“Cheeki Rafiki” Report Misses An Opportunity to Make Boats Safer

MAIBInvReport_8_2015-1_250I would be the first to commend the authors of the report on their diligence in analyzing the capsize of the Beneteau First 40.7 Cheeki Rafiki and the tragic loss of four lives.

Having said that I believe said report failed the offshore sailing community in its recommendations.

Let’s summarize what I concluded from the report and then look at the steps I believe that we should take to at least reduce the chances of another sudden keel loss tragedy.

Not The Builder’s Fault

The designer and builder of Cheeki Rafiki were at least reasonably diligent…when measured against prevailing standards. That last clause is in bold for a reason that will become apparent later.

…Farr Yacht Design Ltd was guided by the existing American Bureau of Shipping (ABS) classification society rules when completing this particular area of its design and associated calculations.

All materials used in the construction process were tested in Beneteau’s laboratory prior to entering the manufacturing process. These included all adhesives, resins, glass fibres and metals.

(All the quotes, unless otherwise attributed, are from the report.)

The point we need to understand here is that builders like Beneteau operate in a very price competitive market and therefore we can’t reasonably expect that they will spend money out of their profit margin to increase the strength of their boats over and above the minimum industry standards, both prevailing by current custom and required by legislation—beating on builders like Beneteau is not going to help.

As an aside, but an important one, readers with a technical bent may wish to also read the Annexes to the report and particularly the part prepared by the Wolfson Unit, starting on Page 13, which includes drawings of the first 40.7 keel attachment area.

Said Wolfson report does state that while Cheeki Rafiki complied with ABS standards the boat would not have passed the newer ISO 12215-9.

Having said that, in my opinion the differences between the two standards are not material, as least when applied to my conclusions below.

Not The Crew’s Fault

It is clear from the report, at least to me, that the crew were competent, well trained and probably performed well.

Those who have second guessed this crew and suggest that they should have done more to find the leak have simply not been offshore in a small sailboat in the kind of conditions prevailing before the accident.

In my opinion, Cheeki Rafiki failed the crew, not the other way around.

Not The Weather

MAIBInvReport_8_2015 Grib

There is no question that the weather at the time of the keel failure was nasty and that the crew and shore personnel were being aggressive in their routing, but even so the boat encountered nothing worse than any boat crossing the North Atlantic can easily be subjected to and should be ready for.

ISO 12215-9 defines Design Category A as: ‘category of craft considered suitable to operate in seas with significant wave heights above 4m and wind speeds in excess of Beaufort Force 8, but excluding abnormal conditions such as hurricanes.

With reference to the hindcast weather data for 0300 on 16 May 2014, it is concluded that Cheeki Rafiki was operating within its design category criteria at the time of its loss.

Not The Safety Equipment

Sure, some of the safety equipment on Cheeki Rafiki was not the very best available or installed in the very best way. The report spends a lot of pages on this (rightly so), but really, based on my experience, said equipment and installation wasn’t that bad either.

And the point we should not lose sight of is, that if a boat experiences sudden keel failure and suddenly inverts far from help in heavy weather, things are unlikely to end well, regardless of safety equipment carried.

The Big Question

Overturned hull of the "Cheeki Rafiki", U.S. Navy photo.
Overturned hull of the “Cheeki Rafiki”, U.S. Navy photo.

So, what happened? Why did these four men die? Well the report does a great job of explaining that. To really understand the contributing factors you need to read the whole thing, but here’s a summary:

Grounding Damaged

Cheeki Rafiki over her life, like any sail training boat, was treated hard with many miles and an indeterminate number of groundings.

Cheeki Rafiki grounded twice in 2007. After each grounding, it was inspected and repaired. The yacht had at least four further groundings; all were described as ‘light’.

These groundings (definitely) and cycle loading while sailing many miles (probably) weakened the keel to hull joint to the point where it failed.

Difficult To Detect

Worse still, the report highlights that because of the type of structure used to take the keel forces, it is difficult to determine by inspection whether or not the keel structure is safe after a grounding.

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.

Inadequate Repair

The keel support structure on Cheeki Rafiki was repaired twice after groundings but it seems likely (since the keel fell off) that repair was not adequate and did not return the structure to original strength.

Further, in my opinion, if a boat has experienced a structural failure due to grounding, not once but twice, as Cheeki Rafiki had, repairs should have increased the strength of the boat over and above original build.

The Fundamental Problem

MAIBInvReport_8_2015keel
Typical Beneteau First 40.7 keel bolt arrangement (not Cheeki Rafiki)

Easy To Damage

The loss of Cheeki Rafiki is just the tip of the iceberg. Several of her sister ships have suffered from the same problems. The fundamental issue seems to be that these boats rely on a structural liner to take the loads of the keel. The matrix—as it is called throughout the report—is fabricated outside of the boat and then glued in.

