Abstract:
A separation and guidance structure comprises an arm having an inner end with a crosspiece secured in use to a pontoon or the like, and an outer end provided with fenders extending above and beyond the end of the arm. Flotation is provided to support the outer end of the arm, and may be in the form of a flotation member or be provided by the fenders. In use a number of such structures are secured in parallel to a pontoon or dock to form a berthing system.

Description:
FIELD OF THE INVENTION 
     This invention relates to berthing systems and is particularly, but not exclusively, applicable to the berthing of small craft such as sail and power yachts in marinas and the like. 
     BACKGROUND 
     In some sailing areas, such as the United Kingdom, a marina has floating pontoons from which extend floating fingers. Generally the fingers are spaced apart such that two craft can occupy the space between, each craft being adjacent and attached to a finger. Generally the fingers include decking allowing users to walk on the finger and access the attached craft, flotation units provided beneath the decking, and mooring points allowing the securing of ropes to attach the adjacent craft. To enter the berth, the user has to approach parallel to the pontoon and then make a right-angle turn into the berth. This manoeuvre can present some difficulty, especially where there is a strong wind or tidal current across the berth, or if the user lacks experience, and it is quite common for a craft entering or leaving a berth to make contact with the neighbouring vessel or with the corner of the finger. Such contact is frequently sufficiently heavy to case damage. Also, in an attempt to minimise such occurrences marina operators may increase the spacing between fingers; this makes maneuvering simpler but is wasteful of valuable mooring space. 
     In other sailing waters, such as the Mediterranean, small craft commonly berth bows-to or stern-to a floating pontoon or a fixed dock. In this case, the craft must approach at right angles to the pontoon or dock into a clear space between vessels already berthed. The leading end (bows or stern) must be made fast to the pontoon or dock, and the opposite end is secured to permanent mooring ropes with pick-up buoys, or by dropping an anchor during the approach. Here again, the manoeuvre can be difficult in cross-wind or cross-tide conditions, especially if made into a space which is just sufficiently wide, and damaging collisions can occur. 
     It will be appreciated that floating pontoons are generally used wherever there is a significant tidal range, while fixed docks are commonly used where tidal range is small, e.g. the Mediterranean or the Baltic. For simplicity, the term “pontoon” will be used herein to include both. 
     SUMMARY OF THE INVENTION 
     The present invention seeks to improve upon these practices, and to provide a berthing system which is safer in use and which potentially can increase the berthing density. 
     Accordingly, the invention provides a separation and guidance structure for use in a berthing system, the structure comprising a link arm, attachment means for connection to a pontoon at a first end of the link arm, a flotation device toward a second end of the link arm, and at least one first fender provided at the second end of the link arm, at least a portion of the first fender extending above the link arm and beyond the end of the link arm so as to serve as a guidance means for a boat approaching the berthing system. 
     From another aspect, the invention provides a berthing system comprising a pontoon or dock and a plurality of such separation and guidance structures extending from the pontoon or dock. 
     Preferred features and advantages of the invention will be apparent from the claims and from the following description. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       Embodiments of the invention will now be described, by way of example, with reference to the drawings, in which: 
         FIG. 1  is a schematic plan view of a prior art berthing system; 
         FIG. 2  is a similar view showing a first embodiment of the present invention; 
         FIG. 3  is a perspective view to an enlarged scale of a separation and guidance structure used in  FIG. 2 ; 
         FIG. 3A  shows part of the embodiment of  FIGS. 2 and 3  in more detail; 
         FIG. 4  is a partial perspective view illustrating a modification of  FIG. 3 ; 
         FIG. 5  shows a row of berths without fingers; 
         FIG. 6  shows an arrangement similar to  FIG. 5  but with angled berths; and 
         FIG. 7  is a perspective view of a separations and guidance structure suitable for larger vessels. 
     
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENTS 
       FIG. 1  shows a conventional berthing arrangement, with a pontoon  10  and fingers  12  and  14 . A vessel  16  is berthed at the finger  12 , and another vessel  18  is approaching the finger  14 . 
     Referring to  FIGS. 2 and 3 , in a first embodiment of the invention a separating and guidance structure generally designated at  20  is positioned between the fingers  12 ,  14 . The structure  20  comprises a rigid arm  22  secured at its inboard end to a crosspiece  24  serving as a connection member, and braced by bracing members or struts  26 . The crosspiece  24  and struts  26  together serve as a mounting bracket for connection to the pontoon and adapted to provide resistance to lateral forces. 
     The crosspiece  24  is secured to the pontoon  10 , for example by bolting, preferably with rubber buffers shown diagrammatically at  28  ( FIG. 2 ) interposed between the crosspiece  24  and the pontoon  10  to act as resilient dampers.  FIG. 3A  shows one form of buffer arrangement in more detail. The crosspiece  24  is secured to the pontoon  10  by bolts such as  21  passing through aligned apertures in the crosspiece  24  and a structural member  23  of the pontoon, and in resilient blocks  25  disposed on either side of the member  23 . A washer or pressure plate  27  may be disposed between the head of the bolt  21  and the adjacent resilient block  25 . Thus, resilient damping will be applied to axial movement of the structure  20  in either direction. 
