Multihull Structure Thoughts

Discussion in 'Multihulls' started by oldmulti, May 27, 2019.

  1. SolGato
    Joined: May 2019
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    Location: Kauai

    SolGato Senior Member

    I was talking with Mike of MultiMarine the other day and he was telling me about his custom Concept 40 Catamaran Minette.

    Since we recently discussed the Edel Cat concept, I thought I would post about Minette.

    What’s neat about it is he cold molded it, then adapted Skip Johnson’s arm and socket beam concept to it, making it demountable and trailerable.

    When the boat was completed, he loaded it on trailer and trucked it to Florida where it was assembled and launched and sailed to the Bahamas

    I asked him how the arm and socket beam system has held up after all these years and he said very well, and that it’s still a very competitive boat.

    13B52584-3BD7-4BB5-91CF-BBEC740281AE.jpeg
    CA652D57-C096-4F1D-B4E1-831A39CB7CF9.jpeg
     
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  2. oldmulti
    Joined: May 2019
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    oldmulti Senior Member

    The second part of the JAMADHAR 100 performance cruising catamaran designed by Greg Young. It is 96 foot total length including bow sprit. The actual cat is 88.5 x 44.3 foot with a displacement of 213,000 lbs. The 115 foot carbon fibre mast (weighs 3,900 lbs full rigged) carries a 2,920 square foot mainsail, a 882 square foot staysail, 1,505 square foot genoa and 3,605 square foot Code 0. The length to beam on the hulls is about 10 to 1 at the waterline. The draft is 7.2 foot over the low aspect ratio fin keels. The two 6 cylinder YANMAR turbocharged diesel engines of 315 HP, driving through shaft drives.

    The structure of this cat is a foam glass, Kevlar and carbon fibre epoxy infused structure. The hulls from the interior to the exterior are 2 layers 1156 gsm e-glass warp triaxial 90/±45°, a 40 mm corecell core (A800/A600/P500) or Airex 63 and on the external of the hull 890 gsm kevlar/e-glass hybrid fiber 0/90° with 2 layers of 1156 gsm e-glass warp triaxial 90/±45° and a 290 gsm e-glass plain texture cloth all epoxy resin infused and cooked in an oven. Bulkheads and longitudinals are flat panels are as specified in the designs, the core material used for the entire internal structure is AIREX C70.75 Pl. All the chain plates have been built in composite material and are incorporated to the hull structure with bushings and pivots made in stainless steel 2205 and stiffeners made in carbon fiber.

    The decks specifications are from the exterior towards the interior. Externally 831 gsm a 0/90°, 2 layers 1,156 gsm E-GLASS WARP TRIAXIAL 90/±45°, a 25 mm AIREX c70.75 Pl core and internally 1,156 gsm E-GLASS WARP TRIAXIAL 90/±45° with an 800 g/m2 a ±45° in epoxy resin infused and cooked. The cabin structure from the exterior towards the interior is 1,156 gsm E-GLASS WARP TRIAXIAL 0/±45°, 1,156 gsm E-GLASS WARP TRIAXIAL 90/±45°, a 40 mm AIREX C70.75 Pl core and internally 1,156 gsm E-GLASS WARP TRIAXIAL 90/±45° with a 1,156 gsm E-GLASS WARP TRIAXIAL 0/±45° again in epoxy resin infused and cooked. The forward bow cross beam is of semi-elliptical shape (600x400 mm section and 11000 mm length) and is glass fiber resin infused. Also please understand there is solid inserts in the foam glass shell for hard points like sail tracks, winch points, reinforcing structures and top and bottom flanges of cross beams etc.

    The structure is for a 213,000 lbs catamaran. Greg Young has designed many 60 to 90 foot cats and knows about the structural requirements. Please trust your designer of a 50 foot cat when he says a single layer of 1156 gsm triaxial e-glass in vinylester on the outside skin of a foam glass build. Your 50 foot cat probably displaces 35,000 lbs or 20% of the JAMADHAR 100. There is no need to “add” to the structure for “safety” to smaller designs.