Now I understand that modern adhesives are incredibly strong, but clearly something is wrong. Over and over again we see boats with this construction technique suffer separation of the matrix from the hull in a grounding as well as damage to the laminate in the way of the keel bolts.

During the course of the investigation, the MAIB received much anecdotal evidence regarding matrix detachments on Beneteau First 40.7 yachts. Areas notable for detachment were in the forward sections of the matrix, commonly attributed to the vessel slamming, and the area around and aft of where the keel is attached to the hull, commonly attributed to the vessel grounding.

Difficult to repair

And it gets worse. Not only do these boats get damaged easily in a grounding or even from just hard sailing, it’s almost impossible to fix them properly at a reasonable cost. I won’t burden you with the details of why that is here—you can read them in the report.

Not just Beneteau

And such problems are not limited to the First 40.7.

We saw a modern Swan at Billings Diesel and Marine that suffered detachment of the matrix due to adhesion failure from a grounding.

In this case the repair was worth doing to this multi-million dollar boat but clearly it’s not a viable answer for a (relatively) inexpensive production boat since said repair (done right) to the Swan cost more than a second hand First 40.7 is worth.

So let’s summarize. We are building boats and classing them as ocean capable that:

  • Will be dangerously damaged by something we know happens frequently: grounding.
  • Said damage can’t be reliably detected and accessed with practical methods that are readily available.
  • Said damage can’t be properly repaired to original strength at a cost that makes sense in relationship to the value of the boat.

Report Recommendations

Up to this point, I think the report did a great job of analyzing a complex situation in the best way possible. But, in my opinion, the recommendations section is an epic fail.

Said section concentrates on improvements to:

  • crew training,
  • boat inspection and application of commercial classes (different from construction classes),
  • life-raft deployment,
  • and raising the awareness of the dangers of grounding this type of boat.

There is not one recommendation in the report relating to improving the strength of keel to hull attachments.

An Aircraft Analogy

To me this approach is analogous to an aircraft accident investigator saying:

We have identified that the wing spar will be damaged by an incident that typically happens several times over the aircraft’s life—say heavy turbulence—and that said damage results in high risk of the wings falling off, not only on this aircraft, but also on many, perhaps most, aircraft with this kind of wing spar construction.

Further, we have determined that there is no practical way to accurately determine when this type of wing spar damage has occurred or how extensive it is and that repair to the structure to original strength is problematic.

Therefore, we are recommending that flight crew training be improved, particularly in the area of identifying the cracking sound that comes just before failure and also in using the escape hatches and parachutes after the wings fall off.

Further, the wing spar should be inspected more frequently, even though we have already determined that it is difficult to detect whether or not said spar has been damaged.

Seriously, what I have outlined above, using an aviation metaphor, is exactly the way I read the Cheeki Rafiki report.

Safety of Flight

But I didn’t use the aircraft metaphor just to make a point. Rather I believe we need to borrow a concept from aviation safety:

In the design of aircraft, certain machinery and equipment is in a separate category, “safety of flight”. These items must be absolutely reliable and must be capable of enduring the worst environment that the aircraft may encounter. –Don Jordan, aircraft designer and inventor of the Jordan Series Drogue

Of course, in a perfect world, many parts of a boat would be so classified, but that’s not practical because boats would end up being as expensive as planes.

So we must strike a balance with, as I argued in my original article on this tragedy, keel design and build having the “Safety of Flight” standard applied because, if a keel falls off, particularly offshore, fatalities are much more likely than with most any other hull or rig failures.

John’s Recommendations

OK, I have been pretty negative in the last few paragraphs. And I’m a firm believer that if you are going to criticize the hard work of others, you had better be willing to at least take a stab at making things better.

So here are my recommendations based on the findings of the report:

  • The keel attachment construction technique used on Cheeki Rafiki—glued in matrix—is, in my opinion, fundamentally flawed and should be specifically banned under classing regulations like ISO and ABS.
  • These scantling regulations must be upgraded so that the keel to hull attachment will maintain integrity in a hullspeed grounding and also withstand pounding and slamming while sailing over the life of the boat.
  • Said upgraded scantlings should be a requirement for Class A (Offshore) classification.

Or to put it another way, I strongly believe that we must return to the time when keel to hull joints were built not only to be strong enough the day the boat was launched, but also to withstand common abuse, such as groundings and slamming up-wind—people make mistakes and safe offshore boats forgive mistakes.

