Multihull Structure Thoughts

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

  1. kdifzero
    Joined: Aug 2021
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    kdifzero Junior Member

    The only other video on that channel shows a completed catamaran, but I dont think its a Pelin Snowbird.
    Anyone know what it is?
     

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  2. oldmulti
    Joined: May 2019
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    oldmulti Senior Member

    The Lidgard designed Lidgard 45 is a bridge deck performance cruising catamaran that is intended for serious cruising. The cat is 45.3 x 27.2 foot with a weight of 17,360 lbs. Payload capacity is about 3,500 lbs for a displacement of 20,900 lbs. The 60 foot aluminum mast with a fractional rig has a sail area of mainsail is 900 square foot and the self tacking roller furling jib is 337 square foot. The length to beam is 11.8 to 1. The draft is 7 foot over the daggerboards. You can have optional fixed low aspect ratio keels that draw 4.3 foot. The underwing clearance is 3.3 foot.

    The accommodation is 1 double berth cabin and a large bathroom in one hull and 2 double berth cabins and the galley in the other hull. The main cabin has a large seating area, entertainment area and navigation station. The cockpit is accessed through large glass doors.

    The Lidgard 45 is basically a wider beam extension of the Lidgard 39/42/43 performance cruising catamaran which was the basis of the Fusion 40 kit catamaran. The hull shapes on all these vessels are based on the same hull. This allows the structural design to be very similar in all the designs.

    This 45 ft sailing catamaran was designed to be built as a pre-cut epoxy composite kitset. The kitset is available to purchase containing all the composite materials required to construct this vessel. A very comprehensive set of scaled working drawings is supplied by us with a kitset purchase direct from the kitset manufacturer.

    There are two versions for this particular design the difference being that one design package is supplied inclusive with the purchase of a pre cut construction package from ATL Composites (Contact us for kitset details and we will put you direct contact with ATL for pricing the complete or partially complete kit). Or alternatively Lidgard will supply the 45 design as a package that allows a builder to custom build the vessel in a conventional manner. The custom one off construction is from epoxy resin system, stitched glass, foam & balsa cored composites for both shells and internals. Full size cut files are supplied for both hull and deck shell building frames. Drawings are supplied in the form of computer generated scaled cad drawings supplied on a flash drive as Hi-Res pdf files that can be plotted/printed on B1 size media to maintain the page scales or any other page size desired and also viewed on computer.

    Performance of Lidgard cats in the 40 foot range are considered good with several winning local races in Australia on handicap. Peak speeds of 20 knots have been seen with 8 to 10 knot averages possible in the right conditions. The Bruce Number is about 1.2 depending on the sail options used.

    The jpegs give the idea. A good fast cruiser.
     

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  3. oldmulti
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    oldmulti Senior Member

    Lidgard 45 part 2 build.
     

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  4. oldmulti
    Joined: May 2019
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    oldmulti Senior Member

    Flying Nikka is a very high performance 60 foot monohull that the designer, Mark Mills, says in under 9 knots of true wind speed (TWS) will only be slightly faster than a T52 monohull racer. T52’s are very fast in light winds. OK. Over 9 knots TWS Flying Nikka lives up to its name. In 30 seconds Flying Nikka is doing 20 knots of boat speed, at 25 degrees apparent, in 11 knots of TWS. Why are multihulls under threat from monohulls? This boat gives an example.

    Flying Nikka is a foiling monohull of 60 x 15 foot (claimed to be 19.5 foot) over the hull but 36 foot over the foils when fully deployed. The foils are like the AC 75’s that raced in the last Americas Cup. The displacement is 15,700 lbs. The 75 foot mast carries a sail area is up to 6,060 square foot. The North sails jpeg gives the options. The draft is 14.8 foot over the central keel and foils when fully down. The foils are carbon fibre with titanium rams to control their lateral angle. The main foils have flaps on them that are manually controlled with computer AI (artificial intelligence) backup. As the crew sail the yacht more, the more the AI will learn and then more of the control will be transitioning to the AI computer software as the software will be able to react faster to sea variations etc.

