NL2019514B1 - Reconfigurable crane system and methods for use thereof. - Google Patents

Abstract

A multi configurations crane system comprises a crane base having a main boom pivot structure adapted to secure thereto a main boom of the crane and providing a horizontal 5 main boom pivot axis for the main boom relative to the crane base. A main boom system is adapted to provide multiple main boom configurations and comprises: - a lower main boom section having a first end connectable to said main boom pivot structure of the crane base to allow for luffing of the main boom in a luffing plane, and a second end opposite said first end, 10 - a top main boom section adapted to suspend a load from the main boom, e.g. comprising an assembly of one or more sheaves for one or more winch driven cables from which said load is suspended, - multiple lattice insert sections adapted to be inserted as a single strand of multiple of said lattice insert sections in said main boom.

Description

Patent center

Θ 2019514

(2?) Application number: 2019514 (22) Application submitted: 8 September 2017

Int. CL:

B66C 23/70 (2018.01) B66C 23/76 (2018.01)

0 Application registered: 0 Patent holder (s): March 19, 2019 Mammoet Engineering B.V. in SCHIEDAM. 0 Request published: - 0 Inventor (s): Pieter Maria Stoof in BREDA. 0 Patent granted: March 19, 2019 0 Authorized representative: 0 Patent issued: ir. J.C. Volmer et al. In Rijswijk. May 22, 2019

RECONFIGURABLE CRANE SYSTEM AND METHODS FOR USE THEREOF.

5 ^ A multi configurations crane system comprises a crane base having a main boom pivot structure adapted to secure thereto a main boom of the crane and providing a horizontal main boom pivot axis for the main boom relative to the crane base. A main boom system is adapted to provide multiple main boom configurations and comprises:

- a lower main boom section having a first end connectable to said main boom pivot structure of the crane base to allow for luffing or the main boom in a luffing plane, and a second end opposite said first end,

- a top main tree adapted to suspend a load from the main tree, e.g. including an assembly or one or more sheaves for one or more winch driven cables from which said load is suspended,

- multiple lattice insert sections adapted to be inserted as a single beach or multiple or said lattice insert sections in said main tree.

NL B1 2019514

This patent has been granted regardless of the attached result of the research into the state of the art and written opinion. The patent corresponds to the documents originally submitted.

P33280NL00 / HJB

RECONFIGURABLE CRANE SYSTEM AND METHODS FOR USE THEREOF.

The present invention relates to multi configurations, crane systems and use names.

US8177081 discloses a multi configurations crane system including:

- a crane base having a main boom pivot structure adapted to secure thereto a main boom of the crane and providing a horizontal main boom pivot axis for the main boom relative to the crane base,

- a main boom system adapted to provide multiple main boom configurations, said main boom system including:

- a lower main boom section having a first end connectable to said main boom pivot structure of the crane base to allow for luffing or the main boom in a luffing plane, and a second end opposite said first end,

- a top main tree adapted to suspend a load from the main tree, e.g. including an assembly or one or more sheaves for one or more winch driven cables from which said load is suspended,

- multiple lattice insert sections adapted to be inserted in said main tree, said said lattice insert sections each include a longitudinal axis, said said multiple lattice insert sections include:

- a set of multiple first insert sections, each having a first cross-sectional size providing a first moment of inertia in the luffing plane and a second moment of inertia in a plane through said longitudinal axis and perpendicular to said luffing plane,

- a set of multiple second insert sections, each having a second cross-section size different from said first cross-sectional size or said first insert sections and providing a third moment of inertia in the luffing plane that is different from said first moment of inertia in the luffing plane and providing a fourth moment of inertia in a plane through said longitudinal axis and perpendicular to said luffing plane that is different from said second moment of inertia in a plane through said longitudinal axis and perpendicular to said luffing plane.

In US8177081 it is proposed to have a first configuration of the crane, the main boom is composed of the lower main boom section, the top main boom section, and a single beach or multiple first insert sections between said lower and top main boom sections.

-2It is explained in US 8177081 that for some hoist jobs and situations increased strength is desired. Therefore a second configuration is proposed, the main tree is composed of the lower main tree section, the top main tree section, a lower region of two strands of first insert sections are arranged in parallel, an upper region of a single beach or second insert sections is present, a lower cross-beam that connects the lower ends of both first insert section strands to the lower main tree section, and an upper cross-beam that connects the upper ends of the two first insert section strands to the single second insert section beach.

A first aspect of the present invention aims to provide an alternative or improved main boom system.

This aim has been achieved by a crane system according to claim 1.

In the inventive crane system the multiple lattice insert sections are adapted to be inserted as a single beach or multiple or lattice insert sections in the main boom.

The lattice insert sections each include a longitudinal axis. The lattice insert sections are each composed of longitudinally extending corner chords that are spaced from one another and are each parallel to the longitudinal axis of the insert section. Each of the corner chords is arranged at a corner or a cross-section of the insert section perpendicular to the longitudinal axis so that each pair or adjacent corner chords defines a side plane or the insert section. Each corner chord is provided along the length with joint members.

Each lattice insert section is further composed of elongated rigid bracing members, e.g., hollow tubular steel bracing rods. These elongated rigid bracing members extend in the side planes of the insert section, each elongated rigid bracing member has one end connected to a joint member on one corner chord and has its other end connected to a joint member on the other corner chord or the pair or corner chords.

In parallel axial end faces or each insert section the axial ends of the corner chords are provided with connector members, which connector members are adapted to interconnect the insert section to adjoining sections of the main tree.

In the inventive crane it is envisaged that the multiple lattice insert sections are adapted to be inserted as a single beach or multiple or said lattice insert sections in said main boom.

-3The mentioned multiple lattice insert sections include:

- a set of multiple first insert sections, each having a first cross-sectional size providing a first moment of inertia in the luffing plane and a second moment of inertia in a plane through said longitudinal axis and perpendicular to said luffing plane, and

- a set of multiple second insert sections, each having a second cross-sectional size greater than said first cross-sectional size or said first insert sections and providing a third moment of inertia in the luffing plane that is greater than said first moment of inertia in the luffing plane and providing a fourth moment of inertia in a plane through said longitudinal axis and perpendicular to said luffing plane that is greater than said second moment of inertia in a plane through said longitudinal axis and perpendicular to said luffing plane.

In the inventive crane section, at least the second insert sections are modular as each connection or an elongated rigid bracing member to a joint member on a corner chord or the second insert section is effected by a releasable fastener allowing for a disassembled transport fashion of the second insert sections are the second insert sections have been disassembled into individual corner chords and individual elongated rigid bracing members, for example said releasable fastener being a fastener pin that is insertable through aligned holes in the joint member and the end of the elongated rigid bracing member.