I’m not an engineer, but I suspect that much of the path to returning to the days where a keel loss was unheard of will be to use designs in which the structural members that distribute keel load (floors) are glassed in individually with reinforcing fibres directly to the hull.

The other benefit—that I verified during a wide reaching conversation with the master boatbuilder that repaired the Swan—of this traditional construction method is that grounding damage is immediately obvious and relatively easy to repair to original or better strength at a cost of around 10% to 20% of a proper matrix repair.

What about cost and practicality of my proposed changes to construction standards? Well, that’s the tragic thing. I’m reliably informed that it is perfectly practical to engineer and build a hull to fin keel—yes, even modern deep narrow keels—joint that will withstand multiple hull-speed groundings without serious damage.

And the cost of said upgrade at build of a boat like the First 40.7 would be less than 1% of the original price tag.

Surely preventing more tragedies is worth that much?

It’s Not Personal

One more thing. I need to make clear that nothing in this article should be interpreted as criticism of the investigators and authors of the Cheeki Rafiki report.

Theirs was a hugely difficult job, which they, in my opinion, did well. Who knows, perhaps recommending sweeping reforms of building standards was not an option open to them, for reasons we are not aware of.

Further Reading

Comments

I have read the report through with great care several times and based on that effort feel that the above article is a fair and equitable summary and analysis of its contents. Having said that, I could certainly have misunderstood the report in one or more areas. If you spot any such misunderstanding or misinterpretation, please leave a comment, I’m all ears.

One other point. I will delete any comment that makes any accusation of fault in the loss of Cheeki Rafiki. My reason for writing this article was to try and make things better and avoid another tragedy—let’s all stay focused on that goal.

Copyright Acknowledgement

The images and quotes in this article are from Report on the investigation of the loss of the yacht Cheeki Rafiki—UK Crown copyright.

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Richard Dykiel

Thank you for this outstanding analysis.

RDE

Hi John,
Outstanding summary of the type that it is almost impossible for a committee of individuals with different industry connections to produce!
The only comment I might place different emphasis upon is the tendency toward “modern” keel designs with long lever arms and mounting areas minimized as to width and length. While it may be entirely possible to design a structure to support such a keel reliably after multiple groundings it is much more difficult and thus more expensive. Increasing the mounting base area is the most cost effective way of reducing point load upon impact and thus increasing structural reliability.

Nick Kats

Look at the pic – the keel was torn off sideways. And look at the keel base (where it meets the hull) – it is far too narrow.

Widening the keel base will allow keel-hull fasteners to move father apart.

Doubling the width will make this joint much stronger. Maybe 4x more resistant to lateral forces? (I’m no engineer, am most definitely not qualified to produce a formula giving the ratio of width to strength..)

Eric Klem

Hi John,

I agree completely. When I read the report a while ago, I found it very confusing how the conclusions didn’t seem to be related to the rest of the report. The simple fact of the matter is that you need to do stuff right up front as it is extremely difficult to fix issues fully during repairs. When something is designed and built, a huge amount of analysis goes into making sure that it meets the design requirements. To try to do that after the fact is nearly impossible for the average person and would be prohibitively expensive if a knowledgeable professional was hired. In the case of keels, I think that you need to design them for that worst case grounding load as otherwise you will never be able to truly tell whether it is sufficiently strong once you have had a single grounding.

Eric

Rob Gill

Hi John – thanks for this important addition to a very readable original report. Two things puzzle me that I would appreciate comment on:

Firstly, the report mentions their northern route to the UK and outlines reasons why they didn’t take the more usual rum (sic) route via the Azores. But it doesn’t mention the effect on the seas of the Gulf Stream running against the strong head winds forecast (and experienced) in what was foremost a “racing” yacht design. Would the Gulf Stream have been sufficiently dispersed at their longitude to not be a factor and therefore not considered in their report? I don’t have an accurate tidal/current atlas for the North Atlantic (being in antipodes) so it is hard to tell.

Secondly, there was no comment from the shore-base at the time (or in the subsequent report) to heave-to when the leak was detected, and especially once the keel junction became suspect. It seems from the report they carried on sailing (albeit with reefs) until the keel came off – why was this?
Surely heaving-to would have helped in finding the leak (kinder motion/attitude), minimised the ingress of water (less water pressure on the hull) and eased the stresses on the keel/hull junction? Heck, we heave-to when I spill my tea!
Maybe they knew this yacht design couldn’t be made to heave-to and if so, should the report have recommended including “proven ability to heave-to” as a mandatory (or at least strong recommendation) for offshore Cat 1?

