fourth 14 suspension member in a fixed position along the second longitudinal section B2 of the boom 100 and controlling any of a suspension length, tension and / or force of the third

[0131] 12 and fourth 13 winch-driven steering line. In embodiments, the fixed position along the second longitudinal section B2 of the boom corresponds to a start position for starting a travel stroke AT2 for the third and fourth suspension member. In embodiments, during the first lifting phase, the third

[0132] 13 and fourth 14 suspension member may be maintained in a fixed position along the second longitudinal section B2 of the boom 100. In other embodiments, the third and fourth suspension member may also be moved during the first lifting phase.

[0133] Generally, the suspension length of the third 12 and fourth 13 winch-driven steering line is controlled during the first lifting phase such that during lifting of the load 50 from the initial height HL-I to the first intermediate height HL-M1, the suspension length of the third 13 and fourth

[0134] 14 winch-driven steering line is being reduced.

[0135] During a second lifting phase, the method comprises lifting the load 50 from a second intermediate height HL-M2, equal or higher than the first intermediate height HL-M1, to the final height HL-F while using the first 11 and second 12 winch-driven steering line for vertically controlling the load 50 with respect to the vertical plane VP, and while using the third 13 and fourth 14 winch-driven steering line for horizontally controlling the load 50 with respect to the horizontal plane.

[0136] Generally, HL-I < HL-M1 < HL-M2 < HL-F.

[0137] Vertically controlling the load during the second lifting phase comprises controlling a position and / or movement of the first and second suspension member along the first longitudinal section of the boom and controlling any of a suspension length, a tension and / or force of the first 11 and second 12 winch-driven steering line. Generally, during lifting of the load from the second intermediate height HL-IM2 to the final height HL-F, the suspension length SL1, SL2 of the first 11 and second 12 winch-driven steering line is being increased.

[0138] In embodiments, during the second lifting phase, the first and second suspension member may be at a fixed position along the first longitudinal section Bl of the boom. This fixed position may for example corresponds to an end of travel position for the first and second suspension member, i.e. the position after the first and second suspension member have travelled the travel stroke ATI along the first longitudinal section Bl of the boom. In embodiments, during the second lifting phase, the first and second suspension member may be positioned at any position along the first section of the boom.

[0139] Horizontally controlling the load 50 during the second lifting phase, that is performed at the same time as the vertical control, involves controlling a position of the third and fourth suspension member along the second longitudinal section B2 of the boom and controlling a suspension length SL3, SL4 of the third 13 and fourth 14 winch-driven steering line.

[0140] In embodiments, controlling the suspension length SL3, SL4 of the third 13 and fourth 14 winch-driven steering line during lifting of the load 50 from the second intermediate height HL-M2 to the final height HL-F during the second lifting phase may comprise reducing a suspension length of the third and fourth winch-driven steering line during lifting from the second intermediate height to the final height. This is for example schematically illustrated on Fig.4 where the load has reached the final height HL-F and wherein the suspension length of the third 13 and fourth 14 winch-driven steering line is reduced compared to the suspension length when the load was at the second intermediate height HL-M2, as shown on Fig.3.

[0141] In embodiments wherein the first intermediate height HL-M1 is lower than the second intermediate height HL-M2, the method further comprises lifting the load from the first intermediate height to the second intermediate height during a transition phase between the first and second lifting phase. At the start of the transition phase, the first and second winch- driven steering line are horizontally controlhng the load and the third and fourth winch-driven steering line are vertically controlling load, and at the end of the transition phase, the third and fourth winch-driven steering hne are horizontally controlling the load and the first and second winch-driven steering line are vertically controlling the load.

[0142] In other words, during the transition phase, there is a transition of the horizontal and vertical control between the steering lines associated to the first longitudinal section of the boom and the steering lines associated to the second longitudinal section of the boom.

[0143] During the transition phase, the method comprises controlling any of a suspension length, tension and / or force of the first, second, third and fourth winch- driven steering line.