For example individual corner chords and / or individual elongated rigid bracing members are dimensioned to be transported in a 40 ft. ISO freight container.

The inventive crane section also includes multiple lattice transition sections, each including a longitudinal axis and including corner chords that extend non-parallel to this longitudinal axis. Each transition section has a first axial end face and a cross-section perpendicular to the longitudinal axis that corresponds to the first cross-sectional size and is provided, said first axial end face, with connector members at axial ends of the chords of the transition section so as to allow for connection to one or said first insert sections. Each transition section has a second axial end face after a cross-section perpendicular to the longitudinal axis that corresponds to the second cross-sectional size and is provided, said second axial end face, with connector members at axial ends of the chords ofthe transition section so as to allow for connection to one of the second insert sections.

As will be appreciate by the skilled person the second insert sections have greater resistance to buckling than the first insert sections. Due to the structure of the second insert sections the load bearing chords and bracing members are located in the corners and related

-4side planes of the second insert sections which allows to make optimum use of these components in view of strength and resistance to buckling. At the same time the weight of each insert section is kept relatively low. Due to the modular construction or at least the second insert sections, these second insertion section can be envisaged with cross-sectional dimensions that would rule out transport by road if they were non-modular or equally modular design.

In vary the second insert sections may have a square or rectangular cross section, so with four corner chords, with the dimension of the cross section in width and in depth exceeding 3 meters. For example the second insert section may have a square cross-section or 4x4, 5x5, 6x6, 7x7, 8x8, or even 9x9 meters in practical execution. Of course rectangular cross-sections, one of the width and depth has a value between 3 and 9 meters and the other of the width and depth has a value of between 3 and 9 meters may also be composed within the scope of claim 1. A rectangular cross-section may have a width that exceeds the depth, the depth is generally in the plane of luffing motion. Equally the cross-section may be another polygonal cross-section providing more than four side planes, e.g., six or eight side planes.

Most preferably each second insert section only consists of said corner chords and said elongated rigid bracing elements configured to be releasably fastened between corner chords in said side planes or the section as far as the load bearing function or the second insert section is concerned.

The increased buckling resistance provided by the single beach or second insert sections for example allows to perform heavy load jobs with the main boom according to the second configuration. Herein the beach or second insert sections is located in the region where the highest buckling load is expected during the job. Lighter load jobs can then be performed with the main tree according to the first configuration.

In the second configuration this single beach or second insert section is far more effective than the proposal of dual strands as in US8177081 in several aspects. For example the weight of the second insert sections of the inventive proposal to achieve a certain buckling resistance is far less than would be achieved if embodied to US8177081 as in the latter much of the structure is present close to the central longitudinal axis so not contributing in any significant manner of resistance against buckling. The reduced relative weight has an impact on the effective hoisting capability of the crane in said second configuration, but also

-5on shipping costs from the crane to the site of the hoisting jobs, to the assembly of the crane, etc.

In variant the first insert sections are non-modular, e.g. as their cross-sectional dimensions do not interfere with road transportation. For example a four side plane, square or rectangular, first insert section has no cross-sectional width and depth beyond 2.5 meters.

So in the first insert sections have the elongated rigid bracing members permanently secured to the joint members of the corner chords, e.g. by welding.

Within all the corner chords within a first insert section and / or within a second insert section have the same cross-section. In other expands the corner chords within a first insert section and / or within a second insert have different cross-sections, for example corner chords located at the lower side of the main tree, seen in the luffing plane, being or larger cross-section than corner chords in the same insert section at the upper side of the main tree.

In variant the multiple lattice transition sections are also of modular design. Herein the transition sections have corner chords that extend non-parallel to the longitudinal axis and form side planes of the transition section. In these side planes elongated rigid bracing members are envisaged each having ends, each connection of an end of an elongated rigid bracing member to a joint member on a corner chord of the transition section is effected by a releasable fastener allowing for a disassembled transport mode of the transition sections of these sections have been disassembled into individual corner chords and individual elongated rigid bracing members, for example said releasable fastener being a fastener pin that is insertable through aligned holes in the joint member and the end of the elongated rigid bracing member.

The inventive crane system may be or benefit, for example, for use at one site following a series or hoist job is performed in succession. Often, in such a series or jobs, one or a small number of hoisting jobs involve the hoisting of a load that is significantly larger or a load which has been hoisted from and / or a location which is significantly further from the position of the crane base than the remaining hoisting jobs. A commonly applied approach is then to provide a crane system designed for the heavy job and perform the entire series with said crane. However, the same crane operator may also be involved in hoisting jobs at another, second location that require the high capacity.

-6The present invention, for example, allows to perform one or more heavy jobs at the first location with the crane system in the second configuration, and then remodel said crane boom in the first configuration to perform the lesser demanding jobs at said first location. The disassembled second insert sections can then be easily shipped to the second location, e.g. by road, train, and / or boat, and assembled there for use in conjunction with another crane.

The skilled person will appreciate that the inventive crane system allows for a large variety of methods or handle the crane system.

The invention also relates to a crane system in which the crane has a so-called back mast, and the inventive approach is applied to a back mast, possibly also in the same crane for the main boom as well.

For example the crane according to the invention comprises a crane base, a main boom and a back mast.

The crane base may be the chassis or a crawler crane, and / or a foot assembly or a ringer crane.

The crane base optionally comprises rollers and / or slide shoes. Optionally, the crane base can absorb both pushing forces and pulling forces from the main boom and / or back mast or the crane.

Optionally, the crane base comprises multiple outriggers, e.g. at least four outriggers, optionally at least eight outriggers. The outriggers are arranged at a distance (at least in horizontal direction) from the lower ends of the masts.

In an embodiment the main boom has, in the second configuration, a length of more than 50 meters, e.g. about 80 meters. For example the beach or second insert sections has a length between 20 and 40 meters.

In an embodiment the main boom and back mast are pivotally connected to the crane base. Optionally, the back mast has a length which is more than 50%, preferably more than 75% of the length of the main tree, preferably less than the length of the main tree.

If the inventive approach is used for both the main boom and the back mast of the crane, and both are brought into the aforementioned second configuration to provide enhanced buckling

-7 resistance, a significant overall increase in hoisting capacity can be achieved, which cannot be achieved if only the cross sectional size of the main tree would be increased.

In embodiment the corner chords have a circular cross-section.

