[0001] The invention relates to a heavy duty monopile fastening system for retaining a monopile
of a windmill during transport, comprising a frame for supporting the monopile, which
frame comprises supporting elements at a predetermined distance from each other, which
distance is selected to enable the frame to receive and support the monopile.
[0002] EP 3 109 531 discloses such a system for retaining an elongated monopile during transport ashore
or offshore on sea. The known system comprises two pivotable supporting elements which
are arranged at a distance from each other that during use support the monopile. The
monopile is secured against movement in the longitudinal direction by friction between
the supporting elements and the monopile. The pivotable supporting elements are actuated
by hydraulic cylinders to position them with the proper orientation to receive and
support the monopile.
[0003] It is a disadvantage of the known system for retaining an elongated monopile that
it requires ancillary equipment like the hydraulic cylinders which makes the system
relatively costly and also subject to regular maintenance in order to secure its proper
operation.
[0004] It is remarked that from
DE 41 23 430 a retaining element of
plastic is known, for holding at least one pipe or cable with a bearing portion mountable
on a support and a holding portion with two opposing shell parts interconnected in
a lower region of these parts, which are connected on both sides of said lower portion
with a resilient intermediate piece, which merges into a storage area, wherein the
shell parts in their upper region are connectable to each other via engagement elements,
and wherein the shell parts each have an elastic web interconnecting and attached
to an inner and an outer end of the shell parts for holding pipes of different diameters.
This retaining element of
DE 41 23 430 is obviously not suitable for the heavy-duty application to retain a monopile of
a windmill during transportation. It therefore does not relate to the subject matter
of the instant invention.
[0005] It is an object of the invention to provide a monopile fastening system of simpler
and therewith cheaper design, which hardly requires maintenance, if any at all.
[0006] It is a further object of the invention to provide a monopile fastening system which
is capable of receiving and supporting monopiles in a vast range of different diameters.
[0007] It is still a further object of the invention to provide a monopile fasting system
which is equipped to be used with relatively large diameter monopiles and without
damaging such monopiles that are more prone to be indented due to their disadvantageous
ratio of wall thickness versus diameter.
[0008] Still a further object of the invention is to provide a monopile fasting system which
is capable to compensate the limited capacity of cranes that are used to handle monopiles
of relatively large weight.
[0009] The heavy duty monopile fastening system of the invention has the features of one
or more of the appended claims.
[0010] According to a first aspect of the invention the supporting elements are embodied
as vertically straight uprising standards, wherein at least a first vertically straight
uprising standard is provided with at least one pivotable and upstanding substantially
straight arm having its pivot in common with the first vertically straight uprising
standard, and that at least one flexible element or band is provided to connect the
first vertically straight uprising standard with a second vertically straight uprising
standard, wherein the at least one flexible element or band is embodied with two extremities
distant from each other, and that a first extremity of the at least one flexible element
or band connects to the upstanding arm at a position distant from the pivot which
the arm has in common with the first vertically straight uprising standard, and that
a second extremity of the at least one flexible element or band connects to the second
vertically straight uprising standard.
[0011] Since it concerns a heavy-duty system, same cannot be embodied in plastic. Usually
the supporting construction of the system -except for the at least one flexible element
or band- is embodied in a construction metal, preferably steel.
[0012] The construction of the heavy duty monopile fastening system of the invention provides
that it is essentially a self-adjusting system which is capable to receive and support
monopiles of different diameters, without need to make much adjustments to the system.
The system employs gravity in that the heavy weight of the monopile itself arranges
for a close engagement of the flexible element or band against the outer circumference
of the monopile which secures that the monopile is safeguarded against longitudinal
motion by friction, and secured against lateral motion by the suspension between the
vertically straight uprising standards.
[0013] Although some variation is allowed it is preferable that the second extremity of
the at least one flexible element or band has a point of engagement with the second
vertically uprising standard at a height which is level or approximately level with
a height at which the first extremity of the at least one flexible element or band
connects to the upstanding arm when said arm is in an upright orientation.
