EP4087809A1

EP4087809A1 - A mobile heavy lift crane system

Info

Publication number: EP4087809A1
Application number: EP20830217.4A
Authority: EP
Inventors: David ROODENBURG; Adrianus VAN DER LINDE
Original assignee: Itrec BV
Current assignee: Huisman Equipment BV
Priority date: 2020-01-06
Filing date: 2020-12-18
Publication date: 2022-11-16
Also published as: WO2021140011A1; CN114929612A; NL2024610B1

Abstract

A mobile heavy lift crane system comprising a crane (1) and a track arrangement configured to be installed on the ground and comprising: - a circular slew track assembly (100) extending over at least a slew arc about a slew center, comprising at least a pair of concentric first and second slew tracks, - a rectilinear crane track assembly (120).

Description

A MOBILE HEAVY LIFT CRANE SYSTEM

The present invention relates to the field of mobile heavy lift crane systems.

In the art of heavy lifting mobile crane systems are known, e.g. as disclosed in W02010/121134, WO2019/050405. An example of a heavy lifting mobile crane system is the SK10,000 crane system that has been developed by the company ALE.

Generally, a mobile heavy lift crane system is composed of a crane comprising:

- a crane carriage, comprising a base and track engaging members that are configured to engage with a corresponding track of a crane track assembly,

- a main boom, that is pivotal relative to the base of the crane carriage about a main boom pivot axis, and has a main boom tip,

- a back mast, that is pivotal relative to the base of the crane carriage about a back mast pivot axis, and has a back mast tip,

- an adjustable length arrangement between the back mast and the main boom,

- a counterweight, that is suspended from the back mast,

- a track arrangement configured to be installed on the ground and comprising a circular slew track assembly extending over at least a slew arc about a slew center, comprising at least a pair of concentric first and second slew tracks.

The crane is so large that it is commonly assembled at the location of the hoisting job, e.g. at a refinery, power plant, etc. Commonly the main boom and the back mast are each assembled from modules. The track assembly commonly comprises load spreading boards on which the tracks are mounted, so that loads are distributed in view of the allowable ground pressure.

The present invention aims to provide mobile heavy lift crane systems having an enhanced versatility and/or enhanced operational efficiency.

The present invention provides a mobile heavy lift crane system according to claim 1. Herein, the design of the crane carriage in conjunction with the design of the track arrangement, allows for an operation wherein the crane is moved over the rectilinear track assembly into a transfer position wherein the track engaging members of the first and second swivelling chassis are each arranged at a junction of the track arrangement, where the track engaging members are brought into alignment with the respective circular slew track, allowing the crane to perform slewing motion about the slew center whilst supported on the slew track assembly.

In practice, this may allow for placing the slew track assembly at the location where the actual hoisting job, e.g. of a refinery column, is to be done. Often, at this location there is limited or insufficient space available for the assembly of the crane, which often entails horizontal assembly of the main boom on the ground before bringing the assembled main boom (and any jib when present) into a raised position. In practice, the main boom, possibly with jib, may be over 100 meters long. The inventive system allows to extend the rectilinear crane track from said slew track assembly to a remote location where there is sufficient clear ground space for assembly of the crane, e.g. including horizontal assembly of the main boom, possibly with a jib. Once assembled, the crane can then be moved, with the main boom raised, over the rectilinear crane track to the slew track.

Due to the provision of junctions, and the pivoting functionality of the sets of one or more track engaging members, e.g. one or more skid members, these track engagement members can be brought into alignment with the respective circular slew track, allowing the crane to perform slewing motion about the slew center whilst supported on the slew track assembly. The pivoting can be done by actuators, e.g. hydraulic actuators, that may be integrated with the carriage but can also be embodied as separate tools that are employed for this purpose.

The swivelling functionality of the chassis of the carriage, allows for a difference of width between the rectilinear crane track and the slew track. As disclosed herein, the swivelling functionality may also allow for other configurations of the mobile heavy lift crane system.

In an embodiment, the track arrangement further comprises a rectilinear counterweight track assembly, that is configured to be arranged parallel to the rectilinear crane track assembly, preferably extending to the slew center, wherein the counterweight is configured to be moved over the rectilinear counterweight track assembly, e.g. in unison with the crane carriage of the crane moving over the rectilinear track assembly into the transfer position. The counter weight may thus assist in keeping the main boom, and possibly a jib, in raised position whilst travelling over the rectilinear crane track to the transfer position. For example, the counterweight is located at the slew center or in proximity thereof, during performance of a hoisting job with the crane. The provision of the rectilinear counterweight track assembly allows for assembly of the counterweight at a location remote from the slew track, e.g. also avoiding constraints related to the location where the actual hoisting job is to be performed. In embodiments, the rectilinear counterweight track assembly intersects the circular slew track assembly, e.g. an end portion of said semi-circular slew track assembly.

In embodiments, the counterweight is configured to be arranged in the slew center whilst performing a hoist job, and wherein a swivel is provided between the counterweight and the back mast.

In embodiments, the crane has a main hoisting assembly comprising at least one main hoist load connector, e.g. a crane hook, a main hoist cable, and a main hoist winch, wherein said main hoist winch is mounted on the crane base.

In embodiments, the slew track arrangement has a first and a second slew track, wherein the first and second rectilinear crane tracks respectively intersect the first and second slew track at two junctions.

In embodiments, the circular slew track comprises concentric first, second, and third slew tracks, wherein the crane track has first and second parallel rectilinear crane tracks, where the first crane track intersects the first slew track and the second slew track at at least one junction, and wherein the second rectilinear crane track intersects the second and third slew track at at least one junction, so that - in operation - the crane is movable over the rectilinear track assembly into a transfer position wherein the track engaging members of the first and second swivelling chassis are each arranged at a junction of the track arrangement, where the track engaging members are brought into alignment with the respective circular slew track, such that one set of track engaging members of the first swivelling chassis engages on the first slew track, the other set of engaging members of the first swivelling chassis engages on the second slew track, and one set of track engaging members of the second swivelling chassis engages on the second slew track, the other set of engaging members of the second swivelling chassis engages on the third slew track, allowing the crane to perform slewing motion about the slew center whilst supported on the slew track assembly.

