DOCSLIB.ORG

Developed Specifically Around the Semi Rigid Wing Sail, the K8 Sport Claims to Be a 'Game Changing' Design. ANDI ROBERTSON S

Total Page：16

File Type：pdf, Size：1020Kb

Download full-text PDF Read full-text
Developed Specifically Around the Semi Rigid Wing Sail, the K8 Sport Claims to Be a 'Game Changing' Design. ANDI ROBERTSON S K8 SPORT BOAT TEST GAME CHANGER Developed specifically around the Semi UNDER SAIL 9/10 Rigid Wing sail, the K8 Sport claims to be a «««««««««« ‘game changing’ design. ANDI ROBERTSON sifts through the rhetoric and finds 1 2 real substance behind the claim ANDI ROBERTSON ALL IMAGES: his three-to-four person is effectively nearly eliminated and the Narrow static waterlines are achieved by 1. The spinnaker HULL AND DECK 8/10 the big, open cockpit, the cutouts for the is on a single SPECIFICATIONS lifting keelboat turns design wing section creates a proportionately slab sides and a gently curved bottom line and so is «««««««««« radiused main track and the pod for the LOA: 7.99m Displacement: 900kg convention on its head. faster, more attached and smoother section. Form stability is a primary easy to hoist The hull has a very powerful form main controls. Sailing with four there is Beam: 2.55m Mainsail: 29sq m Boasting the world’s flow over the foil. Camber control goal, that means the boat is sailed legs 2. The small, with chunky forward sections and the plenty of space to work, albeit slightly self-tacking jib Draught: 2.1m Jib: 12sq m first production is easily and smoothly achieved. in by the four crew, maximising appeal is the result of beam carried quite far forward. The more static work than say the SB20 or Raised keel: 1.65m Asymmetric: 78sq m Tsemo-rigid wing sail, the hull has The benefits in performance and to experienced owners who no longer much testing chine runs full length, right into the Melges or J80, where it is all about crew been designed to optimise the power handling are significant. The sail is want a big crew, high maintenance bills 3. Despite bow, maximising the effective waterline weight on the rail and dynamic, fast experimenting the rig delivers and blend that with powered up earlier and remains almost or to be racing an out-dated design. with different beam, but so too the chine is relatively sail controls in manoeuvres. There is an an ease of handling intended to make completely stable as the centre of effort Boat number one is going to the US; shapes for the high above the waterline indicating that integrated space for a cooler box for the leading edge, the a new generation of performance hardly moves at all. Hence rudder there has also been significant interest mast is actually it is designed to sail with some heel. beers, fitting in the void above the keel sailing accessible to the masses. corrections are minimised. Heeling from Etchells and Dragon owners. A fairly conventional That reverse bow keeps ample volume stub – an obvious Aussie influence! moment is reduced. The net effects are big attraction is that two boats can 4. The two sail forward to induce early planing and membranes are CONCEPT 9/10 a boat that is faster in any given wind be top and tailed into a container. set on parallel minimise slamming. Otherwise the RIG AND APPENDAGES 9/10 strength and easier to control. Sheet The K8’s hull is designed by tracks in the lines are relatively straight with a gentle, «««««««««« aft, outer edge «««««««««« The concept behind the Semi Rigid loads on the mainsail are minimal; you Argentina-based Nicolas Goldenberg of the counter- smooth and quite straight rocker. Appendages are straightforward. Wingsail (SRW) is far from new, having are controlling the angle of attack and for G Yacht Design, whose biggest and rotating mast The hull is moulded in e-glass The lift T shape keel has a 230kg bulb 5. The central first been developed by Australian the flow over the sail. And subsequent most recent success is the series Classe control box throughout with carbon reinforcements on it and is raised on a simple crane, brothers Greg and Patrick Johnston learning on jib design and sheeting Mini RG650, which took hold in South from where the only in key areas, primarily on top reducing the draft from 2.1m to 1.65m. sail shape can during the 1980s, and trialled with angle has led to a small self tacking America as an entry level series boat, be adjusted of the ring frames and the hog. Twin rudders are set with fixed angles great success in 18ft Skiffs. Predictably jib with a wide sheeting angle. and Valencia, where a fleet of 15 is based. 