U.S. patent application number 14/171956 was filed with the patent office on 2014-10-23 for wind turbine blade holding arrangement.
This patent application is currently assigned to SIEMENS AKTIENGESELLSCHAFT. The applicant listed for this patent is SIEMENS AKTIENGESELLSCHAFT. Invention is credited to KIM LIEBERKNECHT, AAGE MASTRUP, KENNETH HELLIGSOE SVINTH, MAJA ROSE WIELAND.
Application Number | 20140314576 14/171956 |
Document ID | / |
Family ID | 48182759 |
Filed Date | 2014-10-23 |
United States Patent
Application |
20140314576 |
Kind Code |
A1 |
LIEBERKNECHT; KIM ; et
al. |
October 23, 2014 |
WIND TURBINE BLADE HOLDING ARRANGEMENT
Abstract
A wind turbine blade holding arrangement is described comprising
a root frame for securing to a root portion of a blade; an airfoil
clamp for arranging about an airfoil portion of the blade; and an
airfoil frame for supporting the airfoil clamp wherein the root
frame and tip clamp are realized for use in a first blade
orientation in a first storage and transport stage of the blade and
also for use in a second blade orientation in a second storage and
transport stage of the blade, wherein the first and second blade
orientations are essentially at right angles to each other. A
method of handling a number of wind turbine blades is also
described.
Inventors: |
LIEBERKNECHT; KIM; (ARHUS N,
DK) ; MASTRUP; AAGE; (SPJALD, DK) ; SVINTH;
KENNETH HELLIGSOE; (AARHUS C, DK) ; WIELAND; MAJA
ROSE; (BRABRAND, DK) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
SIEMENS AKTIENGESELLSCHAFT |
Munchen |
|
DE |
|
|
Assignee: |
SIEMENS AKTIENGESELLSCHAFT
Munchen
DE
|
Family ID: |
48182759 |
Appl. No.: |
14/171956 |
Filed: |
February 4, 2014 |
Current U.S.
Class: |
416/220R ;
29/889.7 |
Current CPC
Class: |
Y02E 10/72 20130101;
F03D 13/10 20160501; F03D 13/40 20160501; Y10T 29/49336 20150115;
F03D 80/00 20160501 |
Class at
Publication: |
416/220.R ;
29/889.7 |
International
Class: |
F01D 5/32 20060101
F01D005/32 |
Foreign Application Data
Date |
Code |
Application Number |
Apr 23, 2013 |
EP |
13164914.7 |
Claims
1. A wind turbine blade holding arrangement comprising: a root
frame for securing to a root portion of a blade; an airfoil clamp
for arranging about an airfoil portion of the blade; and an airfoil
frame for supporting the airfoil clamp; wherein the root frame and
a tip clamp are realized for use in a first blade orientation in a
first storage and/or transport stage of the blade and also for use
in a second blade orientation in a second storage and/or transport
stage of the blade, wherein the first and second blade orientations
are essentially at right angles to each other.
2. The holding arrangement according to claim 1, wherein the root
frame comprises a number of root end brackets realized for securing
the root frame to the root end of the blade.
3. The holding arrangement according to claim 1, wherein a frame is
realized to be stacked on a further frame of the same type.
4. The holding arrangement according to claim 1, comprising a root
end foot realized to support the root portion of the blade.
5. The holding arrangement according to claim 4, wherein the root
end foot comprises bolt cover portions realized for mounting over
pinbolts of the root end of the blade.
6. The holding arrangement according to claim 4, wherein the root
frame is realized to accommodate the root end foot.
7. The holding arrangement according to claim 1, wherein a frame
comprises a first interface portion for connecting with a second
interface portion of a corresponding frame.
8. A The holding arrangement according to claim 1, comprising a
mounting foot realized for mounting to a surface of a transport
means and/or storage facility.
9. The holding arrangement according to claim 8, wherein the
mounting foot comprises a mounting portion corresponding in shape
to a frame interface portion of a frame.
10. A The holding arrangement according to claim 1, comprising a
connecting strut for connecting adjacent frames.