In embodiments, the counterweight carriage comprises sets of one or more track engaging members, e.g. one or more skid members, each set being configured to engage with a corresponding track of the counterweight track assembly, wherein each track engaging member is pivotal about a respective vertical pivot axis, wherein the rectilinear counterweight track assembly intersects the circular slew track assembly at junctions, so that - in operation - the counterweight is movable into a transfer position wherein the track engaging members of the counterweight carriage are each arranged at a junction, where the track engaging members are brought into alignment with the respective circular counterweight track.

The present invention also provides a twin mobile heavy lift crane system comprising two cranes and a track arrangement configured to be installed on the ground to support the two cranes. Herein each of the two cranes comprises:

- a crane carriage, comprising a base, a first swivelling chassis and second swivelling chassis, the first and second swivelling chassis being adapted to support the base, each chassis being swivelling relative to the base about a corresponding first and second vertical chassis swivel axis respectively, wherein each chassis has a set of one or more track engaging members, e.g. skid members, at opposite sides of the respective swivel axis and each set being configured to engage with a corresponding track of a crane track assembly, wherein each track engaging member is pivotal relative to the respective chassis about a respective vertical pivot axis.

The track arrangement comprises a circular slew track assembly extending over at least a slew arc about a slew center, wherein the circular slew track comprising at least concentric first, second, and third slew tracks, wherein the second track is intermediate the first and third track, and wherein the crane base is configured such that one set of track engaging members of the first swivelling chassis engages on the first slew track, the other set of engaging members of the first swivelling chassis engages on the second slew track, and wherein the crane base is configured such that one set of track engaging members of the second swivelling chassis engages on the second slew track, the other set of engaging members of the second swivelling chassis engages on the third slew track.

This twin crane arrangement allows to perform hoisting jobs where both cranes are used to handle the load. The ground pressure is relatively limited as the two cranes stand on at least concentric first, second, and third slew tracks.

In a practical advantageous embodiment, the main boom pivot axes of the two cranes are aligned with one another in at least one relative position of the cranes with respect to one another on the circular slew track. This allows, for example, for identical and synchronized luffing motions of the main booms of the two crane.

In embodiments, the track arrangement further comprises a circular counterweight track assembly, that is configured to be arranged concentric with the crane track assembly, extending about the slew center, wherein each counterweight is configured to be moved over the circular rectilinear counterweight track assembly, e.g. in unison with the crane base of the crane moving over the slew track assembly during slewing of the cranes.

It will be appreciated that the crane and/or counterweight design as described in relation to the twin crane system can also be employed in the context of the provision of a rectilinear crane track as discussed above and vice versa.

The present invention also relates to a twin mobile heavy lift crane system comprising two cranes and two track arrangements each configured to be installed on the ground to support one of said two cranes, wherein each of the two cranes comprises: - a crane carriage, comprising a base, a first swivelling chassis and second swivelling chassis, the first and second swivelling chassis being adapted to support the base, each chassis being swivelling relative to the base about a corresponding first and second vertical chassis swivel axis respectively, wherein each chassis has a set of one or more track engaging members, e.g. skid members, at opposite sides of the respective swivel axis and each set being configured to engage with a corresponding track of a crane track assembly, wherein each track engaging member is pivotal relative to the respective chassis about a respective vertical pivot axis,

- a main boom, that is pivotally relative to the base of the crane carriage about a main boom pivot axis, and has a main boom tip,

- a back mast, that is pivotally relative to the base of the crane carriage about a back mast pivot axis, and has a back mast tip,

- an adjustable length arrangement between the back mast and the main boom,

- a counterweight, that is suspended from the back mast, wherein each track arrangement is configured to be installed on the ground and comprises:

- a circular slew track assembly extending over at least a slew arc about a slew center, wherein the circular slew track assemblies are spaced apart.

The present invention also relates to a mobile heavy lift crane system comprising:

- a crane comprising:

- a crane carriage, comprising a base, a first swivelling chassis and second swivelling chassis, the first and second swivelling chassis being adapted to support the base, each chassis being swivelling relative to the base about a corresponding first and second vertical chassis swivel axis respectively, wherein each chassis has a set of one or more track engaging members, e.g. skid members, at opposite sides of the respective swivel axis and each set being configured to engage with a corresponding track of a crane track assembly, wherein each track engaging member is pivotal relative to the respective chassis about a respective vertical pivot axis, - a main boom, that is pivotally relative to the base of the crane carriage about a main boom pivot axis, and has a main boom tip,

- an adjustable length arrangement between the back mast and the main boom,

- a counterweight, that is suspended from the back mast,

- a track arrangement configured to be installed on the ground and comprising:

- a circular slew track assembly extending over at least a slew arc about a slew center, comprising at least a pair of concentric first and second slew tracks.

The present invention also relates to a method for hoisting a load, wherein use is made of a crane system as described herein.

The present invention also relates to a method for installing a crane system as described herein at a hoisting site to hoist a load, wherein the method comprises:

- installing the circular slew track assembly at the hoisting site,

- installing the rectilinear crane track assembly, extending from said hoisting site to a crane assembly location,

- assembly of the crane at the assembly location, e.g. including assembly of the main boom in horizontal orientation and raising of the assembled main boom into a raised position,

- moving the assembled crane over the rectilinear crane track assembly into a transfer position wherein the track engaging members of the first and second swivelling chassis are each arranged at a junction of the track arrangement, bringing the track engaging members into alignment with the respective circular slew track, allowing the crane to perform slewing motion about the slew center whilst supported on the slew track assembly.

