AU2020364982A1 - Towed underwater device and system for handling the underwater device - Google Patents

Abstract

The invention relates to an underwater device (12) which is intended to be towed by a surface vessel (10) and a handling system (20) which is intended to be installed on the surface vessel (10) and which allows the underwater device (12) to be stored and deployed, the underwater device (12) comprising a traction cable (18), a flexible elongate member (16) and a towed member (14) which is located between the flexible elongate member (16) and the traction cable (18) during use of the underwater device (12), the handling system (20) comprising a first winch (24) for storing and deploying the traction cable (18) and the towed member (14) and a second winch (26) for storing and deploying the flexible elongate member (16). The underwater device (12) comprises an arm (30) which is articulated to the towed member (14) and to the flexible elongate member (16), in a first deployed position, the arm (30) being aligned with the flexible elongate member (16) allowing the first winch (24) to pull the entire underwater device (12), in a second position, the arm (30) being out of alignment with the flexible elongate member (16) allowing the alignment of the flexible elongate member (16) with the second winch (26).

Description

DESCRIPTION Title of the invention: Towed underwater device and system for handling the underwater device

[0001]The present invention relates to an underwater device intended to be towed by a surface ship and a handling system intended to be installed on the surface ship and used for storing and deploying the underwater device. The invention is of particular utility in the field of underwater devices of the active sonar type comprising a cable towing a towed body incorporating a transmission antenna known as a transmission array. The towed body is sometimes referred to as a "tow fish" on account of its shape. A linear reception antenna known as a reception array, forming a flexible elongate body, is towed behind the tow fish. The linear reception array is sometimes referred to as a "streamer", likewise on account of its shape. The towed body may be a body of volume suspended from the tow cable or else may be of elongate shape along a longitudinal axis and incorporate a linear transmission array comprising transducers distributed along the longitudinal axis.

[0002] The handling of such underwater devices is tricky. More specifically, outside of periods of use, the underwater device is stored on a deck of the surface ship, generally a stern deck. The launch and recovery of the underwater device requires operators to be present on the stern deck of the surface ship. The operators have to handle heavy loads, and this may be dangerous, particularly in a developed sea.

[0003] The tow cable generally comprises a core formed of electrical and/or optical conductors for transmitting power and information between sonar equipment situated onboard the ship and the antennas of the array. The core of the cable (or "core cable") is generally covered with a strand of metal wires that give the cable its mechanical strength. The towed body is generally massive. It may be fitted with rudders to provide its hydrodynamic stability. The linear reception array may extend over a length of the order of around hundred meters in order to detect soundwaves travelling through the water at low frequency. These may be echoes of soundwaves emitted by the transmission array when the sonar is operating in active mode. The sonar may also operate in passive mode without the transmission of soundwaves.

[0004] In patent application WO 2018/065385 Al filed in the name of the Applicant Company, a single winch is used for handling the tow cable and the reception array.

The tow cable and the reception array are secured to one another. Upon launch, the towed body is attached and connected at the junction between the tow cable and the reception array. Such an arrangement of the tow cable and of the reception array on one and the same winch does present certain problems. In particular, the winch needs to be suited to the greatest radius of curvature permitted by the tow cable and by the reception array. That may lead to the drum of the winch being significantly oversized. In addition, it may be beneficial to handle the tow cable and the reception array separately, something that a single winch is unable to permit.

[0005] The invention anticipates the use of two distinct winches, one for the tow cable and the other for the reception array. The objective of the invention is to facilitate the maneuvers of launching and recovering the various elements of the towed underwater device.

[0006] To that end, the invention proposes an underwater device intended to be towed by a surface ship and handling system intended to be installed on the surface ship and used for storing and deploying the underwater device, the underwater device comprising a tow cable, a towed body and a flexible elongate body, the towed body being situated between the flexible elongate body and the tow cable during use of the underwater device, the handling system comprising two distinct winches, the first winch being used for storing and deploying the tow cable and the towed body, the second winch being used for storing and deploying the flexible elongate body. According to the invention, the underwater device comprises an attachment mechanism for attaching the flexible elongate body to the second winch and an arm articulated at a first of its ends to the towed body and at a second of its ends, removably, to the flexible elongate body, in a deployed first position, the arm being aligned with the flexible elongate body allowing the first winch to tow the entire underwater device, in a second position, the arm being unaligned with respect to the flexible elongate body allowing the flexible elongate body to be aligned with the second winch.

