GB2351482A

GB2351482A - A mechanised fender for marina-based craft

Info

Publication number: GB2351482A
Application number: GB9915446A
Authority: GB
Inventors: Richard Garfield Meredith
Original assignee: Individual
Current assignee: Individual
Priority date: 1999-07-01
Filing date: 1999-07-01
Publication date: 2001-01-03
Anticipated expiration: 2019-07-01
Also published as: GB2351482B; GB9915446D0; WO2001002241A1

Abstract

A mechanised fender pushes a craft away from the pontoon against her mooring lines, and normally maintains a gap between the pontoon and the craft's conventional fenders, thereby minimising hull / gel-coat damage. A spring-actuated torque-arm 3, secured to a spring-housing 1, directs its force to the craft via a removable variable length connecting-arm 5, and permanently secured boat attachment 7. Universal-joints at either end of the connecting-arm 5, together with its screwed-rod section, and the high rangeability travel of the torque-arm 3, cater for all movement of the craft relative to the pontoon. A removable foot-lever (9, Fig 10), enables torque-arm 3 to be accurately positioned, whilst engaging a sliding-plug 4, with the guide on the connecting-arm 5. The spring-housing 1, may be releasably connected to the surface of the pontoon, by clamp 2, or mounted below the surface of the pontoon, and permanently bolted to the pontoon structure.

Description

2351482 A MECIED FENDER FOR MA - BASED CRAFT This invention, relates to a

mechanised fender for marina-based craft, which in normal weather conditions, will maintain a gap between the pontoon and the craft's conventional fenders, by pushing the craft away from the pontoon, against her mooring lines.

Conventional fenders normally take the form of variously shaped plastic objects filled with air, and are hung over the side of a craft to protect her hull from contact with the pontoon to which she is moored. Continual squeezing of conventional fenders between the craft's hull and the pontoon, causes wear and unsightly damage to the gel-coat of the craft's hull (topsides), and reduces the craft's value. New boats can look unduly marked in only two seasons of use, and the damage is generally more noticeable on coloured hulls. To reduce this damage, some owners cover their fenders with protective "socks", but these are only partly effective, and only if regularly washed in clean non-salty water. Other owners employ extra lines in order to hold their craft away from the mooring pontoon, but these lines generally require the adjacent pontoon to be free of other craft. Since most marina-based pleasure craft are moored to their pontoons for a very high percentage of their life, hull damage caused by conventional fenders is a major cause of depreciation- The invention maintains a suitable gap, during normal weather conditions, between the pontoon and the craft's conventional fenders, thereby virtually eliminating hull damage from this source. Only during gale/stonn conditions, when transient surges in the inarina can cause a large relative movement between craft and pontoon, will the invention allow itself to be overpowered by surge forces, and the craft's conventional fenders to temporarily take over. By limiting the strength of its "protective pusW', the invention eliminates any possibility of excessively high point contact forces on the craft's hull during transient surges caused by gale/storm conditions. The invention is specifically designed to enable easy attachment and detachment, to and from the craft, during gale/storm conditions, when the relative movement between craft and pontoon can be considerable. Since the glass-fibre hulls of most pleasure craft are not designed to withstand high tension forces, the invention automatically detaches itself should the craft break loose from her mooring lines for any reason, or should the owner accidentally make way before detaching the invention- Accordingly, this invention for a mechanised fender, comprises a double torsion spring, contained within a spring housing, acting on a removable torque-arm connected to a sliding-plug, all of which must be attached to the pontoon, approximately amidships of the moored craft. Under spring action, the torque-arm pushes the craft away from the pontoon, against her mooring lines, via a variable length connecting-arm. The torque-arm connects to the connecting-arm via the sliding-plug, which incorporates a universal joint. The connecting-arm in turn, connects via a second universal joint, to the craft at a small permanent attachment which is secured on or near the gunwhale, approximately amidships.

