WO2010105626A2

WO2010105626A2 - A wind turbine blade transport casing

Info

Publication number: WO2010105626A2
Application number: PCT/DK2010/050061
Authority: WO
Inventors: Rune Kirt; Mads Bækgaard Thomsen; Duncan Galbraith
Original assignee: Vestas Wind Systems A/S
Priority date: 2009-03-18
Filing date: 2010-03-16
Publication date: 2010-09-23
Also published as: WO2010105626A3

Abstract

The invention relates to a wind turbine blade transport casing. The casing (5a, 5b) has a first part (6a, 6b) and a second part (7a, 7b), the first and the second part, when assembled, forming an inner surface corresponding to a section of a wind turbine blade (100) to be transported. The first part and the second part each constitutes a substantially solid body, the predominate part of each solid body being a synthetic polymer, such as a thermoplastic like PP or PU etc. The first and the second part form a self-supporting structure when assembled and transporting a wind turbine blade. The invention provides better protection of the wind turbine blades during transportation. Additionally, the present invention may result in more efficient handling of the blades because fewer or no change of transport casings may be required during the transport from manufacturing site or factory to the actual site of erection of the wind turbine generator (WTG).

Description

A WIND TURBINE BLADE TRANSPORT CASING

FIELD OF THE INVENTION

The present invention relates to a wind turbine blade transport casing for efficient transportation of wind turbine blades. The invention also relates to a corresponding method for transporting wind turbine blades and a corresponding transportation system for transporting wind turbine blades.

BACKGROUND OF THE INVENTION

Raising a wind turbine in an appropriate location, both with respect to wind and the impact on the surrounding environment, may posses a significant task. Thus, the cost associated with transport of the wind turbine generator (WTG) may presently be as high as 20% of the equipment cost itself.

Within the field of wind turbines, the transportation problems are currently growing correspondingly with the increase in the size of the wind turbines. Thus, blades or rotor diameters are currently approaching a length of 50 meters, which represent a technical challenge in many aspects.

During the transportation by ship, railway, or truck, the wind turbine blades are usually stored in dedicated frames that protect the blades against external impacts, such as shocks and vibrations that may negatively influence the operation and/or life time of the wind turbine blades.

International patent application WO2006061806 discloses a recent solution for handling the logistics of wind turbine blades. The solution consists of a packing device for logistics of groups of wind turbine rotor blades, preferably of pairs of blades, including at least two structures, each one having a peripheral frame. For guaranteeing the proper conditions for the logistics, said blades are supported and fastened to the structures by flexible belts stressed by ratchets, being said blade profile partially or entirely enveloped by said flexible belts. The casings should either be transported back to the wind turbine blade factory, or discarded after use. Both options may represent a waste of resources. Furthermore, this solution has the disadvantage that the packing device has some relatively complicated structures for holding the flexible belts that may not be sufficiently stable or reliable during extended transportation and in particular during reloading from one transportation form to another transportation form, e.g. from truck to ship, etc. In order to prevent fatal external impacts on the blades, the structure should preferably be quite strong and stable. If the casings are not sufficiently strong and stable for the upcoming transportation form, the wind turbine blades may have to be reloaded into another kind of transport casing, which takes precious time and resources.

Other solutions are represented by casings where the wind turbine blades rest in dedicated steel frames that are relatively heavy and complicated, and accordingly, expensive to manufacture. Accordingly, these steels frames are often transported back to the wind turbine blade manufacturing site, which complicates logistics even further.

Hence, an improved wind turbine blade transport casing would be advantageous, and in particular a more efficient and/or reliable casing would be advantageous.

OBJECT OF THE INVENTION

It is a further object of the present invention to provide an alternative to the prior art.

In particular, it may be seen as an object of the present invention to provide a wind turbine blade transport casing that solves the above mentioned problems of the prior art with complicated and/or expensive transportation of wind turbine blades.