    Flying Nikka is a complex, innovative, pure speed machine. A technological and engineering marvel conceived by its Italian owner Roberto Lacorte as: “The dream is to win the Med mid-distance races, like the Giraglia, in real time. Then to have something to compare to a supermaxi like he 100 foot Comanche yet be faster and more fun,” Flying Nikka pushes the boundaries of displacement sailing and foiling. So, we have a 60 foot offshore foiler designed to race boat for boat with the fastest 100 foot monohull racer in the world. Interesting.

    So, during the workup trails what sort of performance did Flying Nikka have. From a Yachting World test “Our simulated race involved a five mile leg to the windward mark. Great stretches of Elba island’s east coast became a distant blur as Flying Nikka maintained stable speeds in the low 20s and at one stage clocked 26 knots at 21° apparent in 14 knots!” and “Then came something I really wasn’t expecting: a tack. My surprise turned to panic as I gripped to hold on, then to amazement at the speed with which the boat turned, and finally to amusement at the G-forces I’d just experienced.” “If I was expecting warp speeds on the off/downwind leg, it soon became apparent that Nikka lacked the extra grunt of a larger headsail in these fluky conditions. Yet even training with their smaller J2 we hit the high 20s – still at 25-30° apparent, but at 120° true as opposed to 50° true upwind – but there were many more landings and longer struggles to lift off again.” And finally, Flying Nikka’s top speed to date is 37 knots in 23 knots of TWS, but that was before initial aeration issues in the wing arm junctions were sorted out. The team thinks over 40 knots is possible, but Mark Mills cautions that soon after that figure they’ll then run into foil cavitation issues.

    The construction is all carbon fibre foam epoxy with ring frames and stringers. The hydraulics are really impressive and driven by a 110 HP Yanmar engine that is always running. At any point on the foils, the foil structure is capable of supporting the 7 ton plus loads placed on them. There is no internal furniture or berths as “the boat is so fast it will complete most races in a day”. Also, this is a very noisy boat with the engine running continuously to control the constantly adjusting foils. The boat also hits wave tops, does take off and landings, has 60 knot apparent winds and the foil humming etc adds to the sound effects.

    This is the first trials of this style of coastal racing offshore boat that has proven to be successful. The owner had it built in 30,000 hours by King Marine on time and under budget. It cost the same as a 75 foot mini maxi. If the 60 foot Flying Nikka can match or beat the 100 foot Commanche around a course this will a “cheap boat”.

    The jpegs will give the idea. Buy the October 22 copy of Yachting World for more detail.
     

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    Last edited: Sep 11, 2022
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  5. oldmulti
    Joined: May 2019
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    oldmulti Senior Member

    This is a little reminder to all about what happens to well built boats that have had a lack of maintenance, modifications or just have been driven hard over a period of time. The first jpegs give you an idea of how hard an enthusiastic owner can sail a boat. The following jpegs are not of that boat but you can get an idea of what can happen to some boats.

    The next 2 jpegs are of a production outboard rudder that broke when sailing hard. This is followed by 4 jpegs of a production underslung rudder that touched bottom at speed. I could show you more broken rudders but you get the idea. Either a new foil or a lot of sanding to form a 1 in 12 angle on the remaining glass shell on each half, carbon fibre cloth, epoxy, filling and fairing and a good as new rudder. The same applies to the broken daggerboards that’s if you can recover the broken bottom half.

    Next jpegs are of the broken crossbeams. Farriers have manuals on how to detect and repair crossbeams that have structural problems. Most of the problems come about due to hard use, nudging a pier or when trailering hitting things etc. But if the issue is not addressed when first noticed then disaster can happen as indicated in the jpegs. The factory manufacturing process is good and is strong enough for normal sailing its just not all skippers treat their tris with the respect they deserve.

    Next are practical examples of what needs to be done when looking after a boat, yes you have to sand the bottom, repaint, antifoul, clean the interior etc. The issues related to outboards and electrics are endless. Either keep your boat simple or routinely inspect and maintain all mechanical and electrical systems. Your life will be simpler and in the long run cheaper. As for the rig and sails, it depends on you style of sailing. If you race, then life can be expensive. If you cruise an upgrade of some variety every 5 years or so may be required.