Rob

Ian Tyler

John, thank you for such an erudite analysis. I did read the report a little while ago but hadn’t spotted the obvious omission that you picked up and explained so clearly.
The picture of the detaching “matrix” in the Swan 45 repair article illustrates the apparent madness of creating a design where the structural integrity of the boat is dependent on a “stick on” extra structure. Especially where this structure is almost completely inaccessible and virtually impossible to inspect without expensive deconstruction of the boat above it.
As you say – it would appear that this form of construction is fundamentally flawed.

Robbie Wilderspin

Hi John,
Thanks for a well worded and concise analysis and set of conclusions. I can say that as it coincides with my own view on the tragedy (but better worded 🙂 ).

The subject has been much discussed on the UK sailing forums, as you would expect. One aspect that has been talked about there is the idea of NDT examination of structures, much used in aviation and industry generally. It seems there are techniques that can be used to examine delamination in glass fibre structures already in use for yachts. These may lead to to a more cost effective survey techniques for the ‘matrix’ type of construction – though the fix cost is still as high the owner should have a better idea of the risk of failure.

Robbie

Matt

By all accounts, Beneteau’s QC was impeccable. And the design was, apparently, in accordance with the relevant codes at the time. Since it failed anyway – not just on this one boat, but apparently on many others – we must conclude that the code itself was flawed.

I am not ready to outright reject the hull/gridliner architecture, but it does introduce unique new failure modes that must be accounted for. Speculating a bit: Are designers mistakenly assuming that slamming and grounding loads are transferred across the entire bond area of the hull-to-gridliner joint? Unless the skin is almost perfectly rigid (unlikely), there must be substantial peel loading along the edges of the joint.

I’m honestly not sure what to say about the keel attachment design in this specific boat. Apparently it met the relevant codes, but I have a hard time understanding why anyone would bolt the keel to the hull skin and gridliner lower flange alone. It would seem to create tremendous stress concentrations, which could be avoided with just a bit more structure to link the keel with both the upper and lower flanges of the gridliner.

Also, why is it OK to hand-wave away problems with the keel joint by declaring it to be a routine maintenance item? Boats run aground all the time. Saying “you must haul the boat and have this structure inspected after a hard grounding (but not after a light grounding)” is equivalent to making the keel joint – a “Criticality 1” item, in NASA-speak – dependent on routine maintenance. Maintenance that, in this case, is expensive, time-consuming, and dependent on someone’s subjective judgment of what is a “hard” grounding. Economic reality rules supreme, and people don’t haul boats “just to be sure” when nothing is obviously wrong with them.

Victor Raymond

John,
Great article. I once kissed a rock with the Jeanneau SO 45.2 (Jeanneau and Beneteau are virtually the same company.) I did not loose the keel but the resulting damage (about $85,000 worth) was astounding.

Fortunately for me the surveyor was not going to sign off on the repairs unless the matrix was better than new. Jeanneau makes up the matrix from using wood scraps and whatever to make up the form. After glassing up the limber holes between each section are drilled out but not cored. The factory expects the wood to rot eventually but that the fiberglass is where strength is not the wood core. Hmmm….

The surveyor would have none of that. The whole matrix was rebuilt with solid timber encased in fiberglass resin. Then the limber holes were cored and drilled so moisture would not be in contact with the wood.

This obviously made the boat stronger and a bit heavier but worth the effort.
I wish all surveyors had the same knowledge, experience and guts to do the right thing for current and future owners.

Matt

“Wood scraps and whatever”? I can’t say I’m terribly surprised, but that’s not OK.

Maybe I was a bit too charitable in my choice of language earlier. Any design code that does not allow for grounding loads is not worth the paper it’s printed on.

This boat – this entire class – was structurally flawed by design. The flaws were apparently sanctioned by – and had their roots in – the design codes of the time. Despite being from a famous design office and passing meticulous in-build QC, it failed. Cheeki Rafiki was not an old boat; it was only in its eighth season and had seen a working life to date that was completely within expected norms for yachts of this type.

The keel attachment shown in Annex D of the report may have been drawn based on the ABS codes of the time, but I cannot imagine signing off on such a design.

Just because something meets a bunch of codes and regulations doesn’t mean that those codes and regulations are any good to begin with. The Ford Pinto met all the codes of its time. So did the De Havilland Comet. You have to apply good engineering judgment to the code itself as well as to the design; the code cannot be allowed to replace good engineering judgment.

Marc Dacey

Matt, I believe that part of the issue is that modern production boats take their design cues and “desirable characteristics” from race boats of the preceding generation. Of course, race boats are tailored for both specific and narrow parameters…and are frequently seen as expendable after very rough, if short, service lives. Cruising boats are just about the opposite in that they are meant to have long, and largely docile, lives with only occasionally materials-testing incidents in the form of sustained heavy weather or hard groundings.

