Crane boom segment for assembly of a crane boom, method for assembling a crane boom

Abstract

A Crane boom segment is provided for assembly of a crane boom by interconnection of multiple crane boom segments from a transport configuration to an operational configuration. The crane boom segment includes a first and second planar latticed truss, each with two chords between which permanent lacing elements extend. Both chords of each planar latticed truss include segment connection parts at their head ends allowing crane boom segments to be connected to each other in series, and in the operational configuration the first and second planar latticed trusses are provided at opposite sides of the longitudinal axis of the crane boom segment. A crane boom segment further includes a first and second lattice web, each lattice web connectable to one of the chords of the first planar latticed truss and one of the chords of the second planar latticed truss. A modular crane includes a travelling base frame which allows for travel of said crane over a surface, and a crane boom assembled from crane boom segments, one end of the crane boom being hingedly connected about a substantially horizontal pivot axis to said travelling base frame.

Claims

1. A crane boom segment for assembly of a crane boom by interconnection of multiple crane boom segments from a transport configuration to an operational configuration, wherein the crane boom segment has a substantially rectangular cross section and a longitudinal axis, the crane boom segment comprising: a first and second planar latticed truss, each with two chords between which permanent lacing elements extend, wherein both chords of each planar latticed truss comprise segment connection parts at head ends thereof, allowing crane boom segments to be connected to each other in series, and wherein in the operational configuration the first and second planar latticed trusses are provided at opposite sides of the longitudinal axis of the crane boom segment; and a first and second lattice web, each lattice web connectable to one of the chords of the first planar latticed truss and one of the chords of the second planar latticed truss, wherein the first and second lattice webs are accordion-type lattice webs, each composed of multiple straight elements that are pivotably interconnected in series by hinges each having a pivot axis, wherein in the folded transport configuration the straight elements are essentially parallel to each other, and in the operational configuration the interconnected straight elements have been pivoted open to form V-shaped pairs of straight elements, wherein the hinges each comprise a fastener member and the chords are provided with complementary fastener members to allow the accordion-type lattice web in the operational configuration connected to the chords, wherein the chords of a planar latticed truss are each provided with one of said complementary fastener members at ends thereof, and with multiple intermediate complementary fastener members between said end complementary fastener members, all intermediate complementary fastener members and one of the end complementary fastener members having the same mutual distance, and the distance between the other end complementary fastener member and an adjacent intermediate complementary fastener member being half that distance, and wherein at the end of a planar lattice truss one chord ends with the mutual distance between the end complementary fastener member and the adjacent intermediate complementary fastener member being half that distance, and the other chord ends with the mutual distance between the end complementary fastener member and the adjacent intermediate complementary fastener member being the distance.

2. The crane boom segment according to claim 1, wherein the hinges prohibit the straight elements from pivoting open further than in the operational configuration.

3. The crane boom segment according to claim 1, wherein the first and second planar lattice webs comprise straight elements of increasing length to provide a crane boom segment which tapers out in the operational configuration.

4. A modular crane, comprising: a travelling base frame which allows for travel of said crane over a surface; and a crane boom assembled from crane boom segments according to claim 1, wherein one end of the crane boom is hingedly connected about a substantially horizontal pivot axis to said travelling base frame.

