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Title:
PREFABRICATED STRUCTURE OF A BALCONY FOR A CRUISE SHIP
Document Type and Number:
WIPO Patent Application WO/2021/123999
Kind Code:
A1
Abstract:
The present invention relates to a prefabricated structure of a balcony for a cruise ship, intended to be fixed in particular to a ship side, comprising: at least two support beams (11, 12), provided with elements for coupling to a ship side; a platform (20), which is mechanically connected to the aforesaid two support beams (11, 12) at a lower face opposite to an upper face defining the balcony floor, said platform (20) comprising an inner edge (21) intended in use to face the ship side and an outer edge (22), opposite to the inner edge; a profiled element (30), which is mechanically associated with the platform (20) at said outer edge (22) and is arranged to anchor a parapet. The platform (20) consists of a board defined by two aluminum or aluminum alloy sheets (23, 24), arranged parallel to each other to form a cavity filled with a foam (25) of aluminum or aluminum alloy. The foam (25) structurally connects said two sheets (23, 24) together to form a single body.

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Inventors:
STEFANUTTI LUCIANO (IT)
Application Number:
PCT/IB2020/061479
Publication Date:
June 24, 2021
Filing Date:
December 04, 2020
Export Citation:
Click for automatic bibliography generation   Help
Assignee:
FINCANTIERI SPA (IT)
International Classes:
B63B29/02; E04B1/00
Domestic Patent References:
WO2013122478A12013-08-22
Foreign References:
US6457431B12002-10-01
KR20100043884A2010-04-29
DE20302822U12003-06-12
Attorney, Agent or Firm:
ZANETTIN, Gianluigi et al. (IT)
Download PDF:
Claims:
Claims

1. Prefabricated structure of a balcony for a cruise ship, destined to be fixed in particular to a ship's side, comprising: - at least two support beams (11, 12), provided with coupling elements to a ship's side;

- a platform (20), which is mechanically connected to said two support beams (11, 12) at a lower face opposite an upper face defining the balcony floor, said platform (20) comprising an inner edge (21) destined in use to face the ship's side and an outer edge (22), opposite the inner edge;

- a profiled element (30), which is mechanically associated to the platform (20) at said outer edge (22) and is predisposed to anchor a parapet, characterised in that said platform (20) consists of a board defined by two sheets of aluminium or aluminium alloy (23, 24), arranged parallel to each other to form a cavity filled with a foam (25)of aluminium or aluminium alloy, said foam (25) structurally connecting said two sheets (23, 24) together to form a single body.

2. Prefabricated structure according to claim 1, wherein said two sheets (23, 24) are made of an aluminium alloy with magnesium and silicon, preferably an alloy of the 6000 series, even more preferably an aluminium alloy

6082.

3. Prefabricated structure according to claim 1 or 2, wherein each of said two aluminium sheets (23, 24) is between 2 mm and 5 mm thick. 4. Prefabricated structure according to any of the preceding claims, wherein said foam (25) of aluminium or aluminium alloy has a density between 0.5 and 2.0 g/cm3.

5. Prefabricated structure according to any of the preceding claims, wherein said aluminium foam or aluminium alloy (25) occupies a volume between 65% and 75% of the total volume of the board, and preferably 70% of the total volume of the board.

6. Prefabricated structure according to any of the preceding claims, wherein said foam (25) consists of an aluminium alloy with magnesium and silicon, preferably an alloy of the 6000 series, even more preferably an aluminium alloy 6082, preferably said foam having a density between 1.5 and 2.0 g/cm3, and even more preferably equal to 1.9 g/cm3. 7. Prefabricated structure according to any of the claims from 1 to 6, wherein said foam (25) is made of an aluminium alloy with magnesium, preferably an alloy of the 5000 series, even more preferably an aluminium alloy 5754, preferably said foam having a density between 0.5 and 1.0 g/cm3, and even more preferably equal to 0.7 g/cm3.

