Cheeki Rafiki loss report

[TeddyDiver]

Originally Posted by Polux

You mean, you live on a country where buildings are not designed by architects? You mean that sailboats should not been designed by Naval Architects...because they are all trouble

Nope, I mean architects who don't do their job properly. Lack of common sense and professionalism. Alvar Aalto was one of the famous, spectacular buildings with serious issues and he draw the ugliest boat I have ever seen..
NA, totally different trade..

[Polux]

Originally Posted by neilpride

Where , when , how?? i say sailboats produced on the last 20 years from the leading manufacturing company (Beneteau) are defective and design flawed? Twisting words hu?

Not referring only to you:

here are the relevant posts

Originally Posted by Polux

....
This system is used on all Beneteus and Jeanneaus for many years (15? 20?) and the difficulty to make a diagnostic and eventually repair a matrix detachement is not different than on the First 40.7.

Do Minaret means that all those Beneteaus and Jeanneaus have a defect? or a flaw as you put it?

That's a very strange statement if we consider that Beneteaus and Jeanneaus are the leader markets and that nobody would be buying repetitively those boats if they had the maintenance problems you refer at the point of being considered a defect or a flaw.

Originally Posted by minaret

That's exactly what I mean, as I have told you many, many times. ..

and you have said replying to "Do Minaret means that all those Beneteaus and Jeanneaus have a defect? or a flaw as you put it?"

Originally Posted by neilpride

...
Other model got diferent designs and diferent kind of problems, or they share the same isue with the 40,7 in a diferent fashion.
20 years ago things are made diferent, or you want to see a piece of grid liner section from a f456 showing the diference in thicknes and quality compared with today crap,..

So where is the twisting of words? "Other models has different kind of problems or they share the same issue with the 40.7"... It seems to me that Beneteaus that have all those problems and are crap are designed flawed and flawed built boats to someone that views them that way.

It seems that you make a slight distinction regarding older ones that where built the same way, with a bonded integral matrix and the new ones even if I don't understand very well what that has to do the thickness of the liner with the main problem (according to you) that is debonding, the difficulty to repair and to make a diagnostic. Those are the same problems on new and older Beneteaus that use the integral matrix bonded to the hull. I believe that on newer boats you will have better bonding agents and less chance of a debonding and the problem is not the matrix not to be strong enough.

Besides a First 456 is a 33 old design, not a twenty years old one and it was not bonded neither it had an integral matrix. Completely different structure keel system.

[Exile]

Originally Posted by Polux

People buy the boats they choose because they offer the best compromise regarding a given number of different factors.

Safety and seaworthiness is a common nominator for many as interior space decent sailing performance, low maintenance and price.

I think you meant to write DE-nominator but no matter. Not sure I'm understanding you correctly, but I'll give you the benefit of the doubt that you mean that safety & seaworthiness are not one of the "compromises" that people are looking for, at least not a boat with the "A" offshore rating. As far as the other factors you list, I would put PRICE first, at least for most.

There are many that have bought several Beneteaus in a row, remaining faithful to the brand. They are not all inexperienced sailors and some have circumnavigated, some are circumnavigating right now.

No argument here. Many highly competent, capable sailors buying these boats and sailing them far & wide.

As I said there are other brands of similar price and offering similar performances and interior space (Hanse, Bavaria) that don't have this type of integral matrix and there is a reason for Beneteau to be a leader and certainly it is not an excessive number of maintenance problems.

You always seem to forget that integral "matrix" hull liners reduce production costs. Maybe Bene has simply transferred those cost savings over to increasing amenities, for e.g., recognizing it's price & amenities that most people apparently want. So perhaps it's more realistic to conclude that Bene is the industry leader because they simply sell more boats at greater margins. Or maybe you think it's because a typical boat buyer is fully aware of the type of intricacies of keel construction summarized a few posts ago by Neil??

I believe it has to do with an edge on design and modern building techniques that had allowed them to remain competitive in price and offering state of the art designs. The Oceanis 38 is a good example while we wait for the first production boat with a rigid wing sail, that will be coming soon.

Bene's "edge on design and modern building techniques" means they've figured out how to build a boat they can market for all-oceans work at a cheaper price. After all, price is generally the deciding factor in any mass-production market. Nothing wrong with that; on the contrary, it's often a positive. It's just that you often sound like you're simply parroting a sales brochure, and your comments all too often ignore the 800-lb. gorilla in the room, namely whether those cost-savings result in compromises to basic safety & seaworthiness. This is the essence of the debate, not whether any particular party happens to "like" or "dislike" these boats.

