U.S. patent application number 12/664311 was filed with the patent office on 2010-07-01 for segment for a tower, tower constructed from tower segments, element for a segment for a tower, method for the pre-assembly of segments for a tower, method for the assembly of a tower containing segments.
Invention is credited to Valere Croes.
Application Number | 20100162652 12/664311 |
Document ID | / |
Family ID | 38926340 |
Filed Date | 2010-07-01 |
United States Patent
Application |
20100162652 |
Kind Code |
A1 |
Croes; Valere |
July 1, 2010 |
Segment for a Tower, Tower Constructed from Tower Segments, Element
for a segment for a Tower, Method for the Pre-Assembly of segments
for a Tower, Method for the Assembly of a Tower Containing
Segments
Abstract
A segment for a tower containing a number of longitudinal corner
elements (2), with protruding flanges (3a, 3b) at the bottom and
top end, by which the flanges protrude in opposite directions, and
the corner elements being interconnected by cross bars (4), the
bottom flanges being located in a bottom plane (BOT), and the top
flanges in a top plane (TOP), the flanges (3b) at the bottom side
being directed outward, and the flanges at the top (3a) being
directed inward.
Inventors: |
Croes; Valere;
(Nieuwerkerkene, BE) |
Correspondence
Address: |
JANSSON SHUPE & MUNGER LTD.
245 MAIN STREET
RACINE
WI
53403
US
|
Family ID: |
38926340 |
Appl. No.: |
12/664311 |
Filed: |
June 12, 2008 |
PCT Filed: |
June 12, 2008 |
PCT NO: |
PCT/EP08/57402 |
371 Date: |
December 11, 2009 |
Current U.S.
Class: |
52/651.01 ;
52/655.1; 52/745.17 |
Current CPC
Class: |
F05B 2240/9121 20130101;
E04H 12/085 20130101; F03D 13/40 20160501; F03D 13/10 20160501;
F03D 13/20 20160501; Y02E 10/72 20130101; Y02B 10/30 20130101; E04H
12/10 20130101; Y02E 10/728 20130101 |
Class at
Publication: |
52/651.01 ;
52/655.1; 52/745.17 |
International
Class: |
E04H 12/00 20060101
E04H012/00 |
Foreign Application Data
Date |
Code |
Application Number |
Jun 15, 2007 |
BE |
BE 2007/0301 |
Claims
1-14. (canceled)
15. A segment for a tower, the segment comprising a number of
longitudinal corner elements with flanges which protrude sideways
in opposite directions and extend in planes transverse to the
longitudinal direction at bottom and top ends of the corner
elements, the corner elements being interconnected by cross bars,
the bottom flanges being directed outward and located in a bottom
plane transverse to the longitudinal direction, and the top flanges
being directed inward and located in a top plane transverse to the
longitudinal direction.
16. The segment of claim 15 wherein the segment contains 3, 4, 5 or
6 corner elements.
17. The segment of claim 15 wherein the longitudinal corner element
includes cylindrical tubes, with the flanges at both ends, the
flanges protruding sideways by a distance larger than the tube
diameter.
18. The segment of claim 17 wherein the segment contains 3, 4, 5 or
6 corner elements.
19. The segment of claim 17 wherein the corner elements include
stiffener plates between the tube and the flanges.
20. The segment of claim 17 wherein the flanges are attached to the
tube element in a position substantially perpendicular to the
longitudinal tube axis.
21. The segment of claim 20 wherein the corner elements are
equipped with stiffener plates between the tube and the
flanges.
22. A corner element for a segment for a tower, the corner element
comprising flanges extending in planes transverse to the
longitudinal direction at top and bottom ends of the corner
element, the flanges protruding sideways in opposite
directions.
23. The corner element of claim 22 including stiffener plates for
the flanges.
24. The corner element of claim 22 wherein including a cylindrical
tube element, the flanges are attached to the tube element in
positions substantially perpendicular to the longitudinal tube
axis.
