The present invention relates a variable beam vessel. More particularly, the present invention relates to, but is not limited to, a vessel having a main hull and two floats on opposite sides of the main hull, the floats being retractable towards the main hull.
Catamarans and trimarans have become popular vessels due to their efficient movement through the water, low draft (the vertical distance between the waterline and bottom of the hull) and a wide beam that provides greater stability than a monohull vessel.
While the wide beam is useful for stability it can also be problematic for multi-hulled vessels. This is particularly the case for trimarans, which have a central main hull and two floats disposed symmetrically on opposite sides of the main hull. The increased width increases the cost of berthing and makes road travel difficult.
Some trimarans have been proposed with retractable stabilizing floats. Some such vessels have floats that pivot aft (i.e. towards the stern), which means they need to incorporate a vertical pivot point at the float. The vertical pivot experiences wear, and is generally considerably weaker than a rigidly fixed arrangement, when faced with consistent loading during use and when transporting the vessel. Other embodiments provide a laterally shifting float arrangement, in which floats that are rigidly fixed to the end of support beams are moved laterally in towards the main hull of the vessel. Such arrangements either lose stability or result in parts of the floats being moved under water that, during normal use, are above the draft level of the floats. Those parts are therefore susceptible to marine growth and degradation.
It would be desirable to overcome or alleviate at least one of the above-described problems, or at least to provide a useful alternative.
The present disclosure provides a variable beam vessel, comprising:
Unless context dictates otherwise, the “main support member” may be referred to as a support beam. This is not to be confused with the beam of a vessel referring to the width at its widest point when viewing from the bow or stern.
The float connection may comprise an abutment formed on a first one of the main support member or the float and located to abut a second one of the main support member and float, to restrict longitudinal relative movement between the main support member and float.
The float connection may comprise a slot on one of the main support member and float and a pin on the other of the main support member and float, the pin sliding along the slot between a first position corresponding to the in-use configuration and a second position corresponding to the stowed configuration. The first position and second position may be at opposite ends of the slot. The slot may be shaped to control relative movement of the float and main support member during movement between the in-use configuration and stowed configuration.
The float connection may further comprise a pivot, the float pivoting on the float end of the main support member between the stowed configuration and in-use configuration.
The pin may be on the float end and the pivot is located distally of the pin. The pin may be one of two pins located on the main support member, and the slot may be one of two slots disposed on opposite sides of the main support member in a channel in the float. The channel may have two opposite end walls and side walls, the end and side walls converging distally of the pivot, each end wall defining a position of the float end of the main support beam when in a respective one of the stowed configuration and in-use configuration.
The actuation system may comprise at least two flexible cord lengths each connected at one end to the float and extending from the float to the main hull, and wherein one cord length moves the float connection assembly to the in-use configuration and another cord length moves the float connection assembly to the stowed configuration. The flexible cord lengths may comprise part of the same cord—e.g. a rope fixed to the float at some point intermediate the ends of the rope, with a length of rope extending from either side of the fixed point.
The vessel may comprise two floats and two float connection assemblies each connecting a respective one of the floats to the main hull. The actuation systems of the two float connection assemblies may be interconnected such that they can be concurrently operated to move the symmetrically between the in-use configuration and stowed configuration.
The hull end of the main support member may be connected to the main hull in the in-use configuration and is disconnected from the main hull in the stowed configuration.
The hull end may disconnect from the main hull to facilitate movement to the stowed configuration. The hull end of the main support beam may elevate above the main hull during movement to the stowed configuration, so that it does not obstruct access along the main hull in the stowed configuration.
The float connection assembly may be configured to maintain a common draft of the float when in both the in-use configuration and the stowed configuration.
The variable beam vessel may further comprise a stabiliser for controlling a position of the main support member relative to the main hull during movement between the in-use configuration and stowed configuration. The stabiliser may comprise a frame extending between the main hull and main support member. The stabiliser may also comprise an alignment member. In such cases, the alignment member and frame maintain a perpendicular alignment between the main support member and longitudinal axis during movement between the stowed configuration and in-use configuration.