5. A method of constructing a crane boom by interconnecting multiple crane boom segments, each crane boom segment comprising: a first and second planar latticed truss, each with two chords between which permanent lacing elements extend, wherein both chords of each planar latticed truss comprise segment connection parts at head ends thereof, allowing crane boom segments to be connected to each other in series, and wherein in the operational configuration the first and second planar latticed trusses are provided at opposite sides of the longitudinal axis of the crane boom segment; and a first and second lattice web, each lattice web connectable to one of the chords of the first planar latticed truss and one of the chords of the second planar latticed truss, wherein the first and second lattice webs are accordion-type lattice webs, each composed of multiple straight elements that are pivotably interconnected in series by hinges each having a pivot axis, wherein in the folded transport configuration the straight elements are essentially parallel to each other, and in the operational configuration the interconnected straight elements have been pivoted open to form V-shaped pairs of straight elements, wherein the hinges each comprise a fastener member and the chords are provided with complementary fastener members to allow the accordion-type lattice web in the operational configuration connected to the chords, and allow the accordion-type lattice web in the transport configuration to be disconnected from the chords, wherein the chords of a planar latticed truss are each provided with one of said complementary fastener members at ends thereof, and with multiple intermediate complementary fastener members between said end complementary fastener members, all intermediate complementary fastener members and one of the end complementary fastener members having the same mutual distance, and the distance between the other end complementary fastener member and an adjacent intermediate complementary fastener member being half that distance, wherein at the end of a planar lattice truss one chord ends with the mutual distance between the end complementary fastener member and the adjacent intermediate complementary fastener member being half that distance, and the other chord ends with the mutual distance between the end complementary fastener member and the adjacent intermediate complementary fastener member being the distance, wherein the first and second planar latticed trusses are transportable independently of the collapsed, folded-in accordion-type lattice webs, and wherein the method comprises the steps of: pivoting the interconnected straight elements of both accordion-type lattice webs open from the transport configuration to the operation configuration to form V-shaped pairs of straight elements; connecting the fastener members of the hinges of the accordion-type lattice webs to the complementary fastener members of the chords of the first and second planar latticed trusses to form a crane boom segment; and interconnecting crane boom segments in series by connecting the segment connection parts at the head ends of the chords.

Description

(1) The invention will be further described in relation to the drawings, in which:

(2) FIG. 1. shows an example of a crawler crane made of crane boom segments, possibly according to the first, second and/or third aspect of the present invention;

(3) FIGS. 2a-2c shown different embodiments of a crane boom segment according to a first aspect of the invention;

(4) FIGS. 3a-3b shown an embodiment of a crane boom segment according to a third aspect of the invention;

(5) FIG. 4a shows an embodiment of part of a crane boom segment according to a first aspect of the invention;

(6) FIG. 4b shows an embodiment of a planar latticed truss according to the invention;

(7) FIGS. 5a-5d show an embodiment of a crane boom segment according to a second aspect of the invention;

(8) FIGS. 6a and 6b show an embodiment of a modular crane comprising a crane boom made of crane boom segments, possibly according to the first, second and/or third aspect of the present invention, and further comprising a modular base frame comprising multiple winch base frames according to the fourth aspect of the invention;

(9) FIG. 7 shows an example of a winch base frame according to the fourth aspect of the invention.

(10) In FIG. 1 a crawler crane 1 is shown, designed for lifting loads of several hundred metric tons. The crane 1 as shown is a self-propelled crane and has a travelling base structure 2 which allows for travel of said crane over a surface 9. In many cases said surface will be the ground, possibly reinforced by a suitable foundation, but it is also envisaged that the crane is used on a large pontoon or the like.

(11) A revolving superstructure 3 is mounted on said base structure 2, so that the superstructure 3 can rotate about a vertical revolving axis A with respect to the base structure 2.

(12) The crane 1 further has a boom 4 and a backmast 5. One end 4e of the boom is hinged to the superstructure 3 so that the boom 4 pivots about horizontal pivot axis 6. The backmast 5 is also hinged to the superstructure 3 about a horizontal pivot axis 7. Furthermore a fly jib arrangement 8 is provided, including jib 8a and stay beams 8b, 8c which are all pivotably connected to the top of the boom 4.

(13) Possibly, the boom 4 has an A-frame design, with two elongated boom sections separately connected to the superstructure and merging towards each other near the top of the boom 4. Possibly, the backmast 5 has an inverted Y-frame design with two lower backmast sections pivoted to the superstructure 3 and merging into a single section.

(14) In the shown embodiment of the crane 1 the boom 4, the backmast 5, the jib 8a and stay beams 8b, 8c are composed of segments to allow for easy transport of the entire crane from one construction site to the next. In particular various crane boom segments 4a and backmast segments 5a are indicated. Preferably, some or all of the segments are embodied as crane boom segments according to the present invention.