    To give a feel for the size of equipment required look at the primary anchor, it’s a 320 lb CQR anchor with 400 foot of 16mm calibrated link chain going to a MAXWELL 4500 anchor winch and 2 MAXWELL 4000 warping winches at the bow. Or how about the 5800 litres of fuel or the 5800 litres of water carried by the cat. The fluids and anchor gear alone weighs over 25,000 lbs. For those who dream of big boats please understand they come with massive investments of money and time. You need a full time engineer/mechanic on board these vessels to keep them running. Limited jpegs sorry.

    Finally, for those who think money is no object they may be right. Jeff Bezos (Amazon) recently launched his 127 meter (416 foot) $500 million sailing yacht. It was built in a factory up a river from sea. The boat was so big that it required an historic bridge over the river to be disassembled to allow the boat to go down the river. The bridge was then rebuilt. This was cheaper than moving the production factory closer to the sea. Bezos makes more money in an hour than you and I would in a life time.
     

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  3. oldmulti
    Joined: May 2019
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    oldmulti Senior Member

    The Richard Woods design Saylon 20 is the maximum accommodation 20 foot trailer sailer that Richard has designed. This cat is an inshore sailor which Richard calls it a "Sheltered Water" only boat (Category D under Europe's RCD). The Saylon is 20 x 8.2 foot weighs 1500 lbs and displaces 2030 lbs. The rig can be a Hobie 16 or a mainsail of 140 square foot with a jib of 75 square foot. The length to beam of the hulls at the waterline is 10.3 to 1. The hull draft is .9 foot or 3.2 foot with the daggerboards down. The rudders are outboard. The power can be a 5 to 10 HP outboard.

    This cat is about accommodation with some performance. the major difference between Saylon and other 20 foot cats is that there are a center cockpit and an aft double cabin. That helps keep the weight out of the ends, it also makes sail handling easy and separates the living and sleeping areas. The aft cabin contains a double berth and space for portapotti. There are 2 single quarter berths in the hulls partially under the cockpit. The “main cabin” has a galley and some seating and variable headroom with a “drop” floor available when moored. When sailing the headroom is 4.4 foot, when moored the headroom is 6.1 foot with the floor dropped in the main cabin.

    The structure of this cat is plywood and timber. The hull sides are 6 mm ply, the keel plank is 9 mm plywood with 2 layers of 4 mm in the lower bow sections forward. The stringers and chines are full length. There are plywood bulkheads with timber reinforcing. The drop floor has canvas sides. The decks are 6 mm ply and the underwing is 9 mm ply. The cabin structures are 6 mm ply. The exterior surface is covered by 200 gsm glass in epoxy. There is some 400 gsm biax for strengthening. This boat only requires 3000 screws. This cat is a relatively simple build but you will still take 500 to 1000 hours if you are experienced.

    The materials list is as follows: 4mm plywood 3 sheets or 13 sheets (depending on hull planking thickness), 6mm plywood 25 sheets or 13 and 9mm plywood 3 sheets.
    Timber
    11/2in x 1in (finished size 35 x 20mm approx) 150m
    2in x 1in (finished size 45 x20mm approx) 35m
    1in x 1in (finished size 20 x 20mm approx) 50m
    3in x 1in (finished size 70 x 20mm approx) 10m
    4in x 11/2in (finished size 95 x 35mm approx) 3m
    Epoxy approx 40kgs plus fillers as required, 400g biaxial glass 5kgs, 200g glass cloth for sheathing 8kgs (can be 300g, 12kgs). 3000 18mm (3/4in) #6 st steel screws

    Performance of the Saylon is reasonable but EG a Chat 18 will be faster around a course. The Saylon 20 needs dagger boards to get too windward as the upper windage is reasonably large compared to the available sail area. This is a fun cruiser for mum dad and 2 kids. You could spend a week away in reasonable comfort. The jpegs give the idea.
     

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  4. oldmulti
    Joined: May 2019
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    oldmulti Senior Member

    Today, a dream that may become a reality. A power catamaran that is actually an electric “truck”. Elon Musk of Tesla says the Cybertruck will be in production in 2023, as with all Elon’s possible dates it may not happen in 2023 but it will happen. The next concept is to convert Tesla's Cybertruck into a CATAMARAN within minutes has been unveiled in a futuristic concept by a US-based materials scientist, Anthony Diamond of TSWLM Electric Vehicles Inc.

