DEPLOYMENT AND RETRIEVAL OF FLOATABLE OBJECTS

This invention concerns the automated deployment and retrieval of floatable objects such as one or more fenders to be placed against the hull of a large vessel when moored against another vessel or other structure. Other floatable objects to be deployed and retrieved may include, for example, a lifeboat or working platform, or a submersible vehicle.

In the case of fenders, typically, four or more large air-filled fenders need to be lowered onto the surface of the water and then retrieved when required to be stowed on deck or on the quayside. Fenders are usually suspended from davits on hauling lines connected to winches for lowering and raising the fenders when required. Such fenders typically are some two metres long, weighing in the order of five tonnes and deployed as floatation devices.

The fenders are deployed usually linked together by a flexible chain or cable and at least one of a series of such fenders will be tethered to the vessel or to the quayside to prevent them from drifting away from the side of the vessel.

The deployment and retrieval operation is traditionally carried out by a crew in a small boat manually connecting and disconnecting the hauling lines with respect to the fenders. This is a hazardous operation, particularly in adverse sea conditions and can easily cause injury or even loss of life.

It is an object of the present invention to provide a system of deployment and retrieval of such objects which can be operated remotely and automatically thus avoiding the need for personnel to be present on the water.

The invention involves the use of so-called ball and taper devices forming a two-part male/female connector, the male part of which forms a tool including a mandrel having a tapered wall part surrounded by a cage with balls or rollers cooperating with the tapered wall part thus to move outwardly upon relative movement of the body and the cage such that the balls or rollers extend through apertures in the cage to grip a surrounding wall of a female part into which the tool is placed. Such devices are known,

for example, for the retrieval of pipes by locating the tool inside an end region of a pipe so that the balls or rollers engage the internal surface of the pipe to grip it.

According to a first aspect of the present invention there is provided a system for deployment and retrieval of a floatable object, the system including retrieval means for hauling the object into an elevated stowed position, the retrieval means comprising at least one hauling line, a winch for reeling in and letting out the hauling line, and a connector for attaching and releasing the hauling line with respect to the object; characterised in that the connector comprises a two-part device, one part of which is provided on the hauling line, the other part being provided on the object; and in that the two parts are adapted automatically to become locked together when inter-engaged and when tension is applied to the hauling line.

The object may be a fender for a water-borne vessel.

The hauling line and two-part connector may be provided at two opposed ends of the object.

The or each two-part connector may comprise a ball and taper device with remotely operable releasing means to enable disengagement and separation of the two parts of the connector.

One part of the or each two-part connector may include a fairing to facilitate automatic docking and inter-engagement of the parts.

The system may include a plurality of objects connected together by flexible lines.

At least one of the objects may be tethered to prevent it from drifting away from the vessel when released from its associated hauling line.

The connector part associated with the object may be formed as a receptacle rotatably mounted on the object and counterbalanced to remain upright in a position to receive and engage the connector part on the hauling line.

According to a further aspect of the present invention there is provided a method of deployment and retrieval of one or more floatable objects, comprising the steps of

suspending the or each object on at least one hauling line attached to a winch, with a two-part connector between the object and the hauling line, the two parts of the connector being automatically locked together releasably when inter-engaged and with the line in tension, operating the winch to pay out the hauling line and to lower the object until it becomes water-borne, remotely releasing the two-part connector to detach the hauling line from the object, and subsequently retrieving the object by remotely reengaging the two parts of the connector and operating the winch to draw up the hauling line thus applying tension thereto so that the two parts of the connector become locked together to enable the object to be lifted and retrieved.

The or each hauling line may be retracted by the winch after release of the associated object.

A plurality of objects linked together by flexible lines may be simultaneously deployed and simultaneously retrieved, at least one of said objects being tethered to prevent it from drifting away.

The or each connector may be a ball and taper device including a tool which is lowered into a receptacle to engage the connector and automatically to lock it when tension is subsequently imposed upon the hauling line, inter-engagement being assisted by a fairing at the mouth of the receptacle and by means to maintain the receptacle in an upright position.

An embodiment of the invention, as applied to the deployment and retrieval of fenders alongside a vessel or quayside, will now be described, by way of example only, with reference to the accompanying drawings in which:

Figs. 1 a to 1 c schematically illustrate a known ball and taper device in three operational positions;

Fig. 2 illustrates a vessel having a fender system and method of deployment according to the present invention;

Fig. 3 is a perspective view of a two-part connector to enable a fender to be deployed and retrieved automatically, and shown in the position just prior to the two parts becoming engaged and locked together;

Fig. 4 is a similar view showing the connector locked; and

Fig. 5 shows the connector disengaged for retrieval of the hauling line.

Referring initially to Figs. 1 a to 1c, a known ball and taper device comprises a tool 24 having a mandrel 25 surrounded by a cage 26 with balls or rollers 27 partly exposed through apertures in the wall of the cage 26 and residing in tapered ramps 25a formed on the outer surface of the mandrel 25 at spaced positions circumferentially and longitudinally thereof.