11. The holding arrangement according to claim 10, wherein a
combined width of a connecting strut and a root frame corresponds
essentially to a width of two airfoil frames.
12. A method of handling a number of wind turbine blades comprising
the steps of: securing a root frame to a root end of a blade;
arranging a tip clamp about an airfoil portion of the blade;
mounting the tip clamp onto a tip frame; arranging the root frame
in a first blade orientation in a first storage and transport stage
of the blade; and arranging the root frame in a second blade
orientation in a second storage and transport stage of the blade;
wherein the first and second blade orientations are essentially at
right angles to each other.
13. The method according to claim 12, comprising the step of
forming a vertical stack of blades comprising a root frame stack
and a tip frame stack.
14. The method according to claim 12, comprising the step of
forming an array of vertical blade stacks.
15. The method according to claim 12, comprising the step of
securing a root end foot to the root end of the blade at an initial
storage and transport stage and removing the root end foot only
after a final storage and transport stage.
Description
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application claims priority to European Application No.
13164914.7, having a filing date of Apr. 23, 2013, the entire
contents of which are hereby incorporated by reference.
FIELD OF TECHNOLOGY
[0002] The invention describes a wind turbine blade holding
arrangement, and a method of handling a number of wind turbine
blades.
BACKGROUND
[0003] Rotor blades for wind turbines can be very long, easily
reaching lengths of 100 meters or more for the larger wind
turbines. The shape of a wind turbine rotor blade is quite complex,
comprising an airfoil portion and also a circular root end portion
for mounting to the hub of the wind turbine. The airfoil portion
usually tapers to a fairly thin tip. It is important to transport
such blades without damage from a factory site to an installation
site, since any surface damage detracts from the blade's
aerodynamic performance and can result in costly repairs. Measures
to protect the blades during handling and transport contribute
significantly to the overall cost of a wind turbine. Furthermore,
because of their complex shape and because of the size of the
conventional supporting arrangements that must be used for support
and protection during transport, only a relatively small number of
blades can fit into standard transport facilities such as
containers, or into transport vehicles or vessels with standard
container size.
[0004] The same considerations apply to short-term or long-term
storage of blades. Here also, space is associated with cost, and
the large volume occupied by the blades and any supporting or
protective structures results in higher overall costs.
[0005] Another cost factor is given by the need to use an initial
type of support apparatus for storing blades after their
manufacture (for example racks or shelves at the manufacturers
site); a further type of support apparatus for marine or road
transport (for example cradles and/or frames in a transport
vessel); and yet another type of support apparatus for interim
storage before mounting to the hub of a wind turbine (for example
shelves at an owner site). A considerable cost factor is the
transfer of blades from one support apparatus to another, since the
blades must be dismounted from one apparatus and moved or
lifted--taking due care not to damage the blade--to the next
apparatus. The risk of blade damage increases with every transfer
step.
SUMMARY
[0006] It is therefore an advantage to provide an improved blade
handling apparatus, avoiding the disadvantages outlined above.
[0007] This advantage is achieved by the wind turbine blade holding
arrangement and by the method of handling a number of wind turbine
blades as claimed.
[0008] The wind turbine blade holding arrangement comprises a root
frame for securing to a root portion of a blade; an airfoil clamp
for arranging about an airfoil portion of the blade; and an airfoil
frame for supporting the airfoil clamp; wherein the root frame and
tip clamp are realized for use in a first blade orientation in a
first storage and transport stage of the blade and also for use in
a second blade orientation in a second storage and transport stage
of the blade, wherein the first and second blade orientations are
distinct from each other.
[0009] Here, the term "storage and transport stage" is to be
understood to mean any stage between the point in time at which the
blade manufacture and finishing steps are complete, to the point in
time at which the blade is ready to be installed on a wind turbine.
A rotor blade manufacturing site can be remote from the wind
turbine installation site. Usually, long distances by road, rail
and ship must be covered between the manufacturer and the onshore
or offshore installation site. Therefore, it may be necessary to
store a blade for some time before it can be shipped (i.e.
transported from one location to another), then it must be loaded
for shipping. During transport, it may be necessary to unload and
load the blade one or more times, for example from a road transport
vehicle to a transport vessel. These are all various "storage and
transport stages" during which the blade must be handled and moved
in a safe and secure manner.
