Enjoy!

http://www.youtube.com/watch?v=epz6BBZm__0

"Charles Momsen" wrote in news:2a53p5.4mg.17.1
@news.alt.net:

http://www.youtube.com/watch?v=epz6BBZm__0

How utterly great! Thanks!

I didn't notice the retrieval lines that controlled the moment of the
ballast until they hauled it back in. Very ingenious....(c;

If Roger's research vessel had these balls.....he'd be home by now....(c;

"Larry" wrote in message
...
"Charles Momsen" wrote in news:2a53p5.4mg.17.1
@news.alt.net:

http://www.youtube.com/watch?v=epz6BBZm__0

How utterly great! Thanks!

I didn't notice the retrieval lines that controlled the moment of the
ballast until they hauled it back in. Very ingenious....(c;

If Roger's research vessel had these balls.....he'd be home by now....(c;

I figured out the retrieval, but how he get the bags out there in the first
place? Help from shore?

"mmc" wrote in
ng.com:


"Larry" wrote in message
...
"Charles Momsen" wrote in
news:2a53p5.4mg.17.1 @news.alt.net:

http://www.youtube.com/watch?v=epz6BBZm__0

How utterly great! Thanks!

I didn't notice the retrieval lines that controlled the moment of the
ballast until they hauled it back in. Very ingenious....(c;

If Roger's research vessel had these balls.....he'd be home by
now....(c;

I figured out the retrieval, but how he get the bags out there in the
first place? Help from shore?




If he filled the bags at the hand rail, that would be more than enough
moment to haul the boat over from vertical by winching on the halyards.
Once the boat started over, the moment arm increases because the mast
tilts out, dragging the bags further and further away from the boat,
increasing their torque on the roll to equal the increasing torque in
the other direction from the increasing moment of the keel bulb ballast
going further and further away from centerline. It wouldn't require
anyone off the boat to roll it over. The slack lines from the boat
directly to the bags to retrieve them back towards the boat, gives him
the decreased moment and torque so the bulb ballast will self right it
after the bridge passage (or after you got the damned thing off the
sandbar...(c

Just winch the bags back into the handrail while slackening the halyards
to prevent the mast from hauling them off the water and she'll stand
right back up again.....very nicely.

I'm more interested in their use to recover from groundings than bridge
passages. To have the self-contained power to lay the boat on its side
to unstick the keel from the pluff mud around here and simply back
yourself off the mud, is worth its weight in gold! This is especially
true when Towboat/US tells you then can get to you in 2 hours while
you're WATCHING THE TIDE GO OUT while aground...(c;

I helped a nice 44' cruiser off the mud by using my 175hp jetboat to
pull on the top of his mainmast to starboard, freeing his bulb so he
could power the ketch off the mud with the handrail in the water...as
the tide was going out, by the way. I kept the pressure on as his 6-cyl
Perkins dragged us both out into the channel where I slacked off to self
right it. Worked great...levers and high school physics....

wrote in message
...
On Wed, 29 Oct 2008 08:59:20 -0400, "mmc" wrote:


"Larry" wrote in message
. ..
"Charles Momsen" wrote in news:2a53p5.4mg.17.1
@news.alt.net:

http://www.youtube.com/watch?v=epz6BBZm__0

How utterly great! Thanks!

I didn't notice the retrieval lines that controlled the moment of the
ballast until they hauled it back in. Very ingenious....(c;

If Roger's research vessel had these balls.....he'd be home by
now....(c;

I figured out the retrieval, but how he get the bags out there in the
first
place? Help from shore?


Maybe turn the boat in a circle to make them swing out, and then let
gravity take over?

it only takes a few degrees shift to start the swing .. but you can read
that in the YouTube article (under 'more info')

Alisdair

On 29 Oct 2008 03:53:52 GMT, Larry wrote:

If Roger's research vessel had these balls.....he'd be home by now....(c;

Except that Roger's boat doesn't have a mast tall enough to create
that much heeling moment and the boat wasn't designed to run heeled
over.

It turns out that you need 36 degrees of heel to get an 80 ft stick
under a 65 ft bridge: 80 x cosine(36 degrees) = 64.72

You can set everything up however without having an accurate
inclinometer or doing any trig. The critical dimension is from the
bottom of the lowest bag to the highest point of the mast. As long
as the halyard is adjusted to less than that length, the boat will go
under the bridge.

On Wed, 29 Oct 2008 12:40:02 -0400, wrote:

Maybe turn the boat in a circle to make them swing out, and then let
gravity take over?

Yes, that's exactly how it is done.

"Larry" wrote in message
...
"mmc" wrote in
ng.com:


"Larry" wrote in message
...
"Charles Momsen" wrote in
news:2a53p5.4mg.17.1 @news.alt.net:

http://www.youtube.com/watch?v=epz6BBZm__0

How utterly great! Thanks!

I didn't notice the retrieval lines that controlled the moment of the
ballast until they hauled it back in. Very ingenious....(c;

If Roger's research vessel had these balls.....he'd be home by
now....(c;

I figured out the retrieval, but how he get the bags out there in the
first place? Help from shore?




If he filled the bags at the hand rail, that would be more than enough
moment to haul the boat over from vertical by winching on the halyards.
Once the boat started over, the moment arm increases because the mast
tilts out, dragging the bags further and further away from the boat,
increasing their torque on the roll to equal the increasing torque in
the other direction from the increasing moment of the keel bulb ballast
going further and further away from centerline. It wouldn't require
anyone off the boat to roll it over. The slack lines from the boat
directly to the bags to retrieve them back towards the boat, gives him
the decreased moment and torque so the bulb ballast will self right it
after the bridge passage (or after you got the damned thing off the
sandbar...(c

Just winch the bags back into the handrail while slackening the halyards
to prevent the mast from hauling them off the water and she'll stand
right back up again.....very nicely.

I'm more interested in their use to recover from groundings than bridge
passages. To have the self-contained power to lay the boat on its side
to unstick the keel from the pluff mud around here and simply back
yourself off the mud, is worth its weight in gold! This is especially
true when Towboat/US tells you then can get to you in 2 hours while
you're WATCHING THE TIDE GO OUT while aground...(c;

I helped a nice 44' cruiser off the mud by using my 175hp jetboat to
pull on the top of his mainmast to starboard, freeing his bulb so he
could power the ketch off the mud with the handrail in the water...as
the tide was going out, by the way. I kept the pressure on as his 6-cyl
Perkins dragged us both out into the channel where I slacked off to self
right it. Worked great...levers and high school physics....



Thanks for the explanation Larry. Makes sense.