I think we agree in principle. I was talking fore-and-aft trim more than
roll stability. It would seem to take an inordinate amount of ballast in
the belly to get much improvement in roll stability, I think. I don't know
if the cement blocks really help much, but they can't hurt. Early Potters
like mine didn't have the blocks. I do have about 13 lb of cement that I
poured into a cavity under the mast step when I rebuilt the v-berth.
I had to have batteries for my electric outboard, so I placed the two 45-lb
batteries as low as possible and centered slightly forward of the
centerboard). With my tiltup trailer, the added weight has not caused
launching difficulty, but I probably have to crank a little harder to pull
the boat back up on the trailer.
Does Jerry's lead ballast weigh only 15 lb? I would think he would need
more than that to have much effect, even in the bow locker. But Jerry's
_Breezy_ is fast, at least with Jerry or Todd at the helm.
For an otherwise empty P15 with an outboard, 50 or 100 lb of ballast in the
vicinity of the mast would not be too much. I carried a couple of sandbags
on the forward part of the v-berth on one race. I don't remember whether
they were 25 or 50 lb each.
Smith designed the boat to carry a lot of heavy stuff forward, but with an
empty cabin and a crew in the cockpit, the boat is inherently out of trim.
I'm reluctant to carry "human ballast" in the cabin when wind and waves are
up because I worry about someone being able to escape in the event of
turtling. (Of course if we used Solar Fry's suggestion to use Miami corpses
as ballast, that wouldn't be a problem.)
Harry Gordon
P14 #234, Manatee
Mountain View, CA
<snip>
>Harry, I think your racing examples indirectly reinforce my original point
>about
>"smart" ballast. With humans as ballast, as opposed to immovable mass, they
>"ballast" can move to where it is most useful, be it to windward or up to the
>bow..
>
>I view adding some weight in the bow as quite different than adding weight in
>the bilge. The first serves a purpose of "trimming" the boat and a little
>weight
>goes a long way since the mass is being placed so far from the center of
>buoyancy. Jerry B. has remarked several times that adding 15 pounds of
>lead to
>the chain locker is effective. I like to think of it as nicely balancing
>against
>the 25 or 30 pounds of outboard that most of us hang off the stern.
>
>Adding ballast in the bilge, I believe, is being done in an attempt to gain
>stability and righting moment. Trailerable boats similar in size to the
>Potter
>have to use several hundred pounds of shoal draft keel to make this work.
>Because the mass is close to the center of buoyancy and therefore has little
>"leverage" it takes a bunch to gain adequate righting moment. As other folks
>have already pointed out, you then have to drag all that weight through the
>water, up and down the launch ramp and down the road.
>
>As to improving performance and safety, I think that, on an hour for hour
>basis,
>time spent improving one's sailing skills will yield far greater results than
>spending time adding eclectic combinations of sandbags and foam. The
>Harrys and
>Jerrys among us having been sailing their little boats for decades without
>capsizes or other disasters and can sail circles around the rest of us in
>a test
>of speed..
>
>
>Dave Kautz
>P-15 #1632 Tilly Lucy
>Palo Alto, CA
>
>
>
>______________________________ Reply Separator
>_________________________________
>Subject: Re: P-15 Ballast
>Author: Non-HP-hlg (hlg@pacbell.net) at hp-boise,mimegw7
>Date: 6/16/99 8:15 AM
>
>I'm sorry, but I'm going to have to drag out ol' Stanley again:
>
>"I have always found the boat goes better, and performs properly, with
>weight in the cabin. Never be afraid to load her with gear and equipment.
>She was designed to carry masses of people and their gear. But do remember
>she will be badly handicapped if this is placed too far aft. The forward
>third of the lee chine must be allowed to do its job."
>
> -Stanley Smith,
>_October Potter_
>
>In my experience, I find the Potter slows down as you add passengers mainly
>because everyone rides in the cockpit, which weighs down the stern and
>lifts the bow. Many years ago, when I hardly knew how to sail at all, and
>had never raced, Manatee, starting from behind, beat about five other
>gunter rigs or Mk I's in a casual race from the Alameda ramp upwind to Jack
>London Square. My crew consisted of my wife (who wasn't feeling well)
>reclining in the cabin with our two small children. My tacks had been
>sloppy and too long, and I had no idea how I ended up in front of the pack.
>
>Years later, in a more formal Potter Yachters regatta, I raced with my son
>(probably about 100 lb at the time) as crew, riding on the foredeck. We
>almost won the gunter class, but we were nosed out at the finish line by
>another gunter rig. The skipper and crew of the winning gunter rig each
>weighed at least 250 lb, and the crew was sitting on the foredeck with his
>legs hanging over the bow.
>
><snip>
>
>Harry Gordon
>P14 #234, Manatee
>Mountain View, CA
>
> >