[0144] In some embodiments, during the transition phase, the method may comprise steps of:

[0145] -maintaining the first and second suspension member in a fixed position along the first longitudinal section of the boom,

[0146] -maintaining the third and fourth suspension member in a fixed position along the second longitudinal section of the boom, As mentioned above, the fixed position of the first and second suspension member along the first longitudinal section of the boom may correspond to a position of the first and second suspension member at the end of the first lifting phase, and the fixed position for the third and fourth suspension member may correspond to a start position for the third and fourth suspension member for starting a travel stroke AT2 along the second longitudinal section of the boom.

[0147] In other embodiments, during the transition phase, the suspension members are not necessarily in a static position, and the method may comprise moving the first and second suspension members along the first longitudinal section of the boom and / or moving the third and fourth suspension members along the second longitudinal section of the boom. In embodiments, during the transition phase, controlling the suspension length of the first 11, second 12, third 13 and fourth 14 winch- driven steering line is performed such that during lifting of the load from the first HL-M1 to the second HL-M2 intermediate height, the suspension length SL1, SL2 of the first 11 and second 12 winch-driven steering line is being increased and the suspension length SL3, SL4 of the third 13 and fourth 14 winch-driven steering line is being reduced. The positions of the steering lines at the start and end of the transition phase are for example shown on Fig.2 and Fig.3 respectively, on Fig.7 and Fig.8 respectively, and on Fig.12 and Fig.13 respectively.

[0148] In embodiments, during any of the first lifting phase, second lifting phase or transition phase, a suspension strength for each of the first, second, third and fourth winch-driven steering line is controlled.

[0149] In embodiments, during the first lifting phase the first winch- driven steering line and the second winch-driven steering line are oriented with respect to the horizontal plane at an angle smaller than 45°, preferably smaller than 35°, more preferably smaller than 25°, and / or during the second lifting phase the third winch-driven steering line and the fourth winch-driven steering line are oriented with respect to the horizontal plane at an angle smaller than 45°, preferably smaller than 35°, more preferably smaller than 25°.

[0150] In embodiments, during the first lifting phase the third winch- driven steering line and the fourth winch-driven steering line are oriented with respect to the vertical plane at an angle smaller than 45°, preferably smaller than 35°, more preferably smaller than 25°, and / or during the second lifting phase the first winch-driven steering line and the second winch-driven steering line are oriented with respect to the vertical plane at an angle smaller than 45°, preferably smaller than 35°, more preferably smaller than 25°.

[0151] The present disclosure has been described in terms of specific embodiments, which are illustrative of the disclosure and not to be construed as limiting. It will be appreciated by persons skilled in the art that the present disclosure is not limited by what has been particularly shown and / or described and that alternatives or modified embodiments could be developed in the light of the overall teaching of this disclosure. The drawings described are only schematic and are non-limiting.

[0152] Use of the verb "to comprise", as well as the respective conjugations, does not exclude the presence of elements other than those stated. Use of the article "a", "an" or "the" preceding an element does not exclude the presence of a plurality of such elements.

[0153] Furthermore, the terms first, second and the like in the description and in the claims, are used for distinguishing between similar elements and not necessarily for describing a sequence, either temporally, spatially, in ranking or in any other manner. It is to be understood that the terms so used are interchangeable under appropriate circumstances and that the embodiments of the disclosure described herein are capable of operation in other sequences than described or illustrated herein.

[0154] Reference throughout this specification to “one embodiment” or “an embodiment” means that a particular feature, structure or characteristic described in connection with the embodiments is included in one or more embodiment of the present disclosure. Thus, appearances of the phrases “in one embodiment” or “in an embodiment” in various places throughout this specification are not necessarily all referring to the same embodiment, but may. Furthermore, the particular features, structures or characteristics may be combined in any suitable manner, as would be apparent to one ordinary skill in the art from this disclosure, in one or more embodiments. Reference numbers