The present invention also relates to a mobile heavy lift crane comprising:

- a crane carriage, comprising a base, a first swivelling chassis and second swivelling chassis, the first and second swivelling chassis being arranged and configured to support the base thereon, each chassis being swivelling relative to the base about a corresponding first and second vertical chassis swivel axis, respectively, wherein each chassis has a set of one or more track engaging members, e.g. one or more skid members, at opposite sides of the respective swivel axis, each set being configured to engage with a corresponding track of a crane track assembly, wherein each track engaging member is pivotal relative to the respective chassis about a respective vertical pivot axis ,

- an adjustable length arrangement between the back mast and the main boom,

- a counterweight, that is suspended from the back mast.

A second aspect of the present invention also relates to a mobile heavy lift crane system comprising:

- a crane comprising:

- a crane carriage, comprising a base, a first chassis and second chassis, the first and second chassis being arranged and configured to support the base thereon, for example each chassis being swivelling relative to the base about a corresponding first and second vertical chassis swivel axis, respectively, wherein each chassis has a set of one or more track engaging members, e.g. one or more skid members, at opposite sides of the respective swivel axis, each set being configured to engage with a corresponding track of a crane track assembly, wherein each track engaging member is pivotal relative to the respective chassis about a respective vertical pivot axis ,

- an adjustable length arrangement between the back mast and the main boom, - a counterweight, that is suspended from the back mast,

- a track arrangement configured to be installed on the ground and comprising:

- a circular slew track assembly extending over at least a slew arc about a slew center, comprising at least a pair of concentric first and second slew tracks,

- a rectilinear crane track assembly, comprising at least of pair of parallel first and second rectilinear crane tracks, wherein the track arrangement is embodied such that the rectilinear track assembly intersects the circular slew track assembly, wherein each rectilinear crane track intersects at least one of the circular slew tracks at a junction of the track arrangement, so that - in operation - the crane is movable over the rectilinear track assembly into a transfer position wherein the track engaging members of the first and second swivelling chassis are each arranged at a junction of the track arrangement, where the track engaging members are brought into alignment with the respective circular slew track, allowing the crane to perform slewing motion about the slew center whilst supported on the slew track assembly.

As preferred, each chassis is embodied to swivel relative to the base about a corresponding first and second vertical chassis swivel axis, respectively. However, in an embodiment, the first and second chassis cannot swivel relative to the base of the carriage. It will be appreciated that this limits the versatility of the crane system, however this embodiment is still more versatile than existing heavy lift crane systems.

It will be appreciated that the crane system of the second aspect may comprise one or more features discussed herein, e.g. as described in the appended claims.

The invention will now be discussed with reference to the drawings. In the drawings:

- fig. 1 shows an example of a mobile heavy lift crane system according to the invention, wherein the crane is arranged on the circular slew track assembly,

- fig. 2 shows the crane of figure 1 from a different angle,

- fig. 3a shows a plan view of the crane system of figure 1 with the crane in positions on the rectilinear crane track and in the transfer position,

- fig. 3b illustrates the bringing of the sets of track engaging members in alignment with the slew track,

- fig. 3c illustrates an embodiment of the actuators to bring the sets of track engaging members in alignment with the slew track, - fig. 4 shows in plan view the carriage of the crane of figure 1 whilst on the rectilinear crane track,

- fig. 5 shows in plan view the carriage of the crane of figure 1 whilst on the circular slew track,

- fig. 6 shows a part of the crane of figure 1 in front view,

- fig. 7 shows hoisting of a load using the crane system of figure 1,

- fig. 8 shows the situation of figure 7 from a different angle,

- fig. 9 shows in schematic side view the hoisting of figure 7, wherein an enlarged detail shows a possible embodiment of modules of the main boom,

- fig. 10 shows in a plan view a variant of the crane system of figure 1 ,

- fig. 11a shows a possible embodiment of modules of the main boom assembly to form a section of a leg of the main boom,

- fig. 11b shows a module of the embodiment of figure 11a,

- fig. 12 shows the transportation of a module of figure 11 b by lorry,

- fig. 13 shows the counterweight of the crane system of figure 1,

- fig. 14 shows part of the crane system of figure 1,

- figs. 15a — 15i illustrate stepwise the assembly of the main boom of the crane of figure 1 ,

- fig. 16 shows an example of a twin mobile heavy lift crane system according to the invention, wherein the two cranes are arranged on the tri-track circular slew track assembly,

- fig. 17 shows the crane system of figure 16 in plan view,

- fig. 18 shows the crane system of figure 16 from a different angle,

- fig. 19 shows a part of the crane system of figure 16, generally in a front view,

- fig. 20 shows a part of the crane system of figure 16, generally in a rear view,

- fig. 21 shows the crane system of figure 16 in plan view, in a slew position different from the one in figure 17,

- fig. 22 shows in plan view and schematically an example of a twin mobile heavy lift crane system according to the invention, with a tri-track circular slew track assembly and with a rectilinear crane track assembly, wherein both cranes are shows as located on the crane track assembly,

- fig. 23 shows the crane system of figure 22, wherein the cranes have been moved into the transfer position,

- figs. 24, 25 illustrate bringing the sets of track engaging members of the cranes of figures 22, 23 into alignment with the respective circular slew track,

- fig. 26 shows in plan view the crane system of figure 22 during a hoisting job,

- fig. 27 shows another example of a crane system according to the invention during the hoisting of a load, and

- fig. 28 shows the crane system of figure 27 from a different angle. The figures 1 - 15 show an example of a mobile heavy lift crane system according to the invention. In the figure 1 the crane 1 is arranged on the circular slew track assembly 50.