The spring-housing must be designed and mounted such as to resist the torque-reaction caused by movement of the torque-arm, and may be attached to the pontoon in various ways, depending on the particular design of pontoon. Two main configurations for attachment to the pontoon are envisaged as follows: - (i) Surface --- the spring-housing is releasably clamped to the top of the pontoon planking. Advantages of this method include independence of the exact moored position of the craft, and that no modifications to the pontoon are required.

(ii) Sub-surface --- the spring-housing is permanently bolted to the pontoon structure, immediately below the pontoon planking, with a slot in the latter, to cater for the removable torque-arm. Advantages of this method include reduced blockage of the walkway, secure attachment, and resistance to theft.

Since the ' Sub-surface' method of attachment may require agreement with the marina authorities, and liaison with the particular pontoon manufacturer to determine the appropriate bolting requirements, a detailed design for a suitable spring-housing and bolting arrangement is not included in this description, but in every other respect, the 'Surface' and 'Sub-surface' designs will be the same. It is envisaged that the particular advantages and disadvantages of both ' Surface' and 'Sub-surface' methods of attachment, will be taken into account by potential owners of the invention, and that each method will have appeal for different reasons.

Additional important features of both the 'Surface' and 'Sub-surface' methods of attachment, include the following:- (i) A removable foot lever attaches to the torque-arm, and allows the spring force to be overcome and easily controlled, whilst simultaneously engaging the sliding-plug into the connecting-arm. This lever also incorporates a spanner fitting, which is used to attach and detach the torque-arm from the spring- housing. When not in use, the foot lever is removed from the torque-arm.

(ii) The connecting-arin incorporates a screwed rod section, which in addition to providing variable length, allows for the necessary twisting movement, in order to cater for the pitching motion of the craft.

(iii) The narrow end of the torque-ann is provided with a sufficiently long travel, such that adequate spare movement is available beyond the point where surges, caused by storm conditions, may have overcome the spring actuated torque-arm, and momentarily pressed the craft to the pontoon, hard against her conventional fenders.

(iv) The sliding-plug automatically detaches itself from the connectingarm, in order to prevent tension forces from being exerted on the hull.

(v) A conical shaped guide is provided at the end of the connecting-arm, in order to facilitate entry of the sliding-plug during galelstorm conditions, when the relative movement between pontoon and craft can be considerable. This guide also forms a guard, to prevent entrapment of fingers during engagement of the sliding-plug with the connecting-arm.

(vi) The small permanently secured boat attachment, incorporates a conical entry, in order to facilitate single-handed connection of the connecting-arin from the pontoon, and a key, which "captures" the removable connectingarm once it has been lowered to its operating position.

(vii) All materials, including the spring, shall be fully corrosion resistant, and suitable for extended use in a marine environment. The most suitable material in general use is probably 316 stainless steel, but consideration could also be given to marine grade aluminium, plastic, and carbon-fibre, for certain parts. All bearings shall incorporate selflubricating corrosion resistant bushes.

A specific embodiment of the invention will now be described by way of an example, with reference to the accompanying drawings in which:- Figure 1 shows in perspective, the mechanised fender in use. Figure 2 illustrates a design for the spring-housing and clamp. Figure 3 illustrates two designs for the torque-arm 1 sliding-plug. Figure 4 illustrates two designs for the connecting-arm. Figure 5 illustrates a design for the spring-unit. Figure 6 illustrates a preferred design for the boat attachment Figure 7 illustrates a design for the spigot connector. Figure 8 illustrates a design for an alternative boat attachment. Figure 9 illustrates a design for the removable foot lever. Figure 10 illustrates the connecting of the mechanised fender to the pontoon and craft.