    An accessory kit developed by TSWLM allows you to attach an outrig the a Cybertruck with lowerable pontoons and electric outboard motors. This gives the Cybertruck a speed of 25 mph on the water — or 40 mph if you opt-in for the added hydrofoils. The Cybercat outrig kits are expected to retail for around $22,900–$32,900 and the 'Foiler' version for $35,400–$42,900 (US dollars).

    When the Cybercat and Foiler is not in use, the developers said, its parts are designed to be stored within the Cybertruck and can be installed again 'by a single person in less time than it takes to launch a boat.' 'We believe that with more than 1.3 million Cybertruck reservations, the market potential for Cybercat is immense,' Mr Diamond said.

    There are several stories on the Cybercat and one web source is: Tech: Incredible Cybercat accessory transforms Tesla's Cybertruck into a CATAMARAN within minutes | Daily Mail Online https://www.dailymail.co.uk/sciencetech/article-10494107/Tech-Incredible-Cybercat-accessory-transforms-Teslas-Cybertruck-CATAMARAN-minutes.html

    Sorry about the lack of detail and limited jpegs but this is a fairly new development that has not even been prototyped yet. It will be fun if it works.
     

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  5. Tony.Ellen
    Joined: Nov 2019
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    Location: Sweden

    Tony.Ellen Junior Member

    A very quick post of the missing photo's I knew were floating around in an old drive.

     

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  6. Hell_Bent
    Joined: Sep 2021
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    Location: Vancouver BC, Canada

    Hell_Bent Junior Member

    I would buy one hands down. I'm in the market for a boat at the moment and I would snap one of those up in a second. Looks like one of the coolest small production cruising cats of the century, shame it was a commercial failure.
     
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  7. oldmulti
    Joined: May 2019
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    oldmulti Senior Member

    The Richard Woods designed trailable Skoota 20 power catamaran uses a central 25hp Yamaha outboard and features a small central cabin (with double berth and galley) so it can be used as a basic cruising boat. The Skoota 20 is 19.4 x 12.6 foot (foldable to 8 foot for transport on a trailer. This is a true trailer boat) with a weight of 1,000 lbs and a displacement of 1,500 lbs. The length to beam of the hulls is 12.5 to 1. The draft is 0.8 foot. The asymmetric hull shape has 2 functions, the first is to minimise the curve on the inside to minimise wave interaction between the hulls. The second function of the hull shape relates to trailing which requires a high buoyancy section high up on the hull to encourage unfolding when it is launched. The flatter inner hull sides help reduce total towing height. The folding system used on the Skoota 20 has been used for 20 years on some of Richard Woods trailer sailors such as Sango etc. Essentially as the trailer is backed into the water the buoyancy of the hulls lifts them into position. As the boat is retrieved, gravity lowers them. So, no physical effort is required, nature does all the work.

    The outboard power is 5 to 25 HP with speeds up to 15 knots. With one person on board, it will do 15 knots, or 14 knots with three on board. The Skoota hull is a semi-displacement hull, so unsuitable for higher speeds. Fuel consumption is 8 mpg at 10 knots.

    The accommodation in the cuddy is a double berth that converts to seating and a small galley. The headroom is 4.4 foot. A portapotti can be stored in a hull. This is just enough accommodation for a couple to cruise for a week. The Skoota 20 is intended to mainly be an inshore power cruiser with limited coastal capability.

    Not everyone can build complex shapes, but everyone can build in flat panels. So, Skoota’s are built using conventional plywood-stringer-frame construction with all surface’s glass/epoxy sheathed. This build method is still cheap and fast. Because the boat is modular, it can be built in a garage. Building in sections is quick to build each section, thus progress appears to be fast. There is little fairing to do, just smoothing the glass joints. The crossarms are box sections that pivot on 18 mm aluminium pins. The engine fairing is about 600mm fore/aft, 250mm deep and max 100mm wide. As an experiment Richard took it off. The Skoota 20 only got up to about 6 knots before the wake was washing over the engine. Not a good idea! So, an engine fairing is an essential part of the design. The first hull was built 92 hours and the total build depending on skill can be 500 to 1000 hours.

