Gary wrote:
Evan Gatehouse wrote:

Gary wrote:

Evan Gatehouse wrote:

Gary wrote:

I think the stability curves are wrong. If you plug the numbers
into the formulas at US sailing you get a much higher AVS. 110
degrees just doesn't make sense. Not only that but the 460's keel,
although seemingly a little light, is bulbous with the weight quite
low. Something is wrong with that graph.

Gaz


O.k. I'm a polite guy on usenet but you sir are totally wrong and
beginning to **** me off. I'm a naval architect. I do this stuff for
a living.

The stupid calculator only is used to give an ESTIMATE of the AVS.

An inclining experiment establishes the VCG of the boat in a real
world test. It does NOT calculate the AVS. For that you need
software that does take into account the shape of the hull and the
pilothouse. GHS and Autohydro DO that! You could model a foam filled
mast as part of the model if you wished. They are far more trustworthy
and are accepted by USCG for stability calculations of commercail vessels

Gary wrote

Glad I'm getting to you Nav Arch. You do seem to have a grasp on the
above formulae but fail to explain why the boat has an AVS of 110 in the
graph and yet the designer and builder both claim it has a much greater
AVS. In fact the extremely high AVS of the Tayana Vancouver 460 is
discussed in many places around the net. There is no way the AVS is 110.

If you really are a Nav Arch and do this for a living, then do it for
us. Work out the numbers using your program and the data available and
give us your results (which are still only an estimate). As a Nav Arch
it should only take you a couple minutes. Right????

You also earlier said :
"- the ballast/displacement ratio is overly low, meaning a tender boat
with not enough stability "
A Nav Arch would know that initial stability is more than lots of
ballast. A raft has no ballast and is not tender. Wouldn't you say
that you are jumping to conclusions by not taking into account hull form
and the location of the ballast?
In other articles on the net, they also talk of the boat as "stiff" and
"stands up to her sails well".

Your turn.

Gaz
Okay, my turn again. I just googled you and see you may be a Nav Arch.
So why don't you calculate the AVS?

I am quite confident (and I am not a Nav Arch) that the boat will have a
better stability curve than is represented by the one posted.

If it doesn't, and it has an AVS of 110, I wouldn't touch it for
anything but coastal wandering. It will surprise me because the AVS
claims for the 460 are 0 degrees on all the Tayana websites and the
other Harris boats are so seaworthy.

Really though, since we are not doing the buying, this is just an
interesting discussion. No need to get ****ed off.

Gary