SUMMARY OF THE INVENTION

Thus, the above described object and several other objects are intended to be obtained in a first aspect of the invention by providing a wind turbine blade transport casing, the casing comprising : - a first part and a second part, the first and the second part, when assembled, forming an inner surface corresponding to a section of a wind turbine blade to be transported, wherein the first part and the second part each constitutes a substantially solid body, the predominate part of each solid body being a synthetic polymer, and wherein the first and the second part, when assembled and transporting a wind turbine blade, form a self-supporting structure.

The invention is particularly, but not exclusively, advantageous for obtaining a better protection of the wind turbine blades during transportation. Additionally, the present invention may result in more efficient handling of the blades because fewer or no change of transport casings may be required during the transport from manufacturing site or factory to the actual site of erection of the wind turbine generator. In that way, the lifting or moving gear may never touch the wind turbine blade itself, only the transport casing surrounding the blades, and thereby one possible risk factor of transportation damage is significantly lowered, possible eliminated.

The invention may further optimise the logistics of wind turbine blades because the transport casings according to the present invention are relatively easy to manufacture, and after use they may be disposed on the site of erection of the wind turbine generator. Preferably, they may be recycled in an appropriate recycling system for synthetic polymers, e.g. plastics. The current practise of transporting the dedicated blade casings back to the manufacturing site or factory may thereby also be superseded.

It is also envisioned that it is possible, within the teaching and principle of the present invention, to design a wind turbine transport casing that may fit the requirements and demands during all, or almost all, of the logistic chain from manufacturing, the internal transport on the manufacturing site, and storage (and possible stacking during storage), and, similarly, the requirements and demands imposed by the logistic chain during road transport, sea transport (including by barge), rail transport, and the transitions between the latter three kinds of transportation, e.g. embarkation to a ship or unloading from a rail wagon. It should be noted that this is currently not possible, because of the different, and some times even conflicting, requirements from various means of wind turbine blade transportation.

Within the context of the present invention, it is to be understood that the inner surface, formed by the first and second part of the transport casing, has a shape or profile that corresponds to the shape or profile of the blade to be transported in the sense that the inner surface and the surface blade are relatively close to each other. In particular, the gap should so be as little as possible so that the casing provides optimum protection and support of the blade during transport. Thus, an average gap of maximum 20 cm, preferably maximum 10 cm, or more preferably maximum 5 cm is acceptable.

Within the context of the present invention, it is to be understood that transport casing is a self-supporting structure in the sense when transporting a wind turbine blade the transport casing is able to mechanically stand alone for an extended period of time without substantially deteriorating, i.e. no auxiliary or assisting structure is needed. Nevertheless, in some embodiments, in particular for very large wind turbine blades there may be provided an additional frame structure around the transport casing, e.g. a wooden frame or a steel frame to further support and protect the transport casing.

Within the context of the present invention, it is to be understood that transport casing may comprise more parts than two, i.e. the said first and the said second part of the casing. Thus, in some embodiments, the transport casing may comprise 3, 4, 5, 6 or more parts, each part being a substantially solid body made mainly of synthetic polymer. In some embodiment, the various parts may be manufactured in different kind of synthetic polymers.

In one embodiment, the synthetic polymer, with respect to bulk volume, may a major part of the first and the second part of the transport casing. Thus, holes and/or voids may be present within the bulk volume as it is well-known within the field of polymer manufacturing. In some cases, it may even be desirable to have voids or holes in order to reduce the amount of material used, and hence the material cost and the impact on the environment. In some embodiments, the ratio of synthetic polymer to the bulk volume may be at least 50%, 60%, 70%, 80%, or 90%.

In another embodiment, a supporting structure may be embedded within the first and the second solid part, the supporting structure having a larger strength and/or stiffness relative to the synthetic polymer. Thus, a grid, a web etc. may be inserted to support and sustain the polymer and thereby improve the overall mechanical strength of the casing.

