Bruce Farr Design ruins Beneteau First reputation
- Thread starter HunterWanderer
- Start date
Sailfree
Well-Known Member
You are right but whats a little exaggeration between friends!!
and even fellow motorcyclists - now I was going round this corner, leaned over and ................rotrax
Well-Known Member
You are right but whats a little exaggeration between friends!!
Keep the shiny side up and the greasy side down..............................
JumbleDuck
Well-Known Member
Is that the one where they keep running a yacht into floating objects, making sure that they always hit them with the stem which is by far the strongest part of any boat? Or did they try running the keel into a solid object at hull speed? I own three stem dinghies, each one of which would easily pass the running-into-floating-things test.
Norman_E
Well-Known Member
Actually the RCD is more about EU protectionism than anything else.
I cannot help the feeling that much of this thread has been taken up by poorly informed criticism of one design and designer. Surely the real issue is that most modern cruising boats and cruiser/racers have bolt on keels. They have advantages in terms of construction cost and boat performance. There are thousands of them, and very few actually fail. Most that fail do so due to gross misuse. If you bash the leading edge of the keel into a rock at full speed you should not expect the boat to have been designed to come away completely unscathed. Yachts are designed to be strong enough to be stood on their keels if dried out on a falling tide. They have enough keel attachment strength to withstand a grounding under sail, but such an event should be followed by an immediate check for any leaks, cracking or other damage. For a fin keel boat to have been grounded more than once and yet not to have been subjected to an expert survey afterwards strikes me as coming into the realm of gross misuse. The CR accident was a tragedy that might have been avoided if the keel attachments had been thoroughly examined after each previous grounding. This tragedy was IMHO as much a failure of care and maintenance as it was of design.
Scotty_Tradewind
Well-Known Member
"There may be trouble ahead"
I clobbered a rock up in Loch Scavaig in 2012.
Small cavity, winter 2013 had a look. Dried it all out, dug a hole and filled it all up again. SIMPLE!
S.
I clobbered a rock up in Loch Scavaig in 2012.
Small cavity, winter 2013 had a look. Dried it all out, dug a hole and filled it all up again. SIMPLE!
S.
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rotrax
Well-Known Member
In my view this has been a usefull debate.
Bruce Farr Designs has not been mentioned directly very often during the debate, Beneteau has.
In you final sentence you agree that in your opinion it was a failure of design as well as poor maintenance.
That is also my opinion.
I am with Scotty Tradewind here-both our boats are heavy and compared to lightweight fin keelers pretty slow.
I dont wish to change mine-and I bet if Scotty did it would not be for a lightweight flyer.
If something you are relying on to stay afloat so you will stay alive and comfortable has the potential to fail and cause loss of your life and the vessel the question must be asked-is it fit for purpose.
The other issue is-highlighted in all of the relevant threads on this-who can fix it PROPERLY.
I asked this question earlier and alluded that some measure of the cost involved would be usefull-but all I have heard is a deafening silence.
We have concluded that Bill with his CGM and pots of WS epoxy is not up to the delicate and technical task-so who is?
Anwers on the back of a ten pound note to win this weeks star prize of a trip across the Atlantic on a 40.7......................
Rattler
Member
What boat can be bought today that does not have this type (Liner) used in the construction?
jonrarit
Well-Known Member
Let me guess Scotty, the one at the entrance to the inner bay ..... that isn't in the right place on the GPS chart .... been there
jr
Norman_E
Well-Known Member
Mostly second hand ones, at least if you are considering volume production boats. Its one reason that I am glad that I own a 1998 boat that was quite well built and has no inner liner inside the hull, but visible glassed in stringers.
Strolls
Well-Known Member
Is that the Jeanneau 45.2 mentioned on your "About Me" page? I think that's a stunning boat.
What are the stringers made of? I thought they dropped wooden stringers before the 45.2.
rotrax
Well-Known Member
Our previous boat was a Gibsea 96.
Just before the serious senior moment that ended with the purchase of our current one my mate Ivor and I fitted a Webasto Thermotop system with radiator central heating. To fit the microbore water distribution pipes he had to bore 20mm holes in the teak stringers across the botton of the hull.
He had worked with wood all his life. He wore out three bits during the job and said the timber was very hard, of very good quality and had been properly seasoned.
They dont make series production boats like that anymore by the sound of it.
Just before the serious senior moment that ended with the purchase of our current one my mate Ivor and I fitted a Webasto Thermotop system with radiator central heating. To fit the microbore water distribution pipes he had to bore 20mm holes in the teak stringers across the botton of the hull.
