BACKGROUND ART Traditionally, ladders for use in boarding marine vessels have been constructed of simple rectangular wood, metal or plastic treads supported in a planar arrangement by ropes. These ladders were usually attached to a vessel by tying the rope to the vessel or by using a general purpose hook.

These ladders suffered from several disadvantages. First, if the ladder was dropped into water, it usually sank, making it difficult, if not impossible, to recover the ladder.

Secondly, if the ladder was attached to the vessel by tying the rope directly to the vessel, it could be detached accidentally, deliberately or through wear. Similarly, if the ladder was attached to the vessel by a general purpose hook, the hook could be detached from the vessel either accidentally or deliberately, endangering users climbing the ladder.

Thirdly, in use, at least an upper part of the ladder rested against the generally vertical portion of the outerside or hull of the vessel that the user wished to board. As the ladder was constructed from a plurality of treads hanging by ropes under gravity, the treads rested directly against the generally vertical portion of the hull of the vessel. In use, when the user's hands or feet were on the treads resting against the generally vertical portion of the hull, the hands or feet would also come into contact with the hull. This limited the purchase or grip a user could gain on the treads. Further, if the attached ladder moved away from the hull of the vessel and then returned to the hull, say, by the swell of the sea causing the vessel to sway, the user's hands could be trapped between the tread and the hull, causing injury to the hands. In

addition, if the ladder suddenly returned to the hull, the force of the impact could push the user's hands or feet off the treads, causing the user to slip or fall from the ladder.

A further problem with these ladders was that when positioning the ladder for use by attaching the ladder to the gunwale or to a part of the vessel located above the user's head, a pole had to be fitted and the ladder elevated.

The ladder often became unstable when hoisted a significant distance, making the ladder dangerous and difficult to position and limiting the utility of the ladder.

It is a preferred object of the present invention to provide a ladder which is buoyant or at least temporarily floats when dropped into water.

It is another preferred object of the present invention to provide a ladder which cannot be accidentally or deliberately detached from a vessel when in use.

It is a further preferred object of the present invention to provide a ladder with treads remote from the surface against which the ladder is resting.

It is yet another preferred object of the present invention to provide a method for safely and easily attaching a ladder to a vessel at a point above the user's head.

SUMMARY OF THE INVENTION According to one aspect of the invention there is provided a ladder for boarding a marine vessel, comprising:- a plurality of spaced apart treads; first and second elongate flexible members between which are connected the spaced apart treads; attachment means for attaching the ladder to the vessel, and spacer members connected to at least some of the treads and extending

outwardly therefrom so that, in use, the spacer members contact the outer side of the vessel but the treads remain remotely located from the vessel outer side, thereby preventing the feet or hands of a user of the ladder coming into contact with the outer side of the vessel.

According to another aspect of the invention there is provided a ladder for boarding a marine vessel, comprising:- a plurality of spaced apart treads; first and second elongate flexible members between which are connected the spaced apart treads; and attachment means for attaching the ladder to the vessel, wherein the attachment means includes first and second hook members interconnected by at least one bar, each hook member having teeth for preventing movement of the attachment means when the ladder is attached to the vessel, and wherein, in use, the attachment means cooperates with the vessel such that the attachment means cannot be detached from the vessel.

According to a further aspect of the invention there is provided a ladder for boarding a marine vessel, comprising:- (a) a plurality of spaced apart rungs, each rung comprising:- (i) at least two support portions, each support portion having a proximal end and a distal end; and (ii) a tread portion, wherein at least one support portion is adapted to be connected to each end of the tread portion and wherein the tread portion is positioned intermediate the proximal and distal ends of the support portions; and (b) at least two elongate flexible members, wherein at least one elongate flexible member is adapted to be attached to each end of each rung, and wherein the distal ends of the support portions are adapted to contact the outer

side of the vessel such that the tread portions remain remotely located from the vessel outer side, thereby preventing the feet or hands of a user of the ladder coming into contact with the outer side of the vessel.

