FR2890087A1 - Ship e.g. yacht, wharf structure for e.g. port, has pneumatic and/or hydraulic breakwater device with tubes drilled with orifices forming liquid or gaseous fluid projection nozzles to create currents opposed to heave propagation direction - Google Patents

Abstract

The present invention relates to a wharf structure (1) for ships (10) in short call, comprising anchoring elements (11) on the bottom of a body of water and extending vertically up to above the surface of the water, and a landing apron (12) cooperating with said anchoring elements to form a landing stage enabling the docking of said vessels and the unloading of passengers or goods, said structure comprising a breakaway device; blades (3, 4, 8, 9, 11, 12) integral with said anchoring elements between the bottom and the sea surface, and which can be implemented temporarily automatically by means of a control device to attenuate the amplitude (A) of the incident swell (5) to said structure and allow the wharf of said vessels.

Description

Temporarily self-protected wharf structure against swell

an integrated breakwater device

  The present invention relates to the field of maritime, river and / or lake constructions for the reception and service of ships of all kinds. The invention relates more particularly to a wharf structure allowing the reception of ships in short call, that is to say stopovers whose duration varies from a few minutes to a few days depending on the type of ship and their uses, particularly in areas not protected against swells.

  The wharf structure of the invention will find particular application for short-term landing of pleasure craft, passenger shuttles, cruise ships or regattas or coasters, whose size is a brake at their temporary reception in the ports.

  The reception of these large ships currently poses several types of problems. First, the majority of ports, especially on the Mediterranean coasts, are in a situation of waterlogging by which they are unable to accommodate new boats for lack of available places, whether for short or long length of stopovers.

  However, the yachting market (units of more than 24 m requiring a permanent crew) has been experiencing a considerable increase in recent years, which is reflected in significant needs for places and services, particularly on the Côte d'Azur and in France. the Caribbean and the limitation to accommodate such vessels is tantamount to very substantial financial losses for the ports of the coastal cities where the wealthy owners of such vessels wish to stay during their holidays or for event events held there.

  On the basis of this observation, several solutions are technically feasible to create places for these pleasure craft units.

  We can first try to free up places in existing ports (in areas with sufficient water depth, ie 4 to 5 m minimum) by moving small boats to shore or port lagoons. However, this solution is not likely to satisfy the owners of these small boats that have often long waited to get a ring and pay dearly the annual rental of it.

  Another solution is for example to enlarge the ports by building new basins protected from the swell by dikes. Port expansion could also be considered without creating additional protection structures by digging new docks further inland, behind existing basins, provided that land permits permit this, which is rarely the case. These two solutions are however almost impossible to implement, at least in France. Indeed, the littoral law limits very seriously the projects of creation or extension of ports. In addition, many laws, European Directives and International Convention protect underwater flora and fauna. Thus in the Mediterranean sea in particular, posidonia meadows are very present in front of the ports and it is forbidden to destroy them or to move them. As a result it is often impossible to create new dikes to extend the ports.

  The lack of spaces in the ports becomes crucial because it hampers the development of nautical industries which nevertheless is a booming market.

  In some ports, the traffic of passenger motorboats also causes, in addition to the problem of space, nuisance to other users including, inter alia, agitation caused by bow waves, noise and odor, etc. It would also be interesting in some cases to move these passenger shuttles from existing ports to free up spaces for medium and / or pleasure boats.

  The object of the present invention is to propose a solution to the problems posed for the reception of large vessels in short stopover.

  Another object of the invention is to provide a structure which makes it possible to carry out, temporarily or permanently, an extension of the current ports to allow the reception of large ships, including pleasure craft, passenger shuttles or coasters, and which provides satisfactory protection against waves to allow the landing of these vessels and the landing of passengers or goods.

  Another object of the invention is to create a possibility of berthing ships for short stopovers, on new sites on which it is not possible or not profitable to create a traditional port.

  Another object of the invention is to provide a said extension structure of the current ports which has no impact on the underwater flora and fauna and therefore does not contravene the texts protecting them.

  These various objects are achieved according to the present invention by means of a wharf structure comprising: anchoring elements integral or resting at a lower end on the bottom of a navigable body of water and extending vertically up to at an upper end above the surface of the water, and - an unloading apron cooperating with said anchoring elements at their said upper end to form a substantially horizontal landing point allowing the docking of said vessels and the unloading of passengers or goods in a secure manner.

