Jim C says:

Don't the go-fast guys use these systems to roll tack?

Not sure I'd call it a real roll tack, but it is referred to as a "gravity
dump", saves pumping time ;-)

snip instructions

Sounds like fun, but it might be hard on opened beers, sunbathers and galley
crockery.

It's most hard on those sailing around you, as your boat, with no increase in
wind strength, goes from 10 degrees of heel to 30 degrees of heel, then tacks
and appears more stable.
It's also fun to wait for someone to "drag race", and THEN load up water
ballast. Suddenly the boat springs 10 degrees or so more upright, and gains a
lot of speed.
Happy days!

Steve

Morgan O says:

Are they sold on the consumer market, or are they only sold to enginering
consultants, system developers and alike?

Being good businessmen, they will usually sell to anyone. Or at the very least
tell you who your nearest dealer is.

Steve
Stephen C. Baker - Yacht Designer
http://members.aol.com/SailDesign/pr...cbweb/home.htm

Perhaps a simple arrangement for water ballast tanks, although I haven't
heard of them in a dingy, would be to have two ball valves at the back of
the tank handy to teh skipper, one to let the water in through a hose or
pipe, and the other to let the water drain out into the bilge where it can
be sucked out with an automatic bailer, eliminating the need for pumps. in
a dingy an automatic bailer is a small hole in the bottom of the boat with
a door that can be opened when the boat is moving. the motion of the boat
through the water sucks any water in the bottom of the boat out through
the hole in the bottom of the boat. an automatic bailer is handy for
emptying out a dingy after a capsize but they do cost money. Sometimes
dingy's have holes in the transom so any water getting into the boat runs
right out the back.

For cruising I imagine there would be watertight compartments under
the fore deck and perhaps under a rear deck for keeping one's
bedding and spare clothing dry, so draining water balast inot the boat and
out an automatic bialer or the transom would not be a problem.

On the subject of ball valves, I installed them under the sinks in my house
last spring for $3.50 each from the plumbing department at the local home
improvment store. These are only 1/2" diameter pipe which many coul d take
a couple of minutes to fill or drain a balast tank on a dingy. Don't
install ball valve handles anywhere they are likely to get turned by
scrambling feet or a tangled mainsheet.

I imagine a dingy with two centreboards, a jib sail, a reefing main
sail, and water ballast tanks, would be a challenge to operate and
would keep a sailor pretty busy.

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And it's not nearly as obvious as having the whole crew move to the windward ama.
Has water ballast been done in multihulls? It could be useful in controlling
pitch, too.

Stephen Baker wrote:
SNIP

It's also fun to wait for someone to "drag race", and THEN load up water
ballast. Suddenly the boat springs 10 degrees or so more upright, and gains a
lot of speed.
Happy days!

Steve

Morgan Ohlson wrote:
On Thu, 04 Nov 2004 11:33:52 -0400, Terry Spragg wrote:


Morgan Ohlson wrote:


Is "tap" a proper word for water-pipe switch?

I'm looking for some kind of tap /switch to open /close the tubing to the
ballast tanks.

Since one of the main goals is to keep empty weight down beg metall things
is not acceptable.

The pipes (plastic hoose) must be 15mm (dia), maybee 20-30mm.

Hints please!


Morgan O.

I use a plasic ball valve on 1/5 inch id (38.1mm) hose for my toilet
plumbing. Smaller sizes are available. Cost about 15 bucks, uses
threaded hose barb adapters. Seems OK so far after one season of
use. Available at home hardware stores.


From which area do they stem? House plumbing, caravans ???


Morgan O.

Plumbing. (plastic, not plumbus lead)

Recreational vehicle dealers also handle some special toilet
plumbing, but it is not as robust as most water supply pipestuff.
being lower pressure.

Terry K