The crane 1 comprises:

- a crane carriage, comprising a base 10, a first swivelling chassis 11 and second swivelling chassis 12, the first and second swivelling chassis being arranged and configured to support the base 10 thereon, each chassis 11, 12 being swivelling relative to the base about a corresponding first and second vertical chassis swivel axis, 13, 14 respectively, wherein each chassis 11, 12 has a set of one or more track engaging members, e.g. one or more skid members 15,16,17,18, at opposite sides of the respective swivel axis 13, 14, each set being configured to engage with a corresponding track of a crane track assembly, wherein each track engaging member 15,16,17,18 is pivotal relative to the respective chassis about a respective vertical pivot axis 15a, 16a, 17a, 18a,

- a main boom 20, that is pivotally relative to the base 10 of the crane carriage about a main boom pivot axis 21 , and has a main boom tip 22,

- a back mast 30, that is pivotally relative to the base 10 of the crane carriage about a back mast pivot axis 31 , and has a back mast tip 32,

- an adjustable length arrangement 40 between the back mast 30 and the main boom 20,

- a counterweight 50, that is suspended from the back mast 30,

The crane system further comprises a track arrangement that is configured to be installed on the ground and comprises:

- a circular slew track assembly 100 extending over at least a slew arc about a slew center 101, comprising at least a pair of concentric first and second slew tracks 102, 103, and

- a rectilinear crane track assembly 120, comprising at least of pair of parallel first and second rectilinear crane tracks 121, 122.

The track arrangement is embodied such that the rectilinear track assembly 120 intersects the circular slew track assembly 100, wherein each rectilinear crane track 121, 122 intersects at least one of the circular slew tracks at a junction 131, 132, 133, 134 of the track arrangement, so that - in operation - the crane 1 is movable over the rectilinear track assembly 120 into a transfer position wherein the track engaging members 15,16,17,18 of the first and second swivelling chassis 11, 12 are each arranged at a junction 131, 132, 133, 134 of the track arrangement, where the track engaging members are brought into alignment with the respective circular slew track 102, 103, allowing the crane 10 to perform slewing motion about the slew center 101 whilst supported on the slew track assembly.

The track arrangement further comprises a rectilinear counterweight track assembly 140, that is configured to be arranged parallel to the rectilinear crane track assembly 120, preferably extending to the slew center 101, wherein the counterweight 50 comprises a counterweight carriage 51 that is configured to be moved over the rectilinear counterweight track assembly 140, in unison with the crane carriage of the crane 1 moving over the rectilinear track assembly 120 into the transfer position.

The circular slew track assembly 100 is semi-circular and extends over half of a circle about the slew center 101.

The rectilinear counterweight track assembly 140 intersects the circular slew track assembly 100, here an end portion of said semi-circular slew track assembly.

As known in the art, the actual tracks of the circular slew track assembly 100, rectilinear crane track assembly 120, rectilinear counterweight track assembly 140, etc. may be arranged on load spreading boards 70 that are placed on the ground. For example, robust steel boards 70 are used.

As is known in the art, and as preferred, the tracks of the tracks of the circular slew track assembly 100, rectilinear crane track assembly 120, rectilinear counterweight track assembly 140, etc., may be embodied for skidding. For example, the track engaging members 15, 16, 17, 18 are embodied as skid members that are configured to slide over a skid surface of the tracks. For example, each track comprises a skid surface arranged between two skid rails, wherein skid actuators are engageable with one or both of said skid rails and with the carriage to advance the crane or counterweight over the respective track.

In another embodiment, the track engaging members 15, 16, 17, 18 are embodied as wheels that are configured to roll over a roll surface of the tracks, e.g. similar to railroad tracks.

As preferred, the counterweight 50 is configured to be arranged in the slew center 101 whilst performing a hoist job. As known in the art, a swivel 52 is provided between the counter weight 50 and connector 53 that extends to the back mast 30. The embodiment of figure 1 is such that the slew track arrangement has a first and a second slew track 102, 103, wherein the first and second rectilinear crane tracks 121, 122 respectively intersect the first and second slew track at two junctions.

The crane 1 has a main hoisting assembly comprising at least one main hoist load connector, e.g. a crane hook 200, a main hoist cable 201 , and a main hoist winch 202, wherein said main hoist winch is mounted on the crane base 10. As known in the art, the crane 1 here has multiple main hoist winches and associated main cables, all supporting in multiple fall arrangement the crane hook 200, e.g. having a lift capacity of over 1000 tonnes, e.g. of about 5000 tonnes in the depicted example.

The crane 1 , by way of example, has a jib 25 connected pivotally to the tip of the main boom 20 as is known in the art. The jib 25 is kept in its desired orientation by a stay mechanism, comprising a jib strut 26, a lower stay 27, and an upper stay 28. As known in the art, the strut 26 is connected at its inner end to the tip of the main boom, with the lower stay 27 extending from the outer end of the strut 26 to an inner or lower end of the main boom 20 and with the upper stay extending from said outer end of the strut 26 to the tip of the jib 25, wherein the main hoist cable depend from a sheave assembly.

The main boom 20 is, as is preferred, modular, more preferably with one or two latticed legs, e.g. as an A-frame as shown here.

The back mast 30 is, as is preferred, modular, more preferably with one or two latticed legs, e.g. as an A-frame as shown here.

The counterweight 50 may be composed of steel elements that are arranged in a cradle that is supported on carriage 51.

The figures 1 and 2 show that the counterweight carriage 50 remains on the rectilinear counterweight track assembly 140 even whilst the crane 1 has been moved onto the slew track. The swivel 52 then allows for the slew motion of the crane 1 about the slew center 101.

The crane system shown in figures 1 and 2 can be installed at a hoisting site to hoist a load using the following method:

- installing the circular slew track 100 assembly at the hoisting site, - installing the rectilinear crane track assembly 120, extending from said hoisting site to a crane assembly location,

- assembly of the crane 1 at the assembly location, e.g. including assembly of the main boom in horizontal orientation and raising of the assembled main boom into a raised position (see e.g. figures 15a-i),

- moving the assembled crane 1 over the rectilinear crane track assembly 120 into a transfer position wherein the track engaging members 15, 16, 17, 18 of the first and second swivelling chassis are each arranged at a junction 131, 132, 133, 134 of the track arrangement, bringing the track engaging members into alignment with the respective circular slew track, allowing the crane to perform slewing motion about the slew center whilst supported on the slew track assembly.