[0007] Advantageously, the articulation of the arm to the flexible elongate body is disconnectable.

[0008] The underwater device may comprise an electrical and/or optical connection between the towed body and the flexible elongate body. The electrical and/or optical connection is advantageously disconnectable.

[0009] Advantageously, the arm comprises, at its second end, a fairlead for guiding the flexible elongate body. The flexible elongate body then comprises a stopper configured to come into abutment against the fairlead, the stopper being positioned at one end of the flexible elongate body, the end articulated to the arm.

[0010] The handling system may comprise an actuator configured to cause the arm to switch between its two positions: the position aligned with the flexible elongate body and the position unaligned with respect to the flexible elongate body.

[0011] The actuator may be the second winch or distinct from the second winch.

[0012] The handling system may comprise two gates that can be maneuvered separately from one another, a first of the two gates being positioned between the first winch and the sea, a second of the two gates being positioned between the second winch and the sea. When the arm is in the second position, the handling system is configured so that the first of the two gates can remain closed.

[0013] Another subject of the invention is a method for implementing the underwater device and the handling system allowing the launching of the device; in order to launch the underwater device, the method consists in performing the following sequence of operations: a. paying out from the second winch in order to launch the flexible elongate body, b. connecting the flexible elongate body to the second end of the arm in the unaligned position, c. bringing the arm into the aligned position, d. paying out from the first winch.

[0014] In a first variant, the method consists, between operations c and d, in: e. detaching the flexible elongate body from the second winch by maneuvering the attachment mechanism.

[0015] In a second variant, the method consists, between operations b and c, in: f. operating the actuator to take up the load of the flexible elongate body on the arm, g. detaching the flexible elongate body from the second winch by maneuvering the attachment mechanism, operation c being performed by maneuvering the actuator.

[0016] The invention will be better understood and further advantages will become apparent from reading the detailed description of an embodiment given by way of example, the description being illustrated by the attached drawing in which:

[0017]figure 1 schematically depicts a ship towing an active sonar;

[0018]figure 2 depicts the ship of figure 1 the sonar of which is in the process of being launched or brought back up;

[0019]figures 3, 4, 5, 6, 7 and 8 illustrate the launching and the bringing back up of a reception array of the sonar depicted in figures 1 and 2;

[0020]figures 9, 10 and 11 illustrate a first variant of a system for handing the sonar depicted in figures 1 and 2;

[0021]figures 12, 13, 14, 15, 16 and 17 illustrate a second variant of a system for handling the sonar depicted in figures 1 and 2.

[0022] For the sake of clarity, throughout the various figures, the same elements will bear the same references.

[0023] The invention is described in connection with the towing of an active sonar by a surface ship. Of course the invention may be implemented for any type of towed underwater device.

[0024] Figure 1 depicts a ship 10 towing an active sonar 12 comprising a towed body 14 incorporating an acoustic transmission array and a flexible elongate body 16 forming an acoustic reception array. Hereinafter, the towed body will be referred to as a tow fish 14 and the flexible elongate body will be referred to as a streamer 16. The sonar 12 also comprises a cable 18 for towing the tow fish 14 and the streamer 16. The cable 18 also carries signals and power between the ship 10, the tow fish 14 and the streamer 16.

[0025] The tow fish 14 and the streamer 16 are mechanically anchored and electrically and/or optically connected to the cable 18 in an appropriate way. Conventionally, the streamer 16 is formed of a linear array of tubular shape identical to those found in passive sonars, hence its name streamer, while the transmission array is incorporated into a structure of volume forming the towed body 14 and having a shape like that of a fish. The streamer 16 is anchored to the tow fish 14 which is itself anchored to the end of the cable 18. During an underwater acoustic mission in active mode, the array of the tow fish 14 transmits soundwaves into the water and the reception array of the streamer 16 picks up any echoes bouncing off targets on which the soundwaves originating from the transmission array are reflected.

[0026] A handling device 20 is placed on a stern deck 22 of the ship 10. The handling device 20 comprises two winches 24 and 26. The winch 24 is used for storing and paying out the tow cable 18 and the tow fish 14. The winch 26 is used for storing and paying out the streamer 16. When the active sonar 12 is in the deployed position as depicted in figure 1, only the winch 24 is in operation. The winch 24 tows the entire sonar 12. More specifically, the cable 18 tows the tow fish 14 and the streamer 16 is attached behind the tow fish 14.