Claims

Claims1. A steering line system for controlling a load lifted by a crane having a boom elongating along a longitudinal axis, the steering line system comprising:• at least a first, second, third and fourth winch-driven steering line suspendable between the boom and the load or between the boom and a load supporting device supporting the load,• a first suspension member and a second suspension member for coupling respectively said first and second winch- driven steering line to the boom,• first moving means configured for moving said first and second suspension member along a first longitudinal section of the boom such that a height of the first and second suspension member with respect to a base level of the crane is adjustable by moving the first and second suspension members along the first longitudinal section of the boom,• a third suspension member and a fourth suspension member for coupling respectively the third and fourth steering line to the boom,• second moving means configured for moving said third and fourth suspension member along a second longitudinal section of the boom, different from the first longitudinal section, preferably adjacent to the first longitudinal section, such that a height of the third and fourth suspension member with respect to the base level of the crane is adjustable by moving the third and fourth suspension members along the second longitudinal section of the boom.

2. The steering line system according to claim 1 wherein each of the suspension members comprises any of or a combination of: one or morepulleys, one or more sheaves, one or more cable-guiding elements, one or more hooks or any other element suitable for coupling a winch-driven steering line to the boom.

3. The steering line system according to any of previous claims comprising a controller configured for:-controlling a movement and / or position of the first and second suspension member along the first longitudinal section of the boom, and-controlling a movement and / or position of the third and fourth suspension member along the second longitudinal section of the boom.

4. The steering line system according to claim 3 wherein the controller is further configured for controlling any of a suspension length, a tension and / or a force of said at least first, second, third and fourth winch- driven steering lines.

5. The steering line system according to any of previous claims comprising a first, second, third and fourth steering line winch associated to respectively said first, second, third and fourth winch-driven steering line, and wherein each winch is configured for controlling a suspension length between the boom and the load and / or for controlling a tension strength in the steering line, preferably wherein when depending on claim 3 or claim 4, said controller is further configured for controlling said first, second, third and fourth steering line winch.

6. The steering line system according to any of previous claims wherein said first moving means comprises one or more trolleys or one or more carriages for moving said first and second suspension member along the first longitudinal section of the boom.

7. The steering line system according to any of previous claims wherein said first moving means comprise a first trolley for moving the first suspension member and a second trolley for moving the second suspension member.

8. The steering line system according to claim 7 wherein each of said first and second trolley comprises any of a pulley, a sheave or any other suitable element for forming respectively said first and second suspension member.

9. The steering line system according to any of previous claims wherein said second moving means comprises a carriage or one or more trolleys for moving said third and fourth suspension member along the second longitudinal section of the boom.

10. The steering line system according to any of previous claims wherein said second moving means comprise a carriage supporting a traverse member, or a traverse beam, and wherein a first end and a second end of said traverse member or traverse beam is forming said third and fourth suspension member, preferably wherein the first and second end are provided with a pulley or a sheave.

11. The steering line system according to any of previous claims wherein the motion of said first and second suspension member along the first section of the boom is independent from the motion of the third and fourth suspension member along the second section of the boom.

12. The steering line system according to any of previous claims wherein the motion of the first suspension member is independent of the motion of the second suspension member and / or wherein the motion of the third suspension member is independent of the motion of the fourth suspension member.

13. The steering line system according to any of previous claims wherein the motion of any of the suspension members is independent of the motion of the load lifted by a hoist assembly of the crane.

14. The steering line system according to any of previous claims further comprising a fifth and sixth winch-driven steering line suspendable between the boom and the load or between the boom and the load supporting device supporting the load.

15. The steering lines system according to claim 14 comprising a fifth and sixth suspension member for coupling respectively said fifth and sixth winch-driven steering line to the boom.

16. The steering line system according to claim 15 wherein the second moving means are configured for moving said fifth and sixth suspension member along the second longitudinal section of the boom such that a height of the fifth and sixth suspension member with respect to a base level or base plane of the crane is adjustable by moving the fifth and sixth suspension members along the second longitudinal section of the boom.