6. Camber is The deck itself is pretty standard; a and give the optimum mix of grip though it was banned, and the prototype The hull shape is powerful and There, the unique combination of the K8 controlled through small wedge shaped coach roof allows a at heeled angles and shallower draft mast rotation consigned to Greg Johnston’s garage. uncompromising. The reverse sheer and its SRW are attracting the attention and is crucial to little more living area. Production boats at the cost of slightly more drag. But with the 33rd America’s Cup in bow allows more volume in the forward of pros and there’s a definite buzz depowering and will have a pipecot either side, and a But the rig is the key and while it powering up Valencia and BMW Oracle’s wing sections, promoting maximum lift. about the class beginning to emerge. little galley. Otherwise the key feature is might look complex, in fact it is both technology leading to where we are now, development has taken off. The Semi Rigid Wing cleverly uses a counter rotating mast to induce a foil shape by causing the battens on the leeward side to compress and curve, simultaneously setting the battens on the windward side in tension and therefore holding them straighter. The thickness or depth of the foil is controlled by the angle of rotation of the mast. The two membranes are set on parallel tracks on the aft, outer edge of the mast, which produce a near perfect, flush interface 3 4 5 6 between the mast and foil. The mast drag 72 Yachts & Yachting February 2016 yachtsandyachting.co.uk February 2016 Yachts & Yachting 73 the mast rotation angle, flattening off as windspeed increases. This is a vital control. And at the front of the pod is the upper section camber control. The self-tacking jib is set at an angle of about 12 degrees, much more open than many grand prix racers. That’s because the jib is doing a completely different job here; in essence, you are not squeezing and accelerating the air through the slot to attach the flow to the leeward side of the main, trying to create a single element foil, instead the SRW foil is doing all that. So the jib’s main purpose is simply to help the bow through manouevres. The mainsail’s square top profile requires twin running backstays. The tail runs under the cockpit and comes back to a Spinlock clutch on the cockpit side for coarse setting; there suprisingly simple and very clever. Above single line is more like a vang, dumped is also a 4:1 fine tune on the pod. No conventional The semi rigid foil is formed by the mainsheet in extreme gusts or bear aways. Mostly The 78sq m kite is hoisted on twin membrane ‘sails’ tapered back to a means the helm when you are overpowered you poke a single line. The tack goes out sails without single leech. The carbon mast counter touching a rope the nose up and sail higher with the automatically to the end of the fixed rotates to control the camber of the jib pretty much inside out, multihull sprit. All deckgear is Harken. wing. Total rig weight is about 55kg all style, but by all accounts this produces up with just 18kg in the mast itself. This a nice 50-60m gain to windward. UNDER SAIL 8/10 is not a rotating wing mast, so does not The controls box is a central pod, «««««««««« provide lift in the same way. Despite incorporating the 8:1 traveller control, Despite there being no more than a few experimenting with different shapes which is essentially the accelerator, knots of breeze for our test, the K8 Sport for the leading edge, there is no real controlling the angle of the sail. It was breathtaking. We sailed from the departure from convention, as the width is the aft-most control on this little moment we got out of Valencia’s Real of the mast only really governs camber. bank in the middle of the cockpit, Marina Juan Carlos and never stopped. essentially for the wing trimmer who It’s uncanny, all the time sailing at LAYOUT AND CONTROLS 8/10 is beside the helm (the helm touches windspeed. With a little human induced «««««««««« no strings). Next forward control is heel the boat moved brilliantly, burbling The efficiency of the SRW is governed Below the fine tune backstay control, then along with a beautiful smooth wake. Despite only the by the angle of attack, the angle of faintest zephyrs the lines, which control lower section The helm is positive with a heavier the boom to the wind rather than the for our test the camber control (what would be the feel but you are not making constant boat felt nicely leech of the sail and so there is no powered up outhaul on a conventional main). Next course adjustments. This is much conventional mainsheet. Instead the forward is the camber control governing more about setting your course angle. In light airs you are sailing at about 40 degrees upwind. And all the time we were making 2.8 to 3.5 knots in only the faintest of zephyrs, but the boat felt nicely powered up.
