Monohull Speed: Speed Dream by Vlad Murnikov

Discussion in 'Sailboats' started by Doug Lord, Jan 8, 2010.

  1. RHough
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    RHough Retro Dude

    I agree. There are huge holes in every theory I've seen about a non-multi being faster in the 50+ foot range. These stories always go something like. "If we can get some new magic system to work, then we will faster than a multi." They never consider that if the magic system works on a boat with a natural disadvantage, those same systems will work that much better on a boat that is naturally faster. As soon as you insist on Manual Power Only 99% of these things are non-starters ... if all it takes is powered systems, then you cannot target multi's that don't use them.

    Once you get into powered systems, it would take less power to cant the rig of a multi in to a lifting position and to swing 50+% of the vessel weight in ballast around.

    I really don't see the point of doing all that work just carry a mono-hull label.

    R
     
  2. P Flados
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    P Flados Senior Member

    The post #206 concept does have an advantage or two over a traditional tri.

    There would only be one "cross beam" it would be smaller, lighter and more aerodynamic than typical. The tank/pod would also be much smaller than a typical ama. Not shown in the drawing would be the shrouds from the mast to each tank/pod. The shroud to the extended pod from the mast would carry the weight of the ballast. In the rare event the outboard tank/pod goes in the water it will be on the windward side. This keeps structural loads on the beam very very low compared to those for a tri. This is what would allow use of a small single beam.

    From an areo standpoint the tank/pods are also smaller than a typical ama and the leeward pod/ama is normally retracted into a recess on the hull.

    The wing profile for the beam would be for a small negative vertical lift. This helps with gust response.

    The above combines such that stuff hanging out in the air with potential for drag (beam and windward tank/pod) is kept to a minimum and these items can be easily profiled for good aerodynamics.

    The overall wind resistance for the entire boat would be much will be lower than for a tri.

    The cant on the ring and the dagger board are preset at very good angles regardless wind, and with only one hull it is big enough and long enough such that there is no real risk of a pitch-pole.

    On the downside, any normal run would be intense. Again, this is not a cruiser or day sailor layout. Normal sailing would be with lots of sail flying and constant heel angle adjustment via rudder and/or rig trim. Tacking/gibing would need to be more deliberate and may required co-ordinated effort from multiple crew members. The boat would also need some serious skill in optimizing hull shape. This is not an area where would I would claim even average skill.

    Also, I will be the first to admit that it is all just pie in the sky thinking unless someone else does something (not likely). My interest are not in fast monos, and my resources would not even be a drop in the bucket for this type of thing.
     
  3. CT 249
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    CT 249 Senior Member

    Gary and Randy are dead on the money, if we take smaller boats as a model.

    This concept could be seen to be like a giant International Canoe, with all the handling issues that implies. Having sailed Canoes and played with water-ballasted big boats a tiny bit, the handling issues in a giant IC make me shudder. On a smaller scale and as a fun dirt-cheap twilight racer it's something I sketched, but basically it's pretty much pointless; if you want a fast, simple twilight racer you're better off wandering down to the local dinghy or cat club and getting your mates to all buy old Tornadoes or skiffs and starting your own race. It'd have as much point as using dynamite to catch fish in a contest against guys using dry flies.

    But the main point is that an International Canoe cannot even come close to holding a fast cat. The only time I did the IC nationals, we shared the course with the titles for a 14' surfcat, like a Hobie 14. I know the relative standard of sailors, because at the time we were racing on of the top 14 sailors with our own cat.

    The Canoe was slightly slower than the 14' surfcat, which is just what the national yardstick says. Up against a comparable-length performance cat, the Canoe had no chance; one day I went out for a blast while my wife sailed her cat around with no jib and three kids on board, and she slaughtered me for pace.

    Ballasted monohulls are a joy to sail and wonderful boats to own, but they just don't go as fast as a multi of equivalent design most of the time. That doesn't worry many people, just like it doesn't worry chess players that a pawn can't move more than one space, just like cricketers aren't worried that they can't intentionally protect the wickets with their legs or bowl with a bent arm, just like Hobie 16 sailors don't worry when they get beaten home by A Cats or F16s, or just like archers don't get worried that they don't use laser sights.

    PVlados' giant windsurfer concept is exactly what I used to daydream about sometimes when sailing around on my board as a teenager, but again the handling issues and engineering issues are beyond practical application within the reasonable future (if ever) and if we get to that stage technologically, then something different would probably have arisen.

    One thing that seems completely at odds with current design is the idea that a fast mono should be as beamy as a '77 Farr centreboarder.... the modern boats are trucking and they are skinny.
     
  4. Doug Lord
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    Doug Lord Flight Ready

    Speed Dream

    ====================
    Oh, I don't think so. The application of lifting foils to large monohulls is in its infancy and offers tremendous potential-both the DSS type, Vlads version and my version. The Moth has led the way in small boats and when that technology moves up large monos using it will likely be faster than multihulls using "foil assist" or no foils. Of course, if Hydroptere is successful with her Pacific campaign the bar will be raised again for multihulls...


