Keels and Keels Again!

what happened is probably cowboy designers

 

the nail on the head, lives mean more than trash alloy cups, well to some people they do.

 

If it's a race, never mind the "safety award", or just give all a blue ribbon and tell them not to bother with the dirty part of actually sailing - Special Olympics style sailboat racing! Containers often float just below, or just at, the surface. Tell the thousands of humpbacks eating Alaska out of house and home (20 tons of capelin, sand lance, etc., per animal, per day) that there aren't many. Where are the smart whales? Most of the ones I know are about like a cow and very unlikely to get out of the way (humpback, fin, sei, grey, sperm, right) Minke whales are about the only ones larger than orca smart enough to figure out that a boat hurts before it hits (and I still whacked one of those, once).

 

you must have bumped your head on one of those containers out there floating around

a Humpbacked whale eats about a ton a day maybe two depending on who you talk to
they weigh about 40 tons so the idea that there going to eat half there body weight a day is a bit ludicrous

they pretty much only feed during a specific season and fast for the rest of the year
so on average they eat maybe 500lbs a day
( its actually less than that but the point is moot since Im about to be land blasted for this little tid bit of truth )

they prefer krill but since there is a reduction in ice and an increase in krill fishing there are less krill in the water for them

so we blame em for eating something else

might as well blame them for breathing

they are big stupid and beautiful
probably kinda tasty as well but since we as a species have this lovely habit of eating things into extinction I'll probably never find out

you only have yourself to blame for overfishing

cheers
B

 

I think running those high aspect keels right thru to the decks would not cost much in speed and would make them far stronger. A single hander in a 60 footer is not cramped for interior space. Beefing up the trailing edge attachement point with a huge bulkhead wouldn't cost them interior space that they couldn't live without.
Brent

 

Keels

Stop making so damned many people , and food will not be such an issue.
Brent

 

one clown told a guy I knew that, epoxy is a mechanical fastening,they then glued bullimores keel on,we live in times of great change in wooden boatbuilding where epoxy has replaced skill & make it up as you go along has replaced common sense & responsibility

 

Another one, San Francisco this time:

http://forums.sailinganarchy.com/index.php?showtopic=88193&st=0&#entry2204526

Luckily, no injuries or fatalities.

Cheers,

Earl

 

If Aldens or Herreshoffs keels had fallen off, can you imagine the uproar, what was this keel held on with, chewing gum, when are designers going to take a walk round a cemetery before they design a boat that may kill you, if anyone has the data, there must be a ratio between fractions of a knot gained / crews blood spilt, over the years, if anyone can find this number, we can update it every month & put these design murderers on the spot

 

This is the second J80 to lose a keel recently, hull number 54 tore the keel stub off and others have apparently cracked around the keel stub-hull interface.

Very lucky that they were able to find the handheld vhf in the inverted boat or as they say they would have been dead.

 

As previously posted the builder does what the designer tells him to or another builder gets the job. I suspect the designer finds himself in the same boat, too.

However, as a former engineer I would not be comfortable with bolts stressed in any manner other than they should be, in tension. If the width of the keel-to-hull jointis inadequate to ensure this, the cantilever forces on a keel can still be handled by a through-the-joint structural element more suited to the task.

The traditional way of fastening a keel to a hull has always seemed inadequate to me. the forces that act on a keel have their genesis in the mast and the keel should be fastened at least as securely. As Brent noted, running the keel right through to the deck should not add a great deal of cost: what it does require is a new approach to design and even more, a new approach to assembly. Tradition has it's place all right, and it's on a traditional boat. The technology exists, why don't they use it?

 

I agree....cowboy designers.

 

Keels

It has been suggested that I am wrong to blame builders for keels that are epoxied on and fall off. It has also been suggested that I am wrong to suggest better ways of attaching keels. It has been suggested that anyone with new ideas should remain silent, and let the keels continue to fall off, no questions allowed.
Duhhhh!!!
Brent

 

you are quite right to blame anyone, builder or designer who epoxies a keel on, epoxy is not a mechanical fastening, & please do suggest better ways of attaching keels, we are all here to learn

 

My suggestions for what they're worth are:

1) Extending the keel structure into the hull perhaps through to the deck as already suggested by Brent.
2) Move the keel/hull joint up higher so the joint can be wider and the integrity of the keel itself is not broken at a narrow location.
3) Modify the bolts so the portion that passes through the joint is plain (no screw thread) to eliminate stress concentration at the thread root.
4) Augment the bolts with rods to prevent the cantilever forces from acting on the bolts.
5( Modify the hull and/or keel material to introduce some flexing to absorb impact energy better.
6) Change the handicapping rules to reduce risk and save lives.

These are all very obvious, standard engineering practices. Not being a NA I'm expecting to learn why these cannot be put into practice on racing sailboats. I'm assuming that the most obvious idea, simply making the keel thicker, is ruled out by hydrodynamics and competitiveness.