    But when you get bored you can either sell your boat or do as in the last jpeg, modify it. Under this red boat with a white deck is a 32 foot Farrier that has been modified with bigger fuller ended floats with attached T foil rudders, a fuller longer stern, hiking racks, C section main foils and a smaller section mast. The boat is called “Jailbreak”. A whole lot of extra work but I am sure it sails faster than a standard F31.

    The joy of boat ownership, at least with Farriers you can park it at home, saving yourself marina fees. Also, travelling to windward at 60 miles per hour behind a tow car is easy to get to new locations.
     

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  6. oldmulti
    Joined: May 2019
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    oldmulti Senior Member

    The Eagle 24 is seaworthy enough for coastal passage making and offshore trips in good weather, EG across the English Channel or from Florida to the Bahamas. However, remember as with all small boats, it is the crew that will fail before the boat. So, Richard Woods the designer suggests sailing no more than 70 miles or so non stop, nor cruising overnight with more than 2 adults and 2 children on board. The Eagle 24 is a simple to build plywood, flat bottomed cat for fast cruising.

    The Eagle 24 is 24 x 14.5 foot and weight of 1450 lbs with a displacement 2800 lbs. The mast is 160 x 110 mm and 31 foot high, with 380 square foot of sail. The hull length to beam is 10 to 1. The draft varies from 0.8 foot to about 5 foot over the daggerboards. The rudders are kickup. Outboard power between 5 and 10 HP.

    The Eagle 24 design put more emphasis on interior space than the Strider Shadow series, while still keeping a simple build. Accordingly, it has more freeboard and a longer cabin than the earlier designs, resulting in 5.5 foot headroom and bunks over 2.5 foot wide with sitting headroom. Hulls 3.5 foot wide. There are 4 single berths and room for a small galley and some seating.

    Hull and decks 6 mm plywood with 200 gsm biax glass outside with 50 x 18 mm framing on 6 mm plywood bulkheads and stringers. One builder did 400 gsm double bias on the bottom and 100mm wide 400 gram double bias tape along the chines. Then he did 200 gsm cloth across the hulls in meter wide strips, then the peel ply. Underwing stringers were glassed with 400 gsm biaxial cloth onto each of the longitudinal stringers.

    The fore and aft beams are 150 mm aluminium tubes. The main beam is a wooden version of either plan shown below. The original Strider type of beam or the “deep” beam in the PDF. It depends on how you intend to use the cat. Also, if you cannot get aluminium tubes all beams could be timber as in the Strider type design. The jpegs feature an all wood crossbeam build. Richard can provide many options to suit your circumstances. The basic materials list is shown below.

    Basic Materials List
    37 sheets 6mm plywood, 5 sheets 9mm plywood, All plywood to be best quality Marine grade Gaboon/okoume ply. Ply sheet sizes are 8' x 4', 2440x1220
    2in x 1in 200m, 11/2in x 1in 120m, 1in x 1in 50m, All timber to be at least "Joinery Quality". Unless noted all timber is softwood, eg Douglas Fir, Sitka Spruce, Yellow Cedar.
    45kgs min epoxy, 1kg wood flour or similar filler
    20kgs min 200g glass cloth (biaxial +/-45deg recommended for joints)
    2000 stainless steel countersunk screws 3/4in x 6, filler/paint as required
    Epoxy glue is recommended for all glue joints as it is gap filling and the strongest and most watertight glue
    List excludes errors and waste

    This Eagle 24 sails well according to owners. It can do 8 – 10 knot averages in day sailing with the right conditions and peak at over 18 knots. A very good fast basic cruiser that can be disassembled and taken home for winter refits etc. The jpegs give the idea. The pdf is the plans of the deep mast beam used for this size of cat.
     

