PROJECT WINDRIGGER - July 2001 installment

Project Summary

I have reached the conclusion that its time obtain a usefull outcome to the project. So, considering the following project objective written about 8 years ago - I require a safe and comfortable boat which was easy to rig and sail; simple to launch and reload for trailering behind a family-size car; affordable (costing less than $10000 to build) and fast as my Flying Dutchman - The present version of Windriggercat fulfils this objective. Since its first launching in January 1995, I have sailed it regularly , trialling various modifications whilst taking my family and friends sailing. The following are highlights of its development which support this conclusion:

Photo 1. - sailing on an inland lake at Canberra March 1995 - with twin spade-rudders and minikeels as shown at the bottom of webpage 3. There were times on this lake when the cat appeared to sail as fast as the Dutchman.

When we moved to Nelligen in 1996, living 24km upstream from the Pacific Ocean on the Clyde river, I had a my first experience of sailing the cat in 3-5 knot tidal currents and low wind-strength. On this memorable occasion , the wind dropped and I had to accept a tow to the shore, by a motor boat. Then the current drove the cat into some moored oyster-punts and the its minikeels and spade-rudders became entangled with their mooring lines. This is typical of other bad experiences and problems which I encountered during the last 5 years, whilst sailing the cat on inland waters. So development of the cat has mainly involved finding and implimenting solutions to these problems - more product development than yacht research.

After the mooring-lines encounter, I removed the minikeels and replaced them with chine-winglets as shown in Photo 5 and described below. These provide adequate windward performance.

Photo 2- crew: my wife Ineke and Nessie our terrier. Note the aft bridgedeck extension supporting a single lift-up rudder and the outboard motor mounted on the fore-bridgedeck. Ultimately, I shifted the outboard mounting aft for quick access by the helmsman.

As much as I dislike outboard motors I have to admit that a motor is essential when sailing on inland waters and, it makes people more inclined to sail on the cat. These modifications eliminated the mooring- line problem and improved control of the cat in the tidal current.

Photo 3 shows the cat on a mooring close to home. I moored it fully-rigged for three periods of two weeks each. The only reason for leaving the sails up was to save me the time and effort to rig them. I would prefer sails that furl by rolling around the mast - sailboard sails without battens would be ideal.

Whilst on the mooring the cat survived some very stormy conditions which demonstrated a big feature of this sailrig - if the winds become dangerously violent, simply unhook the mainsheets so the sails feather the wind - and the danger is eliminated.

The hulls have survived rough handling - I have hit oyster racks, rock outcrops on the river banks, submerged trees and rocks, without sustaining structural damage. The cat has been stored exposed to the weather and with water in the hulls - there is no sign of rot. Excellent considering one hull is 8 and the other 6 years old. The hulls were constructed from marine ply and wood available from the local builders-supply shops. Building was strictly in accordance with the West System - no metal fastenings and epoxy coating of all wood.

The sailrig - easy to rig as shown in Photo 4. Easy to sail - when running before the wind the sails can be set on opposite sides of the cat (bat-wing) to provide a balanced sailrig. Safe - gybing does not injure or threaten people onboard the way a conventional mainsail boom does. This is an essential as accidental gybes happen more often when sailing on inland waters. To pass under a low bridge each sailrig is lifted out of the hull and layed on the deck.

Safe from capsizing - never had to worry about capsizing, never had a hull lift out of the water or required passengers to sit on the windward hull.

Launching the cat from its trailer and unfolding the hulls to the sailing beam configuration, is no problem for two people - as shown at the bottom of webpage 3.

During the 5 years I have been sailing the cat on 24km of the Clyde river, I have seen no more than 10 sailing boats - mostly deep-keelers under power. I have found it a wonderful place to sail and much safer than sailing offshore. Maybe others are interested in building and sailing this cat - the only way find this out is to produce construction drawings and offer them for sale.

The chine-winglets are based on a publication titled Winglets and Vortex Generators - page 35 Multihulls Magazine Nov/Dec 1990. The winglets shown in Photo 5 made it almost impossible to turn the cat when under motor power. By a trial and modify process, I settled for chine-winglets comprising 4 lengths of aluminium angle of 25x25mm. cross-section by 850mm.long each fastened to the bottom chines of the hulls and 450mm.from each bow.

During April this year I replaced the chine-winglets with a centreboard mounted on the bridgedeck - as shown in Photo 6. I designed it so that the angle of attack of the board could be varied up to 10 degrees and automatically adopt a positive angle of attack when the cat tacked. I trialled it last April and it appears to work as planned. I used twin spade-rudders for this trial.

I intend to use this arrangement on a catamaran currently under construction, based on two 6.8m fibreglass hulls. The centreboard used for the trial is shown in the photo resting against the starboard bow, a much larger board is in the centrecase. This centrecase structure is not good to look at - I intent to redesign the bridgedeck incorporating the centrecase into a dory-shape hull about 3 to 4 metres long,.mounted on the bridgedeck centreline. Note the outboard mounted aft - it is a 3.3hp Mercury with a clutch, forward gear-control and reverse by rotating it 180 degrees.

Next month I shall provide an update of the Windrigger MK II proa development, construction of a second fibreglass hull and bridgedeck for a catamaran using the 6.8m fibreglass hulls.

For further information - please e-mail me on smithvanaalst@bigpond.com