[0027] In figure 1, the winch 24 is situated on the portside of the ship 10 and the winch 26 on the starboard side. Other configurations are also possible, with the winch 24 on the starboard side and the winch 26 on the portside, winch 24 above or below the winch 26. More generally, the two winches 24 and 26 are offset relative to one other.

[0028] The sonar 12 comprises an arm 30 articulated at one of its ends 32 to the tow fish 14 and at its second end 34 to the streamer 16. In figure 1, when the active sonar 12 is in the deployed position, the arm 30 is aligned with the streamer 16. More specifically, the arm 30 and the streamer 16 both extend substantially along the same axis 36. When the ship 10 is sailing in a straight line, the axis 36 is substantially parallel to the line of travel of the ship. In practice, the forces of drag experienced by the streamer 16 orient the arm 30 and the streamer 16 naturally in the water along the axis 36 which may fluctuate notably according to variations in the heading followed by the ship 10 and according to the weather conditions.

[0029] Figure 2 depicts the ship of figure 1 the sonar 12 of which is in the process of being launched or brought back up. More specifically, the tow fish 14 is placed on the deck 22, possibly in a cradle designed to hold it. The winch 24 is stationary. The cable 18 is almost completely wound on the winch 24. The arm 30 is unaligned with respect to the streamer 16 allowing the streamer 16 to be aligned with the winch 26. This unaligned position of the arm 30 is dependent on various dimensional parameters of the handling device 20, notably the length of the arm 30, the relative position of the tow fish 14 and of the winch 24, the distance separating the two winches 24 and 26 and the relative position thereof.

[0030] To ensure good alignment between the arm 30 and the streamer 16, at the end 32, the articulation between the tow fish 14 and the arm 30 is advantageously of the pinned ball joint, or ball joint type, which is to say having at least two degrees of freedom in rotation about axes perpendicular to the axis 36. Likewise, at the end 34, the articulation between the arm 30 and the streamer 16 advantageously has at least one degree of freedom to rotate about an axis that allows the streamer 16 to be aligned with the winch 26. The streamer 16 advantageously maintains a degree of freedom to rotate about the axis 36. This degree of freedom may be provided either at the end 32 by means of a ball joint connection or at the end 34 by means of a pinned ball joint connection. It is also possible for this degree of freedom to be situated both at the end 32 and at the end 34, thereby making it easier to align the streamer 16 with the winch 26.

[0031] In the absence of an arm 30, the operator tasked with handling the sonar 12 in order to launch it and bring it back onboard the ship 10 has to operate behind the tow fish 14 to attach the streamer 16 when launching and to detach it when bringing the sonar 12 back up. This maneuver on the part of the operator is performed in a position that is uncomfortable because the operator is impeded by the shape of the tow fish 14. In addition, this maneuver is performed very close to the water and may be dangerous, particularly in a developed sea. The presence of the arm 30 allows the operator tasked with coupling the streamer 16 to the tow fish 14 not to have to take up a position behind the tow fish 14 in order to perform the coupling.

[0032] It is possible to improve operator safety still further by means of a system of gates isolating the deck 22 from the sea.

[0033] Figure 3 depicts the stern of the ship 10 during the launching of the streamer 16. The handling system may comprise two gates 38 and 40 isolating the winches 24 and 26 and the tow fish 14 from the sea when the gates are closed. More specifically, the gate 38 is positioned between the winch 26 and the sea. The gate 40 is positioned between the winch 24 and the sea. The two gates 38 and 40 can be maneuvered independently of one another. In the variant depicted, the gate 40 has a larger surface area than the gate 38. Specifically, when the gate 40 is open it needs to allow the tow fish 14 through whereas the gate 38 has to allow the streamer 16 through, which has a cross section far smaller than that of the tow fish 14, the cross sections being defined perpendicular to the axis 36. Alternatively, the two gates 38 and 40 may have equal surface areas. The gate 40 could even have a smaller surface area than the gate 38.