In another embodiment, e.g. in the second insert sections, the corner chords, or at least some corner chords, have an octagonal cross section. The octagonal cross sectional shape is advantageous with respect to bending stiffness and resistance to buckling. It also allows an easy connection to the elongated rigid bracing members.

A second aspect of the present invention relates to a multi configurations crane system including:

- a crane base having a main boom pivot structure adapted to secure thereto a main boom of the crane and providing a horizontal main boom pivot axis for the main boom relative to the crane base,

- a main boom, for example, including:

- a lower main boom having a first end connectable to said main boom pivot structure of the crane base to allow for luffing of the main boom in a luffing plane, and a second end opposite said first end,

- a top main tree adapted to suspend a load from the main tree, e.g. including an assembly or one or more sheaves for one or more winch driven cables from which said load is suspended,

- multiple lattice insert sections adapted to be inserted as a single beach or multiple parallel strands or multiple or said lattice insert sections in said main tree,

- a back mast system to form a back mast from which a ballast load is suspended during a hoisting job, the back mast system is adapted to provide multiple back mast configurations, said back mast system including:

- a lower back mast section having a first end connectable to a back mast pivot structure of the crane base to allow for variation of the angle of the back mast in a back mast pivot plane, and a second end opposite said first end,

- a top back mast section adapted to suspend a ballast load from the back mast, e.g. including an assembly or one or more sheaves for one or more winch driven cables from which said ballast load is suspended,

- multiple lattice insert sections adapted to be inserted as a single beach or multiple or said lattice insert sections in said back mast, said said lattice insert sections each include a longitudinal axis, and the lattice insert sections are each composed of longitudinally extending corner chords that are spaced from one another and are each parallel to said longitudinal axis of the insert section, each of said corner chords being arranged at a corner of a cross-section of the insert section perpendicular to said longitudinal axis so that each pair of adjacent corner chords defines a side plane of the insert section, each corner is provided along the length with joint members, and the insert section is further composed of elongated rigid bracing members, said elongated rigid bracing members extend in said side planes or the insert section, each elongated rigid bracing member having one end associated with a joint member on one co rner chord and having another end connected to a joint member on the other corner chord or said pair of corner chords, while - in parallel axial end faces or each insert section - axial ends or said corner chords are provided with connector members, which connector members are adapted to interconnect said insert section to adjoining sections of the back mast, said said multiple lattice insert sections include:

- a set of multiple first insert sections, each having a first cross-sectional size providing a first moment of inertia in the back mast pivot plane and a second moment of inertia in a plane through said longitudinal axis and perpendicular to said back mast pivot plane ,

- a set of multiple second insert sections, each having a second cross-sectional size greater than said first cross-sectional size or said first insert sections and providing a third moment of inertia in the luffing plane that is greater than said first moment of inertia in the back mast pivot plane and providing a fourth moment of inertia in a plane through said longitudinal axis and perpendicular to said back mast pivot plane that is greater than said second moment of inertia in a plane through said longitudinal axis and perpendicular to said back mast The second insert sections are modular as each connection or an elongated rigid bracing member to a joint member on a corner chord or the second insert section is effected by a releasable fastener allowing for a disassembled transport mode of the second insert sections are the second insert sections have been disassembled into individual corner chords and individual elongated rigid bracing m embers, for example said releasable fastener being a fastener pin that is insertable through aligned holes in the joint member and the end of the elongated rigid bracing member,

- multiple lattice transition sections, each including a longitudinal axis and including corner chords that extend non-parallel to said longitudinal axis, each transition section has a first axial end face, a cross-section perpendicular to the longitudinal axis that says to the first cross-sectional size and is provided, at said first axial end face, with connector members at axial ends of the chords of the transition section so as to allow for connection to one or said first insert sections, and are each transition section further has at a second axial end face after a cross-section perpendicular to the longitudinal axis that corresponds to the second cross-sectional size and provided, at said second axial end face, with connector members at axial ends of the chords of the transition section so as to allow for connection to one or said second insert sections, the back mast system providing a first configuration of the crane:

- the back mast is composed of said lower back mast section, said top back mast section, and a beach or multiple first insert sections between said lower and top back mast sections, and the back mast system providing a second configuration of the crane is:

- the back mast is composed of said lower back mast section, said top back mast section, and a single beach or multiple second insert sections and a single first insert section or a single beach or multiple first insert sections, where one of said lattice transition sections is mounted at one end or said single beach or multiple second insert sections and another is one of said lattice transition sections is mounted at the other end or said single beach.

A third aspect of the present invention relates to a multi configurations crane system including:

- a crane base having an A - frame main boom pivot structure adapted to secure thereto an A - frame main boom of the crane and providing a horizontal main boom pivot axis for the A frame main boom relative to the crane base,

- an A - frame main boom system adapted to provide multiple main boom configurations, said main boom system including:

- a lower main boom structure having a first end connectable to said main boom pivot structure of the crane base to allow for luffing or the main boom in a luffing plane, and a second end opposite said first end,

- a top main tree structure adapted to suspend a load from the main tree, e.g. including an assembly or one or more sheaves for one or more winch driven cables from which said load is suspended,

- two A-frame leg structures, each having a lower end connectable to the lower main tree structure and having a top end connectable to the top main tree structure,

- multiple lattice insert sections adapted to be inserted as a single beach or multiple or said lattice insert sections in each of the two A-frame lay structures or said main tree, said said lattice insert sections each included a longitudinal axis, and on the lattice insert sections are each composed of longitudinally extending corner chords that are spaced from one another and are each parallel to said longitudinal axis of the insert section, each of said corner chords being arranged at a corner or a cross-section of the insert section perpendicular to said longitudinal axis so that each pair of adjacent corner chords defines a side plane of the insert section, each corner chord is provided along the length with joint members, and with the insert section is further composed of elongated rigid bracing members, said said elongated rigid bracing members extend into said side planes of the insert section, each elongated rigid bracing member having one end the reof connected to a joint member on one corner chord and having another end associated with a joint member on the other corner chord or said pair of corner chords, holding - in parallel axial end faces or each insert section - axial ends or said corner chords are provided with connector members, which connector members are adapted to interconnect said insert section to adjoining sections of the main tree, said multiple lattice insert sections include:

- a set of multiple first insert sections, each having a first cross-sectional size providing a first moment of inertia in the luffing plane and a second moment of inertia in a plane through said longitudinal axis and perpendicular to said luffing plane,