    The build materials for the Skoota 20 structure are: 6mm plywood for bulkheads 2 sheets: hull sides 10 sheets: cuddy lower sides 4 sheets: cuddy sides/roof 3 sheets: beam boxes 1 sheet.
    9mm ply: hull bottoms 1 sheet: hull decks 2 sheets: cockpit/cuddy floor 4 sheets cockpit seats 1 sheet: foredeck 1 sheet: interior 1 sheet
    Total plwood: 6mm ply 20 sheets 9mm ply 10 sheets.
    Timber 1in x 1in 10m: 2in x 1in 100m (used for framing, chines, gunnels etc): 11/2in x 1in 60m (used for hull stringers, deck stringer, framing etc) : 2in x 2in 10m 4in x 1in 5m: 4in x 2in 5m: 6in x 1in 3m.
    25kg epoxy (min): 10kgs 200 gsm glass cloth.

    The jpegs give an idea of the build and cat. This is an excellent small design that led on to the larger Skoota power cat series which has been very successful.
     

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  8. oldmulti
    Joined: May 2019
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    oldmulti Senior Member

    This pacific proa was featured on the ProaFile as a mystery proa. The proa is ASKELLIC designed by Marin and built by Olivier Berton in about 2010. The proa is 29.2 x 18 foot with a displacement of 2,900 lbs. The Balestron rig carries 377 square foot of sail. A balestron rig can rotate and is nearly self balancing which reduces any sheet loads. The free standing rig is mounted on the pod which acts as a righting pod if the proa is caught aback.

    The interior space is limited with 3 single berths, minimal galley and portapotti. The cockpit is comfortable with seating for 4.

    The proa is built with strip plank western red cedar with glass inside and out in epoxy. The float looks as though it has some plywood in the upper sections and deck. The mainhull deck and crossarms look like strip plank cedar with glass.

    I do not know any further detail (and hopefully I attributed the build correctly) or its sailing capability but the only 2 jpegs I have seen of it sailing look as though it could sail well in moderate conditions. Sorry about the limited jpegs.
     

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  9. oldmulti
    Joined: May 2019
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    oldmulti Senior Member

    Jim Pauling Yacht Design is New Zealand based and has an interesting line of monohull and multihulls with one unique feature, they are all designed and built from high molecular weight polyethylene (HMWPE). Plastic sheeting used to make EG skip bins.

    Jim had designed a 6 metre longboat for a customer in Auckland to be built in ply and glass but with the cost of fairing and painting it just wasn't financially feasible to build. This design did however become the base design for his first fabricated (welded) polyethylene boat or what he call NRP (Non Reinforced Plastic). He designed and engineered the boat and helped the company assemble the first boat. During the construction of the first 6 metre, he had been pricing an alloy powercat for a customer in Sydney. He lost the job after the preliminary design based on the cost of a paint job, Jim decided to offer him a polyethylene version. He asked to see the 6 metre and flew in from Sydney. After looking at the 6 metre for a minute he turned to me and said "this is what I want". The 742 powercat design had to meet a 300mm draft requirement in loaded condition and a tight budget. He developed a new way to build the boat to keep it light enough but strong enough to meet this draft requirement.

    The 45 foot sailing featured in the jpegs was being designed for a customer in alloy, however once he saw the 742 powercat being built in polyethylene he changed his mind and wanted it in plastic. The boat is designed for live aboard extended cruising and features many innovative features. The rig is an A-frame with two roller furling headsails for easy short handed sailing and power is twin hydraulic drives off a single motor. There are fore and aft cockpits and the helm is forward in the wheelhouse for unobstructed vision.

    Result of all this as yo can see from the jpegs a range of monohull power boats from 19 foot to 40 foot, a range of power catamarans from 15 foot to 42 foot and a 45 foot sailing catamaran have been designed and have or are being built. The most impressive is Revo 45 jet boat that if powered correctly can do 145 kph, run on rock strewn white water rivers and at one point ran, at speed, 100 foot up a shore line without damage. HMWPE if designed correctly and the plastic panels are “welded” together well is a very tough construction method.

