CBTF smashes Transpac record/ Waterballast dead?

Discussion in 'Sailboats' started by Doug Lord, Jul 24, 2005.

  1. Doug Lord

    Doug Lord Guest

    Congratulations to Morning Glory the z86 CBTF maxi for setting the pace. Seems like Pyewackett her sistership will also break the record as well as a couple of others.
    Congratulations also to CBTFco and Reichel/Pugh a mighty impressive combination.
    Among many interesting things in this transpac are:
    1)-the fantastic downwind performance of the boats despite many "knowledgeable " people saying the forward foil doesn't work well downwind.
    2) this was the second major head to head between all three z86's: two CBTF and Windquest using waterballast. The CBTF boats won in the Bermuda Race and have won again here . I wonder what the implications are for the use of waterballast as compared to canting systems? It probably depends a lot on the type of race and the rule but in the z86 class the answer is pretty clear.
     
  2. usa2
    Joined: Jan 2005
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    usa2 Senior Member

    you get more leverage with the canting keel so in most cases its superior. Off wind the WB boats can dump it if they so choose so the become lighter.
     
  3. cyclops
    Joined: Feb 2005
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    cyclops Senior Member

    Logic says: New boats will have: CBTF with water ballast!
     
  4. yokebutt
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    yokebutt Boatbuilder

    Too late Cyclops, Mari-Cha 4 and several open sixties already have it. In fact, the last generation sixty have the CG of the tank coincide with the CG of the boat at 10 degrees of heel, (static inclination limit with full cant) and voila´, it doesn't contribute to heel! Better yet, it also gives the boat a bit more punch going upwind in sloppy conditions. Them Frenchies are pretty clever sometimes, perhaps red wine really is as good of a thought-lubricant as beer.

    Yoke.
     
  5. yokebutt
    Joined: Aug 2004
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    yokebutt Boatbuilder

    P.S. Of course, they all use canting keels with assymetrical daggerboards, wich has absolutely nothing whatsoever in common with CBTF. (TM), (R), (Pat.), etc.

    Yoke.
     

  6. John Perry
    Joined: Nov 2003
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    John Perry Senior Member

    I dont think that argument is quite right. Generally speaking a monohul sailboat which is too large to be stabilised by crew weight HAS to have a certain amount of ballast to be seaworthy. So if you wish to augment righting moment one option is to move that ballast sideways (canting keel), another option is to add waterballast off the centreline. If you look at it that way the waterballast option is heavier than the canting keel option other than the situation when the waterballast is dumped, in which case it is the same weight.

    But weight is not the only issue. A disadvantage of canting keels is that they generally need some extra appendage(s) to maintain lateral resistance when the keel is canted. An advantage of canting keels is that they can work with a narrow hull which will probably have less drag (water and air) and better self righting capability.

    Of course, for even more righting moment, you can combine waterballast with a canting keel.

    John
     
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