[0034] In figure 3, the gate 40 is closed. The tow fish 14 is positioned on the deck 22. The tow fish 14 is protected from the sea. The gate 38 is open and the streamer 16 is partially in the water. The streamer 16 is partially wound onto the winch 26 and partially in the water astern of the ship 10. The gates 38 and 40 may be pivoting gates as depicted in figure 3. So long as the arm 30 is in the unaligned position, the gate 40 may remain closed. Any type of gate opening may be implemented in the context of the invention: the gates may for example be sliding gates, folding gates or rollup gates. It is advantageous to provide two distinct gates 38 and 40 allowing either the one or the other to be opened. More specifically, in the configuration of figure 3, only the gate 38 is open. In the configuration of figure 1 in which the arm 30 and the streamer 16 are aligned, the gate 40 needs to remain open and it is possible to reclose the gate 38. Alternatively, to simplify the handling system, it is possible to provide just one gate, for example a sliding gate, that is opened partially in the configuration of figure 3 and that is opened fully in the configuration of figure 1.

[0035] The handling system may comprise a tongue 42 on which the streamer 16 rests when the gate 38 is open. More specifically, the tongue 42 is capable of translational movement with respect to the deck 22 along an axis of an orientation similar to the direction adopted by the streamer 16 as it exits the ship 10 before trailing in the water. The tongue 42 is able to support the streamer 16 before it reaches the water so that it does not enter the water at too steep an angle when carried along by its self-weight alone. Once the streamer 16 has reached the water, a drag force applied to the streamer 16 has a tendency to limit its inclination. In the retracted position, the tongue 42 may be hidden by the gate 38. In the deployed position, the tongue 42 may extend beyond the volume occupied by the gate 38 when the gate is closed. The tongue 42 is therefore deployed only when the gate 38 is open.

[0036] The handling system may comprise, at the end 34 of the arm 30, a fairlead 44. The fairlead 44 guides the streamer 16 when the winch 26 is maneuvering the streamer 16 either in order to launch it or in order to bring it back up. The fairlead 44 guides the streamer 16 along the axis 36. The dimensions of the cross section of the streamer 16 perpendicular to the axis 36 are smaller than the dimensions of the internal cross section of the fairlead 44. The fairlead 44 leaves the streamer free to rotate about the axis 36. A pivot connection is therefore sufficient to connect the fairlead 44 to the arm 30 at the end 34 thereof.

[0037] In the variant depicted, the fairlead 44 has a cross section that is closed around the streamer 16. Alternatively, the cross section of the fairlead 44 may be open, so that the streamer 16 can be positioned in the fairlead 44 after the streamer 16 has started to be launched. The fairlead 44 may have a mobile gate able to close its open section.

[0038] The mechanical connection of the streamer 16 to the arm 30 may be performed by means of a stopper 46 secured to the streamer 16. The stopper 46 is positioned at that end of the streamer 16 that is intended to be articulated to the arm 30. During the launching of the sonar 12, the streamer 16 runs through the fairlead 44. When almost all of the streamer 16 has passed through the fairlead 44, the stopper 46 comes into abutment against the fairlead 44. Dimensions of the cross section of the stopper 46 perpendicular to the axis 36 are greater than dimensions of the internal cross section of the fairlead 44 so as to allow the stopper 46 to come into abutment against the fairlead 44. In figure 3, the streamer 16 is slipping through the fairlead 44. Figure 4 depicts the stopper 46 before it comes up against the fairlead 44, and figure 5 depicts the stopper 46 in abutment against the fairlead 44. Other mutually complementing shapes of the stopper 46 and of the fairlead 44 able to halt the translational movement of the stopper 46 with respect to the fairlead 44 along the axis 36 in the configuration of figure 1 are possible. For example, provision may be made for the stopper 46 to fit conically into the fairlead 44.

[0039] As an alternative to the fairlead 44, the articulation between the arm 30 and the streamer 16 may simply be removable. The articulation formed here by a connection having at least one degree of freedom to rotate, such as, for example, a pivot connection allowing the arm 30 to rotate with respect to the streamer 16 may be disconnectable so as to allow the end of the streamer 16 to be freed from the arm 30 so that the streamer 16 can be wound onto the winch 26. In other words, when the end of the streamer 16 is articulated to the arm 30 at the end 34 thereof, the articulation has one or more degrees of freedom to rotate so as to allow the arm 30 to switch between its two positions: the so-called deployed first position in which the arm 30 is aligned with the streamer 16 and the second position in which the arm 30 is unaligned with respect to the streamer 16, the second position allowing the streamer 16 to be aligned with the second winch 26. In order to allow the streamer 16 to be wound onto the winch 26, this rotational connection is removable. The fairlead 44 makes it possible to maintain guidance of the streamer 16 with respect to the end 34 of the arm 30. It is also possible to completely release the streamer 16 from the end 34 of the arm 30.

