GB2389093A

GB2389093A - Twin mast sail rig

Info

Publication number: GB2389093A
Application number: GB0212685A
Authority: GB
Inventors: Richard Glanville
Original assignee: Individual
Current assignee: Individual
Priority date: 2002-05-31
Filing date: 2002-05-31
Publication date: 2003-12-03
Also published as: WO2003101822A1; GB0212685D0; AU2003273563A1

Abstract

A sail rig 2 for a multihull sailing vessel 1 or a vessel with a wide beam comprises two masts 3 and 4, one mounted on the port side 1p and one mounted on the starboard side 1s of the vessel. The rig includes two forestays 5 and 6, each attached to the top of a mast and crossing to terminate at the bow of the hull on the opposite side of the vessel and two backstays 7 and 8, each attached to the top of a mast and crossing to terminate near the stem of the hull on the opposite side of the vessel. A compression strut 9 links the tops of the masts, while each of the masts is rotatable about its vertical axis and is provided with a boom 10 and 11 and a sail 12 and 13.

Description

Twin mast sail rig.

This invention relates to a sail rig for a wmdpowered vessel, such as a yacht or vessel which 'ares sail power for auxiliary propulsion. This sail rig is particularly suitable for rnulti},ull yachts with a wide beam Conventional multihull rigs step a single most on the crossbeam or bridgedeck, on the vessel centreline. Their shroud base is half the vessels beam and therefore mast compression is high. The crossbeam or oridgedeck has to be designed to withstand large, rig induced bending moments. The shrouds limit rig rotation, and particularly when wing masts are used, it can be impossible to de-power the. ig in stow conditions Reefing the mainsail is also difficult if the apparent wind direction is aft of the beam.

An object of this invention is to provide a rig that eliminates the rig induced bending moment in the vessels crossbeam or bridge deck, the compress on loads on the masts are low because the effective shroud base is the full beam of the vessel, and the rig is free to rotate and able to feather whatever the apparent wind angle According to the present invention a sail rig for a multibull sailing vessel or a sailing vessel with a wide beam or such a vessel provided with auxilia.y sail propulsion, comprising two masts of aerodynamic configuration in transverse section, one mounted on the port side and one mounted on the starboard side of the vessel, each of the said masts is able to rotate about its vertical axis, two forestays, one attached to the top of each of the said masts and crossing to ter.nnate at the bow of the hull or outrigger on the opposite side of the vessel, two backstays, one attached to the top of

each of the said masts and crossing to terminate near the stern of the hull or outrigger on the opposite side of the vessel, a compression strut that links the tops of the said masts, two booms, one operating with each of the said masts, two sails7 one located between each of the said masts and said booms.

An embodiment of the invention will now be descnbed, by Ray of example, with reference to the accompanying drawings, in which: -

Fire I is a perspective view of a sailing catamaran provided with a sail rig according to the present invention, Figure 2 Is a front elevation of the said catamaran and sail rig; and Figure 3 is a plan view of the said catamaran and sail rig; and Figure 4 is side elevation of said catamaran and sail rig.

The sailmg catamaran I shown in figures I, 2, 3 and 4, Is provided with a sail rig 2 which consists of a starboard mast 3 mounted on the starboard side of the catamaran, a port mast 4 mounted on the port side of the catamaran, a starboard mast forestay 5 extending between the top of the starboard mast 3 and the bow of the port hull of the catamaran 1 P. a port mast forestay 6 extending between the top of the port mast 4 and the bow of the starboard hull of the catamaran I S. a starboard mast backstay 7 extending between the top of the starboard mast 3 and the transom of the port hull of the catamaran IP, a port mast backstay 8 extending between the top of the port Tnast 4 and the transom of the starboard hull of the catamaran 1 S. said forestays 5 and 6, and backstays 7 and 8 can be of fixed length or their length may be adjusted in

( order to cant the rig or change the rake, a compression strut 9 connecting the top of the starboard mast 3 to the top of the port mast 4, a starboard boom 10 pivoting about the lower end of the starboard mast 3, a port boom I I pivoting about the lower end ofthe port mast 4, a starboard sail 12 that is attached to the trailing edge of the starboard mast 3 and to the starboard boom 10, a port sail 13 that is attached to the trailing edge of the port mast 4 and to the port boom I I, said sails 12 and 13 may be stiffened by battens 1 2B and i 3B, said battens may be horizontal or vertical.

The starboard mast 3, boom 10 and sail 12 may rotate about the vertical axis 3V of the mast 3, or said mast can be fixed and the boom 10 and sail 12 may rotate about the fixed mast 3. The port mast 4, boom I 1 and sail 13 may rotate about the vertical axis 4V of the mast 4. or said mast can be fixed and the boom 10 and sail 1 I may rotate about the fixed mast 4.

The crossed forestays 5 and 6, and the crossed backstays 7 and 8, working in combination with the compression strut 9, give both lateral and longitudinal support to the rig. Shrouds are not needed for lateral support and without them the rig is free to rotate, and can be feathered quickly whatever the apparent wind angle.

The sails 12 and 13 can also be reefed without altering the vessel's heading The compression load In the masts 3 and 4 is low because the effective shroud base is equal to the lull beam of the vessel. The vessels crossbeam or bridgedeck is not subjected to rig induced bending moments as the masts 3 and 4 are stepped directly onto the port and starboard hulls or outriggers I P and I S

Claims

( CLAIMS

I. A sail rig for a multibull sailing vessel or a sailing vessel with a wide beam or such a vessel provided with auxiliary sail propulsion, comprising two masts of aerodynamic configuration in transverse section, one mounted on the port side and one mounted on the starboard side of the vessel, each of the said masts is able to rotate about it's vertical axis, two forestays, one attached to the top of each of the said masts and crossing, to terminate at the bow of the hull or outrigger on the opposite side of the vessel, two backstays, one attached to the top of each of the said masts and crossing to terminate near the stern of the hull or outngger.on the opposite side of the vessels a compression strut that links the tops ot' the said masts, two booms, one operating with each of the said masts, two sails, one located between each of the said masts and said booms.

A sail rig as claimed In Claim I, where the transverse section of the masts is not of

aerodynamic configuration.

3. A sail rig as claimed In Claim I or Claim 2, where the two forestays, the two backstays and the compression strut are not attached to the top of the masts, but are attached to points lower down the masts.

s 4. A sail rig as claimed in Claim 1, Claim 2 or Claim 3, where the rig can be canted in the transverse plane and in the longitudinal plain by adjusting the lengths of the forestays and backstays 5. A sail rig as claimed in Claim 2, Claim 3 or Claim 4, where the masts are not able to rotate about their vertical axis.

6. sail rig as ciamed in any one of (:laims 1 to 5, where the two booms are Wishbone booms, or Balestron booms, or where the booms are not mounted on the masts but pivot about fittings attached to the hulls or outriggers independent of the masts. 7. A sail rig as claimed in any one of Claims 1 to 6, where the length of the compression strut can be adjusted.

8. A sail rig as claimed in any one of Claims 1 to 7, where headsets or spinnakers are flown ahead of the masts 9. A sail rig for a sailing vessel or a vessel provided with auxiliary sail propulsion, substantially as hereinbefore described with reference to and as illustrated in the accompanying drawings.