25. The corner element of claim 24 wherein the corner element is
equipped with stiffener plates for the flanges.
26. A construction kit for a segment for a tower, the construction
kit comprising: a number of longitudinal corner elements with
flanges which protrude sideways in opposite directions and extend
in planes transverse to the longitudinal direction at bottom and
top ends of the corner elements; and cross bars for the
interconnection of the corner elements.
27. The construction kit of claim 26, wherein the corner elements
and the cross bars are packed and transported in a container.
28. The construction kit of claim 26, wherein the container is one
of a standard forty-feet sea container, an equivalent transport
frame and flat bed trailer.
29. A tower comprising at least two tower segments each including a
number of longitudinal corner elements with flanges which protrude
sideways in opposite directions and extend in planes transverse to
the longitudinal direction, the segments being interconnected by
the segment flanges.
30. A method comprising the steps of: providing a number of tower
segments including a number of corner elements with flanges which
protrude sideways in opposite directions and extend in planes
transverse to the longitudinal direction at bottom and top ends,
the bottom flanges being directed outward and located in a bottom
plane transverse to the longitudinal direction, and the top flanges
being directed inward and located in a top plane transverse to the
longitudinal direction; and pre-assembling a number of segments
with different base section into each other.
31. The method of claim 30 further including the steps of: mounting
the pre-assembled tower segments on top of each other; and
interconnecting the mounted segments by the flanges.
32. The method of claim 31 wherein the corner elements are
interconnected by cross bars.
33. The method of claim 32 wherein each corner element contains
cylindrical tubes, the flanges being at both ends of the tubes and
protruding sideways by a distance larger than the tube
diameter.
34. The method of claim 33 wherein the corner elements include
stiffener plates between the tube and the flanges.
Description
[0001] The invention relates to a segment for a tower.
[0002] Additionally, the invention relates to an element for a
segment for a tower.
[0003] Furthermore, the invention relates to a building package for
a segment for a tower.
[0004] Additionally, the invention relates to a working method for
the assembly of multiple segments for a tower.
[0005] The invention further relates to a method for the
construction of a tower, containing segments.
[0006] The invention further relates to a tower constructed from
tower segments.
[0007] Towers containing segments are, amongst other applications,
used for wind turbine constructions.
[0008] Known and so called tubular towers are constructed from a
number, usually made from steel or concrete, tower elements in
tubular form.
[0009] Each element is a tubular segment, of which the section
reduces towards the tower top.
[0010] Each of these tubular segments is manufactured
separately.
[0011] At the building site, the separate tubular tower sections
are mounted on top of each other.
[0012] The major disadvantage of this construction method is that
these tower elements are very large and heavy, requiring also very
heavy handling equipment to manufacture, transport and mount the
tower segments.
[0013] For many locations, it is very difficult or even impossible
because, for instance, the roads towards the construction site are
not adapted for this heavy equipment, or the terrain cannot support
the heavy equipment, or due to lack of sufficient space for the
equipment that is required to mount the tower parts.
[0014] Additionally, in many countries the required heavy handling
equipment is not available, or rare and expensive.
[0015] Even if the equipment is readily available, the
transportation of the tubular tower sections requires oversized
transportation convoys, with related consequences such as temporary
road and highway blocks.
[0016] Therefore, for many applications, this conventional tubular
tower is not or less desirable.
[0017] It is a major aim of the current invention to provide an
economically attractive tower segment, to at least reduce or avoid
the described disadvantages of the conventional technology.
[0018] For that purpose, a segment of the tower is characterized by
a number of longitudinal corner elements, with flanges at both ends
extending in planes transverse to the longitudinal direction and
protruding sideways in opposite directions, the corner elements
being mutually connected by cross bars, the flanges at the bottom
being situated in a bottom plane transverse to the longitudinal
direction, and the top flanges being situated in a top plane
transverse to the longitudinal direction, the bottom flanges being
orientated outward, and the top flanges inward.