And yet cruisers are “racier” than ever in terms of keels, lay-up and, it must be said in some cases, robustness of their internal construction. This makes big boats float along in light airs, the sort of weather the local day sailors and club racers enjoy. But it is not necessarily a great idea offshore, an environment which uses up lightly built boats faster than do inshore or coastal waters, on average.

RDE

Hi Matt,
To elaborate upon your comments about design assumptions in hull liner designs I’d add two real world observations:

1- It is impossible to produce a liner that is consistent as to thickness and three axis dimensions even if it were hand laid or infused— to say nothing of blown from a chopper gun. You will always have an imperfect fit between the irregular inner hull and the irregular “structural” liner. In addition because the part still undergoes the final stages of cure for days after removal from the mold, dimensions will always change somewhat . I’m thinking of a whole series of race car bodies I once saw abandoned at the Lotus Racing factory because they had warped after being removed from the mold .

2- The most effective bonding agents like Plexus achieve their tenacious bond by being somewhat flexible. Therefore when they are part of a sandwich that is asked to carry high compression loadings the actual ability of the bolts to transfer load is both reduced and unpredictable compared to a solid laminate.

My opinion— bolting a keel through a hull-to-liner sandwich is always a bad practice, no matter how many cost accountants and classification societies sign off on it.

Rumen

Thank you John for the good article. In my opinion, it reflects logic and common sense. You don’t have to be an engineer to come to the conclusion that the keel must always be attached to the hull no matter how hard the use and abuse is. It is beyond doubt that slamming upwind should not count as a cause for keel detachment. Groundings, even hard ones may cause damage but not to the extent that the keel falls of several months later without hitting anything. I cannot accept that the fault for Cheeki Raffiki tragedy lies in previous groundings, though this may be the cause. Many mass production boatbuilders incorporate a steel frame in the bottom part of the hull to which the keel is bolted. Is this that expensive?

Dick Stevenson

Hi John,
As a way of generating reasonable change in building practices, I would like to point out one part of our maritime world that stands in the way. This was a tragedy that could have been foreseen.
A couple of decades ago, I had occasion to watch 2 boats over a couple of weeks being hauled into our local boatyard after finding our local rock with their keel while traveling at cruising speed. Both were of a similar type to Cheeki Rafiki and both were being considered total losses as the repairs exceeded their worth.
I was appalled that relatively new, well known boats could be brought down by such a predictable event and wrote a letter to the editor of the various maritime magazines I read at the time. Not one, to my knowledge, ever saw publication. I have seen this repeatedly in our community’s publications: a shying away or ignoring subjects that might ruffle feathers.
There are, of course, many avenues to building a groundswell of change, but, to my mind, our publications could be a leader in this area of developing seaworthy boats and attitudes. To that end, they are largely dropping the ball. This tragedy was predictable and inevitable.
Dick Stevenson, s/v Alchemy

RDE

The likelyhood that a magazine owned by a publishing conglomerate will act as anything other than a mouthpiece for its advertisers is about the same as the probability that a politician can open his/her mouth without lying. LOL

I never cease to be amazed at how some people who have fallen into the gig of writing new boat “test” articles can look at themselves in the mirror. If they had spent all their careers behind the editor’s desk in Manhattan it might be understandable, but the individuals I’m thinking about have tens of thousands of delivery miles and circumnavigations under their keels. I guess they are just following the Golden Rule as explained to me by the corporate lawyer in one of my past ventures: He Who Has The Gold Rules.

Frans

Hi John,
Thank you very much for writing this!
I think this is really the missing piece, and it solved for me the subliminal unease I felt after reading about the whole affair.

Marc Dacey

John, this is an excellent and forthright piece. If debate between the cadre of structural engineers and N.A.s who are actually responsible for production boat design and the bean-counters who finance the construction is sparked, much good will have been done.

It does strike me, however, even as a non-engineer, that skinny, bladelike keels bolted only to the bottom flange of a grid could seem problematic to any small child who has encountered a see-saw with a fatter kid at the other end. The forces can be substantial!

I also recall about a dozen years back taking a close look at a new Dufour 40, at the time a reputable and “to code” builder. I found to me what seemed to be deficiencies in construction, issues with tabbling and layup and many other “shortcuts”. The salesperson assured me that this model was “rated Lloyd’s Ocean Class A” to which I replied “I guess the sea will have the final word on that.”

