waterballast set-up for 40ish foot (almost) racing yacht

Im busy on getting info on water ballast while getting busy and inplementing ideas for a 40-ish foot design on a boat.

set up for four tanks, two aft, two sb/ bb.
boat will be about 4.5 meter wide, aprox.

Im looking for a system/ design for these tanks, Ive found some confusing images online,
system must be abel to dump, and pump sb/ bb in a very short timeframe,
(aprox 1000 liters on each side- sb/ bb)
- with what could one pump 1000 liters in a few minutes (5??)
useing a reliable system, preferably with remote controle (pumps/ cocks)
as the boat must be able to be sailed short handed.

any thouhgts, ideas..
all welcome,
if any questions arise, let me know..

 

Here's a thread on water ballast: http://www.boatdesign.net/forums/sa...ansferable-water-ballast-sailboats-47548.html

 

To start with, you need to establish what percentage of ballast will be in the tanks and how it affects stability. Racing rules may have maximum values for both. Also, you ask about dumping the water. Does this mean the plan is to be able to empty and re-fill the tanks at sea?

 

Welcome Patrick, we get all kind of folks here and I can't tell from your post whether you are trying to cobble something together from fish-tank parts or you have a just landed a six figure advance on a boat. Can you give us a bit better sense of the scope of your project and overall expectations of the boat?

 

Hi Phil and Gonzo,

Im gathering info for building a 40-ish foot boat, not being a class40,
In the past Ive been busy with guidance in design, sales and development in fastsailing yachts,

Depending on finances, and the client's desires , we are planning to build a "pretty" fast sailing yacht, boat..

hence my inquiry in getting more detailed info on this waterballast subject, I know about basics, but havent really gone into the matter deeply..

Boat/ yacht would have variable depth, 2 - 3 meters and have a stunning design.. (I'm for a kinda flushdeck design)
As the boat would not be subjected to boxrules, we can go our own way in the design, with all the pro's and cons which comes with not following boxrules..

and yes,
ballast tank would need to fill and dump at sea,
with pumping sb - bb in short time.

IF all goes as planned, as we are looking at it now, ("IF")
we could sail late next summer.. but this depends for a large part on the client,

We know more in a month time for details of this interesting project,

 

What's the point of the water ballast option? Considering the marginal contributions of this contrivance in a cat, unless you're attempting to beat a rule or make trailering more manageable, what's the justification on a 40' yacht? Simply put, water doesn't weigh much, so you need huge volumes to make a significant difference, which eats interior volume rapidly. It's an option, but on a performance oriented cruiser, should be balanced against what it's costs across the several areas it impinges.

 

A canting keel can be more efficient and cheaper to build. Also, it will take less interior volume.

 

First, not to judge, but given your tone, you need to do some serious googlefu. And not just on water ballast, but yacht design as well. As, given what I gather you know about said subjects right now, an NA would tell you the same thing. For he'd have little to no idea what you want in a boat.

You need to specify a lot more parameters than it's length. Which literally should be a sheet several pages long for a full on custom yacht.
Without this kind & depth of info to give to the designer & the builder, you'll be rather disappointed with the result.

If I get the time, I'll dig out a prototype/skeleton of a list to work off of. Though lots of designers have them. And if you're really serious about building, they'll be happy to help. Though you can start right here, with this http://sponbergyachtdesign.com/Adventure.htm article at Sponberg Yacht Design Inc.
Also, Kurt Hughes has a good one here http://www.multihulldesigns.com/custom.htm along with a LOT of insight & experience into boat design.

On water ballast, here's one article - http://www.vgyd.com/Waterballast.html
There's an article in one of the usual sailing periodicals (Sailing World I think) describing both this boat, as well as a VERY abridged glimpse into the design process.
http://biekerboats.com/Bieker_Boats/Riptide_44.html
And do some reading on Bieker's other boats as well. Especially get a copy of the issue of "Professional Boatbuilder" which has a LONG & detailed writeup on both the design & build process on Bieker's design "Riptide 55" http://biekerboats.com/Bieker_Boats/Riptide_55.html

If memory serves, there's also some good, KISS water ballast info in various articles on the Quest 30/33 "Hot Glue Gun" which was set up for single handed racing. And there may be some info on such systems in articles on "Ocean Planet" as well.

Out of curiosity, might not a custom catamaran or similar be a better option? More speed, more space... And if you're going custom it would be easy enough to tune the boat size & features to match the budget, plus the desired amenities & performance.