[0019] The corner elements constitute the ribs of each tower
segment, the flanges at the top providing a connection point for
the next tower segment that is mounted on top.
[0020] This construction method allows a stepwise reduction of the
segment section, while in principle the same basic elements (corner
elements and cross connection plates) can be reused.
[0021] The concept allows a tower construction that requires much
less and lighter production and handling equipment.
[0022] On locations where conventional tubular towers would be
difficult, or impossible to install, the tower concept, according
to the current invention, could be installed.
[0023] It has to be recognized that towers, made from a collection
of different bars and beams, are a known technology. Known examples
are tower for electric high voltage overhead lines (so called
classic lattice towers).
[0024] Such lattice towers however, are constructed out of a very
large number of members. Both the manufacturing and assembly of
such lattice towers is very labor intensive, and requires
technically skilled personnel. Furthermore, the amount of bolted
connections, to be made on site, is extensive and also depending on
the tower size (base section size and tower height).
[0025] The assembly of such towers requires skilled and experienced
technicians, and is therefore costly, especially in countries where
the expertise is not available, and the required specialists have
to be provided from abroad.
[0026] Prior art elements have been provided with flanges at
opposite ends of longitudinal members to connect elements to each
other, as for instance known from U.S. Pat. No. 4,187,034 and U.S.
Pat. No. 5,687,537. Said document disclose elements with flanges at
both ends. The shape and form of the flanges is such that when
connected to each the longitudinal axes of the elements coincide,
i.e. the two elements extend along a single line. The sideways
protrusion to opposite sides of the flange in the present invention
allows a sideways shift between two elements.
[0027] The tower segments, according to the invention, allow much
easier working methods and a higher degree of automation, in a
sense of reducing the required number of basic operations.
[0028] The segments for a tower, according to the current
invention, require much less different elements, and therefore
easier assembly methods, on site, or partially pre-assembled in the
factory.
[0029] Additionally, the concept allows the composition of building
packages, suitable for tower segments of different base section,
while the length of each segment can and preferably should be the
same (for instance 12 m standard length for commercial steel
tubing).
[0030] A large amount of simplification in the assembly process of
the tower segments, as well as automation of the handling is made
possible this way. The required knowledge, as well as the required
training, of the personnel doing the assembly of such tower
segments, is greatly reduced.
[0031] Preferably the corner elements are symmetric in profile.
Even more preferable, these profiles are cylindrical tubes,
equipped with flanges at both sites, the flanges sideways
protruding by a distance larger than the diameter of the corner
profile.
[0032] The next tower segment can then be mounted on top and
connected to the flanges of the tower segment below, which
simplifies the stacking of the subsequent tower segments.
[0033] The essence of the eccentrically placed flanges, is situated
in the fact that, this way, a gradual decrease in base section is
obtained, while the number and section of the corner elements
remains the same, and only the dimension of the cross connection
plates has to be adapted.
[0034] This provides an elegant and simple way to adapt the
resistance of the tower structure to the decreasing loading in
function of height.
[0035] This way it is possible to maintain the same stress level,
regardless of the tower segment in which the tube is
incorporated.
[0036] Preferably, the end flanges are equipped with reinforcement
stiffeners. These stiffeners reinforce the support capacity of the
flanges.
[0037] Preferably, the flanges are perpendicular to the
longitudinal axis of the corner elements.
[0038] Although, in the most general sense of the invention, this
flange can have an angle other than 90.degree., the angle is
preferably perpendicular.
[0039] When the angle is not perpendicular, the tower segments
become tapered, and therefore less attractive with regard to
simplicity.
[0040] The highest level of simplicity, with regard to construction
and assembly is obtained when the flanges are attached to the
corner elements, at a straight angle.