8. Prefabricated structure according to any of the preceding claims, wherein said board has a total thickness of between 40 mm and 50 mm, and preferably equal to 45 mm.

9. Prefabricated structure according to any of the preceding claims, wherein said platform (20) has the outer edge (22) shaped according to a non-straight, preferably curved, profile. 10. Prefabricated structure according to claim 9, wherein the outer edge (22) of said platform (20) is shaped by milling or water jet cutting.

11. Prefabricated structure according to any of the preceding claims, wherein said platform (20) is connected to said support beams (11, 12) by bolting, preferably said bolting involving only the foam (25) and the sheet (23) defining the lower face of the platform (20).

12. Prefabricated structure according to any of the preceding claims, wherein said profiled element (30) comprises:

- a first C-shaped portion (31), at which said profiled element is coupled to the platform (20) along the outer edge (22); and a second C-shaped portion (32), which serves as a housing seat for a parapet.

13. Prefabricated structure according to any of the preceding claims, comprising a water gutter (40), associated to one of the edges (21, 22) of the platform, preferably the inner edge (21). 14. Prefabricated structure according to claim 13, wherein said water gutter (40) is made of aluminium or aluminium alloy and is connected to said platform by welding, preferably with FSW (Friction Stir Welding) technique. 15. Prefabricated structure according to any of the preceding claims, wherein said platform (20) extends in length parallel to said inner edge (21) to define only a balcony of a single cabin of a ship.

16. Prefabricated structure according to any of the claims from 1 to 14, wherein said platform (20) extends in length parallel to said inner edge (21) to define the balconies of two or more consecutive cabins of a ship, preferably said platform (20) being constituted by two or more of said boards welded together transversely to the direction of extension in length so as to form a single body.

17. Prefabricated structure according to claim 16, wherein said two or more boards are welded together two by two at the respective two sheets (23, 24) using FSW (Friction Stir Welding) technique.

Description:
DESCRIPTION

"PREFABRICATED STRUCTURE OF A BALCONY FOR A CRUISE SHIP"

FIELD OF APPLICATION

[0001]The present invention relates to a prefabricated structure of a balcony for a cruise ship.

[0002]In particular, the prefabricated structure of a balcony for a cruise ship according to the invention can be used to construct the balconies of passenger cabins on cruise ships. [0003]Advantageously, such a prefabricated structure can be used both to construct the balcony of a single cabin separately, and to construct the balconies of two or more adjacent cabins in a single body.

BACKGROUND ART [0004]As is known, the balconies of cruise ship cabins are constructed by means of prefabricated structures, which are fixed to the sides of the ships by special anchoring systems.

[0005]The construction of the balconies using prefabricated structures has now almost entirely replaced the traditional technique, which involves constructing the structures of the balconies by means of portions of the decks extending in a cantilevered manner from the sides. [0006]This traditional technique involved the welding of metal sheets and did not allow constructing completely satisfactory structures from an aesthetic point of view. In fact, the shrinkages caused by the welding led to undulations in the sheet metal forming the balcony platform, thus creating irregularities on the visible surface of the balcony floor, to the detriment of the aesthetic finish of the balcony itself.

[0007]These problems have been completely solved with prefabricated balconies. [0008]Typically, as shown in Figure 1, a prefabricated balcony structure comprises:

[0009]- at least two support beams T, provided with elements for coupling to the ship side M;

[0010]- a platform P, mechanically connected to the aforesaid two support beams;

[0011]- a coaming Q, mechanically associated with the outer edge of the platform (opposite that facing the side), and arranged to anchor a parapet B;

[0012]- a water gutter S, integrated between the coaming and the platform.

[0013]Generally in these prefabricated structures, the platforms consist of prefabricated boards in aluminum extrusion or aluminum honeycomb.

[0014]More in detail, as shown in Figure 2, the extrusion boards consist of two aluminum plates, which form the two main faces of the board, and of inner connecting elements between the two plates. Generally, such inner connecting elements consist of a series of ribs L3 parallel to each other, arranged along the length of the platform. Alternatively, such inner connecting elements can consist of honeycomb structures. The board is thus an internally hollow, resistant, and light structure.