[0010] An advantage of the wind turbine blade holding is that it
can be used throughout all storage and transport stages of a blade,
from the time the blade manufacture and finishing steps are
complete, to the time the blade is installed on a wind turbine, and
can be adapted to different blade orientation requirements. Various
elements of the holding arrangement remain secured to the blade
throughout, even for distinctly different blade orientations or
positions, until the blade is ready to be mounted to the hub of the
wind turbine. Instead of having to transfer the blade from a
storage holding means (which may require, for example, a
"horizontal" blade orientation) to a different transport holding
means (which may require, for example, a "vertical" blade
orientation), the single holding arrangement can be used
throughout. Since a blade must pass through several storage and
transport stages between manufacture and installation, the holding
arrangement offers a considerable saving in cost, since elements of
the holding arrangement remain attached to the blade throughout its
entire storage and transport phase, and since all storage and
transport steps make use of the elements of the holding
arrangement. Furthermore, since there is no need to transfer the
blade between different types of holding equipment, the reduction
in the number of handling steps means that there is also less risk
of damage to the blades. This also contributes to a reduction in
overall wind turbine cost.
[0011] The method of handling a number of wind turbine blades
comprises the steps of securing a root frame to a root end of a
blade; arranging a tip clamp about an airfoil portion of the blade;
and mounting the tip clamp onto a tip frame; which method comprises
arranging the root frame in a first blade orientation in a first
storage and transport stage of the blade; and arranging the root
frame in a second blade orientation in a second storage and
transport stage of the blade; wherein the first and second blade
orientations are spatially significantly distinct or different from
each other.
[0012] An advantage of the handling method is that the handling
steps in the storage and transport stages between manufacture and
installation of the blade are reduced to a favorable minimum, while
ensuring at the same time that the blade is always safely and
securely held.
[0013] Particularly advantageous embodiments and features of the
invention are given by the dependent claims, as revealed in the
following description. Features of different claim categories may
be combined as appropriate to give further embodiments not
described herein.
[0014] The handling or holding arrangement can be adapted to
securely hold any type or shape of blade during transport and
storage. In the following, but without restricting the invention in
any way, it may be assumed that a wind turbine blade comprises an
essentially circular root portion and an airfoil portion, with a
shoulder or transition region between these. Of course, the root
frame can easily be realized to fit about a root portion that has a
non-circular shape, for example an elliptical shape or other
complex shape.
[0015] As mentioned above, the holding arrangement can hold the
blade in blade orientations that are distinct from each other. For
example, first and second blade orientations may be essentially at
right angles to each other. Of course, the first and second blade
orientations may differ by any suitable angle. In the following,
without restricting the invention in any way, it may be assumed for
simplicity that the first and second blade orientations are at
right angles to each other.
[0016] The airfoil clamp is arranged about the flatter airfoil
section of the blade at point someway beyond the blade middle and
towards the tip, so that the weight of the blade is optimally
supported at two points (by the root frame at one point and by the
airfoil frame and airfoil clamp at another point). In the following
therefore, without restricting the invention in any way, the
airfoil clamp may also be referred to as a "tip clamp", and the
airfoil frame may be referred to as a "tip frame".
[0017] After a manufacturing stage, prior to moving the blade to
storage or transport, the blade may need to be "parked" for a
while. This may also be the case after unloading the blade at a
final destination. Therefore, in an embodiment of the invention,
the holding arrangement also comprises a root end foot realized to
support the root portion of the blade. This root end foot is shaped
to match a portion of the root end, so that it can be placed
between the root end and the ground. The blade can then rest
securely on the root end foot. In such a "parking" position or
vertical blade orientation, the blade is arranged so that its
shoulder and airfoil portion face vertically upward, which is a
stable position for the blade and also occupies less space.