I have since gleaned the Lloyd’s specifications and the Recreational Craft Directive (RCD) in Europe in an attempt to understand *why* the standards exist…and where they might not be the best guide to what makes a small, seaworthy sailing vessel. I have concluded that the emphasis is largely on commercial vessels and that “certification” of a pleasure craft is not what it could be, leaving us disinclined to look at most newer production boats as candidates for offshore cruising.

Scott Fraser

John,
Thank you for alerting us to the MAIB report. Your post and the comments above are very worthwhile.

I alerted readers of SailNet to this thread and have made a long post there of my “takeaways”, which I will not repeat here. For those interested, its post #52 at…
http://www.sailnet.com/forums/vessels-lost-missing-danger/140818-4-lost-40-7-sinks-off-azores-15-may-14-a-3.html#post2879033
(Note that I blog there as “Billy Ruff’n).

Earlier posts have pointed to differences between ocean racers and offshore passage makers in design, construction and profiles of use, but have failed to note what I believe to be an important difference that is relevant to this discussion. Specifically, it is rarely the case that you find a tired, worn-out cruising boat in an ocean racing fleet, but the opposite occurs with some regularity. Tired, worn-out (and potentially structurally impaired) ocean racers quite often become the inexpensive means by which a novice sailor strikes out on the adventure of a life time.

Given the challenges faced in even identifying, let alone properly repairing, damaged boats build with hull -matrix designs, the recycling of retired ocean race boats into ocean passage makers seems like an accident waiting for a place to happen.

Marc Dacey

The sea is remarkably fair in the sense that it cares not whether you are in a racer or a cruiser upon its face. It will attempt to break up your boat and kill you in either case!

David e Bell

I was just looking at the pictures of the Vestas Wind grounding for another writing project I am working on. The forces that the keel in that boat must have been extraordinary, and it stayed attached (and yes the whole boat was rebuilt afterwards). The point is that you can build these mechanisms so that they are strong enough, and still go fast.

What is currently lacking is the will to build boats that are fast, stylish, affordable, and rugged. I do not envy the designers and the engineers, it is an uphill battle with their livelihoods on the line.

What we can do is to help lead a way to a system where basic regulatory guidelines have deep foundation in fact and testing. I hope there are some younger and passionate people reading this, it is going to be a long haul.

And then there is the question of the boats already in existence. At least with existing boats we can share what we know, and actively help those around us make good and wise decisions.

George L

The Volvo boats have canting keels; a completely different design and very strong

RDE

Hi John & David,
I think your argument that “modern” keel designs can and should be engineered to survive groundings misses the point about designing for the real world. Given an unlimited budget, brilliant engineering, and aerospace materials structures can be made incredibly strong. On need only to look at the modern F-1 or Indy car chassis that enables drivers to survive 80g impacts. Of course a Formula 1 team has 3-400 people all focused upon building two cars—–.

There is a huge difference between Morgans Cloud’s keel or a swept back C & C design from that era and what is commonly known about hydrodynamics today. But that does not mean that a “modern” deep blade keel with a bulb would make Morgan’s Cloud a better boat! And increasing the mounting base area is still the most cost effective way of spreading loads and simplifying engineering.

Even the Open 60 class has now mandated a standard “overbuilt” specification for the common canting keels. So why shouldn’t ordinary racer cruisers that receive ocean certification be required to sacrifice a fraction of percent of windward performance by meeting engineering and cost-friendly mounting base standards instead of just throwing more money at the problem?

David e Bell

I think it is critical that any new rule, regulation, or specification on this subject be simple, straightforward, and clear. That is to say, in language and concepts that owner and the person actually doing the repair understands the goal, the methods, the constraints, and how to tell if the job (initial build or repair) is executed correctly and as the designer intended.

Understanding will carry us a lot further than enforcement will. Culture is a powerful tool. Doing the right thing must be a matter of pride and not done from grudging respect for authority. Building strong is not enough. Waterborne structure has to be practically testable, and repairable. Anything less is asking for the water to be let in.

Let’s get those engineers and designers out from between the rock and hard place so they can do what they love to do, create beautiful efficient sailing machines.