  This wharf structure is characterized according to the invention in that it comprises at least one integrated breakwater device and secured to said anchoring elements between the bottom and the surface of the water, said breakwater device can be implemented temporarily automatically via a control device to reduce the amplitude of the swell incident to said structure and allow the wharf of said vessels.

  Such a wharf structure, anchored on the seabed and equipped with a breakwater advantageously allows to create a jetty pier outside the existing ports or on new landing sites on which it is not feasible or unprofitable to create a traditional port, to receive ships in short stopover and do not need to be continuously protected against swells. The breakwater makes it possible to generate currents opposed to the swell between the anchoring elements under the deck of the wharf structure, currents that dampen the swell incident to the structure. The breakwater can be implemented temporarily via said control device, automatically, so as to mitigate the swell to allow docking ships when said swell makes the maneuver complex and dangerous or when it is too strong in relation to the maintenance of moored vessels.

  Depending on the type of use, the vessels may be moored on an edge parallel to the wharf structure, or, in the case of reception of pleasure craft units in the context of temporary events events, in heel next to others.

  Another advantage of the wharf structure of the invention is that it has virtually no influence and therefore no impact on the seabed and the flora that can develop there such that the meadows of posidonia and cymodocea.

  According to a first preferred embodiment of the invention, said breakwater device is of the pneumatic and / or hydraulic type and comprises means for projecting a fluid attached to said anchoring elements, preferably close to their location. said lower end and / or near their said upper end and below the surface of the water, to generate currents and turbulence intersecting and / or opposed to the direction of said incident swell to the pontoon structure.

  Said projection means of the breakwater can be fixed to the anchoring elements of the boom, the side under the swell, in the lower part but above the possible seagrass and / or preferably attached to said anchoring elements on the side opposite to the swell (protected side), closer to the surface and, if necessary, to several levels of projection.

  According to another characteristic of the invention, said projection means comprise at least one perforated tube extending substantially parallel to the bottom of the water plane above the level thereof and being connected to a feed device. fluid actuated by said controller.

  Thus, only the deck of the wharf structure is apparent on the surface of the water because the components of the breakwater are fully immersed and integrated under the deck and therefore virtually invisible. This avoids disfiguring the coastal landscape by unsightly and imposing constructions on the water.

  In another preferred embodiment, said breakwater device may comprise mechanical stirring means such as beaters or propellers, integral with said anchoring elements and actuated by said control device. Of course, other systems are also conceivable to produce the flow of water against the swell.

  In the various embodiments of the invention, said fluid supply device of said projection means is constituted by a compressor and / or a pump actuated by said control device. Said compressor and / or said pump may advantageously be placed in a technical room on the ground and connected by submarine pipes appropriate to said projection means of the breakwater.

  In a preferred embodiment, said control device comprises electronic control means of said fluid supply device of said projection means and said mechanical stirring means, such as for example a computer station or a control automaton. It also preferably comprises remote control means, in particular by radiofrequency or other similar means, said remote control means allowing for example the implementation of said breakwater device from a ship approaching said structure to land there or since an observation post of a captaincy for example.

  Thus, in the case of use of the pontoon structure for passenger boats, it is conceivable that it is the ship's captain who will manually activate the action of the breakwater using a radio remote control , during his approach phase, before docking and mooring his boat. In the case of mooring medium and / or large pleasure vessels it is rather the harbor master's office that will trigger the action of the breakwater.

  In an advantageous embodiment of the invention, the wharf structure also comprises means for measuring the amplitude of the swell connected to said control device, so as to automatically trigger the implementation of the breakwater device according to the average amplitude of the swell measured during a given time interval. Said measuring means may in particular be pressure sensors, positioned and anchored on the bottom of the water body, at a determined distance from said structure.

  This control mode of the breakwater device is ideally suited for use in the docking of pleasure craft units, for which the triggering can be automated from a certain threshold such as the peak amplitude to hollowness of the swell measured thanks to said pressure sensors located on the bottom outside the structure.

  In this embodiment, said control device preferably further comprises regulating means connected to said feeding device of said projection means and to said propulsion means so as to automatically adjust the operating power of the breakwater according to the magnitude of the incident swell measured by said measuring means.

