Cruisers Forum
 


Join CruisersForum Today

Reply
 
Thread Tools Rate Thread Display Modes
Old 01-05-2015, 21:58   #46
Registered User

Join Date: Feb 2014
Location: Niagara Falls
Boat: Westsail 32
Posts: 313
Re: Cheeki Rafiki loss report

Quote:
Originally Posted by SaltyMetals View Post
Oh Dear! Maybe some of you more knowledgeable guys can help. I shared a Beneteau Oceanis 400 (hull number one), 1992 , for many years. This has the same construction using a hull liner. Is the Oceanis 400 the same hull as the First 40.7?

There is a fore-aft crack in the hull liner that is situated about 18" forward of the foot of the pillar support for the mast. The crack itself is about 9" long. No sign of any cracking on the outside when the boat is taken out of the water for her annual scrub.

When i first noticed the crack the boat was only about 1-2 yrs old and Beneteau sent someone to inspect it. All they did was to do a light filler-type repair. They never cut out part of the liner (matrix?) to see if there was any damage underneath. We never grounded the boat apart from mud in a quiet overnight anchorage in a falling tide. I have always thought that this crack is due to flexing in rough seas but mostly this boat has been used for coastal sailing on S coast of UK and NW Spain.Think the worst the boat has ever had was SW F7-8 returning to UK frm the Channel Islands, occasionally SW F5-6 on the nose sailing down to Dartmouth/Plymouth and a N F6 on the nose sailing northwards frm Vigo. The rest of the time she gets treated quite lightly. Never really raced apart from a few Round-The-Island's (that is around the Isle of Wight for those who are strangers to S Coast of UK).

Do you think this rather superficial-looking crack is serious? The keel has never been taken off in her 23-year life.
Here's a light-weight opinion for you. The light filler type repair is not a repair, it is a 'signal coat'. If it cracks, if the crack comes back into it, the hull is working and it may be worth some attention, or even serious.
__________________

__________________
Seymore is offline   Reply With Quote
Old 02-05-2015, 02:52   #47
Registered User
 
Polux's Avatar

Join Date: Nov 2011
Location: Portugal/Med
Boat: Comet 41s
Posts: 4,863
Re: Cheeki Rafiki loss report

Quote:
Originally Posted by Muckle Flugga View Post
Your defense of this design is spirited, and flawed. It iis quite clear (I did read the report meticulously and will give chapter and verse when I have time) that the authors imply that simply heavy SAILING of the boat can cause separation of the matrix from the hull. Grounding likewise, indeed specifically grounding perceived by the skipper to be LIGHT. Your defense based upon some idea that advanced methods of survey MAY reveal the true nature of the problem and have it then fixed (By means which are unspecified and stated to be disputed among expert opinion in this report, and have not been properly clarified by Beneteau) is frankly wasted. You admit that what you call "primitive" means of survey (i.e. those used by the overwhelming majority of actual surveyors in routine checks) are inadequate to detect a major problem. This means that skippers at sea who experience a grounding, albeit light, or else simply a bout of unusually heavy bashing by weather and waves will have zero means of determining whether serious or fatal damage to the hull has been caused.

This to me means absolutely that these boats should never be coded category 0, and are NOT ocean boats, since ocean boats, by definition MUST be able to sustain heavy poundings in remote areas and subsequently carry their crews home through further heavy poundings, without needing the attention of high level electronic devices to determine whether simply going through heavy weather for a long time has caused them to become unseaworthy! What equipment do you recommend that a skipper carries aboard his Beneteau First 40.7 out in the Bundu and the wilds of the world to determine whether his boat is falling apart or not? What do you think said skipper could actually do about it in any case?
I am not defending anything. That boat was not coded category 0 but RCD class A and what I said it is that it clearly meets class A criteria.

The keels don't need to be checked all the time, a bonding does not fail in a sudden way, what I said it was that on this type of boats the bond should be checked regularly (each 5 years or so at first and when the boat is older on a more regularly basis, like the rudder or rig). You don't need to carry with you an electronic device to do that.

The fact that the authors consider that the continued use of the boat on very heavy conditions can lead to the weakening of the bond does not mean that it happens. It is just a possibility that should lead to regular inspections of the bond.

There is out there about 600 First 40.7 and over 800 First 36.7 and from there two boats lost the keel. Both were subjected to groundings, evidence shows that one had the keel bolts not tight and neither of them was subjected to regular proper keel inspections and matrix bond inspections.