Preferably, the transport casing, when assembled, may form a substantially planar bottom surface in order to have a stable contact to the underlying support or ground.

In an advantageous embodiment, at least part of the surface of the first and/or the second part may comprise a second synthetic polymer. The second polymer may be a protecting polymer coating, preferably with higher hardness/density than the first polymer. Thus, certain outer areas may be sprayed with protective coating. The inside surface which touches the blade may be coated with softer protective coating to provide blade surface protection and friction grip on blade. Advantageously, the inner surface corresponding to the section of a wind turbine blade may therefore comprise a second synthetic polymer, the second polymer being more elastic and/or having a higher friction towards a wind turbine blade as compared to the first synthetic polymer constituting the main part of the transport casings.

Typically, the synthetic polymer is a thermoplastic, preferably en expanded thermoplastic. Alternatively, a thermosetting polymer may used. For certain examples a non-exhaustive list may include polypropylene (PP), polyethylene (PE), polyurethane (PU), polyamide (PA), polystyrene (PS), polycarbonate (PC), etc. including any combinations and modifications thereof. The first and the second solid part may preferably have a sufficient density and strength so as to enable carrying at least a substantial part of a wind turbine blade to be transported. In some configurations with two transport casings carrying a single blade, about 80- 90% of the weight is carried at the root end, and about 10- 20% of the weight is carried at tip end. Preferably, a safety margin should be implemented into the design.

Typically, the first and the second solid part may have a sufficient density and strength so as to withstand a pressure from the wind turbine blade to be transported on the first and/or second part of at least 10 tons/m², preferably at least 20 tons/m², more preferably at least 30 tons/m² .

Typically, the synthetic polymer may have a density of approximately 0.100-1.200 kg/m³, preferably approximately 0.150-0.800 kg/m³, more preferably approximately 0.200-0.600 kg/m³ in order to provide the necessary strength to the casing.

For improved transportation, the first and second part may be adapted for entering in a mutually locking relationship preventing the first and/or second part from being relatively displaced under transportation, thus protrusions may be fitted in corresponding holes on a counterpart, and so forth.

Beneficially, one or more recesses may be positioned on the surface of the first and/or the second part so as to facilitate one or more circumferential straps to keep the first and the second part in a fixed relation to each other.

For certain configurations, the bottom and top surface of the transport casing may be adapted for entering in a mutually locking relationship with another corresponding transport casing so as to prevent the two transports casings from being relatively displaced under transportation. This may facilitate stacked configurations of wind turbine blades during transportation and storage.

In a second aspect, the present invention relates to a method for transporting at least one wind turbine blade in one or more transport casings, the method comprises

- providing a first part and a second part, and

- assembling the first and the second part to form an inner surface corresponding to a section of a wind turbine blade to be transported, wherein the first part and the second part each constitutes a substantially solid body, the predominate part of each solid body being a synthetic polymer, and wherein the first and the second part, when assembled and transporting a wind turbine blade, form a self-supporting structure.

Beneficially, the method may further comprise stacking at least two wind turbine blades by positioning corresponding transport casings on top of each other. Further, the wind turbine blades may be stacked in alternating and opposite direction with respect to their tip and root ends because this improved storage volume and increase stability.

In a third aspect, the present invention relates to a system for transporting a wind turbine blade in one or more transport casings, the transport casing comprising : - a first part and a second part, the first and the second part, when assembled, forming an inner surface corresponding to a section of a wind turbine blade to be transported, wherein the first part and the second part each constitutes a substantially solid body, the predominate part of each solid body being a synthetic polymer, and wherein the first and the second part, when assembled and transporting a wind turbine blade, form a self-supporting structure

Thus, the present invention may be readily implemented in already existing transportation system for wind turbine generator parts, in particular wind turbine blades.

The first, second and third aspect of the present invention may each be combined with any of the other aspects. These and other aspects of the invention will be apparent from and elucidated with reference to the embodiments described hereinafter.