[0040] The winch 26 is able to wind in and pay out the streamer 16. An attachment cable 52 is temporarily fixed between the winch 26 and the streamer 16. The attachment cable 52 allows the streamer 16 to be paid out completely in order to bring one of its ends to the arm 30 to which it can be mechanically connected. When the sonar 12 is being brought back up, once the streamer 16 is aligned with the winch 26, the winding onto the winch 26 begins with the winding of the attachment cable 52 and then the winding of the streamer 16 onto the winch 26. The stopper 46 forms an interface between the streamer 16 and the attachment cable 52. The stopper 46 is also wound onto the winch 26.

[0041]As an alternative, it is possible to attach the streamer 16 directly to the winch 26, for example using a shackle secured to the winch 26. In general, any mechanism can be used for attaching the streamer 16 to the winch 26. The attachment mechanism can be maneuvered by the operator who can attach the streamer 16 to the winch 26 when bringing the streamer back onboard the ship and who can detach the streamer 16 from the winch 26 during launch.

[0042] In service, when the sonar 12 is being towed, the streamer 16 is subjected to drag caused by the speed of the ship 10. The drag has a tendency to keep the stopper 46 in abutment against the fairlead 44. Certain maneuvers of the ship 10, notably when it stops moving ahead or starts to move astern, may cancel the drag applied to the streamer 16. The sea state may also at least temporarily cancel out the drag applied to the streamer 16. In order to prevent the stopper 46 from separating from the fairlead 44, it is possible to provide two-way means of immobilizing the streamer 16 with respect to the fairlead 44. These means may be achieved by adherence, for example by means of a tight fit of part of the stopper 46 entering the fairlead 44. Alternatively or to complement this, the two-way immobilization means may be achieved using an obstacle, for example by means of a latch 48 as depicted in figure 6. The latch 48 is articulated with respect to the fairlead 44 and in the locked position catches on a protruding part 50 of the stopper 46. In the unlocked position, the latch 48 releases the protruding part 50 thus allowing the stopper 46 to be removed from the fairlead 44.

[0043] To complement the mechanical connection between the streamer 16 and the arm 30 at the end 34 thereof, the sonar 12 may have an electrical and/or optical connection between the tow fish 14 and the streamer 16. This connection is then disconnectable. More specifically, the streamer 16 may have a fixed connector 54, for example secured to the stopper 46. A cable 56, electrically and/or optically connected to the tow fish 14, may pass inside the arm 30. One end of the cable 56 is equipped with a plug 58 that an operator 60 couples to the fixed connector 54 when the stopper 46 is in abutment against the fairlead 44 or, more generally, when the streamer 16 is mechanically connected to the arm 30. The electrical connection between the streamer 16 and the arm 30 is visible in figures 7 and 8. More generally, any type of connection between the streamer 16 and the tow fish 14 may be employed. The connection may be made without physical contact, for example using a radio frequency connection developed between two terminations situated close to one another, one being positioned in the arm 30 and the other positioned in the fairlead 44 or even in the stopper 46.

[0044] In a variant alternative to connection with physical contact, it is possible to avoid the manual operation of connecting the plug 58 to the fixed connector 54. To do that, the connection points of the plug 58 are incorporated into the fairlead 44. The connection points of the fixed connector 54 remain incorporated into the stopper 46. Connection between the tow fish 14 and the streamer 16 is achieved by inserting the stopper 46 into the fairlead 44.

[0045] Figures 9, 10 and 11 illustrate a first variant of the handling system 20. In this variant, the arm 30 switches from its position unaligned with respect to the streamer 16, allowing the streamer 16 to be aligned with the winch 26, to its position aligned with the streamer 16, by means of the winch 26. During the switch between the unaligned position to the aligned position, the stopper 46 remains in abutment against the fairlead 44. More generally, the streamer 16 is connected to the arm 30. Figures 10 and 11 depict the arm 30 in the position aligned with the streamer 16 and figure 9 depicts an intermediate position of the arm 30 somewhere between its unaligned position and its position aligned with the streamer 16. During the switch between its two positions, the arm 30 pivots about the articulation of its first end 32 with respect to the tow fish 14. The streamer 16 is already in the water and pulls on the end 34 of the arm 30. The attachment cable 52 also applies load to the arm 30 at its end 34. The attachment cable 52 holds the arm 30 in position by balancing the force exerted on the arm 30 by the streamer 16. The switching of the arm 30 between its two positions is accomplished by maneuvering the winch 26: by paying out the attachment cable 52 in order to reach the aligned position and by winding in the attachment cable 52 in order to reach the unaligned position of the arm 30.

