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Re: More ballast
Originally Posted by jimgo
I can understand your point. If you think of the boat as a fulcrum and lever, if he's putting the weight at/near the DWL height, he is essentially putting the weight over the fulcrum, where it won't do much good. Putting that weight farther out on either "arm" of the lever (e.g., putting it in/near the bilge) would be more effective. That makes a lot of sense to me when you're looking at counteracting heeling.
But what about the idea of simply adding mass to the boat? Won't that increase the inertia of the boat, which would make it less susceptable to things like small-height chop, or the wakes from passing motorboats? I can see where having the weight lower in the boat would also help with this kind of stability, too (essentially fore/aft rather than lateral), but wouldn't the added mass, in general, help change the boat's characteristics in this regard?
Sorry, if this I'm missing something fundamental. I'm an electrical engineer, not mechanical or Naval Architect, and haven't been around sailboats long enough to have played with these kinds of things, either.
No inertia if the added weight is at the fulcrum. Inertia is a mass
, & the rotational acceleration at the longitudinal 'axle' of the boat (DWL) is trivial. You could pack 500# of lead tightly around the fulcrum of a see-saw, and it will operate at much the same natural frequency. Put five pounds near the ends, you have altered both its moment arm and moment of inertia. Angular momentum, style of fing.
The OP might benefit from reducing weight aloft -- isn't every pound at the masthead worth about seven pounds in the keel? But the sad fact is, the Neptune 24 CB is a heavy boat with 35% ballast ratio, soft curves, and a really shallow keel:
It necessarily carries its ballast high. It will have a long, slow rolling motion. Some people find that unpleasant. Others prefer it to the sharp, choppy motion of stiffer boats. It's all down to your inner ear. Weighting the CB might help; replacing the halyards, switching to laminate sails, maybe even re-rigging with Dynel might help. But basically, this boat is what it is. (Pleasant-looking boat, BTW -- I likey.
Albin Ballad 30, Fionn
Last edited by bobmcgov; 04-26-2013 at 12:17 PM.