BRIEF DESCRIPTION OF THE FIGURES

The invention will now be described in more detail with regard to the accompanying figures. The figures show one way of implementing the present invention and is not to be construed as being limiting to other possible embodiments falling within the scope of the attached claim set.

Figure 1 is a perspective drawing of an embodiment according to the present invention with two transport casings carrying a wind turbine blade,

Figure 2 is an exploded perspective drawing similar to Figure 1,

Figure 3 is a more detailed perspective drawing of a transport casing according to the present invention,

Figure 4 is a plan view drawing of the transport casing shown in Figure 3,

Figure 5 is a detailed perspective drawing of another transport casing according to the present invention,

Figure 6 is a plan view drawing of the transport casing shown in Figure 5,

Figure 7 is a perspective drawing of another embodiment according to the present invention with two transport casings in wooden frames,

Figures 8 and 9 show a perspective view and a side view, respectively, of a stacked wind turbine blade embodiment according to the present invention,

Figures 10-12 show various photographs of some preliminary tests performed by the applicant, and

Figure 13 is a flow chart of a method according to the invention.

DETAILED DESCRIPTION OF AN EMBODIMENT

Figure 1 shows a perspective drawing of an embodiment with two transport casings 5a and 5b carrying a wind turbine blade 100. Each wind turbine blade transport casings 5a or 5b comprises a first part 6a or 6b and a second part 7a or 7b. When assembled, the casing, 5a and 5b, forms an inner surface corresponding to a section of a wind turbine blade 100 to be transported. The first part, 6a and 6b and the second part, 7a and 7b, each constitutes a substantially solid body, the predominate part of each solid body being a synthetic polymer. The first and the second part in combination forms a self-supporting structure in the sense that when transporting a wind turbine blade the transport casing, 5a and 5b, is able to mechanically stand alone for an extended period of time without substantially deteriorating.

For merely illustrative purpose, a person P is drawn next to the wind turbine blade 100 being carried by the two transport casings 5a and 5b according to the present invention. The blade 100 is 44 meters long but it is to be understood that the teaching and principles of the invention may of course readily be applied to most sizes and shapes of blades. The advantages of the present invention are nevertheless more readily obtained for relatively large blades used in modern wind turbines generators, e.g. with blade lengths above 20 meters, above 30 meters, or above 40 meters.

In Figure 1, and the remaining Figures described below, two transport casings 5a and 5b are applied to carry the wind turbine blade 100, but the teaching and principle of the present invention is not limited to any specific number of transport casings. Thus, 3, 4, 5, 6 or more casings could be applied within the context of the present invention. It is also contemplated that in some configurations just one casing may be applied, for instance if the casing is more extended, as compared to the shown width, and, if needed, the blade is supported otherwise.

The two transport casings, 5a and 5b, shown in Figure 1 are situated at or near the tip end and root end, respectively, of the wind turbine blade 100. The root end is adapted to for mounting on a hub or spinner (not shown) of an assembled wind turbine generator.

Figure 2 is an exploded perspective drawing similar to Figure 1. In this drawing, it is more evident that the first and second part in combination, i.e. 6a with 7a and 6b with 7b, forms an inner surface corresponding to a section of a wind turbine blade 100 to be transported.

Figure 3 is a more detailed perspective drawing of a transport casing 5a positioned near the tip end of the blade.

In part A of Figure 3, a portion of Figure 1 is shown. Part A shows the two parts, 6a and 7a, of the transport casing 5a in an assembled configuration with blade part 100'.

In part B of Figure 3, an enhanced view is provided without the blade 100'. The first 6a and second part 7a in combination forms a box-shaped casing 5a with a substantially planar bottom so as to provide a stable connection to the ground where the casing is standing. In some embodiments, the bottom may be provided with several extensions or "legs" (not shown) to provided some distance to the ground, e.g. for protection against dust, dirt and/or fluids on the ground.