The figures 3a-c illustrate the above method, wherein the crane 1 is assembled at location A and then moved over the track 120 to the transfer position shown in figure 3a. Here, the track engaging members 15, 16, 17, 18 are moved out of there alignment with track 120 and into alignment with the track 100. In particular with skid type members 15, 16, 17, 18 this can be done rather easily, as the junction effectively needs to be no more than a break in the skid rails and an extended skid surface at the junction to allow the re-alignment of the members 15, 16, 17, 18. Due to the load, e.g. due to weight of the crane, during this alignment, actuators 170 are provided to perform the pivoting motion (see figure 3c). As preferred, skid actuator, e.g. hydraulic skid actuators 170, are used for the alignment. In embodiments, the same actuators 170 are used to skid the crane or counterweight of the associated track(s).

Figures 4 and 5 illustrate that the crane 1 cannot only be used in combination with a two track rectilinear crane assembly, or two track slew track assembly, but also with a tri-track slew track assembly which is discussed in more detail with reference to figures 16 - 26. This is in particular due to the provision of the swivel functionality of the chassis 11, 12 of the carriage of the crane 1 in combination with the pivoting functionality of the members 15, 16, 17, 18.

It is shown in figure 5 that the circular slew track assembly 100 is a tri-track having concentric circular first 101, second 102, and third slew tracks 103.

The carriage allows for positioning of the crane 1 on the slew track such that one set of track engaging members 15 of the first swivelling chassis 11 engages on the first slew track 101, the other set of engaging members 16 of the first swivelling chassis 11 engages on the second slew track 102, and one set of track engaging members 17 of the second swivelling chassis 12 engages on the second slew track 102, the other set of engaging members 18 of the second swivelling chassis 12 engages on the third slew track 103. This allows the crane to perform slewing motion about the slew center 101 whilst supported on the slew track assembly. The loads are distributed more even than with a support of the crane on just two slew tracks.

The figures 7 - 9 illustrate the hoisting of a load, e.g. a column of a refinery or other chemical plant.

Figure 10 illustrates a variant wherein a further rectilinear crane track 160 adjoins the circular slew track as an extension thereof, angled relative to the crane track 120, e.g. perpendicular to the crane track 120 as shown here.

Figure 10 illustrates that a further rectilinear counterweight track 145 extends from the slew center 101 parallel to the further rectilinear crane track 160, angled relative to the track 140, e.g. perpendicular to the track 140 as shown here.

Figures 11a, b and 12 illustrate a possible embodiment of the modules 300 of the legs of the main boom 20. Each module 300 forms half of a section of the leg, and has two longitudinal chords 301 , 302 interconnected by a latticed web 303 in one plane, preferably a top plane or a bottom plane of the module. The side planes of the module are formed by diagonal trusses 304, 305 in a zig-zag formation on the respective chord. The trusses adjoin in pairs at connection points 306 remote from the chord. The connection points 306 are provided with tabs allowing two modules to be joined with their connection points 306, e.g. by providing a pin or bolt through aligned holes in the tabs as shown here.

For example, one module 300 can be transported on a trailer of a lorry.

Figure 13 shows the counterweight 50 and the associated carriage 51 having a base 51a and four sets of one or more track engaging members 55, 56, 57, 58, e.g. one or more skid members. Each set is configured to engage with a corresponding track of the counterweight track assembly, and each track engaging member is pivotal about a respective vertical pivot axis 55a, 56a, 57a, 58a relative to the base 51a.

Figures 15a — 15i illustrate the horizontal assembly of the main boom 20 and jib 25 of the crane 1 at the assembly site, remote from the location of the slew track 100, e.g. at the end of the track 120. A regular road travelling mobile telescopic boom crane 400 is used to handle the modules 300 of the boom 25 during the assembly thereof, as well as modules of the jib 25, and other parts like the stay mechanism of the jib.

The carriage of the crane 1 is placed, e.g. assembled from components, on the track 120 at the assembly site, and then the main boom 25 is built horizontally from the carriage towards the tip of the main boom. Then the jib 25 and the related stay mechanism is assembled.

Figure 15f shows the assembly of the back mast 30, also from modules using a mobile crane 400. The back mast 30 is, as preferred, also assembled in horizontal orientation.

Figures 15g — 15i illustrate the further assembly of the crane 1. The adjustable length assembly 40, also known as luffing assembly, is provided between the tip of the back mast 30 and the tip of the main boom 20, e.g. including a winch operated cable assembly 41 and pendant 42 to the tip of the boom 20.

As shown in figure 15g, the counterweight 50 can be assembled slightly offset from the back mast still in horizontal orientation.

Once the main components of the main boom 20, back mast 30, assembly 40, main hoist, etc. are assembled, the back mast 30 is raised first and connected to the counterweight 50 that is moved into position under the tip of the mast 30. Then the assembly 40 is used to bring the main boom 20, and jib 25, into a raised position, e.g. first to allow the crane hook 200 to be fitted.

Figure 16 shows a twin mobile heavy lift crane system comprising two cranes 1 as discussed above and a track arrangement configured to be installed on the ground to support said two cranes 1.

The track arrangement comprises a circular slew track assembly extending over at least a slew arc about a slew center, wherein the circular slew track comprising at least concentric first 101, second 102, and third slew tracks 103.

As discussed with reference to figure 5 the crane base is configured such that one set of track engaging members of the first swivelling chassis engages on the first slew track, the other set of engaging members of the first swivelling chassis engages on the second slew track, and wherein the crane base is configured such that one set of track engaging members of the second swivelling chassis engages on the second slew track, the other set of engaging members of the second swivelling chassis engages on the third slew track.

