Stability Forum suggestion

[Guillermo]

I suggest the opening of a devoted Stability Forum, as it it a relevant and most important matter in its own. What do you think?

[Jeff]

It might be interesting to brainstorm a bit on the other main categories that could be created to further organize the "boat design" forum as well...

Originally the thought was to keep everything together so it was easy to browse the new topics, but now with 23,162 posts and growing, it might make sense as you suggest to categorize. I find myself using the "new posts" link at the top more and more to see the new posts of the day, so I'm not sure categorization hurts the ability to browse new topics as it once did. And further categorizing would make it much easier and more meaningful to browse by topic later on.

[marshmat]

I've noticed too that the categories are getting a bit too full to browse through easily.... not sure if stability gets enough posts to have a forum to itself, and i'm not sure what splits would work, but I do agree that better-defined categories would make it a lot easier to browse around.

[DanishBagger]

I, for one, would enjoy reading that forum. Stability knowledge is hard to come by (to me, haha), so that way I wouldn't have to glean "nuggets" from threads all over the place.

The only caveat I have is, will a further split in the subjects mean that some subject will have to be narrowed, and thus have to split out over several sub-forums?

As an example would be talks about the glory (or not) of the gaff-rig as oppose to that of the bermuda, and then when talks about the heeling-momentum of both comes in naturally, then it would have to be split, right? Or is that overproblematising things?

[Guillermo]

Just not to open a new thread with this, I suggest Jeff to recall the 'Motorsailers' forum as 'Motorsailers & Trawlers' forum, as suggested by somebody else, I don't remember where.
Cheers.

[kach22i]

Trawlers' forum
How about a "Trolls" forum?:D

[dougfrolich]

My preferences for a good passagemaker (cat0) are:
Light to medium displacement, moderate waterline beam,built with modern techniques so more weight can be used for ballast, bulb keel, rig with low CE, and slightly sweptback spreaders (no runners) moderate flare in topsides, waterballast ( increased power to carry sail, and roll inertia) I belive all these design elements can be combined to produce a safe,stable,and fun boat, a small crew can use for passagemaking.

[Willallison]

I'll add my weight (slim though I am;) ) to the suggestion of a stability forum - it could be further divided into power and sail.....

[yipster]

keep me posted also please, here another stability example i was just reading
replacing a battery bank is no mean task. loading them aboard and stowing them below is hard work and i dont want to poke fun at someones misfortune but i'll never forget what i saw a few years ago. i repeat it here nowbecouse there's a lesson here for all of us. it was spring outfitting time and the yard had just launched this english fellow's sailboat and put iton his mooring. herowed out with his battery and some othergear, came alongside stood up and reached over to pick up the battery. everything was ok until he leaned over to push it up ontothe sailboat. thats when the old physics law about levers took over. the dinghy went out from under him and he went into the water clutching the battery firmly straight to the bottom. soon he emerged clambered onto the sailboat -without the battery offcourse-caught his breath and than watched the wind blow his dinghy toward shore. two guy's waited for it. he waved and hollered thanks for rescuing it for him. than he watched them trow it on their pickup and drive away - never saw them or the dinghy again. or the battery.
from: Minor Brotherton

[Ike]

Is this forum limited tp just saiboats? Reason I asked, is because stability has been a big issue in powerboats as well recently, particularly dynamic stability as opposed to static. A lot of powerboats have a tendency to flop over to one side while on a plane. Of course when that happens, then a lot of other bad things happen. This is particularly evident in what I call condo boats. Narrow for trailerabilty but a tall cabin with a flying bridge. Tall and narrow. Of course it also happened to the Coast Guard's 30 foot surf rescue boat. Something that's not talked about much anymore.

Apparently this has to do with more than just VCG and GM. Hull form particularly in the bow has a lot to do with it to. The Naval Research Lab did a study where they instrumented boats with pressure guages on the bottom and measured the pressure while on a plane. Big surprise. Sometimes the pressures are negative. This results in the area where the negative pressure is being pulled down. This occurs particulary in boats with convex bow sections. This is why the 30 SRB was flopping over and nose diving.

Any thoughts?

[Guillermo]

Well, this is still not a forum, just a thread to find out if there is any interest in the subject. I think we should have a forum about stability in general and people posting threads on whatever kind of boats and stability problems they want to discuss.
We're waiting on Jeff's decission.
Cheers.

[Guillermo]

As this thread has been surnamed '..and seeking input on further categorization' (and not by me), I'm going to make a further suggestion to Jeff:

In my opinion, the Design subforums should be:

- Boatdesign (To treat general matters and mixed discussions)
- Stability (Whatever kind of boats and crafts)
- Propulsion (Whith no subforums at all, as it is a very wide concept with lots of possible subforums. It's confusing to me how it is organized now)
- Planning boats
- Sailboats
- Motorsailers, Trawlers, Trollers, etc.
- Multihulls
- Other craft (Hovers, etc)
- Software.

Maybe it shoud be also good to add two more:
- Interior design
- Equipment (Other than propulsion systems)

What do you think?

[dougfrolich]

Vega: I understand what he was saying, but since the '79 Fastnet wide boats get a bad rap, When wide is not the biggest culprit, but a high CG. As for the negative area in the stability curve, special considerations must be made for wider boats like deck camber and intacked volume of the coach roof that can be counted on in real life conditions, then the negative area can be reduced greatly.

[Jeff]

Thank you very much for the suggestions Guillermo - I think the stability forum is a great idea and plan to create it next week. Still considering if I should further divide powerboats by type and if there are other subcategorizations of design that apply to all boat types that should be their own forums at the same time as the new stability forum is created...

[Guillermo]

Jeff,
Any news on this?

[Guillermo]

Thanks a lot for this stability devoted Forum, Jeff.
Cheers.

[Vega]

Still considering if I should further divide powerboats by type .....


Don't know about motorboats, but regarding sailboats I think multihulls and monohulls shoud be divided.

Cheers