DOCSLIB.ORG

Mast Tuning a Catalina 25 by Bill Holcomb

Total Page：16

File Type：pdf, Size：1020Kb

Download full-text PDF Read full-text

Load more

The Technical Manuals were produced over a period encompassing the 1970s, 1980s and 1990s. As such, solicitations for updates are no longer being accepted, and the manuals are offered to Association Members as a courtesy by the Catalina 25/250 National Association. Special thanks go to Bill Holcomb for making these copies available for our use. The 2004 – 2005 Officers Catalina 25/250 National Association 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 1 6 17 18 19 20 21 22 - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - Mast Base Organizer Skippers who want to modify their halyards and other lines so that all (or some) are lead from the mast base back on the cabin top for single handed sailing and for ease of handling often use stainless steel plates with attachment holes for shackling blocks. Two sources of these plates are: M&E Supply Company 1-800-541-6501 And Bill Henshaw 111-SW 16 St, Southport, NC 28465-7308 - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - Bill Holcomb wrote the following article on behalf of Mike Leyden and other skippers thinking about changing their swing keel to the new wing keel. Mike Leyden's Wing Keel Installation by Bill Holcomb During his fall haul-out, Mike Leyden didn't get his Catalina 25s keel fully retracted before the boat settled onto the trailer. The crunching sound that came from the keel trunk as the boat settled was alarming to say the least. Mike assessed the damage and found that the cable attachment fitting on the keel end of the cable had "flopped over" rather than finding its way into the cable hole. The resulting damage to the keel trunk was enough to convince Mike that he wanted to change to the wing keel by using the retro-fit option that is offered by Catalina. Mike and I made plans to install the new wing keel "sometime" in the spring. And, on the weekend of March 26/27 we did just that. What follows are some thoughts that Mike and I have following the installation: First of all, Mike had an almost perfect facility to do the work in. He works at a medium sized machine shop that has several overhead cranes. These cranes made moving keels and lifting the boat much easier than would have been otherwise possible. The cranes also made positioning the boat over the keel trunk (and the holes we'd drilled) very easy. The boat could be moved a little ahead, or to the right, or a little down at the bow, etc. The arrangement that Mike devised was to use two overhead cranes, one to lift the forward part of the boat and the other to lift the aft half. He prepared a nine foot long "spreader" bar to keep the 4 inch nylon straps from exerting too much pressure against the sides of the boat, and also fashioned two connecting straps to keep the lifting straps from slipping toward either end of the boat. Second, after you've received the keel, bolt hole template, resin, fiber-fil, etc.; think, think, think. What are the steps that you expect to go through, and in what order. Things like: A - Bracing the old keel so that it won't "flop" over. B - How will you lift the boat off of the old keel. You need to be able to lift the boat up about two and a half feet altogether. 23 C - Where will you put the old keel, and how will you get it there after it's been unbolted from the boat. D - How will you get the new wing keel under the boat. E - Do you have a long enough drill bit to drill the six 3/4 inch holes for the keel bolts. And, do you have a long 1/4 inch and 1/2 inch drill bit to drill a pilot hole and second hole before you drill the 3/4 inch final hole. F - Do you have a method for "sanding" off all of the old bottom paint that has been painted on the bottom of the boat and in the keel trunk. This was the hardest single job in the whole process for us. G - How will you make sure that the boat is lowered onto the keel bolts without a "near miss" and subsequent damage. H - How will you stir the fiber-fil (the bedding compound that makes a water-tight seal between the keel and boat) and its hardener. The fiber-fil has the consistency of green tooth paste and needs to be thoroughly mixed