- a set of multiple second insert sections, each having a second cross-sectional size greater than said first cross-sectional size or said first insert sections and providing a third moment of inertia in the luffing plane that is greater than said first moment of inertia in the luffing plane and providing a fourth moment of inertia in a plane through said longitudinal axis and perpendicular to said luffing plane that is greater than said second moment of inertia in a plane through said longitudinal axis and perpendicular to said luffing plane, present, at least the second insert sections are modular as each connection or an end or an elongated rigid bracing member to a joint member on a corner chord or the second insert section is effected by a releasable fastener allowing for a disassembled transport mode or the second insert sections the second insert sections have been disassembled into individual corner chords and individual elongated rigid bracing members, for example said releasable fastener being a fastener pin that is

-11insertable through aligned holes in the joint member and the end of the elongated rigid bracing member,

- multiple lattice transition sections, each including a longitudinal axis and including corner chords that extend non-parallel to said longitudinal axis, each transition section has a first axial end face, a cross-section perpendicular to the longitudinal axis that says to the first cross-sectional size and is provided, at said first axial end face, with connector members at axial ends of the chords of the transition section so as to allow for connection to one or said first insert sections, and are each transition section further has at a second axial end face after a cross-section perpendicular to the longitudinal axis that corresponds to the second cross-sectional size and provided, at said second axial end face, with connector members at axial ends of the chords of the transition section so as to allow for connection to one or said second insert sections, the A-frame main boom system providing a first configuration of the crane:

- the A-frame main tree is composed of said lower main tree structure, said top main tree structure, and said two A-frame lay structures which are each composed of a single strand or multiple first insert sections (11) between said lower and top main boom structures, and the main boom system providing a second configuration of the crane regard:

- the A - frame main tree is composed of said lower main tree structure, said top main tree structure, and said two A - frame lay structures which are each composed of a single lower beach or multiple second insert sections and a single upper beach or multiple first insert sections, said one or said lattice transition sections is mounted between said upper and lower strands, and said another one of said lattice transition sections is mounted at a lower end or said lower beach connection said lower beach to said lower main tree structure or, optionally to a first insert section between said lattice transition section and said lower main tree structure.

The invention will be described in more detail below under reference to the drawing, in which in a non-limiting manner example of the invention will be shown. The drawing shows in:

FIG. 1 a possible embodiment of a crane system according to the invention, with the main boom system and a back mast system in the first configuration,

FIG. 2 the embodiment of Fig. 1, with the main boom system and the back mast system in the second configuration thereof.

-12fig. 1 shows a crane 1 which is arranged at a hoisting location.

The crane 1 comprises a crane base 2, a main boom 10 and a back mast 20.

For example, in the embodiment of Fig. 1, the crane base 2 is the chassis or a crawler crane. Outriggers are not shown in Fig. 1 for reasons of clarity, but they may be provided as needed.

The main boom 10 and the back mast 20 are connected via a guy wire arrangement 3.

The crane 1 in this example further comprises one or more ballasts 4, 5.

The main boom 10 and the back mast 20 are each privately connected to the crane base 2.

A crane hook 6 is suspended from the top of the main boom 10 by hoisting line 7. When a load is hoisted, the load is connected to the crane hook 7, connecting the load to the main boom 10 via the hoisting line 7 .

As illustrated in the example of Fig. 1, the back mast 20 may have a length of more than 50% of the length of the main boom 20.

In the embodiment of Fig. 1, the main tree 10 comprises a lower main tree section 12 and a top main tree section 13.

In the embodiment of Fig. 1, the back mast 20 comprises a lower back mast section 22 and a top back mast section 23. The lower back mast section 22 has a first end 22a which is connected to the crane base 2 and a second end 22b.

In accordance with a possible embodiment of the method according to the invention, a first hoisting job in the series or hoisting jobs is carried out using the crane 1 in the configuration of fig. 1. The first hoisting job involves attaching a first load to the main boom 10 of the crane 1, and further hoisting the first load. After hoisting the first load, the first load is disconnected from main boom 10 of the crane 1.

As will be appreciated the inventive crane system can be brought in multiple alternative configurations, including the configuration illustrated in figure 2, both the main boom system and the back mast system have been brought in the second configuration as explained read. Herein both the main boom 10 and the back mast 20 have a region formed by second insert sections that provide a significant increase in strength, especially in view of

-13buckling, and - as explained read - at a relatively low weight so as to obtain an optimized load handling capacity of the crane 1 in this configuration.

It will be appreciated that in alternative embodiment the crane 1 for example has a main boom system in the second configuration in combination with a back mast system in the first configuration ne, or in another alternative configuration the main boom system is the first configuration and the back mast system in the second configuration.

The crane base 2 has a main boom pivot structure 2a that is adapted to secure thereto the main boom 10 of the crane and provides a horizontal main boom pivot axis for the main boom relative to the crane base so that the main boom 10 can perform a luffing motion in a vertical luffing plane.

As will be appreciated the main boom system is adapted to provide multiple main boom configurations, including a first configuration illustrated in figure 1 and a second configuration shown in figure 2.

The lower main boom section 12 having a first end 12a connectable to the main boom pivot structure 2a of the crane base 2 to allow for luffing of the main boom in a luffing plane, and a second end 12b opposite this first end 12a.

The top main tree section 13 is adapted to suspend a load from the main tree, e.g. including an assembly or one or more sheaves 13a for one or more winch driven cables from which said load is suspended.

In the first configuration the main tree 10 is composed of the lower main tree section 12, the top main tree section 13, and a single strand or multiple first insert sections 11 between the lower and top main tree section 12, 13.

The first insert sections 11 are embodied as lattice insert sections and adapted to be inserted as a single beach or multiple or lattice first insert sections 11 in the main tree 10.

As generally known in the art, the first insert sections 11 may be or non-modular design, all components being rigid and permanently jointed. Other modular or foldable designs or the first insert sections are also possible, e.g. to facilitate transportation.

The lattice first insert sections each include a longitudinal axis.

-14 In this example it is envisaged that the latte first insert sections are of a square crosssectional shape, as is rather common in the art, e.g. with a width and depth of the insert section or 2.5 meters.

The lattice insert sections 11 are each composed of four longitudinally extending corner chords that are spaced from one another and are each parallel to the longitudinal axis of the insert section. Each of said corner chords is arranged at a corner of the square cross-section of the insert section 11 as a perpendicular to said longitudinal axis so that each pair of adjacent corner chords defines a side plane or the insert section 11.

Each corner chord is provided along the length with joint members. Each insert section 11 is further composed of elongated rigid bracing members, both diagonal bracing members and transverse bracing members (so at an incline to the chords and perpendicular to the chords). These elongated rigid bracing members extend in the side planes or the insert section.