Load more

Recommended publications
  • How the Beaufort Scale Affects Your Sail Plan
    How the Beaufort scale affects your sail plan The Beaufort scale is a measurement that relates wind speed to observed conditions at sea. Used in the sea area forecast it allows sailors to anticipate the condition that they are likely to face. Modern cruising yachts have become wider over the years to allow more room inside the boat when berthed. This offers the occupants a large living space but does have an effect on the handling of the boat. A wide beam, relatively short keel and rudder mean that if they have too much sail up they have a greater tendency to broach into the wind. Broaching, although dramatic for those onboard, is nothing more than the boat turning into the wind and is easy to rectify by carrying less sail. If the helm is struggling to keep the boat in a straight line then the boat has too much ‘weather helm’ i.e. the boat keeps turning into the wind- in this instance it is necessary to reduce sail. Racer/cruisers are often narrower than their cruising counter parts, with longer keels and rudders which mean they are less likely to broach, but often more difficult to sail with a small crew. Cruising yachts often have large overlapping jibs or genoas and relevantly small main sails. This allows the sail area to be reduced quickly and easily simply by furling away some head sail. The main sail is used to balance boat as the main drive comes from the head sail. Racer cruisers will often have smaller jibs and larger main sails, so reducing the sail area means reefing the main sail first and using the jib to balance the boat.
    [Show full text]
  • 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.
    [Show full text]
  • Designing Sails Since 1969
    SAILRITE SAIL KITS Designing sails since 1969. Catalina 30 Tall Rig Mainsail Kit by Frederick Leroy Carter F 31R Screecher Kit by Patrick Pettengill Capri 18 Main & Jib Sail Kits by Brent Stiles “ We built this sail ourselves!” Custom Lateen Main Kit by Steve Daigle -Karen Larson Building your own sail is a very rewarding and satisfying Each kit comes with the sail design data and a set of instructions experience. Not only is there a real sense of accomplishment, and illustrations that have been perfected from over 40 years of but the skills developed in the process will make you a more self- experience and feedback. Sail panels are pre-cut, labeled and reliant sailor. Sailrite makes the process very easy and affordable numbered for easy assembly. Panel overlap and hemming lines from start to finish by providing sail kits that include materials come plotted on each panel and double-sided tape is included used by professional sailmakers at up to 50% less the cost! to adhere panels together prior to sewing to ensure that draft and shape are maintained during construction. Batten pockets, Sailrite uses state-of-the-art design programs and hardware to windows, draft stripes, reef points, and other details will also prepare each kit. Sail panels and corner reinforcements are all come plotted on the appropriate panels if required for your sail. computer-cut and seaming lines are drawn along the edges. Draft, twist, and entry and exit curves are all carefully calculated, controlled, and positioned for each sail to maximize performance. Getting Started All materials are carefully selected by our sail designers to Getting started is easy and Sailrite’s expert staff is available toll best suit your application and only high quality sailcloths and free every working day to answer questions and help guide you laminates from Bainbridge, Challenge, Contender and others who through the ordering and construction process.
    [Show full text]
  • 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.
    [Show full text]
  • 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.
    [Show full text]
  • Further Devels'nent Ofthe Tunny
    FURTHERDEVELS'NENT OF THETUNNY RIG E M H GIFFORDANO C PALNER Gi f ford and P art ners Carlton House Rlngwood Road Hoodl ands SouthamPton S04 2HT UK 360 1, lNTRODUCTION The idea of using a wing sail is not new, indeed the ancient junk rig is essentially a flat plate wing sail. The two essential characteristics are that the sail is stiffened so that ft does not flap in the wind and attached to the mast in an aerodynamically balanced way. These two features give several important advantages over so called 'soft sails' and have resulted in the junk rig being very successful on traditional craft. and modern short handed-cruising yachts. Unfortunately the standard junk rig is not every efficient in an aer odynamic sense, due to the presence of the mast beside the sai 1 and the flat shapewhich results from the numerousstiffening battens. The first of these problems can be overcomeby usi ng a double ski nned sail; effectively two junk sails, one on either side of the mast. This shields the mast from the airflow and improves efficiency, but it still leaves the problem of a flat sail. To obtain the maximumdrive from a sail it must be curved or cambered!, an effect which can produce over 5 more force than from a flat shape. Whilst the per'formanceadvantages of a cambered shape are obvious, the practical way of achieving it are far more elusive. One line of approach is to build the sail from ri gid componentswith articulated joints that allow the camberto be varied Ref 1!.