with hardener to set up correctly. I - What kind of hole in the cabin floor will you cut and how will you cut the holes so that you will be able to put the washers and nuts on the keel bolts. And, of course, how will you want to finish the hole in the cabin floor after the keel is bolted to the bottom. J - How will you "fair" the junction between the flange on the wing keel and the bottom of the boat. What do you want this part of the boat to look like when you're through. K - Will you need to drill new holes in the trailer bunks support pieces to accommodate the taller keel. Well, you can see that the 5 "P's" (Prior Planning Prevents Poor Performance) really come into play with this project. For us, everything went pretty smoothly. With the two cranes ready, Mike unbolted the old keel hangers. The keel was resting on the trailer in its normal "travel" position. Mike had also made an extra brace to keep the keel from flopping, and had already removed the keel cable winch from inside the boat. We then lifted the boat straight up about a foot or so. Mike pulled the keel cable out of the hole and we used a forklift with a ball on one fork to move the trailer forward and out from under the boat. We now used a boom-crane to lift the old keel off of the trailer, and then positioned the trailer back under the boat. One little surprise that we had when we lifted the boat off of the old keel was that we had not gotten the slings just right and the boat tilted a bit when lifted. When we lowered the boat back onto the bunks to sand the bottom, it was necessary to re-position the slings so that the boat would lift straight up and not tilt. This took a couple of tries lifting the boat off of the bunks to get the slings just right. Now Mike loaded the old swing keel onto the forks of the fork lift and we took the keel out into the yard and deposited it on a couple of 6 X 6s. Mike says that if anyone wants the keel that you can have it for free if you pay the freight to haul it home to you. It's in very good condition. Back inside, we lowered the boat and began the work of "sanding" the bottom paint from the keel trunk and from about six inches of the boats bottom around the keel trunk. As I said, this was the toughest single job. To sand the inside of the keel trunk Mike used a circular "Scotch- 24 brite" type of pad that rotated on the end of a 1/4" die grinder. He wore out eight or nine of these. A circular sanding pad for a 4" sander with 6" discs (without a backing pad so the disc would flex) was used for the boats bottom. We had thought that 80 grit paper would be more than enough, but quickly found that the 10 or so layers of bottom paint were so tough that 24 grit was all that would really do the job. Boy were we a mess, especially Mike. Throughout the sanding operation both of us wore respirators. The little white cloth masks would not have been enough with all of the fine dust that the bottom paint made. When the sanding was done, we cleaned off the sanded areas with an air nozzle and then with acetone. Now it was time to mark and then drill the bolt holes. We used the template that Catalina supplied. It is a fiberglass template that comes fitted to the new keel and has the bolt holes in just the right position. The template has a hump that fits into the keel cable hole. This anchors the template and makes marking and drilling the keel bolt holes an easy job if your drill bits are long enough. Mike ran the drill while I lined him up vertically from the side of the boat. The 1/4 inch drill bit was long enough to drill through both the top of the keel trunk and through the cabin floor. That way, we could see just where in the cabin the floor needed to be removed. Once the 1/4 inch pilot holes were in, we drilled the holes out to the recommended 3/4 inch size. This done, we both got inside the cabin and used a hole saw to cut holes in the floor over the bolt holes. Mike has a dinette model, so two of the holes were under the aft seat. One surprise that we had at this point was that the fourth hole aft was too close to the forward side of the aft seat. This meant that we had to use a jig-saw to cut an opening for the hole-saw.
Recommended publications
  • Catalina 22 - an All-Around Champion

