Aftmast rigs???

Discussion in 'Sailboats' started by jdardozzi, May 28, 2002.

  1. upchurchmr
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    upchurchmr Senior Member

    There are a few "minor" differences besides the mast position.

    They have nothing whatsoever to do with cruising boats typically discussed in this thread.
     
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  2. DennisRB
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    DennisRB Senior Member

    Each time those extreme race boats get posted as "aft mast" the same relevant point gets made. Its a case of long bows out of the front rather than masts put at the back. Same thing you say? Well no point in repeating the differences yet again. Scroll back a few pages where it has been discussed in detail.

    Not dissing the idea. I like sailing with a main. I just hate raising it, reefing it and storing it. So a little less main and more area in furling sails out the front is a good idea for cruising too. It means less engine hours in the real world where short trips means raising the main just isn't worth the effort.
     
  3. brian eiland
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    brian eiland Senior Member

    "When sailing upwind most of the surface of the jib is oriented in the direction of the motion, while most of the surface of the main is oriented perpendicular to it, the leech often even pulling back."

    Did you manage to look thru a lot of the material presented there by WB Sails,....quite a knowledgeable gentleman & outfit.
    http://www.wb-sails.fi/en/contact-us/wb-sails-story

    http://www.wb-sails.fi/en/contact-us/wb-sails-crew

    http://www.wb-sails.fi/en/sail-technology/technologies---videos

    And you did note this image?
    ThinkOne2s.jpg
     
  4. brian eiland
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    brian eiland Senior Member

    A number of these newer boats are moving their rigs back to counter the bow burying tendencies of those tall mainsails, and to take better advantage of their headsail areas.
    I chose to eliminate the mainsail.

    The racing monohull, Wild Oats, made quite some modes to move her rig back,....mentioned a few here on this page and some photos
     
  5. upchurchmr
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    upchurchmr Senior Member

    Brian,

    Please discuss the quote I was talking about - which you originally quoted.
    Not much of a discussion when you ignore the actual words that I took exception to.

    I still have an article of the first time I saw you state your mast aft theory about 20+ years ago (maybe 30 years ago). You still are not making your case by not addressing the issue - skipping to something else as a distraction.
     
  6. brian eiland
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    brian eiland Senior Member

    Is this the 'original quote' you speak of,...that I did not respond to??

    If so, here is another noted sailor and sailmaker's viewpoint
    Sails in Combination
     
  7. upchurchmr
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    upchurchmr Senior Member

    Yes that was the statement that I re-quoted.
    And you still didn't respond.
     
  8. tgtony52
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    tgtony52 ...

    I thought this thread was about "Aftmast rigs" which not only includes boats with masts positioned on the transom but any sailing boat (cruising or not) with a mast positioned aft of the middle of the boat.

    I also thought that state of the art boats with masts 60 per cent back from the tack of the foremost sail would be not only relevant to this thread but would also be of significant interest to those who believe in aft mast rigs ( for whatever reason).

    I believe that these "extreme race boats" are absolutely relevant to all the discussions within this thread as they show that moving the position of the mast further aft is part of the answer to improved performance. Like any other sport, technologies developed in racing have spinoffs beneficial to the rest of us, we just have to recognize it.
     
  9. DennisRB
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    DennisRB Senior Member

    Brian's whole idea is to move the mast back to make the main very small if not get rid of it entirely. His assertions are that better aerodynamic performance comes from less main and more headsail.

    There is a subtle but major difference which most people seem to understand. When comparing working sails, these boats still have large mainsails compared to the headsails like they have always had, so are aerodynamically similar. The same rig is being moved back to prevent nosediving by way of longer buoyant bows for a hydrostatic/dynamic difference. The mains are not tiny and being replaced by headsails. The longer bows mean similar "flying" sails are now connected to the deck as bow spits are not needed or can be much smaller. Overall there is less nosediving. The rigs are similar, there placement is different. The standard mainsail is a crucial piece of the rig as always, and has no sign of becoming vestigial equipment soon to be phased out.

    To allow a more buoyancy at the bow so the boat could carry more sail without nosediving. How much smaller did they make the mainsail Brian?
     
  10. brian eiland
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    brian eiland Senior Member

    As I said before go have a look at similar descriptions of the interaction of the headsail with its trailing sail (albeit a mainsail or maybe my mainstaysail)

    http://www.hk.northsails.com/TIPSADVICE/Howdosailswork/tabid/10496/language/en-US/Default.aspx
     

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  11. CT249
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    CT249 Senior Member

    Brian, isn't the relevant part of Mikko's post the piece where he says "it would be wrong to think that the jib is more important". That demonstrates quite clearly that he does NOT think that the jib is a more important sail.

    Secondly, no really good sailor oversheets their mainsail, by most definitions.
     
  12. CT249
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    CT249 Senior Member

    And the trend in design in many of the fastest craft has been to get rid of the jib altogether, and just use a mainsail. So we can all pick and choose individual classes to "prove" our points all day long, and in the end it will prove nothing.

    There are probably well over 10,000 boats that have been built to the rules of one class I sail in. My boat, as modified by me, may well have its rig further aft than any other boat in the entire class, so I'm not saying that mast forward works better. The point is that (as others have said) mast positions and rig designs are influenced by so many factors that we can't just point to any one design as evidence of broad trends or proof of concept.
     
  13. brian eiland
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    brian eiland Senior Member

    I was NOT trying to say that he thought it was the MORE important of the two sails,...but it certainly is important. "in charge of most of the forward driving force'. And yes, it can not do this on its own, it needs the helping hand of that following sail.

    I was referring to a number of discussions that occurred on the Sail Aerodynamics subject thread (I believe it was), where there was much discussion of sheeting the mainsail up & often over center to provide a 'flap effect' in order to point higher. I call it over-sheeting.
     
  14. brian eiland
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    brian eiland Senior Member

    WOW, have a look at this latest video
    https://www.youtube.com/watch?v=kw-e2k5Ddpo
     

  15. Spiv
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    Spiv Ancient Mariner

    You should go and teach this guy how to sail.
    Apparently he prefers to sail with two reefs in the main, staysail and reacher.
     

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