The mechanised fender is shown in FIG. 1, pushing a craft away from the pontoon, against the restraining forces of her mooring lines ( not shown). These mooring lines would be adjusted to set the normal gap between pontoon and conventional fenders, at about 150 m.m., thereby allowing for a considerable amount of surging/relative movement, before contact is made between pontoon and conventional fenders. It is envisaged that the normal protective push force exerted by the mechanised fender, (of the order of 20 kg. for a 12 metre craft) will only exceptionally be fully overcome by transient surges caused by gale/storm force conditions in the marina. The "throV' of the narrow end of the torque-arm 3, is such that even if storm conditions force the craft's conventional fenders hard against the pontoon during surges, there is still adequate further travel possible. In this way, the mechanised fender can never exert an excessively high point loading force on the craft's hull, and yet maintains a satisfactory distance between pontoon and conventional fenders at all normal times, except possibly, during the transient surges caused by storm conditions.

The spring-housing 1, shown in FIG. 1, is quickly and easily clamped to the owners side of his/her pontoon, and would normally be removed completely, before the craft leaves her pontoon berth. The particular designs of the spring-housing 1, and associated clamp 2, shown in FIG. 1, and FIG. 2, are suitable for use with pontoons currently being produced by a leading U.K. manufacturer, whose products feature widely in the U.K. and abroad. Different designs of pontoons may require different designs for the clamping system. The spring-housing 1, is releasably clamped to the pontoon by an adjustable clamp 2, which engages with a wooden member that makes up the side of the pontoon as shown in FIG.2. Slots in the ends of the clamp 2, mating with the spring-housing 1, enable the latter to be clamped to the pontoon by tightening the winged bolts. These tighten down at 45-degrees to the horizontal, pulling the clamp 2, hard up against the wooden member at the side of the pontoon, whilst pulling the spring-housing 1, down onto the pontoon planking, and against the raised edge of the pontoon structure.This provides two main functions as follows:- (i) the spring-housing 1, is able to resist theJong Lti Ldl torque created by the torque-arm 3, when in use.

(ii) the spring-housing 1, is able to resist the smaller lateral torque ftom the torque-arm 3, caused by the boat attachment 7, not being perfectly in-line with the plane of movement of the end of the torque-arm 3. This happens when the craft ranges up and down the pontoon, due to mooring lines (springs) not being tight.

The torque-arm 3, see FIG. 1, screws into a rotating drum la, see FIG. 2 and FIG. 5, contained within the spring-housing 1. The latter also contains two powerfW torsion springs le, FIG. 5, acting directly on the rotating drum la, which is provided with a mechanical stop 1c, such that with the connecting -arm 5 disconnected, the attached torque-arm 3 is positioned at about 20 degrees from the vertical, sloping towards the craft, as depicted in FIG. 10 (i), and held by pre-load spring action hard against this stop. in this way, the end of the torque-arm 3 does not overhang the edge of the pontoon, and is thus prevented from damaging the craft prior to connection of the connecting- arm 5. As shown in FIG. 5, the rotating drum la, is located within the spring-housing 1, by two end-plates 1b, which bolt to the sides of the housing, and allow the rotating drum la, to rotate about its two end bearings, featuring self-lubricating bushes Id. Each endplate I b, incorporates a hole on the inside, in order to locate and anchor one end of its associated torsion spring, and a large nut on the outside, for pre- loading its spring to the design torque, prior to bolting the end-plate 1b, to the spring -housing 1, using six bolts. These six bolts, engage with any six of eighteen threaded holes on each side of the spring - housing 1, thus enabling the spring pre-load torque to be set to within the equivalent of 20-degrees of axial rotation.

The base of the torque-arm 3, where it connects with the rotating-drum la, must be sufficiently strong to withstand the considerable torque forces produced, and accordingly, FIG. 3 shows the torque-arm 3 having a tapered form. The torque-arm 3, transfers the high spring force available at the rotating drum la, to an appropriate force at approximately the same elevation as the boat attachment 7, see FIG. 1. It is envisaged that a range of different torque-arm 3 lengths will be required, to suit a range of different gunwhale heights, such that the connecting-arm 5, when connected, is always essentially horizontal. Two flats 3a, see FIG. 3, positioned near the narrow end of the torque-arm 3, enable it to be tightly screwed into the rotating drum la. The sliding-plug 4, see FIG. 3 (i), is permanently connected to the top of the torque-arm 3, via a connecting piece 4a, the end bearings of which, form a preferred design of universal- joint employing corrosion free self-lubricating bushes and washers. The universal- joint provides for relative movement between the craft and pontoon, and the changing angle this causes, between the torquearm 3, and connecting-arm 5.

