FR2567479A1 - Methods and devices for moving a floating load on the water - Google Patents

Abstract

The present invention relates to methods and devices for moving a floating load on the water. A device according to the invention for moving, on the water, a floating load 2, for example a target 5 mounted on two floats 4, by means of a tug-boat 1, comprises a rigid link, for example a trellis structure 3, 6 which is fixed to the load and which carries a spherical ball joint 7 which presses into a spherical socket (seat) 8 fixed to the tug-boat. A device for limiting the relative angular travel comprises a cable 23 the front end of which is hooked to a hooking means 22 fixed to the stern of the tug 1, which cable passes into a fairlead 24 carried by the structure 3, then over return pulleys 25, 27 and is fixed to the stern end of the structure 3. One application is the movement on the water of cumbersome floating loads.

Description

Methods and devices for moving on water utie floating charge ,.

 The present invention relates to methods and devices for moving floating loads by means of a towing vessel.

 The technical sector of the invention is that of shipbuilding.

 The displacement on the water of non-self-propelled floating loads, for example barges or barges or craft damaged by propellers or particular loads such as floating dams or large prefabricated floating elements intended for example for constructions at sea (platforms, reefs or artificial islands etc ...), is carried out to date according to three processes.

 In a first process called towing, a towing vessel tows the towed load using a rope (rope, steel cable, chain), called a trailer. "This trailer obviously has mechanical strength and Geometric configuration adapted to the current operation.

 Towing only allows for forward or large diameter rotations, so slow changes and one or more auxiliary buildings are required for maneuvering at the port. Towing requires a large area of water for safe maneuvers, but it allows a great freedom of relative evolution between the tug and the towed load. However, it presents risks: the risk that the trailer engages in the propellers of the tug if it comes to take slack, the risk that the trailer breaks if it comes to tighten suddenly and, in the case of a trailer steel, the risk that it clings to the bottom if it takes too much slack.

 Following a second process called towing "torque", the tug is placed parallel to the load to move, which he moored with his front and rear.

 This system allows relatively easy evolutions even in a restricted body of water, for example on a watercourse.

 On the other hand, it removes in a very large proportion the possibilities of relative movement between the tug and the towed load and, consequently, it can only be used on a fairly calm sea.

 The third known method for moving a floating load is the stuffing process. The propelling boat sits at the back of the load and pushes it in front of him.

 Being tied to the load, the propeller can direct it at will to the right or to the left or stop.

 The maneuverability of the coupling is very good even on restricted water bodies. But this process is reserved for calm streams. It can not be used at sea because of relative movements that involve considerable forces as soon as the tonnages are large.

 The object of the present invention is to provide new means for moving a towed floating load by a tug or propeller vessel, means which combine the advantages of the three currently known methods, while overcoming most of the disadvantages of each of these methods. this.

 These objectives are achieved by a method that includes the following operations. The floating load is connected to said tug by a rigid connection, a point of which rests on said tugboat and is connected thereto by an articulation having several degrees of freedom of rotation. Advantageously, it connects, on the other hand, said rigid connection to said towing vessel by a damping device and limiting the angular movement between the link and the towing vessel.

 A device according to the invention for moving a floating load on the water by means of a tugboat comprises a rigid connection which connects a point of said towing vessel to said floating load which is hitched behind said tugboat, which rigid link comprises a one of its ends an articulation has several degrees of freedom in rotation which connects said structure to said tugboat or said floating load.

 The device further comprises an angular displacement limiter comprising a cable whose end is fixed to the rear of said tugboat and the other end of which is fixed to said rigid connection.

 The invention results in new means for moving a floating load on a body of water by means of a tugboat.

 The means according to the invention have the following cumulative advantages.

 - They allow towing at sea or on waterways with remarkable maneuverability, eliminating all the dangers inherent in a flexible trailer.

 - They allow the convoy to stop while keeping the towed load on the spot.

 - They allow movement in reverse.

 - They allow to absorb, without giving rise to exaggerated constraints, all relative movements between the towing vessel and the towed load due to rolling, pitching or laces.

 - They allow evolutions on the spot of the coupled assembly.

- They allow the passage of pipes or cables of transport of energy, fluids or information between the towing vessel and the towed load without risk of breakage of the cables or the pipes
The following description refers to the accompanying drawings which show, without limitation, examples of embodiments of devices according to the invention.