The main support member may comprise two spaced support beams each having a respective said float end and respective said hull end.
Embodiments of the present invention will now be described, by way of non-limiting example, by reference to the drawings, in which:
Vessels described herein have a variable beam insofar as the overall width of the vessel can be reduced for docking, or increased for stable travel over water. While the description is given generally in the context of trimarans, it will be understood the present teachings can apply similarly to particular configurations of catamaran, and to multi-hulled vessels in general.
The term “main hull” is used to identify the hull or buoyant body from which a user operates the floats. The term “float” may therefore refer to a buoyant stabilising body such as an outrigger, but may also refer to a hull that is separate from the main hull.
The vessel 100 has an in-use configuration as shown in
The float connection assembly includes a main support member (presently support beam 118), and an actuation system 120 as best seen in
The support beam 118 is embodied by a substantially rigid, unbendable member. In the present context, “substantially rigid”, “unbendable” and other terms refer to the support beam and other components being sufficiently rigid or unbendable to achieve the desired function.
The support beam 118 has a hull end 120 that is connectable to the main hull, and a float end 122 that is connected to the float 104 at a float connection 124 as shown in
The float connection 124, as shown in
It will be appreciated that where an abutment is provided, various arrangements are possible—e.g. the abutment may be on the support beam 118 rather than the float 104.
The following discussion is given with respect to plate 136 and pin 132, but applies equally to plate 142 and pin 140. The float connection 124, particularly slotted plate 136, comprises a slot 144 on the float 104 and a pin 132 on the support beam 118. The pin 132 slides along the slot 144 between a first position 146 corresponding to the in-use configuration and a second position 148 corresponding to the stowed configuration. The first position 146 and second position 148 are at opposite ends of the slot 144. The trajectory of relative movement between the float 104 and float end 128 of the support beam 118 is controlled by the shape of the slot 144.
To improve stability, the float connection 124 also includes a pivot 150. The pivot 150 is provided at the float end 128 of the support beam 118, such that relative movement between the float 104 and support beam 118 is limited to rotational or pivotal movement of the float 104 on the float end 128 of the support beam 118. The pivot 150 is located distally of the pin 132. The slot 144 is arc-shaped corresponding to a trajectory of the pin 132 about a radius of curvature centred at the pivot 150. The pivot 150 therefore is a fixed point at which relative movement is purely rotational whereas, at the pin, relative movement comprises a translation movement.
The pins 132, 140 and respective slots 144, 152 are disposed on opposite sides of the float end 128 of the support beam 118. Therefore, the float connection 124 comprising the pins 132, 140 and slots 144, 152 both controls relative movement between the float 104 and support beam 118 and inhibits undesirable movements between the two.
The float end 128 is located in a channel 154 of the float 104. As shown in
Each end wall 156, 158 defines a position of the float end 128 of the support beam 118 when in a respective one of the stowed configuration and in-use configuration. End wall 156 defines the location of the float end 128 when in the in-use configuration as shown in
The float connection may take other forms. For example, the float connection 200 in
Controlling relative movement ensures the float is consistently positioned in the in-use configuration which, when similarly performed for the opposite float 106, ensures proper balancing of the vessel 100. Similarly, inhibiting undesirable movements reduces the potential for damage resulting from repeated impact loads of swells and water movements during use.
The float connection 124 described above helps to ensure that the float 104 maintains a common orientation in both the in-use configuration and stowed configuration. This means that if the float 104 is vertical in the in-use configuration, it will have the same orientation, and thus be vertical, in the stowed configuration. Moreover, by controlling a height of the support beam 118 as described below, the float connection assembly 108 maintains a common draft of the float 104 when in both the in-use configuration and the stowed configuration.
By maintaining a common draft, the portion of the float 104 that is below the waterline in use is substantially the same as the portion of the float 104 below the waterline when stowed. Anti-fouling paint need only be applied up to the height of the draft of the float 104 in the in-use configuration, yet that is sufficient to substantially inhibit marine growth over the float 104 when in the stowed configuration, since the same portion of the float 104 is submerged in each case.