[0015]The platform is fixed to the support beams by welding and/or bolting. [0016]The prefabricated structures described above are ideal for constructing balconies with a straight outer profile, but they are unsuitable for constructing balconies with a shaped outer profile (not straight, for example curved) . In fact, in the latter case the platforms should be shaped along the outer edge thereof by cutting operations. Such cutting operations would not only affect the structural integrity of the platforms (cutting the inner connecting elements) with inevitable deterioration of the mechanical seal of the same structure, but would also cause the platform to open, internally exposing it to the accumulation of water and dirt and therefore to corrosion phenomena. The operations for restoring the structural integrity of the platform after such cutting operations are so complex and expensive that the use of the prefabricated balcony is uneconomical .

[0017]For such reasons, currently the balconies which must have curvilinear outer profiles are constructed by means of the traditional technique, i.e., constructing the platforms with sheets welded to the sides or decks. In fact, the sheets can be easily shaped without compromising the structural strength thereof in any manner.

[0018]In recent years, following an increasingly driven trend to characterize the aesthetics of cruise ships, there is the need to create an increasing number of balconies with a shaped, non-straight outer profile.

[0019]To date, for the reasons set out above, this need cannot be satisfied using prefabricated balcony structures, but only by constructing the balconies using the traditional technique with sheet metal platforms. This results in a significant increase in costs being the number of balconies constructed equal.

[0020]There is therefore a need, still unsatisfied today, to construct prefabricated balcony structures with shaped platforms in an economically sustainable manner, without necessarily having to resort to sheet metal platforms. PRESENTATION OF THE INVENTION

[0021]It is the object of the present invention to provide a prefabricated structure of a balcony for a cruise ship which can be constructed economically with a non-straight shaped outer profile and is simultaneously structurally resistant.

BRIEF DESCRIPTION OF THE DRAWINGS [0022]The technical features of the invention according to the aforesaid objects may be clearly found in the contents of the claims hereinbelow and the advantages thereof will become more apparent from the following detailed description, given with reference to the accompanying drawings which show one or more embodiments merely given by way of non-limiting example, in which: [0023]- figure 1 shows a prefabricated balcony structure of the traditional type, with a platform made from an aluminum extrusion board, associated with a ship side; [0024]- figure 2 diagrammatically shows a prefabricated balcony structure with a platform made from aluminum alloy extrusion boards, partially shown in section to show the inner shape thereof;

[0025]- figure 3 shows an orthogonal side view of a prefabricated balcony structure for a cruise ship according to a particular embodiment of the invention, shown associated with a ship side;

[0026]- figure 4 shows a diagrammatic perspective view of a prefabricated balcony structure for a cruise ship according to a first embodiment of the invention which provides a platform with a straight outer edge;

[0027]- figure 5 shows a diagrammatic perspective view of a prefabricated balcony structure for a cruise ship according to a second embodiment of the invention which provides a platform with an outer edge shaped according to a curvilinear profile and with a water gutter made by an aluminum foam structure;

[0028]- figure 6 shows a diagrammatic top plan view of a prefabricated balcony structure for a cruise ship according to a particular embodiment of the invention which includes a platform with an outer edge shaped according to a curvilinear profile, in which the platform consists of three boards welded together;

[0029]- figure 7 shows a photograph of a portion of a board used to construct the platform of a prefabricated balcony structure for a cruise ship according to the invention;

[0030]- Figure 8 shows a photograph of three pieces of aluminum foam board, each of which is obtained by welding with the FSW technique (Friction Stir Welding) of two pieces of board, by the interposition of an aluminum alloy bar; and

[0031]- Figure 9 shows a diagrammatic perspective view of a prefabricated structure of a balcony for a cruise ship according to an alternative embodiment of the invention which provides a platform with an outer edge shaped according to a curvilinear profile and with a water gutter constructed with an aluminum extrusion profile which is hollow inside. DETAILED DESCRIPTION

[0032]The present invention relates to a prefabricated structure for a balcony of a cruise ship.