I don't know why but you are vastly exaggerating the situation. All that is needed is a regular control of the bonding on boats with a bonded matrix the same way that it is needed a regular control of the laminated when they are laminated to the hull. A good bond can be stronger than a laminate and the situation would not be different if that matrix was laminated to the hull. On a laminate it is more easy to see damage. It all depends on the quality of the bond or on the quality of the laminate. Very expensive boats are using bonding agents to, to fix a matrix to the hull.

Some insist to call a matrix liners. A matrix is a structural reinforcement that is bonded or laminated to the hull (or both things together), a kind of grid that distributes the keel efforts by the hull and that is used practically by all brands on modern boat building.

Yes there is a problem with surveyors, most of them have nor accompanied the evolution of materials and boat construction techniques and are not technological equipped to deal with them. It will be a question of time before they will respond to that. There is a new generation of surveyors that is making a wide use of electronic information devices. They are not only needed on this situation but also very useful in what regards cored hulls and possible delamination of core.
__________________

Polux is offline   Reply With Quote
Old 02-05-2015, 04:35   #48
Registered User
 
Polux's Avatar

Join Date: Nov 2011
Location: Portugal/Med
Boat: Comet 41s
Posts: 4,863
Re: Cheeki Rafiki loss report

Quote:
Originally Posted by neilpride View Post
Termal image i think is what you mean Paulo, is widely used by lots of surveyors, but then what if they spot liner delamination or bonding failure?? and i bet you a cold pack that if they aim the gun in a bunch of production boats fitted with internal grid liners they are going to found lots of suspect spots,, do you learn something from the Yard guys topic or the production boats topic?
No I am talking about infrared devices about ultrasounds:

"Bond line issues. Ultrasound can pick up the transition between skin coat and structural laminate. A clean line will transmit the signal, where a delamination or "never bond" will show a clear interuption on the waveform.

-Secondary bond damage. As noted above, UT can pick up delamination fairly quickly. There's no need to tent off and demolish the interior of the boat in order to determine the extent of damage.
"
Jonathan K Klopman Marine Surveyor

But it seems that the guy from Comet, the surveyor that manages the shipyard where I have the boat and that has patented a device is far ahead. Is device does not show waves that you have to interpreter but an ecography that shows up as an image, like on the human body. With his explanation I was able to see clearly on a cored hull the different components, including the bonding.

Quote:
Originally Posted by neilpride View Post
So in sum,,,the only good place for cheap structural grid liners is a trash bin, and rest in peace, you cant spend 200.000 or 300.000 or whatever sum in a boat supposedly design for ocean sailing work and start to worry about the structure if you ran aground or sail to weather for days ,,, and this is the case with the 40,7, and think about why the earn the nickname of Bendytoys,,...
You keep talking about structural grid liners...but at least now you say that only the cheap ones should go to the trash. That's an improvement even if I don't think it makes much sense to keep referring to the matrix or to the structural grid as liners. In fact they can be made of carbon or steel and have nothing cheap about them. They are used practically in all modern yachts, being them cheap or expensive, low or high quality.

Even regarding using bonding agents to fix them to the hull, it is not a worst system then tabbing them, it can be a better one, it all depends on materials how it is done and the quality of the job. Bonding can be stronger than tabbing.

In what concerns Beneteau and Jeanneau they use that "contre moule" system that allows them to have a superior rigidity without resourcing to cored hulls. Nothing Bendy about the Beneteau First line of yachts. They have have hulls that don't flex much, not a difference for cored hulls. Just another way to have more stronger and less bendy hulls.

Obviously the system has advantage and that's why Beneteau and later Jeanneau use it, being the main costs saving and also not the problems a cored hull can have with water infiltration. Obviously it has also some disadvantages being the bigger one the difficulty in repairing if something goes wrong with the bond or in case of accident.

My main disagreement with you is that you see it as a major problem while I, seeing it as a disadvantage consider that given the 50 000 boats around that use that system, problems are not that frequent.

Another disagreement is that you see boats as being built to last 30 or 40 years and don't see a 20 year old boat as an old one. Maybe that's a cultural difference giving the huge number of old boats around on US but the fact is that here boats are looked like cars are looked now and a 20 year old car is an old one.

Boats are being built now with a life expectancy that relates with design obsolescence and materials are used according with that. I don't believe that production boats are built now to last more than 30 years and I believe that one with more then 15 years should be subjected with a lot more care in what regards maintenance and inspections.

You see all this as a big problem and that leads you to say that old boats were a lot better built, as if it being designed to last more years would be the only factor. I see lightness, stability, power and adequate strength as the main factors for a better built boat and I am not the only one.