It is shown that the main boom pivot axes 21 of the main booms 20 of the two cranes 1 are aligned in at least one relative position of the cranes 1 with respect to one another on the circular slew track 100.

The track arrangement further comprises a circular counterweight track assembly 180, that is configured to be arranged concentric with the circular slew track assembly 100, extending about the slew center 101. Each counterweight 50 is provided with a carriage 51 that is configured to be moved over the circular counterweight track assembly 180, e.g. in unison with the crane base of the crane 1 moving over the slew track assembly 100 during slewing of the cranes.

The figures 22 - 26 illustrate that the tri-track slew track assembly 100 is equally applicable in combination with a crane track assembly 120 having first and second parallel rectilinear crane tracks 121, 122, e.g. to allow assembly of the cranes 1 remote from the location of the slew track assembly 100.

As shown the first crane track intersects the first slew track and the second slew track at at least one junction, and the second rectilinear crane track intersects the second and third slew track at at least one junction, so that - in operation - the cranes 1 are each movable over the rectilinear track assembly into a transfer position wherein the track engaging members of the first and second swivelling chassis are each arranged at a junction of the track arrangement, where the track engaging members are brought into alignment with the respective circular slew track, such that one set of track engaging members of the first swivelling chassis engages on the first slew track, the other set of engaging members of the first swivelling chassis engages on the second slew track, and one set of track engaging members of the second swivelling chassis engages on the second slew track, the other set of engaging members of the second swivelling chassis engages on the third slew track, allowing the crane to perform slewing motion about the slew center whilst supported on the slew track assembly.

Figures 17, 28 illustrate a twin mobile heavy lift crane system comprising two cranes 1 and two track arrangements each configured to be installed on the ground to support one of said two cranes 1. The cranes 1 here are shown without jib 25. Here, each track arrangement is configured to be installed on the ground and comprises a circular slew track assembly 100 extending over at least a slew arc about a slew center, wherein the circular slew track assemblies are spaced apart, e.g. with as semi-circular slew tracks having center regions close to one another and end regions facing away from one another. The hoisting of a load can then be done by the two cranes 1 as shown herein.

Claims

C L A I M S

1. A mobile heavy lift crane system comprising:

- a crane (1) comprising:

- a crane carriage, comprising a base (10), a first swivelling chassis (11) and second swivelling chassis (12), the first and second swivelling chassis being arranged and configured to support the base (10) thereon, each chassis (11,12) being swivelling relative to the base about a corresponding first and second vertical chassis swivel axis (13,14), respectively, wherein each chassis has a set of one or more track engaging members, e.g. one or more skid members (15,16,17,18), at opposite sides of the respective swivel axis (13,14), each set being configured to engage with a corresponding track of a crane track assembly, wherein each track engaging member (15,16,17,18) is pivotal relative to the respective chassis about a respective vertical pivot axis (15a, 16a, 17a, 18a),

- a main boom (20), that is pivotal relative to the base of the crane carriage about a main boom pivot axis (21), and has a main boom tip (22),

- a back mast (30), that is pivotal relative to the base (10) of the crane carriage about a back mast pivot axis (31), and has a back mast tip (32),

- an adjustable length arrangement (40) between the back mast (30) and the main boom (20),

- a counterweight (50), that is suspended from the back mast,

- a track arrangement configured to be installed on the ground and comprising:

- a circular slew track assembly (100) extending over at least a slew arc about a slew center (101), comprising at least a pair of concentric first and second slew tracks (102,103),

- a rectilinear crane track assembly (120), comprising at least of pair of parallel first and second rectilinear crane tracks (121,122), wherein the track arrangement is embodied such that the rectilinear track assembly (120) intersects the circular slew track assembly (100), wherein each rectilinear crane track (121,122) intersects at least one of the circular slew tracks at a junction (131,132,133,134) of the track arrangement, so that - in operation - the crane (1) is movable over the rectilinear track assembly (120) into a transfer position (fig.3b) wherein the track engaging members (15,16,17,18) of the first and second swivelling chassis (11,12) are each arranged at a junction (131,132,133,134) of the track arrangement, where the track engaging members are alignable with the respective circular slew track (102,103), allowing the crane to perform slewing motion about the slew center (101) whilst supported on the slew track assembly.

2. Mobile heavy lift crane system according to claim 1 , wherein the track arrangement further comprises a rectilinear counterweight track assembly (140), that is configured to be arranged parallel to the rectilinear crane track assembly (120), preferably extending to the slew center (101), and wherein the counterweight (50) comprises a counterweight carriage (51) that is configured to be moved over the rectilinear counterweight track assembly (140), e.g. in unison with the crane carriage of the crane (1) moving over the rectilinear track assembly (120) into the transfer position.

3. Mobile heavy lift crane system according to claim 1 or 2, wherein the circular slew track assembly (100) is semi-circular and extends over half of a circle about the slew center (101).

4. Mobile heavy lift crane system according to claim 2 or 3, wherein the rectilinear counterweight track assembly (140) intersects the circular slew track assembly (100), e.g. an end portion of said semi-circular slew track assembly.

5. Mobile heavy lift crane system according to any one or more of claims 1 - 4, wherein the counterweight (50) is configured to be arranged in the slew center (101) whilst performing a hoist job, and wherein a swivel (52) is provided between the counterweight and the back mast (30).

6. Mobile heavy lift crane system according to any one or more of claims 1 - 5, wherein the crane (1) has a main hoisting assembly comprising at least one main hoist load connector, e.g. a crane hook (200), a main hoist cable (201), and a main hoist winch (202), wherein said main hoist winch is mounted on the crane base (10).

7. Mobile heavy lift crane system according to any one or more of claims 1 - 6, wherein the slew track arrangement has a first and a second slew track (102,103), wherein the first and second rectilinear crane tracks (121,122) respectively intersect the first and second slew track at two junctions.

