Aspect ratio on headsail vs shroud angle?

Discussion in 'Hydrodynamics and Aerodynamics' started by sailingdaniel, Aug 18, 2011.

  1. brian eiland
    Joined: Jun 2002
    Posts: 4,955
    Likes: 181, Points: 73, Legacy Rep: 1903
    Location: St Augustine Fl, Thailand

    brian eiland Senior Member

  2. Paul Scott
    Joined: Sep 2004
    Posts: 303
    Likes: 8, Points: 0, Legacy Rep: 84
    Location: Spokane, Wa

    Paul Scott Senior Member

    Paul Elvstrom showed, a long time ago, in the Dragon Class, which by class rules has two jibs (basically blade and overlapping), that leaving the overlapping sail up in the big stuff and luffing the main won races. I don't think that has changed, has it? In the Dragon class, at least.

    Paul
     
  3. Paul Scott
    Joined: Sep 2004
    Posts: 303
    Likes: 8, Points: 0, Legacy Rep: 84
    Location: Spokane, Wa

    Paul Scott Senior Member


    I understand that, but I actually have an experiential tale- when we bought our U20, I bought the class legal full sail ( fat head ) with a reef point, and the class legal high wind sail ( pin head). 9/10 th rig. Both sails by Glazer. The reef point brought about the same luff length as the high wind sail.

    The pin head was incredibly hard to handle in a breeze, in comparison to the fathead. The pinhead felt just like, well, a pin head. Jerky, foul mouthed. It was the ability to twist the fat head smoothly off the wind, both actively and passively that left the pin head in the garage. I was going to have a high wind fat head or even a squarehead made, but never got around to it.

    Against other U20's in bigger winds, it was because of the staggering nature of the pinhead that you could see the fatheads move forward with each jerk of the pin head. Big time. No imagination required. 3-5 feet per stagger. Fatheads were just smoother. And this was on a rig that DID NOT BEND.

    I would never ever go back to a pinhead, especially in big winds. The closest I would go would be a highly roache pinhead, but if we keep Amati, I'm going from our current highly roached pin head ( looks like a Hobie 16 main) to a fathead or small squarehead. In 1999 I couldnt talk Lidgard into a fathead, and the pin head jerks around in higher winds. Bleah.

    Paul
     
  4. sailingdaniel
    Joined: Apr 2011
    Posts: 50
    Likes: 2, Points: 0, Legacy Rep: 20
    Location: around the world

    sailingdaniel Junior Member

    Thanks all for great answers on this now old thread..

    I have been sailing , sailing and sailing and havent had much time to think about design for a while.. I now reached Brasil and now i have time to relax and dream again ! :)

    I wasnt able to really test moving my cutterstay to leward as. The wind was not strong enough for my small cuttersail and whit waves and current i could not say if i helped ore not.. But i know for sure that it did not make anything worse so im optemistic..

    But my genoa who was cut down from a low cut 150% to a high cut 110% was better in almost every wind then the "old" one and much easier to control.. In very light winds to windward the old big one was better.. I add a pic on that genoa and the alwaysaonthebeamperfectsailing i had in madagaskar..

    An other intresting thing is whit the smaller 110 genoa is that i could sail faster on a broad reach whit the sail to windward whit the pool.. And i could go suprisingly "high" in the wind like this.

    The answer about stay angel in my origenal question seams to me be: There is nothing "wrong" whit a stay angel of say 23 deg if the boat is long enough to find a place to fit the lower en of the stay.. And 0 ore 1 deg would be ok if it would not be to close to the mast and the mast would be strong enough !!! :).. In other words, other things in the design seams to control the stay angle....

    Cheers

    Daniel
     

    Attached Files:

  5. brian eiland
    Joined: Jun 2002
    Posts: 4,955
    Likes: 181, Points: 73, Legacy Rep: 1903
    Location: St Augustine Fl, Thailand

    brian eiland Senior Member

    Shorter Rig, lower AR

    I was trying to remember a real good discussion on this AR subject and off centerline sheeting of bigger headsails,....and then I got lucky and rediscovered these excellent discussions,...good subject thread.

    Why was I looking? Recently a reference to this video of a VERY FAST ocean racing multihull was posted on another forum:

    Aboard the world's biggest trimaran - Spindrift 2. Matthew Sheahan discovers what makes the giant record holder tick and how Yann Guichard plans to race her across the Atlantic singlehanded in this year's Route du Rhum
    https://www.youtube.com/watch?v=Ac-wP3Zcu7o


    Have a look at timeframe 3:29 for an overall view of the new shorter rig.
     
    Last edited: Jun 6, 2016

  6. brian eiland
    Joined: Jun 2002
    Posts: 4,955
    Likes: 181, Points: 73, Legacy Rep: 1903
    Location: St Augustine Fl, Thailand

    brian eiland Senior Member

    Good subject thread that seems to have gone dormant
     
Loading...
Similar Threads
  1. revintage
    Replies:
    11
    Views:
    1,111
  2. Will Fraser
    Replies:
    150
    Views:
    23,972
  3. amjams
    Replies:
    12
    Views:
    4,695
  4. Autodafe
    Replies:
    29
    Views:
    6,319
  5. philSweet
    Replies:
    4
    Views:
    3,449
  6. DCockey
    Replies:
    153
    Views:
    36,502
  7. 23feet
    Replies:
    5
    Views:
    69
  8. JohanH
    Replies:
    11
    Views:
    2,024
  9. CocoonCruisers
    Replies:
    5
    Views:
    1,034
  10. motorbike
    Replies:
    19
    Views:
    3,795
Forum posts represent the experience, opinion, and view of individual users. Boat Design Net does not necessarily endorse nor share the view of each individual post.
When making potentially dangerous or financial decisions, always employ and consult appropriate professionals. Your circumstances or experience may be different.