He had worked with wood all his life. He wore out three bits during the job and said the timber was very hard, of very good quality and had been properly seasoned.
They dont make series production boats like that anymore by the sound of it.
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lw395
Well-Known Member
I'm not sure it's that big a deal whether the floors, stringers and what-have-you are a separate liner moulding, or laid up inside the hull moulding.
It's still in for a hard time if the boat grounds.
Rattler
Member
So it is difficult to buy a production boat for reasonable money after about 1998 that doeswn't have the hull liner?
Yara
Well-Known Member
I have ploughed through all 20 pages of discussion, but it seems that the thrust of the OP's premise has slipped by the wayside.
I think that the Cheeky Rafiki loss will not have any impact on the general market with regard to the Farr design house, as not every owner/buyer is aware that Beneteau have different designers. Certainly there may be negative effects on the Beneteau reputation, but current owners will certainly reject, (as we have seen on these pages), any slurs on the design.
What is pretty clear is that modern designs, with deep, high aspect ratio keels, and lightweight boxy hulls, are not designed to last as long as the old, heavily built models of the past. What is also clear is that any damage to these modern designs is costly, particularly when the matrix style of internal reinforcement is used. The result will be that boats which, compared to the older heavier designs, would have been considered to be in "middle age" will instead be consigned to the scrapheap. In fact, disposal of these boats is going to be an environmental problem, as they are often abandoned by their owners when repairs are worth more than the value of the boat.
As for the failure of the CR hull, I am surprised that the MAIB report focused so much on the adhesion of the matrix to the hull, when clearly there was failure of the keel bolts, and on one side the keel bolt plates sheared right through both hull layers.
Before anybody howls me down, I do have professional engineering qualifications, and what we're looking at requires engineering insight, rather than computer simulation. This is the problem with modern engineers, they think everything can be solved by modelling on a computer.
It is clear that the initial failure was precipitated by failure of some of the bolts themselves, rather than the structure.
The design with cast in keel bolts, and the internal matrix reinforcement, ensures that it is really difficult to correct or observe the classic crevice corrosion which can occur with small amounts of leakage. There is no easy way to detect failing keel bolts, however I would like to see extended threads, and some external framework which would allow tension to be applied to the bolt, and its elastic behaviour observed. This could provide early warning.
Anyway back to the mode of failure, buy yourself a can of sardines with a ring pull opening. The similarity to the situation on CR is striking. When you lift the ring pull, you create a very high shear on a flat pan surface next to a stiff beam edge. This is exactly what the matrix keel bolt design has, with crude steel plates butting up to the beams of the matrix. My analysis is that this occurred as the first stage of major failure after the sheared bolts. The keel itself probably cracked and weakened the pans on the starboard side.
In the next stage, there must have been some form of knockdown, as the ripping of the outer hull would not have occurred in a strip if the keel was falling straight down. Here, the matrix lack of adhesion must've played a part, but at that stage, the game was already over.
Attack my opinion if you may, but I predict that you will see retrofits, and new designs, where instead of crude flat plates bolted to the pans of the matrix, there will be more sophisticated steel saddles to spread the load from the bolts onto the matrix beams. It's not rocket science, is just basic engineering, and it doesn't need a computer model.
I think that the Cheeky Rafiki loss will not have any impact on the general market with regard to the Farr design house, as not every owner/buyer is aware that Beneteau have different designers. Certainly there may be negative effects on the Beneteau reputation, but current owners will certainly reject, (as we have seen on these pages), any slurs on the design.
What is pretty clear is that modern designs, with deep, high aspect ratio keels, and lightweight boxy hulls, are not designed to last as long as the old, heavily built models of the past. What is also clear is that any damage to these modern designs is costly, particularly when the matrix style of internal reinforcement is used. The result will be that boats which, compared to the older heavier designs, would have been considered to be in "middle age" will instead be consigned to the scrapheap. In fact, disposal of these boats is going to be an environmental problem, as they are often abandoned by their owners when repairs are worth more than the value of the boat.
As for the failure of the CR hull, I am surprised that the MAIB report focused so much on the adhesion of the matrix to the hull, when clearly there was failure of the keel bolts, and on one side the keel bolt plates sheared right through both hull layers.
Before anybody howls me down, I do have professional engineering qualifications, and what we're looking at requires engineering insight, rather than computer simulation. This is the problem with modern engineers, they think everything can be solved by modelling on a computer.
It is clear that the initial failure was precipitated by failure of some of the bolts themselves, rather than the structure.