    Catalina 22 - an All-Around Champion

    Catalina 22 - An All-Around Champion A 40 year history of the Builder, the Class, and the People who Love This Boat! 1969 - 2009 Prepared by Rich Fox Catalina 22 National Sailing Association First Release - November 2009 MILESTONE YEARS OF THE CATALINA 22 July 1969 The Catalina 22 is built in North Hollywood, California. Frank Butler hopes to build 100 boats if all goes well. August 1972 A Catalina 22 Race is held in California and is tagged by Frank Butler as the “Catalina 22 Nationals”. The Catalina 22 National Sailing Association is formed. February 1975 Hull number 5000 is built. February 1980 SAIL Magazine names the Catalina 22 as “Trailerable Boat of the Decade”. September 1980 Hull number 10,000 is built. The Catalina 22 is built in plants in California, Florida, England, Australia and Canada. 1985 The Catalina 22 “New Design” is introduced for the 1986 model year. February 1990 Hull number 15,000 is built. January 1995 The Catalina 22 MkII is introduced, beginning with hull number 15,348, and features an enlarged deck, transom and interior. February 1995 The Catalina 22 is named as one of the five charter members to the Sailboat Hall of Fame. Fall 2001 The Catalina 22 National Sailing Association approaches Frank Butler about building a new Catalina 22 that more closely matches the design of the original Catalina 22. June 2004 The Catalina 22 Sport is built, beginning with hull number 15,540. The Sport and MkII models are manufactured in Woodland Hills, California. July 2009 The Catalina 22 MkII and Sport remain in production 40 years later with relocation of manufacturing facilities to Largo, Florida.
  • PHRF MASTER PHRF Master Nov 2017.Xlsx 2/15/18

    PHRF MASTER PHRF Master Nov 2017.Xlsx 2/15/18

    Sail BoatName BoatType Skipper Club PHRF 276 CORSAIR 31-1D Kersey, Bo AYC -51 215 TRIBOLOGY F31 HORTON, P Casey, D -21 24 LAGNIAPPE F25C HOWARD,J AYC 9 80x F28 AYC 15 60 ARANA de AGUA F28R MAKI,V. AYC 15 163 CHECKMATE STILETTO 23 BUCK,P. AYC 15 1x LADY LEE STILETTO 27 STEVENS,R. AYC 21 22x Corsair 750 Kuc, J AYC 36 356 TRYST F27 AGEE,R AYC 60 246x Warrior 11 Metre Henrickson, James AYC 69 3580 Voodoo Beneteau First 35 BARLOW, ROBERT AYC 78 25527 ZEN 2 BENETEAU First 36.7 BOGGUS,W AYC 78 105-1 J 105 J/105 LEMMONS, K 78 307J J/105 SPURLIN,S AYC 78 675 J/105 LEMONS, KEN AYC 84 1051 Xcitation J/105 Lemons,K AYC 84 30J J/92 SPURLIN, S AYC 90 7 DUTCH COMFORT X-TREME 25 MARSH, PETER AYC 90 J/100 McDonald, Bruce AYC 93 178 COYOTE MELGES 24 ROCHARD,E. AYC 93 22 DANGEROUSLY VIPER 640 SIRCELY, JOE 96 601 VIPER 640 PAYET,FELIPE AYC 96 180 OBESSION OLSON EDWARDS,J. AYC 99 8143 OLSON 30 NEWMAN,J AYC 99 22586 LOWRIDER OLSON 30 COBB,G. AYC 99 149O BLOWN ASSETS OLSON 30 SMITH,T. AYC 99 MISTRAL ELITE 37 CUSHING, DORAN AYC 102 103 THE STIG VIPER 640 PAYET, FELIPE AYC 102 102x ANIMAL VIPER 640 JONES, JEFF & CARRIE AYC 102 42V GIDDY UP VIPER 640 VLANDINGHM AYC 105 31198x Red Sky C&C 37 PETERSON, BAY AYC 108 145 GODZILLA J/29 Tillinghast, J AYC 108 149 IMAGINE J/29 MEYERS,R Romberg, M.
  • Fleet Boat Sail # Owner Keel Rig Mods Base PHRF Adjust Your