[0033]The prefabricated structure of a balcony for a cruise ship according to the invention has been indicated by reference numeral 1 in the accompanying drawings.

[0034]Advantageously, the prefabricated structure 1 can be used to construct the balconies of passenger cabins. In particular, such a prefabricated structure 1 can be used both to construct the balcony of a single cabin separately, and to construct the balconies of two or more adjacent passenger cabins in a single body.

[0035]As shown in Figure 3, the prefabricated structure 1 is intended to be fixed to a ship side M.

[0036]In general, as shown in particular in Figures 4 and 5, the prefabricated balcony structure 1 comprises at least two support beams 11 and 12, provided with elements (diagrammatically shown with 50 in Figure 3) for coupling to a ship side. Preferably, at the coupling area, the side is arranged with counter-shaped elements, which allow a quick coupling of the prefabricated structure to the side itself. Advantageously, the fixing can be structurally completed by means of welding and/or bolting.

[0037]The prefabricated balcony structure 1 comprises a platform 20, which is mechanically connected to the aforesaid two support beams 11, 12 at a lower face opposite to an upper face defining the balcony floor.

[0038]The platform 20 comprises an inner edge 21 intended in use to face the ship side and an outer edge 22, opposite to the inner edge.

[0039]Generally, as shown in Figures 4, 5 and 6, the inner edge 21 has a straight profile to allow the platform to adhere to the side. The outer edge 22 can have any profile according to the specific aesthetic requirements. In particular, the outer edge 22 can be straight (Fig. 4) or be curvilinear (Figs. 5 and 6).

[0040]The prefabricated structure 1 also comprises a profiled element 30, which is mechanically associated with the platform 20 at the aforesaid outer edge 22 and is arranged to anchor a parapet (diagrammatically shown with 60 in Figure 3).

[0041]According to the invention, as diagrammatically shown in Figures 4 and 5, the aforesaid platform 20 consists of a board defined by two aluminum or aluminum alloy sheets 23 and 24, which are arranged parallel to each other to form a cavity filled with a foam 25 of aluminum or aluminum alloy. The foam 25 structurally connects the two sheets 23, 24 together to form a single body. [0042]An example of a board used to construct the platform

20 according to the invention is shown in the photograph of figure 7. In the following, this type of board will also be referred to briefly as "aluminum foam board".

[0043]The replacement of traditional aluminum extrusion or honeycomb boards with an aluminum foam board allows to construct platforms with outer edges having any profile, without requiring special processing aimed at restoring the structural integrity of the board and therefore the mechanical features thereof. [0044]More in detail, the aluminum foam ensures a substantially continuous structural connection between the two sheets 23 and 24 in all portions of the board, by virtue of the fact that it fills the entire gap between the two sheets. Therefore, an aluminum foam board can be shaped by cutting at any point without losing structural integrity, since the connection between the two sheets 23 and 24 is always ensured.

[0045]Differently, in the aluminum boards traditionally used to construct the balcony platforms, with inner ribbing or with a honeycomb structure, the connection between the sheets is not always ensured. In the first case because the contact points are limited, in the second because the honeycomb structure forms a discontinuous element between the two sheets. Such boards, if cut and shaped, lose the structural integrity thereof at the portion subjected to cutting, as this operation involved the discontinuous connection elements. [0046]Operatively, therefore, after cutting/shaping an aluminum foam board does not require operation for restoring structural integrity and can be used as a board not subjected to cutting.

[0047]Preferably, the aforesaid two sheets 23, 24 of the aluminum foam board are made of an aluminum alloy with magnesium and silicon, preferably an alloy of the 6000 series commercially known as Anticorodal.

[0048]In particular, the 6000 series alloys (main alloying agents: magnesium 0.4-1.7% by weight, manganese 0.5-1% by weight and silicon 1-5% by weight) are characterized by good mechanical features and excellent corrosion resistance and thus are suitable to be used in the naval field. In particular, the two sheets 23, 24 can be made of 6082 aluminum alloy.

