Biplane rigs

Discussion in 'Multihulls' started by cutawaycafe, May 15, 2013.

  1. tomas
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    tomas Senior Member

    Is there any disadvantage to the top cross-member joining the mast pair?
     
  2. T0x1c
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    T0x1c Junior Member

    Actually you can't do without the top cross member with stayed rigs. The masts are stayed on one side only, so the cross member brings the stress on the other mast shrouds.

    You can use eg aluminium in stayed rigs, or thinner carbon cylinders, resulting in a cheaper rig.
     
  3. rob denney
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    rob denney Senior Member

    Michael,

    Congratulations. Looks good.

    You were going to send them to me?

    You don't "have to import" Duflex. In less time than it takes you to Z press the panels, you could build a table then infuse your own, for half the price and a better job (no joins). Build a KSS boat and eliminate much of the filleting and tabbing as well.

    Not for me. I would not have a stayed rig on a cruising boat, even if it was free. The cheapest rig is a self built unstayed carbon mast, mounted in the middle of the boat if there is enough bury, or in a hull if not. There are many aspects of boat building which are more difficult and demanding than building a mast.

    It looks like a difficult lead on the plans, and I suspect Jeff (Schionning) would have specc'ed 2 if he thought it was possible. Your logic could also be applied to the reacher and spinnaker.

    You have done your research into the costs of standard stayed rigs. But then you write off unstayed rigs based on one number (without details or a breakdown of costs) from a one off boat on the other side of the world. This does not seem to be an unbiased approach to the cost issue.

    You say they are "not reasonable" (a step backwards from "theoretical") but don't say why, except that not everyone has one (Richard Woods' silly argument). If you want your opinion to carry some weight, you will need to back it up with reasons (facts, numbers, experience, etc). You might also want to read Gerald Barrink's comments on his biplane rigged boat at http://diy-yachts.com/distribution/...12beaaf007ad0546ef992&rb_v=viewtopic&start=70

    Parlier's boat was Médiatis Région Aquitaine (stayed biplane rig cat) and was made more complex (offset masts, strut, winches, backstays, etc) so it could fly extras. It solved few of the problems inherent in stayed rigs, with the negatives (2 of everything, complexity) of biplane rigs.
    Team Phillips was Pete Goss' 120'ter (unstayed biplane) which proved that huge righting moment (21m beam x ~18 tonnes weight) was not a problem for unstayed rigs and nor was no extras.
    Neither Radical Bay or Coolchange sail the apparent wind downwind. Nor will the Wilderness'.

    The unstayed wingmast is not on the plans, the unstayed tube mast is. The stayed wing mast sail area is the same 57 sq m as the stayed tube mast so presumably the same applies for the unstayed ones. No idea what Mike's is. An unstayed rig can carry larger sails than a stayed one as a) the added weight of an unstayed topmast is lower and b) the top flexes in strong winds, reducing power.

    Derek is a very smart chap and I have learnt a lot about build techniques from him. However, on rigs we differ.
    His main selling point of the Twins rig is that Cool Change (wing mast/biplane, same as the Wilderness', but not on a stub mast or folding) works so well, but was expensive, both of which I agree with. However, the Twins Rig removes most of the advantages for the very nebulous cost decrease. The Cool Change rig was costly to build back in the days of >$100/kg carbon and before low cost build methods (it was infused, but not in one piece).
    Also:
    The weight of the Twins rig may be less (I doubt it), but the cog will certainly be higher and this is what affects pitching.
    The complexity and cost of the strut and rigging will outweigh the cost of carbon in the masts, which as I showed previously is small in the total mast cost.
    Maintenance: It is bad enough having stays to check 10m up in the air, without worrying about a strut and it's connections as well.
    Difficult to use. On an unstayed rig you can ease the sail to 180 degrees or more for hoisting, lowering, reefing and depowering. One of the Twins rig hits the cross piece and the shrouds at less than 80 degrees. Heavy weather gybing with runners is even more rigorous than a normal stayed rig due to the runners and one sail being restricted by the strut and shroud.
    Windage from the strut and rigging.
    All the usual worries about a rig made up of many small parts, the failure of any one of which brings the masts down.
    Using (and moving) the halyards to the bows to keep the rig steady in strong winds does not sound either practical or fun, especially when reefed.
    The shrouds to the middle of the cabin are like stayed masts in reverse. ie pulling up instead of pushing down on structure that is mostly unsupported. The added structure to do this is considerable and in the place where headroom is required.
    Stepping and unstepping will be more difficult/expensive.