  Thus, it is possible to automatically adapt the power, and therefore the energy consumed by the breakwater device, to the characteristics of the incident agitation (amplitude, period and direction). The characteristics of the swell can be measured continuously by said sensors connected to said computer station or said controller of the control means of the device which analyzes the data in real time and automatically controls the compressor and / or the pump of the breakwater to optimize the power of the latter at each moment to the characteristics of the incident agitation.

  According to another advantageous characteristic of the invention, said means for projecting the breakwater device are, if appropriate, rotatable relative to said anchoring elements by means of motorized rotary drive means actuated by said device. control. It is thus possible to optimize the direction of the currents in the most appropriate directions to attenuate the waves incident on the structure.

  In order to ensure a good holding of the deck over the water and a good mechanical resistance to the waves and the forces applied by the moored ships, said anchoring elements of the pontoon structure are preferably constituted by piles embedded in the seabed and connected in pairs by trimmers to form gantries supporting said deck. These piles may be preferably metal and / or concrete based on the depths of construction of the wharf structures and their length, and uses thereof.

  In some cases, particularly for poorly exposed sites and / or smaller vessels, the wharf may be of reduced width and based on a single line of piles. In other cases, if the flow of passengers or goods requires to create a wider wharf, the deck of the structure according to the invention may be wider and maintained on several lines of piles.

  A second aspect of the present invention is to provide a method of protecting against waves a wharf structure comprising anchoring means on the bottom of a body of water maintaining a fixed deck or floating above the surface of the water. According to this method, secant currents and / or those which are opposite to the direction of the wave incident to said structure are generated temporarily, under said wharf structure, by means of a breakwater device integral with said wad elements. anchoring of the structure, and preferably pneumatic and / or hydraulic.

  The protection method according to the invention can thus be applied to existing wharf structures but poorly protected from the swell, which is equipped with a pneumatic and / or hydraulic breakwater device.

  According to a first preferred characteristic of the process of the invention, currents attenuating the incident swell are generated by diffusion of a curtain of bubbles and / or by diffusion of water jets formed by means of projection means of the broken device. -lames.

  These generated currents make it possible to "break" the swell and to reduce its average amplitude at the wharf structure.

  In a particular embodiment, it is particularly advantageous to automate the wave protection method of the invention. For this purpose: the amplitude of the incident swell is measured at a determined distance from the temporary wharf structure by means of said measurement means and the implementation of said breakwater device is carried out automatic when the measured amplitude exceeds a specified value; the power of the breakwater device and the currents generated by it are adjusted according to the amplitude of the measured swell; and finally - if necessary, the orientation of said projection means is varied during operation of said breakwater device.

  Protection of the wharf structure is thus achieved automatically via the breakwater device whose operation is adjusted in real time to the swell conditions in the presence of the area of the protected wharf structure.

  Other features of the invention will emerge on reading the detailed description of the invention which follows, with reference to the appended figures in which: FIG. 1 represents a transverse section of a wharf structure according to FIG. the invention in a preferred embodiment which shows said structure protected by a breakwater fixed and integrated under the structure itself; - Figure 2 is a perspective view of the pontoon structure of Figure 1; FIG. 3 represents a plan view of an example of the implementation of a wharf structure according to the invention outside a protective dyke of an existing port; - Figure 4 shows a plan view of a second example of implementation of a wharf structure according to the invention for application to event events with temporary docking vessels of large or medium pleasure.

  The detailed description which follows, with reference to FIGS. 1 to 4, is given for an exemplary embodiment of a wharf structure self-protected against the swell according to the invention in a maritime application. However, such a structure can also be made and used for river and / or lake applications without particular arrangements or modifications compared with the description given below.

  Figures 1 and 2 show a pontoon structure 1 according to the present invention in a preferred embodiment. It comprises a framework based on piles 11 forming anchoring elements of the structure on the bottom 21 of the sea 2, and on the upper end of which an upper deck 12 is fixed to form a pier pierstop on piles. The piles 11 are embedded at their lower end in the submarine substratum and extend to the upper end above the sea surface. The deck 12 is formed of trimmers connecting the piles 11 two by two. their said upper ends and supporting longitudinal concrete beams on which a decking of wooden slats, PVC slabs, composites or other (not shown) is laid to achieve a landing landing anti-slip.

  Underwater 2, the pontoon structure 1 comprises a pneumatic and / or hydraulic breaking device comprising a first tube 3 fixed near the bottom 21 to the line of piles 11 under the swell 5 and a second tube 4 fixed above under the surface of the water on the other line of piles. The tubes 3, 4 are pierced along their length of orifices constituting nozzles for projecting a liquid or gaseous fluid to create secant currents and / or opposed to the direction of propagation D of an incident wave 5 to the structure of wharf 1 by diffusion of a curtain of bubbles 6 and / or jets of water 7 under pressure.