On the top and side of the first 6a and the second part 7a of the casing, two recesses 30 and 31 are positioned on the surface so as to facilitate one or more circumferential straps (not shown here, cf. Figures 10-12) to keep the first 6a and the second part 7a in a fixed relation to each other during transportation and/or storage.

In part C of Figure 3, a corresponding exploded view of part B is shown. In this part, it is also possible to see the recess 35a and 35b formed in the interface between the first part 6a, the second 7a part, and the space where the section of the wind turbine blade is positioned. The recess 35 has the function of providing space between the trailing edge of the blade and the transport casing leaving the edge untouched during transport and storage. This may beneficial because the trailing edge of the blade is relatively thin and therefore rather fragile as compared to other parts of the blade.

Figure 4 is a plan view drawing from three different view points of the transport casing shown in Figure 3 but without the blade part 100'. The drawings are not to scale, but some preferred dimensions are shown in centimetres. Part A of Figure 4 is a top view showing again the strap recesses 30 and 31 formed in the first 6a and the second 7a part of the transport casing 5a.

Part B of Figure 4 is a front view of the first 6a and the second 7a part of the transport casing 5a. In this view, it may be appreciated that the cross-section of the blade, i.e. the air foil shape, is positioned with a certain angle with respect to horizontal. Thus, it this embodiment the angle is approximately 45 degrees, but the present invention is not limited to any particular angle of inclination for the blade, i.e. angles like 0, 10, 20, 30, 40, 50, 60, 70, 80, or 90 degrees is also envisioned with the teaching and principles of the present invention.

Part C of Figure 4 is side view of the first 6a and the second 7a part of the transport casing 5a. Again, the recesses 30 and 31 formed in the first 6a and the second 7a part are visible.

Figure 5 is a detailed perspective drawing of another transport casing 5b positioned near the root end of the blade, cf. Figure 1.

In part A of Figure 5, a portion of Figure 1 is shown. Part A shows the two parts, 6b and 7b, of the transport casing 5b in an assembled configuration with blade part 100".

In part B of Figure 5, an enhanced view is provided without the blade 100". The first 6b and second part 7b in combination forms a box-shaped casing 5b with a substantially planar bottom so as to provide a stable connection to the ground where the casing is standing.

On the top and the side of the first 6b and the second part 7b of the casing, two recesses 50 and 51 are positioned on the surface so as to facilitate one or more circumferential straps (not shown here, cf. Figures 10-12) to keep the first 6b and the second part 7b in a fixed relation to each other during transportation and/or storage. In part C of Figure 5, a corresponding exploded view of part B is shown. In this part, it is also possible to view the recess 55 formed in the interface between the first part 6b, the second 7b part, and the space where the section of the wind turbine blade is positioned. Again, the recess 55 serves the purpose of protecting the trailing edge of the blade.

In this embodiment, the first 6b and second part 7b are adapted for entering in a mutually locking relationship preventing the first and second part from being relatively displaced under transportation by protrusions 55a and 56a extended from the first part 6b, the protrusion being fitted in corresponding recesses or holes 55b and 56b on the counterpart i.e. the second part 7b.

Figure 6 is a plan view drawing of the transport casing shown in Figure 5 from three different view points of the transport casing shown in Figure 5, but without the blade part 100". The drawings are not to scale, but some preferred dimensions are shown in centimetres.

Part A of Figure 6 is a top view showing again the strap recesses 50 and 51 formed in the first 6b and the second 7b part of the transport casing 5b.

Part B of Figure 6 is a front view of the first 6b and the second 7b part of the transport casing 5b.

Part C of Figure 6 is side view of the first 6b and the second 7b part of the transport casing 5b. Again, the recesses 50 and 51 formed in the first 6b and the second 7b part are visible.