Chuck Hawley

I completely agree with your comments. The idea of bonding a grid structure inside a hull with some sort of adhesive (even 5200), and then being unable to verify the bond strength after normal use strikes me as being completely unworkable.
I, too, lost a keel on a large sailboat, but luckily my fate was different than the crew of Cheeki Rafiki. The failure mode was completely different, however. The 10′ draft, 10,400# keel had nine keel bolts that were supposed to be welded to a fore-and-aft piece of SS plate inside the keel. However, the welds broke internally, so the bolts were able to slide out of the lead which surrounded them. The bolts, incidentally, were rod stock and not threaded stock, so the lacked any grip on the lead. Luckily, and for reasons that no one has adequately explained, we had enough stability to avoid capsize, even though we were sailing in about 15 knots of breeze.
Anyway, thanks for the insightful analysis.
Chuck Hawley

Chuck Hawley

Hi John,

My close friend, Stan Honey, is currently the chairman of the ISAF Oceanic and Offshore Committee, and he is pushing for more disclosure on keel failures on racing and cruising sailboats. I think ISAF has documented over 30 keel losses, some of which were on extreme boats like IACC sloops, while others were on production boats like this example and the Cape Fear 38. Incidentally, I thought the investigation into the Cynthia Woods keel failure was excellent. It helped me understand a ton about repair of fiberglass boats.
An issue that Stan is fighting is the unwillingness to reveal the results of lawsuits due to gag orders. It would be dramatically more helpful to have the veil of secrecy lifted so that we could benefit from what’s discovered in these lawsuits.
Cheers,

Chuck

Neil McCubbin

Good article and follow up discussion.
One cannot fault Benneteau for building to code. They are in a competitive market and any major expense beyond code would kill sales. It is not a matter of Benneteau profits, but of them surviving.
Since a boat built to codes failed, and others have too, it seems that the code is inadequate, and should be changed.
Defining keel dimensions is tricky, and will tend to block innovation. However, it would be possible to define minimum sideways and fore-and-aft loads the keel must sustain, including the appropriate allowance for fatigue, all appropriate to size and displacement of boat of course.
I am an engineer, but not expert in boat design. That said, I find it hard to see how a substantial improvement in keel attachment strength would be very expensive. John’s 1% of boat price seem reasonable.
To make this happen, and upgrade in code will be necessary, given commercial reality.

Neil McCubbin

I just read the annex to the report.
Seems to me that the report body missed some key points.
– Although the keel bolts comply with the standard of the times, the did so only by a TINY margin. The analysis considered the possibly that the visibly corroded keel bolt was weakened. In this case, the bolts were non-compliant.
– The backing plate for the nuts on the keel bolts did comply with a qualitative statement in the ABS standard that it be “substantial” but was below the ISO standard.
The vessel was designed for use within 60 miles of safe haven, not for open ocean.
In summary, the vessel was too flimsy for the open Atlantic

Ed Finn

John,
I just re read the article above on the loss of the Cheeki Rafiki, including the official report discussing backing plate sizes, past groundings and repairs,
the rating of the boat,etc.
I just took another look at the photographs above. Specifically, look at that photo showing a typical Beneteau 40.7 similar to Cheeki Rafiki showing the floor, hull ribs, keel bolts, and specifically the backing plates. I note the size of the backing plates .
Then compare that arrangement to that original photo of the upturned hull of the wrecked Cheeki Rafiki taken at sea.
Funny thing, I noticed that the steel backing plates are much larger then the corresponding holes in the wrecked fibreglass hull.
At least three of the holes are much much smaller then the backing plates. So how could these plates pass thru the hull when the keel detached without enlarging the holes? How did they ‘pull thru’?
Am I missing something here? Is it possible that the backing plates were missing … either since construction, or removed during a repair.
Ed

Drew Frye

I’m late on the thread, but…

1. Yes, advertising pressure is terrible. I write for several mags and I will not report on anything the advertisers sell. It is unethical. New boat reviews are obvious infomercials. I have been threatened with law suits 5 times (the most resent just a few weeks ago) for writing negative things supported by testing. It seems there are companies that would rather repel bad press through legal defense than R&D for better products. It tends to be the same companies over and over.

2. The problem with “rot away” wood structures is not the loss in wood strength. I’ve design equipment that way, and so long as you take no credit for the wood it is fine. However, you must allow for the wood to expand when wet and freeze in the winter. Thus, the bilge is a terrible place for this design method. Have we not all seen split rudders? I wonder if Cheeki Rafiki had frost damage?

3. Backing plates. I’m doing some studies on backing plates, breaking different materials against cored hulls. What has become clear is that when a large backing plate is needed, additional laminate is always better. With a plate, if the laminate fails at the edge, there is a zipper failure. Thus, if a 1/2″ SS 12″ square backer is called for, an additional 1/2″ of laminate over a 18″ square area with a 4″ backer is a MUCH better answer (the extra laminate is a 1/2″ backer that is bonded and will not zipper). A little more labor and curing time, but less weight and material cost. Anytime you see a large backer, view it as a short cut.

