MAST FOR A SHIP OR UNDERWATER VESSEL

Description

[0001] The present invention relates to a mast of the type intended to equip a marine or underwater vessel, the mast comprising a metal structure extending along an axis and a fairing arranged externally relative to the structure in a direction normal to the axis. The invention also relates to a marine or underwater vessel comprising such a mast.

[0002] Document EP 0 269 893 A1 describes a deployable antenna mast, in particular for submarines.

[0003] Marine or submarine vessels usually have superstructures arranged in the form of masts, used in particular to carry measuring and communication instruments, such as sensors or antennas.

[0004] In the case of underwater vessels, these masts also generally include a periscope used to perceive the surroundings during the dive, as well as a fresh air tube intended to allow the operation of the vessel's engines requiring an oxygen supply for combustion.

[0005] It is known to arrange a fairing around the metal structure of such a mast in order to improve the aerodynamic and / or hydrodynamic properties of the mast, as well as to protect the metal structure. The fairing usually consists of a composite skin, arranged around the metal structure of the mast, made for example from a matrix of resin and glass fibers.

[0006] However, such a fairing has many disadvantages.

[0007] First of all, such a fairing is not very resistant to impacts, which can be frequent, especially in the case of underwater vessels, where the mast is submerged and may encounter drifting objects. Damage to the fairing may then require its complete replacement.

[0008] Then, such a fairing does not allow access to the metal structure of the mast, and must be destroyed and replaced when such access is necessary, during maintenance operations for example.

[0009] Finally, such a fairing is expensive, and the assembly procedure is relatively complex.

[0010] An aim of the invention is therefore to provide a mast fairing allowing easy access to the mast structure, and the installation and maintenance of which are simplified.

[0011] For this purpose, the invention relates to a mast according to claim 1.

[0012] According to particular embodiments of the invention, this mast is according to any one of claims 2 to 8.

[0013] The invention also relates to a marine or underwater building comprising at least one mast according to any one of claims 1 to 8.

[0014] The invention will be better understood by reading the following description, given solely by way of example and with reference to the appended drawings, among which: there figure 1 is a side view of an underwater building according to the invention; the figure 2 is a side view of a mast according to a first embodiment of the invention; the figure 3 is an exploded detail view of the mast of the figure 2 ; there figure 4 is a horizontal sectional view of the mast of the figures 2 And 3 ; there figure 5 is a partially exploded side view of a mast according to a second embodiment of the invention; and the figure 6 and a horizontal sectional view of the mast of the figure 5 .

[0015] On the figure 1 , an underwater vessel 10 is shown submerged in a body of water 12, at a shallow depth below a surface 14 of the body of water 12.

[0016] The underwater vessel 10 has two masts 16, extending from an upper turret 20, the masts 16 projecting from the surface 14.

[0017] The masts 16 extend along a substantially vertical axis Z-Z', the axis ZZ' being substantially normal to the surface 14.

[0018] The masts 16 comprise a fresh air tube 22, corresponding to a first embodiment shown in detail in the figures 2 à 4 , and a standard mast 24, corresponding to a second embodiment shown in detail on the figures 5 et 6 .

[0019] The fresh air tube 22, also called a snorkel, comprises a hoistable metal structure 26 extending along the substantially vertical axis ZZ', and a fairing 28 arranged externally with respect to the structure 26 in a direction normal to the axis Z-Z'.

[0020] As shown in the figure 2 , the structure 26 comprises a tube 30 defining an internal conduit opening at an upper end of the tube 30, and adapted to convey air from the exterior to the interior of the building 10 in order to supply motors of the building 10.

[0021] The structure 26 also comprises a frame 34 extending in a direction substantially parallel to the axis Z-Z', in front of the tube 30 in the direction of travel of the underwater vessel 10.

[0022] The frame 34 is for example a bar having a substantially cylindrical elongated shape, secured to the tube 30 at its two ends.