[0014] The construction with the at least one pivotable and upstanding arm having its pivot
in common with the first vertically uprising standard arranges that the flexible element
or band will tightly engage and to the largest possible extent against the circumference
of the monopile, which is beneficial for providing the largest possible frictional
contact area between the at least one flexible element or band and the monopile.
[0015] It is further preferable that at or near the connection of the at least one flexible
element or band with the upstanding arm of the first vertically uprising standard
and at or near the point of engagement of the at least one flexible element or band
with the second vertically uprising standard, engagement blocks are provided for engaging
and resting against the monopile. These engagement blocks are preferably of rubber
or caoutchouc and can provide a further frictional contact with the monopile and may
prevent damage to the monopiles, such as indents in the outer surface of the monopiles.
[0016] The functionality of the engagement blocks can be optimized by arranging that each
engagement block is provided with a curved surface that approximately matches the
curvature of the monopile to be supported.
[0017] Although the basic construction of the monopile fastening system as discussed hereinabove
is already capable to receive and support monopiles of different diameters, this capability
can be further promoted by arranging that the flexible element or band is length-adjustable.
[0018] In one embodiment the first standard and/or the second standard is provided with
multiple connectors for the at least one flexible element or band. This feature provides
an easy way when the length of the at least one flexible element or band is to be
adjusted and tailored to the diameter of the monopiles to be supported.
[0019] The capability to receive and support monopiles of different diameters can be further
promoted by arranging that the first and second vertically uprising standards are
movable with respect to each other.
[0020] Particularly when the first and second vertically uprising standards are movable
with respect to each other, but also in other situations, stability of the construction
according to the invention can be promoted by arranging that the first and second
vertically uprising standards are provided with at least one distance arm to secure
a predetermined distance between the first and second vertically uprising standards.
[0021] It is beneficial that the distance arm has a feature selected from a group of features
comprising an adjustable length by intermediate pieces, a telescopically extendable
extension part, several connecting hooks at different locations along the length of
the distance arm. Any such feature can be applied for arranging that a suitable distance
arm or distance arms can be applied for promoting stability of the construction according
to the invention.
[0022] Preferably the at least one distance arm is mounted adjacent to a lowest part of
the at least one flexible element or band.
[0023] Further it is preferable that at ground-level the first and second vertically uprising
standards are connected with harmonica arms. This is not only beneficial for securely
moving the first and second vertical standards into a selected distance from each
other, but is also beneficial for arranging that the vertically uprising standards
are collectively movable to and fro a crane for handling monopiles. This enables that
even a crane of limited capacity can be used for handling relatively heavy monopiles.
[0024] Preferably the vertically uprising standards are mounted on rails. The rails can
like the crane be mounted on a ship or be mounted on shore.
[0025] The invention will hereinafter be further elucidated with reference to the drawing
of some exemplary embodiments of a monopile fastening system according to the invention
that is not limiting as to the appended claims.
[0026] In the drawing:
- figure 1 shows a monopile fastening system according to the invention as mounted on
a ship;
- figure 2 shows the monopile fastening system of figure 1;
- figure 3 schematically shows the use of a monopile fastening system of the invention
with different diameter monopiles;
- figure 4 shows an embodiment of the monopile fastening system of the invention suitable
for adjusting to different length of flexible element or bands;
- figure 5 shows several distance arms for use with a monopile fastening system of the
invention; and
- figure 6 shows the mobile fastening system of the invention embodied with harmonica
arms at ground-level.
[0027] Whenever in the figures the same reference numerals are applied, these numerals refer
to the same parts.
[0028] Making reference to figure 1 a monopile fastening system 1 is shown at the railings
at opposite sides of a ship 2 for retaining monopiles 3 during transport.
[0029] As is better shown in figure 2 the system 1 of the invention comprises a frame 4
for supporting the monopile or monopiles, which frame 4 comprises supporting elements
5, 6 at a predetermined distance from each other, which distance is selected to enable
the frame 4 to receive and support the monopiles. The supporting elements 5, 6 are
embodied as separate vertically straight uprising standards 5', 6', wherein at least
a first vertically uprising standard 5' is provided with one or more pivotable and
upstanding substantially straight arms 7. Each arm 7 has its pivot 8 in common with
the first vertical standard 5'.