Most Europeans (that's the ones that buy more new sailboats) are interested in having a good performance, low maintenance sailboat at a reduced cost. They are not interested in maintaining it for 20 or 30 years, when the maintenance will be costly and the performance low (compared with new boats).

Most Europeans that buy new boats change of sailboat with about the same frequency as they chance cars and that is about each 3 to 5 years so that is what the shipyards are aiming at: maintaining a high level of innovation and boat design development at the better price.

The resale value of a boat is an important factor too so shipyards have to built boats that after 5 years have still a very good value and that means a solid building, good materials and low maintenance but regarding the value of a 20 or 30 year old boat? They cannot care less and I bet that in 20 years most 30 year old boats will have only a residual value and many will be ditched.
Polux is offline   Reply With Quote
Old 02-05-2015, 09:02   #49
Registered User
 
Polux's Avatar

Join Date: Nov 2011
Location: Portugal/Med
Boat: Comet 41s
Posts: 4,863
Re: Cheeki Rafiki loss report

I rememberhaving read this but I did not remember where. That's an article of a reputable surveyor about Cheeki Rafiti keel loss and it is relevant to the thread:

At the moment the loss of the vessel is viewed and has been reported as an unfortunate accident – it wasn’t an accident.

The tragic death of the four crew and loss of the yacht was a result of third party incompetence and negligence and was preventable. Those who were responsible and negligent in the proper care and maintenance of the vessel should be indentified and held accountable to ensure something like this doesn’t happen again. Having recently dealt with a number of claims on behalf London underwriters with similar deficiencies I believe the cause of this tragedy is obvious.

The skipper’s first message reported the yacht was taking on water and requested the owners permission to divert to the Azores; he didn’t report striking anything. It’s apparent that the ingress of water reported by the skipper was experienced and began as the keel bolts lost integrity. The keel bolts were loose and leaking water as evidenced by the rust stains on the apertures which could have resulted from corrosion or metal fatigue; their ultimate failure allowed the keel to separate from the hull. Tightened keel bolts don’t fail, loose ones do. When total failure occurred the keel fell free causing the superficial damage to the hull laminates amidships. The damage, limited to the hull/keel join (amidships), is displayed in the photo below....

the undamaged hull and the undamaged apertures of the forward and aft keel bolts; their clean separation indicates the keel bolts were structurally unsound.

During the 640 nm voyage north the approximately 3500 kg keel was only partially held against the flat hull surface by the defective keel bolts which initially allowed to keel to move with a limited ingress of water. Unknown to the crew because of the sea state and parametric rolling which would have aggravated and accelerated ultimate failure, the keel would have experienced a slow swinging motion before it eventually dropped from the hull.

The inverted hull of the Cheeki Rafiki was found and the photo silently speaks volumes confirming the keel bolt failure that led to the loss of the keel and the rise of the VCG that resulted in the immediate capsizing of the vessel....

This tragedy should not have happened. Through no fault of the crew the Cheeki Rafiki was sent to sea in an unseaworthy condition and those responsible should be held accountable. The families of the victim’s have a right to know of the unseaworthiness and that their loved ones paid a terrible price and died because of the gross negligence of others.

-Capt. E. S. Geary, P.Eng (UK),MRINA, SNAME
Chartered Surveyor (Admiralty & Maritime) – The Royal Institution of Chartered Surveyors
Registered Marine Surveyor – Federation of European Maritime Associations of Surveyors and Consultants
UK-Maritime & Coastguard Agency Code of Compliance Inspector (SCV)
MCA/US Coast Guard/US Maritime Administration Certified ISPS Code Port/Facility, Company & Vessel Security Officer


Beneteau 40.7 | Sailing Anarchy
Polux is offline   Reply With Quote
Old 02-05-2015, 10:09   #50
Registered User
 
transmitterdan's Avatar

Join Date: Oct 2011
Boat: Valiant 42
Posts: 3,132
Re: Cheeki Rafiki loss report

I don't know how he can say someone was negligent or if he knows who it is. But his opinion as to the proximate cause of the failure seems to be based solely on the examination of the picture. The MAIB investigation did a lot more work than that. In terms of the technical reason for keel loss the report and the surveyor seem to agree. Although, the surveyor just thinks it was loose keel bolts. But why were they loose? The MAIB report seems to answer that question. The liner/hull adhesive bond failed allowing the keel side loads to increase dramatically the pressure on hull. The liner is supposed to spread the keel load out. But it has to be bonded to the hull for that to work. As soon as the bond is broken the pressure moves to right where the keel bolts are.