(15) A main load hoisting device is associated with the boom 4 for hoisting a load. In FIG. 1a hoisting cable 11 is shown, extending between a crane hook 13 and a main load-hoisting winch 12, which in the shown embodiment is mounted on the revolving superstructure 3.

(16) Furthermore, in the embodiment of FIG. 1, a superstructure ballast 15 is provided, here composed of a stack of steel ballast plates. The rear end of the superstructure 3 is adapted for supporting said superstructure ballast 15 thereon.

(17) The crane 1 further has a superlift ballast 16 and an associated connection 17 serving to connect said superlift ballast 16 to the backmast 5 while the superlift ballast 16 is resting on the surface 9 (as in FIG. 1) and/or suspended from said backmast 5 above said surface.

(18) In this crane 1 of FIG. 1 the base structure 2 is designed as crawler assembly comprising tracks. Other designs are also envisaged such as wheeled carriage assemblies (for smaller cranes) or skid arrangements and the like.

(19) In FIGS. 2a-2c the operational configuration of different embodiments of respective crane boom segments 20, 50, 60 according to a first aspect of the invention are shown in its entirety.

(20) Crane boom segment 20 as shown in FIG. 2a will be explained below in detail, the crane boom segments shown in FIGS. 2b and 2c are of essentially the same configuration and will not be explained in detail. All three crane boom segments have a substantially rectangular cross section, are hollow on the inside and comprise a longitudinal axis L. From the drawings it can be discerned that the cross section of crane boom segment 20 as shown in FIG. 2a has a larger height than width, the cross section of crane boom segment 50 is variable as the crane boom segment 50 is tapering, and the cross section of crane boom segment 60 is essentially square.

(21) The components of crane boom segment 20 are shown in detail in FIGS. 4a and 4b, and will be discussed in more detail in relation to these drawings. The crane boom segment 20 of FIG. 2a comprises a first planar latticed truss 21 and second planar latticed truss 22, which in the shown operational configuration are provided at opposite sides of the longitudinal axis L of the crane boom segment. Planar latticed truss 21 is provided with two chords 21a, 21b, between which permanent lacing elements 21c extend, and planar latticed truss 22 is provided with two chords 22a, 22b, between which permanent lacing elements 22c extend. Both chords of each planar latticed truss comprise segment connection parts 26 at their head ends allowing crane boom segments to be connected to each other in series, as will be explained in detail in relation to FIG. 4a. The planar latticed trusses 21 and 22 of this embodiment are embodied identical; such a planar latticed truss 120 is shown in detail in FIG. 4b, and described below in relation to this drawing.

(22) The crane boom segment 20 further comprises a first lattice web 23 and a second lattice web 24. In the shown operational configuration first lattice web 23 is connected to chord 21a of the first planar latticed truss 21 and chord 22a of the second planar latticed truss 22, and second lattice web 24 is connected to chord 21b of the first planar latticed truss 21 and chord 22b of the second planar latticed truss 22.

(23) In FIG. 4a, the crane boom segment is shown not yet in the operational configuration, prior to the connection of the lattice webs 23, 24 to the first planar latticed truss 21.

(24) The first and second lattice webs 23, 24, shown in FIGS. 2a and 4a are embodied according to the first aspect of the invention as accordion-type lattice webs, each composed of multiple straight elements 23a, 24a that are pivotably interconnected in series by hinges 23b, 24b. In FIGS. 2a and 4a the lattice webs 23, 24 are in their operational configuration, wherein the interconnected straight elements 23a, 24a have been pivoted open to form V-shaped pairs of straight elements, forming triangular units. The hinges 23b, 24b each allow the straight elements 23a, 24a to be folded to a transport configuration in which the straight elements 23a, 24a are essentially parallel to each other, according to the first aspect of the invention. Hence, instead of transporting a folded out lattice web, a folded in accordion of parallel straight elements and hinges is to be transported, having a significant smaller volume than the folded out lattice web. This is in particular advantageous when crane boom segments having an increased height for improved strength are desired: the accordion-type lattice web allows the lattice web to have a height exceeding that of a transport container, while still being able to be transported in such a transport container.