[0023] The fairing 28 is assembled in a removable manner on the structure 26, and received by the frame 34. By removable, it is meant that the fairing 28 can be removed from the structure 26 without significantly damaging either the fairing 28 or the structure 26, so that the same fairing 28 can then be remounted on the structure 26 without requiring repairs or replacement.

[0024] In the first embodiment, the fairing 28 is assembled by elastic fitting onto the frame 34.

[0025] Fairing 28 is shown in detail on the figures 3 et 4 The fairing 28 has an elongated prismatic shape in a direction parallel to the Z-Z' axis, with a substantially triangular arrowhead section, so as to present a hydrodynamic profile.

[0026] The fairing 28 defines a substantially cylindrical housing 40 adapted to receive the frame 34, the housing having an internal diameter equal to or slightly less than a diameter of the frame 34.

[0027] The fairing 28 comprises a deformable portion 42 defining an opening 44 for access to the housing 40.

[0028] In the example shown on the figures 2 à 4 , the fairing 28 is made in a single piece from an elastic material, for example an elastomer. The entire fairing 28 then constitutes the deformable part 42.

[0029] The elastomer is, for example, a high molecular weight polyolefin or a natural or artificial rubber. The elastomer advantageously has a hardness of between 50 Shore A and 80 Shore A, advantageously close to 70 Shore A

[0030] Alternatively, the fairing 28 comprises several parts made from different materials, at least one of which constitutes the deformable part 42.

[0031] As shown in the figure 4 , the opening 44 has a transverse width e smaller than the diameter of the frame 34. The deformable part 42 is therefore elastically clamped around the frame 34 and holds the fairing 28 on the structure 26.

[0032] The opening 44 is capable of deforming so as to increase its transverse width e reversibly and allow the passage of the frame 34 during assembly and disassembly of the fairing 28.

[0033] Advantageously, a contact surface 46 of the fairing 28 on the frame 34 comprises an adhesive improving the fixing of the fairing 28.

[0034] The contact surface 46 extends around the housing 40, in a portion of a cylinder.

[0035] The adhesive is a reversible adhesive, that is to say an adhesive having moderate resistance to shear stresses applied in a direction substantially tangent to the contact surface 46, and low resistance to peel stresses applied in a direction substantially normal to the contact surface 46. The fixing provided by the adhesive is of the type known by the names “temporary bonding”, “repositionable bonding” or “non-permanent bonding”.

[0036] In particular, the reversible adhesive has a shear strength of less than 5 MPa, advantageously less than 1.5 MPa, and a peel strength of less than 2 MPa, advantageously less than 0.5 MPa.

[0037] The low peel strength of the adhesive allows the assembly of the fairing 28 on the structure 26 to remain removable, providing low resistance to peel disassembly of the fairing 28 from the frame 34.

[0038] The adhesive prevents rotational movements of the fairing around the frame 34, which are associated with shear stresses for which the adhesive has greater resistance than peel stresses.

[0039] The fairing 28 according to the first embodiment is also resistant to impacts with drifting objects due to its production in elastomer material, and effectively absorbs vibrations due to drag.

[0040] In the second embodiment, shown in detail in the figures 5 et 6 , the standard mast 24 comprises a structure and a fairing comprising a plurality of distinct segments 50 assembled on the structure and aligned in a direction parallel to the Z-Z' axis.

[0041] Two segments 50 are shown on the figure 5 , one assembled on the structure and the other away from the structure.

[0042] Each segment 50 has an elongated prismatic shape in a direction parallel to the Z-Z' axis, with an arrowhead section shown in detail on the figure 6 .

[0043] Each segment 50 defines a substantially semi-cylindrical housing 52 delimited by a contact surface 54 extending over a rear portion of the segment 50.

[0044] The segments 50 are for example made from a rigid material, in particular a syntactic foam comprising a resin matrix into which hollow glass spheres have been injected.

[0045] Each segment 50 also defines at least one fixing notch 56 opening into the housing 52 and extending over the entire height of the segment 50 in the direction parallel to the axis Z-Z'.

