Concerning the boat that sank during the Vera Cruz race

[Ross]

RichH, The wing struts are never replaced. They are an

intregal part of the wing and designed to endure for the entire service life of the airframe. If keel bolts are subject to such levels of stress as to cause them to fail before the hull into which they are fastened then that is a design flaw. Some components on sailboats are periodically replaced at relatively small expense. Standing rigging has a finite life as does running rigging and the sails. But rudder stocks and keel bolts should be chosen for size and placement and design as to never need periodic replacement. To do so in the pursuit of performance dictates that relative ease of replacement be designed into the structure and replacement components be readily available.

 

[Maine Sail]

Ross..

Keep in mind we have NO idea yet what caused the failure! Considering how many lightweight/displacement racing boats that have been built in the world the keel failure rate is VERY, VERY, VERY low and dwarfed by rig failures!!There are FAR many more spars that fail than keels by a HUGE percentage. Perhaps you should be arguing that standing rigging should last the entire service life?? No?I have been saying for a long while that we WILL see many more keel failures on older boats due to lack of maintenance, constantly wet bilges and crevice corrosion.. That can not be blamed on the engineering however as lack of maintenance/ignorance falls on the back of the owner..Remember there are people out there who claim to know the boat saying it had been previously grounded and repaired so jumping to poor engineering is a stretch at this point..As near as I can tell there have not been many Cape FEar 38's built so it could be an inherent engineering issue but I think we need to wait for the report to start bashing a keel design that is, by the sheer numbers built vs. failures, been proven..

 

[Ross]

MaINESAIL I agree, My contention is that IF keel bolt

fatigue is/was the problem then that is the engineering defect because that can be easily anticipated and prevented. Only an examination of the wreckage will reveal the facts.

 

[GuyT]

Racing boats are different animals

Every ounce is accounted for - therefore every design margin is pushed.Component Failure is part of racing. If it wasnt, they wouldnt be pushing the limits of design weights and they wouldnt be winning.

 

[dpatrick]

EPIRB

That is what I was thinking about. Hand held attached to the PFD of the person at the helm. Hindsight is always 20/20, especially from the easy chair.Our prayers and our condolences go out to the family who is suffering the loss of their loved one. Hopefully more information will be forthcoming that will help others to avoid or be better equipped to handle overwhelming circumstances when that time comes. Sincerely, DPatrick Callahan

 

[Sandy Stone]

Don't think Jboats has all the answers...

I personally know a J-109 owner who returned his boat to the dealer for a factory mod reinforcement to the after end of the keel stub. Also, I think I have seen it mentioned on SA that several J120's have had cracking in the area where the keel stub joins the hull. I personally know of a J120 that very nearly sank in an offshore race when the keel stub began to separate from the hull, but I can't say for sure it was a SCRIMP hull.I am generally not in favor of cored hulls at all, at least not past say five years old.

 

[RichH]

Totally disagree with you Maine ....

A failure is a failure is a failure. A conservative adequate design should NOT/NEVER depend on 'maintenance'. Sure, for a gonads to the wall racing machine that requires a least amount of weight its OK to chintz on 'scantlings'. But a design thats turned over to 'duffers' or 'consumers' is not a place where failure should ever happen. A failure is still a failure; and, forensically it doesnt matter if the failure was ductile, or brittle, or chemical, its still a failure. But we learn from such failures as thats how a design 'evolves'; only the law and lawyers are 'perfect'. ;-)

 

[Ross]

The problems with Stainless steel can be avoided

by using bronze. The problems with rusting iron keels can be eliminated by using lead. The demands of the market place and the need to be able to stay in business has forced many designer to yield to the marketing department and to the accounting department. The differences in cost would be a small percentage of the total cost of a 200,000 dollar boat. But the stock holders and the accountants want the money in the bank.

 

[Bill Roosa]

RichH!!!

I gots me my degree in engineering and we don't never design any thingy to work anywhere near the elastic limit. And then we puts a safety factor (as you noted) of at least 2 so the most that part will ever see in normal (design storm or grounding) conditions is 1/2 of it's elastic limit. Now aluminum has this bad fataguey thing that you have to factor in but I guess the point is you do factor it in. Now if it was one of the new racing boats and they where designing to a SF of 1 and counting on the Captain to control the boat soas to not bust her up then a)they are crazy and gets what they gets and b)just plain askin for trouble as pushin the envelope is what they are a dooin and that means stuff breaks cause you didn't account for all the variables.Someone did not do a repair right or they did something (I can't even imagine) that broke the boat in a way the designer never anticipated.

 

[RichH]

Bill ....