Alternatively, this universal- joint may be replaced by a corrosion resistant ball-j oint, as shown in FIG. 3 (ii). The sliding-plug 4, see FIG. 3, is comprised of a narrow section which slides into the conical guide 5a of the connecting-arm 5, see FIG. 4. The shoulder of the slidingplug 4, provided by the wider section, see FIG. 3, butts up against the end of the connecting-arm 5, and prevents any further movement. The sliding-plug 4, is the means of connection and disconnection between the torque-arm 3 and the connectingarm 5. Additionally, the sliding-plug 4, will automatically disengage itself from the connecting-arm 5, in the unlikely event of the craft losing her mooring lines, or in the even more unlikely event of an owner making way before disconnecting the invention. In this way, the craft's hull/gunwhale is protected from experiencing tension forces, for which it may not have been designed.

The connecting-arm 5, see FIG. 4, transfers the protective push provided by the torquearm 3, to the craft. Its length must be such, that during normal calm conditions, with the craft's conventional fenders held approximately 150 m.m. away from the pontoon, the torque-arm 3 is approximately 15-degrees from the vertical, away from the craft. This ensures that the torque-arm 3, is normally positioned in the middle of its effective range, with ample available movement in either direction. A threaded rod section of the connecting-arm 5, enables adjustment in length to be made, to facilitate positioning the torque-arm 3 normally 15-degrees from the vertical, away from the craft, without having to resort to undue adjustment of the crafts mooring lines. A conical guide 5a, is connected to one end of the connecting-arm 5, which facilitates entry of the slidingplug 4, whilst simultaneously forming a guard, to prevent entrapment of fingers when the sliding-plug 4, is being inserted into the connecting-arm 5. The connecting-arm 5, is removably secured to the craft, at the boat attachment 7, via a spigot 6, see FIG. 4 (i), and FIG. 7. The spigot 6, in conjunction with its pinned connection to the connecting-arm 5, and the boat attachment 7, together have the following design features:- (i) forms a second universal-joint to provide for vertical and horizontal movement of the craft, relative to the pontoon.

(ii) allows easy single-handed connection and disconnection of the connecting-arm 5, to and from the craft, to be made whilst standing on the pontoon.

(iii) automatically captures/locks the connecting-arm 5, to the boat attachment 7, without the need for additional parts, and without the need to board the craft.

The spigot pin 6b, engages with a self-lubricating bush 7c, via a conical guide 7d, in the boat attachment 7, see FIG. 6. A key 7a, prevents full entry of the spigot pin 6b, unless the spigot key 6a, see FIG. 4 and FIG. 7, is above 45-degrees to the horizontal. Since the spigot 6, is an integral part of the connecting-arm 5, this means that the conical guide end of the connecting-arm 5, must be raised until the connecting-arm 5, is 45degrees to the horizontal. Only then, will the spigot pin 6b, fully engage with the boat attachment 7. Following engagement of the full length of the spigot pin 6b, with the boat attachment 7, the connectingarm 5, may then be lowered nearer to the horizontal position, whereupon the spigot key 6a, engages with the key 7a, thereby making the spigot 6, and therefore the connecting-arm 5, captive with the boat attachment 7. Only when the conical guide end of the connecting-arm 5, is again raised 45-degrees above the horizontal, can the spigot 6, and hence the attached connecting-arm 5, be disengaged from the boat attachment 7. A cam 7b, on the boat attachment 7, aligns with the face of the spigot key 6a, when the spigot pin 6b, is fully home, and prevents any excessive bending moment on the spigot pin 6b, due to abnormally high compressive forces via the connecting-arm 5. Possible bending moments on the spigot pin 6b, caused by tension forces in the connecting-arm 5, are prevented by the automatic withdrawal of the slidingplug 4, FIG. 3, from the connecting-arm 5, FIG. 4. In the event that the sliding-plug 4, detaches whilst in use, from the connecting-arm 5, the latter will hang down the side of the hull, and still be retained by the boat attachment 7. A "rubber-doughnut" 5b, FIG. 4, affixed to the connecting-arm 5, protects the craft's hull from damage, should this eventuality ever happen.