Figure 7 is a perspective drawing of another embodiment with two transport casings 5a' and 5b' positioned at the tip and root end of the blade 100. Each casing is additionally supported in wooden frames 700a and 700b, respectively, in order to provide further support and protection of the transport casings 5a' and 5b' and the blade 100 during transportation. The frames 700a and 700b may be manufactured in various kinds of materials, e.g. steels, plastic, fibre-enforced polymers, etc. The material is preferably disposable under appropriate local environmental requirements like the first and the second part of the transport casing.

Figures 8 and 9 show a perspective view and a side view, respectively, of a stacked configuration with three wind turbine blades 100, 100' and 100' according to the present invention.

The blades are preferably stacked in a so-called "nose-to-tail" configuration, equivalent to a root-to-tip configuration, where the blade tip (or root) direction is alternating in each layer of the stacked configuration.

Thus, in Figures 8 and 9, the lower-most blade 100' has its tip end pointing in the left direction and an appropriate casing 5a" for the tip direction is provided at that end of the blade 100'. At the other of the blades 100", a corresponding root transportation casing 5b" is provided. The blade 100' has the opposite orientation, i.e. the blade root is pointing to the left in these Figures. Likewise, an appropriate transport casing 5b' is provided to support the blade 100' at that end. In the opposite tip end, a tip transport casing 5a' is accordingly provided to support that end of the blade 100'. Similarly, on the upper-most layer, the blade 100 has its tip end pointing to the left (like the lower-most blade 100'), and appropriate transport casings 5a and 5b are positioned to support the blade 100.

It should be mentioned that in the stacked configuration, the transport casings 5 should be dimensioned and configured to support any blades being positioned above that layer. Thus, transport casing 5a" and 5b" should be able to sustain and support the weight of the blade 100" plus the additional weight of the two blades 100' and 100. Similarly, the transport casing 5a' and 5b' should also be able to support the weight of the above blade 100.

The transport casings 5 may designed and dimensioned to sustain one or more above lying blades, or the transport casing 5 may alternatively be designed to a support no above lying blades. Figures 10-12 shows various photographs of some preliminary tests performed by the applicant.

Figure 10 shows the second part of a tip end transport casing, cf. figures 3 and 4 and the corresponding part of the description above. Holes were moulded into the tip casing for the banding strops so as to give a better grip on the blade. Subsequent trials and lifts showed that they are not required.

The banding strops are not part of the lifting gear, but bind the two transport casing halves (i.e. the first and the second part) together around the blade (not shown). The area of the casing in contact with the blade may be lined with white expanded polypropylene (EPP) foam to provide protection and grip so as to prevent the blade from sliding forwards. The lifting slings can be seen under the casing section.

Figure 11 shows a blade in a root end transport casing (part A) and a blade in another root end transport casing (part B) being lifted by slings around the transport casings, cf. figures 5 and 6 and the corresponding part of the description above. The blade is 44 metres long, the weight is about 20 tonnes and it makes an angle of approximately 5 degrees with horizontal in the casings.

During a storage test there was no apparent blade or casing damage or deflection after 7 days standing in the casings.

Figure 12 shows a blade being lifted in a tip end transport casing.

Figure 13 is a flow chart of a method according to the invention. The method is applied for transporting at least one wind turbine blade 100 in one or more transport casings, 5a and/or 5b, the method comprises

51 providing a first part, 6a and/or 7a, and a second part, 6b and/or 7b, and

52 assembling the first and the second part to form an inner surface corresponding to a section of a wind turbine blade 100 to be transported, wherein the first part, 6a and/or 7a, and the second part, 6b and/or 7b, each constitutes a substantially solid body, the predominate part of each solid body being a synthetic polymer, and wherein the first and the second part, when assembled and transporting a wind turbine blade, form a self-supporting structure.