(25) In an embodiment, the hinges are configured such that they prohibit the straight elements from pivoting open further than in the operational configuration. This is advantageous during installation: on location, the folded-in accordion-type lattice webs need to be unfolded, and subsequently connected to the chords. In view of the dimensions and weight of the lattice webs this unfolding is in practice frequently carried out by a forklift or the like. It is advantageous to configure the hinges such that they prohibit the straight elements from pivoting open further than in the operational configuration, as a result of which the unfolding operation automatically results in a correct degree of folding out.

(26) As indicated above, the crane boom segment 50 shown in FIG. 2b is tapering. First and second lattice webs 53, 54 of the crane boom segment 50 as shown in FIG. 2b comprise straight elements 53a, 54a of increasing length, seen in the direction in which the crane boom segment tapers out, to provide a crane boom segment which tapers out in the operational configuration. The planar latticed trusses 51, 52 of the shown embodiment are identical to planar latticed trusses 21, 22 of FIG. 2a, and also to the planar latticed trusses 61, 62 of the crane boom segment 60 of FIG. 2c. This is advantageous as this allows the configuration of a crane boom comprising tapered crane boom segments as shown in FIG. 2b, square crane boom segments as shown in FIG. 2c and having a rectangular cross-section as shown in FIG. 2a, all with the same planar latticed trusses. This reduces the number of different components, while maintaining a freedom in design options.

(27) It is not shown, but likewise conceivable that the crane boom segments are tapering in two dimensions, hence, not only the first and second lattice webs being tapering as shown in FIG. 2b, but also the planar latticed trusses being provided tapering.

(28) The hinges 23a, 23b comprise a horizontal pivot axis A, indicated for two hinges in FIG. 4a. Pivot axis A is perpendicular to the longitudinal axis L of the crane boom segment. The hinges comprise a fastener member, 23b, 24b, which are here embodied as a portion of the hinge which is provided with a hole. The chords 21, 22, are provided with complementary fastener members to allow the accordion-type lattice webs 23, 24 to be connected to the chords. The connection between the lattice webs 23, 24 and the chords 21, 22 is achieved here by pins 25a, 25b, 25c, 25d, which are provided fastener members 23b, 24b and the complementary chord fastener members. Because of the connection between the fastener members 23b, 24b of the hinges of the lattice webs and the complementary fastener members on the chords, these individual members cannot be discerned in the operational configuration as shown in FIG. 2a. The complementary chord fastener members are embodied as pin-receiving holes 125 provided in the chord, as shown in FIG. 4b and described in detail below.

(29) In FIG. 4b, a planar latticed truss 120 is shown in detail. Here two chords 121 and 122 can be discerned, which essentially are longitudinal beams formed by parallel interconnected plates 121a, 121b, defining a rectangular cross section. Between the chords 121 and 122, permanent lacing elements 123 extend. The lacing elements are embodied as rods, which are at the ends thereof permanently fixed to the chords. Here, the lacing elements are embodied as circular rods, forming triangular units between the chords 121, 122.

(30) Both chords 121, 122 comprise segment connection parts 124 at their head ends, allowing crane boom segments to be connected to each other in series. In the shown embodiment, the connection parts 124 are embodied as a set of plates 124a, 124b, 124c, 124d, protruding at the head ends in the longitudinal direction of the chords, which are each provided with bores which are provided such that they define a connection axis O, perpendicular to the chords, in the plane of the planar latticed truss. In these bores a connection pin can be received for providing the connection between the crane boom segments. In the shown embodiment, the set of plates 124a, 124b, at one head end of a chord is offset in the direction of the connection axis O, allowing the bores of a crane boom segment to line up with the bores in the set of plates 124c, 124d, of an adjacent crane boom segment to be connected to these.

(31) The planar latticed truss 120 is suitable to be used in a crane boom segment according to the first embodiment of the present invention. To this end, the chords 121, 122 are provided with complementary fastener members 125, allowing fastener members of the hinges of an accordion-type lattice web to be connected to the chords 121, 122.