Each elongated rigid bracing member of the insert sections 11 has one end connected to a joint member on one corner chord and has another end connected to a joint member on the other corner chord or said pair of corner chords.

As is common in the field, in parallel axial end faces or each insert section 11, axial ends of the four corner chords are provided with connector members, which connector members are adapted to interconnect said insert section 11 to adjoining sections, so either another insert section 11, the top section 13, or the lower section 12, or the main boom 10.

It will be appreciated that in the set of multiple first insert sections 11, each first insert section 11 has a first cross-sectional size, here defined by the width and the depth of the square cross-section (with the depth seen in the luffing plane between the front and back side planes and with the width seen between the two lateral side planes of the sections 11), providing a first moment of inertia in the luffing plane and a second moment of inertia in a plane through the longitudinal axis and perpendicular to the luffing plane.

It will be appreciated that the main tree 10 can be made to length by inclusion of the desired number of first insert sections 11.

-15 Figure 2 illustrates the reconfiguration of the crane 1, the main boom 10 is composed of the lower main boom section 12, the top main boom section 13, and a single lower beach or multiple second insert sections 31 and a single upper beach or multiple first insert sections 11. A lattice transition section 34 is mounted between these upper and lower strands. Another lattice transition sections 32 is mounted at the lower end of the lower beach and connects to a first insert section 11 that is mounted between this lower lattice transition section 32 and the lower main tree section 12.

The multiple lattice second insert sections 33 are adapted to be inserted as a single beach or multiple or said lattice second insert sections 33 in the main tree 10.

The second insert sections 33 each include a longitudinal axis.

In this example it is envisaged that the latte second insert sections 33 are of a square cross-sectional shape, as is rather common in the art, but with a width and depth of the insert section 31 exceeding the width and depth of the cross section of the first insert sections 11. For example the width and depth of the second insert section may be 4x4, 5x5, 6x6 meters.

The lattice insert sections 31 are each composed of four longitudinally extending corner chords that are spaced from one another and are each parallel to the longitudinal axis of the insert section 31. Each of said corner chords is arranged at a corner of the square crosssection of the insert section 31 a perpendicular to said longitudinal axis so that each pair or adjacent corner chords defines a side plane of the insert section 31.

Each corner chord is provided along the length with joint members. Each insert section 31 is further composed of elongated rigid bracing members, both diagonal bracing members and transverse bracing members (so at an incline to the chords and perpendicular to the chords). These elongated rigid bracing members extend into the side planes or the insert section 31.

Each elongated rigid bracing member of the insert sections 31 has one end connected to a joint member on one corner chord and has another end connected to a joint member on the other corner chord or said pair of corner chords.

As is common in the field, in parallel axial end faces or each insert section 31, axial ends of the four corner chords are provided with connector members, which connector members are

-16adapted to interconnect said insert section 31 to adjoining insert sections 31 or to one of the transition sections 32, 34 of the main boom system.

These large cross-section second insert sections 31 are each modular as each connection or an end or an elongated rigid bracing member to a joint member on a corner chord or the second insert section 31 is effected by a releasable fastener allowing for a disassembled transport mode of the second insert sections 31 in the second insert sections have been disassembled into individual corner chords and individual elongated rigid bracing members. In a preferred embodiment the releasable fastener is a fastener pin that is insertable through aligned holes in the joint member and the end of the elongated rigid bracing member.

So, the multiple second insert sections 31 of the main boom system each have a second cross-sectional size that is significantly greater than the first cross-sectional size or each of the first insert sections 11 of the main boom system. Each second insert section 31 has a third moment of inertia in the luffing plane that is greater than said first moment of inertia in the luffing plane of the first insert sections 11 and a fourth moment of inertia in a plane through said longitudinal axis and perpendicular to said luffing plane that is greater than the second moment of inertia or the first insert sections 11 in a plane through said longitudinal axis and perpendicular to said luffing plane.

Due to the open centered structure of the second insert sections 31, with corner chords and bracing members all located in the side planes and corners and with a simple, relatively lightweight, and easily assembled and disassembled design, an optimized load handling capacity of the main boom 10 and thus of the crane 1 can be achieved with a single beach or second insert sections 31 in the main boom. As explained this is considered beneficial about a dual parallel beach design.

In another configuration of the main tree 10, the entire region between the top main tree section 13 and lower main tree section 12 is made up by a single beach or second insert sections 31 with provision of the mentioned lattice transition sections 32, 24 at the lower and upper end of said single strand or sections 31.

The lattice transition sections 32, 34 or the main boom system each include a longitudinal axis. In these sections 32, 34 the four corner chords extend non-parallel to this longitudinal axis as the general shape formed by side planes or the section 32, 34 resembles a truncated pyramid. Each transition section 32, 34 has a first axial end face from a cross-section

-17perpendicular to the longitudinal axis that conforms to the first cross-sectional size of the first insert sections 11 and is provided, said said first axial end face, with connector members at axial ends of the chords of the transition section so as to allow for connection to one of said first insert sections 11. Each transition section 32, 34 further has a second axial end face thereafter a cross-section perpendicular to the longitudinal axis that is appropriate to the second cross-sectional size of the second insert sections 31 and is provided, at said second axial end face, with connector members at axial ends of the chords of the transition section so as to allow for connection to one of said second insert sections 31.

As explained above the inventive approach discussed above in the context of the main boom 10 of a crane, may also be implemented in a back mast 20 or a crane having one or more back masts in combination with a main boom 10. Again the result is a multi-configurations design, now of the back mast 20 that allows to effectively change the practical design of the back mast 20, eg to include a single beach or large cross-section second insert sections in the back mast to enhance the strength, and in particular the buckling resistance of the back mast 20.

In figure 1 the back mast 20 is illustrated in its first configuration. Herein the back mast 20 is composed of a lower back mast section 22, a top back mast section 23, and a single strand or multiple first insert sections 21 between these lower and top back mast sections 22, 23.

The back mast is pivotal relative to the crane base 2 about a pivot structure 2b providing a horizontal pivot axis. Here said axis is parallel to the pivot axis of the main tree, so that the luffing plane and a back mast pivot plane coincide. In some cranes two back masts are provided that diverge from the crane base 2, with non-parallel pivot axes so that each back mast has its own back mast pivot plane that does not coincide with the main boom pivot axis.

As generally known in the art, the first insert sections 21 may be or non-modular design, all components being rigid and permanently jointed. Other modular or foldable designs or the first insert sections are also possible, e.g. to facilitate transportation.

The lattice first insert sections 21 each include a longitudinal axis.