    Fleet Boat Sail # Owner Keel Rig Mods Base PHRF Adjust Your

    Boat Information PHRF Rating Adjustments All Your Jib O.S. Jib Dacron O.S. Base Assigned 130% Roller Non IB Fleet Boat Sail # Owner Keel Rig Mods Adjust Head <130 Cruising Spin PHRF PHRF to Furler Spin Prop Sail % Blue / Pole Rating 145% White -3 +6 +9 +3 +6 +12 -3 +6 Blue/White Cape Dory Typ. TY 72 Harrington Fixed Std No 276 27 303 6 3 6 12 Blue/White Capri 26 14 Smith Fin Std No 237 27 264 6 3 6 12 Blue/White Catalina 22 2191 Kroh Swing Std No 270 12 282 12 Blue/White Catalina 22 Mk-II 15351 Walker Wing Std No 273 12 285 12 Blue/White Catalina 22 Sport 15582 Fox Swing Std No 252 12 264 12 Blue/White Catalina 25 2925 Gummer Swing Std No 243 18 261 6 12 Blue/White Catalina 25 3736 Hollingsworth Swing Tall No 240 27 267 6 3 6 12 Blue/White Catalina 25 4639 George Swing Std No 243 18 261 6 12 Blue/White Catalina 25 5101 Hickok Swing Std No 243 18 261 6 12 Blue/White Catalina 25 5130 Earnhart Swing Std No 243 18 261 6 12 Blue/White Catalina 25 5884 Kelly Wing Tall No 246 21 267 3 6 12 Blue/White Catalina 250 406 Alyea Swing Std No 243 21 264 3 6 12 Blue/White Hunter 216 H216 Zimmowitch CB Std No 222 18 240 6 12 Blue/White Hunter 23 788 Lessick Swing Std No 246 18 264 6 12 Blue/White Hunter 23 H23 Kirch Swing Std No 246 18 264 6 12 Blue/White Hunter 23.5 H23.5 Elmore CB Std No 252 30 282 9 3 6 12 Blue/White Hunter 240 24489 Merriman Swing Td No 243 30 273 9 3 6 12 Blue/White Hunter 26.5 167 Crowther Wing Std No 189 27 216 6 3 6 12 Blue/White Lindenberg 22 22189 McGarvey Retract FR No 216 0 216 Blue/White MacGregor 26 4393 Grant Swing Std
  • Sailing Trans-Atlantic on the USCG Barque Eagle

    Sailing Trans-Atlantic on the USCG Barque Eagle

    PassageRite of Sailing Trans-Atlantic On The USCG Barque Eagle odern life is complicated. I needed a car, a bus, a train and a taxi to get to my square-rigger. When no cabs could be had, a young police officer offered me a lift. Musing on my last conveyance in such a vehicle, I thought, My, how a touch of gray can change your circumstances. It was May 6, and I had come to New London, Connecticut, to join the Coast Guard training barque Eagle to sail her to Dublin, Ireland. A snotty, wet Measterly met me at the pier, speaking more of March than May. The spires of New Lon- don and the I-95 bridge jutted from the murk, and a portion of a nuclear submarine was discernible across the Thames River at General Dynamics Electric Boat. It was a day for sitting beside a wood stove, not for going to sea, but here I was, and somehow it seemed altogether fitting for going aboard a sailing ship. The next morning was organized chaos. Cadets lugged sea bags aboard. Human chains passed stores across the gangway and down into the deepest recesses of the ship. Station bills were posted and duties disseminated. I met my shipmates in passing and in passageways. Boatswain Aaron Stapleton instructed me in the use of a climbing harness and then escorted me — and the mayor of New London — up the foremast. By completing this evolution, I was qualified in the future to work aloft. Once stowed for sea, all hands mustered amidships.
  • Mainsail Trim Pointers, Reefing and Sail Care for the Beneteau Oceanis Series