8. Mobile heavy lift crane system according to any one or more of claims 1 - 6, wherein the circular slew track assembly (100) comprises concentric first, second, and third slew tracks (101,102,103), wherein the rectilinear crane track assembly (120) has first and second parallel rectilinear crane tracks (121,122), where the first crane track (121) intersects the first slew track (101) and the second slew track (102) at at least one junction, and wherein the second rectilinear crane track (122) intersects the second and third slew track (102,103) at at least one junction, so that - in operation - the crane (1) is movable over the rectilinear crane track assembly (120) into a transfer position in which the track engaging members (15,16,17,18) of the first and second swivelling chassis (11,12) are each arranged at a junction of the track arrangement, where the track engaging members are alignable with the respective circular slew track (101,102,103), such that one set of track engaging members (15) of the first swivelling chassis (11) engages on the first slew track (101), and the other set of track engaging members (16) of the first swivelling chassis (11) engages on the second slew track (102), and such that one set of track engaging members (17) of the second swivelling chassis (12) engages on the second slew track (102), and the other set of track engaging members (18) of the second swivelling chassis (12) engages on the third slew track (103), allowing the crane to perform slewing motion about the slew center (101) whilst supported on the slew track assembly (100).

9. Mobile heavy lift crane system according to claim 4, preferably also claim 8, wherein the track arrangement further comprises a circular counterweight track assembly (180), that is configured to be arranged concentric with the circular slew track assembly (100), extending about the slew center (101), the carriage (51) being configured to be moved over the circular counterweight track assembly (180), e.g. in unison with the crane base (10) of the crane (1) moving over the slew track assembly (100) during slewing of the crane, wherein the counterweight carriage (51) comprises sets of one or more track engaging members (55,56,57,58), e.g. one or more skid members, each set being configured to engage with a corresponding track of the rectilinear counterweight track assembly (140) and the circular counterweight track assembly (180), wherein each track engaging member (55,56,57,58) of the counterweight carriage (51) is pivotal about a respective vertical pivot axis (55a, 56a, 57a, 58a), wherein the rectilinear counterweight track assembly (140) intersects the circular counterweight track assembly (180) at junctions, so that - in operation - the counterweight (50) is movable into a transfer position in which the track engaging members (55,56,57,58) of the counterweight carriage (51) are each arranged at a junction, where the track engaging members are alignable with the respective track of the circular counterweight track assembly (180).

10. A twin mobile heavy lift crane system comprising two cranes (1) and a track arrangement configured to be installed on the ground to support said two cranes, wherein each of the two cranes (1) comprises:

- a crane carriage, comprising a base (10), a first swivelling chassis (11) and second swivelling chassis (12), the first and second swivelling chassis (11,12) being arranged and configured to support the base (10) thereon, each chassis being swivelling relative to the base about a corresponding first and second vertical chassis swivel axis (13,14) respectively, wherein each chassis has a set of one or more track engaging members, e.g. skid members (15,16,17,18), at opposite sides of the respective swivel axis (13,14) and each set is configured to engage with a corresponding track of a crane track assembly, wherein each track engaging member is pivotal relative to the respective chassis about a respective vertical pivot axis,

- an adjustable length arrangement (40) between the back mast (30) and the main boom (20), - a counterweight (50), that is suspended from the back mast, wherein the track arrangement comprises:

- a circular slew track assembly (100) extending over at least a slew arc about a slew center (100), wherein the circular slew track assembly (100) comprises at least concentric first, second, and third slew tracks (101,102,103), wherein the second track (102) is intermediate the first (101) and third track (103), and wherein the crane base (10) is configured such that one set of track engaging members (15) of the first swivelling chassis (11) engages on the first slew track (101), and the other set of engaging members (16) of the first swivelling chassis (11) engages on the second slew track (102), and wherein the crane base (10) is configured such that one set of track engaging members (17) of the second swivelling chassis (12) engages on the second slew track (102), and the other set of engaging members (18) of the second swivelling chassis (12) engages on the third slew track (103).

11. Twin mobile heavy lift crane system according to claim 10, wherein the main boom pivot axes (21) of the cranes (1) are aligned in at least one relative position of the cranes with respect to one another on the circular slew track assembly (100).

12. Twin mobile heavy lift crane system according to claim 10 or 11, wherein the track arrangement further comprises a circular counterweight track assembly (180), that is configured to be arranged concentric with the circular slew track assembly (100), extending about the slew center (101), and wherein each counterweight (50) is configured to be moved over the circular counterweight track assembly, e.g. in unison with the crane base (10) of the crane (1) moving over the circular slew track assembly (100) during slewing of the cranes.

13. Twin mobile heavy lift crane system according to any one or more of claims 10 - 12, wherein the circular slew track assembly (100) comprises concentric first, second, and third slew tracks (101,102,103), wherein the rectilinear crane track assembly (120) has first and second parallel rectilinear crane tracks (121,122), wherein the first rectilinear crane track (121) intersects the first slew track (101) and the second slew track (102) at at least one junction, and wherein the second rectilinear crane track (102) intersects the second and third slew track (102,103) at at least one junction, so that - in operation - the crane (1) is movable over the rectilinear crane track assembly (120) into a transfer position in which the track engaging members (15,16,17,18) of the first and second swivelling chassis (11,12) are each arranged at a junction of the track arrangement, where the track engaging members (15,16,17,18) are alignable with the respective slew track (101,102,103), such that one set of track engaging members (15) of the first swivelling chassis (11) engages on the first slew track (101), and the other set of engaging members (16) of the first swivelling chassis (11) engages on the second slew track (102), and such that one set of track engaging members (17) of the second swivelling chassis (12) engages on the second slew track (102), and the other set of engaging members (18) of the second swivelling chassis (12) engages on the third slew track (103), allowing the crane to perform slewing motion about the slew center (101) whilst supported on the circular slew track assembly (100).