    To quote a magazine review of the 601 (6 metre) mentioned above: “The choice of HMWPE construction was an informed one. Pauling chose it because HMWPE’s very robust, so can withstand the general wear and tear that goes with charter fishing. The boat could equally well be constructed using aluminium, timber or composite panels.

    HMWPE sheets absorb shock, are UV resistant and deaden noise, so the boat is a remarkably smooth, quiet runner – even quieter than a GRP boat – and the hull won’t deteriorate due to sun exposure. Also, as already mentioned, this is a very tough material, so the 601 can be pulled up onto beaches and used in very shallow water where there is the chance of bumping into submerged rocks. A low-speed impact is unlikely to damage the Revo 601’s hull, and minor damage is easily repaired.”

    This needs further investigation. The jpegs give an idea of some of the boats. Jim web site is: https://www.jimpauling-yachtdesign.com/in-design.html#/
     

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  10. oldmulti
    Joined: May 2019
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    oldmulti Senior Member

    Today’s item is about the Revo 601 power boat built with high molecular weight polyethylene (HMWPE) panels, which is a New Zealand first for a commercial charter fishing boat. It is also the first HMWPE boat put into New Zealand survey. The Revo 601 is 19.5 x 5.75 foot with a weight of approximately about 1200 lbs with a 60 HP outboard attached. The minimum draft is 0.7 foot. The hull shape is deep V forward flattening out to a flat dory type stern section. The top speed with the 60 HP outboard is 29.6 knots and a cruise speed of about 12 to 15 knots.

    The structure of the boat is from sheet HMWPE that is “welded” together. Just like an aluminium boat, the hull features two full length bearers and several transverse frames. Because this boat has to meet survey, it also has a full keel. One of the beauties of this material, says boatbuilder Jim Pauling, is that you can control the thickness, adding and subtracting structure where required. He describes the boat as “very strong and robust”. All the hull and transom is fabricated from 12 and 15mm HMWPE, with pressure tested compartments and a Vitex deck. Building is very similar to fabrication with alloy sheet. The welding process is call extrusion welding, all seams are fully welded and tested. HMWPE is a very tough, UV resistant polyethylene which can be extruded in a huge range of colours.

    There are several other boat builders using HMWPE. The jpegs show Arctic Boats 23 and 28 foot models. The 28 foot model is 28 x 10 foot and weighs 7000 lbs with its two 200 HP outboards. The draft is 2 foot. The maximum speed is 40 knots and is classified for offshore work. The hull and “fender tubes” are welded HMWPE. Only the longitudinal bulkheads are connected to the bottom sheet which permits the bottom sheet to flex ever so slightly, thus mitigating shock from the waves and decreasing the noise level greatly. This can only be achieved a material like HMWPE. Arctic HMWPE boats are welded from pre-cut sheets that fit together like a puzzle. No moulds are needed, which makes customizing for different client types an easy task. Making repairs is possible on site: you only need a handheld extrusion welding machine and some welding wire. There is an A23 side view of the hull structure and a bottom view of the A28 hull structure.

    Next is a low powered flat bottom that is built using Plaztuff HMWPE. The 2 jpegs give the idea of how a simple shape can be done.

    Now let’s talk a little about HMWPE. The material comes in many densities, strengths and UV stabilisation. Several manufacturers will provide you with UV stabilised high strength HMWPE in sheet form 1200 x 2400 mm with thicknesses from 5 mm to 25 mm. Plazstuff claim their product is “unique” and provide a comparison of materials. The specific density of Aluminum is 2.70, Steel 7.85, Plaztuff 0.95. (yes, HMWPE can float). For an 8000 Litre water tank these materials would weigh and have wall thickness of the materials. An Aluminum tank using 5mm walls would weigh 1360 lbs. A mild steel tank with 4 mm walls would weigh 3165 lbs. A Plaztuff tank with 12 mm walls would weigh 1150 lbs.