The boat attachment 7, FIG. 1, permanently attaches to the gunwhale of the craft, approximately amidships, and provides for ready attachment and detachment of the connecting-arm 5, using the spigot 6. Ideally, the boat attachment 7, should be throughbolted to the craft's gunwhale, as shown in FIG. 6, using two bolts in order to prevent any twisting movement. FIG. 6 also shows the use of a hard rubber distance piece under the boat attachment 7, to protect the craft's hull, and a pressure plate on the inside of the hull, to distribute the connection loads caused by the mounting nuts. A boat attachment 7, will be required to be mounted on both port and starboard gunwhales, if a craft is to be moored both stem to and stem to. Alternatively, the preferred boat attachment 7, FIG. 6, and spigot 6, FIG. 7, combination, could take the form of a releasable ball-joint, the ball / boat attachment 8, of which is shown in FIG. 8, and the releasable cup 6d, shown in FIG. 4 (ii).

A removable foot lever 9, FIG.9, engages with the tapered torque-arm 3, and grips the latter just above the spring housing 1. Foot pressure on the end of the foot lever 9, enables the torque-arm 3, to be easily controlled and positioned, prior to inserting the sliding-plug 4, into the connecting-arm 5. A spanner 9a, is incorporated into the top edge of the foot lever 9, which is used to tighten the torque-arm 3, into the rotating drum la, FIG. 5, of the spring unit. Flats 3a, FIG. 3, are provided near the narrow end of the torque-arm 3, for this purpose.

FIG. 10, illustrates the steps required in order to attach the invention to the pontoon and craft, so as to be operable. Illustration (i), shows the spring-housing, attached to the pontoon using the clamp. It also shows the torque-arm, already attached 1 tightened to the spring-housing, the foot-lever 9 connected, and the connecting-arm 5, being positioned at 45-degrees to the horizontal, prior to engagement of the spigot, with the boat attachment. The craft is shown, being held off the pontoon by its conventional fenders.

Illustration (ii), shows the connecting-arm 5, fully engaged with the boat attachment, and foot pressure being applied to the foot lever 9.

Illustration (iii), shows the imminent connection of the sliding-plug 4, with the connecting-arm 5, via the conical guide, whilst controlling the position of the slidingplug 4 with foot pressure on the foot lever 9.

Illustration (iv), shows the sliding-plug 4,. fully connected with the connecting-arm 5, resulting in the torque-arm, pushing the craft's conventional fenders away from the pontoon by distance V. (nominally, about 150 m.m., for any sized craft). This illustration also shows that the connecting-arm 5 length,(in conjunction with the craft's mooring lines), has been adjusted to ensure that in normal cahn conditions the torquearm, is normally 15-degrees from the vertical, away from the craft, and in the middle of its effective range of movement. The illustration also shows that the foot lever 9 has been removed.

To remove the mechanised fender, ready for stowing, the steps described above are carried out in reverse order. Additionally, if required, the torque-arm 3, may be unscrewed from the spring-unit, using the spanner 9a which is integral with the foot lever 9.

1 1

Claims

1. A mechanised fender for marina-based craft, comprising a springactuated device, which pushes the craft away from the pontoon against her mooring lines, thus normally maintaining a gap between the pontoon and the craft's conventional fenders.