17. A crane comprising a boom elongating along a longitudinal axis, a hoist assembly coupled to the boom for lifting a load, and a steering line system according to any of previous claims, preferably wherein the crane is a platform crane and / or an offshore crane, preferably wherein the boom is pivotable around a boom pivot axis perpendicular to the longitudinal axis of the boom.

18. The crane according to claim 17 wherein the boom comprises a first longitudinal section and a second longitudinal section, and wherein the first longitudinal section is provided with one or more guiding members for guiding the first moving means along the first longitudinal section of the boom, and wherein the second longitudinal section is provided with one or more further guiding members for guiding the second moving means.

19. The crane according to claim 18 wherein the one or more guiding members for the guiding the first moving means comprise one or more rails, and wherein the one or more further guiding members for guiding the second moving means comprise one or more further rails.

20. The crane according to claim 18 comprising one or more rails extending longitudinally along at least the first and second longitudinal section of the boom, and wherein a first part of said one or more rails is forming the one or more guiding members for guiding the first moving means and a second part of said one or more rails is forming the one or more further guiding members for guiding the second moving means.

21. The crane according to any of claims 17 to 19 wherein the first longitudinal section of the boom comprises two rails spaced from each other and configured for guiding respectively the first and second trolley, and wherein the second section of the boom comprises one or more further rails configured for guiding the carriage supporting the traverse member or traverse beam.

22. The crane according to claim 21 wherein the two spaced rails guiding the first and second trolley are coupled to two spaced chords of the boom.

23. The crane according to any of claims 17 to 22 wherein the boom is an extendable boom comprising a base boom section and at least one telescopic boom section, preferably wherein the at least one telescopic section is telescopically adjustable with respect to the base boom section such that a height of the crane is adjustable, and wherein the first longitudinal section of the boom corresponds to the base boom section and the second longitudinal section of the boom corresponds to said at least one telescopic section.

24. The steering line system according to any of claims 1 to 16 or the crane according to any of claims 17 to 22 wherein the first longitudinal section of the boom corresponds to a lower section of the boom and the second longitudinal section of the boom corresponds to the an upper section of the boom, wherein the upper section of the boom allows for elevating loads to higher heights when compared to heights reachable with the lower section.

25. A method for controlling a load during lifting of the load from an initial height up to a final height, higher than the initial height, using a crane according to any of claims 17 to 24, comprising: a) during a first lifting phase, during lifting of the load from the initial height to a first intermediate height:- using the first and second winch-driven steering line for horizontally controlling the load with respect to a horizontal plane by controlling a position and / or movement of the first and second suspension member along the first longitudinal section of the boomand by controlling any of a suspension length, a tension and / or force of the first and second steering line, and, at the same time,- using the third and fourth winch-driven steering line for vertically controlling the load with respect to a vertical plane, perpendicular to the horizontal plane, by controlling a position and / or movement of the third and fourth suspension member along the second longitudinal section of the boom and by controlling any of a suspension length, tension and / or force of the third and fourth steering line, and / or b) during a second lifting phase, during lifting of the load from a second intermediate height, equal or higher than the first intermediate height, to the final height:- using the first and second winch-driven steering line for vertically controlling the load with respect to the vertical plane by controlling a position and / or movement of the first and second suspension member along the first longitudinal section of the boom and by controlling any of a suspension length, a tension and / or force of the first and second steering line, and, at the same time,- using the third and fourth winch-driven steering line for horizontally controlling the load with respect to the horizontal plane by controlling a position and / or movement of the third and fourth suspension member along the second longitudinal section of the boom and by controlling any of a suspension length, a tension and / or force of the third and fourth steering line.

26. The method of claim 25 wherein during the first lifting phase, the third and fourth suspension member are maintained in a fixed position along the second longitudinal section of the boom and / or wherein during the second lifting phase, the first and second suspension member are maintained in a fixed position along the first longitudinal section of the boom.

27. The method of claim 26 wherein said fixed position along the second longitudinal section of the boom corresponds to a start position for starting atravel stroke for the third and fourth suspension member, and / or wherein the fixed position along the first longitudinal section of the boom corresponds to an end of travel stroke of the first and second suspension member.