[neilpride]

Paulo, you are clear as thick mud...
Im not going to waste my time anymore quoting you.... Thanks..

[Robin3]

Is ittime yet to call it a day y'all and go back to good ol' Hunter bashing? or doncha like bashing the homegrown stuff so much

[Polux]

Originally Posted by Robin3

David Sadler who designed the contessa 26 and 32 was originally a Tank ( as in warfare) designer. There are many here who believe in havning heavily built ( and even heavily armed) tanks as their preferred sailboats judging by the recent trends in threads posting .

Enjoy your season and don't bump any hard bits , No doubt the arguments will all still be around when you return .

Thanks, I will try to do that

Boat Yacht Naval Architecture evolved a lot since those days. On that time few were the ones that had a dedicated formal education on yacht design and I am not even sure if there was Universities with dedicated courses with a focus on yacht design like the ones that exist today.

The design was a more or less thing, basically continuing existing techniques and designs and in the doubt they built heavier and stronger.

I only built a boat, many years ago and the shipyard owner (that produced boats) used to say the boat was so strong and heavy that when I put in the water it would sunk

Today, like in building Architecture, a Naval Architect is a Maestro that leads an highly specialized team. He is the project manager and responsibly for the way the boat program is solved. He develops the design for that program in conjunction with a CFD or VPP specialist, a structures engineer, a technician on composites, a interior design team and sometimes even a designer to sharpen up the quality of the overall design.

A modern production boat, like Beneteaus, is today a highly technological product developed by a highly specialized and differentiated team under the supervision of a NA. A long way from the times of trial and error or overbuilt to be sure that it will not break. This has allowed to lower prices and to produce better sailing boats, faster and with more stability.

I agree that comparing with older ones they are designed to last less time but that had not happen only with boats but with cars, houses and a bit with everything, including computers. The reason is simple, never as now the progress on all those items was so fast and that means the obsolescence arrives sooner. 50 years ago a model from a yacht brand, if a good one, was substituted after 15 or 20 years. Today a model, even if a very good one, is substituted after 5 or 7 years.

That's the difference between the rapidity of evolution on yacht design 50 years ago and now. Obsolescence time is related with that difference in speed that is now 3 times faster than 50 years ago.

[transmitterdan]

Moore's law does not apply to sailboats....thank the deities of the sea for that. If you want fast paced improvement in design resulting in lower and lower costs for throwaway products buy a smart phone or tablet but not a sailing yacht.

[leftbrainstuff]

Originally Posted by minaret

Agree. Encapsulated keels come with their own set of problems. Lead bolt on wins hands down. Cast iron is for suckers who don't know any better.

How so?

How many encapsulated keels have failed catastrophically?

We're not talking about degradation of old wet boats, we're discussing catastrophic failures of a design, the bolt on keel, which concentrates stress.

The cheeky rafiki was a well maintained racer cruiser. The engineering lessons from this failure is twofold:

1) concentration of stress in mission or safety critical systems, the hull, rarely fail gracefully
2) risk management must always consider the detectability and not just the severence or probability. Its why a FMECA and not just FMEA must always include consideration of detectability.

Sent from my SM-N900T using Cruisers Sailing Forum mobile app

[Polux]

Originally Posted by leftbrainstuff

...
The cheeky rafiki was a well maintained racer cruiser. ...

That contradicts the analyses a reputable surveyor has made (he talked about negligence) and contradicts also what the MAIB report says about Cheeki Rafiki maintenance. Why do you say that? Based on what?

[Exile]

Originally Posted by Polux

That contradicts the analyses a reputable surveyor has made (he talked about negligence) and contradicts also what the MAIB report says about Cheeki Rafiki maintenance. Why do you say that? Based on what?

One more time, Polux -- the surveyor you quoted may have been reputable, but he made his apparently informal comments shortly after the incident occurred, and long before the MAIB report was issued. Subsequent to this surveyor's "analysis," five other 40.7's were physically inspected (randomly or not) & also showed signs of liner detachment consistent with groundings, and a couple of them with mere slamming. YOU can surmise that groundings also contributed to fwd keel detachments that the report attributed to mere slammings, but this is not what the report said. This is in addition to "much" other anecdotal evidence of 40.7's that showed detachments due to grounding and slamming. So whether it was groundings, poor maintenance, a design defect, or an Act of God on Cheeki Rafiki, it was an occurrence consistent with what's happened on the same model of boats, and is in accord with the opinions concerning weak construction from boat maintenance professionals. You're entitled to your opinion about whether this amounts to a pattern, but please refrain from distorting the underlying facts as outlined in the report.