Polux, I admire your defense of the design/build technique but I would be frightened to be in a First 40.7 on big sea many hundreds of miles from protected waters. The bond can in fact fail in an instant. One minute the bond is fine and the next it is not. There is no warning based on what I know about the system. It does not go through a gradual failure and usually there is no way for the crew to detect the failure. Water coming in was the first clue the crew had and they never associated that with the keel bolts.

And I don't read about hundreds of 20 year old boats in Europe going to the fiberglass recycler every year. It is silly to argue that everyone knows these boats only have a 20 year design life. They may "know" it but there are lots of them out there and every year there are hundreds more that come of age. I predict that the small number of keel failures to date will rise dramatically in the next 5 years.

Do B & B tell new buyers that their new 600K Euro boat has a 20 year design life and after that maintenance and upkeep will be cost prohibitive? I doubt it.
__________________
transmitterdan is online now   Reply With Quote
Old 02-05-2015, 10:38   #51
Registered User
 
Exile's Avatar

Join Date: Sep 2010
Location: Land of Disenchantment
Boat: Bristol 47.7
Posts: 2,415
Re: Cheeki Rafiki loss report

When I read the surveyor's report I couldn't help wondering if he would like to amend it now that the MAIB report has been released. It all comes down to simply periodically inspecting/tightening keel bolts? Polux says the integrity of the bond is easy to check, but one needs highly specialized electronic diagnostic tools? There's negligence on the part of whoever maintained CR, but the mfg. remains vague about an inspection/maintenance regimen for this particular system? I'm not an engineer, but there seem to be some incongruities here.

I do find somewhat persuasive that this is uncommonly rare for the number of boats of this particular model/type produced, but how many of those do much more than sit at the dock? OK, so maybe it's still somewhat rare for the actual number which are used hard like CR, but doesn't the govt-regulated "A" rating endorse the mfg.'s claims for this very sort of application? Bolt-on keels are hardly new, and there are plenty of boats with a rep of being well-built where they don't fall off. Like with spade rudders, it probably has less to do with the type of system than the quality of its construction.

As to Europeans' claimed propensity for newer boats, I don't doubt what Polux says, I'm just not sure how it can be affordable given his claims in earlier threads that these types of boats average 50% depreciation in their first 5 years. Maybe this does mean the 20-30 year old ones are simply scrapped -- not because they're no longer seaworthy but because they are no longer worth maintaining in economic terms.
__________________
Exile is online now   Reply With Quote
Old 02-05-2015, 11:19   #52
Registered User

Join Date: Feb 2015
Location: Porto San Rocco, Trieste
Boat: Jeanneau 43ds
Posts: 101
Re: Cheeki Rafiki loss report

On looking at the pics of the up-turned hull of CR it would appear to me that the flexing side to side of the keel will have caused fatigue fractures in the first, second and last bolts. The last one possibly already weakened by corrosion. At that point the centre pairs of bolts would have been flwexing so much that the matrix and hull will have been weak and insufficient to hold the keel on their own after the fracture of the other three bolts.

Polux' contribution seems spot-on as far as I am concerned. The backing plates inside under the bolts should be much wider and spread the load more effectively like the modified pic shown (Bavaria I think). Maybe part of the problem is that the thickness (=width) of the keel at the root where it joins the hull is not normally sufficient to be able to space the pairs of bolts far enough apart to minimise any flexing. Not much any of us can do about that if this is the problem since that is how the boat was originally designed. At least the size of the backing plates can be increased.

I realise i am going a bit off-topic but as for value, I sold my 50% in the Beneteau Oceanis 400 to my friend. She has similar construction with a matrix bonded (somehow) to the hull but having read this interesting thread will be trying to persuade him to have the keel dropped, replace the bolts and increase the size of the backing plates. I have since been looking to purchase a Jeanneau 45DS and I have to tell you that +/-10,000 the values after about 6 yrs (2008/9 model) are about 50% of total cost as new. After 6 yrs i do not think the depreciation is very much as long as the boat is well-looked after. Are there any guys reading this thread who disagree with that?
__________________
SaltyMetals is offline   Reply With Quote
Old 02-05-2015, 11:20   #53
Registered User

Join Date: Jun 2014
Location: San Diego, CA
Boat: Beneteau Oceanis 38
Posts: 563
Re: Cheeki Rafiki loss report

Quote:
Originally Posted by europaflyer View Post
I'm not so sure about the small backing plate theory. If that was the problem, we would have seen the bolts pull through the hull with their plates, leaving holes in way of the bolts. What I see is:

1) first two bolts (single) sheared cleanly
2) next three bolts (double) pulled out through hull with backing plates, removing a substantial amount of both the grid and hull laminate
3) aftermost bolt (single) sheared, possible corrosion



Exactly what caused the initial movement we will never know. The order in which the bolts failed or started to work we won't know. However, the final failure mode seems relatively apparent from this: of the nine bolts, three are sheared and presumably their backing plates are still inside the hull, and six are still attached to the keel, along with the failed laminate section.
It's important to understand that all nine keel bolts were not equally loose.