[0041] In the proposed design, each tower segment has 4 corner
elements. This number is preferable from a structural point of
view, however, the concept remains equally valid for a different
quantity (3, 5, 6, . . . ).
[0042] The element for a segment, according to the invention, is
characterized by having flanges at both ends that are protruding
sideways in opposite directions and in planes transverse to the
longitudinal direction. Preferably, the elements are equipped with
reinforcement stiffeners at the flanges.
[0043] The construction package, for a segment for a tower,
contains a number of longitudinal corner elements, having
protruding flanges at the top and bottom end, the flanges being
orientated in opposite directions, and cross connection plates for
the mutual connection of the corner elements.
[0044] The cross bars are present for the lateral connection
between the corner elements.
[0045] The method for the assembly of tower segments, according to
the invention, is characterized by separate tower segments being
pre-assembled in vertical position and segments of different base
section that are assembled into each other.
[0046] The possibility to pre-assemble segments into each other
offers considerable advantages with regard to space savings on site
and manipulation cost.
[0047] A considerable advantage of the invention is the large
amount of automation that can be achieved in the fabrication and
assembly processes, as a consequence of the concept.
[0048] A tower segment can be assembled, and the next larger
segment (with larger base section) around the first one, and again
the next larger segment around the second one, and so on.
[0049] In order to fit into each other, and to be easily
retrievable afterwards, odd and even numbered tower segments can be
pre-assembled in two separate stacks.
[0050] Odd en even numbered tower segments, with different base
sections, fit into each other.
[0051] Next, the largest tower segment is mounted on the
foundation, followed by subsequent smaller tower segments.
[0052] The invention makes it possible to mount towers at locations
with limited available space.
[0053] These and other aspects of the invention are described and
demonstrated in the following drawings.
[0054] In the drawings is illustrated:
[0055] FIG. 1: A known tower concept for wind turbines, containing
conventional cylindrical tube elements.
[0056] FIG. 2: A known classic lattice tower concept for wind
turbines.
[0057] FIGS. 2A and 2B: known elements for towers.
[0058] FIG. 3: A tower concept, with segments, according to the
invention.
[0059] FIG. 4: A corner element, for a segment, for a tower,
according to the invention.
[0060] FIG. 5: A construction kit, for a segment, for a tower.
[0061] FIG. 6: The assembly of a tower segment.
[0062] FIG. 7: The assembly of different tower segments.
[0063] FIGS. 8, 9 and 10: The stacking of subsequent tower
segments.
[0064] FIG. 11: A segment, in top view, according to the
invention.
[0065] FIGS. 12 and 13: Assembly of a tower, according to the
invention.
[0066] The figures are not always drawn to scale, and similar
elements are in principle referred to with similar identification
numbers.
[0067] Dimensions, indicated on the figures, are given by means of
example, and should not be considered as constraints, unless
explicitly specified otherwise.
[0068] FIG. 1 shows, in front, side and top view, a wind turbine
with, in this example, a tower made of three conventional tubular
segments. Some dimensions are specified in this figure, as not
limitative example.
[0069] Such segmented tower concepts for wind turbines are
manufactured as follows: [0070] The tubular tower segments are
fabricated in the factory. [0071] Each of these tubular tower
segments is transported to the building site, by means of special
over size transportation convoy, because of the large size of these
elements. [0072] On site, the segments are mounted on top of each
other.
[0073] Next, the nacelle of the wind turbine is mounted on the
tower top, and finally the blades are mounted on the rotor hub.
[0074] A major disadvantage of this construction method is that the
elements of the tower are considerably large and heavy, requiring
very heavy equipment to fabricate, transport and assemble these
elements.
[0075] For many locations, this is not possible because, for
instance, the roads leading to the building site are not adapted to
the requirements to transport these elements, or the soil bearing
capacity being insufficient to carry the equipment and the load, or
due to lack of free space at the building location.
[0076] In many countries, the required handling and transportation
equipment is not present, or not readily available and
expensive.