A ball and taper device of this kind operates such that relative movement of the mandrel 25 and the cage 26 causes the balls 27 to ride up or down the ramps 25a so that the balls either extend outwardly through their associated apertures or are retracted within them.

In Fig. 1 a the tool 24 is shown at the commencement of its introduction into a receptacle 19.

In Fig. 1 b the tool 24 is fully inserted into the receptacle 19 and the balls 27 are at the innermost positions of their associated ramps 25a.

Referring now to Fig. 1c, upon subsequent upwards movement of the mandrel 25 relative to the cage 26 the balls 27 are caused to ride outwardly on their ramp surfaces 25a and to extend through their associated apertures in the cage 26 thus to grip the inner wall surface of the receptacle 19 so that the two parts of the device, namely the tool 24 and the receptacle 19, become firmly locked together enabling the receptacle 19 to be lifted.

In ball and taper devices of this kind the two parts can be released by clamping together the mandrel 25 and the cage 26 such that the balls 27 reside at the innermost end of the ramp surfaces as can be seen in Fig. 1 b. In this condition therefore the tool 24 can e withdrawn from the receptacle 19.

Referring now to Fig. 2, large vessels such as that illustrated at 10 are often required to be moored for an extended period either against another vessel or other structure while

cargo is loaded or unloaded. During this time it is essential to protect the ship's hull 1 1 with a series of fenders 12, usually large air-filled buoys weighing in the region of five tonnes each to be water-borne against the side of the vessel and inter-connected end- to-end by chains or cables 13.

The fenders 12 are adapted to be lowered and retrieved on hauling lines 14 mounted on davits 15 and connected to associated winches on board the vessel and each of the hauling lines 14 is releasably attached to a connector 17 at one end of an associated fender. Preferably, at each end of a series of objects a tethering line 16 is provided to prevent the group of tenders from drifting away from the vessel.

Conventionally, it is necessary for a crew in a small boat to connect and disconnect the hauling lines 14 with respect to the connectors 17, and this can be a hazardous procedure, particularly in adverse sea conditions.

Referring now to Figs. 3 to 5 and in accordance with the present invention, each connector 17 is formed as a two-part ball and taper device of the kind shown in Figs. 1 a to 1 c and comprising a plate 18 to be permanently attached to an end of a fender and having a horizontally extending shaft on which is rotatably mounted the receptacle 19 being one part of the two-part connector. A collar 20 ensures that the receptacle 19 is correctly located and freely rotatable on the shaft of the plate 18, and a counterweight 21 ensures that the receptacle 19 always remains in an upright position as illustrated in Fig. 3.

The receptacle 19 includes an open tubular part 22 which at its upper open end extends out into a fairing 23.

The other part of the two-part connector comprises the tool 24 of the ball and taper device having the mandrel 25 and the cage 26 with balls or rollers 27 partly exposed through apertures in the cage 26.

In this example, when the tool 24 is lowered into the tubular part 22 of the receptacle 19 the balls 27 are loosely engaged within the apertures, but when a hauling line 14 is connected by a shackle 28 to the mandrel 25 and tension is applied to the hauling line then the relative movement of the body within the cage causes the balls to ride up their respective ramps to grip the inner wall surface of the tubular receptacle so that the two

parts of the connector are then firmly locked together. The greater the load on the hauling line 14 the greater is the locking inter-engagement of the two parts of the connector and so the fenders 12 can be hauled upwardly by their respective winches onto the deck of the vessel or onto an adjacent quayside. The locked and hauling condition is illustrated in Fig. 4.

As can be seen in Figs. 3 to 5, the mandrel 25 of each tool 24 has a pair of release catches 29 both connected to a release line 30.

When the fenders are deployed on the surface and it is required to release the hauling lines 14, the release line 30 is pulled thus rotating the catches 29 which causes the ball cage 26 to be retracted as illustrated in Fig. 1 b, whereupon the balls 27 release their grip upon the internal wall surface of the receptacle and so the tool 24 can be withdrawn therefrom and the hauling lines 14 can be retracted from the fenders.

When it is required once again to retrieve the fenders then the hauling lines 14 are again lowered so that the connectors 17 become re-engaged, as illustrated in Figs 1 a to 1 c, to allow the fenders to be winched up onto the deck.

By providing a hauling line 14 and connector 17 at each end of each fender and by simultaneously operating all of the associated winches, the series or group of fenders may be deployed and retrieved simultaneously and remotely without the need for manual intervention at sea level and so the whole operation can be carried out automatically and considerably more safely than the conventional method involving crews attaching and releasing the hauling lines manually.

In the example shown, the fender system is provided on board the vessel, but equally it could be provided as a fixture on a quayside and deployed to protect the hull of a moored vessel.

Also, the floatable object or objects to be deployed and retrieved may be, for example, one or more lifeboats or working platforms, a floating hose used in oil or gas transfer, or a submersible vehicle such as a small submarine. Even when the object or objects are occupied by personnel, it is of considerable advantage to be able to connect and release the hauling line or lines automatically, thus avoiding the need for manual intervention in what can be hazardous conditions.