In this example it is envisaged that the latte first insert sections are of a square crosssectional shape, as is rather common in the art, e.g. with a width and depth of the insert section or 2.5 meters.

The lattice insert sections 21 are each composed of four longitudinally extending corner chords that are spaced from one another and are each parallel to the longitudinal axis of the

-18 insert section. Each of said corner chords is arranged at a corner of the square cross-section of the insert section 21 as a perpendicular to said longitudinal axis so that each pair of adjacent corner chords defines a side plane or the insert section 21.

Each corner chord is provided along the length with joint members. Each insert section 21 is further composed of elongated rigid bracing members, both diagonal bracing members and transverse bracing members (so at an incline to the chords and perpendicular to the chords). These elongated rigid bracing members extend in the side planes or the insert section.

Each elongated rigid bracing member of the insert sections 21 has one end connected to a joint member on one corner chord and has another end connected to a joint member on the other corner chord or said pair of corner chords.

As is common in the field, in parallel axial end faces or each insert section 21, axial ends of the four corner chords are provided with connector members, which connector members are adapted to interconnect said insert section 21 to adjoining sections, so either another insert section 21, the top section 23, or the lower section 22, or the back mast 20.

It will be appreciated that in the set of multiple first insert sections 21, each first insert section 21 has a first cross-sectional size, here defined by the width and the depth of the square cross-section (with the depth seen in the back mast pivot plane, here coinciding with the luffing plane, between the front and back side planes and with the width seen between the two lateral side planes of the sections 21), providing a first moment of inertia in the back mast pivot plane and a second moment of inertia in a plane through the longitudinal axis and perpendicular to the back mast pivot plane.

It will be appreciated that the back mast 20 can be made to length by inclusion of the desired number of first insert sections 21.

Figure 2 illustrates the reconfiguration of the crane 1, the back of the mast 20 is composed of the lower back mast section 22, the top back mast section 23, and a single beach or multiple second insert sections 41 and here a beach of just one first insert section 21. It will be appreciated that for a longer back mast also a single beach or multiple first insert sections 21 can be integrated in the back mast in combination with the beach or sections 41.

-19A lattice transition section 44 is mounted between these upper and lower strands. Another lattice transition sections 42 is mounted between the beach or insert sections 41 and the top back mast section 23.

The multiple lattice second insert sections 41 are adapted to be inserted as a single beach or multiple or said lattice second insert sections 41 in the back mast 20.

The second insert sections 41 each include a longitudinal axis.

In this example it is envisaged that the lattice second insert sections 41 are of a square cross-sectional shape, as is rather common in the art, but with a width and depth of the insert section 41 exceeding the width and depth of the cross section of the first insert sections 21. For example the width and depth of the second insert section may be 4x4, 5x5, 6x6 meters, etc.

The lattice insert sections 41 are each composed of four longitudinally extending corner chords that are spaced from one another and are each parallel to the longitudinal axis of the insert section 41. Each of said corner chords is arranged at a corner of the square crosssection of the insert section 41 a perpendicular to said longitudinal axis so that each pair or adjacent corner chords defines a side plane or the insert section 41.

Each corner chord is provided along the length with joint members. Each insert section 41 is further composed of elongated rigid bracing members, both diagonal bracing members and transverse bracing members (so at an incline to the chords and perpendicular to the chords). These elongated rigid bracing members extend into the side planes or the insert section 41.

Each elongated rigid bracing member of the insert sections 41 has one end connected to a joint member on one corner chord and has another end connected to a joint member on the other corner chord or said pair of corner chords.

As is common in the field, in parallel axial end faces or each insert section 41, axial ends of the four corner chords are provided with connector members, which connector members are adapted to interconnect said insert section 41 to adjoining insert sections 41 or to one or the transition sections 42, 44 or the back mast system.

-20These large cross-section second insert sections 41 are each modular as each connection or an end or an elongated rigid bracing member to a joint member on a corner chord or the second insert section 41 is effected by a releasable fastener allowing for a disassembled transport fashion of the second insert sections 41 in the second insert sections have been disassembled into individual corner chords and individual elongated rigid bracing members. In a preferred embodiment the releasable fastener is a fastener pin that is insertable through aligned holes in the joint member and the end of the elongated rigid bracing member.

So, the multiple second insert sections 41 of the back mast system each have a second cross-sectional size that is significantly greater than the first cross-sectional size or each of the first insert sections 21 or the back mast system. Each second insert section 41 has a third moment of inertia in the back mast pivot plane that is greater than said first moment of inertia in the back mast pivot plane of the first insert sections 21 and a fourth moment of inertia in a plane through said longitudinal axis and perpendicular to said back mast pivot plane that is greater than the second moment of inertia of the first insert sections 21 in a plane through said longitudinal axis and perpendicular to said back mast pivot plane.

Due to the open centered structure of the second insert sections 41, with corner chords and bracing members all located in the side planes and corners and with a simple, relatively lightweight, and easily assembled and disassembled design, an optimized load handling capacity of the back mast 20 and thus of the crane 1 can be achieved with a single beach or second insert sections 41 in the back mast.

In another configuration of the back mast 20, the entire region between the top section 23 and lower section 22 is made up by a single beach or second insert sections 41 with provision of the mentioned lattice transition sections 42, 44 at the lower and upper end of said single strand of sections 41.

The lattice transition sections 42, 44 or the back mast system each include a longitudinal axis. In these sections 42, 44 the four corner chords extend non-parallel to this longitudinal axis as the general shape formed by side planes of the section 42, 44 resembles a truncated pyramid. Each transition section 42, 44 has a first axial end face after a cross-section perpendicular to the longitudinal axis that is agreed to the first cross-sectional size of the first insert sections 21 and is provided, at said first axial end face, with connector members at axial ends of the chords of the transition section so as to allow for connection to one of said first insert sections 21. Each transition section 42, 44 further has a second axial end face

-21thereof a cross-section perpendicular to the longitudinal axis that conforms to the second cross-sectional size of the second insert sections 41 and is provided, said second axial end face, with connector members at axial ends of the chords of the transition section so as to allow for connection to one or said second insert sections 41.

