GB2530759A

GB2530759A - Sailing boat height and width reduction devices

Info

Publication number: GB2530759A
Application number: GB1417297.7A
Authority: GB
Inventors: Malcolm Shute
Original assignee: Individual
Current assignee: Individual
Priority date: 2014-09-30
Filing date: 2014-09-30
Publication date: 2016-04-06
Also published as: GB2534963B; GB2534963A; GB201417297D0; FR3040365B1; GB201517254D0; FR3040365A1

Abstract

A sailing boat comprises a mast raising, lowering and stowage device comprising a mast lower element 3 and a mast upper element 1 connected together by a disconnectable pivot 2, with each element comprising a sail luff track, a forestay frame 4, 5 attached at one end to one end of a forestay, the forestay being attached at its other end to the upper end of the upper mast element and the forestay frame being attached at its other end to the front of the boat via articulations, a rear support 6 at the stern of the boat for supporting the mast upper element when it is fully lowered, a plurality of shroud elements each comprising a tube or rod 7 having restricted movement so that they remain substantially upright when the mast is lowered and shroud cables 8 attached to the shroud elements and to the mast. The boat may further comprise a walkway 12 on both sides that is retractable by operation of a piston.

Description

SAILING BOAT HEIGHT AND WIDTH REDUCTION DEVICES

Background to the invention

Some sailing boats are used in manners that require a mast to be lowered and sometimes stowed. This can be the case when a boat is on the water and typically concerns bridges over a river or canal which do not provide sufficient air side clearance for a raised mast. Road transportation of a sailing boat invariably requires the mast to be lowered and stowed or removed. Usually, a raisable keel is also used to reduce overall height on the trailer or for navigation in shallow waters.

The raising or lowering of a sailing boat mast can be a complicated manoeuvre. Some boats are equipped for this purpose with a pivot at the base of the mast. Complications arise because of the need to accommodate numerous items attached to the mast including the boom, topping lift, forestay, backstay, and shrouds.

The mast must be supported during the raising or lowering manoeuvre so as to control its trajectory and carry its weight in a safe manner. If the boom is not removed or disconnected from the mast, it must also be supported and it's movement controlled. If movement of either the boom or the mast or both are uncontrolled, the centre of gravity of the mast assembly may move laterally with respect to the centre-line of the boat and cause a rocking movement of the boat thereby de-stabilising the entire boat.

The various cables and ropes such as topping lift, forestay, backstay and shrouds, which are normally tight and hence in predetermined and appropriate positions on the boat when the mast is erect, become loose with a lowered or partially lowered mast and must be managed so as to avoid them becoming entangled in a multitude of ways amongst themselves or with various boat appendages.

Once in the lowered position, the mast's weight must be carried and secured by appropriately positioned supports. If the mast remains attached to the pivot at its base, it typically overhangs the back of the boat (as usually a mast is lowered towards the rear) by a substantial amount and manoeuvring of the boat is rendered more difficult. Additionally the aforementioned cables and ropes may become draped around the boat and descend into the water surrounding the boat. In the latter situation there is a risk of entanglement and most significantly with the boat's propeller or rudder.

Particularly in the case of road transportation of the boat, it may be necessary to disconnect the mast from its base and advance the mast along the length and centre-line of the boat such that any overhang, either at the front or the rear, is minimised.

Road transportation legislation in several countries limits the maximum size of vehicles and trailers. If special requirements such as wide load escort vehicles are to be avoided, widths are typically limited to about 2.44-2.55 metres and trailed length to about 12 metres. These limitations affect the overall geometry of a boat which may be towed without incurring the special transport requirements.

A boat which is designed to be as large as possible whilst respecting these limitations must be relatively slender with a small ratio of beam to overall length. Sailing boats with a cabin usually have a central stairway to access the cabin from the rear deck area and access to the front deck of the boat is achieved by walkway surfaces on either side of the cabin roof On a boat with a beam less than or equal to the 2.44 -2.55 metres maximum width, compromises occur. Either deck walkways are provided for forward access which are typically significantly lower than the central area of the cabin roof and as a consequence reduce the width of cabin with comfortable height, or good cabin height is maintained across a large proportion of the hull width but access to the front deck of the boat imposes the need to climb up onto and along the cabin roof DescriDtion of the invention The invention provides a set of devices to reduce the height and width of a sailing boat to suit transport and navigation constraints. The height aspect is facilitated by raising, lowering and stowage of the mast in a quick and safe manner. The invention includes a solution to avoid the shrouds hanging loosely and inconveniently when the mast is lowered. The width aspect is achieved via over-hanging walkways which may be extended or retracted. The combination of height and width reductions allows the size of the boat to be maximized for normal operation but reduced to comply with road transportation legislation limits and other navigational constraints (eg. bridges).