2. A mechanised fender as claimed in Claim 1, wherein the spring-actuated device comprises a spring-actuated torque-wri, which connects to the craft via a removable, variable length connecting-arm, and permanently secured boat attachment.

3. A mechanised fender as claimed in Claim 1 or Claim 2, wherein the torque-arm releasably connects with the connecting-ann, via a sliding-plug, in order to provide convenient attachment, with automatic detachment under tension, and via a universal- joint in order to allow for the relative movement between connectingarm and torque-arm.

4. A mechanised fender as claimed in Claim 2 or Claim 3, wherein the connecting- arm releasably connects with the boat attachment via a second universal- joint, in order to allow for relative movement between the connecting-arm and the boat attachment.

5. A mechanised fender as claimed in Claim 2 or Claim 4, wherein the connecting- arm incorporates a screwed rod section, in order to provide both the means for adjusting its length to position the torque-arm normally 15- degrees from the vertical away from the craft, and the means for allowing for twisting movement caused by the crafrs pitching motion.

6. A mechanised fender as claimed in Claim 4, wherein the releasable connection between the connecting-ann and boat attachment, incorporates a guide to enable easy single-handed attachment of the connecting-arm from the pontoon, and which automatically secures the connecting-arm to the boat attachment once the connecimg-arm has been lowered to its nornial working range of movements.

7. A mechanised fender as claimed in Claim 5, wherein the connecting-arm iorporates a conical guide, which provides assistance during entry of the sliding-plug, and also forms a safety guard, to prevent entrapment of fingers before the sliding-plug has made full engagement with the connecting-ann.

8. A mechanised fender as claimed in Claim 2 or Claim 3, wherein in order to provide easy stowage, the torque-arm is releasably secured to the spring unit via a screwed connection, which can be tightened and un-tightened by engaging the spanner section of the foot lever, with two flats provided near the narrow end of the torque-arm.

9. A mechanised fender as claimed in Claim 1 or Claim 2, wherein the springactuated device is releasably clamped to the craft's pontoon.

10. A mechanised fender as claimed in Claim 9, wherein the releasable clamp is an adjustable swinging clamp, which engages with the side of the pontoon structure.

11. A mechanised fender as claimed in Claim 8, wherein the torque-ann screws into a rotating drum controlled by a double torsion spring contained within a springhousing, and with the rotating drum provided with a mechanical stop, such that the pre-loaded torque-arm is constrained from moving greater than 20-degrees passed the vertical, thereby preventing overhang from the edge of the pontoon, and possible damage to the craft, prior to connection of the connecting-arm.

12. A mechanised fender as claimed in Claim 11, wherein the springactuated torquearm is provided with sufficient travel, such as to be comfortably in excess of that required when the craft is pressed hard against her conventional fenders during storm conditions, thereby preventing unnecessarily high point-loading forces on the crafts hull.

13. A mechanised fender, substantially as described herein, with reference to Figures 1 to 10 of the accompanying drawing.

13. A mechanised fender as claimed in any preceding claim, wherein a removable foot lever connects to the base of the torque-arm, thereby enabling the high spring force acting on the torque-arm to be easily controlled and the torque-arm to be---accurately positioned, whilst simultaneously inserting the sliding-plug into the guide at the end of the moving connecting-arm.

14. A mechanised fender, substantially as described herein, with reference to Figures 1 to 10 of the accompanying drawing.

ok, k t CLAIMS 1. A mechanised fender for marina-based craft, which will supplement a craft's existing pontoon mooring system of restraining lines and conventional fenders, and which will normally maintain a gap between the pontoon and the craft's conventional fenders, by providing a biasing force on the craft only in a direction substantially away from the pontoon, such that in use, the craft is normally biased against her restraining lines, the fender comprising a spring-actuated device controlling a torque-arm which connects to the craft via a variable length connecting-arm, one end of which, in use, is secured to the craft by attachment means and the other end of which is releasably / removably connected to the torque-arm, and means for attaching the spring-actuated device, in use, to the pontoon.