(32) In the shown embodiment, the complementary fastener members 125 are embodied as pin-receiving holes provided in the plates 121a, 121b of a chord. In the shown embodiment, as is preferred, each of the chords 121, 122 of a planar latticed truss is provided with end complementary fastener members 125e at their ends and with multiple intermediate complementary fastener members 125i between said end complementary fastener members 125e, all intermediate complementary fastener members and one of the end complementary fastener members having the same mutual distance d, and the distance between the other end complementary fastener member and an adjacent intermediate complementary fastener member being half that distance d, and wherein at the end of a planar lattice truss one chord ends with the mutual distance between the end complementary fastener member and the adjacent intermediate complementary fastener member being half that distance d, and the other chord ends with the mutual distance between the end complementary fastener member and the adjacent intermediate complementary fastener member being the distance d. An effect of this configuration of complementary fastener members is that both planar latticed trusses of a crane boom segment can be embodied identically while allowing the connection of identical first and second lattice webs. This reduction of the number of different components of a crane boom segment is highly advantageous on-site during assembly.

(33) In the shown embodiment, the complementary fastener members 125 on a chord are provided at a distance from the portion of the chord from which the permanent lacing elements 123 extend. This is advantageous for the strength of the boom segment.

(34) It is noted here that the planar latticed truss 120 is also suitable to be used in a crane boom segment according to the third embodiment of the present invention. To this end, the chords 121, 122 are provided with mating chord fastener members 125, 126, to connect another planar latticed truss directly onto of the planar latticed truss 120 by providing a connection between the chord fastener members 125, 126.

(35) In the shown embodiment, the members 125 can thus advantageously be used as complementary fastener members 125, allowing fastener members of the hinges of an accordion-type lattice web to be connected to the chords 121, 122, according to the first aspect of the invention, and alternatively, the same members 125 can be used as chord fastener members 125 to connect another planar latticed truss directly onto of the planar latticed truss 120 by providing a connection between the chord fastener members 125, 126.

(36) Mating chord fastener members 126 (according to the third aspect of the invention) are provided as lugs, protruding from the chords 121, 122, opposite to the chord fastener members 125 with respect to the plane of the planar lattice truss 120. Hence, the mating chord fastener members are also provided at the ends of the chords and between the ends, similar to the configuration of the complementary fastener members according to a preferred embodiment of the first aspect of the invention. The lugs 126 comprise an opening which is adapted to align with the pin-receiving holes of the chord fastener members 125 in the operation configuration, when another planar latticed truss is connected directly onto of the planar latticed truss 120, allowing a pin to provide a connection between the mating chord fastener members 125, 126.

(37) The operational configuration of a crane boom segment 40 according to a third aspect of the invention is shown in FIGS. 3a and 3b. This crane boom segment 40 comprises four planar latticed trusses 41, 42, 43, 44, and two lattice webs 45, 46, which are in the shown embodied are configured according to the first aspect of the invention.

(38) Each planar latticed truss is embodied as the planar latticed truss 120 shown in detail in FIG. 4b. In particular, planar latticed truss 41 comprises two chords 41a, 41b between which permanent lacing elements 41c extend, planar latticed truss 42 comprises two chords 42a, 42b between which permanent lacing elements 42c extend, planar latticed truss 43 comprises two chords 43a, 43b between which permanent lacing elements 43c extend and planar latticed truss 44 comprises two chords 44a, 44b between which permanent lacing elements 44c extend. Segment connection parts 41e, 42e, 43e, 44e are provided at their head ends allowing crane boom segments to be connected to each other in series.