    The following is a generalisation as there are many densities and chemical variations of HMWPE so seek professional advice before doing any actions. The tensile yield and ultimate strength of HMWPE is about half that of reasonably dry oak. The major issue with HMWPE is its only 10 to 12% as stiff (E modulus) as dry oak. If you design the structure accordingly you will end up with a slightly heavier boat than a EG plywood structure but the HUGE advantage, is you do not have to paint or fair the hull. You can use wood type tools to cut and shape the panels but you will need an experienced “welder” to do the final structure.

    The jpegs give the idea.
     

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  11. oldmulti
    Joined: May 2019
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    oldmulti Senior Member

    After the Skoota 20 power cat featured previously Richard Woods designed a power cat that was simpler in concept and required less build time for the average person. It has slightly less accommodation and performance than the Skoota 20 but is more useable for most people who just want to do simple day cruising or overnight camping. The basis for the Skoota 18 was the Chat 18 sailing catamaran but the Skoota 18 has a reinforced rear structure to carry a larger outboard and the hull shape has been slightly modified to handle the extra weight. The Skoota 18 power cat 18.3 x 8.2 foot with a LWL of 17.6 foot. The weight is 700 lbs and has a displacement of 1,500 lbs. The maximum draft with the outboard is 1.2 foot. The outboards can be 10 to 20 HP. This gives an economic cruising speed around 9-10 knots and top speed in the low teens.

    The Skoota 18 is a simple to build and trail power catamaran. It is based on the Chat 18 sailing catamaran but with extra buoyancy aft to take a bigger engine, up to 20hp. A Chat 18 which is very similar to the Skoota 18, the latter has no keels and a slightly different hull shape making it more suitable for a powerboat. The small cuddy offers protection during the day while the boom tent and long cockpit seats mean you can camp on board for a night afloat.

    The boat is built using conventional stitch and glue plywood and epoxy, build time is estimated at 300 hours. For the Skoota 18, the plywood panels are assembled over a light wooden frames and bulkheads with EG longitudinal deck stringers notched into the frames. The panels are epoxy glued to the framing. Long panels are joined by butt blocks. The smaller Skootas are built with the option of all surface’s glass/epoxy sheathed. Because the boats are modular much can be built in an ordinary garage (lengthened as necessary to build the hulls). There is little fairing to do, just smoothing the glass joints. The basic materials list is:

    6mm ply 20 sheets for hull sides, cabin, bulkheads and parts of the beams.
    9mm ply 4 sheets for the hull bottoms and underwing.
    Timber
    2in x 1in 50 mtr; 3in x 1in 2 mtr; 2in x 2in 5 mtr.
    1.5in x 1in 50 mtr (can be 3in x 1in ripped in half)
    Beams 4in x 2in x 2.5 mtr (5 off)
    glass tape 150m 100mm (4in) wide
    Sheathing (optional) 60sqm 200g/sqm (4oz)
    epoxy 40kgs (polyurethane glue optional on deck stringers etc)
    screws 1000 18mm (3/4in) x no6 200 25mm (1in) x no6 st steel cs
    paint, filler etc as required

    Some limited jpegs of the design concept below.
     

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  12. oldmulti
    Joined: May 2019
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    oldmulti Senior Member

    The following proa is of interest mainly because of one feature, it is a 38 foot boat that weight is claimed to be 785 lbs. The “Vanille framboise” proa is 38 x 13.4 foot and weighs 785 lbs. The float is 19.5 foot long. The free standing balestron rig carries 260 square foot of sail area. The draft varies between 0.7 foot and 2.5 foot with its kickup rudders. The outboard is 2.5 HP or use a long oar for tight manovering.

    The accommodation pod contains 2 double berths, a small galley and table. There is storage space and a portapotti. There are solar panels and a battery.

    The mast and boom are carbon fibre structures of small dimensions to carry the small sail area. The cross beams are carbon fibre pultrusion’s that are glassed together in a box shape to form the beams. The beams can slide into the main hull to allow road transport if required. The remainder of the hulls and cabin structure are foam carbon fibre with some glass. This is a very light build with a low sail area but appears to sail well in light to moderate conditions.