The description of the invention refers to the following drawings and items: Figure_i mast in lowered position with forestay secondary frame closed Figure_2 mast in lowered position with forestay secondary frame open Figure_3 sections through walkway frames and mechanisms Item 1 mast upper element Item 2 pivot between mast lower and upper elements Item 3 mast lower element Item 4 forestay primary frame Item 5 forestay secondary frame Item 6 rear support for lowered mast Item 7 shroud rod or tube (shroud lower element) Item 8 shroud cable (upper part of each shroud) Item 9 forestay frame rope Item 10 forestay pulley block assembly Item ii deck pulley Item 12 longitudinal walkway frame Item 13 cantilevered transverse walkway tubes Item 14 structural tube attached to or an integral part of the boat structure Item 15 walkway frame pivot Item 16 walkway netting or fabric Item 17 mechanism for extending and retracting the walkway Figures_i to 3 present an embodiment of the invention. Figure_i shows the mast fully lowered and with the mast upper element (1) attached via an articulation (2) to the lower element (3). A partially exploded view of an embodiment of the articulation is included and shows pins (retracted for ease of understanding) used to connect the upper and lower elements. The pins may be threaded to provide a way to lock them in place. Also, they may use conical seats to aid alignment of the various parts.

Figure_2 shows the mast in the lowered position with the forestay secondary frame in the folded condition so as to reduce its height. Both of these figures show the walkways extending out over the side of the hull. Figure_3 shows sections through the walkway frame and mechanisms at locations referred to in Figure_2.

The trailing edges of the mast's upper (i) and lower (3) elements have a sail luff slider track and the boom is attached to the lower element of the mast orto the cabin roof. When mast lowering or raising manoeuvres are undertaken, the main sail is fully lowered and all of its sliders are positioned in that portion of the track which is in the mast lower element, just above the boom attachment point. When the mast is erect, the sail luff slider tracks in the upper and lower mast elements align so as to provide an uninterrupted track for the sliders.

A forestay frame assembly is composed of a primary frame (4) with legs attached to the hull or deck of the boat via articulations, and a secondary frame (5) to which the lowest extremity of the forestay is attached. The secondary frame is connected to the primary frame part way along its length via articulations such that the secondary frame may pivot away from the primary frame. Movement of the frame assembly is controlled by a rope (9) that first passes through a pulley (ii) which is attached to the deck, then rises to pass through a pulley block assembly 00) linking and controlling the distance between the primary and secondary frames.

By progressively releasing the rope (9), the forestay frame assembly rises, pivoting about the articulations at the base of the primary frame legs, resulting in the mast upper element (3) rotating downwards about its pivot. In this way it is lowered and comes to rest upon the rear support (6). Further releasing of the rope enables the secondary frame to pivot away from the primary frame such that the forestay itself can move down through its natural arc and reach a horizontal position sitting on or along-side the already lowered mast upper element.

The lowered mast upper element (3) may be disconnected at the pivot (2) and longitudinally translated forwards by means of a sliding motion facilitated by rollers or sliders located on the top of the mast lower element (1) and on the top of the rear support (6). When the mast upper element has reached its fully forward position it may be secured with locking devices.

With the mast upper element attached at the pivot (2), it may be raised by pulling on the rope (9) which causes the primary and secondary frames to first pull together and the forestay to rise into a triangulated position relative to the mast upper element. Further pulling on the rope causes the mast upper element to rise. When the mast upper element has reached its fully erect position (for normal operation of the sailing boat), the forestay primary and secondary frames are attached to the deck with a locking device. Once the locking device is in place, the tension in the rope (9) may be released.

The lower element of each shroud (7) consists of a stiff rod or tube to a height that is on the same vertical level as the mast pivot (2). At their bases, the rods/tubes (7) are attached to the hull in a way that enables them to continue to stand upright even when the normal tension in the shrouds is reduced or removed when the mast upper element is lowered. In this way, the upper part of each shroud (8), comprised of a cable, is held up so that it does not drape over the side or the deck of the boat.

Figure_3 shows sections through the over-hanging walkway arrangement. The location of each section is identified in Figure_2.

Each walkway (typically with one each side of the boat), comprises a longitudinal frame (12) with a pivot (15) at one end which is structurally attached to the hull or deck of the boat. Transverse elements (13) are attached to the longitudinal frame (12). The transverse elements (13) are engaged in tubes (14) which are structurally attached to, or are an integral part of, the boat structure. A linear displacement mechanism (17) is used to push the transverse element outwards or pull it inwards. Figure_3 shows an embodiment of the invention with a piston moving along a threaded shaft to extend or retract the walkway. As the transverse element (tube) is moved in or out, the longitudinal frame rotates about the pivot (15). The transverse elements (13) are dimensioned, relative to the structural tubes (14), such that motion of the walkway frame about its pivot and consequential angular motion of the elements, is accommodated.