According to another aspect of the invention there is provided a method for using a ladder to board a marine vessel, comprising:- attaching an elongated pole to an attachment means of the ladder ; positioning the attachment means on part of the vessel by use of the elongated pole ; locking the attachment means to the vessel by applying a downward force to a plurality of cables attached to the attachment means or by applying a downward force to the ladder, and climbing the ladder.

BRIEF DESCRIPTION OF THE DRAWINGS Fig. 1 is a front view of a ladder according to a first preferred embodiment of the invention, Fig. 2 is a side view of the ladder of Fig. 1, Fig. 3 is a front view of an extension portion for the ladder of Fig. 1, Fig. 4 is a side view of the extension portion of Fig. 3, Fig. 5 is a front perspective view of the ladder of Fig. 1, Fig. 6 is a front view of a tread used in the ladder of Fig. 1, Fig. 7 is a front view of an attachment means used in the ladder of Fig. 1, Fig. 8 is a side view of the attachment means of Fig. 7, Fig. 9 is a front perspective view of the attachment means of Fig. 7 with connecting links fitted thereto, Fig. 10 is a view showing a typical example of the use of the ladder of Fig. 1 to board a marine vessel,

Fig. 11 is a front view of an extension pole for use with the ladder of Fig. 1 according to another aspect of the invention, Fig. 12 is a side view of the extension pole of Fig. 11, Fig. 13 is a front view of a ladder according to another embodiment of the invention, Fig. 14 is a side view of the ladder of Fig. 13, Fig. 15 is a front perspective view of the ladder of Fig. 13 excluding the female member, Fig. 16 is a side view of an extension pole for use with the ladder of Fig.

13 according to another aspect of the invention, Fig. 17 is a side view of the extension pole of Fig. 16 excluding the male attachment means, and Fig. 18 is a side view of a clip for use with the ladder of Fig 13 according to another aspect of the invention.

DETAILED DESCRIPTION OF THE DRAWINGS The ladder 100 shown in Figs. 1 to 10 has a plurality of spaced apart treads 102, and two elongate flexible members 104 and 106 between which are connected the spaced apart treads 102. In this embodiment, the treads 102 (also known as rungs) are made of glass reinforced epoxy resin having a roughened surface for improved grip arising from aluminium oxide embedded therein, and the elongate flexible members 104 and 106 are ropes made of polypropylene.

Disc shaped, spacer members 108 are connected to at least some of the treads 102 and extend outwardly therefrom as particularly shown in Fig. 2. In use, the spacer members 108 may contact the vessel outer side or hull surface but the treads 102 remain remotely located from the vessel surface, as shown I

particularly in Fig. 10, such that the user can place their hands or feet normally on the treads 102 without their hands or feet coming into contact with the vessel surface.

The elongate flexible members 104,106 support the treads 102 by use of knots 109, as particularly shown in Fig. 2. The knots 108 prevent the treads 102 from moving relative to the elongate flexible members 104,106 and thus maintain the treads 102 at positions spaced apart from one another.

The embodiment of the ladder 100 shown in Figs. 1 to 10 also shows an attachment means 112 for attaching the ladder to a vessel. The attachment means 112, comprises two hook members 114 made of black nylon. Each hook member has a forward downwardly projecting portion 116, an intermediate horizontal portion 118, and a rearward vertical portion 120. Two spacing bars 122 interconnect the two hook members 114, giving the attachment means additional strength. Each hook member 114 has a plurality of teeth 124 for preventing movement of the attachment means 112 when the ladder 100 is attached to a vessel.

In use, the attachment means 112 is brought into locking contact with the vessel, say, with a gunwale at the edge of the deck of a vessel. The rearward vertical portion 120 firmly contacts the back of the gunwale via the teeth 124 and so prevents the attachment means 112 from sliding off the vessel.

