Wayne.B wrote:
Anyone here have any experience with roll stabilization tanks -
designing, building, tuning, etc. ?

I'm talking about passive roll stabilization using port and starboard
water tanks connected by a "slosh" tunnel. If sized properly the
water sloshing between the tanks will be out of phase with the roll
period and dampen the motion, even at anchor.

The "slosh" tunnel would need to be as big as the tanks, diameter-wise, and
a huge amount of water would be needed to have any effect whatsoever. If you
don't believe me. take an overweight friend sailing and get him to lose
weight by leaping from side to side in phase with the roll, always moving to
the "up" side. He/she would need to weigh in at around 500lbs if you can
find such a person.

If this system worked the QM2 would use it instead of spending $millions on
stabilisiers.

DP

On Sun, 30 Dec 2007 09:41:10 GMT, "Dennis Pogson"
wrote:

Wayne.B wrote:
Anyone here have any experience with roll stabilization tanks -
designing, building, tuning, etc. ?

Undoubtedly not.

I'm talking about passive roll stabilization using port and starboard
water tanks connected by a "slosh" tunnel. If sized properly the
water sloshing between the tanks will be out of phase with the roll
period and dampen the motion, even at anchor.

Yes, this has been known to work, at least somewhat.

The "slosh" tunnel would need to be as big as the tanks, diameter-wise, and

Absolutely not.

a huge amount of water would be needed to have any effect whatsoever.

It does take fairly large tanks, the one big drawback to the idea.

If you
don't believe me. take an overweight friend sailing and get him to lose
weight by leaping from side to side in phase with the roll, always moving to
the "up" side. He/she would need to weigh in at around 500lbs if you can
find such a person.

I can't find a way to comment on that utter nonsense.

If this system worked the QM2 would use it instead of spending $millions on
stabilisiers.

What they have is better and they use it. This does not mean that an
arrangement of tanks cannot work at all.

Casady

DP

Richard Casady wrote:
On Sun, 30 Dec 2007 09:41:10 GMT, "Dennis Pogson"
wrote:


Wayne.B wrote:

Anyone here have any experience with roll stabilization tanks -
designing, building, tuning, etc. ?


Undoubtedly not.


I'm talking about passive roll stabilization using port and starboard
water tanks connected by a "slosh" tunnel. If sized properly the
water sloshing between the tanks will be out of phase with the roll
period and dampen the motion, even at anchor.


Yes, this has been known to work, at least somewhat.

The "slosh" tunnel would need to be as big as the tanks, diameter-wise, and


Absolutely not.


a huge amount of water would be needed to have any effect whatsoever.


It does take fairly large tanks, the one big drawback to the idea.


If you
don't believe me. take an overweight friend sailing and get him to lose
weight by leaping from side to side in phase with the roll, always moving to
the "up" side. He/she would need to weigh in at around 500lbs if you can
find such a person.


I can't find a way to comment on that utter nonsense.

If this system worked the QM2 would use it instead of spending $millions on
stabilisiers.


What they have is better and they use it. This does not mean that an
arrangement of tanks cannot work at all.

Casady

DP




I doubt it will work passively.
Control of the phase is most important - and won't coincide with the
roll.

Think great big powerful pumps?

In article , Richard Casady wrote:
On Sun, 30 Dec 2007 09:41:10 GMT, "Dennis Pogson"
wrote:

[snip]

If this system worked the QM2 would use it instead of spending $millions on
stabilisiers.

What they have is better and they use it. This does not mean that an
arrangement of tanks cannot work at all.

Surely the water wouldn't slosh until the boat started to heel, and then
it would slosh to the lower side aggravating the situation rather than
helping it. Then, as the wave passed, and the boat was prepared to
return to upright, the water would be slow to slosh back 'up-hill' - it
would counter the mass of the keel. Wouldn't that possibly put a boat at
a potentially bad angle to the next wave?

Justin.

--
Justin C, by the sea.