Lemme no who you work fer as I want to 'folloo your folks around' with a personal injery lawyur as a FS=2 is suitabsble only fer static 'non-movin' stuffin's. I wanna take outta a INsurince polisey 'agin ya'. ;-)

 

[Ross]

Since we have such an abundance of it I wonder

how many know what hyperbole is and how to pronounce the word. ;D

 

[John]

Racing boats' keel

I can't remember where, but I recently read an article about a series of events where the keel of a racing boat fell off. The author of the article seemed to feel that the surface area where the keel attaches to the hull is possibly too small in some cases, and this concentrates the load (and the stress) in too small of an area. Is the Cape Fear 38 in this category? Could this have been an issue?

 

[sailortonyb Allied Mis]

I know for fact

that EPIRBS and Life Rafts were required for the race. I can only surmise that everything happened so quickly that the raft and EPIRB were not deployed.I think i mentioned earlier that reporters may be totally ignorant of the topic they are writing about and may have misquoted people. I have had that happen from personal experience.Tony B

 

[Ross]

Jimq26, So good to finally hear from you. Your

posts are so constructive and enlightening.

 

[Maine Sail]

Rich H..

Quote: "A failure is a failure is a failure. A conservative adequate design should NOT/NEVER depend on 'maintenance'."I agree in theory with what you are saying! However, in reality an externally mounted keel sealed with a marine bedding compound is eventually a maintenance item! There are no two ways about it..In a perfect world bedding compounds would stretch 5000% and "NOT/NEVER" fail, but they do, and this is not a perfect world, and keel joints leak and then this becomes a maintenance issue. If ignored the keel bolts WILL become the problem. Many, many owners ignore leaking keel joints, for long periods of time, and this WILL become an issue in years to come as these boats age. This spring I counted no less than seven boats, in my boat yard, that even after a LONG winter on the hard were STILL leaking water from the keel joint this spring? If those keel bolts suffer from crevice corrosion & fail the designer is not to blame the owner is....Should I, as a boat owner, expect an externally mounted keels bedding compound to last for 30, 40 or 50 years? If it eventually fails & leaks should I blame the designer or the manufacturer of the bedding compound?

 

[Ross]

We, as GRP boat owners are spoiled rotten by the

benign neglect that our boats will tolerate. Most of us would, with our maintanence schedule, would distroy a wooden boat in five years. I often think that it would be good if there could be a fitting through which we could inject a sealer in the manner of greasing a bearing with a grease gun. Then when we saw that the joint between the hull and the keel was leaking we could just pump in a fresh glob of sealant and scrape off the excess like wiping off the grease that is pushed out of a bearing.

 

[George]

Hull design

We mfg a product with a cored sandwitch design and the core would only provide global stiffness. The inner skin would have to substantial enough to hold the bolts and would have to extend over a wide enough portion of the hull to distribute the load. I'd be interested in knowing WHAT KIND OF RESIN WAS USED FOR THE HULL CONSTRUCTION. Obviously, resin infused hull would be the most efficient but glass/resin compatibility would also be crucial where you have those kinds of shear forces.

 

[RichH]

Update - the keel is recovered.

First news after the recovery is that the keel and bolting is intact. Apparently the mating area of the hull didnt have sufficient strength (scantlings too low) and the hull attachment /mating area is the probable cause of the failure.... its damn hard to design a proper 'cantilever'. Apparently the original designer had been mouthing off that the yard's execution cut a lot of corners and kind of inferred the low design strength of the mating area.All this info is coming out of the SailAnarchy bulletin board.

 

[sailaway78]

Right about now

I would bet that there are some lawyers ready and waiting. Chomping at the bit. This, as I understand, was a boat owned by Texas A&M. Evidence of a previous grounding with what appears to be some pretty serious damage. A boat yard somewhere who did whatever repairs were done. Or even worse if nothing was done. More than one individual will see some deeeeeeeep pockets there.

 

[Tom S]

It doesn't take a rocket scientist to see the cross section of the keel was thin

Which is what you want if you are designing a go fast race boat.Looking at the pictures that Mainsail posted above you can see that the chord depth of the keel at its attachment point to the hull was very narrow. This makes the physical surface area of the keel to hull attachment very very small. If you are going to do that you really have to put a lot of extra effort in the design of the keel sump area to spread the loads over a greater areaI kind of suspected that the keel bolts didn't fail but rather the scantlings in the keel sump area was just too small and moat probably slightly weakened by the grounding. Like I mentioned before, fast cruiser racing boats like this are built fast but they are not built that robustly. Same thing happened with the Bavaria Match series boats