    [Show full text]
  • East-1946.Pdf
    YACHTING -THE u. s . ONE-DESIGN CLASS IDS ONE-DESIGN class, which is T sponsored by a group of yachtsmen The perm4nent b4ckst.,ywtll keep representing all three clubs at Marble­ head, bids fair to become one of our popu­ the rig in the bo"t while the run­ lar racmg classes. Developed on the boards ning b4ckst4y will be needed in p~liminary plans by Carl Alberg, of only to 4Ssure the jib st4nding Marblehead, who is as80ciated with the well or to t4ke the tug of the ~den office, the general dimensions of the '\ rspinn4ker~ !' "" new boat arc: length over all, 37' 9"; \ length on the water line, 24'; beam, 7'; draft, 5' 4"; displacement is 6450 pounds. \ Her sail area is 378 8quarc feet, of which 262 square feet is in the mainsail and 116 \ square feet in the jib. In addition, there is \ a genoa with an area of. 200 square feet and a parachute spinnaker. \ An interesting feature of the new boat is a light weight, portable cabin top · \ which is made in two sections and may be \ carried in bad weather or for overnight I cruising. The cockpit, with the cabin top · removed, runs all the way forward to the . \ mast to facilitate light sail handling with­ Fastenings will_be made of bronze, the out the necessity of going on deck. The keel will be of lead and her hollow spars helmsman is 80 placed that he will get no will be spruce. Fittings and rigging will be interference from his crew, yet he will be by Merriman Brothers.
    [Show full text]
  • Sail Power and Performance
    the area of Ihe so-called "fore-triangle"), the overlapping part of headsail does not contribute to the driving force. This im­ plies that it does pay to have o large genoa only if the area of the fore-triangle (or 85 per cent of this area) is taken as the rated sail area. In other words, when compared on the basis of driving force produced per given area (to be paid for), theoverlapping genoas carried by racing yachts are not cost-effective although they are rating- effective in term of measurement rules (Ref. 1). In this respect, the rating rules have a more profound effect on the plan- form of sails thon aerodynamic require­ ments, or the wind in all its moods. As explicitly demonstrated in Fig. 2, no rig is superior over the whole range of heading angles. There are, however, con­ sistently poor performers such ns the La­ teen No. 3 rig, regardless of the course sailed relative to thewind. When reaching, this version of Lateen rig is inferior to the Lateen No. 1 by as rnuch as almost 50 per cent. To the surprise of many readers, perhaps, there are more efficient rigs than the Berntudan such as, for example. La­ teen No. 1 or Guuter, and this includes windward courses, where the Bermudon rig is widely believed to be outstanding. With the above data now available, it's possible to answer the practical question: how fast will a given hull sail on different headings when driven by eoch of these rigs? Results of a preliminary speed predic­ tion programme are given in Fig.
    [Show full text]
  • STANDARD SAIL and EQUIPMENT SPECIFICATIONS (Updated October, 2016)
    STANDARD SAIL AND EQUIPMENT SPECIFICATIONS (Updated October, 2016) 1. Headsails, distinctions between jibs and spinnakers A. A headsail is defined as a sail in the fore triangle. It can be either a spinnaker, asymmetrical spinnaker or a jib. B. Distinction between spinnakers and jibs. A sail shall not be measured as a spinnaker unless the midgirth is 75% or more of the foot length and the sail is symmetrical about a line joining the head to the center of the foot. No jib may have a midgirth measured between the midpoints of luff and leech more than 50% of the foot length. Headsails with mid-girths, as cut, between 50% and 75% shall be handicapped on an individual basis. C. Asymmetrical spinnakers shall conform to the requirements of these specifications. 2. Definitions of jibs A. A jib is defined as any sail, other than a spinnaker that is to be set in the fore triangle. In any jib the midgirth, measured between the midpoints of the luff and leech shall not exceed 50% of the foot length nor shall the length of any intermediate girth exceed a value similarly proportionate to its distance from the head of the sail. B. A sailboat may use a luff groove device provided that such luff groove device is of constant section throughout its length and is either essentially circular in section or is free to rotate without restraint. C. Jibs may be sheeted from only one point on the sail except in the process of reefing. Thus quadrilateral or similar sails in which the sailcloth does not extend to the cringle at each corner are excluded.