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  7. ALL AT SEA
    Joined: Nov 2013
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    ALL AT SEA Junior Member

    **Nice read - as are all your posts, but Jailbreak (as far as I know) isn't modified, but is an F32SR, one of 4 than I can think of (1 Netherlands/ 1 USA/ 2 Aus). They'd be the fastest of the F-boats, but I don't think they ever lived up to expectations, with lower tech Graingers beating them on the water. **
     
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  8. oldmulti
    Joined: May 2019
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    oldmulti Senior Member

    Ocean Renegade built a 45 foot cat before they produced the previously featured ORC R5. The 45 foot cat is actually a Schoinning Arrow 1360 with round bilge hulls, not flat panel hull bottom as offered in the kit version. The Arrow 1360 is 44.6 x 24.3 foot with a weight of 15,400 lbs and a displacement of 19,900 lbs. The 58 foot mast carries 754 square foot mainsail and a 365 square foot self tacking jib. The length to beam on the hulls is 14 to 1. The draft over the hull is 1.6 foot, 3 foot over the rudders and 6.5 foot over the daggerboards. The underwing clearance is 2.7 foot. The recommended engines is 2 x 21-29hp Diesels.

    The optional electrical motive power in the South African build was 2 x Oceanvolt AX-10 which provide a total Electric Power of 20 KW. They provide power to shaft drives and (2) Gori 3 Blade propellers. The auxiliary generator is a Fischer Panda AGT-DC 10000-48volt PMS (10KW). There are Lithium Iron batteries.

    The accommodation is 2 double berth cabins with toilet in one hull and a repeat in the other hull. An optional “owners” cabin can occupy the other full hull with one double berth and a full ensuite bathroom. The bridgedeck cabin has a dinette, galley, entertainment area and avigation station. The large cockpit has a large entrance to the main cabin area.

    Schoinning designs are generally about high performance cruising. According to one owner the Arrow 1360 design fulfills that requirement. “The Schionnings and I was able to achieve my goals with the Arrow 1360. This is easily proved with a test sail in right conditions. Close to wind speed in most conditions from 10 knots true (for example, we routinely do 8.5 to 9 knots in 10-11 knots true). No hobby horsing and very stable in rough conditions. The stability index is very good, making Duet a safe, fast and comfortable cruising platform.” Schoinning claim the design will tack through 90 degrees at a speed of 8 – 10 knots while reaching at 10 - 13 knots comfortably with Main and No. 1 in 15 knots of wind.

    The construction material is epoxy, 80 Kg Corecell infusion with biax and triax cloths. Extensive carbon fibre reinforcing layups are used in bulkheads and spars. The whole boat shell was put in a plastic bag and cooked for 22 hours at 60 to 65 degrees centigrade. There were multiple sensors throughout the bag to ensure even heating during the process.

    The jpegs give the idea of the South African build.. This is a well built boat that would carry a family across an ocean. Good job. Several versions of this design have been built globally. The majority of the jpegs are of the 45 but some are of a GForce 15 built around the same time.
     

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  9. oldmulti
    Joined: May 2019
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    oldmulti Senior Member

    Arrow 1360 part 2 of build.
     

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  10. oldmulti
    Joined: May 2019
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    oldmulti Senior Member

    A short one on development of foilers. When the America Cup turned multihull in 2010, many of us were happy, then NZ decided to play a different game attaching foils to 72 foot cats which changed yachting for ever. So, lets look at the development path. Initially the AC 33 Swiss Alinghi 5 and 90 foot Oracle tri where big and very expensive. There were proposals to compete in cheaper vessels for the next series. A proposal for an AC 45 catamaran (non foiling) (44.1 x 22.6 foot, 3000 lbs weight, 70 foot mast, 1,430 basic sail area) was suggested but eventually a 72 foot cat was settled on. NZ decided they could not outspend USA so they went for new technology, foiling. NZ won. The 72 were 72 x 42 foot with a weight 12,800 lbs. The 130 foot multi element wing mast rigs had 2800 square foot of basic sail area and up to 6280 square foot of total sail area. These cats could top out at 44 knots.