    Randy-so thats what a "Retro Dude" looks like!-Nice pix......
    ======

    Worlds fastest 30' monohull (maybe) :
    (click on image)
     

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  5. P Flados
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    P Flados Senior Member

    Doug,

    I have to say although this is fun to think about, practicality and risk make large multi beating mono's pretty unlikely.

    There is a huge underlying weakness in trying to scale up moth style operation. If you loose focus for a minute in a moth you are swimming. If you get above 25', more than 2 sailors, and more than 25 kts, you go from a given "occasional swim" into serious risk for boat damage, injury or worse.

    For open water distance records, there is a need to be able to maintain good headway while running in rough conditions in the middle of the night. The traditional lead keel mono's and the big tri's have evolved to handle this stuff. Heck, they have got the state of the art good enough that a large tri can be operated single-handed. I do not see Vlad's concept beating the multi's in this game.

    Hanging lead off of the side of a big mono to approach multi performance just to break the not very meaningful mono distance records does not sound like a high value activity when you consider the risk.

    If you want to make a leap in performance, I think you have to depart from traditional boat design completely. Huge kites, monster flip tackers, scaled up versions of the Swedish wing/para-vane boat and other such concepts can be developed that would have staggering top speeds and the ability to operate in really nasty conditions. But any of these concepts would be huge undertakings. It is probably more realistic for actual contenders to just try to tweak a little more from existing Tri technology, rather than take a gamble and spend the time and resources to try something entirely new. Sponsors/investors will see a lot more value in a big fast tri program than in something unproven.

    When you drop back down to two guys and a trailer sized boat, leveraging off of moth tehnology gets to be less of a stretch. I still do not see any huge wave of popular acceptance given that cost, complexity and handling issues will exist. There will be some, and eventually these may prove to be real hot rods. However, a 16' to 20' cat will still be the "hot rod" of choice more often than not.
     
  6. Doug Lord
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    Doug Lord Flight Ready

    Foilers!

    ==================
    Since a Peoples Foiler does not exist yet, you're probably right. But the fact remains that the little 11' monohull is faster than all cats under 20' and that says something about the technology. The Moth has proven that the technology is viable for high performance-the next stage(for small boats) is to show that the technology is adaptable to an "easy to sail, fun boat for the whole family"-in other words-a Peoples Foiler.

    When -and if- the economy improves there will be more people willing to take a risk with foils for ocean racing-and a risk it is.
    What I hope will happen with Hydroptere is that they will prove that they have the technology to making foiling in the ocean practical-which MUST include collision avoidance technology for small things at the surface or just below the surface.
    The "60' Moth" concept is not impractical it just needs a lot of development to be feasible for ocean racing-and I imagine at some point we'll see it.

    --------
    PS-I love multihulls and there is a lot of development potential there too-particularly in under 20' high performance trimarans......
     
  7. Doug Lord
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    Doug Lord Flight Ready

    IMOCA 60's

    Apparently, I've missed some major developments over the years since 2007-namely the use of lifting foils in ocean racing by Open 60's. I noticed this at the start of this years Barcelona World Race and started a thread: "Open 60 using curved lifting foils"-namely Virbec-Paprac 3, Foncia, Mafre, PRB and Safran. http://www.boatdesign.net/forums/sailboats/open-60-using-curved-lifting-foils-35710.html
    This is astonishing to me since I've thought I did rather extensive research.
    But the spectacular news is the lifting foils have been used since 2007 on Open 60s with good results.
    An idea of the speed:

    From Sails and Sailboats-roughly translated by google:
    On sailing canting keel, fins are usually inclined outwards so that the drift downwind approaches the vertical when the boat heels. On Foncia , this inclination was reversed (it is 9 °), so that the wing is even more lying in the water, and plays a supporting role, relieving the bow and facilitating the planning.
    "Our monohulls now have speed close to polar multihulls for years 85-90, precisely the time we started to equip them with foils" says Mich'Desj '.


    http://www.voilesetvoiliers.com/cou...chel-desjoyeaux-j-ai-navigue-a-bord-de-foncia
     
  8. jeri carla
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    jeri carla New Member

    but but but

    Seems there is no analysis/engineering behind, just a sketch of dreamer.[/QUOTE]

    dreams are what reality is made from
     
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  9. Vlad M
    Joined: Mar 2010
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    Vlad M Senior Member

    dreams are what reality is made from[/QUOTE]

    Absolutely!
     

  10. Paul Scott
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    Paul Scott Senior Member

    Vlad, it seems that there are going to be (at least at times) a lot of foils piercing the gravity interface, which i assume you have allowed for- are leeboards about to make a renaisance? Or is this aussumed to ultimately be a high power/high drag setup?

    Paul
     
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