Although the present invention has been described in connection with the specified embodiments, it should not be construed as being in any way limited to the presented examples. The scope of the present invention is set out by the accompanying claim set. In the context of the claims, the terms "comprising" or "comprises" do not exclude other possible elements or steps. Also, the mentioning of references such as "a" or "an" etc. should not be construed as excluding a plurality. The use of reference signs in the claims with respect to elements indicated in the figures shall also not be construed as limiting the scope of the invention. Furthermore, individual features mentioned in different claims, may possibly be advantageously combined, and the mentioning of these features in different claims does not exclude that a combination of features is not possible and advantageous.

Claims

1. A wind turbine blade transport casing, the casing comprising :

- a first part and a second part, the first and the second part, when assembled, forming an inner surface corresponding to a section of a wind turbine blade to be transported,

wherein the first part and the second part each constitutes a substantially solid body, the predominate part of each solid body being a synthetic polymer, and wherein the first and the second part, when assembled and transporting a wind turbine blade, form a self-supporting structure.

2. The wind turbine blade transport casing according to claim 1, wherein the synthetic polymer, with respect to bulk volume, is a major part of the first and the second part of the transport casing.

3. The wind turbine blade transport casing according to claim 1, wherein a supporting structure is embedded within the first and the second solid part, the supporting structure having a larger strength and/or stiffness relative to the synthetic polymer.

4. The wind turbine blade transport casing according to claim 1, wherein the transport casing, when assembled, forms a substantially planar bottom surface.

5. The wind turbine blade transport casing according to claim 1, wherein at least part of the surface of the first and/or the second part comprises a second synthetic polymer.

6. The wind turbine blade transport casing according to claim 5, wherein the inner surface corresponding to the section of a wind turbine blade comprises a second synthetic polymer.

7. The wind turbine blade transport casing according to claim 1, wherein the synthetic polymer is a thermoplastic, preferably en expanded thermoplastic.

8. The wind turbine blade transport casing according to claim 1, wherein the first and the second solid part have a sufficient density and strength so as to enable carrying at least a substantial part of a wind turbine blade to be transported.

9. The wind turbine blade transport casing according to claim 5, wherein the first and the second solid part have a sufficient density and strength so as to withstand a pressure from the wind turbine blade to be transported on the first and/or second part of at least 10 tons/m², preferably at least 20 tons/m², more preferably at least 30 tons/m² .

10. The wind turbine blade transport casing according to claim 8 or claim 9, wherein the synthetic polymer has a density of approximately 0.100-1.200 kg/m³, preferably approximately 0.150-0.800 kg/m³, more preferably approximately 0.200-0.600 kg/m³.

11. The wind turbine blade transport casing according to claim 1, wherein the first and second part are adapted for entering in a mutually locking relationship preventing the first and/or second part from being relatively displaced under transportation.

12. The wind turbine blade transport casing according to claim 1, wherein one or more recesses is positioned on the surface of the first and/or the second part so as to facilitate one or more circumferential straps to keep the first and the second part in a fixed relation to each other.

13. The wind turbine blade transport casing according to claim 1, wherein the bottom and top surface of the transport casing are adapted for entering in a mutually locking relationship with another corresponding transport casing so as to prevent the two transports casings from being relatively displaced under transportation.

14. A method for transporting at least one wind turbine blade in one or more transport casings, the method comprises

- providing a first part and a second part, and - assembling the first and the second part to form an inner surface corresponding to a section of a wind turbine blade to be transported,

15. The method according to claim 14, wherein the method comprises stacking at least two wind turbine blades by positioning corresponding transport casings on top of each other.

16. The method according to claim 15, wherein the wind turbine blades are stacking in alternating and opposite direction with respect to their tip and root ends.

17. A system for transporting a wind turbine blade in one or more transport casings, the transport casing comprising :

wherein the first part and the second part each constitutes a substantially solid body, the predominate part of each solid body being a synthetic polymer, and wherein the first and the second part, when assembled and transporting a wind turbine blade, form a self-supporting structure