It's obvious to my admittedly amateur reading of this damage report that SOME of the keel bolts were loose (those that sheared) which led to the keel being held in place only by those that were tight. This reduces the FRP area to which the keel is supported by that percentage. Three were loose, six were tight. The Keel is now supported by 66% of the FRP it's engineered to be held by.

Probably could have gone on that way for decades as a day sailor. In these conditions, the keel needed its full engineering load rating and didn't have it. The FRP to which the keel was attached failed, and the loose bolts sheered suddenly when all the lateral force was transferred suddenly to them.

The backing plates did their job, the matrix did its job, there's no need to speculate anything other than what we already know: Poor maintenance led to a failure in extreme conditions.

There's no hull to which a bolt-on keel can remain attached with an arbitrary number of loose bolts, and the hull is obviously capable of retaining its keel with all bolts tightened, as the number of first 40.7s that still retain their keel in extreme conditions prove.

The numerous advantages of a bolt-on keel (shipping with the keel unstepped, the ability to step various keels of differing types, lengths, and weights, the ability to replace damaged keels completely, and the hydrodynamic efficiencies of fin keels) vastly outweigh the solitary disadvantage of a below-the-waterline attachment point, so they're not going away ever.

This was a failure due to lack of preventative maintenance. A story as old as the sea. Nothing else to see here.

Adding "check keel boat torque" to my annual haul-out for the shipyard. Problem solved.
__________________
mstrebe is offline   Reply With Quote
Old 02-05-2015, 11:41   #54

Cruisers Forum Supporter

Join Date: Apr 2006
Posts: 12,106
Re: Cheeki Rafiki loss report

"5. There is currently no industry-wide guidance on appropriate methods for identifying matrix detachment and conducting repairs,"
Interesting, because in civil engineering there have been in fact some discussions and experiments aimed pretty much precisely at this for some years now. "Smart" structures are being designed with things like fiber optics and wires embedded in them, so that if there are unseen fractures or shifts internally, the signal in the fiber/wire is broken, just the same as a perimeter alarm in a building's windows and doors. And when the system says "signal lost in #217" you KNOW that it is time to get in there and look for damage.


The same thing could "easily" be laid up during hull construction, so that a shifting keel or bending hull caused the fibers to snap and the signal to be lost, letting the owner know that the unseen structural components had now been compromised.


Money? Yes, but surprisingly, less than the crew's bar bill after one race.
__________________
hellosailor is offline   Reply With Quote
Old 02-05-2015, 11:46   #55
Registered User
 
neilpride's Avatar

Join Date: Jul 2009
Location: in the world
Boat: csy 44 tall rig.
Posts: 2,745
Re: Cheeki Rafiki loss report

Paulo obviously dont know what he talking about, is a good google finder, but oh well.


Ok, ultrasound, but there is a problem in the theory, they cant be sure 100% , like i told you 5 post ago, liners dont fitt even with the hull, i got the chance to see a bene hull slice in half with a chainsaw after a hurricane , lots of gaps and voids betwenn the hull and the liner, so i dont understand how the hell your surveyor is going to tell you 100% sure your grid liner is secured bonded to the hull unless he got the data from a perfect similar boat in sound condition, i guess you get the idea no??


I quote a Smart poster from SA.


Given all of these things that could go wrong during manufacture there is not a plethora of keel losses on 40.7s so it then does fall back on to the repair. Unfortunately detection of a fracture in the adhesive would be almost impossible to detect. Ultrasound maybe, but only if you had a base reading of a sound hull to compare to (as FYD said call the designer).

So what to do. should all structural groundings require the boat be totaled? That would make the most economic sense. My guess is CR should have been totaled as the structure could never be fully assessed but the parties involved pulled a "can't you just fix it" and put an unsafe vessel back in the water. This disaster was inevitable from the day the boat was splashed back in the water...


And is not far when he point the boat totaled when you see at the numbers, the bill is a huge one and the result is a unseaworthy boat repaired...