    Again, cost became a limiting factor so after many suggested variations, the foiling AC 50 cats became the racer of choice. The AC 50 were 50 x 27.8 foot with a weight of 5,260 lbs. The 78 foot multi element wing mast rig carries from 1,240 to 1,390 square foot of sail area depending on the jib size carried. These cats could sail at up to 48 knots before cavitation started to happen on the foils.

    The AC started on the foiling monohull path with Larry Ellison of Oracle and Russell Coutts suggesting a high performance racing circuit for catamarans called SailGP. The SailGP 50 cats were basically the same dimensions of the AC 50 cats but were refined in all areas to make them faster. EG the same hull moulds were used for the majority of the hull but the bow and sterns were reshaped. Also the bows were “bolt on” to allow the 50 foot cats to be transportable in containers. The wing masts became 2 part instead of multi element which lowers cost and simplifies there build. Also again they can be broken down for container transport. The foils were reshaped and reprofiled to allow higher top speeds These cats cat top out at 54 knots before cavitation sets in. The final major change was limiting the crew size to 5 people and team size to 18 people. All this was to minimise costs.

    All this development happened in 10 years from non foiling multihulls that could have a maximum speed of 40 knots to foiling cats that were half the size, carried half the crew and could sail controllably at up to 54 knots. All of these designs can sail at up to 3 times wind speed in lighter airs. During this time the crews learnt how to tack foiling cats whilst on foils. The foiling cats were so fast that they were always going “upwind” even when they were on reaching or a run course.

    These multihulls have inspired the monohull guys to develop foiling machine that have resulted in 30 knot plus global ocean racers. The future will be interesting.
     

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  11. Doug Halsey
    Joined: Feb 2007
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    Doug Halsey Senior Member

    You're forgetting the comeback of the century!

    USA won the 2013 America's Cup.
     
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  12. oldmulti
    Joined: May 2019
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    oldmulti Senior Member

    Mair 47 cat designed as an aluminum kit cat from Global Marine from Western Australia. The cat is 47 x 24 foot, built weight is 19,400 lbs with an average displacement is 22,400 lbs. The sloop rig mainsail is 775 square foot, 421 square foot jib and 1290 square foot genoa. The aluminum tube mast is 56 foot off the deck. The length to beam is 8.7:1. The cat has low aspect ratio keels and skeg mounted rudders. Underwing clearance is 3.2 foot. The forward freeboard is 6.1 foot. Its basic engines are two 50 horsepower diesels.
    The structure is all aluminum. All plate is 5083 and 6082 extruded sections. The hull bottoms are 5 mm, hull sides are 4 mm, decks 4 mm, cabin superstructure 4 mm, main cabin roof 3 mm. Hull frames are spaced every 700 mm. The hulls and decks have fore aft stringers. Internal fit out is your choice but probably plywood and timber. The real advantage of building in aluminum is the builder will have the skill to do their own aluminum mast, integrated chain plates etc which can be a real cost saving. The other advantage, if you can build the external shell smoothly enough, is you don’t have to paint the cat ever. Unfortunately, most people want the cat to reflect a colourful aspect of their lives and insist on painting a cat. Goodbye to $40,000 and a lot of hard work. The only downside of aluminum is corrosion control.

    This aluminum “kit” to build the boat is delivered to your location as a 30 x 7.6 foot box that weighs 15,900 lbs. All you have to do is weld the pre-cut labelled parts together in the right sequence, fair the resulting structure, paint it, fit out the internal furniture, run the electric, do the mechanicals, fit out the boat handling gear, do the rig and after 10,000 hours of work and you are sailing. This is a solid cruising cat that will go anywhere.

    The jpegs give the idea with the PDF being a study plan.
     

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  13. oldmulti
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    oldmulti Senior Member

    The final Global Marine design is an aluminum charter power catamaran, the Hamo 570. The Hamo 570 is 55.8 x 25 foot with a weight of 47,600 lbs and a displacement of 65,000 lbs. The hull length to beam on the multi chine hulls is 10 to 1. The engines are Twin Volvo IPS450 (370 hp) with a total installed power 740 hp. Top speed is 21 Knots, cruise speed is 15 Knots. Fuel capacity is 2 x 1000 litre tanks. The underwing clearance is 3 foot.