Claims (5)

CONCLUSIONS A multi-configuration crane system comprising: - a crane base (2) with a main mast pivoting structure (2a) adapted to attach to it a main mast (10) of the crane (1) and which provides a horizontal main mast pivoting axis for the main mast relative to the crane base, - a main mast system adapted to provide a plurality of main mast configurations, the main mast system comprising: - a lower main mast section (12) with a first end (12a) connectable to the main mast pivoting structure of the crane base (2) to allow leering of the main mast in a luffing surface, and a second end opposite the first end, - an upper main mast section (13) adapted to cause a load to depend on the main mast, e.g. comprises an assembly of one or more discs (13a) for one or more cables (7) driven by a winch on which the load is suspended, - a plurality of lattice insert sections adapted to be inserted as a single strand of a plurality of the lattice insert sections in the main boom, the lattice insert sections each comprising a longitudinal axis, and wherein the lattice insert sections are each composed of longitudinally extending corner beams are spaced apart and are parallel to the longitudinal axis of the insert section, each of the corner beams being arranged at an angle of a cross section of the insert section perpendicular to the longitudinal axis so that each pair of adjacent corner beams are a side face of the insert section defines, wherein each corner bar is provided along its length with connecting elements, and wherein the insert section is further composed of elongated rigid reinforcement elements, the elongated rigid reinforcement elements extending in the side faces of the insert section, each elongated rigid reinforcement element being an end nde has thereof connected to a connecting element on a corner beam and has another end thereof connected to a connecting element on the other corner beam of the pair of corner beams, wherein - in parallel axial end faces of each insert section - axial ends of the corner beams are provided of connector elements, wherein the connector elements are adapted to connect the insert section to adjacent sections of the main boom, the multiple lattice insert sections comprising: - a set of a plurality of first insertion sections (11), each of which has a first cross-sectional size providing a first moment of inertia in the face plane and a second moment of inertia in a plane through the longitudinal axis and perpendicular to the face plane, - a set of a plurality of second insertion sections (31), each of which has a second cross-sectional size that is greater than the first cross-sectional size of the first insertion sections and which provides a third moment of inertia in the face that is greater than the first moment of inertia in the face and that of a fourth moment of inertia provided in a plane through the longitudinal axis and perpendicular to the luffing surface that is greater than the second moment of inertia in a plane through the longitudinal axis and perpendicular to the luffing surface, wherein, at least the second insert sections (31) are modular in that each connection of an end of an elongated rigid reinforcement element (36) to a connecting element on a corner bar (35) of the second insert section is carried out by a releasable fastener allowing a dismantled transport mode of the second insert sections with the second insert sections disassembled into separate corner bars (35) and individual elongated s rigid reinforcement elements (36), wherein for example the releasable fastening means is a fastening pin that can be inserted through aligned holes in the connecting element and the end of the elongated rigid reinforcing element, - a plurality of lattice transition sections (32, 34), each comprising a longitudinal axis and comprising corner beams extending non-parallel to the longitudinal axis, wherein each transition section at a first axial end face thereof has a cross-section perpendicular to the longitudinal axis corresponding having the first cross-sectional size and being provided, at the first axial end face, with connector elements at axial ends of the beams of the transition section to allow a connection to one of the first insert sections, and each transition section further at a second axial end face has a cross-section thereof perpendicular to the longitudinal axis corresponding to the second cross-sectional size, and is provided, at the second axial end face, with connector elements at axial ends of the beams of the transition section to allow connection to one of the second insert sections , wherein the main mast system is a first configuration of the crane providing: - the main mast (10) is composed of the lower main mast section (12), the upper main mast section (13) and a strand of a plurality of first insert sections (11) between the lower and upper main mast sections, and wherein the main mast system provides a second configuration of the crane in which: - the main mast is composed of the lower main mast section (12), the upper main mast section (13) and a single lower strand of a plurality of second insert sections (31) and a single upper strand of a plurality of first insert sections (11), one of the lattice transition sections (34) is mounted between the upper and lower strands, and wherein another of the lattice transition sections (32) is mounted at a lower end of the lower strand connection, the lower strand to the lower main mast section or, optionally, to a first insert section (11) between the half-timbered transition section and the lower main mast section. The multi-configuration crane system according to claim 1, wherein the crane system further provides a rear mast (20) of the crane on which a ballast load (4) is suspended during a hoisting task, the crane system further comprising: - a rear mast system adapted to provide a plurality of rear mast configurations, the rear mast system comprising: - a lower rear mast section (22) with a first end (22a) connectable to a rear mast pivoting structure (2b) of the crane base (2) to allow for changing the angle of the rear mast into a rear mast pivoting surface, and a second end opposite the first end, - an upper rear mast section (23) adapted to cause a ballast load to depend on the rear mast, which e.g. comprises an assembly of one or more discs for one or more cables driven by a winch on which the ballast load is suspended, a plurality of lattice insert sections adapted to be inserted as a single strand of a plurality of the lattice insert sections in the rear mast, the lattice insert sections each comprising a longitudinal axis, and wherein the lattice insert sections are each composed of longitudinally extending corner beams are spaced apart and are parallel to the longitudinal axis of the insert section, each of the corner beams being arranged at an angle of a cross section of the insert section perpendicular to the longitudinal axis so that each pair of adjacent corner beams are a side face of the insert section defines, wherein each corner bar is provided along its length with connecting elements, and wherein the insert section is further composed of elongated rigid reinforcement elements, wherein the elongated rigid reinforcement elements extend into the side faces of the insert section, each elongated rigid reinforcement element being an end has one of these connected to a connecting element on a corner bar and has another end thereof connected to a connecting element on the other corner bar of the pair of corner beams, wherein - in parallel axial end faces of each insert section - axial ends of the corner beams are provided of connector elements, wherein the connector elements are adapted to connect the insert section to adjacent sections of the rear mast, the plurality of lattice insert sections comprising: - a set of a plurality of first insert sections (21), each having a first cross-sectional size that provides a first moment of inertia in the rear-mast pivoting surface and a second moment of inertia in a plane through the longitudinal axis and perpendicular to the rear-mast pivoting surface, - a set of a plurality of second insertion sections (41), each of which has a second cross-sectional size that is greater than the first cross-sectional size of the first insertion sections (21) and which provides a third moment of inertia in the surface that is larger than the first moment of inertia in the rear-mast pivoting plane and that of a fourth moment of inertia provided in a plane through the longitudinal axis and perpendicular to the rear-mast pivoting plane that is greater than the second moment of inertia in a plane through the longitudinal axis and perpendicular to the rear-mast pivoting plane, wherein, at at least the second insertion sections (41) are modular in that each connection of an end of an elongated rigid reinforcement element (46) to a connecting element on a corner bar (45) of the second insertion section is carried out by a releasable fastening means whereby a dismantled