[0018] Such a root end foot comprises some means with which it can
be secured to the root end, so that it remains in place even if the
blade is lifted and/or turned from its "parked" position. To mount
a blade to the hub of a wind turbine, pinbolts are usually threaded
into bushings embedded in the root region of the blade and left to
protrude to a certain extent. These pinbolts can then be inserted
into corresponding bushings in a circular hub connector, for
example to a pitch bearing. Therefore, in a further embodiment of
the invention, the root end foot comprises bolt cover portions
realised for mounting over already installed and protruding
pinbolts of the root end of the blade. For example, a root end foot
may comprise two sections with protruding tubular bolt covers that
fit over a number of neighboring pinbolts. This can be sufficient
to ensure that the root end foot stays in place. The root end foot
may be screwed onto the root end. The root end foot can be made of
some suitable material such as steel, and can be made quite
economically, for example it can be cast in one piece.
[0019] The root frame can be secured in any suitable way to the
root end of the blade. The root frame is secured to the root end so
that the root frame and root end can be handled as a single entity.
Therefore, in an embodiment of the invention, the root frame
comprises a number of root end brackets realized for securing the
root frame to the root end of the blade, using a number of "empty"
pinbolt bushings about a mounting face of the root end. The
embodiment of the invention makes use of the fact that pinbolt
bushings of the blade root end provide a very stable connecting
means for an alternative component, in this case the root frame.
Connecting brackets are attached to the root frame, with openings
that coincide with the positions of several empty pinbolt bushings.
Suitable fasteners can be inserted through these openings and into
the empty pinbolt bushings, and subsequently tightened.
[0020] As indicated above, it would be advantageous if the root end
foot could stay mounted to the blade so that it can be used in both
a first "parking" stage, during which the weight of the root end is
carried by the root end foot, and a final "parking" stage of the
blade during which the weight of the root end is carried by the
root frame. Therefore, in a further embodiment of the invention,
the root frame is realized to accommodate the root end foot, i.e.
the root frame can be constructed to fit about the root end foot.
Equally, the root end foot can be shaped to fit "into" the root
frame. Then, the root frame and blade can be turned from a first
position (in which the root end was resting on the root end foot)
to a second position (in which the root end is held only by the
root frame), without having to remove the root end foot, since this
does not protrude beyond the root frame. This can be used again
later, for example when the root frame is removed, and the weight
of the blade can once again be carried at the root end by the root
end foot.
[0021] When wind turbine blades are stored, in layers, for example
in a storage hall or in the hold of a transport vessel.
Conventional methods involve lifting and moving each blade from a
supporting apparatus (such as a cradle) onto a shelf or rack. The
embodiments of the invention take a different approach, namely that
of using one type of equipment or apparatus to fulfill several
storage and transport functions. In an embodiment of the invention,
a frame is realized to be stacked on a further frame of the same
type. For instance, a root frame can be arranged on another root
frame, so that a root frame stack can be built. Similarly, a tip
frame can be arranged on another tip frame, so that a tip frame
stack can be built.
[0022] To facilitate ease of stacking, the tip clamp and root frame
comprise a number of connecting means for connecting to a lifting
apparatus, for example for connecting to a cable or rope of a crane
that is used to lift the blade and its tip clamp and root frame
from one position to another. Once in the air, the cables can be
manipulated to turn the root frame and tip clamp, for example
through one quarter turn. A winch could be used to achieve the
desired degree of rotation. After turning, the root frame and tip
clamp are in a "horizontal" position or blade orientation, since
the airfoil and shoulder portions of the blade are essentially
lying "flat". The horizontal arrangement can then be lowered into
place on a waiting tip frame, and the tip clamp can be dropped into
the tip frame and secured to this. Thereafter, the blade with tip
clamp, tip frame and root frame can be lifted again and moved to a
new location. For example, the entire arrangement can be lifted as
it is and lowered onto a flatbed lorry or railcar, ready for
transport to a new location. Equally, the entire arrangement can be
lifted as it is and lowered onto a stack of previously assembled
blade and frame arrangements to form a "blade stack", in which all
tip frames are arranged in a vertical "tip frame stack", and all
root frames are arranged in a vertical "root frame stack".