[0046] The segment 50 further defines two substantially cylindrical through openings 58, extending in a direction orthogonal to the axis Z-Z', opening into the notch 56 and on opposite sides of the segment 50.

[0047] In the second embodiment, the structure comprises a post 60 extending in a direction parallel to the axis ZZ' and a plurality of supports 62 projecting from the post 60 in a direction orthogonal to the axis Z-Z'.

[0048] The supports 62 are adapted to engage in the notch 56 of each segment 50 during assembly of the segment 50 on the structure, and thus hold the segment 50 against the structure. The supports 62 engaged in the notch 56 prevent any rotational movement of the fairing 28 around the structure.

[0049] In the example shown, each support 62 defines two fixing orifices 64. The fixing orifices 64 are arranged so that the openings 58 of one of the segments 50 open onto the fixing orifices 64 of two successive supports 62 when the segment 50 is assembled on the structure.

[0050] The fairing 28 then comprises fixing members 66 received in the openings 58 and the orifices 64 so as to ensure the fixing of the segment 50 on the structure. The fixing members 66 are for example bolts.

[0051] In a variant not shown, the supports 62 have a hook shape and are adapted to cooperate with pins arranged in the notch 54 so as to hold the segment 50 against the structure without a fixing member 66.

[0052] The mast 16 according to the second embodiment comprises a fairing 28 assembled in a removable manner, since one or more of the fixing members 66 can be removed in order to dismantle one or more segments 50, which can then be reassembled as is.

[0053] The fairing 28 also allows partial replacement in the event of damage, for example in the event of impact with a drifting object, by replacing only the damaged segments 50.

[0054] The construction of the 28 fairing in syntactic foam allows it to offer excellent resistance to hydrostatic pressures, while maintaining a sufficiently low density.

Claims

1. A mast (16) intended to equip a marine or submarine vessel (10), the mast (16) comprising a metal structure (26) extending along an axis (Z-Z') and a fairing (28) arranged externally to the structure (26) in a direction normal to the axis (Z-Z'), characterized in that the fairing (28) is removably assembled to the structure (26), removably meaning that the fairing (28) can be removed from the structure (26) in particular without damaging the fairing (28) or the structure (26), the structure (26) comprising a post (60) extending in a direction parallel to the axis (Z-Z'), the structure (26) including a plurality of supports (62) protruding from a post (60), the fairing (28) defining a notch (56) receiving the supports (62), the supports (62) keeping the fairing (28) against the structure (26), each support (62) defining at least one attachment orifice (64), the fairing (28) defining at least one opening (58) suitable for emerging on the attachment orifice (64) when the fairing (28) is assembled to the structure (26), the attachment orifice (64) and the openings (58) being able to receive an attachment member (66) of the fairing (28) to the structure (26).

2. The mast (16) according to claim 1, wherein the fairing (28) is assembled by resilient fitting on a frame (34) of the structure (26).

3. The mast (16) according to claim 1 or 2, wherein the fairing (28) defines a housing (40) for receiving the frame (34), the fairing (28) comprising a deformable part (42) defining an access opening (44) to the housing, the opening (44) having a transverse width (e) smaller than a transverse width of the frame (34).

4. The mast (16) according to any one of claims 1 to 3, wherein the fairing (28) is made from an elastomer material.

5. The mast (16) according to any one of claims 1 to 3, wherein the fairing (28) is made from a rigid material, in particular a syntactic foam comprising a matrix of resin and glass microbeads included in the matrix.

6. The mast (16) according to any one of claims 1 to 5, wherein the fairing (28) is made up of a plurality of segments (50) assembled on the structure (26) and aligned in a direction parallel to the axis (Z-Z').

7. The mast (16) according to any one of claims 1 to 6, wherein a contact surface (46) of the fairing (28) on the structure (26) includes a reversible adhesive attaching the fairing (28) to the structure (26).

8. A marine or submarine vessel (10) including at least one mast (16) according to any one of claims 1 to 7.