 Figure 1 is a longitudinal section of a tugboat pulling a floating target hitched to the stern of the boat.

 FIG. 2 is a view from above of FIG. 1.

 Figure 3 is a rear view along II-II of Figure 1.

FIG. 4 is a partial cross-section according to
IV-IV of Figure 1.

 Figures 5 and 6 are a plan view and an elevational view of a device for limiting relative angular movement between the towing vessel and the towed floating load.

 Figures 7 and 8 are schematic views in elevation and top view of an alternative embodiment of an angular deflection device.

 Figures 9 and 10 are views in elevation and from above of an alternative use of a coupling device according to the invention.

 Figures 11 and 12 are elevational views and a plan view of a second application of a device according to the invention.

 Figures 1 and 2 show a tugboat 1, of any known type, which tows a floating load 2, which is coupled to the rear of the tractor by a rigid connecting member 3.

 In the example shown, the floating load is constituted by a target 5 which is carried by two floats 4d, 4g. This floating target is used for sea trials of shots of various remote-controlled or non-controlled machines, as well as for tests of active or passive jamming devices in the case of remote-controlled machine tests.

 In this application, the target must be placed far enough from the towing vessel and it is coupled thereto by a coupling member 3 constituted by a lattice structure of great length, for example an overall length of the order of 40 m. This length is necessary to place the target away from the towing vessel in the event that the tests are real shots.

 The towing of such a floating load, of great length, poses problems.

 If splinted behind the tug with a towline, the target can be easily moved away from the tug but cable towing of a heavy load poses difficult problems. The towing cable is subjected to very violent forces during a sudden tension of the cable following a softening and this tension leads to frequent breakage of the cable. In addition the cable may be caught in the propellers of the tug. Finally, a floating load towed by a cable of great length is difficult to maneuver and it requires for evolutions of large water bodies.

 Figures I to 4 represent a coupling device which makes it possible to tow a large target on the water, avoiding the disadvantages of cable towing while moving the target away from the towing vessel.

 The front end of the trellis structure 3 has the shape of a gooseneck which is equipped at its front end with a spherical ball 7 which bears on a spherical seat 8 carried by the towing vessel 1.

 FIG. 4 is a partial cross-section, on a larger scale, on which the front ends of two tubes 9 and 10 forming part of the structure 3 are seen. These tubes are welded on a plate 11 on which the seat 12 is fixed. a pivot 13 of biconical shape, of z axis z1. The pivot 13 has two threaded ends. The upper end is fixed to the seat 12 by a nut 14. The lower end of the pivot 13 is engaged in a conical bore of a spherical ball 7 and the ball is fixed on the lower end of the pivot by a nut 15 which is placed in a hollow recess of the patella 7.

 The ball 7 is supported on the ball seat 8 which is fixed at any point of the longitudinal axis of the towing vessel, preferably in the central region thereof to minimize the influence of the pitch of the tug on the front of the load.

 The seat 8 is placed on a damping disc 16 made of elastomer. The seat 8 and the disc 16 are placed inside a cylindrical bowl 17 which is fixed on a base plate 18 which is itself mounted in two transverse slides 19d, 19g, fixed to the deck of the tug 12 so that the bowl 17 and the base plate 18 form a carriage which can slide laterally and which allows to center the load with respect to the longitudinal axis of the tug.

 The bowl 17 comprises, at its upper end, a male thread on which is screwed a nut 20 which holds the seat 8 of the bowl 17 and the ball 7 on the seat.

 The nut 8 has a spherical bore, so that the ball 7 can rotate freely in all directions, the angular displacement around the horizontal axes being however limited to about +300 on either side of the equilibrium position. . A bellows 21 envelops the ball joint.

 The coupling device consisting of a rigid connection 3 and a ball joint 7 makes it possible to absorb all the relative movements between the towing vessel and the towed load due to rolling, pitching and laces, without giving rise to no constraint in rotation in the drawbar, in the towing vessel or in the coupled load.

 This spherical ball joint device can be replaced by a cardan system with three axes of rotation orthogonal or not.

 On the other hand, in applications where there are no yaw movements, it suffices to use a hinge having two degrees of freedom in rotation about two rectangular horizontal axes.

 In this case, a universal joint, whose spider pivots about two horizontal axes, can replace the ball joint 7, 8.