And we have the Farr yacht designers response in short...
the designer responds


Farr Yacht Design President Patrick Shaughnessy took to the SA forums to respond to the MAIB report on the loss of the crew of the Farr-designed Beneteau 40.7 Cheeki Rafiki. .
I just wanted to say to the group here, that we assisted in the MAIB investigation, but were unable to review a draft of the document before it was published. I think there a few inconsistencies in the report, but on the whole it is a well written document.
The report does indicate that prior groundings were repaired in an unknown way. Just to be 100% clear, at FYD we have no knowledge of the Beneteau dealer recommended repair procedure. That by itself is a pretty worrying. Even if that was followed, we don’t necessarily know that it would be sufficient.
We take safety very seriously and will issue an announcement/addendum to the MAIB report with some other considerations. The biggest thing I want to emphasize is, please contact your yacht designer if you have any questions. If you have an incident that potentially caused structural damage, contact your yacht designer. If you have an impending repair contact your yacht designer.
In this particular instance the hull liner laminate (do not call it a matrix), is not a trivial simple laminate. Replacing it with some unknown laminate to similar thickness would not necessarily be adequate. Please ask first. It almost incomprehensible that a repair could be made in a critical area like this without guidance. Please let us help you.
We will be back with more, after we’ve had a chance to fully digest the report. Stand by.




So skip any frutile try out to get a satisfactory answer from Beneteau and contact your yacht designer, the repair procedure is far from Farr offices, cant you believe it..






You say problems are not frequent, i guess you check in situ the thousands of boatyards around the world, expensive for you,,,, but i think nahhh..


Obviously Paulo the system have a huge advantage for the builder, and is to build boats faster and cheaper, the rest is just a big pile of crap in every sense, i dont see any advantage apart from slide a bulkhead in a plastic slot saving working labour or to get a shiny bilge , solid hulls can live with liners or without liners , the other way is the expensive way, and Beneteau is know for faster and cheaper metods of construction, in other words, the other way cant build thousands of hulls without increase the time and cost to finish the hulls.


And i dont say you need a T rex full keel to sail this days, is perfect if you found a reasonable well build it boat , fin and spade rudder, whats wrong with that , nothing..


And regarding most europeans want cheap, and easy to maintain with a certain degree of perfomance boats to sail and recycle after some years , well let me tell you this sounds right but at the same time sounds stupid, could be some EU anal thinking , im sad for you guys....


I say it again , the Fisrt 40,7 have substandar construction, close to the edge to insane , hig aspect fin keel with a narrow foil bolted through a hollow liner, the norm this days...
Cheers.
__________________
neilpride is offline   Reply With Quote
Old 02-05-2015, 11:52   #56
Registered User
 
neilpride's Avatar

Join Date: Jul 2009
Location: in the world
Boat: csy 44 tall rig.
Posts: 2,745
Re: Cheeki Rafiki loss report

Quote:
Originally Posted by mstrebe View Post
It's important to understand that all nine keel bolts were not equally loose.

It's obvious to my admittedly amateur reading of this damage report that SOME of the keel bolts were loose (those that sheared) which led to the keel being held in place only by those that were tight. This reduces the FRP area to which the keel is supported by that percentage. Three were loose, six were tight. The Keel is now supported by 66% of the FRP it's engineered to be held by.

Probably could have gone on that way for decades as a day sailor. In these conditions, the keel needed its full engineering load rating and didn't have it. The FRP to which the keel was attached failed, and the loose bolts sheered suddenly when all the lateral force was transferred suddenly to them.

The backing plates did their job, the matrix did its job, there's no need to speculate anything other than what we already know: Poor maintenance led to a failure in extreme conditions.

There's no hull to which a bolt-on keel can remain attached with an arbitrary number of loose bolts, and the hull is obviously capable of retaining its keel with all bolts tightened, as the number of first 40.7s that still retain their keel in extreme conditions prove.

The numerous advantages of a bolt-on keel (shipping with the keel unstepped, the ability to step various keels of differing types, lengths, and weights, the ability to replace damaged keels completely, and the hydrodynamic efficiencies of fin keels) vastly outweigh the solitary disadvantage of a below-the-waterline attachment point, so they're not going away ever.

This was a failure due to lack of preventative maintenance. A story as old as the sea. Nothing else to see here.

Adding "check keel boat torque" to my annual haul-out for the shipyard. Problem solved.

They mention in the report, the 40,7 keel cant survive without a fwd or aft keel bolt?

2 months ago a Waquiez arrive in the boatyard with 2 missing keel bolts and take one full day to hammer the keel off from the hull...