Also, it's REALLY a buyers market out there on boats. And if you know the general parameters which your client's seeking, you might find something to his liking CHEAP. That, or something similar, structurally, dimension & performance wise to what he's after, then hire a good NA & have it rebuilt to spec. Deck, interior, appendages, H2O ballast, whatever.


PS: Aside from the obvious water ballasted racers out there, there is a one off Aerodyne 38 with water ballast out there. It may even be carbon, I think. Take a look. For it, as well as at the other Aerodyne yachts, for ideas.

 

Thanks for the links, I'll go through them the coming week,

about parameters,
we're still drawing a preliminairy design, this week I'll be discussing things with the builder about design, time, materials and costs,
Implementing waterballast is nessecary due to shorthand sailing, missing 8 - 10 on the high side must be compensated.
A cat/ tri is not required by my client, would be a better alternative for speed..
a canting keel is not an option, would be more expensive and as stated, client wants variable depth, though it could be an (expensive) option.

 

Water ballast increases the onboard labor. Also, the amount of plumbing, pumps, tankage, etc. increases the maintenance and repair times. How does the customer think it will make it easier to sail shorthanded?

 

Sounds pretty simple to me, build some tanks rated for prescribed head & install some plumbing....... these people did it... click a switch to transfer.
http://www.sailboat-cruising.com/water-ballast-system.html

Canting keels add up to some expensive forgings, the bracketing of the hydrolics to structure have seen some issues at times. Water ballast can be low tech with manual backup.
Jeff.

 

There are several "hidden" perks to water ballast, depending on how you set it up. For example, if it's going to be a cruising boat, then it makes sense to design it so that the water ballast tanks are also the fresh water tanks. It gives you a HUGE reserve of potable water, & still allows you to tune your righting moment with water.
And it provides for enough potable water onboard so that a couple could go several weeks or a month+ without needing to go & find a hose to refill things. So then you're not tied to any fixed external supplies as if you had standard sized tanks. Also, for that matter, with such voluminous tanks on a properly setup boat, it'd be possible to keep your tanks full just from rain showers, assuming that you're not cruising for extended periods in an arid region.

That, & if you have a reliable water maker, and the wind goes light or you're running downwind, you can dump most of your fresh water (ballast) & reap the speed benefit of lightening your boat by a significant amount. Refilling the tanks at your leisure, with the water maker, assuming that it's one with a significant production capacity.

Also, properly configured water ballast allows you to alter the fore and aft trim on a vessel. Something which normally is only possible with a full racing crew, & LOTS of sails & hardware for them to shift around as well as relocating their own weight. And proper weight trim can add quite a lot to boat speed, as well as how hard the auto pilot/helmsman has to work. Or at times it even enables you to carry bigger sails, & or carry them at more "profitable" angles, than were you not able to alter the boat's trim thusly. Something which I've seen firsthand, many, many times, adding, or costing the boat several knots of speed.

Plus, if designed in properly, said setup(s) can be a major safety feature. As if much of the tankage is designed along the chines, right where something might try & tear open the vessels hull if struck. Then you make gains there via having a "double hull" in the area.
That, & it's far from guaranteed or ideal, but if the vessel does have a collision, whether it's where the tanks are or no. They can be pumped out, & those which are intact are literally acting as airbags to aid in keeping the vessel afloat. In some cases, to the tune of a few tons of buoyancy, depending on vessel & tank size.
A not insignificant item, particularly if paired with a thickly cored hull, & water tight bulkheads. Such could mean the difference between sinking & not.

You also gain the bonus of a couple of LARGE sized pumps onboard, which are primarily for ballast; intake, dumping, & transfer. However, with a small bit of attention to design, they can serve a secondary function as emergency bilge pumps. Ones likely as big, or bigger than, a vessel's primary damage control pumps.
A setup which has been done on a number of racing yachts with water ballast.

 

as mentioned in the starting post, the boat will be near similar to a class40, but would not compete in that class.

ballast will consist of seawater holding tanks, fed by several punps,

goal of this tread is (for me) to get more insight of the set-up of waterballast tanks,
their workings, calculating ballast needs and size of the pumps (how to feed)

If an owner would go to a tropical resort and spend his days casually sailing, I would gladly help with altering the ballast system to his needs,

as we are now,
we prefer to keep focused on set up, hardware needed and implementation.

therefore insight, tips or links as stated above are more than welcom,
goal of the boat is to sail fast..

 

Tanks that are above the waterline can be simply dumped out with a gate valve and a large drain pipe. Filling them will probably take longer. Do you have a maximum time allowed for filling?

 

Gonzo,

minutes.. size would be a bout 1200 - 1500 liters

each