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<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 3.2//EN"> <HTML> <HEAD> <META NAME="GENERATOR" Content="Symantec Visual Page 1.0.1"> <META HTTP-EQUIV="Content-Type" CONTENT="text/html;CHARSET=iso-8859-1"> <TITLE>AYRS #101 (a)</TITLE> </HEAD> <BODY TEXT="#000000" BGCOLOR="#FFFFFF" LINK="#0000FF" VLINK="#551A8B" ALINK="#0000FF"> <P><A HREF="../../speedsl/index.html">Back to "Speedsailing."</A></P> <P ALIGN="RIGHT">ISSN 0144 - 1396</P> <H1 ALIGN="RIGHT">AYRS 101</H1> <P ALIGN="RIGHT">AUGUST 1985</P> <H2>Windmills and Hydrofoils</H2> <CENTER> <P><IMG SRC="p1.jpg" WIDTH="308" HEIGHT="399" ALIGN="BOTTOM" BORDER="0"><BR> The Kielder Daysailer with Tethered Kite Rig. T.S. Morley</P> </CENTER> <CENTER> <H3><A NAME="contents"></A>CONTENTS</H3> </CENTER> <CENTER> <P> <TABLE BORDER="0" CELLPADDING="0" CELLSPACING="0" WIDTH="75%"> <TR> <TD><A HREF="#tethered">2. Tethered kite rig.</A></TD> <TD><A HREF="101b.html#sampanette">11. Sampanette</A></TD> </TR> <TR> <TD><A HREF="#chairman">4. CHAIRMAN'S REPORT</A></TD> <TD><A HREF="101b.html#bandersnatch">12. BANDERSNATCH</A></TD> </TR> <TR> <TD><A HREF="#news">5. News</A></TD> <TD><A HREF="101b.html#foils & weight">17. Foils & weight</A></TD> </TR> <TR> <TD><A HREF="#sabu">6. SABU</A></TD> <TD><A HREF="101c.html">19. Foil movement in waves</A></TD> </TR> <TR> <TD><A HREF="#Bruce foiler">7. A Bruce foiler</A></TD> <TD><A HREF="101c.html#Wind turbine">24. Wind turbine/propeller</A></TD> </TR> <TR> <TD><A HREF="101b.html#blot">9. The Blot</A></TD> <TD><A HREF="101c.html#vertical axis mill">27. Vertical axis windmill</A></TD> </TR> </TABLE> </P> </CENTER> <P>(page 1)</P> <P> <HR> </P> <H3><A NAME="tethered"></A>Tethered Kite Rig</H3> <P>The Kielder Daysailor moving nicely at about an S.L.R. of 1.0 under her Tethered Kite rig (cover photo) (Pat appl No. 8203621). After several test sails in winds of up to force four and mainly single handed, I have reached the following conclusions:</P> <OL> <LI>As expected it is an excellent sail for broad reaching and running; tacking downwind, or wearing being easily effected by simply adjusting its pair of braces. <LI>As a bonus, reaching up to four points off the apparent wind (6 points true) is possible but the boat must be worn to change tacks, so windward performance is poor. A higher aspect ration kite of lower camber and rhombus-shaped (to lower centre of effort) could be designed for close reaching. Its downwind performance would suffer and the one shown in the photograph is a good compromise. <LI>Raising and lowering the sail can be done easily singlehanded with the boat running. The spar, which supports the sail's shoulders, folds as the sail is lowered and may be stowed in the cuddy or semi-folded along the forward gunwales. <LI>The area may look small but it is about all she and I can handle when reaching in a force four. It is approximately twice the boat's waterplane area. If the sail was to be used entirely for downwind sailing, its size could be increased by 50%. </OL> <P>THE SQUARE RIG IS BACK.</P> <DIV ALIGN="RIGHT"> <P><I>T.S. Morley 8/84</I></P> </DIV> <P>(page 2)</P> <P><A HREF="#contents">return to Contents</A></P> <P> <HR> </P> <CENTER> <P><A NAME="logo"></A><IMG SRC="AYRS.gif" WIDTH="536" HEIGHT="156" ALIGN="BOTTOM" ALT="AYRS Logo" BORDER="0"></P> </CENTER> <CENTER> <H2>THE AMATEUR YACHT RESEARCH SOCIETY</H2> </CENTER> <CENTER> <P>(Founded June 1955 to encourage Amateur and Individual Yacht Research)</P> </CENTER> <CENTER> <P><B><I>President:<BR> </I>HIS ROYAL HIGHNESS<BR> THE PRINCE PHILIP, DUKE OF EDINBURGH, KG, PC, KT, GBE, FRS</B></P> </CENTER> <CENTER> <P><B><I>Vice Presidents:<BR> </I>Austin Farrar, FRINA<BR> Beecher Moore</B></P> </CENTER> <CENTER> <P><B><I>Founder and Consultant Editor:</I> Dr. John Morwood</B></P> </CENTER> <CENTER> <P>Chairman: Sir Reginald Bennet VRD<BR> Vice Chairman: Mr. C.M.G. Butterfield<BR> Hon. Secretary: Fred C. Ball<BR> Hon Treasurer: Graeme W. Ward</P> </CENTER> <CENTER> <P>Committee<BR> Norman Champ, David Chinery, Mr. & Mrs. S.A Coleman Malden, Tom Herbert, Andre<BR> Kanssen, Tony Milburn, Mrs. Pat Morwood, Theodore Schmidt.