“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. Here is an example of a modern Swan 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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Meet the Author

John Harries

John was born and brought up in Bermuda and started sailing as a child, racing locally and offshore before turning to cruising. He has sailed over 100,000 miles, most of it on his McCurdy & Rhodes 56, Morgan's Cloud, including eight ocean races to Bermuda, culminating in winning his class twice in the Newport Bermuda Race. He has skippered a series of voyages in the North Atlantic, the majority of which have been to the high latitudes. John has been helping others go voyaging by sharing his experience for twenty years, first in yachting magazines and, for the last 12 years, as co-editor/publisher of AAC.

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