    Mainsail Trim Pointers, Reefing and Sail Care for the Beneteau Oceanis Series

    Neil Pryde Sails International 1681 Barnum Avenue Stratford, CT 06614 203-375-2626 [email protected] INTERNATIONAL DESIGN AND TECHNICAL OFFICE Mainsail Trim Pointers, Reefing and Sail Care for the Beneteau Oceanis Series The following points on mainsail trim apply both to the Furling and Classic mainsails we produce for Beneteau USA and the Oceanis Line of boats. In sailing the boats we can offer these general ideas and observations that will apply to the 311’s through to the newest B49. Mainsail trim falls into two categories, upwind and downwind. MAINSAIL TRIM: The following points on mainsail trim apply both to the Furling and Classic mainsail, as the concepts are the same. Mainsail trim falls into two categories, upwind and downwind. Upwind 1. Upwind in up to about 8 knots true wind the traveler can be brought to weather of centerline. This ensures that the boom will be close centerline and the leech of the sail in a powerful upwind mode. 2. The outhaul should be eased 2” / 50mm at the stopper, easing the foot of the mainsail away from the boom about 8”/200mm 3. Mainsheet tension should be tight enough to have the uppermost tell tail on the leech streaming aft about 50% of the time in the 7- 12 true wind range. For those with furling mainsails the action of furling and unfurling the sail can play havoc with keeping the telltales on the sail and you may need to replace them from time to time. Mainsail outhaul eased for light air upwind trim You will find that the upper tell tail will stall and fold over to the weather side of the sail about 50% of the time in 7-12 knots.
  • Sail Trimming Guide for the Beneteau 37 September 2008

    Sail Trimming Guide for the Beneteau 37 September 2008

    INTERNATIONAL DESIGN AND TECHNICAL OFFICE Sail Trimming Guide for the Beneteau 37 September 2008 © Neil Pryde Sails International 1681 Barnum Avenue Stratford, CONN 06614 Phone: 203-375-2626 • Fax: 203-375-2627 Email: [email protected] Web: www.neilprydesails.com All material herein Copyright 2007-2008 Neil Pryde Sails International All Rights Reserved HEADSAIL OVERVIEW: The Beneteau 37 built in the USA and supplied with Neil Pryde Sails is equipped with a 105% non-overlapping headsail that is 337sf / 31.3m2 in area and is fitted to a Profurl C320 furling unit. The following features are built into this headsail: • The genoa sheets in front of the spreaders and shrouds for optimal sheeting angle and upwind performance • The size is optimized to sheet correctly to the factory track when fully deployed and when reefed. • Reef ‘buffer’ patches are fitted at both head and tack, which are designed to distribute the loads on the sail when reefed. • Reefing marks located on the starboard side of the tack buffer patch provide a visual mark for setting up pre-determined reefing locations. These are located 508mm/1’-8” and 1040mm / 3’-5” aft of the tack. • A telltale ‘window’ at the leading edge of the sail located about 14% of the luff length above the tack of the sail and is designed to allow the helmsperson to easily see the wind flowing around the leading edge of the sail when sailing upwind and close-hauled. The tell-tales are red and green, so that one can quickly identify the leeward and weather telltales.
  • The Weather Helm Issue (Rev 20 02 2020)

    The Weather Helm Issue (Rev 20 02 2020)

    Corbin 39 – the weather helm issue (rev 20 02 2020) Synopsis The subject of weather helm comes up repeatedly when discussing the Corbin 39 and not all of the folklore is justified. This note attempts to summarise the issue and to relate it to sufficient evidence, and to qualitative theory, that we can be reasonably certain of the situation. Remember - It is possible to overpower a yacht and induce weather helm, what we are trying to do is identify excessive weather helm. The key take-away is that the excessive weather helm was a genuine issue, which affected all the mk1 cutters irrespective of whether they were equipped with the taller double-spreader mast or the shorter single-spreader mast, provided that the mast was set in the intended aft mast position. Perhaps this was worse in the mk1 tallmast vs the mk1 shortmast, but we are not at all certain of that. All the mk1’s that had the forestay relocated onto a 3-foot long bowsprit were later able to alleviate this to an extent. The mk 1’s that have reduced the area of their main by shortening the mainsail boom & foot (or used in-mast furling) have reportedly completely eliminated this weather helm. All other versions including the mk1 ketches and all the mk2 cutters & ketches appear to be completely unaffected. This is the first openly published version of this analysis. Previous drafts were incomplete and drew erroneous conclusions in some areas due to an absence of reliable data. That has now been overcome as further evidence has come forwards, and so there are material differences between this version and previous drafts.
  • Rigid Wing Sailboats: a State of the Art Survey Manuel F