[0046] During the launching of the sonar 12, in the first variant of the handling system , it is necessary to release the arm 30 from the attachment cable 52. The operator performs this release as illustrated in figures 10 and 11. The attachment cable 52 may be fixed removably to the stopper 46. The operator 60 then has to intervene on the end 34 of the arm 30, and this may present a danger. Alternatively, the attachment cable 52 may be produced in two parts 52a and 52b, as can be seen in figures 10 and 11. The part 52a is secured to the arm 30 and is fixed to the end 34 thereof. The part 52b is secured to the winch 26. The two parts 52a and 52b are fixed to one another removably, for example by means of a shackle. The attachment cable 52 is released by detaching the parts 52a and 52b. The part 52a can then be stored along the arm 30. Thus, the operator 60 is no longer working at the end of the arm 30 but only at the position of the removable fixing-together of the two parts 52a and 52b. As a further alternative, it is possible to provide an automatic device for connecting and disconnecting the attachment cable 52. Such a device may for example comprise a shackle secured to the stopper 46 and which opens when the tension in the attachment cable 52 drops below a predefined threshold.

[0047] During launching of the sonar 12, after having detached the attachment cable 52 from the arm 30, the winch 24 is maneuvered in order to launch the tow fish and pay out the tow cable 18 to the desired length.

[0048] The sonar 12 is brought back up by reversing the order of the operations described above, namely by: winding in the tow cable 18 by means of the winch 24 to bring the tow fish 14 back up onto the deck 22, attaching the attachment cable 52 to the stopper 46 or attaching the two parts 52a and 52b to one another, operating the winch 26 to bring the arm 30 from its position aligned with the streamer 16 to its unaligned position and to wind in the attachment cable 52 and the streamer 16.

[0049] Figures 12 to 17 illustrate a second variant of the handling system 20. In this variant, the arm 30 switches from its position unaligned with respect to the streamer 16, allowing the streamer 16 to be aligned with the winch 26, to its position aligned with the streamer 16, by means of an actuator distinct from the winch 26. This variant allows the operator 60 to move even further back from the edge of the deck 22 than this operator could in the first variant. In this second variant, there is again the winch 26 and its attachment cable 52 able to restrain the streamer 16 during the launching of the sonar 12 prior to the operation of mechanically connecting the streamer 16 to the arm 30 and more specifically before the stopper 46 comes into abutment against the fairlead 44. During the launching of the streamer 16 and the mechanical connecting to the arm 30, only the gate 38 is open. The electrical connection can also be performed at the time of the mechanical connection. With the connection or connections made, it is then possible to open the gate 40. Figure 12 is a perspective depiction of the sonar 12 of which the streamer 16 has been launched. The tow fish 14 is still on the deck 22. The two gates 38 and 40 are open. The handling device 20 in this second variant comprises an actuator 62, in the inactive position in figure 12. The actuator 62 is for example formed of a cylinder actuator of which the rod 64 is motorized in translational movement and in rotational movement with respect to the deck 22. In figure 13, the rod 64 is depicted in the active position, which is to say applying a force to the arm 30 in order to keep it in the unaligned position, the streamer 16 still being held by the winch 26 by means of the attachment cable 52. With the rod 64 in this position, the winch 26 is maneuvered to release the force applied by the attachment cable 52. Once the attachment cable 52 is no longer applying any force to the streamer 16, all of the force applied to the streamer 16 is taken up by the rod 64 via the arm 30 and the operator 60 can detach the attachment cable 52 from the stopper 46, as depicted in figure 14. In order to continue with the launching of the sonar 12, the rod 64 pivots to bring the arm 30 progressively into its position of alignment with the streamer 16. Figure 15 depicts the arm 30 in an intermediate position, and figure 16 depicts the arm 30 aligned with the streamer 16, the rod 64 having completely released its force on the arm 30 and no longer being in contact therewith. In figure 17, the actuator 62 has regained its inactive position and the winch 24 is ready to pay out the tow cable 18 in order to launch the tow fish 14.

