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-   -   What's up with the J80 keels? (http://www.sailnet.com/forums/racing/52993-whats-up-j80-keels.html)

smackdaddy 03-31-2009 11:18 AM

What's up with the J80 keels?
 
A guy lost his keel in the Doublehanded Farrallones race last week in SF. Sounds like he got rolled by a breaker - but another J80 lost its keel recently (completely torn out at the sump).

Anyone know of what appears to be a structural problem here? Or is this just the inherent danger of a bulb keel?

blt2ski 03-31-2009 01:52 PM

From the article on SA, not sure that the actual why these two keels have failed has been said yet. Look at how long it took the CG to figure out/say what happened with the CF38 in Texas. Hopefully it will be known for both at some point in time. Be it J-boats and not building as strong as it should have been, or previous owners grounded, and damage was not fixed, or unknown or unseen until a failure occurred. Fortunately, neither time from what I recall of the other indecent had injuries or deaths. Just shook up folks! Which not that one likes to see shook up folks, better that than injuries or deaths.

While these issues would make me think twice about sailing one, not sure it would be for long. Been many issues with keel failures with rigs and deep bulb keels, like the J80, Giuletta's design, or should I say the design on Giuletta etc. There may be some issues that we as humans have not figured out, planned for with the speeds etc we are driving these boats. Harmonics was something brought up, that may not be figured into the design.

Please note, my thoughts only, not trying to push blame on anyone. I believe generally speaking, J-boats are good products, and worth looking at for a next boat for me any how. There are too many issues with some keels falling off right now. IIRC, the british rag "Yachting World" last year early in the year did a series of articles on some of the keel failures around the world, some why, some questions still un answered etc.

marty

marty

tommays 03-31-2009 02:05 PM

Having looked at the picture of the first J80 with a 2' long X 4' wide piece of bottom missing in ONE piece with PERFECT balse core showing :eek: and the second guys saying they were looking at the bilge pump hanging out the bottom


I have to think all that small flexing is taking its toll over a 15 year peroid of time as both boats are 1993 something

sailingdog 03-31-2009 02:30 PM

This is one reason I have a multihull... No stinking keels to fall off.

tommays 03-31-2009 06:53 PM

http://i565.photobucket.com/albums/s...ys/J80KEEL.jpg

J80 keel porn you should see the pictures of the 105s and 109s :eek:

paulk 03-31-2009 10:31 PM

Getting rolled by a breaker would be like having someone come along with a 20 ton jack to work on your bicycle. Don't be surprised if the frame gets bent a touch. Haven't we all heard how a wave falling on a mile of beach represents more energy than humans have used since we figured out how to light a fire? If four feet of that wave happens to hit my J/80 or my Volvo 70, or my IRC rulebeater the wrong way, chances are something's going to break, regardless of how carefully engineered and built it is. Same thing if you drop it off a hoist. Landing wrong (sideways?) off a 10' wave could be worse, impact-wise, than dropping 5' off a hoist --- and what yard would dare hoist the bottom of your keel 5' off the ground? People underestimate the forces involved and make mistakes about boathandling. Bonds can also weaken and fractures develop. Sailing requires being alert to lots of variables both above and below the waterline, and adjusting to conditions on practically every wave. If it was easy, everyone would do it.

smackdaddy 03-31-2009 11:05 PM

Woah - wait a minute Paul...Bluto told me this stuff WAS easy. Are you telling me it's not?

Bluto you...!

Actually, I thought the "harmonics" theory was kind of interesting. Can these "blade" keels get sideways oscillation going at speed?

Judging by Tom's pic - something whack is going on.

SJ34 04-01-2009 01:25 PM

Where are the stringers?

paulk 04-02-2009 06:08 PM

Boat parts
 
Quote:

Originally Posted by SJ34 (Post 469419)
Where are the stringers?

The floors and stringers are inside the hull, where they belong.

sailingdog 04-02-2009 06:43 PM

You hope that they're inside the hull... they might not be... :)
Quote:

Originally Posted by paulk (Post 470067)
The floors and stringers are inside the hull, where they belong.



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