Sail rig and staysail system

Abstract: A sail rig for a sailing vessel or a vessel provided with auxiliary sail propulsion comprises a mast 12, a continuous yard/boom 13 provided on the mast 12, a backstay 14, a main sail 15 located between the mast 12 and the backstay 14, a forestay 17 and a foresail 16 mounted on the forestay 17, the mast 12 and the yard/boom 13 being rotatable or the yard/boom 13 being rotatable relative to the mast 12, and the foresail 16 consists of a plurality of ribs 18 spaced apart along the stay 17 and through which the stay 17 extends and an outer covering of flexbile material 19 placed in contact with and secured to the ribs 18.

Description: This invention relates to a sail rig for a sailing vessel, such as a yacht, or a vessel provided with auxiliary sail propulsion. GB-A-2 033 308 discloses a sail rig for a sailing vessel or a vessel provided with auxiliary sail propulsion. The sail rig comprises a mast unstayed to the hull of the vessel, a continuous yard/boom mounted on the mast and rotatable relative thereto, the yard/boom and a foresail or staysall being mounted on the mast, and a main sail located between the mast and the yard/boom. The present invention makes use of a similar sail rig and is characterlsed in that a backstay extends between the upper end of the mast and the aft end of the yard/boom, a forestay extends between the mast and the forward end of the yard/boom, said backstay and said forestay being pretensioned, tension in the forestay being transmitted to the backstay, the pretensioned forestay being positioned rearwardly of the leading edge of the foresail. The advantages of the present invention include the fact that the unstayed mast reacts with the sail surfaces and stays as a free cantilever structure which may deflect sideways under wind pressure. The fore and aft stays which are pretensioned through the yard/boom, give forward and aft rigidity to the mast and the tensions are transmitted through the rigid yard/boom. The sail rig is similar to that of a crossbow and provides a strong resilient structure. The pretensioning of the forestay and backstay maintain efficient sail shape when the mast is deflected sideways. The forestay, mast, yard/boom and backstays elements form an integral unitary structure which can be fitted to a hull as a unit. An embodiment of the present invention will now be described, by way of example, with reference to the accompanying drawings, in which:- Figure 1 is a side elevation of a sailing yacht provided with a sail rig according to the present invention; Figure 2 is a diagrammatic perspective view of a stay sail according to the present invention; and Figure 3 is a plan view of a modified form of rib showing how the camber along the sail can change. The sailing yacht 10 shown in Figure 1 comprises a hull and a sail rig 11 which consists of a mast 12 unstayed to the hull. The mast may or may not be of the cantilever type. The sail rig 11 further consists of a continuous yard/boom 13 mounted at the lower end of the mast 12, a backstay 14 which extends between the upper end of the mast 12 and one end of the yard/boom 13, a main sail 15 which is slidable along the mast 12 and is located between the mast 12 and the backstay 14, and a staysail 16 which is set on a forestay 17 which extends between the mast 12 and the other end of the yard/boom 13. The main sail 15 may be stiffened by battens 15a. The backstay 14 and forestay 17 are both pretensioned. The tension in the backstay 14 is reacted by the forestay 17. The forestay 17 may or may not be located at the extreme fore end of the staysail 16. The forces generated by the staysail 16 balance those produced by the main sail 15 and thus the force required to sheet the rig to the desired angle for optimum sailing is reduced. The entire mast 12 and yard/boom 13 may rotate together about the axis of the mast 12 or the mast 12 can be fixed and the yard/boom 13 may rotate about the fixed mast 12. When sailing the leech tension in the main sail 15 replaces some or all of the tension in the backstay 14 thus maintaining tension in the forestay 17. Preloading tension in the mast 12 with the backstay 14 is necessary with a cantilever type mast 12 in order to allow for mast deflection when sailing. The staysail 16 is shown more clearly in Figure 2 and is generally of an aerodynamic configuration in transverse section. Under wind load the camber of the sail 16 may change along its length. The staysail 16 comprises a plurality of spaced apart ribs 18 which in plan view have a rounded front end and taper in width to a trailing edge, said ribs 18 being slidably mounted on the forestay 17, and a sail cloth or other flexible material 19 spans the gaps between the ribs 18. The material 19 may be in one piece and extend over each side of the ribs 18 or it may be discontinuous at the ribs 18. The material 19 is fixed to the ribs 18 in any suitable manner. The staysail 16 is erected by a halyard (not shown) and can be reefed in order to reduce its effective sail area. The use of ribs 18 and the choice of position of the forestay 17 minimises the tensions required to operate and reef the sail 16 efficiently. The ribs 18 may be formed of wood, or metal, or plastics material which may be fibre reinforced. The lowest rib 18 and boom 13 may be integral. Figure 3 shows a plan view of a modified form of rib 18 which has a flexible trailing end portion 18a which allows the camber of the sail to change along its length.

Claims: A sail rig (11) for a sailing vessel (10) or a vessel provided with auxiliary sail propulsion, comprising a mast (12) unstayed to the hull of the vessel, a continuous yard/boom (13) mounted on the mast (12), a main sail (15) located between the mast (12) and the yard/boom (13), and a foresail or staysail (16) mounted on the mast (12) and the yard/boom (13), said yard/boom being rotatable relative to the mast (12), characterised in that a backstay (14) extends between the upper end of the mast and the aft end of the yard/boom (13), a forestay (17) extends between the mast (12) and the forward end of the yard/boom (13), said backstay (14) and said forestay (17) being pretensioned, tension in the forestay (17) being transmitted to the backstay (14), the pretensioned forestay (17) being positioned rearwardly of the leading edge of the foresail (16). A sail rig as claimed in Claim 1, in which the foresail (16) comprises a plurality of ribs (18) spaced apart along the pretensioned forestay (17) and through which the forestay extends, and an outer covering (19) of flexible material placed in contact with and secured to the ribs. A sail rig as claimed in Claim 1 or Claim 2, in which the foresail (16) is of aerodynamic configuration in transverse section. A sail rig as claimed in Claim 2, in which the ribs (18) have a flexible trailing end portion to allow the camber of the foresail (16) to change along its length. A sail rig as claimed in Claim 2, in which the ribs (18) in plan view have a rounded leading end and taper in width to a trailing edge. A sail rig as claimed in any one of Claims 2 to 5, in which the ribs (18) are formed of wood, or metal, or plastics material.

Inventors: HOWLETT IAN CHARLES, HOWLETT, IAN CHARLES
Applicants: HOWLETT IAN C, HOWLETT, IAN CHARLES
Application year: 1990
Main classification: B63H9
IPC codes: B63H9