  For this purpose, the tubes 3, 4 are respectively connected to a sound-proof compressor and a pump which each supply air and seawater under pressure when the breakwater device is implemented. Preferably, said compressor will be installed on the ground in a technical room 8 and connected by appropriate pipes 9 to the perforated tube 3. The feed pump of the hydraulic breakwater may be, according to the sites, installed directly on the wharf or, like the compressor, in a technical room 8 installed on the ground, in which case the pumping may be carried out directly in the sea 2 or in a terrestrial tank, preferably located above the body of water, and the water propelled to the tube 4 by appropriate pipes 9.

  The projection tube 3 of the pneumatic breakwater thus makes it possible to create a curtain of rising air bubbles along the line of piles 11 beneath the incident swell 5. These air bubbles then generate a current C1 that allows damping said swell. The hydraulic breakwater generates a C2 current by projecting water jets 7 in a secant direction and / or opposite to that of propagation D of the swell 5 by means of the projection tube 4.

  The embodiment shown in Figures 1 and 2 has a pontoon structure 1 provided with a double pneumatic breakwater 3 and hydraulic 4. However, the invention is not limited to this particular embodiment. In fact, depending on the sites of implantation of wharf structures according to the invention provide a solely pneumatic or solely hydraulic breakwater device or as in the example in a combination of both in order to better adjust the capabilities of said breakwater according to the agitation of the water.

  It is also possible in certain cases to provide other additional or autonomous means of agitation fixed on the piles 11, such as propellers or mechanical blades to increase the turbulences and the currents at the base of the structure 1 in order to attenuate the effects of the swell 5.

  The breakwater device of the wharf structure 1 is not intended to operate continuously because it is not a question of protecting the body of water permanently, but only when a vessel 10 wishes to dock or is docked. to the structure and if the weather conditions are not good. Its operation can be triggered automatically via a control device located on the ground in the technical room 8.

  This control device comprises electronic control means of the breakwater device and more particularly of the compressor and of the supply pump for the projection tubes 3, 4. These control means preferably consist of a computer station or an automatic controller. programmed commands to trigger breakwater operation following a control command.

  To improve the functionality and the flexibility of implementation of the breakwater device, the control device comprises radio frequency remote communication means. These remote communication means allow in particular the commander of a ship 10 to manually operate (if it sees fit) the breakwater device using a radio control, during its approach phase, before docking and mooring his boat to the wharf structure.

  In an alternative embodiment shown diagrammatically in FIG. 3, the operation of the breakwater device of the wharf structure 1 is controlled entirely automatically by means of pressure sensors 11 implanted on the bottom of the sea 21 at a distance of the wharf structure 1. These sensors 11, which are connected by connections 12 buried in the seabed and connected to the control device, make it possible to measure continuously the characteristics of the incident swell 5, and more particularly the variations of amplitude peak to hollow A of this swell.

  Thus, when this amplitude A exceeds a threshold value recorded in the control device (computer station or PLC), the latter interprets this overshoot as a control command and actuates the breakwater device to attenuate the amplitude of the swell 5 to close to the wharf structure 1. As soon as the amplitude of the swell detected by the pressure sensors 11 decreases and returns to a value below the limit threshold, the control device then stops the breakwater device.

  This embodiment is particularly interesting because it allows to better control the energy consumption required for the implementation of the breakwater, energy consumption which is an essential parameter of the operating cost of the wharf structure 1 of the invention.

  The number of pressure sensors 11 and the installation distance of these are determined according to the characteristics of each installation site of the wharf structure 1. However, their number will generally vary between 2 and 5 and their distance. The installation will be between 100 and 400 m off the wharf structure 1.

  In an alternative embodiment not shown, the sensors 11 can be replaced by a digital wave measurement acquisition system integrated into the control device.

  The measurement and the real-time analysis of the characteristics of the incident wave 5 by means of said sensors 11 also make it possible to automatically adjust, via said control device, the power of the compressor and / or the feed pump. projection tubes 3, 4 of the breakwater device to optimize at each instant the power consumed by the breakwater according to the characteristics of the incident agitation 5. To enable this power adjustment, the breakwater device will comprise or will control appropriate regulation means connected to the compressor and / or the feed pump of the projection tubes 3, 4.