Which reminds me, the report stated that the CR crew dove on the boat twice in Antigua in the week preceding their tragic passage. The report further stated this was for the purpose of cleaning the bottom and also inspecting the keel & rudder, etc., and that nothing problematic was reported. I don't think anyone knows if the keel bolts were ever inspected before or during their trip home, but we also don't know if this would have revealed whether something was awry. We also know that one of CR's last communications indicated that the water ingress had increased significantly after hitting a wave really hard, and that there was no evidence of hitting a submerged object. This doesn't necessarily mean that the prior groundings & repairs didn't precipitate this, but it does suggest that slamming alone can be the ultimate straw that breaks the camel's back.

So much for your "theory" that these keel detachments only occur over long periods of time, and cannot happen suddenly and w/o warning. According to the report, they are also difficult to detect and, according to the five GRP techs that were consulted, a skilled tech using the "hammer & tap" method remains the most viable way of inspection. This, btw, is also exactly what Neil & Minaret have been trying to tell you. Your youTube video of a guy apparently using some sort of ultrasound device -- or "echography" as you call it -- on a hollow, carbon fiber MAST notwithstanding.

[Polux]

Originally Posted by Exile

One more time, Polux -- the surveyor you quoted may have been reputable, but he made his apparently informal comments shortly after the incident occurred, and long before the MAIB report was issued. Subsequent to this surveyor's "analysis," five other 40.7's were physically inspected (randomly or not) & also showed signs of liner detachment consistent with groundings, ....

What has to do other boats with the statement that was made regarding the Cheeki Rafiki being in a good state of maintenance? That surveyor have looked at the same photos that were used on the MAIB report and clearly detected non tight keel bolts and cleared stated that therefore the boat had been negligently maintained.

The MAIB report confirms the continuous negligent maintenance, stating that the boat was previously presented to be inspected to be coded with a matrix detachment that was clearly identified by the Coding inspectors and had not been repaired.

You seem to like to mix things. That is about the state of maintenance of one precise sailboat that lost the keel that I was talking about, the one that was grounded 5 times. That one was a charter boat and was not on a good maintenance condition as stated by a surveyor (that call it negligent) and stated previously also by the surveyors that made the coding inspection.

[Exile]

Originally Posted by Polux

What has to do other boats with the statement that was made regarding the Cheeki Rafiki being in a good state of maintenance? That surveyor have looked at the same photos that were used on the MAIB report and clearly detected non tight keel bolts and cleared stated that therefore the boat had been negligently maintained.

The MAIB report confirms the continuous negligent maintenance, stating that the boat was previously presented to be inspected to be coded with a matrix detachment that was clearly identified by the Coding inspectors and had not been repaired.

You seem to like to mix things. That is about the state of maintenance of one precise sailboat that lost the keel that I was talking about, the one that was grounded 5 times. That one was a charter boat and was not on a good maintenance condition as stated by a surveyor (that call it negligent) and stated previously also by the surveyors that made the coding inspection.

Well Polux, since you're taking off sailing soon & maybe pressed for time, perhaps you should quickly review what you wrote early on in post #6. Not only did you properly attribute the MAIB report as being the most important document, but you explicitly referred to the problem, despite all the 1000's of other well-functioning boats out there, as a potential defect.

In an all out effort to meet your standards of "precision," here is what you wrote in post #6, quoted verbatim:

The real important document is this one:

https://assets.digital.cabinet-offic...ort_8_2015.pdf

Some conclusions:

1. It is difficult to readily identify areas where a matrix detachment has occurred in GRP yachts manufactured with a matrix bonded to the hull. This is especially the case where the keel is not removed prior to inspection and where floors have been layed up between frames.

2. It is possible that some of Cheeki Rafiki’s reported ‘light’ groundings could have significantly affected the integrity of the matrix attachment in way of the keel.

3. A skipper’s perception that the force of a particular grounding is insufficient to raise concern does not necessarily mean that significant damage has not occurred to the keel and/or the vessel’s structure.

4. False indications may be obtained when hammer testing to identify matrix detachment, particularly in the area around the keel washer plates, owing to the clamping effect of the keel bolts and where the rig has been tensioned to cause compression of the matrix/hull attachment.

5. There is currently no industry-wide guidance on appropriate methods for identifying matrix detachment and conducting repairs, or on the circumstances that would necessitate keel removal.

6. Matrix detachment had previously occurred in Cheeki Rafiki, probably in bays immediately either side of the bays where the keel was bolted to the hull. It is therefore possible that detachment had also occurred in way of the keel but had not been detected because of the clamping effect of the keel bolts.

