A bluewater, ocean going water ballasted matorsailer. Why not?

[xarax]

1. There seems to be a consensus that the existing water ballasted motorsailers are not suited for true bluewater, ocean going sailing.
2. But I still do not know the theoretical reasons, if any, that a bluewater, ocean going motor sailer could not exist someday ! The advantages of such a craft, if feasible, would be obvious.
3. I think it would be more useful and productive, instead of pointing the limitations or problems of the existing boats, to try to figure out how a solid build, self righting water ballasted motorsailer would look alike.

[Fanie]

instead of pointing the limitations or problems

Eh Xarax,

I think that is where one should start, pointing out the problems - unless you can find a way around the obvious then there may not be much point in forcing it, or else the advantages must outweigh the drawbacks to justify it.

Imo any boat can be made self righting, but I think for most it is a matter of can you live with the compensations.

[TeddyDiver]

1 There's no such boat
2 It could, but the low density of water creates limitations
3 Fat compared to it's metal ballasted counterpart

I'm building a partly water ballasted motorsailor (1t water, 1.4t lead)

[Fanie]

I think the first thing one would attempt to get by is the keel ande weight. This is going to require a lot more energy for propulsion.

Personally if I want to make a motorised boat simply use a displacement cat hull like the sailers and just omit the mast and sails. Light, economic, shallow, spacious, stable, bla bla bla.

[PAR]

Water ballast in a motor sailor is an oxymoron, a misnomer.

Water ballast was a fad, that is now all but past, fortunately. By best description, water ballasting is a marginal advantage to a racer, battling fixed ballast/fin brothers in arms.

Water ballasting has no place on a motorsailor, frankly, because it's a crappy way to add weight. It's only advantage was the ability to pump it from one rail to the other, but with canting keels, the advantage is gone to a much more effective arrangement. No motorsailor will sail well enough to need this level of adjustment.

[xarax]

Originally Posted by TeddyDiver

1 There's no such boat

I agree. But I dont see why there can not be- and will not be - such a boat...

Originally Posted by TeddyDiver

3 Fat compared to it's metal ballasted counterpart

[quote=TeddyDiver;288251]
So What ? It could be slower under sail but faster under engine, while motoring without the ballast weight.

Originally Posted by TeddyDiver

I'm building a partly water ballasted motorsailor (1t water, 1.4t lead) :

That may be a nice solution, too.

[xarax]

Originally Posted by PAR

Water ballasting has no place on a motorsailor, frankly, because it's a crappy way to add weight.

Lead keel balasting itself is a crappy way to achieve righting momentum to a sailing craft, compared to the floating hull of a cat, a tri or a proa, but the number of multihulls is still greatly smaller than that of the monohull lead mines...

[apex1]

Originally Posted by xarax

Lead keel balasting itself is a crappy way to achieve righting momentum to a sailing craft, compared to the floating hull of a cat, a tri or a proa, but the number of multihulls is still greatly smaller than that of the monohull lead mines...

It seems you do´nt like to understand?

There is NO WAY to have water ballast in a motorsailor! period

[xarax]

Originally Posted by apex1

There is NO WAY to have water ballast in a motorsailor! period

When I listen the NO WAY "argument", I remember that it was used on heavier than air vehicles, supersonic speed, man on the moon, etc...
I dont say that one can take an existing motorsailer and add water ballast on it ! I say that one could, possibly, design and build a sailing vessel that uses water ballast to right itself only while sailing , so it could be lighter while motoring without it. WHY there is, and will never be, a way to have a craft like this?

[Fanie]

While everything is possible, as I have indicated the compromises may not be worth the effort. I would think that a couple of the guys responding on the matter have some experience to a more or lesser degree on the topic, so if I could make a suggestion, approach very cautiously unless you have a lot of money to dump on something that may turn out a disappointment.

[apex1]

Originally Posted by xarax

When I listen the NO WAY "argument", I remember that it was used on heavier than air vehicles, supersonic speed, man on the moon, etc...

Jaja......................

It is always a pleasure to quote Paul Ricchelli, so:

Originally Posted by PAR

Water ballast in a motor sailor is an oxymoron, a misnomer.

Water ballast was a fad, that is now all but past, fortunately. By best description, water ballasting is a marginal advantage to a racer, battling fixed ballast/fin brothers in arms.

Water ballasting has no place on a motorsailor, frankly, because it's a crappy way to add weight. It's only advantage was the ability to pump it from one rail to the other, but with canting keels, the advantage is gone to a much more effective arrangement. No motorsailor will sail well enough to need this level of adjustment.

Maybe if you read it slowly, you come after the issue.

[Squidly-Diddly]

pure sail boat with transferable water ballast and somewhat flat bottom like a MacGregor.

It was about 40' and built by a 'home builder'. He had sailed it to South Pacific and back, said it worked very well.

this was not the airplane hulled "Cosmic Muffin" boat with the website.

[TeddyDiver]

A sandbagger style water ballast ain't no bluewater cruiser solution. Fractional water ballast makes sense only using the actual water tank capasity (made floodable) and placed accordingly to increase stability.

[xarax]

Originally Posted by TeddyDiver

A sandbagger style water ballast ain't no bluewater cruiser solution. Fractional water ballast makes sense only using the actual water tank capasity (made floodable) and placed accordingly to increase stability.

But these water tanks could well be made as large as we wish, couldnt they ? And we can always throw the "water bags'' away and put them again on board when wa will need it, which was not possible with the sand bags.
I think that the main advantage of a water ballasted motorsailer would be the increased speed while motoring without the weight of the water ballast, not the increased stability while sailing with the help of it.

[Crag Cay.]

Xarax,

Your ideas do have some merit, although ultimately it would need a lot of work to evaluate whether they are the best way to achieve your aims. Ultimately they may prove to be 'false dawns' but don't give up as this stage.

If I read you right, your primary aim seems to be variable displacement. This does indeed have appeal for being able to maximise efficiency under power versus sea keeping as conditions dictate.

Then, 'stiffness', as in the ability to carry sail, would primarily come form form stability, but could be enhanced by asymmetric filled gunwale ballast tanks.

But it's the ultimate stability that everyone assumes will be the problem with boats like this, but being a 'motor sailor' does hand you a trump card in this regard. A self righting ability may be possible by the design of a high, large volume, structurally sound deck house in the style of the UK RNLI lifeboats. Here's it's the inverted volume of these structures that provides the righting couple, rather than a deep, ballasted fin keel. Such a cabin house could be compatible with the aesthetic style of a 'motor sailor'.

I would start your evaluation with a simple, single chine hull, plenty of flair to the topsides so WL Beam increases markedly with displacement, a full height wheel house above the weather deck, twin engines and rudders, (so it can dry out upright) and a simple dagger board for lateral resistance.

Then get it into HydroMax and see.