28. The method according to any of claims 25 to 27 wherein the first intermediate height is lower than the second intermediate height and wherein the method further comprises lifting the load from the first intermediate height to the second intermediate height during a transition phase between the first and second lifting phase, wherein at the start of the transition phase, the first and second winch-driven steering line are horizontally controlling the load and the third and fourth winch- driven steering line are vertically controlling load, and at the end of the transition phase, the third and fourth winch-driven steering line are horizontally controlling the load and the first and second winch-driven steering line are vertically controlling the load.

29. The method of claim 28 wherein during the transition phase, the method comprises: controlling any of a suspension length, tension and / or force of the first, second, third and fourth winch-driven steering line.

30. The method of claim 28 or 29 comprising: during lifting of the load from the first to the second intermediate height, increasing the suspension length of the first and second winch-driven steering line and reducing the suspension length of the third and fourth winch-driven steering line.

31. The method of any of claims 28 to 30 wherein during the transition phase the method comprises:-maintaining the first and second suspension member in a fixed position along the first longitudinal section of the boom, preferably wherein the fixed position of the first and second suspension member corresponds to a position of the first and second suspension member at the end of the first lifting phase,- maintaining the third and fourth suspension member in a fixed position along the second longitudinal section of the boom, preferably wherein the fixed position of the third and fourthsuspension member corresponds to a start position for the third and fourth suspension member for starting the second lifting phase.

32. The method according to any of claims 25 to 31, wherein said controlling the suspension length of the third and fourth winch-driven steering line during the first lifting phase comprises reducing the suspension length of the third and fourth steering line during lifting of the load from the initial height to the first intermediate height, and wherein said controlling the suspension length of the first and second winch-driven steering line during the second lifting phase comprises increasing the suspension length of the first and second winch-driven steering line during lifting of the load from the second intermediate height to the final height.

33. The method according to any of claims 25 to 31, wherein said controlling the suspension length of the first and second winch-driven steering line during the first lifting phase comprises reducing the suspension length of the first and second winch-driven steering line during lifting of the load from the initial height to the first intermediate height, and wherein said controlling the suspension length of the third and fourth winch- driven steering line said during the second lifting phase comprises reducing a suspension length of the third and fourth winch-driven steering line during lifting of the load from the second intermediate height to the final height.

34. The method according to any of claims 25 to 33 wherein during the first lifting phase the first and second winch-driven steering line are oriented with respect to the horizontal plane at an angle smaller than 45°, preferably smaller than 35°, more preferably smaller than 25°, and during the second lifting phase the third and fourth winch-driven steering line are oriented with respect to the horizontal plane at an angle smaller than 40°, preferably smaller than 30°, more preferably smaller than 20°, and / or wherein during the first lifting phase the third winch-driven steering line and the fourth winch-driven steering line are oriented with respect to the vertical plane at an angle smaller than 45°, preferably smaller than 35°, more preferably smaller than 25°, and during the second lifting phase the firstwinch-driven steering line and the second winch-driven steering line are oriented with respect to the vertical plane at an angle smaller than 45°, preferably smaller than 35°, more preferably smaller than 25°.

35. The method according to any of claims 25 to 34 wherein said vertical plane is oriented in a vertical direction defined by gravity.

36. The method according to any of claims 25 to 35 wherein a base level or base plane the crane is positioned on is parallel with the horizontal plane.

37. The method according to any of claims 25 to 36 wherein horizontally controlling the load comprises controlling a motion, position and / or orientation of the load in a plane parallel with the horizontal plane, and wherein vertically controlling the load comprises controlling a motion, position and / or orientation of the load in a plane parallel with the vertical plane.

38. The method according to any of claims 25 to 37 wherein horizontally controlling the load comprises controlling a rotation of the load around an axis traverse or perpendicular to the horizontal plane, and wherein vertically controlling the load comprises controlling a rotation of the load around an axis parallel with the horizontal plane.

Images