    Rigid Wing Sailboats: a State of the Art Survey Manuel F

    Ocean Engineering 187 (2019) 106150 Contents lists available at ScienceDirect Ocean Engineering journal homepage: www.elsevier.com/locate/oceaneng Review Rigid wing sailboats: A state of the art survey Manuel F. Silva a,b,<, Anna Friebe c, Benedita Malheiro a,b, Pedro Guedes a, Paulo Ferreira a, Matias Waller c a Rua Dr. António Bernardino de Almeida, 431, 4249-015 Porto, Portugal b INESC TEC, Campus da Faculdade de Engenharia da Universidade do Porto, Rua Dr. Roberto Frias, 4200-465 Porto, Portugal c Åland University of Applied Sciences, Neptunigatan 17, AX-22111 Mariehamn, Åland, Finland ARTICLEINFO ABSTRACT Keywords: The design, development and deployment of autonomous sustainable ocean platforms for exploration and Autonomous sailboat monitoring can provide researchers and decision makers with valuable data, trends and insights into the Wingsail largest ecosystem on Earth. Although these outcomes can be used to prevent, identify and minimise problems, Robotics as well as to drive multiple market sectors, the design and development of such platforms remains an open challenge. In particular, energy efficiency, control and robustness are major concerns with implications for autonomy and sustainability. Rigid wingsails allow autonomous boats to navigate with increased autonomy due to lower power consumption and increased robustness as a result of mechanically simpler control compared to traditional sails. These platforms are currently the subject of deep interest, but several important research problems remain open. In order to foster dissemination and identify future trends, this paper presents a survey of the latest developments in the field of rigid wing sailboats, describing the main academic and commercial solutions both in terms of hardware and software.
  • ANSWERS to Goddard Sailing Association

    ANSWERS to Goddard Sailing Association

    ANSWERS to Goddard Sailing Association (Chesapeake Bay) online-test QUESTION 1: Identify the following parts of a sailboat below: centerboard forestay port shroud tabernacle toping lift boom vang painter winch starboard boom mast tiller A. Boom B. Forestay C. Shroud D. Mast E. Winch F. Centerboard G. Tabernacle H. Tiller I. Topping lift J. Painter K. Port L. Starboard M. Boom vang QUESTION 2: Identify the following sails and parts of a sail below: luff leach clew bow batten head tack foot mainsail stern telltale jib A. mainsail B. jib C. clew D. tack E. head F. leach G. luff H. foot I. batten J. telltale K. stern L. bow QUESTION 3: Match the following items found on a sailboat with one of the functions listed below. mainsheet jibsheet(s) halyard(s) fairlead rudder winch cleat tiller A. Used to raise (hoist) the sails HALYARD B. Fitting used to tie off a line CLEAT C. Furthest forward on-deck fitting through which the jib sheet passes FAIRLEAD D. Controls the trim of the mainsail MAINSHEET E. Controls the angle of the rudder TILLER F. A device that provides mechanical advantage WINCH G. Controls the trim of the jib JIBSHEET H. The fin at the stern of the boat used for steering RUDDER QUESTION 4: Match the following items found on a sailboat with one of the functions listed below. stays shrouds telltales painter sheets boomvang boom topping lift outhaul downhaul/cunningham A. Lines for adjusting sail positions SHEETS B. Used to adjust the tension in the luff of the mainsail DOWNHAUL/CUNNINGHAM C.
  • Sailing Course Materials Overview

