Old Quarter Tonners -Magic Bus

Discussion in 'Sailboats' started by steveo-nz, Oct 5, 2008.

  1. sean9c
    Joined: Jan 2011
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    Location: Anacortes,WA

    sean9c Senior Member

    Too much ballast too low and too much sail area. Laurie designed that hull for the high CG of the internal ballast and the rig size he originally had on the boat. Chances are by basically putting bigger everything on the boat you've just over powered that little hull. Any chance you kept the old stuff? Going back to that configuration would likely make a nicer sailing boat.
     
  2. quartermaster
    Joined: May 2009
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    Location: california

    quartermaster Junior Member

    CRM,
    Ours is not to question why, ours is but to do or die... I ran into Jim Antrim after the Great Pumpkin, and I pigeon holed him on my rating, as he crabbed sideways, he muttered something about the rating should neither win us races or lose us races, but be a neutral ground. I think they compared the boat to similar modern designs and extrapolated a best guess from there. The 117 downwind, is a bit much though. I don't know where they got that!
    Quartermaster
     
  3. quartermaster
    Joined: May 2009
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    Location: california

    quartermaster Junior Member

    Overpowered or Overrated

    I didn't keep much of the old stuff. The boat was badly damaged from all the repeated wipe outs from the downwind legs. The mast was broken in three places , the deck at the partners had a patch three foot square, the cockpit was broken and plywood plates were screwed on until it was three inches thick in some places. The decks were rotted and broken in numerous places. The bricks had come lose at some point and had wreaked the interior . I don't think the boat was as stable or as easy to sail as you think. Now that the boat has the present configuration, I haven't had any of the damage issues that it had before, and yes, I have broached, a massive four time broach in the Delta Ditch, and she came back up, no worse for wear. I think really the only issues I have are in high winds on the Bay in Summer, and if I take the time to reef, even the little rudder is not a problem. I push the boat pretty hard, and I guess I expect a lot from it. Your right, it is a little boat. It looks big, but actually it is quite small.
     
  4. CRM
    Joined: Aug 2009
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    Location: Port Townsend, Wa. USA.

    CRM Boat Builder

    Quartermaster is a poet

    You're right, I love and can so picture that familiar crab walking sideways. The illusion or hope of being a neutral arbiter has been the father of many magazine articles. In the long run the whole Cabal just puts people off racing, The Darwinian factor.
     
  5. Paul B

    Paul B Previous Member

    Book arrived today. I have to hold back from cracking it open, as I'll need it in a few weeks while confined in a tin can flying for 12+ hours.

    One suggestion: Upgrade the packing for overseas shipments. The corners are not well defended against the rigors of postal employees.
     
  6. Paul B

    Paul B Previous Member

    I have finished the book and it was a good read.

    I did run across a number of factual errors that you might want to address in any reprints.

    Examples:

    Page 3: the formula you mention is not simply (the square root of waterline length). This is repeated a couple of times throughout the book.

    Page 30: North Star was not a Chance design. It was a Peterson.

    Page 54: Sweet Okole did not win the 1977 SORC. Imp was the top scoring boat.

    There were a number of others I noticed but I did not make notes on all.
     
  7. salkbj
    Joined: Jan 2010
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    salkbj Junior Member

    -North Star II, a 3/4 tonner from 1977 was designed by Chance Jr.

    -Sweet Okole did top class C.
     
  8. Paul B

    Paul B Previous Member

    You are correct. However, the book is specifically discussing the 1974 Half Ton Cup winner. That boat was not a Britt Chance design.


    Correct Again. However, the book states, "Sweet Okole was the winner of the 1977 SORC in Florida..." That seems to indicate the overall winner.
     
  9. Richard 4073
    Joined: Feb 2010
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    Location: Auckland, NZL

    Richard 4073 Junior Member

    Thanks Paul for those comments, yes, I will have the book amended to note that Sweet Okele was the winner of Class C of the 1977 SORC, and Peterson as the designer of North Star. The square root of waterline was a phrase used to distinguish the theoretical performance of a displacement boat against those that can plane - there is a constant that can be used as a multiplier (but I think this is a variable figure?).
    I appreciate the feedback which will ensure that it is an accurate historical record, and I'm glad that you found it a good read. I was fortunate to have half an hour on the national sports radio here in NZ with Peter Montgomery a couple of weeks ago to talk about the book and the era in general.
    cheers
    Richard
     
  10. Paul B

    Paul B Previous Member

    I should have made better notes about the other factual problems I found in the book.

    The constant you are looking for is 1.34*the square root of the WL. This is the "theoretical hull speed".

    I did enjoy the read and owe you a thank you for putting forth the effort. Hopefully you'll be rewarded by at least breaking even on your costs.
     
  11. SloopJohnB
    Joined: Apr 2007
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    Location: NZ

    SloopJohnB Junior Member

    Richard

    Received my copy of your book last Friday, too busy to start to read but a quick flick thru started for bring back the old memories of the IOR scene, measuring and assisting Paul with the ratings.
     
  12. Richard 4073
    Joined: Feb 2010
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    Location: Auckland, NZL

    Richard 4073 Junior Member

    Hi JohnB, good to hear your copy arrived, hope you enjoy reading it. It would be great to hear some of your personal recollections of working with Paul W sometime.

    Thanks too for your comments PaulB - break even is certainly a long way off, but it has been a very satisfying project pulling the material together.
     
  13. Paul B

    Paul B Previous Member

    I ran across an interesting article in the June 1983 issue of SAIL magazine. It addresses the measurement of the stern on IOR yachts. I'm sure 99% of the people who read SAIL at the time simply flipped the pages. I'm posting a few of the diagrams attached to the article here for information.

    What it shows is the genius the great designers had to have. Remember, these were the days before the personal computer. All calculations were done by hand or by using a pocket calculator.

    So not only did the designers have to draw a fair linesplan, they had to do so and have the resulting boat float within <1/4" of the drawing. The shape not only had to be fair, it had to fit the multiple measurement points at no more than 1/8" deviation.

    After all this the design had to be faster than last year's designs.

    Simply remarkable.
     

    Attached Files:

  14. Richard 4073
    Joined: Feb 2010
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    Location: Auckland, NZL

    Richard 4073 Junior Member

    Those are great, thanks for posting Paul. The maths involved was indeed complex, and if it wasn't hard enough on the drawing board it then all had to be physically measured from the finished boat!
     

  15. Paul B

    Paul B Previous Member

    That was probably as difficult as designing the thing.

    A small mistake by the measurer could result in a rating far higher (or lower) than the boat was designed for. When we got our first computer to run the rule we got a Compaq Portable. It was the size of a small suitcase, with a tiny monochromatic screen.

    We could take this box dockside while the measurer did the in-the-water freeboard measurements. With a crude little LOTUS 123 spreadsheet we could plot the freeboards and spot any small discrepancies in the measurer's work.
     
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