Cynthia Woods verdict

[Peter Ross]

Do you know what model that is? Everything looks the same as mine except on major thing...that stub is supposed to be 2' deep. Did they fill in the stub to add weight to the keel or was it made that way?

I still say that the glass broke on Cynthia Woods because the keel wasn't bolted on tight enough. Loose bolts will do that. In this case, it definately wasn't the bolts which is scary but it doesn't say anything about the backing plates not being big enough which is my point.

Franklin,
I think that keel is filled with rain water, it's tough to say how deep the sump is.
Since your keel is sump attatched it is not similar in construction to CW's. The CF 38's are canoe bottom boats with no sump at all.

The bolts on CW were still torqued, not loose.

 

[Rick D]

Ah, Main...

Are you personally familiar with that Hunter keel you used to illustrate laminate failure? Is there a link to the analysis? The bulk of that looks cut rather than torn. I would hate to hold this up as an example of keel failure w/o a fuller explanation.

 

[Ross]

We were discussing on another thread some time ago the strength of laminate repairs and IIRC the numbers for tensile strength of fiberglass/ resin bonds was less than 400 PSI. The contact area as shown in the picture is as minimal as can be achieved between two assemblys. Just spreading the load over a larger area would have removed this assembly from ever being discussed. Fiberglass unidirectional cloth is good for about 600 pounds per linear inch, lap it six inches onto the hull and six inches onto the keel and even with poor quality work it would be enough. Increase it to several plies and it never becomes a problem.

 

[Franklin]

Are you personally familiar with that Hunter keel you used to illustrate laminate failure? Is there a link to the analysis? The bulk of that looks cut rather than torn. I would hate to hold this up as an example of keel failure w/o a fuller explanation.

Not only does it look cut, but if it weren't, I'd would have to believe the boat sunk and it wouldn't look like it does. I'd also believe the keel would still be down there on the bottom because who's going to try to lift 5,000+ lbs off the sea floor when the boat would be deamed salvaged.

 

[Franklin]

Franklin,
I think that keel is filled with rain water, it's tough to say how deep the sump is.
Since your keel is sump attatched it is not similar in construction to CW's. The CF 38's are canoe bottom boats with no sump at all.

The bolts on CW were still torqued, not loose.

If it's filled with rain water, then how much? You can't tell me that the keel bolts are 2' longer then need be. No, I think there is some custmization going on here. I bet they cut the keel off and decided to add more weight to it and then re-attach it.

 

[Peter Ross]

If it's filled with rain water, then how much? You can't tell me that the keel bolts are 2' longer then need be. No, I think there is some custmization going on here. I bet they cut the keel off and decided to add more weight to it and then re-attach it.

Honestly I have no idea, I simply noted the keel in the photo seems to have water in it. No opinions on that boat or it's condition before and after it's keel removal. I came here to discuss the CF38, which I am extremely familiar with. You asked if there was a way to determine hull thickness without removing your keel, I suggest you call Hunter and ask them directly.

 

[Maine Sail]

If it's filled with rain water, then how much? You can't tell me that the keel bolts are 2' longer then need be. No, I think there is some custmization going on here. I bet they cut the keel off and decided to add more weight to it and then re-attach it.

Story was, as I read it, boat found the bottom, partially ripped keel off, boat filled with water was salvaged and these photos were shot. I have seen the stubs on these Hunter keels as they ship some models up this way less keel and then it is dealer attached. No one in their right mind cuts the keel stub/sump out of a boat to remove a keel. You remove the keel nuts, backing plates and cut away the 5200 and drop the keel separating it at the stub to keel joint. There is torn fiberglass still hanging from the bottom of the hull and at the leading edge of the keel. The story was that when the boat came out of the water the keel was still partially attached then cut the rest of the way off..

Again my original pont was that the backing plates did their job but the glass work failed like the CW.

The moral of the story in both cases is don't hit the bottom!

 

[gablent1]

Much has been said about this catostrophic failure that happened, and much of it is correct. However, I havn't seen much said in regards to the structural glass content, original or on the repair that was supposedly done.
I can tell you this, when fiberglass is oriented in an axis that is sideways to the loads that it supports, it yields very fast. Take a look at the picture that shows the fiberglass that is sticking out between the warped stainless backing plate and the keel. In this picture you will notice fibers of the glass that are oriented in the 0 degree axis ( for and aft ) and fibers that are oriented in the 90 degree axis ( athwartships or side to side ). The mere orientation/ or use of this 0/90 fiberglass could cause failure as the loads in the keel are mainly side to side until a grounding. When groundings occur you then depend on the keel floors ( if they exist ) to further take the grounding loads.
It's sortof like this, hold your 4 fingers together on your right hand straight out tightly and horizontal, no thumb. Now try and bend those fingers with your left hand up and down. It's hard right!
Now, hold the right hand with the same orientation only this time take 1 finger ( lets say index finger ) of your left hand, and poke it between any 2 fingers of your right hand. Hold your right hand fingers as tight as you want and it is still easy right!
Well your fingers represent the orientation of the fiberglass. So, in this case no matter how many layers of fiberglass were used, if they were all 0-90 orientation, then you could say that they used only half the glass that they were supposed to, because half of it was oriented in the wrong direction...or if there was 3/8" of 0-90 fiberglass existing between the backing plate and the keel, only 3/16" was oriented in a direction of full use.
ABS has much more to say as to the scantling thicknesses and supports. Someone has mentioned this earlier and this shouldn't be taken lightly.
I could say lots in regards to the structure but respect for a family that is now missing a beloved family member keeps me from doing just that.
I will say this in regards to this catastrophic failure. This was preventable for Soooooo many reasons. I did not know Roger Stone but he is obviously a HERO that saved the lives of an ill-fated crew. Bless his soul and the souls of the Stone family/friends and the crew that sailed with him on this final voyage.
Sincerely, MG