Carter 33 adding ballast to the keel

Discussion in 'Stability' started by Yorgos, Dec 27, 2013.

  1. Yorgos
    Joined: Dec 2013
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    Location: Athens, Greece

    Yorgos Junior Member

    Hello from GREECE, i am considering to add ballast at the end of the keel of my Carter 33. At the sailboat data i find disp 3.400 kg and ballast 1.300 kg, but all the boats that have been built here in GREECE from the Olympic have been estimated around 4.700 kg, so it is logical that they are tender a lot more than other similarly designed boats. And it is. 4 crew in the cockpit and if one goes at the sidedeck the boat feels it and leans. with wind Force 4 it's leaning a lot and i have to reef. with Force 7 double reef and jenoa not reaching the mast i see water on the sidedecks.
    I would appreciate some advice.
    thank you
     
  2. alan white
    Joined: Mar 2007
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    Location: maine

    alan white Senior Member

    The boat will lean into those flattish bilges and stay there but going beyond that angle would take a lot more wind due to the bulging topsides that give you that tumblehome shape. Adding ballast will add a significant load to the root of thew keel which in that design is a weak point due to lack of a large enough radius.
    Some 33s have been reinforced at the keel root and many have cracks along the radius of the keel root. More ballast especially at the bottom of the keel without the reinforcement isn't a good idea.
    I don't think the addition of ballast will help you to sail more upright to any degree. The hull form was designed to address angle and clearly, the boat will always want to sail on that flattish bilge. That boat won the around Denmark race in '72 at an average speed of something like 7 kts. I believe the displacement should be about 8000lbs.
     
  3. PAR
    Joined: Nov 2003
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    Location: Eustis, FL

    PAR Yacht Designer/Builder

    Welcome to the forum.

    The Carter 33 is a first generation IOR and of course has a set of shapes "sculpted" by these rules, particularly aft and in her entry. Because of these design choices, she lacks power (to a degree) so this style of hull shape will prefer to sail farther over then a more modern set of shapes. In other words it's really not fair to say she's tender, compared to more modern shapes, given the compromises of the early IOR shapes employed in her. In force 7 winds, you're darn right she'll need a deep reef in her sail plan as will most all racer/cruisers in 33 MPH wind strengths.

    For her era, her ballast/displacement ratio is pretty good and typical. She could tolerate some additional ballast, though this could create other issues, such as upgrading the rig and appendage attachment for the increased loading. She has a 1.68 m draft now, but the ballast is concentrated in a lead casting at the bottom of the fin. This casting could be removed and recast into a bulb, lowering it's mass and if desired also lowered a touch. If you added another 150 mm of draft and the casting converted into a bulb, maybe with a beaver tail, you'll gain some advantage, though the hull shape will still offer the handling characteristics of the early IOR era she's developed for (just slightly stiffer).

    To directly answer your question about adding about 30% more to her displacement as ballast (doubling the ballast), well I think this is way more then the boat can tolerate and still offer good performance and handling. Simply put, adding a ton and a half more to a 3.3 ton boat, just isn't reasonable. I do think you can remake the ballast casting with an additional 400 - 500 Kg, possibly hung slightly lower, with little concerns, but certainly not anywhere near the 1,300 Kg, you are suggesting.
     
  4. Yorgos
    Joined: Dec 2013
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    Yorgos Junior Member

    thank you for your advice. My thinking was for 280 - 300 kg ballast, and reinforce the inner area of the keel's base. and actually put the ballast at the rear half of the keel, because i have some really heavy tiller as the wind pipes up. ( the keel is two parts, separated vertically, and i suspect that only the front part has ballast). I first have to reef the genoa.
     
  5. PAR
    Joined: Nov 2003
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    PAR Yacht Designer/Builder

    The ballast needs to stay in it's current relative position. Shifting it aft will just upset the boat's trim angle and likely her handling as well. Your heavy helm issues will probably need to be addressed separately. The rudder, skeg and the rake on the 33 all bother me, particularly when similar designs from the same designer in the same era look much more effective. His other models show a vertical post, sufficient aspect area and substantial skeg, while the 33 has a fair short aspect, scrawny skeg and a lot of rake. I have no sailing reports on the 33 and you'd be best advised to look at rig tune first, but if that was my boat, I'd be thinking about a different rudder/skeg configuration if raking the stick wasn't much help.
     
  6. Tad
    Joined: Mar 2002
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    Tad Boat Designer

    Contact designer Yves-Marie Tanton about this, he was chief designer for Carter when this boat was designed.

    http://www.tantonyachts.com/

    Also realize that if you increase the righting moments of your boat (by either lowering ballast or increasing it) you will need to then consider strengthening the rig and chainplates.
     
  7. Yorgos
    Joined: Dec 2013
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    Yorgos Junior Member

    thanks Tad, he told me better to lower the keel, but this expensive and difficult for me. i think also to put a thicker frontstay, double babystay ( old style ), and double backstay.
     
  8. Yorgos
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    Yorgos Junior Member

    what if i put the jenoa frontstay on a bowsprit 60 cm, and make a second one semipermanent for a small jib to help the weather helm. Besides that i was thinking about adding a small balancing area on the low and in front of the rudder, but it seems dificult to be trusty.
     

  9. Yorgos
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    Yorgos Junior Member

    Happy new year!
     
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