    Derek and I have discussed this elsewhere, the end result was to wait and see how the rigs worked, cost and weighed. Any time now.

    rob
     
  4. T0x1c
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    T0x1c Junior Member

    Hi Rob,

    Sent.

    You might not be aware as you don't have follow CE regulations, but building with panels having guaranteed structural properties allows you to save between 10 and 15% in weight on the structure: you can use ISO 12215-5 El-a evaluation method, instead of the conservative El-C method.

    Got it. 70k is pocket money for you, unfortunately I am not in a position to reject a free mast.

    Not a question of lead. Jeff (Schionning) designed all first Wilderness designs with two. Then two have been added on the 'X' versions.

    True, I am very far from having your experience of unstayed rigs and costs. But I don't think Kelsall based his similar opinion on one rig only.

    Anyway, on rig costs we agree to disagree, the fact whether 70k is big or small amount is a totally subjective matter.

    Finally we agree!
     
  5. groper
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    groper Senior Member

    Toxic, why do you need CE certification? Can you not build a boat out of whatever you want and if it floats go sailing? I would understand if for commercial vessels, but for private too?

    If not, then can you not make your own panels and get them tested by a registered testing facility - the cost of which would be much lower than importing duflex from here...very expensive stuff...

    Ive looked at prices of composites all over the world, Australian prices are the highest ive found anywhere. Anyone commercially manufacturing in australia, is importing their own composites from overseas for this very reason... we can only dream of living in europe for composites supply, the fact your considering a pre-manufactured product like duflex from here is simply baffling?

    Im sure some of the best spar manufacturers in the world are in france/germany, why not contact them and find what a carbon wingmast will cost you in real terms? If you really want to save money and still have carbon, build your own carbon mast - its really not as difficult as it might seem.
     
  6. rob denney
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    rob denney Senior Member

    You'd spend a large pile of money ($6k in freight, plus duty, local taxes etc) importing an already expensive product in order to save 10-15% of the "structure" (~1,500 kgs) which is 150-200 kgs (2 people) rather than build it yourself from raw materials?
    If the EC considers you capable of assembling your boat from a pile of 8 x 4 sheets, then they should also consider you capable of producing full length sheets yourself. Or get a certified builder with a table to infuse them for you.
    AFAIK, Derek has a couple of boats being built in Europe, so presumably there is a way around it.

    Sorry, but you haven't "got it" at all and are once again quoting out of context.
    I said I would not have a stayed rig on a cruising boat. You ignore the oft repeated and obvious fact that a biplane wing masted rig is not the only option for an unstayed rig.
    I also said that you should put a value on the advantages of unstayed rigs before criticising people who use them.

    Why would he do this if 2 were sufficient? If you wish to have a boat with spinnaker, jib and screecher and only 2 winches, go for it. But comparing a rig you have minimalised with one that we have no detailed costing of is unreasonable. As are over hyped statements such as "7 times the cost".

    Maybe, but you don't seem to let that get in the way of telling me I don't know what I am talking about on the subject.

    Only one of his boats is an unstayed biplane, none of them have unstayed single masts, and he did not ask me for an up to date price, so I suspect he had little choice but to base his costs on Cool Change. He had not costed the Twins rig when we discussed it, so comparison was impossible. I suspect he still hasn't. When he does, he will find it is more expensive.