The design with cast in keel bolts, and the internal matrix reinforcement, ensures that it is really difficult to correct or observe the classic crevice corrosion which can occur with small amounts of leakage. There is no easy way to detect failing keel bolts, however I would like to see extended threads, and some external framework which would allow tension to be applied to the bolt, and its elastic behaviour observed. This could provide early warning.
Anyway back to the mode of failure, buy yourself a can of sardines with a ring pull opening. The similarity to the situation on CR is striking. When you lift the ring pull, you create a very high shear on a flat pan surface next to a stiff beam edge. This is exactly what the matrix keel bolt design has, with crude steel plates butting up to the beams of the matrix. My analysis is that this occurred as the first stage of major failure after the sheared bolts. The keel itself probably cracked and weakened the pans on the starboard side.
In the next stage, there must have been some form of knockdown, as the ripping of the outer hull would not have occurred in a strip if the keel was falling straight down. Here, the matrix lack of adhesion must've played a part, but at that stage, the game was already over.
Attack my opinion if you may, but I predict that you will see retrofits, and new designs, where instead of crude flat plates bolted to the pans of the matrix, there will be more sophisticated steel saddles to spread the load from the bolts onto the matrix beams. It's not rocket science, is just basic engineering, and it doesn't need a computer model.
lw395
Well-Known Member
I suspect the above analysis may be deeply flawed.
A reduction in the strength of the hull laminate would cause the loads not to be distributed properly, overloading each keel bolt in turn.
Analysis by analogy to fish cans and a disdain for computers sounds OK in the bar, but probably misses the point.
A reduction in the strength of the hull laminate would cause the loads not to be distributed properly, overloading each keel bolt in turn.
Analysis by analogy to fish cans and a disdain for computers sounds OK in the bar, but probably misses the point.
rotrax
Well-Known Member
I came to a similar conclusion with the obvious tearing marks on the hull-to me that is clear evidence of how it moved.
From that point why it moved is the next question.
Your analasis could well be correct but I suspect we will never know for sure.
A sad event, and one that needs to be taken on board by the industry-and by purchasers who buy and use such craft.
As I said before-leaks can often be managed but sudden inversion because the keel had detatched is a different matter.
From that point why it moved is the next question.
Your analasis could well be correct but I suspect we will never know for sure.
A sad event, and one that needs to be taken on board by the industry-and by purchasers who buy and use such craft.
As I said before-leaks can often be managed but sudden inversion because the keel had detatched is a different matter.
Sailfree
Well-Known Member
Not sure your comments are fair. Tara's comments regarding the effect on Bruce Farr designs is relevant as is his point that older boats might need uneconomic repairs.
The problem with any opinion on the CR is we don't know how severe any of the acknowledged impacts were or how thorough any survey was nor how good any repair attempt was. Yes we know the repair was inadequate but like many structural failures in both buildings and planes it's easy to be clever after the event. In my career I have investigated a number of structural problems and failures and none of them were due to any one factor - usually 3 or more contributing factors.
I note the comment on adding steel saddles and while possible it's one that has to be done with care as alterations like this can cause loads to be redistributed but often to areas inadequate to take the additional load. I have reviewed designs where the addition of a member caused the over stressing of an existing structure that otherwise would have been OK.
None of the failures that I have examined involved any level of stupidity more an understandable error usually combined with other factors and all have left me with a feeling of "there but the grace of God go I. "
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lw395
Well-Known Member
The central point of his post:
""It is clear that the initial failure was precipitated by failure of some of the bolts themselves, rather than the structure.""
That's not actually clear at all is it?
Failure of the bolts would probably be a quick process, not involving a day of leaking.
doug748
Well-Known Member
I am no engineer.
But I guess the internal liner is there to distribute keel loads into the hull and add rigidity. If it becomes detached or damaged it no longer does it's job and the loads go elsewhere. I assume this would be into the keel area which is not designed for the job, the subsequent lack of rigidity allows the structure to move, a bit. Once the compressive strength of the fibre is is exceeded it can move a little more and leak. Once the keel can move freely, at sea, all bets are off. The only question is: will the bolts or the structure fail first? In this case it seems to be a little of both.
Is that daft? Or what.
But I guess the internal liner is there to distribute keel loads into the hull and add rigidity. If it becomes detached or damaged it no longer does it's job and the loads go elsewhere. I assume this would be into the keel area which is not designed for the job, the subsequent lack of rigidity allows the structure to move, a bit. Once the compressive strength of the fibre is is exceeded it can move a little more and leak. Once the keel can move freely, at sea, all bets are off. The only question is: will the bolts or the structure fail first? In this case it seems to be a little of both.
Is that daft? Or what.