 The coupling device described above makes it possible to stop and immobilize the towed load by immobilizing the towing vessel without the risk of there being between them a drift other than a rotation of vertical axis.

 It also makes it possible to maneuver the towed load in reverse as well as in front of where it is easy to evolve in ports or on relatively small planes.

 The system described allows towing at sea, even by strong swell, and it removes all the risks and drawbacks inherent in towing cables.

 The device described above is supplemented by a so-called angular movement limitation device, in order to allow the on-site development of the tug and hitch assembly without risk of damaging the superstructures of the tug when the tug is pivoted around. the vertical axis z z1 of the pivot bearing the ball 7.

 The system introduced during a relative displacement of the tug relative to the load in rotation about the vertical axis an antagonistic torque tending to thwart said relative displacement.

 In fact, if the device described above was used without completing it, the tug could pivot freely about the z axis z1 without causing the towed load and when it had pivoted by a certain angle, the superstructures located at 'before the tug would hit the gooseneck 6.

 To limit the relative angular displacement of the tug relative to the towed load to about 900, a ring 22 located at the center of the rear end of the tug is connected to the rigid structure 3 by a cable 23.

 Figures 5 and 6 are partial views in plan and elevation showing an angular deflection device.

On these views we find the cable 23 which is hooked on a ring 22, or any other equivalent attachment device, fixed in the center of the rear end of the towing vessel 1.

 The cable 23 passes through a fairlead 24 which is fixed for example at the junction between the rectilinear structure 3 and the gooseneck 6 and which comprises guide pulleys of the cable.

 The cable 23 then passes over a deflection pulley 25 which is suspended from an extensible cable 26, for example a "bungee cord", the ends of which are fixed to the structure 3. The extensible cable 26 has the function of preventing the cable 23 can not take slack. The cable 23 passes over another deflection pulley 27 and then into guide rings 28 and the end of the cable is fixed behind the rigid structure 3, so that the cable 23 has a length of the order from 15 to 20 m.

 The position taken by the tugboat when the tugboat has pivoted 900 around the ball 7 is represented by dotted lines on the fillet 5 and the position of the cable located between the fairlead 24 and the new position is shown in broken lines. 22 'of the hook 22.

 The distance separating the position 22 from the fairlead entrance increases as the tugboat pivots and the increase in cable length is provided by the extension of the cable 26 and then by the clean extension of the cable 23.

 As the angular displacement in the horizontal plane between the towing vessel and the towed load increases, the tension of the rope increases and the resultant of the tensions of the two sections of cable located on either side of the fairlead pushes on it and exerts a torque on the rigid structure 3 which tends to rotate it in the direction that reduces the angular movement.

 Thanks to this angular displacement limiter device, it is possible to maneuver the towed load by rotating on site the assembly formed by the towing vessel and by the load reached behind it and this without risk of damaging the superstructures of the tugboat.

 The example shown has a rigid coupling member of great length and it is therefore possible to use a cable 23 of great length, so that the elongation of the cable compensates for variations in distance between the fairlead 24 and the 22. In the case of a shorter coupling member, the cable can be passed over pulleys carried by elastic devices, for example on a pulley 29 carried by a longitudinal jack 30 and on pulleys 31, 32 carried by transverse cylinders 33, 34 as shown schematically in Figures 7 and 8.

Figures 1 to 8 illustrate, by way of illustration, a particular application relating to the coupling of a target behind a towing vehicle. A box can
be placed under the front end of the trellis structure 3 to support it when the structure is uncoupled from the towing vessel.

 It is specified that the described use example is not limiting.

 A device according to the invention can be used to harness behind a tugboat all sorts of floating loads, for example barges or unmotivated barges, prefabricated floating boxes intended to build platforms or artificial reefs of tanks, floating dams for stop pollution, gear to skim pollution on the surface of the water etc.

 The devices according to the invention can be used to tow floating charges on the sea, on lakes, bats and, in general, on any body of water.

 FIGS. 9 and 10 show schematically another example of application in which a floating boom consisting of a net 36 and inflatable tubes 37 is suspended from a transverse truss beam 38 which is hitched behind a towing vessel 39 by a bar hitch 40 which comprises, at its front end, a ball joint or a universal joint 41.