</P> </CENTER> <CENTER> <P>Auditor - Robin G. Fautley</P> </CENTER> <P>The Society (open membership) furthers the theory and practice of nautical science and related subjects. We are registered as an educational charity (no 234081) and a company (no 785326) without share capital, limited by guarantee. (VAT no 200 1168 38).</P> <P>The society has members in all countries of the world where sailing is a sport. Information for publication comes from members and people interested in sailing or building yachts. Funds come from members' subscriptions, from the sale of books and from donations. The subscription for the present year is £12.50 or $20.00 USA. New ideas or details of problems are welcome. We try to pass these on to avoid duplication of research and to put people with similar interests in touch with each other.</P> <CENTER> <P><B>Administration and Membership:<BR> Michael Ellison, 10 Boringdon Terrace,<BR> Turnchapel, Plymouth, PL9 9QT, England.</B></P> </CENTER> <P><I>All AYRS publications are copyright. Extracts may only be used by permission of the Editor and Contributor, which will not ordinarily be refused as long as proper acknowledgment is made.</I></P> <P>(page 3)</P> <P><A HREF="#contents">return to Contents</A></P> <P> <HR> </P> <CENTER> <H3><A NAME="chairman"></A>CHAIRMAN'S REPORT</H3> </CENTER> <P>On completing 30 years of existence we may well congratulate ourselves. For although our mission in life is most important and of absorbing interest it is by definition not commercial - and survival unfortunately depends on money. I dare say that not many, even of our well-wishers, expected us to last so long. And even they could not have foreseen the devastating blows, general or particular, that have knocked us about. Recession and runaway inflation on the one hand; the American fiasco on the other.</P> <P>So we may congratulate ourselves on our survival. And we have much to be proud of in the course of these long years. We have justified our existence; wherever we look we see the triumphant applications of ideas diffidently put forward by our modest amateurs. Not least, for instance, certain details in the America's Cup victory; and then there is the huge and growing international programme of speed-sailing that really exhausts the vocabulary of superlatives in scale and speeds - all deriving from our little Portland events of a dozen years or more ago.</P> <P>Publication is once again practicable, though still vastly expensive even on a much more modest scale than of yore. And today we have run into a much more copious commercial competition against our technical works, which once stood almost alone in the field. But we still go on producing new thoughts and practices, and publishing them.</P> <P>So we continue to hold our heads high, bloody perhaps but unbowed. But we do however face a very difficult financial position, as the Treasurer's report shows. Spiraling costs - the old cry - and loss of membership, especially in America, have brought us to a degree of imbalance that is unacceptable. Increasing the subscription is of limited efficacy, and we must once more cut down on our costs, modest as they are, while increasing our publications, our sales and our membership all we can.</P> <P>This is our position. We have a marvelous and quite unique Society, and we are going to have to work pretty hard to preserve it. Your help and suggestions will be welcomed.</P> <P>REGINALD BENNETT</P> <P>(page 4)</P> <P><A HREF="#contents">return to Contents</A></P> <P> <HR> </P> <P><A NAME="news"></A>Portland</P> <P>Portland Speed Week 1985</P> <P>This year the event will involve two weeks from 28th September to 13th October. The first week is for board sailors from U.K. to have their speeds measured so that they can get onto the "ladder" of recorded speeds and if good enough qualify to enter the second week. Entries will again be limited and applications should be sent to the R.Y.A. at Victoria Way, Woking, Surrey, England as soon as possible. In past years there have been few problems for people entering boats and experimental craft but there seems to be an increased interest for this year. Jacob's Ladder has been seen trying new kites for an entry in the "open" class. The event is again being sponsored by Johnnie Walker.