    We don't disagree on the cost (2 rigs are more expensive than one, wing masts are more expensive than tube masts, etc) but on the value.
    You want a fixed, stayed rig because "everyone else has one" and you don't care about the hassles of owning and using it.
    I prefer an unstayed rotating tube mast as it is easy to use, safe and maintenance free, for the same overall price as yours, but much cheaper if I build it myself.
    Mike considered it to be "not a major cost consideration" to have the benefits of unstayed rigs, two masts, the added efficiency of wing masts, the stubs to allow him to easily lead his halyards aft and the fancy bearings to facilitate mast trim.
    The other 2 guys are prepared to pay for all this and then some more for the added benefits of easily dropping the masts to go under bridges.
    Everybody is different. I don't see what the problem is?

    Thanks for the mast quote you pm'ed me. It is 10% shorter, the section is 20% lighter and hence much less stiff than the one on the Wilderness plans. In terms of comparisons with Ozone's rig, you missed out the 10% gst (tax) that Mike would have paid, and used an exchange rate which is 10% higher than reality. It also lacks equipment which is on the mast plans.

    I spoke to Etamax. Mike's/Ozone's masts are not folding. My mistake. Sorry.
    The updated price list for an unstayed wing section mounted on a stub mast with self aligning bearings for a Wilderness 12 type cat is ~$30,000 each, depending on what is required. An unstayed tube mast (same as we are using on the 50' harryproa) is $17,000, including plain plastic bearings. I still maintain this would be cheaper than a comparable stayed rig, if the boat was built for it. ie, all the extra bits required for the stayed rig are excluded.

    rob
     
  7. T0x1c
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    T0x1c Junior Member

    95/25/CE certification is for the private leisure industry, not for commercial. There are some countries in the EU (e.g. France) that allow amateur building with a local certification, but then it would have absolute zero resale value.

    Prices excl. VAT:
    Mast 3814 Euros
    Boom 659 Euros
    Footplate 270 Euros
    Standing ring 1408 Euros
    Running rig 766 Euros all Dyneema
    Facnor furler 1210 Euros
    Genoa 1155 Euros
    Mainsail 2340 Euros

    Total: 11 622 Euros excl. VAT = 17 780 AUD incl. 10% GST; so 11% under the 20 KAUD estimate I gave previously. Sorry for not having a quote for exactly the same length, but these 11% will easily cover the difference in length of mast. And it is suitable for max 17 T.m righting moment with SF 3.

    In terms of missing equipment, I believe you're mistaken: my quote includes boom, furling genoa and running rig, the 70k Ozone figure does not.

    Sorry Rob, never said that. But you try hard to make people believe that two carbon masts are not that expensive, and that the price for an aluminium stayed rig would not be far. This I can't and won't buy. Ozone rig costs 3.5 times the one of a conventional rig, you can't twist the figures that much.

    Nope. I would love two unstayed masts, but again it is too expensive for me. Would the price be not far -as you try to prove-, I would without doubt chose the biplane rig. Anyway as Kelsall and yourself agreed, it is urgent to wait for developments.
     
  8. T0x1c
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    T0x1c Junior Member

    We drift away from the topic of this thread, but briefly:
    Would you build e.g. a Wilderness 1230 in Europe, then
    1. SD won't give the CAD drawings; only for this reason, you can't build your own panels.
    2: You will add around 400 kg to comply with the ISO 12215-5 minimal skin thickness requirements. Hence not losing an additional 200 kg is critical.
    3: The additionnal 200kg are increase in panels core thickness. Meaning a hell of a lot of trimming, or redesign of all 3D drawings/panels/nesting. And of the whole boat, as you would change longitudinal CB.
    4: You would need 5 panel testings per property, hence around 25 laboratory testing. This would be very expensive for a one-off build.
    5: Building your own panels is not less expensive, especially for the tooling and considerable tool bits needed to cut the panels, the amount of vacuum consumable, the post-curing of the boat etc. Not mentioning the valuable months spent building these panels.