    The multichine hull shape is for ease of building but it also has one other feature fairly wide long keels. The keels help directional stability but also have another advantage of adding buoyancy (and sometimes tank space). This hull shape can be surprisingly efficient if well done. As a testament to the ability of these hulls they in testing “achieved a genuine 19 knots at 2200 RPM in 2 metre rough seas. With some fine tuning the hull looks good for 21 knots with these engines.”

    This flexible vessel has seating for 60+ passengers plus disabled access and facilities. Below decks features two double cabins rest rooms and a galley to cater for guests. Initially designed as a charter catamaran, this kit set is also very well suited to coastal cruising or as an economical passage maker.

    The construction of this cat comes from an aluminum kitset with 5 mm hull bottom plates, 4 mm aluminum side plates, 4 mm deck and superstructure plates. The frames are nominally spaced at 700 mm centre lines and there are fore and aft stringers at 300 to 400 mm centerlines. If you are a good aluminum welder a kitset like this could build you a cat shell this size quickly but as I said yesterday the finishing off of the interior and exterior would take the majority of the build time. You would not believe how long it takes to do the electric’s, plumbing and mechanical installations on boats this size. If you are smart you plan all this out before you start building the shell as you may find installing plumbing and wiring lines before you EG do side plating may speed things up enormously.

    This design would be very suitable for a coastal power cruiser. The jpegs give the idea.
     

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  14. oldmulti
    Joined: May 2019
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    oldmulti Senior Member

    Jessica Rabbit is a 40 foot performance cruising trimaran designed in 2009-10 by Benoit Cabaret, John Level and Martin Fisher. If any of those names seem familiar think Flying Fantom, Groupama 4 the 60' Orma, AC-45, Fujifilm, etc. Jessica Rabbit was built by Marine Performance Noumea in 2012, New Caledonia. After some ownership changes and name changes to Jessie then in 2017 changed to Jess. The tri is still a fast cruiser that occasional lead its class in things like the Route De Rum in 2019. OK.

    Jess is 40 x 39.5 foot (LOA 45.5 over the bowspirit) with a displacement of 8,300 lbs. The rotating carbon wing mast is 60 foot high with an upwind sail area of 1,400 square foot and a downwind sail are of 1,830 square foot. The Mainsail 753 square foot, Gennaker: 1,075 square foot, Solent: 540 square foot, Code 0: 860 square foot, Staysail: 330 square foot, Storm jib 194 square foot. The draft is from 5 foot to 11.5 foot. There are 3 rudders with T foils on them, 2 lifting C section foils in the floats and daggerboard in the main hull. The engine is Lombardini 27CV engine with a folding two-bladed propeller.

    The accommodation is a double berth, 2 single berths in the main cabin with seating, a galley and navigation area. The cockpit is set up for racing as is the majority of the rest of the boat but it has several roller furling headsails.

    So what does all this achieve? Martin Smith wrote “so far our top speed has been 33.1 knots in about 19 knots of wind, two sail reaching on flat water. We have rather regular trade winds here in Noumea and while broad reaching we achieve regularly 30+ knots of boat speed.” And “We are still "discovering" the boat, but we are getting better at sailing her. Jessica Rabbit has - for the size of the boat - relatively large foils and she has T-rudders. This combination of big foils with T-rudders stabilizes the boat very nicely. So far we never have had any critical nose dive situation or any kind of pitch instability. We sailed the boat once with normal rudders in about the same conditions as on the video. The difference was quite dramatic. Broad reaching the boat was much less stable. Average speed was about 2 knots lower and top speed more than 3 knots lower.

    Upwind the boat is pretty amazing for a 40-footer. Up to about 16 knots of wind we are doing 14 to 15 knots of boat speed, which is what we expected. But in 18 to 20 knots of wind the boat suddenly steps on her foils while sailing upwind and boat speed increases instantaneously from about 14.5 kts to 17.5 kts. This was achieved with a true wind angle of about 44 to 45 degrees.”