[0077] FIG. 2 illustrates a tower, for a wind turbine, made of a
large number of interconnected elements (classic lattice
construction). This construction has the disadvantage that the
assembly is very complex, due the large amount of elements, and
requires specialized personnel.
[0078] Hundreds of bolted connections have to be made on site.
[0079] FIG. 2A illustrates a known construction of elements,
disclosed in U.S. Pat. No. 4,187,034.
[0080] The elements are provided with flanges at both ends, the
flanges do not protrude sideways, but along the longitudinal
direction of the elements. When the flanges are interconnected the
two elements extend along the same line.
[0081] FIG. 2B illustrates another known construction of
longitudinal elements.
[0082] In this construction flanges are provides at both ends.
Although the flanges extend in planes transverse to the
longitudinal direction, they do not protrude sideways in opposite
directions. Both flanges form a circle with the centre point
coinciding with the longitudinal axis of the elements. When the
flanges are interconnected, the longitudinal axes of the two
elements coincide. The two elements also have different ends.
[0083] FIG. 3 illustrates a tower according to the invention. The
tower is constructed from segments (1).
[0084] The segments contain a number of corner elements (2), in
this example four corner elements (2).
[0085] The corner elements (2) are foreseen of flanges (3a) and
(3b) at, respectively, the top and bottom end.
[0086] The cross bars (4) provide interconnections between the
corner elements.
[0087] FIG. 4 shows a corner element (2). View (A) is a side view,
view (B) a front view, and view (C) a top view and side view, in
which is shown how two flanges are connected together, in this
example by means of bolts (7).
[0088] Dimensions, indicated on the figures, are given by means of
example, and should not be considered as constraints, unless
explicitly specified otherwise.
[0089] However, the specified dimensions can be considered to be
realistic approximations, corresponding with the order of magnitude
of the construction.
[0090] In this example, the length of the corner elements is 12
meter, which is a practical, commercially available size, and an
ideal size for transportation in 40 feet sea containers.
[0091] Preferably, the length of the corner elements is situated
between 6 and 16 meter.
[0092] Longer corner elements are, due to their length and weight,
difficult to handle and transport, while for shorter elements, the
required number of tower segments, for a tower with conventional
height, becomes so large that the assembly becomes more labor
intensive, such that the advantage of the invention becomes less
obvious.
[0093] The corner element (2) contains flanges (3a) and (3b),
protruding sideways in opposite directions.
[0094] Additionally, the corner element is equipped with stiffeners
(5). The stiffeners (5) support and reinforce the flanges.
[0095] View (C) demonstrates how the flanges of subsequent corner
elements are interconnected and how two corner elements are stacked
on top of each other, with an axial offset, which is schematically
shown in the figure, by means of the arrow (8).
[0096] As can be seen by comparison with FIGS. 2A and 2B, wherein
the elements are axially aligned, such an axial offset is not
possible with the known constructions.
[0097] In this example, the corner element is a cylindrical tube,
between the flanges (3a) and (3b).
[0098] This is a preferred construction form. However, the section
between the flanges can possibly have an alternative section, like
a square, T, H or other beam section.
[0099] Preferably, the selected beam should have symmetric strength
properties, relative to the major reference axes (X and Y).
[0100] A round tube is most preferable, because for such a tube,
the symmetry is omni-directional, resulting in an ideal
strength/weight ratio.
[0101] FIG. 5 illustrates how the tower elements can be stacked in
a conventional 40 feet sea container.
[0102] A number of corner tube elements (2) fit exactly inside the
container. The cross connection plates (4) fit in the remaining
free space.
[0103] A standard 40 feet container is the preferred transportation
method; however, the advantages of the concept remain equally valid
for other transportation methods, such as flat bed trucks or
transport frames.
[0104] The tower construction kit can be assembled easily and
loaded onto conventional trucks or inside standard 40 feet sea
containers and transported to the building site.