[0030] Further figure 2 shows that one or more flexible element or bands 9 are provided
to connect the first vertically straight uprising standard 5' with a second vertically
straight uprising standard 6'. For each flexible element or band 9 it holds that it
is embodied with two extremities 9', 9'' distant from each other, and that a first
extremity 9' of the at least one flexible element or band 9 connects to the upstanding
arm 7 at a position distant from the pivot 8 which the arm 7 has in common with the
first vertically uprising standard 5'. A second extremity 9'' of the at least one
flexible element or band 9 which is distant from the first extremity 9' connects to
the second vertically uprising standard 6'.
[0031] Figure 3 schematically shows in a side view a part of the monopile support system
of the invention wherein different diameter monopiles 3 are supported, notably monopiles
3 of 8 m, 8.5 meters and 9 m diameter. With reference to both figure 3 and figure
4 is shown that the second extremity 9" of the at least one flexible element or band
9 has a point of engagement with the second vertically uprising standard 6' at a height
which is level or approximately level with a height at which the first extremity 9'
of such at least one flexible element or band 9 connects to the upstanding arm 7 when
said arm 7 is in an (approximately) upright orientation.
[0032] Figures 2, 3 and 4 show that at or near the connection of the at least one flexible
element or band 9 with the upstanding arm 7 of the first vertically uprising standard
5' and at or near the point of engagement of the at least one flexible element or
band 9 with the second vertically uprising standard 6', engagement blocks 10, 11 are
provided for engaging and resting against the monopile 3. The engagement blocks 10,
11 can be flat or have a curved surface.
[0033] Figures 3 and 4 show that each engagement block 10, 11 is provided with a curved
surface 10', 11' that approximately matches the curvature of the monopile 3.
[0034] To match different length of the flexible element or band or flexible element or
bands 9 it is shown in figure 4 that the second standard 6' is provided with multiple
connectors 12 for the at least one flexible element or band 9. This could likewise
be embodied on the upstanding arm 7 or another part of the first standard 5'.
[0035] Figure 6 depicts that the first and second vertically uprising standards 5', 6' are
movable with respect to each other. This is in this example embodied with harmonica
arms 13, 14 connecting the separate first and second vertically uprising standards
5', 6' at ground-level. Going from left to right in figure 6 the harmonica arms 13,
14 are shown in a collapsed situation, a half angled orientation, and in a straight
orientation in each-others extended direction, thus providing for less or more room
between any combination of first vertical standard 5' and second vertical standard
6' of the frame.
[0036] Turning back to figure 2 it is shown that the first and second vertically uprising
standards 5', 6' are provided with at least one distance arm 15 to secure a predetermined
distance between the first and second vertically uprising standards 5', 6'. The at
least one distance arm 15 is mounted adjacent to a lowest part of the at least one
flexible element or band 9 to provide best results in stability. Figure 2 also shows
that when multiple flexible element or bands 9 are used, the flexible element or bands
9 can cross each other.
[0037] Particularly but not only in relation to the movability of the first and second vertically
uprising standards 5', 6', the distance arm 15 has a feature selected from a group
of features comprising an adjustable length by intermediate pieces 15' (see figure
5 - in the middle), a telescopically extendable extension part 15'' (see figure 5
- top), several connecting hooks 15''' at different locations along the length of
the distance arm 15 (see figure 5 - bottom). With any one of these features stably
maintaining the distance between the first and second vertical standards 5', 6' can
be maintained over their entire height.
[0038] Turning back to figure 1 it is remarked that the frame 4 comprising the vertically
uprising standards is movable to and fro a crane 16 for handling the monopiles 3.
For this purpose it is appropriate that the vertical standards of the frame 4 are
mounted on and movable over rails 17.
[0039] Although the invention has been discussed in the foregoing with reference to an exemplary
embodiment of the monopile fastening system of the invention, the invention is not
restricted to the particular embodiments as discussed herein, which can be varied
in many ways without departing from the invention. The discussed exemplary embodiments
shall therefore not be used to construe the appended claims strictly in accordance
therewith. On the contrary the embodiments are merely intended to explain the wording
of the appended claims without intent to limit the claims to these exemplary embodiments.