14. Twin mobile heavy lift crane system according to claim 12 and optionally claim 13, wherein the counterweight carriage (51) comprises sets of one or more track engaging members (55,56,57,58), e.g. one or more skid members, each set being configured to engage with a corresponding track of the rectilinear counterweight track assembly (140) and the circular counterweight track assembly (180), wherein each track engaging member is pivotal about a respective vertical pivot axis (55a, 56a, 57a, 58a), wherein the rectilinear counterweight track assembly (140) intersects the circular counterweight track assembly (180) at junctions, so that - in operation - the counterweight (50) is movable into a transfer position in which the track engaging members (55,56,57,58) of the counterweight carriage (51) are each arranged at a junction, where the track engaging members are alignable with respective circular counterweight tracks of the circular counterweight track assembly (180).

15. A mobile heavy lift crane system comprising a crane (1) and a track arrangement configured to be installed on the ground to support said crane, wherein the crane (1) comprises:

- a crane carriage, comprising a base (10), a first swivelling chassis (11) and second swivelling chassis (12), the first and second swivelling chassis (11,12) being arranged and configured to support the base (10), each chassis (11,12) being swivelling relative to the base (10) about a corresponding first and second vertical chassis swivel axis (13,14) respectively, wherein each chassis (11,12) has a set of one or more track engaging members, e.g. skid members (15,16,17,18), at opposite sides of the respective swivel axis (13,14) and each set being configured to engage with a corresponding track of a crane track assembly, wherein each track engaging member (15,16,17,18) is pivotal relative to the respective chassis about a respective vertical pivot axis (15a, 16a, 17a, 18a),

- a main boom (20), that is pivotal relative to the base (10) of the crane carriage about a main boom pivot axis (21), and has a main boom tip (22),

- a back mast (30), that is pivotal relative to the base (10) about a back mast pivot axis (31), and has a back mast tip (32),

- an adjustable length arrangement between the back mast (30) and the main boom

(20),

- a counterweight (50), that is suspended from the back mast (30), wherein the track arrangement comprises:

- a circular slew track assembly (100) extending over at least a slew arc about a slew center (101), wherein the circular slew track assembly (100) comprises at least concentric first, second, and third slew tracks (101,102,103), wherein the second track (102) is intermediate the first and third track (101,103), and wherein the crane base (10) is configured such that one set of track engaging members (15) of the first swivelling chassis (11) is selectively engageable with the first or the third slew track (101,103), and the other set of engaging members (16) of the first swivelling chassis (11) is engageable with the second slew track (102), and wherein the crane base (10) is configured such that one set of track engaging members (17) of the second swivelling chassis (12) is engageable with the second slew track (102), and the other set of engaging members (18) of the second swivelling chassis (12) is engageable with the third or the first slew track (101,103) whilst the one set of track engaging members (15) of the first swivelling chassis (11) is engaged with the first or the third slew track (103).

16. A twin mobile heavy lift crane system comprising two cranes (1) and two track arrangements each configured to be installed on the ground to support one of said two cranes, wherein each crane (1) comprises:

- a crane carriage, comprising a base (10), a first swivelling chassis (11) and second swivelling chassis (12), the first and second swivelling chassis (11,12) being adapted to support the base (10), each chassis being swivelling relative to the base about a corresponding first and second vertical chassis swivel axis (13,14) respectively, wherein each chassis (11,12) has a set of one or more track engaging members, e.g. skid members (15,16,17,18), at opposite sides of the respective swivel axis (13,14) and each set being configured to engage with a corresponding track of a crane track assembly, wherein each track engaging member (15,16,17,18) is pivotal relative to the respective chassis (11,12) about a respective vertical pivot axis (15a, 16a, 17a, 18a),

- a counterweight (50), that is suspended from the back mast (30), wherein each track arrangement is configured to be installed on the ground and comprises:

- a circular slew track assembly (100) extending over at least a slew arc about a slew center (101), wherein the circular slew track assemblies (100) are spaced apart.

17. A mobile heavy lift crane system comprising:

- a crane (1) comprising:

- a crane carriage, comprising a base (10), a first swivelling chassis (11) and second swivelling chassis (12), the first and second swivelling chassis (11,12) being adapted to support the base (10), each chassis being swivelling relative to the base (10) about a corresponding first and second vertical chassis swivel axis (13,14) respectively, wherein each chassis (11,12) has a set of one or more track engaging members, e.g. skid members (15,16,17,18), at opposite sides of the respective swivel axis (13,14) and each set being configured to engage with a corresponding track of a crane track assembly, wherein each track engaging member (15,16,17,18) is pivotal relative to the respective chassis (11,12) about a respective vertical pivot axis (15a, 16a, 17a, 18a),

- a counterweight (50), that is suspended from the back mast (30),

- a track arrangement configured to be installed on the ground and comprising:

- a circular slew track assembly (100) extending over at least a slew arc about a slew center (101), comprising at least a pair of concentric first and second slew tracks (101,102).

18. Method for hoisting a load, wherein use is made of a crane system according to any one or more of claims 1 - 17.

19. Method for installing a crane system according to any one or more of claims 1 - 9 at a hoisting site to hoist a load, wherein the method comprises:

- installing the circular slew track assembly (100) at the hoisting site,

- installing the rectilinear crane track assembly (120), extending from said hoisting site to a crane assembly location,

- assembly of the crane (1) at the assembly location, e.g. including assembly of the main boom (20) in horizontal orientation and raising of the assembled main boom into a raised position,

- moving the assembled crane over the rectilinear crane track assembly into a transfer position in which the track engaging members (15,16,17,18) of the first and second swivelling chassis (11,12) are each arranged at a junction (131,132,133,134) of the track arrangement,

- bringing the track engaging members into alignment with the respective slew track (101,102), allowing the crane to perform slewing motion about the slew center (101) whilst supported on the circular slew track assembly.