Further, when the user climbs the ladder 100, the user's weight is transferred to the rearward vertical portion 120, as that portion 120 is the part of the attachment means 112 that hooks onto the vessel. When weight is transferred to the rearward vertical portion 120, the forces acting on the attachment means 112 may cause the attachment means to rotate so that the lower part of the portion 116 contacts the vessel surface. The rotational forces

acting on the attachment means 112 further cause it to be held with force against the vessel surface until the user completes climbing the ladder.

The combination of the effect of the teeth 124, the force on the rearward vertical portion 120 as a result of the weight of the user, and the rotational force on the attachment means 112 locks the attachment means 112 in place and prevents it from being removed from the vessel by a hostile crew.

The attachment means 112 also comprises handle apertures 140 formed through respective intermediate horizontal portions 118. These handle apertures 140 are designed to assist the user to lift the ladder from the vessel after use.

A connecting link 142 (of the type that opens by a screw gate) is fitted to a respective hole 144 formed through a lower portion of a hook member 114 and connects to a rope thimble 146 that is, in turn, linked to spliced portions 148 of the rope 104,106. The unspliced length of the rope 104,106 is of such a diameter that it fits snugly through transverse holes formed adjacent the ends of each tread 102.

An extension pole 150 is shown in Figs. 11 and 12 for use in hoisting the attachment means 112 upwardly onto the vessel. The pole 150 has a rod portion 152, a trident head portion 154, and an adjustable lock portion 156 for interconnecting the rod portion 152 with the trident head portion 154. The trident head portion 154 has a central prong 158 that is c-axial with the rod portion 152, and has two opposed end prongs 160,162 that are upwardly inclined at an angle away from the central prong 158. The end prongs 160, 162 and the central prong 158 define a converging arrangement for locating the uppermost spacing bar of the attachment means therebetween when the ladder is being deployed for use in boarding and being retrieved after use. The extension pole 150 is telescopically extendable to suit varying gunwale heights

by having a neck shaft 166 of the trident head portion engaging telescopically within the rod portion 152. The lock portion 156 has a locking nut 168 that compresses a slitted collar 170 that encloses around and tightly grips the interengaging portions of neck shaft 166 and rod portion 152.

The ladder 10 shown in Figs. 13 to 15 has a plurality of spaced apart rungs 12 and two elongate flexible members 14 and 16. Each rung 12 comprises a tread portion 18 and two support portions 20 and 22. The support portions 20 and 22 are attached to opposite ends of the tread portion 18 and are substantially perpendicular to the tread portion 18. Each support portion 20,22 has an end 24 proximal the user and an end 28 distal the user. In use, the distal ends 28 may contact the vessel outer side or hull surface. The tread portion 18 is spaced apart from the distal ends 28, as shown particularly in Fig.

15, such that the user can place their hands or feet normally on the tread portion 18 without their hands or feet coming into contact with the vessel surface.

The elongate flexible members 14,16 are connected to the support portions 20 and 22 as shown in Figs 13 to 15. The elongate flexible members 14,16 support the rungs 12 by use of knots 30, as particularly shown in Fig 14.

The knots 30 prevent the rungs 12 from moving relative to the elongate flexible members 14,16 and thus maintain the rungs 12 at positions spaced apart from one another.

The embodiment of the ladder shown in Figs. 13 to 15 also shows an attachment means 32 for attaching the ladder to a vessel. The attachment means 32 comprises two hook members 34. Each hook member 34 has a forward vertical portion 36, an intermediate horizontal portion 38, and a rearward vertical portion 40. A bar 42 interconnects the two hook members 34, giving the attachment means 32 additional strength.

In use, the attachment means 32 is brought into locking contact with the vessel, say, with a gunwale at the edge of the deck of a vessel. The rearward vertical portion 40 contacts the back of the gunwale and so prevents the attachment means 32 from sliding off the vessel.

Further, when the user climbs the ladder 10, the user's weight is transferred to the rearward vertical portion 40, as that portion 40 is the only part of the attachment means 32 that contacts the vessel. When weight is transferred to the rearward vertical portion 40, the forces acting on the f attachment means 32 may cause the attachment means to rotate so that the bar 42 contacts the vessel surface. The rotational forces acting on the attachment means 32 further cause the bar 42 to be held with force against the vessel surface until the user completes climbing the ladder.