 A travel limiter system 42 is installed between the stop bar at point 43 and the towing boat at point 44.

 FIGS. 11 and 12 diagrammatically show a third example of application in which the floating load to be maneuvered consists of a floating gantry 45 supporting a submersible 46 operated by a handling system 47 (winch or the like), integrated with the gantry. A drawbar 48 coupled on the one hand by its rear end to the frame 45 by a horizontal-transverse axis joint 49 is connected at its front end to the tug 50 by a ball joint or cardan joint 51.

 A travel limiter system 52 is disposed between the drawbar at point 53 and the towing vessel at point 54.

 The coupling devices according to the invention can be used in particular in the case where the extent of the body of water is small or has a complex shape, for example in port basins or on watercourses, in the case where the radii of gyration are weak, in the case where there are bad conditions of wind, of swell and in the case where the height of dunnage is important compared to the draft of the load as well as in the case where the coupling is subject to significant speed variations and the need for maneuvering in reverse.

 The drawings show exemplary embodiments in which the rigid coupling bar is secured to the towed load and the ball joint is placed on the tug. it is specified that the rigid drawbar can be secured to the tug and the joint can be at the rear end on the towed load.

 The term "tugboat" has been retained to designate the towing vessel, although it is not a towage in the strict sense, ie by means of a towline.

 The shape of the tug and the towed load is indifferently a monohull, a catamaran or any other form.

 The tow bar and the link connecting it to the towing vessel do not need to be dimensioned to withstand strong shocks as the towed load is rigidly coupled to the towing vessel and never reverses the direction of speed. brutal towed load resulting in very strong accelerations.

 Finally, the rigid connection allows the easy passage of any form of pipe or cable without it causes a significant maneuvering complexity.

 Moreover, due to the rigidity of the connection, there is no accumulation of energy that can cause a serious accident in the event of a break, such as with a towing cable.

Claims (14)

 Method for moving a floating load (2) on the water by means of a tugboat (1), characterized in that said floating load (2) is connected to said tug (1) by a rigid connection ( 3), a point of which rests on said towing boat and is connected thereto by a hinge (7, 8) having several degrees of freedom in rotation.  2. Method according to claim 1, characterized in that the front end of said rigid connection carries a spherical ball (7) which is maintained supported in a spherical seat (8) attached to a point of said towing vessel (1).  3. Method according to claim 1, characterized in that the front end of said rigid connection is connected to said towing vessel by a universal joint.  4. Method according to claim 1, characterized in that one connects the rigid connection (3) to the towing vessel (1) by a damping device and limiting the angular movement between the connection and the boat.  5. Device for moving a floating load (2) on the water by means of a tugboat (1), characterized in that it comprises a rigid connection (3) which connects a point of said tugboat (1) to said floating load (3) which is hitched behind said tugboat (1), which rigid link has at one of its ends a hinge (7, 8) with several degrees of freedom in rotation and in translation which connects said connection to said tugboat and said floating load.  6. Device according to claim 5, characterized in that it further comprises an angular displacement limiter comprising a cable (23), one end of which is fixed to the rear of said towing vessel (1) and whose other end is attached to said rigid.  7. Device according to claim 5, characterized in that said hinge is constituted, on the one hand, by a spherical ball (7) which is supported byunpivot vertical (13) which is fixed to said rigid connection and secondly by a spherical seat (8) which is attached to said tugboat (1) or said floating load (2).  8. Device according to claim 7, characterized in that said spherical seat (8) is supported by a carriage (17, 18) which slides in two transverse rails (19g, 19d).  9. Device according to claim 5, characterized in that said hinge is constituted by a cardan with two or three degrees of freedom in rotation.  10. Device according to claim 6, characterized in that said cable (23) passes over one or more return pulleys (25, 29, 31), which are connected to said rigid connection by elastic supports such as an extensible cable ( 26) or jacks (30, 32).  11. Device according to claim 6, characterized in that said cable 23 acts as an energy accumulator and creates the appearance of the opposing torque.  12. Device according to claim 6, characterized in that the cable (23) is associated with a cylinder (30) energy accumulator.  13. Device according to claim 5, wherein the rigid connection is an integral part of the floating load integral with the latter.  14. Device according to claim 5, characterized in that the rigid connection may be at one or more degrees of freedom to the point where it is related to the load towed by its rear end.