    This was early in its work up before it was refined by new skippers, the result now is “The boat is capable of doing 17 to 18 knots upwind, and when reaching she regularly exceeds 30 knots with a maximum speed (for now) of 35.3 knots. The foils have a very moderate "S" shape, and they are not designed to make the boat fly completely. Unlike the old ORMA 60, the boat is equipped with “T” rudders which stabilize the trim of the boat. We also did some tests with standard rudders, but with T-shaped rudders the boat is much more stable and safe and it goes reaching and downwind around 3 to 5 knots faster!”

    The construction in the hulls is epoxy-carbon sandwich. The mast is a pivoting carbon wing and the boom is carbon.

    So here you have a fast cruiser with accommodation that does 18 knots upwind and can reach 35 knots reaching. I need to redefine may idea of a 40 foot fast cruiser. The jpegs give the idea.
     

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  15. oldmulti
    Joined: May 2019
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    oldmulti Senior Member

    There must be a large supply of very rich people in this world judging by the amount of very large designs with luxury accommodation available for people with at least $10 million available. The Dragonship 25 is the latest designed by Naval Architect Gillian Grey with interior design by the builders Pi Superyachts Ltd. The Dragonship 25 comes in 3 forms, a power trimaran model, a conventional sail rigged motor sailor trimaran and a reefable wingsail sail assisted model. We will focus on the reefable Autosail soft wing system trimaran.

    The Dragonship 25 is 87 x 50.8 foot with a displacement of about 100 tons (224,000 lbs). The 92 foot carbon mast has an Autosail soft wing system with about 3300 square foot of sail area. But the real truth of this design is told by the length to beam on the main hull is 5.8 to 1 and the length to beam on the floats is 12 to 1. The draft is 4 foot over the hull, no mention of any foils or rudders but I would imagine 6 foot minimum draft. Engines - LMC V26 Electric Motors Generators - 9kWh Solar Panels plus Hydrogen fuel cell Bimini with 4.5kWh solar panels Batteries - 200KWh Solid State Lithium. Tankage includes NH2 - Hydrogen tanks - 5000 litres.

    The Autosail* soft-wing sail system is claimed to be able to propel the yacht up to and beyond 22 knots with 2 x electric propulsion motors which convert to generators when sailing. The two Hydrogen fuel cell generators to provide all the comforts you would expect to enjoy at home. The Autosail soft wing sail system was invented 30 years ago by Jack MannersSpencer. He used a wing shape similar to the WWII Spitfire fighter, a greater lift and lower drag can be provided to a yacht if the wing was placed vertically.

    The accommodation is anything you want. In this version there are 7 cabins with at least 2 single or a double berth with attached toilets in the hulls. Your crew has its own seating arrangements beside the very large ships galley in the lower main hull. The maindeck has 2 more double berth master cabins with ensuites and forward saloon seating for dining and entertainment. There also is an internal navigation and helming station forward. Aft is an exercise room with gym equipment. Aft is a very large cockpit. The flybridge is where all sail handling is done, but the majority of controls are done by powered winches. This is the first boat I know where you could hide away from others for days.

    The hull and superstructure can be built in GRP or Aluminium. The mast, boom and battens are Carbon fibre Autosail soft wing system.

    General thoughts. When you design a tri this size that has a very fat main hull and permentaly immersed floats you may as well design a catamaran which will provide as much room in an easier to build structure. The cat will have thinner hulls and will probably sail faster under most conditions. The amount of equipment and rig etc will be about the same. The only advantage of the tri configuration would be it will be able to “tack” faster, but with 3 hulls in the water I doubt even that. The option to build in FRP or aluminium is interesting. It indicates that these tris are purely custom builds. This design is about luxury first, making an environmental public statement second and a thing to “sail” last. As with the 300 foot Black Pearl monohull sailing yacht, that is claimed to be the most “environmentally friendly” yacht on earth, you could have saved a hell of lot of the environment by not building the boat in the first place. Sorry.

    The jpegs give the idea.
     

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    Last edited: Sep 24, 2022
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