The scope of protection of the invention shall therefore be construed in accordance
with the appended claims only, wherein a possible ambiguity in the wording of the
claims shall be resolved using these exemplary embodiments.
1. Heavy duty monopile fastening system (1) suitable for retaining a monopile (3) of
a windmill during transport, comprising a frame (4) for supporting the monopile (3),
which frame (4) comprises supporting elements (5, 6) at a predetermined distance from
each other, which distance is selected to enable the frame (4) to receive and support
the monopile (3), characterized in that the supporting elements (5, 6) are embodied as separate vertically straight uprising
standards (5', 6'), wherein at least a first vertically straight uprising standard
(5') is provided with at least one pivotable and upstanding substantially straight
arm (7) having its pivot (8) in common with the first vertically straight uprising
standard (5'), and that at least one flexible element or band (9) is provided to connect
the first vertically straight uprising standard (5') with a second vertically straight
uprising standard (6') which is separate from the first vertically straight uprising
standard (5'), wherein the at least one flexible element or band (9) is embodied with
two extremities (9', 9'') distant from each other, and that a first extremity (9')
of the at least one flexible element or band (9) connects to the upstanding arm (7)
at a position distant from the pivot (8) which the arm (7) has in common with the
first vertically straight uprising standard (5'), and that a second extremity (9")
of the at least one flexible element or band (9) connects to the second vertically
straight uprising standard (6').
2. Monopile fastening system according to claim 1, characterized in that the second extremity (9") of the at least one flexible element or band (9) has a
point of engagement with the second vertically uprising standard (6') at a height
which is level or approximately level with a height at which the first extremity (9')
of the at least one flexible element or band (9) connects to the upstanding arm (7)
when said arm (7) is in an upright orientation.
3. Monopile fastening system according to claim 1 or 2, characterized in that at or near the connection of the at least one flexible element or band (9) with the
upstanding arm (7) of the first vertically uprising standard (5') and at or near the
point of engagement of the at least one flexible element or band (9) with the second
vertically upright standard (6'), engagement blocks (10, 11) are provided for engaging
and resting against the monopile (3).
4. Monopile fastening system according to any one of claims 1 - 3, characterized in that each engagement block (10, 11) is provided with a curved surface (10', 11') that
approximately matches the curvature of the monopile (3).
5. Monopile fastening system according to any one of claims 1 - 4, characterized in that the flexible element or band (9) is length-adjustable.
6. Monopile fastening system according to any one of claims 1 - 5, characterized in that the first standard (5') and/or the second standard (6') is provided with multiple
connectors (12) for the at least one flexible element or band (9).
7. Monopile fastening system according to any one of claims 1 - 6, characterized in that the first and/or second vertically upright standards (5', 6') are movable with respect
to each other.
8. Monopile fastening system according to any one of claims 1 - 7, characterized in that the first and second vertically upright standards (5', 6') are provided with at least
one distance arm (15) to secure a predetermined distance between the first and second
vertically upright standards (5', 6').
9. Monopile fastening system according to claim 8, characterized in that the distance arm (15) has a feature selected from a group of features comprising
an adjustable length by intermediate pieces (15'), a telescopically extendable extension
part (15''), several connecting hooks (15''') at different locations along the length
of the distance arm (15).
10. Monopile fastening system according to any one of claims 7 - 9, characterized in that the at least one distance arm (15) is mounted adjacent to a lowest part of the at
least one flexible element or band (9).
11. Monopile fastening system according to any one of claims 7 - 10, characterized in that at ground-level the first and second vertically upright standards (5', 6') are connected
to each other with harmonica arms (13, 14).
12. Monopile fastening system according to any one of claims 1 - 11, characterized in that the vertically upright standards (5', 6') are collectively movable to and fro a crane
(16) for handling monopiles (3).
13. Monopile fastening system according to claim 12, characterized in that the vertically upright standards (5', 6') are mounted and movable on rails (17).