[0023] For ease of assembly when a blade stack is being formed, the
uprights of a frame are shaped to easily fit over the uprights of
the lower frame. To this end, a tip frame or root frame comprises a
first interface portion for connecting with a second interface
portion of a corresponding frame, so that the frames can be
connected to each other. For example, the uprights of a frame can
be shaped so that the top corners are tapered or pointed to fit
into correspondingly formed bottom corners of the next frame in the
stack. A locking device such as a locking pin or clamp can be
implemented to lock the vertically aligned uprights of the stacked
frames.
[0024] It is also important to secure an entire stack to the floor
of the transport and/or storage facility. To this end, the holding
arrangement comprises one or more mounting "feet" or mounting
brackets realized for mounting to a surface of a transport means
and/or a storage facility. Such feet or brackets can be secured to
the ground, and spaced so that the uprights of a frame fit over the
brackets. A mounting foot can be welded in place, or can be
removably secured using a suitable locking device such as a
twist-lock mechanism. The mounting feet and the frames are realized
to be connected together in a secure manner, for example by using a
locking pin passed through a frame upright and a barrel or cylinder
of the mounting foot.
[0025] The uprights of a frame are shaped to easily fit over and
onto the mounting feet. Therefore, a mounting foot comprises a
mounting portion corresponding in shape to a frame interface
portion of a frame. In this way, each frame can be used in any
position in the stack, for example each tip frame can be used as
the lowest tip frame secured to mounting feet on the ground, or as
any intermediate tip frame that is mounted onto another lower tip
frame, etc. No distinction need be made, i.e. any frame can be used
at any position in its stack.
[0026] In another embodiment, the holding arrangement comprises one
or more connecting struts for connecting adjacent frames, for
example for connecting adjacent root frames. In this way,
additional lateral stability can be ensured, especially during sea
transport.
[0027] The compact-realization of the root frames and tip frames
means that blades can be stacked in relatively narrow blade stacks
with a favorable economy of space. Furthermore, since the frames
need not extend to any significant extent beyond the contour or
profile of a blade, it is possible to arrange vertical blade stacks
in an interleaved manner in a close and compact array. For example,
the stacks can be formed such that the airfoils of one stack of
blades can face toward the root portions of a neighboring parallel
blade stack. Blade stacks can be arranged progressively in this
alternating manner to give an interleaved array with two opposite
arrangements of root frames, and two arrangements of tip frames in
between, so that, effectively, twice as many tip frames are
accommodated in the space occupied by one root frame "array". The
root frame stacks can be connected using struts as mentioned above.
To obtain an optimal packing density, the combined width of a root
frame and a connecting strut can correspond essentially to the
width of two tip frames.
BRIEF DESCRIPTION
[0028] Other objects and features of the present invention will
become apparent from the following detailed descriptions considered
in conjunction with the accompanying drawings. It is to be
understood, however, that the drawings are designed solely for the
purposes of illustration and not as a definition of the limits of
the invention:
[0029] FIG. 1 shows a blade in a first storage stage, supported by
a root end foot and a tip clamp of a holding arrangement according
to an embodiment of the invention;
[0030] FIG. 2 shows the blade of FIG. 1, supported also by a root
frame;
[0031] FIG. 3 shows the blade of FIGS. 1 and 2 during a lifting
step;
[0032] FIG. 4 shows a tip clamp and a tip frame of a holding
arrangement according to an embodiment of the invention;
[0033] FIG. 5 shows a detail of frame of a holding arrangement
according to an embodiment of the invention;
[0034] FIG. 6 shows a blade during a road transport stage,
supported by a holding arrangement according to an embodiment of
the invention;
[0035] FIG. 7 shows a vertical stack of blades supported by a
holding arrangement according to an embodiment of the
invention;
[0036] FIG. 8 shows an array of the vertical stacks of FIG. 7;
and
[0037] FIG. 9 shows the array of FIG. 8 arranged on a container
vessel for sea transport.
[0038] In the diagrams, like numbers refer to like objects
throughout. Objects in the diagrams are not necessarily drawn to
scale.