14 mm aft keel bolt in the 40,7 sounds micky mouse enginering....
__________________
neilpride is offline   Reply With Quote
Old 02-05-2015, 11:59   #57
Registered User
 
Polux's Avatar

Join Date: Nov 2011
Location: Portugal/Med
Boat: Comet 41s
Posts: 4,863
Re: Cheeki Rafiki loss report

Quote:
Originally Posted by transmitterdan View Post
,,,
Polux, I admire your defense of the design/build technique but I would be frightened to be in a First 40.7 on big sea many hundreds of miles from protected waters. The bond can in fact fail in an instant. One minute the bond is fine and the next it is not. There is no warning based on what I know about the system. It does not go through a gradual failure and usually there is no way for the crew to detect the failure. Water coming in was the first clue the crew had and they never associated that with the keel bolts.
...
You get me wrong I am not defending anything just trying to be logical and coherent. The First is far from a boat I would chose in what regards performance cruisers but saying that it is an unsafe boat to go offshore or that a bond can fail from one moment to another makes no sense. Among the First 30.6 and the First 40.7 there are about 1600 boats around, many raced offshore extensively, some circumnavigating and they are not losing their keels.

Regarding what that surveyor said and the analyses that was made by the experts on the hull I think they are complementary. Probably a 3T lose keel and moving around would weaken the bond of the hull with the matrix

Anyway on the report they consider as light grounding what certainly most would not consider as such. I would consider a light grounding touching the bottom softly in a way that no damage result for the boat. As result of what they call a light grounding these repairs had to be made:

‘Remove floor boards and pipe work in way of damaged areas. Cut flanges off six bays, grind back hull, laminate and sides of structural floors. Bond structural floor to hull with GRP, lightly rub down and apply wax gel. Drill off limber holes, refit pipes and floors. Clean vessel. Lift plate washers and re bed’.

They did not took the keel out and use the old hammer test to see what needed to be done. No electronic reads were made to test the solidity of the bond.

Two months later the boat was grounded again damaging the keel:

‘Dress out damage to lead keel. Fill and fair with epoxy filler. Apply epoxy primer and two coats of patch antifouling.’

No evidence that the matrix bond was repaired even if they say that "its matrix had probably been completed during the time the vessel was under repair"

Then 3 years later while racing it grounded again "‘dropped on to the ground’ when in the trough of a wave".

Then again, one year later while training to fast net suffered another "light grounding". On the same year the boat hull was repaired after a collision on the Fastnet.

The boat suffered at least two more groundings (possibly more) on a low entering at the marina (two years before losing the keel).

plus:

2010 – Removal and repair of pulpit following damage and repair to hull starboard
side amidships.
2010 – Cutting out and repair of hull area in way of port aft cradle support, following
some damage when the vessel was lifted out of the water.
2011 – A section of the matrix within the forward cabin was re-attached to the hull
after it was found detached during its coding survey


I would not have any problems in crossing the Atlantic on a first 40.7 but I certainly would not made it on a boat with this history of accidents and groundings

This First 40.7 is certainly not an example regarding what is a "normal" life of a boat. Besides it is not an owner boat but a charter boat and we know what are the priorities of charter companies.

Quote:
Originally Posted by transmitterdan View Post
And I don't read about hundreds of 20 year old boats in Europe going to the fiberglass recycler every year. It is silly to argue that everyone knows these boats only have a 20 year design life. They may "know" it but there are lots of them out there and every year there are hundreds more that come of age. I predict that the small number of keel failures to date will rise dramatically in the next 5 years.
You are citing me wrongly. Please read what I said.

I said that I don't believe that boats made today will have a useful live of 20 years but of 30 years and I did not said now 20 years old boat are being ditched. I said that in 20 years from now boats that would have then 30 years old would have a very reduced value and many will be ditched.

I never said that the boats made now have a 20 year life. The reduced value will have to do with increased maintenance but with obsolescence of design and low sailing performance.

Basically the same reason 30 year old cars are ditched now. You can maintain a 30 or 40 year old car running (as you could maintain an old boat) but the costs and the reduced performance will make that only collectors and very interesting cars will be maintained and not for functional or practical reasons but for cultural reasons.
Polux is offline   Reply With Quote
Old 02-05-2015, 12:24   #58
Registered User
 
Polux's Avatar

Join Date: Nov 2011
Location: Portugal/Med
Boat: Comet 41s
Posts: 4,863
Re: Cheeki Rafiki loss report

Quote:
Originally Posted by Exile View Post
... Polux says the integrity of the bond is easy to check, but one needs highly specialized electronic diagnostic tools? There's negligence on the part of whoever maintained CR, but the mfg. remains vague about an inspection/maintenance regimen for this particular system? I'm not an engineer, but there seem to be some incongruities here.
....
Please can you guys be more careful regarding what you say that I said?