[0049]Preferably, each of the two aluminum sheets 23, 24 has a thickness between 2 mm and 5 mm, and even more preferably equal to 2.5 mm. [0050]In accordance with a preferred embodiment, the board has a total thickness between 40 mm and 50 mm, and preferably equal to 45 mm.

[0051]Preferably, the aluminum or aluminum alloy foam 25 occupies a volume between 65% and 75% of the total volume of the board, and preferably equal to 70% of the total volume of the board.

[0052]The production techniques of an aluminum foam board are per se well known to those skilled in the art and will not be described in detail here.

[0053]The production of aluminum foam can occur through different processes, which depend on the state of the starting metal: liquid, powder, in the vapor phase or as metal ions. [0054]Preferably, the board 20 used in the present invention is made from a foam produced from metal powder mixed with a foaming agent, typically a metal hydride. The two components are mixed and extruded and then heated to produce bubbles in the molten metal. This technique (compared to other production processes) allows obtaining a foam with a more homogeneous density between the two aluminum sheets.

[0055]Preferably, the aluminum or aluminum alloy foam 25 has a density between 0.5 and 2.0 g/cm3. This is the compromise solution between a rigid structure but at the same time as light as possible (increasing the density increases the rigidity of the structure, but in the same manner increases the weight thereof).

[0056]According to a first embodiment, the foam 25 consists of an aluminum alloy with magnesium and silicon, preferably an alloy of the 6000 series commercially known as Anticorodal. In particular, the foam 25 is made of the same alloy used to form the two sheets 23, 24, for example an aluminum alloy 6082. [0057]Preferably, if an alloy of the 6000 series is used, the foam has a density between 1.5 and 2.0 g/cm3, and even more preferably equal to 1.9 g/cm3.

[0058]According to a second embodiment, the foam 25 consists of an aluminum alloy with magnesium, preferably an alloy of the 5000 series, commercially known as

Peraluman.

[0059]More specifically, the alloys of the 5000 series have magnesium as the main alloying agent thereof (up to 5.6% by weight). Magnesium gives these alloys excellent features of resistance to corrosion, even in a marine environment, good weldability features and excellent ductility. Therefore, they are also suitable to be used in the naval field.

[0060]In particular, the foam 25 can be made of aluminum alloy 5754. [0061]Preferably, if an alloy of the 5000 series is used, the foam has a density between 0.5 and 1.0 g/cm3, and even more preferably equal to 0.7 g/cm3.

[0062]As already mentioned, the inner edge 21 of the platform 20 has a straight profile to allow the platform itself to adhere to the side. Instead, the outer edge 22 can have any profile according to the specific aesthetic requirements to be obtained.

[0063]Preferably, as shown in Figures 5 and 6, the outer edge 22 has a curvilinear profile.

[0064]Cutting of aluminum foam boards can be made by milling or by unconventional methods, including laser, plasma, and water jet cutting.

[0065]Laser and plasma cutting are electro-thermal technologies, which transfer thermal energy from the electrical power source to the surface of the material being processed. In particular, among the various types of laser cutting, that which best suits metal foams is the fibre laser. [0066]Instead, water jet cutting is a mechanical process and involves a high-pressure water jet, which can possibly be added with abrasives.

[0067]In this specific case, mechanical processing is preferable, as it involves a lower heat input, to prevent the heat from deforming the material. [0068]Preferably, the outer edge 22) of the platform 20 is shaped by milling or by water jet cutting.

[0069]The connection of the platform 20 to the support beams 11, 12 can be achieved by means of any technique, in particular by welding and/or bolting.

[0070]Preferably, the aforesaid platform 20 is connected to the support beams 11, 12 by bolting.

[0071]The bolted connection is preferred over the welded connection since, unlike welding, it does not involve significant thermal input. The risk of heat-induced deformation of the platform can therefore be avoided.