7. Had Cheeki Rafiki’s structure where the keel was attached to the hull been weakened as a consequence of previous groundings, this might have allowed movement of the keel due to transverse loading in the prevailing sea state, resulting in its becoming detached from the hull. It is also possible that the keel bolts had deteriorated.
...

1. It is possible for matrix detachment to occur in GRP yachts manufactured with a matrix bonded to the hull, resulting in loss of structural strength. The probability of this occurring will increase with more frequent and harder yacht usage.....

1. The practice of allowing a vessel to ground during training and examinations has the potential for candidates to underestimate the likely consequences of grounding. ...

1. The Beneteau First 40.7 keel washer plates would have needed to be 3mm thicker and 3mm wider for the design, incorporating only one 14mm bolt, to fully meet ISO 12215-9, today’s harmonised ISO standard for keel design and attachment.

The highlighted parts are the ones that seem more relevant to me.

Neil had talked a lot (on other threads) about the difficulty in assessing damage in a yacht with a matrix bonded to the hull. That's the case with Beneteaus and Jeanneaus. .

The system works as it is proven by the 50 or 60 000 Jeanneaus and Beneteaus out there without problems but a building defect can remain hidden and it is very dificult to acess if there are damage or not after a grounding.

I couldn't agree more with how you characterized & highlighted the report's conclusions then, but you may want to ask yourself why you're singing a different tune now. In particular, there is no mention by you in post #6 or anything I can find in the report which concurs with your "reputable surveyor's" premature opinions about prior "negligent maintenance" playing such a large role, if any. This one surveyor had no connection to the MAIB inspectors or that process as far as I know, and was obviously making an assumption w/o further investigation after merely viewing the photo of the upturned hull. Not necessarily an unreasonable assumption for a layman, mind you, but a nevertheless speculative one, especially given its timing. Representing it as otherwise is misleading whether you wish to confine the discussion only to the specific case of CR, and certainly to what implications it may have to other boats out there which share features of CR's design & construction. Happy sailing.

[Exile]

Originally Posted by leftbrainstuff

How many encapsulated keels have failed catastrophically?

I was planning on asking Minaret this myself, but then thought I may not wanna hear the answer. I would hazard a guess that not many fall off catastrophically, but it would be useful to know what sorts of problems one can or should anticipate. I suspect to hear about fewer problems with lead vs. iron, but maybe Minaret will respond. Also curious about his opinion that (properly) bolted-on lead is best.

What seems most relevant to the thread discussion, of course, is that properly bolted-on keel structures seem to enjoy a good reputation generally, a fact which, if true, only makes the CR incident that much more bothersome. IMHO, that is . . . .

[donradcliffe]

Originally Posted by Polux

Besides a First 456 is a 33 old design, not a twenty years old one and it was not bonded neither it had an integral matrix. Completely different structure keel system.

The First 456 does have an internal matrix, but it is tabbed onto the hull and separation is pretty detectable. On one hand the F456 layup is probably 25 mm thick at the keel, bu ton the other hand the factory keel bolts are only backed with simple fender washers--not nearly as substantial as in the 40.7. I know of one 456 which had keel problems (grounding in a hurricane), and it was repaired with much more substantial backing plates.

I've been trying to figure out how the cheeky Rafiki keel attachment failed so suddenly. We will probably never know for sure, but the MAIB report seems to point toward the shearing failure of the two forward and one aft centerline keel bolts. From the rust stains, it may have been that the aft keel bolt was corroded and was the first to fail--perhaps well before the incident. This put more load on the forward centerline bolts leading to their fatigue failure. AFTER the 3 bolts had sheared, the remaining structure was not up to the task, as the remaining keel bolts and backing plates tore through the laminate structure.

There is a lot of MAIB discussion of groundings and the detachment of the stiffening matrix from the hull. However, it is not at all clear to me how that detachment lead to the failure of the centerline keel boats, especially as the keel boats clamp the matrix and hull together in that area.

A grounding at hull speed is going to put more stress on the forward keel boats, while the aft bolt is going to have less stress, or even be in compression. Yet it was the aft bolt which showed signs of corrosion, probably due to the failure of the sealant around the bolt in some much earlier incident.

A contributing cause to the sudden detachment was the skipper's decision to keep driving the boat hard after the water started coming in. With 20-20 hindsight, if he had cut the sail area and run with the wind and sea, he might have had enough time to declare a Mayday and get rescued.

After seeing the aftermath of a hard grounding in a modern Bene I think the builder's shortcut of gluing the matrix to the hull results in a 'throwaway' boat, as the repair costs came close to the value of a 6 month-old boat.