If I said this:
Quote:
Originally Posted by Polux View Post
...
Yes there is a problem with surveyors, most of them have nor accompanied the evolution of materials and boat construction techniques and are not technological equipped to deal with them. It will be a question of time before they will respond to that. There is a new generation of surveyors that is making a wide use of electronic information devices. They are not only needed on this situation but also very useful in what regards cored hulls and possible delamination of core.
Obviously that you will have some difficulty in finding a surveyor that would no go with a hammer on the hull and would find it enough.

If you find a modern surveyor with the right equipment than it would not be a hard task for him. Find a surveyor with modern equipment probably is. I would be looking for surveyors that work directly with yacht brand's and I believe it is a lot easier in Europe than in the US. Those would be more familiarized with modern building techniques and the electronic equipment needed to make trough the hull readings.

It is not me that say that with the right equipment that is a normal task but surveyors that use those technologies:

"Bond line issues. Ultrasound can pick up the transition between skin coat and structural laminate. A clean line will transmit the signal, where a delamination or "never bond" will show a clear interuption on the waveform.
-Secondary bond damage. As noted above, UT can pick up delamination fairly quickly. There's no need to tent off and demolish the interior of the boat in order to determine the extent of damage."


Jonathan K Klopman Marine Surveyor
Polux is offline   Reply With Quote
Old 02-05-2015, 12:36   #59

Cruisers Forum Supporter

Join Date: Apr 2006
Posts: 12,106
Re: Cheeki Rafiki loss report

Couple of years ago, GE was advertising about their radical new medical ultrasound devices, the size of an old Palm PDA and retailing for ten grand, a radical low price point.


So while you can use two fingers (or a tap hammer) to see if a reinforced hull goes "DINK" or "thump", there is in fact a way to literally SEE how the layers are bound together or whether they have separated. Ultrasound, off the shelf.


Now whether a surveyor wants to spend ten grand on a gizmo they'll use twice a year, and ignoring the fact that ultrasound technicians get a l o n g training period before they get licensed to work in the medical field...that's something else again.


But these kinds of joints and structures are NOT impossible to examine. The aviation industry, the oil pipeline and welding industries, they've been doing it long enough so they'll just laugh and point fingers at you if you suggest this is anything new, much less radical.
__________________
hellosailor is offline   Reply With Quote
Old 02-05-2015, 12:53   #60
Registered User
 
transmitterdan's Avatar

Join Date: Oct 2011
Boat: Valiant 42
Posts: 3,132
Re: Cheeki Rafiki loss report

So if the crew has a complete history of every repair and each repair was sanctioned by the designer and inspected by one of a handful of knowledgeable surveyors with the correct (& expensive) tools then they can be confident all is well. Is not a glowing endorsement for the design/build technique IMO.
__________________

__________________
transmitterdan is online now   Reply With Quote
Reply

Thread Tools
Display Modes Rate This Thread
Rate This Thread:

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off


Similar Threads
Thread Thread Starter Forum Replies Last Post
UK yacht Cheeki Rafiki missing in mid-Atlantic 1000 islands General Sailing Forum 517 11-06-2014 16:32
Cheeki Rafiki gmthompson99 Monohull Sailboats 107 30-05-2014 13:37
Restart the search for the missing Cheeki Rafiki crew members. mikethedane General Sailing Forum 0 20-05-2014 08:47


Our Communities

Our communities encompass many different hobbies and interests, but each one is built on friendly, intelligent membership.

» More about our Communities

Automotive Communities

Our Automotive communities encompass many different makes and models. From U.S. domestics to European Saloons.

» More about our Automotive Communities

Marine Communities

Our Marine websites focus on Cruising and Sailing Vessels, including forums and the largest cruising Wiki project on the web today.

» More about our Marine Communities


Copyright 2002- Social Knowledge, LLC All Rights Reserved.

All times are GMT -7. The time now is 06:36.


Google+
Powered by vBulletin® Version 3.8.8 Beta 1
Copyright ©2000 - 2016, vBulletin Solutions, Inc.
Social Knowledge Networks
Powered by vBulletin® Version 3.8.8 Beta 1
Copyright ©2000 - 2016, vBulletin Solutions, Inc.

ShowCase vBulletin Plugins by Drive Thru Online, Inc.