(39) Members on the chords 41a, 41b, 44a, 44b, which are similar to members 125 as shown in FIG. 4b are used as complementary fastener members connecting one accordion-type lattice web 45 to the chord 41a of the first planar latticed truss 41 and the chord 42a of the second planar latticed truss 42. The other accordion-type lattice web 46 is connected to the chord 41b of the first planar latticed truss 41 and chord 42b of the second planar latticed truss 42. In particular is the connection between the lattice webs and the chords achieved by pins 47 provided in the chord fastener members, which are embodied as pin-receiving holes 125 provided in the plates of a chord, as shown in FIG. 4b. Because of the connection between the fastener members of the hinges of the lattice webs and the complementary fastener members on the chords, these individual members cannot be discerned in the operation configuration as shown in FIG. 3a.

(40) According to the third aspect of the invention, the crane boom segment comprises a third planar latticed truss 43 and, as is preferred, also a fourth planar latticed truss 44. Each of the chords 41a, 41b of the first planar latticed truss 41 and each of the chords 43a, 43b of the third planar latticed truss 43; and each of the chords 42a, 42b of the second planar latticed truss 42 and each of the chords 44a, 44b of the fourth planar latticed truss 44 are provided with mating chord fastener members 125, 126. In the shown operational configuration the third planar lattice truss 43 is connected directly onto of the first planar latticed truss 41 by providing a connection between the mating chord fastener members. In the shown embodiment, the connection is provided by connection pins 48 provided in the mating chord fastener members, which are embodied as pin-receiving holes 125 provided in the plates of a chord, as shown in FIG. 4b, and mating chord fastener members 126 embodied as lugs, protruding from the chords, as shown in FIG. 4b. Because of the connection between the mating chord fastener members, these individual members cannot be discerned in the operation configuration as shown in FIG. 3a.

(41) In FIG. 3b, the fourth planar latticed truss 44 is provided with an optional cover plate 49, which in the shown embodiment is provided between the chords 44a, 44b of the planar latticed truss 44, onto of the permanent lacing elements, which are consequently no longer visible. The cover plate 49 may e.g. be provided to contribute to the strength of the crane boom segment, or alternatively to add functionality, such as the ability to be able to walk on a crane boom segment.

(42) In FIGS. 5a-5d an embodiment of a crane boom segment 80 according to a second aspect of the invention is shown. In FIG. 5d, the crane boom segment 80 is shown in the transport configuration, while in FIG. 5a the crane boom segment 80 is in the operational configuration, in which it has a substantially rectangular cross section and a longitudinal axis L. In particular, according to this second aspect of the invention, in the operational configuration of FIG. 5a the height of H first and second lattice webs 83, 85 exceeds the width W of first and second planar latticed trusses 81, 82.

(43) The crane boom segment 80 comprises a first planar latticed truss 81 and a second planar latticed truss 82. Each truss comprises two chords 81a, 81b and 82a, 82b, between which permanent lacing elements 81c, 82c extend. All chords 81a, 81b, 82a, 82b comprise segment connection parts 84 at their head ends, allowing crane boom segments to be connected to each other in series. The segment connection parts 84 are embodied similar to the connection parts 124 shown in FIG. 4b, and have already been described in relation to this drawing. In the operational configuration of FIG. 5a, the first and second planar latticed trusses 81, 82 are provided at opposite sides of the longitudinal axis L of the crane boom segment 80.

(44) Crane boom segment 80 further comprises a first and second lattice web 83, 85, which are connected to the chords both in the operational configuration of FIG. 5a and also in the transport configuration of FIG. 5d, and in the configurations therebetween shown in FIGS. 5b and 5c. In particular, first lattice web 83 is connected to the chords 81b, 82b, and second lattice web 85 is connected to the chords 81a, 82a.

(45) According to the second aspect of the present invention, each of the lattice webs 83, 85 is composed of multiple straight rods 83a, 83b, 85a, 85b forming triangular units. Each straight rod is pivotably connected at one end via a chord hinge to a chord about a pivot axis parallel to the chord. In particular, straight rods 83a are pivotably connected at one end 83a via a chord hinge 82b to chord 82b about a pivot axis 82bP; straight rods 83b are pivotably connected at one end 83b via a chord hinge 81b to chord 81b about a pivot axis 81bP; straight rods 85a are pivotably connected at one end 85a via a chord hinge 82a to chord 82a about a pivot axis 82aP; straight rods 85b are pivotably connected at one end 85b via a chord hinge 81a to chord 81a about a pivot axis 81aP.