The walkway surface is comprised of a netting or fabric (16) which is stretched between the walkway structural frame (12) and the boat hull or superstructure. When the walkway is retracted, the walkway netting (16) slackens and descends. An electric or a hydraulic actuator may be used to provide the motive force to extend or retract the walkway. A locking device may be provided to secure the walkways in either the fully extended position or the fully retracted position.

The structural frames of the walkways, when extended, over-hang the sides of the hull, and may be equipped and used as fenders to protect the boat's hull against minor impacts and rubbing against mooring jetties or other boats. Additionally, the mechanism (17) may include a spring and/or damper to enable it to resist and/or absorb shock loads imposed upon the walkway structure.

Claims

Claims 1. A sailing boat mast raising, lowering and stowage device comprising: a mast lower element with a sail luff track holding the lowered sail's sliders; a mast upper element with a sail luff track which precisely aligns without interruption with the track of the mast lower element and with the upper extremity of the forestay attached near to or at the upper end of the mast upper element; a disconnectable pivot, whose axis is perpendicular to the vertical centre line plane of the boat, connecting the mast lower and upper elements; a forestay frame, at the front of the boat, attached to the hull or deck via articulations at one end and to the lower end of the forestay at the other end; a rear support at the stern of the boat to support the mast upper element when it is fully lowered; multiple shroud lower elements each comprising a tube or rod whose movement is restricted such that it remains close to upright when the mast is lowered; shroud cables attached to the shroud lower elements at one end and to the mast at the other end; wherein raising of the said forestay frame about its articulations causes the said mast upper element to lower by rotation about the said pivot until the mast upper element comes to rest upon the said rear support with the said shroud lower elements holding the said shroud cables up (so as to not drape over the boat), and the reverse movement, lowering the said forestay frame, causes the said mast upper element to rise until it reaches its fully upright position.
2. The invention of claim 1, whose said forestay frame comprises: a primary frame attached to the hull or deck via articulations at its lower end; a secondary frame attached to the lower end of the forestay at its forward extremity and to the upper end of the primary frame via articulation(s) at its other extremity; a pulley block attached to the primary frame; a pulley block attached to the secondary frame; a pulley attached to the deck; a (forestay frame) rope or cable passing through the said deck pulley, then through the said primary frame pulley block, then through the said secondary frame pulley block, and with one or more loops between the pulley blocks, has its end attached to a point on the said primary frame; wherein by pulling on the said rope, the said primary and secondary frames are pulled together by the rope tension and which also pulls on the forestay which in turn pulls on the said mast upper element thereby raising it, and in reverse, when tension in the said rope is reduced and finally released, the said mast upper element lowers until it comes to rest on the said rear support and the said primary and secondary frames are free to move apart causing them to both lower in effective height.
3. A sailing boat mast raising and lowering arrangement as in claims 1 and 2 with the said dis-connectable mast pivot, additionally comprises: a roller (or low friction slider) on the top of the said mast lower element; a roller (or low friction slider) on the top of the said rear support; wherein the mast upper element, once lowered onto the rear support, can be detached from the mast lower element via the disconnectable pivot and rolled or slid forwards over the rollers or sliders into a forward position overthe boat minimising the overall mast overhang with respect to the hull.
4. A sailing boat mast raising and lowering arrangement as in claim I with shroud lower elements which are connected to the boat structure via pivoted joints which restrict movement in all directions except pivoting towards the front of the boat to facilitate forward translation of the mast upper element into a storage position
5. The invention of claims 1 and 2 additionally comprises a power-assisted drive to control the tension within and the movement of the said rope.
6. The invention of claim 1, additionally comprises: two longitudinal frames on either side of the boat, each attached to the boat at an extremity via a pivot; multiple structural tubes attached to or forming an integral part of the boat structure; transverse tubes, rigidly attached to the said longitudinal frames, freely sleeved within the said structural tubes; two pistons each located within one of the said structural tubes on either side of the boat; two walkway surfaces made of netting or fabric connected and stretched between the said longitudinal frame and the boat hull or superstructure, one on either side of the boat; wherein movement outwards of the said piston (or its extension in length) moves its associated transverse tube outwards causing the said longitudinal frame to pivot outwards causing the extension and tensioning of the said walkway surface, and the reverse movement causes the said walkway surface (netting or fabric) and its associated longitudinal frame to retract and the walkway surface to collapse.
7. The invention of claims I and 6, additionally comprises: one or more springs and/or dampers within the said piston whereby the said longitudinal frame can move to absorb shock loads imposed upon it due to mooring or other impacts.
8. The invention of claims I and 6, additionally comprises an electric or hydraulic actuator in the place of the said piston to extend or retract the said walkway.