</P> <P>Southampton Boat Show</P> <P>13th to 21st September. The 13th is "preview day" with an entry cost of £6.00, open from 0900 to 1700. For the rest it is open from 1000 to 1900 at a cost of £2.50. We have again booked space in the dinghy arena.</P> <P>London Boat Show 1986<BR> Next London Show opens from 1st to 12th January and we will have a stand as usual. The dates are early with trade day on 31st December. <U>We like to have at least two members on the stand throughout the show and would welcome help if you can spare any time.</U></P> <P>New World Record</P> <P>The World Sailing Speed Record Committee met in London on 11th July and ratified the speed of 32.35 knots by Michael Pucher on a sailboard with 4.2 sq.m. sail area on 15th April at Port St.. Louis du Rhone in Southern France. The record was set during a speed sailing event held from 9th to 16th April mainly for sailboards. The "Mistral" wind was gusting to force 10 across low land and a sand beach. Eight competitors exceeded the previous world record, the runner-up at 32.17 knots. The timed runs were also recorded on video. Mr. Pucher is Austrian. Speed meetings have also been held in Australia in December and at Brest, France from 23rd to 29th March to replace their autumn event.</P> <DIV ALIGN="RIGHT"> <P>Michael Ellison</P> </DIV> <P><FONT SIZE="5">NAUTICAL MILE RECORD. How should it be recorded?</FONT></P> <P>(page 5)</P> <P><A HREF="#contents">return to Contents</A></P> <P> <HR> </P> <P><A NAME="sabu"></A>Flying Gaff Rig on Sabu</P> <P>The new rig has so far suffered from lack of sea time. We retired from the 'Round the Island' (force 5 W'ly) when the end of the boom broke and our passage to Plymouth was mainly to windward. The rig is close winded and steady progress is possible tacking through 80 degrees. With the wide beam the yang holds the peak well removing twist from the sail.</P> <P>The main problems are the shrouds wlich lead from the masthead back to the aft edge of the 'wing'. (Cover of pub 95). When the wind is free the leech fouls the shroud and sail shape suffers, c'hafe will be serious on a long passage. The second problem is that the mast can only be supported at the head due to the gaff slider. This means that it tends to bend in the middle especially in a chop with full sail. When the sail is reefed the gaff thrust to the milddle of the mast has to be taken on a line from the throat and this must be treated like a running backstay. Wc have now considerably incrc.~ied the sail area on a mast 6' shorter thar~ the original. She is not slow but no comparison of performance has been possible so far we have yet to "get our act together".</P> <DIV ALIGN="RIGHT"> <P>Michael Ellison</P> </DIV> <P>Prestel ! Micronet ! Viewdata !</P> <P>Are there any members with these facilities or their equivalent Isn't it time the A.Y.R.S. got into the electronic age of communication; electronic mail and notice boards using home computers as Viewdata terminals.</P> <P>I think it is time that the vast store of information and research that has been accumulated over the years by the A.Y.R.S should be computerized to make indexing and cross-referencing more comprehensive.</P> <P>There will be problems of compatibility and useability at first, but I would like to kick off the discussion. It will need someone with much more knowledge than I to get it set up. Recently Mike Ellison has been punching out copy on a very old typewriter. I think a good daisywheel typewriter/printer with word processor is needed, preferably about three similar/compatible computers, i.e. one in the U.S.A., two in the U.K. for starters.</P> <P>As most members are aware, information can be sent from one computer to another using phone lines, and that information can be reformatted by the receiving computer and dumped to the printer - so much less time-consuming than retyping. so, more publications.</P> <P>I would be interested in members' ideas and comments on how to raise the cash to equip with some Information technology equipment.</P> <P>Thanks to Kathy Sharp who retyped <BR> most of this issue on a daisy wheel.