[0072]The choice of the bolted connection is made possible by the presence of the foam 25 between the two sheets 23 and 24, as the foam gives continuity to the material. Differently, the aluminum boards traditionally used to construct balcony platforms must necessarily be welded to the support beams as, being hollow inside, they do not allow a rigid connection to be obtained, as the structure would behave like a cantilevered beam. [0073]Preferably, the bolting involves only the foam 25 and the sheet 23 defining the lower face 20a of the platform 20, while it does not affect the sheet 24 defining the upper face 20b of the platform. This prevents the bolting from interfering with the aesthetic finish of the balcony floor. [0074]As previously mentioned, the prefabricated structure 1 comprises a profiled element 30, which is mechanically associated with the platform 20 at the aforesaid outer edge 22 and is arranged to anchor a parapet 60. [0075]Preferably, as shown in particular in Figures 4 and

5, the aforesaid profiled element 30 comprises:

[0076]- a first C-shaped portion 31, at which the profiled element is coupled to the platform 20 along the outer edge 22; and [0077]- a second C-shaped portion 32, which serves as a housing seat for a parapet 60.

[0078]In particular, the first portion C 31 of the profiled element 30 allows a shape coupling of the profiled section 30 with the platform 20. This solution can always be adopted since the platform 20 made from an aluminum foam board always remains intact and resistant even if the outer edge 22 is cut/shaped.

[0079]Preferably, in addition to the connection by shape coupling, the profiled element 30 can be connected to the platform by welding and/or by bolting.

[0080]Advantageously, the prefabricated structure 1 according to any one of the preceding claims comprises a water gutter 40, associated with one of the edges 21, 22 of the platform 20. [0081]Preferably, as shown in the accompanying Figures, the gutter 40 is associated with the inner edge 21 of the platform 20, so as to release the connection thereof from the shape of the outer edge 22, which as mentioned may not be straight. [0082]If the outer edge 22 has a straight profile, the gutter 30 can be associated with the platform 20 along the outer edge 22 as well.

[0083]Advantageously, the aforesaid water gutter 40 can be made of aluminum or aluminum alloy and be connected to the platform by welding, preferably with the FSW

(Friction Stir Welding) technique.

[0084]In particular, the gutter 40 can be made with an extruded aluminum profile (hollow inside; as diagrammatically shown in Figure 9) or it can also be made from a portion of an aluminum foam board, like the platform 20 (as diagrammatically shown in Figures 4 and 5).

[0085]As already mentioned above, the prefabricated structure 1 can be used, in particular both to construct the balcony of a single cabin separately, and to construct the balconies of two or more adjacent passenger cabins in a single body.

[0086]In the first case (single balcony), the platform 20 extends in length parallel to the inner edge 21 to define only a balcony of a single cabin of a ship. Advantageously, taking into account the fact that generally a balcony has an extension in length of about 3m, the platform 20 can preferably be obtained from a single aluminum foam board having the size, for example, of 3m x 2m.

[0087]In the second case (multiple balcony), the platform 20 extends in length parallel to the inner edge 21 to define the balconies of two or more consecutive cabins of a ship. Preferably, in this case, the platform 20 consists of two or more single prefabricated boards (for example of size 3mx2m) welded together transversely to the direction of extension in length so as to form a single body.

[0088]In Figure 6, the individual prefabricated boards (welded together two by two) are indicated by reference numerals 20', 20" and 20'", while the welding lines are shown in dashed lines and indicated by X.

[0089]Preferably, the aforesaid two or more boards are welded together two by two at the respective two sheets 23, 24 by means of the FSW (Friction Stir Welding) technique.

[0090]The FSW welding technique is well known per se to those skilled in the art and will not be described in detail here. It is a type of solid-state friction welding in which the melting temperature is not reached in the material to be welded, but in 75-80% thereof.

[0091]Advantageously, since the aluminum foam only has the function of connecting the two sheets 23, 24 together, keeping them at a predefined distance, the welding can be limited only to the aluminum sheets. Preferably, as shown in Figure 8, the welding is achieved by interposing an aluminum bar 25 between the two sheets at the junction area between the two welded board elements.