[0105] The size and shape of the tower elements allow optimal
exploitation of standard container space.
[0106] FIG. 6 illustrates the typical assembly method of a tower
segment MOD, in this case the bottom tower segment.
[0107] The construction kit, inside a container (CT) is delivered,
on site, by means of a conventional truck.
[0108] The corner elements (2) are mounted in vertical position and
mutually connected by means of the cross connection plates (4).
[0109] The distance between the corner elements is determined by
the size of the cross connection plates.
[0110] The flanges (3b) are situated in the bottom plane (BOT) and
directed outward, while the flanges (3a) are situated in the top
plane (TOP) and directed inward.
[0111] FIG. 7 illustrates the assembly of different subsequent
segments, MOD 1, MOD 2, MOD 3 and MOD 4.
[0112] The assembly of the different segments is easy and
straightforward, and in principle, the same for all segments and
the number of elements and required handling operations is
relatively limited.
[0113] FIG. 8 demonstrates the stacking method of different tower
segments. Tower segment MOD 2 is lifted by means of a crane.
[0114] The flanges (3b) of the segment MOD 2 are connected to the
flanges (3a) of the segment MOD 1.
[0115] Next, the tower segment MOD 3 is mounted onto the previous
segment MOD 2, in a similar way.
[0116] This is illustrated in FIG. 9. Next, segment MOD 4 is
mounted onto segment MOD 3, which is illustrated in FIG. 10.
[0117] FIG. 11 shows a tower segment, according to the invention,
in top view. In this example, the segment is equipped with grid
floors (9). These grid floors enable technicians access, to perform
maintenance, connect flanges or carry out safety inspections.
[0118] FIG. 11 also illustrates the natural reduction of the base
section for the subsequent tower segments, due to the stepwise
lateral offset, caused by the inward protrusion of the flanges (3a,
3b).
[0119] As a consequence of this stepwise reduction, the structural
resistance of the subsequent tower sections runs parallel with the
reducing tower load in function of the height.
[0120] Consequently, this results in quasi constant loading of the
corner elements, independent of the tower segment in which they are
incorporated. Due to the quasi constant stress level, the position
of the corner elements in the tower is less relevant, and
consequently the same type of tube (same diameter and wall
thickness) can be applied, resulting in a fabrication process that
can be extensively automated (i.e. application of manipulation and
welding robots).
[0121] This aspect is a major advantage of the invention, compared
to the described conventional tower concepts.
[0122] Due to the natural reduction in tower section, a quasi
constant loading on the cross connection plates can also be
achieved, independent of the tower segment in which they are
incorporated.
[0123] The cross plate section, and the bolt connections (6) with
the corner elements, can consequently be unified.
[0124] Only the planar section of the cross connection plates needs
to be adapted to the corresponding tower segment in which they will
be incorporated.
[0125] For the corner elements, a number of predefined and
preferred connection points (6) can eventually be provided. In
preferable execution forms, and to establish further or complete
standardization of the corner elements, a number of extra
connection points can be provided, although they not necessarily
need to be used in the different tower segments.
[0126] The invention is not restricted to the given examples, but
allows many variations. The shown example is a tower for a 1.8 MW
wind turbine, but the concept can be applied to both smaller and
larger wind turbines as well.
[0127] Examples of possible alternatives are listed below: [0128]
In the shown example, the flanges are perpendicular to the
longitudinal axis of the corner elements.
[0129] However, this angle not necessarily needs to be exactly 90
degrees. Some degree of inclination (i.e. 2-5 degrees) can be
considered as well, resulting in a corresponding taper angle for
the tower segment (reduction of the tower segment section with
increasing height).
[0130] However, such inclination will require a more complicated
production technique.
[0131] In the preferred production method, the flanges will be
welded onto the tube ends, by means of full automatic, submerged,
robot welding equipment. This welding method requires that the
torch is located in a stationary position, on top of the tube, for
the deposition of the inert powder deck, and the deposition of the
weld, while the tube is revolving, with controlled speed, by means
of a rotating manipulator.