(46) It is noted that the chord hinge may be embodied such that a single straight rod is connected to it, such as the chord hinges at the end of some of the chords of the embodiment shown in FIG. 5, but alternatively the chord hinges may also be embodied so as to connect two straight rods to the chord, such as the chord hinges provided between the ends of the chords shown in FIGS. 5a-5d.

(47) According to the second aspect of the invention, the other end of the straight rods is pivotably connected to another straight rod via a central hinge about a parallel pivot axis. In particular, straight rods 83a are pivotably connected at the other end 83a via a central hinge 83c to the end 83b of straight rod 83b, about a pivot axis 83cP; straight rods 85a are pivotably connected at the other end 85a via a central hinge 85c to the end 85b of straight rod 85b, about a pivot axis 85cP.
In particular, in the embodiment shown, the central hinges 83d, 85c connect two straight rods connected to the same chord to two other straight rods connected to the other cord.

(48) The central hinges 83c, 85c of the first and second lattice webs are offset, allowing the central hinges of a lattice web to move away from the plane of that lattice web in the operational configuration, to be folded to a transport configuration whereby the straight rods of the first lattice web and the straight rods of the second lattice web nest into each other.

(49) This configuration of the lattice webs 83, 85 allows the lattice web to be foldable from the operational configuration shown in FIG. 5a to the transport configuration of FIG. 5d, via the configurations shown in FIGS. 5b and 5c. Because the central hinges 83c and 85c are offset, the central hinges 83c of the first lattice web 83 are allowed to move away from the plane of the lattice web 83, towards the opposed side of the crane boom segment. In the transport configuration of FIG. 5d, the straight rods 83a, 83b of the first lattice web 83 and the straight rods 85a, 85b of the second lattice web nest into each other. This nesting principle is in particular visible in FIGS. 5b and 5c. In addition, in the shown transport configuration of this embodiment of the invention, the central hinges of one lattice web lie essentially between the chord hinges of the other lattice web. This is in particular visible in FIG. 5d.

(50) In the shown embodiment, as is advantageous, the central hinges 83c, 85c are provided with locking members to be able to lock the lattice webs in the operational configuration. In FIG. 5c, it is visible that in the shown embodiment, the locking members are embodied as bores 83c, 85c, provided in opposed parts of the central hinges 83c, 85c. In FIG. 5a, it is visible that locking pins 86 are provided in the bores 83c, 85c to lock the lattice webs and prevent them from undesired folding to the transport configuration.

(51) In the embodiment shown in FIG. 5a, a fixation member 87 is shown, which is advantageously provided. Fixation member 87 comprises two rods 87a and 87b, the ends of which are connected to the first and second lattice web 83 and 85, in a plane perpendicular to that of the planar latticed trusses 81 and 82, which rods 87a and 87b are connected pivotably to each other via a central fixation hinge 87c about a fixation pivot axis 87P which is parallel to the other pivot axes 81aP, 82aP, 81bP, 82bP and 83cP, and to the chords 81a, 81b, 82a, 82b, wherein the central fixation hinge 87c is provided with fixation members (not shown in detail) to be able to fixate the fixation member 87 in the operational configuration, and accordingly lock the lattice webs in the operational configuration. The fixation members can e.g. comprise holes forming a socket for a fixation pin.

(52) In FIGS. 6a and 6b, an embodiment of a modular crane 90 is shown, comprising a crane boom 91 assembled from crane boom segments, possibly according to the first, second and/or third aspect of the present invention. In FIG. 6b, a detail of the crane 90 is shown in a perspective view.

(53) Modular crane 90 is embodied as a ring lift crane comprising a travelling base frame 95 which allows for travel of said crane 90 over a surface. Travelling may involve a rotation, translation or a combination thereof. In the shown embodiment, the travelling base frame is provided with bogies 95a, adapted to travel over a ring 96 mounted on a floor 97, allowing the base frame 95 to rotate. Alternative configurations allowing the base frame to rotate are also conceivable. Yet alternatively, it is also conceivable that the travelling base is provided with tracks or wheels, allowing the modular crane to travel.