  The wharf structure 1 according to the invention, protected by its pneumatic and / or hydraulic breakwater device makes it possible to create spaces outside the ports, for ships in short stopover, which do not need to be continuously protected against waves such as passenger shuttles and pleasure craft. It also has very little physical resistance against swell in the event of a storm, which limits the risk of damage to the structure 1. Only the upper deck is fuse and can be damaged during a storm of occurrence rare.

  In addition, such a pile structure has practically no influence and therefore no impact on the seabed and therefore allows full compliance with the laws and texts of protection of the coastline and the marine fauna and flora. .

  Of course, the mechanical characteristics of the wharf structure, in particular those of the piles 11 will have to be calculated and chosen according to the topography and the geotechnical characteristics of the site of implantation of the structure, in particular of the nature of the bottom and the depth of water, as well as dimensions of the structure itself. This calculation of the mechanical characteristics of elements of the structure 1 can be carried out according to standardized procedures and using structural modeling software well known in the field of marine and river civil engineering For example, for a structure of structure 1 1 of a length of 80 m and a width of 3 m, intended to simultaneously accommodate a dozen vessels with an average size of between 20 and 30 m, it is appropriate to use theoretically metal piles 11 of a diameter at least equal to 610 mm and a thickness of at least 19 mm, arranged in a regular mesh of 2, 20 mx 8, 00 m. These piles must be embedded in the seabed 21 to a depth calculated according to the regulations and recommendations in force and filled with concrete over a height of 1 m to 1.50 m at the head. Said piles must then be connected two by two by "T" shaped members of reinforced concrete of 0.8 m2 of section, able to receive longitudinal beams of reinforced concrete resting with neoprene supports on the headers, the beams then being covered transverse wooden laths assembled on an aluminum metal frame to form the upper deck of the structure 1. The 30-ton bollards are then fixed on the deck 12 to the right of the piles 11 to allow docking of the dolls docked. It is also possible to provide water and electricity terminals on the upper deck 12 to allow the connection of the berthed vessels.

  Under such conditions, calculations have shown that the wharf structure 1 satisfies all the critical stress conditions for the construction of aquatic structures.

  FIGS. 3 and 4 show diagrammatically and in plan two preferred applications for which landing gear structures 1 conforming to that of the present invention are particularly advantageous and make it possible to overcome the problems of accommodating large vessels in stopping mode. short haul in existing ports or to create a temporarily self-protected pier against waves on new sites for which it is not feasible to carry out a traditional port for environmental and / or economic reasons.

  FIG. 3 represents an example of implementation of a wharf structure 1 constituting a jetty pier for the operation of passenger shuttles 10. Boom 1 is built outside the basin of an existing port 13 Protected from the swell by a dike 14. It is connected to said dike by a connecting bridge 15 allowing the pedestrian path between the cap 141 of the dike and the boom. This boom is temporarily protected against the swell by a hydraulic and / or pneumatic breakwater device as described above whose actuation is controlled by pressure sensors 11 positioned regularly off the boom 1 and connected to the control device the breakwater installed on the dike 14 in a technical room 8 also containing a compressor and / or a pump for supplying air and seawater to the breakwater device of the boom 1 and the control device of the breeze -lames.

  FIG. 4 represents a second example of implementation of a wharf structure 1 according to the invention for the reception, for example during event events or summer periods, of pleasure craft 10 such as yachts or large sailboats. As in the example of Figure 3, the wharf structure 1 is constructed outside the basin of an existing port 13 protected from the swell by a dike 14 and connected by a connecting bridge 15 to the dike. The boats 10 are not moored lengthwise, but in heel, at the pier 1 between the latter and the dam, protected from the incident swell by the breakwater device of the boom operated by sensors 11 positioned off .

  Depending on the swell conditions (if necessary depending on the site), the connecting bridge 15 to the dike may itself be constituted by a boom equipped with a breakwater, thus completing the protection and allowing the berthing of vessels 16 smaller. A partial return 17 at the other end of the main boom 1 makes it possible to complete the protection. Finally, in the access pass, it can close the protection against the dam 14 by extending (dotted in Figure 4) the pneumatic and / or hydraulic breakwater of the main boom 1 on anchors (piles, anchors to screws, etc.) implanted and leveled under water, so as to allow access to the vessels. In this case, the maximum draft of the vessels and the "pilot's foot" must be taken into account in order to choose whether or not to extend the breakwater.

