Mast of marine or submarine building

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

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

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 engines of the vessel requiring a supply of water. oxygen for combustion.

It is known to have 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.

However, such a fairing has many drawbacks.

First of all, such a fairing is not very resistant to shocks, which can be frequent in particular in the case of underwater vessels, for which the mast is submerged and may encounter drifting objects. Damage to the fairing may then require its complete replacement.

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.

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

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

To this end, the invention relates to a mast of the aforementioned type, characterized in that the fairing is assembled in a removable manner to the structure.

According to particular embodiments of the invention, this mast has one or more of the following characteristics, taken in isolation or in any technically feasible combination:

- the fairing is assembled by elastic fitting on a frame of the structure;

the fairing defines a housing for receiving the frame, the fairing comprising a deformable part defining an opening for access to the housing, the opening having a transverse width smaller than a transverse width of the frame;

- The structure comprises a plurality of supports projecting from a post, the fairing defining a notch receiving the supports, the supports holding the fairing against the structure;

- each support defines at least one fixing hole, the fairing defining at least one opening adapted to open onto the fixing hole when the fairing is assembled to the structure, the fixing hole and the openings being suitable for receiving a member fixing the fairing to the structure;

- the fairing is made from an elastomeric material;

the fairing is made from a rigid material, in particular a syntactic foam comprising a resin matrix and glass microspheres included in the matrix;

the fairing is made up of a plurality of segments assembled on the structure and aligned in a direction parallel to the axis; and

- A contact surface of the fairing on the structure comprises a reversible adhesive fixing the fairing to the structure.

The invention also relates to a submarine or submarine vessel comprising at least one mast as described above.

The invention will be better understood on reading the description which follows, given solely by way of example and made with reference to the appended drawings, among which:

- Figure 1 is a side view of an underwater vessel according to the invention;

- Figure 2 is a side view of a mast according to a first embodiment of the invention;

- Figure 3 is an exploded detail view of the mast of Figure 2;

- Figure 4 is a horizontal sectional view of the mast of Figures 2 and 3;

- Figure 5 is a partially exploded side view of a mast according to a second embodiment of the invention; and

- Figure 6 and a horizontal sectional view of the mast of Figure 5.

In Figure 1, an underwater vessel 10 is shown plunged into a body of water 12, at a shallow depth below a surface 14 of the body of water 12.

The submarine building 10 has two masts 16, extending from an upper turret 20, the masts 16 protruding from the surface 14.

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

The masts 16 comprise a fresh air tube 22, corresponding to a first embodiment shown in detail in Figures 2 to 4, and a standard mast 24, corresponding to a second embodiment shown in detail in Figures 5 and 6.

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

As shown in Figure 2, the structure 26 comprises a tube 30 defining an internal duct opening at an upper end of the tube 30, and adapted to convey air from the outside to the inside of the building 10 in order to '' powering building motors 10.

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.

The frame 34 is for example a bar having a substantially cylindrical elongated shape, integral with the tube 30 at its two ends.

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 reassembled on the structure 26 without requiring repairs or replacement.

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

The fairing 28 is shown in detail in Figures 3 and 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.

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.

The fairing 28 comprises a deformable part 42 defining an opening 44 for access to the housing 40.

In the example shown in Figures 2 to 4, the fairing 28 is made in one piece from an elastic material, for example an elastomer. The entire fairing 28 then constitutes the deformable part 42.

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

As a variant, the fairing 28 comprises several parts made from different materials, at least one of which constitutes the deformable part 42.

As shown in 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 maintains the fairing 28 on the structure 26 .

The opening 44 is able to be deformed so as to increase its transverse width e in a reversible manner and allow the passage of the frame 34 during assembly and disassembly of the fairing 28.

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

The contact surface 46 extends around the housing 40, as a cylinder portion.

The adhesive is a reversible adhesive, that is to say an adhesive exhibiting 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 attachment offered by the adhesive is of the type known by the designations “temporary bonding”, “repositionable bonding” or “non-permanent bonding”.

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 of less than 0.5 MPa.

The low peel strength of the adhesive allows the assembly of the fairing 28 to the structure 26 to remain removable, offering low resistance to the peel removal of the fairing 28 from the frame 34.

The adhesive prevents movements of the shroud in rotation around the frame 34, which are associated with shear stresses for which the adhesive exhibits a higher strength than that to peel stresses.

The fairing 28 according to the first embodiment is more resistant to impacts with drifting objects by virtue of its realization of elastomeric material, and effectively absorbs the vibrations due to the drag.

In the second embodiment, shown in detail in Figures 5 and 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 axis Z- Z '.

Two segments 50 are shown in Figure 5, one assembled on the structure and the other away from the structure.

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

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

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.

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 '.

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

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

The supports 62 are adapted to engage in the notch 56 of each segment 50 during the 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.

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

The fairing 28 then comprises fixing members 66 received in the openings 58 and the orifices 64 so as to secure the segment 50 to the structure. The fasteners 66 are for example bolts.

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.

The mast 16 according to the second embodiment comprises a fairing 28 assembled in a removable manner, since one or more of the fasteners 66 can be removed in order to dismantle one or more segments 50, which can then be reassembled as they are.

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 the damaged segments 50 only.

The realization of the fairing 28 in syntactic foam allows it to have excellent resistance to hydrostatic pressure, while maintaining a sufficiently low density.
CLAIMS

1.- 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 with respect to the structure (26) in a direction normal to the axis (Z-Z '),

characterized in that the fairing (28) is assembled in a removable manner to the structure (26).

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

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

4. A mast (16) according to any one of claims 1 to 3, wherein the structure (26) comprises a plurality of supports (62) projecting from a post (60), the fairing (28) defining a notch. (56) receiving the supports (62), the supports (62) holding the fairing (28) against the structure (26).

5.- Mast (16) according to claim 4, wherein each support (62) defines at least one fixing hole (64), the fairing (28) defining at least one opening (58) adapted to open onto the orifice. fixing (64) when the fairing (28) is assembled to the structure (26), the fixing hole (64) and the openings (58) being suitable for receiving a fixing member (66) of the fairing (28) to the structure (26).

6. A mast (16) according to any one of claims 1 to 5, wherein the fairing (28) is made from an elastomeric material.

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

8. A mast (16) according to any one of claims 1 to 7, wherein the fairing (28) consists of a plurality of segments (50) assembled on the structure (26) and aligned in a direction parallel to the axis (Z-Z ').

9. A mast (16) according to any one of claims 1 to 8, wherein a contact surface (46) of the fairing (28) on the structure (26) comprises a reversible adhesive fixing the fairing (28) to the structure (26).

10. A marine or submarine vessel (10) comprising at least one mast (16) according to any one of claims 1 to 9.