</P> <DIV ALIGN="RIGHT"> <P>Norman Champ <BR> Apprentice Editor</P> </DIV> <P>(page 6)</P> <P><A HREF="#contents">return to Contents</A></P> <P> <HR> </P> <DIV ALIGN="RIGHT"> <P><A NAME="Bruce foiler"></A>6501 Budenheim <BR> Südstrasse 25 <BR> 28th December</P> </DIV> <P>The Administrator AYRS<BR> Michael Ellison</P> <P>Dear Sir</P> <P>When I became a member of the AYRS is September 82 you told me that you would bill me a year later. As this has not happened, I must have misunderstood something or you have forgotten me. Now I send you the money for another year.</P> <P>I have also a question and some ideas. Has there ever been an oceangoing Bruce Foiler ? In publication No 93 on page 29 Noel Fuller mentioned that he considered building a 9m Bruce Foiler. Now some thoughts on Bruce Foiler design:</P> <P>Edmund Bruce suggested building a tandem Bruce Foiler because there would be less possibility of both foils coming unstuck when they are to weather. Let's say we use asymmetric foils, which produce zero lift at an angle of attack of minus two degrees. The two foils are mounted on an ama, perhaps similar to Splinter's (see MI October 81), with their chords parallel to the boat's centreline.</P> <CENTER> <P><IMG SRC="p7.gif" WIDTH="308" HEIGHT="196" ALIGN="BOTTOM" ALT="Bruce Foiler drawing" BORDER="0"></P> </CENTER> <P>When the foils are to weather, the aft one produces more lift than the forward one. The centre of resistance moves back and the stern is pushed down. The reverse happens when the foils are to lee. When carefully designed this foil arrangement should keep the boat level and compensate for the drag of the ama and the foils. Another aspect: I think when the foil is to weather, it does not depend on the centre of gravity but on the centre of buoyancy whether the boat is non-heeling or not. A catamaran of a given beam could achieve non heeling with a single canted board to windward but not with one to leeward.</P> <P>(page 7) <HR> </P> <CENTER> <P><IMG SRC="p8.gif" WIDTH="290" HEIGHT="109" ALIGN="BOTTOM" ALT="2nd Bruce Foiler drawing" BORDER="0"></P> </CENTER> <P>Now one can build a Bruce Foiler which is balanced out on the weather tack (foil to weather) and under-balanced out on the lee tack. Take one reef in and the boat will be over-balanced out on the weather tack. The ama will be pressed into the water. The centre of buoyancy moves to weather till an equilibrium, the non-heeling state again, is achieved. In a gust, the boat should sink evenly, and not only the ama, as the foil force increases. If the ama pops out in a wave the boat is overbalanced out and the ama 1S very quickly pushed back in the water. It should be possible to build a quite safe offshore Bruce Foiler.</P> <P>The rudder system used on Charente Maritime 11 and proposed by you in publication 87 has, in my opinion, one major disadvantage: when caught in irons, it will be difficult to get the boat sailing again. My proposal is best suited for small catamarans with a kick-up rudder system. You simply take asymmetric rudder blades and only use the leeward one. The chords should not be parallel but have a tow out of about S degrees. The tow out depends on the chosen profile. The weather rudder blade should develop no or only little lift when the other is at its optimum L/D ratio. For tacking you simply push down the weather rudder blade, tack, and pull up the other. Most of the time the boat will sail with only one rudder blade and less resistance. In "Design for Fast Sailing" it is said that "the driving component, on a windward course, falls of as the square of the cosine of the angle of tilt from the vertical". The projected sail area and the angle of attack are proportional to the cosine of the tilt (or heeling) angle. When the angle of attack is kept constant by sheeting in or falling off, the sail force should fall off only with the cosine of the angle of tilt.</P> <P>A few months ago I began studying biology. In a lecture a professor mentioned that the whales used to communicate over hundreds of miles using low frequency sounds. Nowadays this frequency of about 12Hz is occupied by the ship's diesel motors. Perhaps it is possible to build an anti-collision alarm using a microphone tuned in to this frequency.</P> <DIV ALIGN="RIGHT"> <P>Robert Beigler</P> </DIV> <P>(page 8)</P> <P><A HREF="#contents">return to Contents | </A><A HREF="101b.html">Next page</A> </BODY> </HTML>