(54) The modular crane comprises a crane boom 91 comprises two elongated boom sections 91a and 91b, each of which is assembled from crane boom segments allowing the modular crane to be transportable. One end 91a, 91bof each boom section is hingedly connected about a substantially horizontal pivot axis 91A, to the travelling base frame 95. The other ends 91a, 91b of the boom sections 91a, 91b merge towards each other near the top of the crane boom 91.

(55) The modular crane further comprises a backmast 92 that is mounted pivotably to said base frame 95 about a horizontal pivot axis 92P. In the shown embodiment, the backmast 92 comprises two elongated backmast sections 92a and 92b, one end of each backmast section being hingedly connected about the pivotat axis 92P to the base frame 95. The other ends 92a and 92b of the backmast sections are connected to each other via a backmast connection section 92c.

(56) The modular crane 90 further comprises ballast 93, here embodied as containers 93a connected via a lattice structure 93b to the upper ends 92a, 92b of the backmast 92.

(57) Furthermore, a main hoisting device 94 is provided, comprising a main hoisting winch 94a, a main hoist wire 94b that is guided over the crane boom via sheaves 94c and a hook 94d, connected to the main hoist wire 94b. Also a luffing device 96 is provided, comprising a luffing winch 96a and a luffing cable 96b, extending between the luffing winch 96a, the backmast 92, in particular sheaves 96c provided at the upper ends of the backmast sections 92a, 92b, and the crane boom 91.

(58) The base frame as shown comprises two parallel main girders 95b to which the crane boom segments 91a, 91b and the backmast sections 92a, 92b are connected, and one or more cross-girders 95c provided therebetween. The girders 95b, 95c are assembled from girder segments. According to a preferred embodiment of the fourth aspect of the invention, one of the cross-girders 95c comprises two hoist winches 94a, mounted within hoist winch frames 94f, visible in FIG. 6b, which are connected to each other in series via connectors 94g.

(59) The hoist winch frame into which a main hoisting winch 94a is mounted is embodied as a shipping container comprising connectors 94g at the corners thereof according to the fourth aspect of the invention. In FIG. 6b, the cross-girder 95c is clearly visible. The cross-girder 95c is composed of four interconnected hoist winch frames 94f, into which four main hoist winches 94a are mounted. The main hoist winch frames 94f are interconnected via connectors 94g, provided at the corners of the main hoist winch frames 94f.

(60) In the shown embodiment, also the luffing winch 96a is mounted within a luffing winch frame 96f, embodied as a shipping container comprising connectors 96g at the corners thereof. In the shown embodiment, the luffing winch frame 96f is connected to the main girders 95b of the base frame. Preferably, the luffing winch frame 96f also forms part of the base frame, being included into the main girders 95b of the base frame.

(61) An example of such a hoist winch frame 100 comprising a main hoist winch 105 is shown in detail in FIG. 7.

(62) In FIG. 7 it is visible that the entire main hoist winch 105 fits into the container 100, in particular, the container 100 forming an exosceleton about the main hoist winch 105. The container 100 is embodied as a rectangular hexahedron shipping container, comprising 8 corners. In the shown embodiment, each of the corners of the container is provided with connectors 101, allowing the hoist winch frame 100 to be connected to the girders of the base frame.

(63) It is noted that due to the significant weight of a main hoist winch, which may be up to 28 tons including the hoist wire, the dimensions of a hoist winch frame may be smaller than other shipping containers. In particular, to be able to connect the hoist winch frame and integrate it into the base frame, the hoist winch frame preferably a cross-sectional dimension H*W that allows the connection to girder segments. On the other hand, the length L of the container 100 may be kept relatively small.

(64) It is conceivable that a hoist winch frame, or multiple hoist winch frames connected to each other in series, together form a girder. Alternatively, the hoist winch frame(s) is/are connected to girder segments to form a girder.