Paul Browning

Thank you forthis article John, with which I can only whole heartedly agree. I struggled through the report, not being an engineer or naval architect, and the many other documents concerning the loss of Cheeki Rafiki and, most tragically, her crew. I have sailed some considerable sea miles in a Beneteau 40.7 and my end conclusion was that since these boats were apparently not designed or built to withstand normal sailing conditions, I would never again set foot on another Beneteau yacht, nor any other Farr designed sailboat. What else am I to think?

Paul Browning

Thanks John, but surely, sooner or later, we do need to hold builders and designers of unsafe vessels accountable, more than, or at least as much as the rule makers. Merely letting them off the hook for commercial exigencies isn’t good enough.
Other builders and designers are building safe vessels which will stand up to the odd grounding, why shouldn’t we expect the biggest builder in the world and the most prominent designer to do likewise?

Paul Browning

Concede. Thanks for the article and the thoughtful consideration of my points.

Marc Dacey

I think the reality (having now been to 20 years of boat shows with increasingly frowny expressions when I look at how they are now built) is that the flaws aren’t fundamental, nor are they revealed, in fair-weather, primarily coastal conditions. Most modern production boats, most of the time, are not subject to anything like heavy weather offshore; to make them capable would be to make them more expensive, or slower, or both. A long sleek fin with a torpedo on it can be made, but not cheaply. I have a friend who races in Europe and we’ve had extensive discussions about how to bulletproof race boats for the ocean. He does not see his ideas, which I have to say are proven to my mind, widely adopted on production boats.

Everything will fail under severe enough conditions. It’s the expectations of what constitutes “severe” and what constitutes a proper, meaningful repair that people like delivery skippers have to gauge, unfortunately.

Philip Wilkie

After checking with Morgans Cloud I’m linking to this recent report here:

https://www.maritimenz.govt.nz/platino/default.asp

It relates to the loss of two experienced sailors off New Zealand in June 2016. I’m sure many here will be aware of the incident; but the official report is fairly recent. I won’t attempt to precis the details, except to say that it’s classic Swiss Cheese accident. And most of what went wrong confirms precisely what John and others have already covered in depth here at Morgan’s Cloud. The correlations are disturbing.

I’ve had the opportunity to speak with one of the external consultants; his language off-record is a good deal more salty than the measured tones of the report. As a result the one thing I can usefully add, that the report doesn’t dwell on, is that despite the years of experience on board, the chain of command (or responsibility) was very unclear. The ‘skipper’ was such really only a nominal title; in practise all the real decisions were being made by more experienced crew. And when both of them were no longer on the boat … the ensuing chaos was both desperately sad and totally predictable.

RDE

Excellent report:
A tragedy of errors for sure, but one that many of us have taken the first step toward and thru luck escaped unscathed. Mine involved an inexperienced crew 40 miles off soundings on the Oregon coast and a retired attorney as owner/skipper who was incapable of directing or leading his crew. Building wind and a 12′ sea state, oncoming dusk, and refusal to accept my suggestion to put a reef in the main while there was still visibility. The lesson I learned is to ignore the Golden Rule (He who has the Gold rules) when good seamanship demands that you take command.

When loads are of the magnitude that existed on Platino (Money in Spanish!), having a skipper and crew with a level of professionalism and coordination appropriate to the demands of the tasks is vital. As a yacht builder I’d add a few of my own requirements:
1- The crew must be able to access the helm station from within the vessel through a helm station companionway. Half of the boats over 60′ LOA ignore this rule. If the crew of Platino had been able to take control of the boat earlier in the chain of events outcomes might have been very different.
2- On a fully crewed large sailing vessel the watch in command always includes somebody stationed at the steering cockpit 24/7.
3- Autopilot systems must always have parallel system redundancy. I once worked on a 300,000# motorsailor where the Famous Designers provided a 10′ long emergency tiller arm as back-up that was supposed to enable the boat to be controlled in an emergency. LOL
4- Mission critical components like travelers, preventers, rudders, and keel attachment should be engineered to conservative first-principal criteria rather than by reference to scantling rules.

Paul Browning

Gee wiz, this sounds like lots of ocean passages I’ve made! I kept thinking “there, but for the grace of God, go I!” Too many very experienced people did not fully appreciate the risks they faced, especially from a comparatively simple system failure on such a big boat. A boom weighing well over half a ton swinging unimpeded is a terrifying prospect.
Often I’ve sailed big boats and wondered what might happen if … but not actually worked out what I would have done. And I’ve certainly never initiated a discussion on board about it.
It does make you think that there are really huge advantages of smaller boats that don’t need such massive engineering to make them work or keep them together. And that can rely on windvane self-steering.
The main take-out message for me is to workshop man overboard procedures with the crew and not underestimate the power mother nature exerts on big boats.