[0092]As an alternative to the FSW technique, the welding can be achieved with the material addition technique. However, compared to the FSW technique, the material addition solution causes the formation of a welding seam protruding from the outer surface of the board. For reasons related to surface finish, the metal stock of the seam must be removed at least at the top face of the board. This involves a lengthening of times and costs compared to the FSW technique.

[0093]The steps of a possible process for producing a prefabricated structure of a balcony for a cruise ship according to the invention are described, and in particular as described above.

[0094]The first operating step a) is to prepare the aluminum foam boards to construct a platform 20. [0095]Preferably, said boards are prefabricated and have predefined dimensions. Advantageously, the single board is made with dimensions corresponding to the dimensions of the platform of a balcony for a single cabin. Thereby, if a prefabricated balcony structure for a single balcony is to be made, it is sufficient to use a single board.

[0096]The second operating step b) is to weld two or more of said boards together, if a platform must be made having greater dimensions than those of the single board, as in the case of a prefabricated balcony structure for multiple balconies. However, such a second step b) is not necessary if the single board already has the dimensions of the platform. This occurs if the prefabricated structure to be constructed is a single balcony. It can also occur if a board already having the dimensions of the platform is used to create a prefabricated structure with multiple balconies. However, this situation is not preferred as it would mean managing (production, transport, and storage) boards of double or triple dimensions, at least in length. [0097]Preferably, the welding between boards is achieved by means of the FSW technique.

[0098]The third operating step c) is to shape, preferably by milling or water jet cutting, the outer edge 22 of the platform 20, according to the desired profile, in particular curved as shown for example in Figure 6. [0099]The fourth operating step d) is to prepare the platform 20 for connection with the support beams. In particular, this step d) can comprise at least partial drilling of the platform to obtain seats for inserting the fixing bolts at the lower face of the platform itself. Preferably, as previously described, the drilling of the platform is carried out so as not to affect the sheet 24 defining the upper face 20b of the platform. This prevents the bolting from interfering with the aesthetic finish of the balcony floor.

[00100] The fifth operating step e) is to couple, preferably by bolting, the support beams to the platform at the lower face 20b thereof. The support beams have been prepared in a specific operating step of component preparation.

[00101] The sixth operating step f) is to couple the profiled element 30 (provided for anchoring a parapet to the platform 20). The profiled element 30 has been prepared in a specific operating step of component preparation. In particular, the profiled element 30 has been previously shaped, for example by calendaring, so as to adapt to the profile of the outer edge of the platform. The fixing of the profiled element to the platform preferably occurs by welding and/or bolting. [00102] Then follows a step g) of finishing the prefabricated structure. In particular, this step g) can comprise:

[00103] - the application of a coating of the upper face 20b of the platform board, with sanding and finishing thereof; the coating can be, for example, in imitation teak;

[00104] - the assembly of the parapet and any dividers between the balconies of adjacent cabins. k ~k [00105] The invention allows to obtain several advantages, some of which have already been pointed out previously.

[00106] The prefabricated structure of a balcony for a cruise ship according to the invention can be constructed economically with an outer profile which is possibly also not straight and simultaneously structurally resistant. [00107] The replacement of traditional aluminum extrusion or honeycomb boards with an aluminum foam board allows to construct platforms with outer edges having any profile, without requiring special processing aimed at restoring the structural integrity of the board and therefore the mechanical features thereof.

[00108] In fact, the aluminum foam ensures a substantially continuous structural connection between the two sheets in all portions of the board, by virtue of the fact that it fills the entire gap between the two sheets. Therefore, an aluminum foam board can be shaped by cutting at any point without losing structural integrity, since the connection between the two sheets is always ensured.

[00109] This feature also facilitates the connection to the platform of further components which form part of the prefabricated structure, in particular the profiled element supporting a parapet. [00110] Therefore, the invention thus conceived achieves the intended purposes.