The actuation system 120 similarly ensures the float 104 is maintained in a consistent orientation in both the in-use and stowed configurations. It does so by controlling relative movement, or rotation, of the float 104 relative to the support beam 118. With reference to
One rope 162 moves the float connection assembly 108 to the in-use configuration and the other rope 164 moves the float connection assembly 108 to the stowed configuration. The rope 162, 164 are operated by applying tension to one rope 162 at a time 164. For example, pulling rope 162 will result in contraction of the float connection assembly 108, and rotation of the float 104 on the support beam 118, to the stowed configuration. Conversely, pulling rope 164 will result in extension of the float connection assembly 108, and rotation of the float 104 on the support beam 118, to the in-use configuration.
Rope 162 passes around or through guide pulleys 166, 170 and can be accessible from the main hull 102. In an embodiment, the rope 162 is connected to the halyard (not shown) on the mast. In other embodiments, the rope 162 is independent of the halyard (e.g. is a dedicated rope or line)—the independent rope 162 may be connected to the mast or at another appropriate position. Rope 164 passes around pulleys 172, 166, 170 to also be accessible from the main hull 102 for operation. In an embodiment, the rope 164 is connected to the reacher winch (not shown). In another embodiment, the rope is independent of the reacher. The operation of the ropes will be understood from
In some embodiments, the ropes or cord lengths are a single length fixed at to the float at a common point—e.g. at point C and passing through eyelets 174, 176 shown in broken lines, but otherwise having the same path as rope 164.
While the present teachings can be used on a vessel having a single float, or a dual-hull vessel, the present vessel 100 comprises two floats 104, 106. The actuation systems of the two corresponding float assemblies 108, 110 may be interconnected—e.g. form a common length of rope—so that operation of the actuation system of one float assembly concurrently actuates the actuation system of the other float assembly. For example, as shown in
In some embodiments, the float 184 may be connected to the main hull 186 by an elbow beam 188. This would allow both the float end of the elbow beam 188 to remain connected to the float and the hull end to remain connected to the hull, during movement between configurations. However, this can produce a point of weakness in the middle of the support beam, and makes the use of trampolines more difficult.
In the embodiment shown in
When in the in-use configuration, an angle section 194 at the hull end 120 is seated on a plate 196 on the main hull 102 as shown in
As shown in
To ensure the trajectory of the support beam 118 is controlled and consistent, the float connection assembly also includes a stabiliser (see
To reduce pivoting of the support beam 118 about the longitudinal axis of the frame 184, the stabiliser also includes an alignment member 188. The alignment member 188 and frame 184 fixed the direction of a length of the support beam 118 and thereby the support beam 118 as a whole, owing to its rigidity. The alignment member 188 and frame 184 thereby maintain a perpendicular alignment between the support beam 118 and longitudinal axis 112—i.e. the support beam 118 moves in a plane for which the axis 112 is a normal—during movement between the stowed configuration and in-use configuration.
When in the in-use configuration, the alignment member 188 is received in a slot 192 in the support beam 118.
To further improve stability, the main support member comprises two spaced support beams 118, 190 as shown in
It will be appreciated that many further modifications and permutations of various aspects of the described embodiments are possible. Accordingly, the described aspects are intended to embrace all such alterations, modifications, and variations that fall within the spirit and scope of the appended claims.
Throughout this specification and the claims which follow, unless the context requires otherwise, the word “comprise”, and variations such as “comprises” and “comprising”, will be understood to imply the inclusion of a stated integer or step or group of integers or steps but not the exclusion of any other integer or step or group of integers or steps.
The reference in this specification to any prior publication (or information derived from it), or to any matter which is known, is not, and should not be taken as an acknowledgment or admission or any form of suggestion that that prior publication (or information derived from it) or known matter forms part of the common general knowledge in the field of endeavour to which this specification relates.
Number | Date | Country | Kind |
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2019902014 | Jun 2019 | AU | national |
Filing Document | Filing Date | Country | Kind |
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PCT/AU2020/050587 | 6/10/2020 | WO | 00 |