2. A mechanised fender as claimed in Claim 1, wherein the biasing force is restricted such that it may be temporarily overcome by the combined forces resulting from the action of adverse weather conditions on the craft, and wherein the springactuated torque-arm is provided with sufficient rangeability of travel, such that the torque-arm can never become the limiting factor on the craft's movements, thereby allowing the craft to be temporarily pressed hard against her conventional fenders during adverse weather conditions, thus preventing the mechanised fender from causing potential dangerously high point-loading forces to act on the craft's hull.

3. A mechanised fender as claimed in Claim 1 or Claim 2, wherein the torque-arm releasably connects with the connecting-arm via a universaljoint in order to allow for the relative movement between the connecting-arm and torque-arm, and via a sliding-plug, in order to provide convenient attachment means, and to provide automatic detachment under tension, thereby preventing possibly dangerous tension forces to be exerted on the craft's hull, for example, in the event that the craft should accidentally break loose from her mooring.

4. A mechanised fender as claimed in Claim 1 or Claim 3, wherein the connecting- arm releasably connects with the attachment means via a second universal- joint, in order to allow for relative movement between the connecting-arm and the attachment means.

5. A mechanised fender as claimed in Claim 1 or Claim 3, wherein the connecting- arm incorporates a screwed rod section, in order t6 provide both the means for adjusting its length to position the torque-arm normally approximately 15-degrees from the vertical away from the craft, and the means for allowing for twisting movement caused by the crafVs pitching motion.

6. A mechanised fender as claimed in Claim.4, wherein the releasable connection between the connecting-arm and attachment means, incorporates a guide to enable easy single-handed attachment of the connecting-arm from the pontoon, and which automatically secures the connecting-arm to the attachment means, once the connecting-ann has been lowered to its normal working range of movements.

7. A mechanised fender as claimed in Claim 5, wherein the connecting-arm incorporates a conical guide, which provides assistance during entry of the sliding-plug, and also forms a safety guard, to prevent entrapment of flingers before the sliding-plug has made full engagement with the connecting-arm.

8. A mechanised fender as claimed in Claim 1, wherein the Pontoon comprises planking, and wherein the means for attaching the spring-actuated device, in use, to the pontoon, is an adjustable swinging clamp, which engages with the structure of the pontoon, and releasably clamps the spring- actuated device to the upper surface of the pontoon planking.

9. A mechanised fender as claimed in Claim 1, wherein the pontoon comprises planking, and wherein the means for attaching the spring-actuated device, in use, to the pontoon, comprises nuts and bolts which permanently secure the springactuated device to the structure of the pontoon, whilst positioning the springactuated device immediately below the pontoon planking, the latter having a slot, to cater for the torque-arm and its movement.

10. A mechanised fender as claimed in Claim 2 or Claim 3, wherein the torque-arm screws into a rotating drum controlled by a double torsion spring contained within a spring-housing, and with the rotating drum provided with a mechanical stop, such that the pre-loaded torque-arm is constrained from moving greater than 20degrees passed the vertical, thereby preventing significant overhang from the edge of the pontoon, and possible damage to the craft, prior to connection of the connecting-arm.

11. A mechanised fender as claimed in Claim 7, wherein a removable foot lever connects to the base of the torque-arm, thereby enabling the high spring force acting on the torque-arm to be easily controlled and the torque-arm to be accurately positioned, whilst simultaneously inserting the sliding- plug into the conical guide at the end of the connecting-arm.

12. - A mechanised fender as claimed in Claim 10, wherein in order to provide easy stowage, the torque-arm is releasably secured via a screwed connection, which can be tightened and un-tightened by engaging a spanner section of the foot lever, with two flats provided near the narrow end of the torque-ann.