[Polux]

Originally Posted by Exile

Well Polux, since you're taking off sailing soon & maybe pressed for time, perhaps you should quickly review what you wrote early on in post #6. Not only did you properly attribute the MAIB report as being the most important document, but you explicitly referred to the problem, despite all the 1000's of other well-functioning boats out there, as a potential defect.

In an all out effort to meet your standards of "precision," here is what you wrote in post #6, quoted verbatim:

The real important document is this one:

https://assets.digital.cabinet-offic...ort_8_2015.pdf

Some conclusions:

1. It is difficult to readily identify areas where a matrix detachment has occurred in GRP yachts manufactured with a matrix bonded to the hull. This is especially the case where the keel is not removed prior to inspection and where floors have been layed up between frames.

2. It is possible that some of Cheeki Rafiki’s reported ‘light’ groundings could have significantly affected the integrity of the matrix attachment in way of the keel.

3. A skipper’s perception that the force of a particular grounding is insufficient to raise concern does not necessarily mean that significant damage has not occurred to the keel and/or the vessel’s structure.

4. False indications may be obtained when hammer testing to identify matrix detachment, particularly in the area around the keel washer plates, owing to the clamping effect of the keel bolts and where the rig has been tensioned to cause compression of the matrix/hull attachment.

5. There is currently no industry-wide guidance on appropriate methods for identifying matrix detachment and conducting repairs, or on the circumstances that would necessitate keel removal.

6. Matrix detachment had previously occurred in Cheeki Rafiki, probably in bays immediately either side of the bays where the keel was bolted to the hull. It is therefore possible that detachment had also occurred in way of the keel but had not been detected because of the clamping effect of the keel bolts.

7. Had Cheeki Rafiki’s structure where the keel was attached to the hull been weakened as a consequence of previous groundings, this might have allowed movement of the keel due to transverse loading in the prevailing sea state, resulting in its becoming detached from the hull. It is also possible that the keel bolts had deteriorated.
...

1. It is possible for matrix detachment to occur in GRP yachts manufactured with a matrix bonded to the hull, resulting in loss of structural strength. The probability of this occurring will increase with more frequent and harder yacht usage.....

1. The practice of allowing a vessel to ground during training and examinations has the potential for candidates to underestimate the likely consequences of grounding. ...

1. The Beneteau First 40.7 keel washer plates would have needed to be 3mm thicker and 3mm wider for the design, incorporating only one 14mm bolt, to fully meet ISO 12215-9, today’s harmonised ISO standard for keel design and attachment.

The highlighted parts are the ones that seem more relevant to me.

Neil had talked a lot (on other threads) about the difficulty in assessing damage in a yacht with a matrix bonded to the hull. That's the case with Beneteaus and Jeanneaus. .

The system works as it is proven by the 50 or 60 000 Jeanneaus and Beneteaus out there without problems but a building defect can remain hidden and it is very dificult to acess if there are damage or not after a grounding.

I couldn't agree more with how you characterized & highlighted the report's conclusions then, but you may want to ask yourself why you're singing a different tune now. In particular, there is no mention by you in post #6 or anything I can find in the report which concurs with your "reputable surveyor's" premature opinions about prior "negligent maintenance" playing such a large role, if any. This one surveyor had no connection to the MAIB inspectors or that process as far as I know, and was obviously making an assumption w/o further investigation after merely viewing the photo of the upturned hull. Not necessarily an unreasonable assumption for a layman, mind you, but a nevertheless speculative one, especially given its timing. Representing it as otherwise is misleading whether you wish to confine the discussion only to the specific case of CR, and certainly to what implications it may have to other boats out there which share features of CR's design & construction. Happy sailing.

I don't understand what you want to highlight about the boat maintenance. The conclusions state that there is a need of a protocol for inspections and repairs and that's true but on the report it is said also that the boat grounded 5 times, that there is no reports of inspections on some of those groundings and say that the surveyors, when the boat was officially inspected for commercial coding found a matrix detachement and that the boat was not surveyed again (as it should) to see if it was repaired because they took a loophole, coding the boat very low, avoiding further inspections. I wonder why?

All that is on the report.

There is also the opinion of another surveyor that stated clearly that the boat was not on a seaworthy condition (keel bolts lose) and that the maintenance was negligent.

Do you mind to explain to me why after all this evidence do you think that the boat was in an adequate state of maintenance?

That is what we are discussing. Someone stated that the boat was well maintained and that was to that that I replied saying that it was not and explaining why, not with my opinion but with the opinion of a surveyor and with facts that are on the report.