The combination of the force on the rearward vertical portion 40 as a result of the weight of the user and the rotational force on the bar 42 locks the attachment means 32 in place and prevents the attachment means 32 from being removed from the vessel by a hostile crew.

The attachment means 32 also comprises a bar 44 connecting the hook portions 34. This bar 44 gives the attachment means 32 additional strength and acts as a final rung for climbing by the user.

The attachment means 32 also comprises handles 46. The handles 46 are attached to the forward vertical portions 36 and extend therefrom as shown particularly in Fig 15. These handles 46 are designed to assist the user to mount the vessel from the ladder. Cables can also be attached to the handles 46. In use, the cables can be pulled downwardly by persons assisting the user to climb the ladder, whereby the force so exerted further locks the attachment means 32 in place and further ensures that the ladder cannot be removed from the vessel by a hostile crew prior to the user mounting the ladder.

The attachment means 32 also comprises a female member 48, as shown in Figs 13 and 14. This member 48 is designed to receive a male member 50 attached to the end of an elongated pole 52 as shown in Fig 16.

The male member 50 and female member 48 are formed such that, in use, there is an interference fit or at least frictional mating between the male member 50 and female member 48 such that they cannot be inadvertently disconnected.

The pole 52 comprises an outer sleeve 54 and an inner tube 56 slidably insertable within the outer sleeve 54. The outer sleeve 54 and the inner tube 56 each have at least one hole drilled therethrough. In use, the inner tube 56 is moved relative to the outer sleeve 54 until the approximate desired height of the pole is reached, whereupon the position of the outer sleeve 54 is adjusted relative to the inner tube 56 until a hole in the outer sleeve 54 is superimposed with a hole in the inner tube 56. Once the holes are superimposed, a clip 58 (as shown in Fig. 18) is inserted into the superimposed holes, locking the outer sleeve 54 and the inner tube 56 in place, securely fixing the height of the pole.

In use, the pole 52 is extended to the appropriate height, the holes superimposed and the clip 58 inserted to lock the pole 52 at the desired height.

The male member 50 attached to the end of the pole 52 is inserted into the female member 48 on the attachment means 32. The user then lifts the ladder 10 above their head by use of the pole 52. The user positions the attachment means 32 so that the rearward vertical portion 40 contacts the back of the gunwale of the vessel. The male member 50 is then removed from the female member 48 by downward movement of the pole 52.

The attachment means 32 is then locked in place by either a user climbing the ladder and thereby putting weight on the ladder so as to bring the bar 42 into contact with the surface of the vessel, or by persons assisting the

user pulling down on cables attached to the handles 46 so as to bring the bar 42 into contact with the surface of the vessel, or by both of the abovementioned approaches.

The clip 58 has a fine cable (not shown) attached thereto such that the clip 58 can be removed from the holes by pulling the cable. In addition the cable is attached to the pole 52 so that the clip 58 cannot be lost.

The pole 52 is preferably constructed from aluminium tube such that, if the pole were dropped into water, it would temporarily float.

The rungs 12, elongate flexible members 14 and 16 and attachment means 32 are all constructed from light weight materials. The rungs 12 are, preferably, constructed from a combination of fibreglass and polyester resin.

The elongate flexible members 14 and 16 are constructed of materials such a polypropylene. The attachment means 32 is constructed of welded aluminium tube. The combination of components constructed in this way produces a ladder which will temporarily float when placed in water.

Although each ladder 100 and 10 has been described as having specific features adapted for a particular purpose, it would be apparent to a person skilled in the art that the features of any one of the ladders can be substituted for features of the other ladder and retain the functional advantages inherent in the structure and operation of the ladder.

It would also be apparent to a person skilled in the art that, although the ladders are described in use on marine vessels, these ladders could also be used on land, for example, in climbing buildings.

Various modifications may be made in details of design and construction without departing from the scope and ambit of the invention.