DETAILED DESCRIPTION
[0039] FIG. 1 shows a blade 6 in a first storage stage, supported
by a root end foot 4 and a tip clamp 3 of a holding arrangement
according to an embodiment. In this basic configuration, the root
end 61 is being supported by the root end foot 4, and the blade's
airfoil portion 62 is being supported in an airfoil clamp 3 or "tip
clamp" 3. This position or blade orientation may be required for a
while between the manufacturing and transport phases. The root end
foot 4 is secured to the root end 61 using several of the already
mounted bolts 610 protruding from the root end 61, which will later
be used to mount the blade 6 to the hub of a wind turbine. To this
end, the root end foot 4 includes a planar portion with a number of
rigid protruding tubes that are arranged to coincide with the
positions of certain pinbolts 610. The planar portion of the root
end foot 4 lies against a planar surface of the root end. The root
end foot 4 is compact and economical, since it does not need to
extend around the entire root portion 61. Even so, the sturdy shape
of the root end foot 4 means that it can hold the blade 6 securely.
To this end, the root end foot 4 has relatively wide flat portions
shaped to rest firmly on a horizontal surface such as the ground,
or the interior of a lorry, container, railcar etc., as will be
shown later. The tip clamp 3 or airfoil clamp 3 comprises two
hinged parts or "jaws" 31 that are shaped to conform to the airfoil
shape of the blade 6 at a distance along its length, for example at
a point between the blade middle and the blade tip. The shape of
the tip clamp 3 ensures that the blade 6 can be held securely
without being scratched or dented, and the blade 6 is further
protected by a number of pads 32. The tip clamp 3 is in turn
mounted to a foot 30, which is realized to rest firmly on a
horizontal surface such as the ground, or the interior of a lorry,
container, railcar, etc.
[0040] In this initial stage, the shoulder portion 63 of the blade
points upward in a "vertical" blade orientation V, and the
remainder of the airfoil 61 is also essentially vertical. The tip
clamp 3 and the root end foot 4 are mounted after manufacture of
the blade 6 has been completed, and remain on the blade 6 during
all subsequent transport and storage stages, as will become clear
in the following. At this stage, as shown in the diagram, the tip
clamp 3 is in a "vertical" position V or blade orientation,
pointing upwards.
[0041] FIG. 2 shows the blade 6 of FIG. 1, supported also by a root
frame 1. The blade shoulder 63 is pointing upwards, and the root
frame 1 is in the corresponding "vertical" position as indicated by
the "V" in the diagram. The root end foot 4 and root frame 1 are
designed so that the root end frame 1 can be fitted over the root
end foot 4. The root end frame 1 is shaped to fit about the root
end 61 of the blade 6, and comprises root end brackets 10 that fit
into certain spaces along the bolt ring of the root end 61 in which
no pinbolts have been inserted. In this exemplary embodiment, the
root end frame 1 is secured to the root end 61 by inserting
fasteners through the brackets 10 and into empty pinbolt bushings.
For stability, the root frame 1 can be placed over mounting feet 5,
which can have a wider base to provide support. The mounting feet 5
can be permanently or temporarily secured to a surface such as a
storage facility floor, a truck interior, a storage vessel
interior, etc., as will be explained below. The root frame 1 can be
secured to the mounting feet 5 using a suitable connecting means
such as a locking pin 50. Both root frame 1 and tip clamp 3 have a
number of lifting eyelets 13, 33, to which lifting tackle such as a
crane cable can be connected.
[0042] FIG. 3 shows the blade 6 of FIGS. 1 and 2 during a lifting
step. Here, cables 9 are connected to the lifting eyelets 13, 33 of
the tip clamp 3 and root frame 1. When the blade 6 (with tip clamp
3 and root frame 1) is suspended in the air, the cables 9 can be
adjusted to turn the blade 6 one quarter turn, so that the blade
shoulder 63 lies more or less flat. The root frame 1, since it is
secured to the root portion 61 of the blade 6, has also been
rotated, and is now in the corresponding "horizontal" position as
indicated by the "H" in the diagram. The blade 6 is lowered into
place over a tip frame 2 which has been previously arranged in
place. FIG. 4 shows a tip clamp 3 also in its "horizontal" position
on a tip frame 2 of the holding arrangement. The diagram shows that
the tip clamp 3 and the clamp foot 30 are dimensioned to fit within
the upper portion of the tip frame 2. The tip frame 2 also has
various lifting eyelets 23 for a later transport step. The tip
frame 2 is also realized to fit onto mounting feet 5. A mounting
foot 5 can have a tapered top part, shaped to facilitate ease of
placement of a tip frame 2. Similarly, the uprights of a tip frame
2 can have tapered points so that another tip frame 2 can easily be
stacked onto it.