transport mode of the second insertion sections it is possible for the second insert sections to be dismantled in separate rich corner bars and individual elongated rigid reinforcement elements, wherein, for example, the releasable fastener is a fastening pin that can be inserted through aligned holes in the connecting element and the end of the elongated rigid reinforcement element, - a plurality of lattice transition sections (42, 44), each of which comprises a longitudinal axis and which comprises corner beams extending non-parallel to the longitudinal axis, wherein each transition section at a first axial end face thereof has a cross-section perpendicular to the longitudinal axis corresponding having the first cross-sectional size and being provided, at the first axial end face, with connector elements at axial ends of the beams of the transition section to allow a connection to one of the first insert sections, and each transition section further at a second axial end face thereof has a cross-section perpendicular to the longitudinal axis corresponding to the second cross-sectional size, and is provided, at the second axial end face, with connector elements at axial ends of the beams of the transition section to allow connection to one of the second insert sections , -26 wherein the rear mast system provides a first configuration of the crane in which: - the rear mast is composed of the lower rear mast section (22), the upper rear mast section (23) and a single strand of a plurality of first insert sections (21) between the lower and upper rear mast sections, and wherein the rear mast system provides a second configuration of the crane in which: - the rear mast is composed of the lower rear mast section (22), the upper rear mast section (23) and a single strand of several second insert sections (41) and a single first insert sections (21) or a single strand of several first insert sections (21), wherein one of the lattice transition sections is mounted on one end of the single strand of a plurality of second insert sections (41) and wherein another of the lattice transition sections is mounted on the other end of the single strand. 3. Multi-configuration crane system comprising: - a crane base with a main mast pivoting structure which is adapted to attach a main mast of the crane thereto and which provides a horizontal main mast pivoting axis for the main mast relative to the crane base, - a main mast (10), for example, comprising: - a lower main mast section (12) with a first end connectable to the main mast pivoting structure of the crane base to allow leering of the main mast in a luffing surface, and a second end opposite the first end, - an upper main mast section (13) adapted to cause a load to depend on the main mast, e.g. comprises an assembly of one or more discs for one or more cables driven by a winch from which the load is suspended, - a plurality of half-timbered insert sections (21) adapted to be inserted as a single strand or a plurality of parallel strands of a plurality of the half-timbered insert sections in the main boom, - a rear mast system to form a rear mast (20) to suspend a ballast load (4) during a hoisting task, the crane system being adapted to provide a plurality of rear mast configurations, the rear mast system comprising: - a lower rear mast section (22) with a first end connectable to a rear mast pivoting structure of the crane base to allow for changing the angle of the rear mast into a rear mast pivoting surface, and a second end opposite the first end, - an upper rear mast section (23) adapted to cause a ballast load to depend on the rear mast, - a plurality of lattice insert sections adapted to be inserted as a single strand of a plurality of the lattice insert sections in the rear mast, the lattice insert sections each comprising a longitudinal axis, and wherein the lattice insert sections are each composed of longitudinally extending corner beams are spaced apart and are parallel to the longitudinal axis of the insert section, each of the corner beams being arranged at an angle of a cross section of the insert section perpendicular to the longitudinal axis so that each pair of adjacent corner beams are a side face of the insert section defines, wherein each corner bar is provided along its length with connecting elements, and wherein the insert section is further composed of elongated rigid reinforcement elements, wherein the elongated rigid reinforcement elements extend into the side faces of the insert section, each elongated rigid reinforcement element being an end has one of these connected to a connecting element on a corner bar and has another end thereof connected to a connecting element on the other corner bar of the pair of corner beams, wherein - in parallel axial end faces of each insert section - axial ends of the corner beams are provided of connector elements, wherein the connector elements are adapted to connect the insert section to adjacent sections of the rear mast, the plurality of lattice insert sections comprising: - a set of a plurality of first insert sections (21), each having a first cross-sectional size that provides a first moment of inertia in the rear-mast pivoting surface and a second moment of inertia in a plane through the longitudinal axis and perpendicular to the rear-mast pivoting surface, - a set of a plurality of second insertion sections (41), each of which has a second cross-sectional size that is greater than the first cross-sectional size of the first insertion sections and which provides a third moment of inertia in the face that is greater than the first moment of inertia in the plane rear mast pivoting plane and that of a fourth moment of inertia provided in a plane through the longitudinal axis and perpendicular to the rear mast pivoting plane that is greater than the second moment of inertia in a plane through the longitudinal axis and perpendicular to the rear mast pivoting plane, wherein, at least the second insert sections (41) are modular in that each connection of an end of an elongated rigid reinforcing element to a connecting element on a corner bar of the second insert section is carried out by a releasable fastening means, resulting in a disassembled transport mode 28 of the second insert sections is possible wherein the second insert sections are disassembled into separate corner beams and separate elongated rigid reinforcement elements, wherein, for example, the releasable securing means is a securing pin that can be inserted through aligned holes in the connecting element and the end of the elongated rigid reinforcement element, - a plurality of lattice transition sections (42, 44), each of which comprises a longitudinal axis and which comprises corner beams extending non-parallel to the longitudinal axis, wherein each transition section at a first axial end face thereof has a cross-section perpendicular to the longitudinal axis corresponding having the first cross-sectional size and being provided, at the first axial end face, with connector elements at axial ends of the beams of the transition section to allow a connection to one of the first insert sections, and each transition section further at a second axial end face thereof has a cross-section perpendicular to the longitudinal axis corresponding to the second cross-sectional size, and is provided, at the second axial end face, with connector elements at axial ends of the beams of the transition section to allow connection to one of the second insert sections , wherein the rear mast system is a first configuration of the crane providing: - the rear mast is composed of the lower rear mast section (22), the upper rear mast section (23) and a single strand of a plurality of first insert sections (21) between the lower and upper rear mast sections, and wherein the rear mast system provides a second configuration of the crane in which: - the rear mast is composed of the lower rear mast section (22), the upper rear mast section (23) and a single strand of several second insert sections (41) and a single first insert sections (21) or a single strand of several first insert sections (21), wherein one of the lattice transition sections is mounted on one end of the single strand of a plurality of second insert sections (41) and wherein another of the lattice transition sections is mounted on the other end of the single strand. Method for successively performing a series of hoisting tasks, wherein use is made of a crane system according to claim 1, and wherein one or more of the hoisting tasks are carried out with the main mast in the first configuration and one or more of the hoisting tasks are carried out with the main mast in the second configuration. Method for successively performing a series of hoisting tasks, wherein use is made of a crane system according to claim 2 or 3, and wherein one or more of the hoisting tasks are performed with the rear mast in the first configuration and one or more of said hoisting tasks are executed with the rear mast in the second configuration. 1/2