    A youtube is available at:

    The jpegs give the idea of this interesting proa.
     

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  13. Hell_Bent
    Joined: Sep 2021
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    Location: Vancouver BC, Canada

    Hell_Bent Junior Member

    Interesting is one way to put it. I get stripping out everything you can to save weight, but I probably would have at least sealed off the ends of the beams, as you can see right through them to the interior in one part of the video. All proas are a work in progress though, and it's nice to see another one sailing.
     
  14. oldmulti
    Joined: May 2019
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    oldmulti Senior Member

    The Saliant 50 (formerly TAG 50) is a high performance cruising cat designed by Greg Young of New Zealand. The Saliant 50 is 50.8 x 28 foot with a weight of 20,100 lbs and a displacement of 24,250 lbs. The 72 foot fixed or rotating carbon mast carries a mainsail of 1,162 square foot, a self tacking jib of 505 square foot, a gennaker of 2,690 square foot and a spinnaker of 1,890 square foot. The length to beam on the hulls is about 10.2 to 1. The sail version has a draft of 8.7 foot over the daggerboards with underslung spade rudders that draw 5 foot. The underwing clearance is 3.2 foot.

    Saliant Yachts in USA brought the TAG 50 moulds after St Francis yacht had business problems and developed their own build approach. The TAG 50 moulds were extensive as indicated by the TAG 50 build PDF. The first cat out of the Saliant owned moulds was configured as a power boat with outboards. But the second is a sailing cat with a super yacht size owners’ cabin, full beam cockpit/saloon living areas, 2 private (owners hull style) guest cabins. The central cabin has a massive galley and seating connected to seating and table in the cockpit with dedicated outboard sailing cockpits.

    The build of the cat is a carbon fibre / resin composite vessel, manufactured by Vacuum Infusion that combines maximum strength with minimum weight. The build jpeg of the bridge deck resin infusion gives the idea of the work involved in just 1 component.

    The jpegs give the idea. The 37 page PDF is from the TAG 50 build report. The second PDF is the TAG 50 brochure.
     

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    Last edited: Feb 27, 2022

  15. oldmulti
    Joined: May 2019
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    oldmulti Senior Member

    Kaos XE54 offshore cruiser from Salient Yachts is confusing. It is claimed to be built from the recently purchased moulds of the Scape 51 catamaran that were extended. On the web site for Saliant Yachts Kaos XE54 shows jpegs of a home built Quest 50 catamaran as an example of what may be possible with the Kaos XE54. Result I will give you the initial specifications for the Kaos then the numbers for the Scape 51 on which it is based.

    The Kaos XE54 is 54 x 28 foot that displaces 22,400 lbs. No sail area or other details are available. The Scape 51 provides the moulds with an extension to the bow to make it a Kaos XE54. The Scape 51 is 51.2 x 26 foot with a displacement of 16,800 lbs and a sail area of 1,575 square foot. The draft of the Scape 51 is 3.5 foot over the rudders and 7.2 foot over the daggerboards. The home built Quest 50 is very similar to the Scape 51 in dimensions. The Quest 50 took 4 years to build with some assistance and an enthusiastic partner.

    Salient Yachts modified the Scape 51 moulds added wave piercing bows and modernized cabins, bridge deck and roof. The internal areas of the galley and saloon areas were also modified.

    The structure was originally built in epoxy E-Glass composite materials to meet Lloyds classification rules.

    The original Scape 51 performance was very good. Du Toit Yacht Design designed the original Scape 51 and has a very good history of high performance catamarans. The Scape 51 could sail in 25 knots winds upwind at 14 knots and hitting high twenties under spinnaker (28 knots). This is a fast cat that considers 12 to 15 knots as reasonable cruising speeds. I cannot comment on the modified hull shape but if the design modifications were done by Du Toit Yacht Design, I would be confident of its performance.

    The accommodation is unknown but I have included the Quest 50 and Scape 51 accommodation plans to give an idea.

    The jpegs run Kaos XE54 then Scape 51 and finally the Quest 50.
     

    Attached Files:

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