    Sailing Course Materials Overview

    SAILING COURSE MATERIALS OVERVIEW INTRODUCTION The NCSC has an unusual ownership arrangement -- almost unique in the USA. You sail a boat jointly owned by all members of the club. The club thus has an interest in how you sail. We don't want you to crack up our boats. The club is also concerned about your safety. We have a good reputation as competent, safe sailors. We don't want you to spoil that record. Before we started this training course we had many incidents. Some examples: Ran aground in New Jersey. Stuck in the mud. Another grounding; broke the tiller. Two boats collided under the bridge. One demasted. Boats often stalled in foul current, and had to be towed in. Since we started the course the number of incidents has been significantly reduced. SAILING COURSE ARRANGEMENT This is only an elementary course in sailing. There is much to learn. We give you enough so that you can sail safely near New Castle. Sailing instruction is also provided during the sailing season on Saturdays and Sundays without appointment and in the week by appointment. This instruction is done by skippers who have agreed to be available at these times to instruct any unkeyed member who desires instruction. CHECK-OUT PROCEDURE When you "check-out" we give you a key to the sail house, and you are then free to sail at any time. No reservation is needed. But you must know how to sail before you get that key. We start with a written examination, open book, that you take at home.
  • The Way of the Sea

    The Way of the Sea

    1 The Way of the Sea Cheney Duvall stared up at the great clouds of soaring sail, though her eyes watered from the sun and salt sting. The Brynn Annalea had found a tail of the northeast trade winds, strong and hot, to wend her fast down Baja and push her easily over the Tropic of Cancer. Her sharp prow knifed the water, the jib with the lucky shark’s fin mounted on it splashing in the wave crests. She was a beautiful thing, fast, sharp-hulled, streamlined, proud. And dangerous. Cheney shouted up at Shiloh, and he was shouting back down at her. Neither of them could possibly hear the other, but both of them kept on. “You idiot! Come down from there this instant! You are going to fall and die!” Cheney shrieked. He made an impatient gesture—Get below, you dumb girl!— which made Cheney’s heart almost stop, for he had let go with one arm to make jabbing “get below” motions to her. Twelve seamen were perched along the bucking, straining yard, feet kicked back against the footrope, bellies pressed against the yard, hands gathering up the heavy canvas. Cheney watched, horrified, as they struggled to roll the great main royal sail around the yard. Finally it was wound as neatly as thread on a spool, and the sailors, with strong and agile movements, passed lengths of rope around sail and yard and made it fast with hitches. One by one they started edging back along the yard, making for the weather shrouds to scamper down.
  • An Autonomous Wing-Sailed Catamaran Ph.D.Thesis by Gabriel H. Elkaim the Wingsail Wingsail Description Wing Versus Sail

    An Autonomous Wing-Sailed Catamaran Ph.D.Thesis by Gabriel H. Elkaim the Wingsail Wingsail Description Wing Versus Sail

    An Autonomous Wing-Sailed Catamaran Ph.D.Thesis by Gabriel H. Elkaim The following information has been extracted from the thesis submitted by Dr. Gabriel Elkaim to Stanford University, and for which he was awarded his Ph.D. The full thesis, which can be viewed at http://www.soe.ucsc.edu/~elkaim/Documents/GabrielElkaimThesis01.pdf (and an extract published in the AYRS’s Journal ‘Catalyst’ which can be found at http://www.soe.ucsc.edu/~elkaim/Documents/Catalyst_BoatArticle.pdf), describes the Atlantis project, whose aim was the design, development, and experimental testing of an autonomous wind- propelled marine craft. The parts printed here are the ones which may be of interest to members of the JRA These extracts are re-published from the AYRS Journal “Catalyst” by kind permission of Dr. Gabriel and of the Amateur Yacht Research Society. Please note that the figures are numbered as in the original document. The Wingsail The most visibly unique aspect of the Atlantis project is the wingsail propulsion system, as shown in Figure 5-1. The design considerations and goals are: equivalent performance to the original sail system, low actuation force, and the ability to precisely control the resulting system. A sloop rig sail can achieve a maximum lift coefficient of 0.8 if the jib and sail are perfectly trimmed. Realistically, an operating maximum lift coefficient is 0.6. The design goal of the Atlantis wing is to achieve a maximum lift coefficient of 1.8. Since this allows the wing to generate three times the force of an equivalently sized sail, the wing area is reduced to one third of the area of the original sails.