    [Show full text]
  • Experimental Investigation of Asymmetric Spinnaker Aerodynamics Using Pressure and Sail Shape Measurements D
    Experimental Investigation of Asymmetric Spinnaker Aerodynamics Using Pressure and Sail Shape Measurements D. Motta, R.G.J Flay, P.J Richards, D.J Le Pelley, Julien Deparday, Patrick Bot To cite this version: D. Motta, R.G.J Flay, P.J Richards, D.J Le Pelley, Julien Deparday, et al.. Experimental Investi- gation of Asymmetric Spinnaker Aerodynamics Using Pressure and Sail Shape Measurements. Ocean Engineering, Elsevier, 2014, a paraitre. 10.1016/j.oceaneng.2014.07.023. hal-01071557 HAL Id: hal-01071557 https://hal.archives-ouvertes.fr/hal-01071557 Submitted on 8 Oct 2014 HAL is a multi-disciplinary open access L’archive ouverte pluridisciplinaire HAL, est archive for the deposit and dissemination of sci- destinée au dépôt et à la diffusion de documents entific research documents, whether they are pub- scientifiques de niveau recherche, publiés ou non, lished or not. The documents may come from émanant des établissements d’enseignement et de teaching and research institutions in France or recherche français ou étrangers, des laboratoires abroad, or from public or private research centers. publics ou privés. Science Arts & Métiers (SAM) is an open access repository that collects the work of Arts et Métiers ParisTech researchers and makes it freely available over the web where possible. This is an author-deposited version published in: http://sam.ensam.eu Handle ID: .http://hdl.handle.net/10985/8690 To cite this version : D MOTTA, R.G.J. FLAY, P.J. RICHARDS, D.J. LE PELLEY, Julien DEPARDAY, Patrick BOT - Experimental Investigation of Asymmetric Spinnaker Aerodynamics Using Pressure and Sail Shape Measurements - Ocean Engineering p.a paraitre - 2014 Any correspondence concerning this service should be sent to the repository Administrator : [email protected] Experimental Investigation of Asymmetric Spinnaker Aerodynamics Using Pressure and Sail Shape Measurements D.
    [Show full text]
  • THE CRAB Claw EXPLAINED TONV MARCHAJ CONTINUES HIS INVESTIGATION
    Fig. 1. Crab Claw type of sail under trial in •^A one of the developing countries in Africa. THE CRAB ClAW EXPLAINED TONV MARCHAJ CONTINUES HIS INVESTIGATION Francis Bacon (1561-1626) ast month we looked at the mecha­ nism of lift generation by the high schematically in Fig. 3, is so different that I aspect-ratio Bermuda type of sail. it may seem a trifle odd to most sailors. We also considered "separation", a sort of unhealthy' flow which should be avoided Lift generation by slender foils r a sudden decrease In lift and a concur- (Crab Claw sail) ent increase in drag are to be prevented. There are two different mechanisms of A brief remark was made about a low lift generation on delta foils. One type of aspect ratio sail with unusual planform, lift, called the potential lift, is produced in and of other slender foils capable of deve­ theconventionalmannerdescribedinpart loping much larger lift. The Polynesian 2; that is at sufficiently small angles of Crab Claw rig. winglets attached to the incidence, theflowremainsattached to the keel of the American Challenger Star and low pressure (leeward) surface of the foil. Stripes (which won the 1987 America's This is shown in sketch a in Fig. 3; there's Cupseries)andthedelta-wlngof Concorde no separation and streamlines leave the — invented by different people, living in trailing edge smoothly (Ref. 1 and 2). different times, to achieve different objec- ' ives — belong to this category of slender loils. Fig. 2. Computational model of winged- keel of the American 12 Metre Stars and The question to be answered in this part Stripes which won back the America's Cup is why and bow the slender foils produce 5 Fool Extension.
    [Show full text]
  • Rigging Your Hoyt Jib Boom ®
    RIGGING YOUR HOYT JIB BOOM ® Note: Forespar ® does not supply blocks and tackle. The clew plug casting provided has an attachment point (narrow end facing down) for a double block. This block should have a swivel style head. You will need a single block and a single block with a becket for attachment to your deck or rail port and starboard in-line with the clew plugs arc of movement. Be sure there are no obstructions as this will be your jib boom sheet. Wide assortments of blocks are available with deck mounts or with shackle heads for attachment to toe-rails. You will need to decide what style is best suited for your boat. Decide which side of your boat you want the jib boom sheet to lead aft and mount the single block with becket on that side. The single block without the becket mounts on the opposite side. Run the line from the becket block through one of the sheaves on the double block on the clew plug and back through the single block without the becket, then back to the single block with the becket and then aft. On some boats, you may need additional lead blocks for the sheet to lead aft depending on your particular deck layout. The double sheaves in the clew plug are for the line coming off the clew of your jib. This single line should be lead through the clew plug and then forward to a single block attached to the base of the pedestal. There is an attachment point on the backside of the deck pedestal for this block.
    [Show full text]