Claims (13)

claims   1 Spillway structure (1), in particular for short stop ships (10), of the type comprising anchoring elements (11) integral or resting by a lower end on the bottom (21) of a plane of water (2) and extending vertically to an upper end above the surface of the water, and a landing apron (12) cooperating with said anchoring elements (11) at their said upper end for forming a substantially horizontal landing stage enabling the docking of said vessels and the unloading of passengers or cargo in a secure manner, characterized in that said structure comprises at least one breakwater device (3, 4, 8, 9, 11, 12 ) integrated and secured to said anchoring elements (11) between the bottom and the surface of the water (2), said breakwater device being able to be temporarily activated automatically by means of a control device to attenuate the amplitude e of the incident swell (5) to said structure and allow the docking of said vessels.   2 pontoon structure according to claim 1, characterized in that said breakwater device comprises means for projecting (3, 4) a fluid attached to said anchoring elements (11), preferably close to their said lower end and / or near their said upper end and under the surface of the water, to generate currents (C1, C2) and turbulence intersecting and / or opposed to the direction of propagation (D) of said incident swell to the wharf structure.   3 pontoon structure according to one of claims 2, characterized in that said projection means comprise at least one perforated tube (3, 4) extending substantially parallel to the bottom of the water level above the level of it and being connected to a fluid supply device actuated by said control device.   4 Structure according to claim 3, characterized in that said breakwater device comprises mechanical stirring means such as beaters or propellers, integral with said anchoring elements and actuated by said control device.     A pontoon structure according to one of claims 3 or 4, characterized in that said fluid supply device of said projection means (3, 4) is constituted by a compressor and / or a pump actuated by said control device.   6 pontoon structure according to one of claims 3 to 5, characterized in that said control device comprises electronic control means of said fluid supply device of said projection means (3, 4) and said mechanical means of agitation.   7 - Bridge structure according to one of claims 1 to 6, characterized in that said control device comprises remote control means, in particular by radio frequency or other similar means, said remote control means allowing the implementation of said blade breaker device from a ship approaching said structure to abut.   8 pontoon structure according to one of claims 1 to 7, characterized in that it also comprises means (11, 12) for measuring the amplitude (A) of the wave (5) connected to said device control, so as to automatically trigger the implementation of the breakwater device according to the average amplitude of the swell measured during a determined time interval.   9 pontoon structure according to claim 8, characterized in that said measuring means are pressure sensors (11), positioned on the bottom of the water, at a predetermined distance from said structure.     A pontoon structure according to claim 8 or 9, characterized in that said control device further comprises regulating means connected to said feeding device of said projection means so as to automatically adjust the operating power of the breakwater as a function of the amplitude (A) of the incident swell (5) measured by said measuring means.   11 pontoon structure according to one of claims 2 to 10, characterized in that said projection means (3, 4) of the breakwater device are rotatable relative to said anchoring elements via means motorized rotational drives actuated by said control device.   12 pontoon structure according to one of the preceding claims, characterized in that said anchoring elements are piles (11) embedded in the seabed and connected in pairs by trimmers to form gantries supporting said apron .   13 A method of protecting against waves a wharf structure (1) comprising anchoring means (11) on the bottom (21) of the sea (2) supporting an apron (12) above the surface of the the sea, characterized in that transient currents (C1, C2) and / or opposed to the direction of propagation (D) of the incident wave (5) are temporarily generated, in line with said structure. to said structure via a pneumatic and / or hydraulic breakwater device (3, 4, 8, 9, 11, 12).   14 Method according to claim 13, characterized in that one generates said currents (C1, C2) attenuating the incident swell by diffusion of a curtain of bubbles (6) and / or by diffusion of jets (7) of water formed by means of projection means (3, 4) of the breakwater device.   Method according to one of Claims 13 to 14, characterized in that the amplitude (A) of the incident swell (5) is measured at a determined distance from the temporary wharf structure via means (11, 12) and the implementation of said breakwater device is started automatically when the measured amplitude exceeds a determined value.   Method according to claim 15, characterized in that the power of the breakwater device and the currents generated thereby are adjusted according to the amplitude of the measured swell.   Method according to one of claims 14 to 16, characterized in that the orientation of said projection means (3, 4) is varied during operation of said breakwater device.