[0132] For perpendicular flanges, this procedure is relatively
simple, but more difficult for inclined flanges, although not
impossible. [0133] In the shown methods, the subsequent tower
segments are stacked onto each other, one by one.
[0134] However, a two by two stacking method, or other, is equally
possible as well. [0135] In the shown example, the bottom tower
segment is mounted on a pile foundation that makes use of the same
tube elements as the tower construction. However, the tower concept
is equally valid for mounting on a conventional concrete slab
foundation, or other type of foundation with a top plane situated
at some elevation above ground level. [0136] In the shown examples,
the tower supports a wind turbine. However, the tower concept is
equally valid for other applications such as, electrical overhead
lines, ski lifts, transmission poles, telephone lines, etc . . . .
[0137] In FIG. 7, a method is shown where some tower segments are
pre-assembled next to each other.
[0138] However, the method also allows the pre-assembly of smaller
inside larger tower segments, for example segment MOD 4 inside
segment MOD 2.
[0139] Segments with different base section can be pre-assembled
inside each other, to save space.
[0140] In practice, it is logic to first assemble segment MOD 4,
and next MOD 2 around it.
[0141] A tower of, for instance, 84 meter height, containing 7
tower segments, can be assembled as follows:
[0142] The bottom segment MOD 1 direct on the foundation, and the
remaining odd and even numbered segments inside each other,
preferably on the left and right hand side of the foundation (MOD
1) to minimize the crane distance.
[0143] The possibility to pre-assemble tower segments around
previous segments further provides the possibility to use them as
work platforms for next tower segments.
[0144] The ladders and platforms of previously assembled tower
segments can be beneficially used by the assembly crew to mount
larger tower segments around previous tower segments.
[0145] For the pre-assembly of tower segments, the use of a
relatively small crane is sufficient.
[0146] Only for the final assembly of the tower, and for example a
wind turbine, a larger crane is required.
[0147] The final tower assembly is done by mounting the subsequent
tower segments MOD 2 through MOD 7 in the proper order onto the
base segment MOD 1.
[0148] An advantage of the invention is that the odd end even
numbered tower segments can be pre-assembled in the close vicinity
of the tower foundation. This is especially convenient for building
locations with limited free space.
[0149] A heavy crane is only required during a brief period of
time, and the required action radius is limited, due to the compact
pre-assembly space that is required.
[0150] FIGS. 12 and 13 illustrate the intended working method for
the construction of a tower, and the intended execution form,
according to the invention.
[0151] Odd (MOD 3, MOD 5, MOD 7) and even (MOD 2, MOD 4, MOD 6)
tower segments, having different base sections, but equal length
and similar construction principles, are being pre-assembled in
vertical position, where odd and even numbered segments are stacked
into each other.
[0152] For the pre-assembly of these tower segments, a small size
crane is sufficient (CR).
[0153] Due to their similarity, the pre-assembly process of the
tower segments can be automated to a large degree.
[0154] FIG. 12 illustrates how the building kits are being
delivered on site, for instance in 40 feet sea containers (CT) by
means of trucks (TR).
[0155] The bottom tower segment MOD 1 is mounted or assembled on
the foundation (FN).
[0156] Next, the odd and even numbered tower segments are
pre-assembled inside each other, next to the foundation.
[0157] FIG. 13 shows the result. After all, or at least the
majority, of the tower segments are pre-assembled, a large crane is
used to stack the tower segments onto each other, in the proper
order (see FIG. 10 for example).
[0158] The time that a high and heavy, and thus costly, crane is
required, is considerably less compared to the assembly of classic
lattice towers.
[0159] Otherwise, the masses to be handled, compared to the classic
tubular tower, are also less, also resulting in less lifting
capacity requirements.
* * * * *