[0043] FIG. 5 shows a detail of a root frame 1, showing how a
corner of a frame 1, 2 can fit over a mounting foot 5. Suitable
bores in the side portions of the root frame 1 or tip frame 2 allow
a locking pin 50 to be passed through a corresponding barrel or
cylinder of the mounting foot 5.
[0044] FIG. 6 shows a blade 6 during a road transport stage,
supported by a holding arrangement 1, 2, 3 according to an
embodiment. The blade 6 can have been lifted into place onto a
lorry 7 with the root frame 1 and tip frame 2 (and clamp 3) already
in place, using a crane, and cables connected to the lifting
eyelets. The diagram shows that the root frame 1 and tip frame 2
are dimensioned to fit onto a flatbed of the lorry 7. Mounting feet
5 are welded or otherwise secured to the flatbed, and connected to
the frames 1, 2, ensure that the blade is securely held during the
road transport stage. Of course, this arrangement is equally
applicable to rail transport.
[0045] The root frame 1 and tip frame 2 allow blades to be stacked
in a favorably practical manner for storage and transport. FIG. 7
shows a vertical stack of blades supported by a holding arrangement
1, 2, 3 according to an embodiment. Here, four blades 6 are each
held in a root frame 1, and a tip frame 2 with tip clamp 3, and the
frames 1, 2 are stacked one above the other. The uprights of the
frames 1, 2 can be secured to each other using a locking
arrangement, for example locking pins such as those shown in FIG.
5. The lowest root frame 1 and tip frame 2 can be secured to the
ground using mounting feet 5 and locking pins, also as shown in
FIG. 5. Four root frames 1 thus form a vertical root frame stack
100, while four tip frames 2 form a vertical tip frame stack 200.
Such vertical stacks 100, 200 can be combined in an array. For
example, eight blades can be arranged in two vertical stacked
arrangements of the type shown in FIG. 7. Alternatively, in a very
efficient arrangement, arrays of vertical stacks 100, 200 can be
"interleaved". FIG. 8 shows such an array 300 comprising two
interleaved arrays of twelve blades, stacked in three vertical
four-blade stacks 100, 200 as shown in FIG. 7. The two twelve-blade
arrays are arranged so that the twelve blade tips of one array
point toward the root ends of the other array. This is made
possible by the overall narrow dimensions of the tip frames 2 and
root frames 1, which do not extend to any significant extent beyond
the blades themselves. For additional stability, the uppermost root
frames 1 can be secured by struts 101 connected between the
uprights of adjacent root frames 1.
[0046] FIG. 9 shows the array 300 of FIG. 8 arranged on a container
vessel 8 for sea transport, for example to an offshore wind park
installation. The diagram illustrates that a relatively large
number of blades 6 can be accommodated on the vessel 8. Such a
vessel 8 is usually dimensioned to carry a specific number of
standard containers. A three-dimensional array of standard
containers usually fills the rectangular volume of the loading
space more or less exactly, i.e. with little or no "room to spare"
at the sides. The diagram shows that the 24-blade interleaved array
fills such a rectangular volume. This is made possible by
dimensioning the root frames 1, tip frames 2 and connecting struts
101 appropriately. For example, the combined width of three root
frames 1 and two struts 101 is chosen to correspond to an integer
multiple of a container width. Similarly, the combined width of six
tip frames 2 corresponds to the same container width integer
multiple.
[0047] Although the present invention has been disclosed in the
form of embodiments and variations thereon, it will be understood
that numerous additional modifications and variations could be made
thereto without departing from the scope of the invention.
[0048] For the sake of clarity, it is to be understood that the use
of "a" or "an" throughout this application does not exclude a
plurality, and "comprising" does not exclude other steps or
elements.
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