     In exposed locations it may be preferred to provide a hinge arrangement between the arm and the pontoon, particularly a horizontal axis hinge allowing the arm to rotate in a vertical plane to accommodate wave motion. This may be useful in situations where the berthing system is only used in fair weather, but must itself survive severe weather. 
     Reverting to  FIG. 3 , the outboard end of the arm  22  carries a pair of cylindrical fenders  30  and  32  disposed one above and one below the arm  22 . The fenders  30  and  32  are mounted on a vertical shaft  34  which is mounted for rotation on the arm  22 . The lower end of the shaft  34  also carries a flotation member  36 . The fenders  30  and  32  are dimensioned and positioned to extend beyond the sides and end of the arm  22 . 
     Thus, the structure  20  is supported between the two fingers  12  and  14  and acts to separate craft berthed at the fingers. The rotatable fenders  30  and  32  assist craft entering and leaving the berths by providing a non-damaging surface against which the craft can bear; that is, the fenders can be used as a turning dolphin. The structure  20  also allows a berthed craft to be secured by warps on both sides, not just to the finger. 
     The arm  22  has a resilient fendering strip  38  on each side, and a central cleat  40 . Guidance lights  42  are mounted along the upper surface of the arm  22 , and an identification light  44  is mounted at the top of the shaft  34 . The lights  42  and  44  may suitably be LEDs, and can be powered by shore power or, conveniently, by an independent solar panel (not shown). By providing the guidance lights  42  at regular intervals along the arm  22 , the user is assisted in judging speed and location within the berth. 
     If the fenders  30  and  32  have sufficient flotation, the flotation member  36  may be dispensed with, the lower fender  32  acting also as flotation member. This arrangement is shown in  FIG. 4 . The fenders  30 ,  32  may suitably be hollow plastic moulding, foam-filled plastic mouldings, or solid foam, in each case with suitable metalwork secured or cast in the centre. 
     Instead of the shaft  34  being rotatable on the arm  22 , it may be rigid with the arm  22 , for example being fastened to the arm with a screw clamp, with the fenders being rotatable on the shaft. 
     In situations where stern-to or bows-to berthing is acceptable, a series of structures  22  may be used without intervening fingers, as illustrated in  FIG. 5 . This can increase berthing density by 18% or more compared with finger berthing.  FIG. 5  also shows the bracing struts  26  covered by a deck  46  which can provide storage or trolley parking. 
       FIG. 6  shows an arrangement similar to  FIG. 5  but with the structures  20  disposed at an angle to the pontoon  10 , in this example at an angle of 30°. Many users will find it easier to enter and leave a berth angled in this manner, and it also allows the lane width between pontoons to be reduced. Other oblique angles are possible, for example the angle may be between 15° and 45°. 
     The foregoing embodiments are suitable for berthing vessels up to about 15 meters LOA. For larger craft the arrangement shown in  FIG. 7  may be used. Here the structure  20  comprises a composite arm  22 A formed by spaced beams  48  in a V-formation and joined by cross-braces  50 . In addition to the outboard fenders  30  and  32 , a further pair of rotatable cylindrical fenders  50 ,  52  is provided at an intermediate location to give additional buoyancy and also to provide further guidance to a vessel entering or leaving the berth. 
     The composite arm  22 A of  FIG. 7  is at an inclined angle to the pontoon, but it will be apparent that a right-angle version is equally possible. 
     Two or more rotatable fenders per arm may be used on any size of arm to provide sufficient guidance and fendering to allow the vessel to dispense with on-board fenders hung over the vessel side. 
     Other modifications may be made to the foregoing embodiments within the scope of the claims. For example, it would be possible (although less desirable) to provide outboard fendering which is non-rotatable so long as it covers the outboard end of the arm. Also, the outboard fendering and the flotation of the arm could be divorced, there being no need for the flotation to be at the outboard end. 
     The invention may be applied to craft other than pleasure craft such as patrol boats, lifeboats, customs launches and pilot boats, typically up to 33 meters length. 
     As well as in fixed marinas, the invention may be used as part of a mobile marina system that may be utilised to temporarily expand or establish marina facilities to meet regatta, boat show, seasonal or other temporary requirements. The structures may be transported by road, rail or sea, with or without additional pontoon or dock units. If transported on a ship, the ship itself may provide the dockside facilities, pontoons may be attached to the ship, and the separation and guidance structures may be attached to the pontoons. 
     The invention thus provides a berthing system which gives improved safety, ease of berthing and unberthing, and in certain embodiments a greater density of berths in a given water area.