    This is why nobody builds with self-made panels in Europe. The standard for amateur building here is moulds or strip planking.
     
  9. Herr Kaleun
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    Herr Kaleun Junior Member

    Been off-line [off-shore...]lately and this thread has moved on I see...
    But the gist of the argument for/against bi-planar rigs appears to be down to cost...
    Let us remember that it is down to persons like ourselves and the serious naval/yacht designers to 'push the envelope' in innovative design [this notion follows for all forms of design...], taking into account impact upon the environment [and all that encompasses...], cost, ease of production, use and efficiency.

    I am in the process of constructing an RC model that I will test [on a local reservoir...] the efficiency of a 'quadra-planar' rig [four sail, double schooner on cat hull]. However, it is not just the efficiency of the QP rig that I am interested in, I am also wishing to take this design on and use solar-pv fabric in the the construction of the sails [Solar Kinetic Sails, as I am naming the system...]. The power generated will be used to charge batteries, linked to twin ndm-motors, experiments will be ongoing in the efficiency of a motor sailing mode, hopefully to assist propulsion in low or non-existent airs.

    You [particularly TOX1C...] may all consider this design interest mad, foolhardy, a waste of time or money, :confused: but they said the same thing about the Wright bros, or even Leonardo Da Vinci...:idea: [madness and creative thinking seem to be established bedfellows...].

    Instead of worrying so much about how much its going to cost, let us try and get down to the nitty-gritty of design criteria, facts, figures and above all empirical data.

    As soon as I have my data from my own experiments I will be glad to publish them to you all... Regardless of the outcome, it is FUN!:p
     
  10. groper
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    groper Senior Member

    Many people build their own boats in Europe... And they do their own laminations... There are countless examples in blogs on the net. Why do you feel you can't do your own laminations? Are you sure you know the rules correctly?

    As for schionning designs, they have a a relationship with ATL composites and have a vested interest in specifying their materials for their designs. They cannot redesign a boat to use different materials without extensive reengineering - which ATL did it for them. T avoid the additional engineering cost they will try their best to talk you out of it. I can't prove it, but I also think they receive a commission on the duflex for every kit they sell.

    Now I'm not knocking this relationship, many companies do similar in all industries. But duflex Is not the be all and end all choice for boat building. I could have bought duflex for my boat and supplied the CAD drawings to have it all cnc cut, but I chose to build my own full size panels and I do not regret this choice 1 bit. I also feel better about using foam core instead of balsa.

    Back to the rig, it's not fair to compare prices from different countries. My engines cost $28k in Australia, in the USA the exact same japanese made engines are $15k... Go figure...
     
  11. rob denney
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    rob denney Senior Member

    Herr Kaleun,
    Any details on the solar sails fabric? Look forward to seeing the model, but why 4 masts/rigs? 2 rigs if there is not enough bury for the single mast (catamarans), or there are space/handling constraints (some harryproas), but 4?.

    Toxic,
    An unstayed biplane wing masted rig will always be more expensive than a fixed, stayed alloy mast.

    My comparisons have been with single unstayed tube masts (the wing mast/stub masts on the biplane rigs are the first we have built), where the difference is much less. And becomes negligible if you include the extra gear and beefing up the stayed rig requires and the cost of maintaining it. Then put a value on the benefits of sailing with the unstayed rig to determine which is the better rig for you.

    If you want unstayed masts for least cost, build them yourself. It is far simpler than many other parts of building the boat.
    ............................
    Thanks for the more detailed quote, but I would like specs as well if it is to be much use. And the suppliers' name. It is your decision on using a mast that is ~25% lighter than the designer specifies.
    ............................
    Your problems with Schionning Design and panel certification are beyond my understanding and interest, except that in Aus and NZ it is far cheaper to make your own full length panels than buy and glue together 2.4 x 1.2m sheets.