[0050] The sonar 12 is brought back up by reversing the order of the operations described above, namely by: winding in the tow cable 18 by means of the winch 24 to bring the tow fish 14 back up onto the deck 22, operating the actuator 62 to bring the arm 30 from its position aligned with the streamer 16 to its unaligned position, attaching the attachment cable 52 to the stopper 46, unlocking the stopper 46 from the fairlead 44, operating the winch 26 to wind in the attachment cable 52 and the streamer 16. During the winding in of the attachment cable 52, it is possible to stow the actuator 62.

Claims (12)

1. CLAIMS 1. An underwater device (12) intended to be towed by a surface ship (10) and handling system (20) intended to be installed on the surface ship (10) and used for storing and deploying the underwater device (12), the underwater device (12) comprising a tow cable (18), a towed body (14) and a flexible elongate body (16), the towed body (14) being situated between the flexible elongate body (16) and the tow cable (18) during use of the underwater device (12), the handling system (20) comprising two distinct winches (24, 26), the first winch (24) being used for storing and deploying the tow cable (18) and the towed body (14), the second winch (26) being used for storing and deploying the flexible elongate body (16), characterized in that the underwater device (12) comprises an attachment mechanism (52) for attaching the flexible elongate body (16) to the second winch (26) and an arm (30) articulated at a first (32) of its ends to the towed body (14) and at a second (34) of its ends, removably, to the flexible elongate body (16), in a deployed first position, the arm (30) being aligned with the flexible elongate body (16) allowing the first winch (24) to tow the entire underwater device (12), in a second position, the arm (30) being unaligned with respect to the flexible elongate body (16) allowing the flexible elongate body (16) to be aligned with the second winch (26).
2. 2. The underwater device and handling system as claimed in claim 1, characterized in that the articulation of the arm (30) to the flexible elongate body (16) is disconnectable.
3. 3. The underwater device and handling system as claimed in claim 2, characterized in that the underwater device (12) comprises an electrical and/or optical connection between the towed body (14) and the flexible elongate body (16) and in that the electrical and/or optical connection is disconnectable.
4. 4. The underwater device and handling system as claimed in one of the preceding claims, characterized in that the arm (30) comprises, at its second end (34), a fairlead (44) for guiding the flexible elongate body (16) and in that the flexible elongate body (16) comprises a stopper (46) configured to come into abutment against the fairlead (44), the stopper (46) being positioned at one end of the flexible elongate body (16), the end articulated to the arm (30).
5. 5. The underwater device and handling system as claimed in one of the preceding claims, characterized in that the handling system (20) comprises an actuator (26; 62) configured to cause the arm (30) to switch between its two positions: the position aligned with the flexible elongate body (16) and the position unaligned with respect to the flexible elongate body (16).
6. 6. The underwater device and handling system as claimed in claim 5, characterized in that the actuator is the second winch (26).
7. 7. The underwater device and handling system as claimed in claim 5, characterized in that the actuator (62) is distinct from the second winch (26).
8. 8. The underwater device and handling system as claimed in one of the preceding claims, characterized in that the handling system comprises two gates (38, ) that can be maneuvered separately from one another, a first of the two gates (40) being positioned between the first winch (24) and the sea, a second of the two gates (38) being positioned between the second winch (26) and the sea, and in that when the arm (30) is in the second position, the first of the two gates (40) can remain closed.
9. 9. The underwater device and handling system as claimed in one of the preceding claims, characterized in that the attachment mechanism comprises an attachment cable (52) that can be fixed between the second winch (26) and the flexible elongate body (16).
10. 10. A method for implementing the underwater device and handling system as claimed in one of the preceding claims in order to launch the device, characterized in that in order to launch the underwater device (12) the method consists in performing the following sequence of operations: a. paying out from the second winch (26) in order to launch the flexible elongate body (16), b. connecting the flexible elongate body (16) to the second end (34) of the arm (30) in the unaligned position, c. bringing the arm (30) into the aligned position, d. paying out from the first winch (24).
11. 11. The method as claimed in claim 10 for implementing the underwater device and handling system as claimed in claim 6, characterized in that it consists, between operations c and d, in: e. detaching the flexible elongate body (16) from the second winch (26) by maneuvering the attachment mechanism (52).
12. 12. The method as claimed in claim 10 for implementing the underwater device and handling system as claimed in claim 7, characterized in that it consists, between operations b and c, in: f. operating the actuator (62) to take up the load of the flexible elongate body (16) on the arm (30), g. detaching the flexible elongate body (16) from the second winch (26) by maneuvering the attachment mechanism (52), operation c being performed by maneuvering the actuator (62).