    For a start, you are not paying 2 middlemen and shipping costs from one side of the globe to the other and back again.
    The core is the expensive part. Making each panel exactly to shape reduces wastage from 10-20% down to zero.
    It is recommended that Duflex panel joins are glassed over (the join is only 80% the strength of the rest of the material), which is another step, more materials and more fairing.

    The above may not be deal breakers. But self made panels can be rebated, tapered, have variable thickness and density cores, different fibre layups, tabs and fillets, and a variety of edge treatments. None of which is possible with Duflex. The amount of work and additional materials this can save on the boat is enormous.
     
  12. Herr Kaleun
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    Herr Kaleun Junior Member

    It's early days for the info on whether the solar-pv fabric can be employed, I'm still researching this avenue myself, but take a look at the tent designed as a joint venture between the erstwhile 'Orange' and Kaleidoscope
    [Google it...], which was unveiled for the UK Glastonbury Festival. The idea of true solar sails is a concept I have been toying with for a number of decades [!], originally musing over sewing individual 'wafers' to an existing sail [!!!]. Of course, now educated to ship stability etc.. I realise that the weight would be a serious issue [changing the mass of the sail and thus the metacentric height etc... Not to mention the wiring headaches!]. I knew that there was experimentation with a process for pv coating of warp, which has lead to the 'Orange' tent... Tis only a matter of time that this new tech will be light [...and affordable] enough to use in traditional sails. My SKS [Solar Kinetic Sail] design is exactly that. So we have a sail that acts like a traditional sail, but will generate electricity from the sun as a by-product.

    "Every Little Helps"

    As for the 'Quadra-planar' rig... Well, there is a lot of discussion here about using 'Biplane' rigs on cats, with more pros than it seems cons... My idea, that will be experimented on the RC model will be free standing masts stepped fairly for'ard and aft of each hull [almost junk like] and will carry tall wing sails, one on each corner of the hull plan. With the possibility of adding staysails [though there might be a need to stay the masts in this idea...].

    I have only just downloaded 'Freeship' CAD, still trying to get my head around how to use it, but when I have a design to publish, I'll post it.

    This is a 'design forum', where interested dudes like ourselves can bandy around ideas, however implausible or eccentric. Cost, as far as I am concerned is only relevant when the idea has proven itself enough to go to the next level of production and manufacture. Talking of cost at such an early stage of 'brainstorming' is defeatist, [if cost was always discussed at the early stages of designing a rocket engine, we'd have never got to the moon...]. However, critical analysis of ideas, such as the mathematical and engineering constraints is vital and welcome in these discussions. [Check out the thread on hybrid motor systems, posted elsewhere on this site [http://www.boatdesign.net/forums/boat-design/hybrid-engine-systems-sustainability-46678-new-post.html]; Mr Harris of Salisbury gives a very useful counter argument to the scenario, with prudent and informed breakdown of the maths...

    Lets leave out the time consuming and boring matter of cost, until it is relevant. :p
     
  13. T0x1c
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    T0x1c Junior Member

    Groper, could you please give me examples of blogs for the construction of yachts in Europe in flat panel with self-made lamination? I am looking for this type of experience. As previously advised, most amateur builds use male plugs or strip planking in Europe, and lamination is done on the boat.
     
  14. T0x1c
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    T0x1c Junior Member

    Absolutely not. As you state yourself, "cost is only relevant when the idea has proven itself enough to go to the next level of production and manufacture." Hence the discussion of the biplane rigs, which I think have already proved themselves.
     

  15. groper
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    groper Senior Member

    I don't know of "flat panel" builds, but how is it different from foam strip plank or mold built? The lamination is still completed by the private builder and so there is no certification or test results to say the quality of their laminate or guaranteed strength etc... Why do you feel flat panels should be treated differently?
     
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