CHEEKI RAFIKI: Hull Found Again, Post Mortem

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Cheeki hull again

The fate of the four crew members aboard Cheeki Rafiki was confirmed on Friday when the U.S. Navy again found the overturned keel-less hull and inspected it closely enough to determine that its liferaft was still onboard. So with much drama and angst and effort we have at least confirmed what the U.S. Coast Guard initially surmised when it first suspended its search for survivors. I don’t think the effort was wasted or useless. Given the enormous interest in the fate of these four men, I think it was well worth it to achieve closure on that point.

I would hope some people who criticized the Coast Guard rather harshly for suspending the search might now express some regret (I noted, for example, that Brian Hancock, a well-known racing sailor, accused the Coasties of abandoning the search “without really trying”), but I’m not holding my breath on that. What’s more important is to focus on what we can take away from this tragedy to make sailing safer.

Capsized boat without keel

Time to wake up! This happens all the time

I’ve seen people discussing liferafts and such, but for me this big issue here is keels. The four crew on Cheeki died because the boat’s keel fell off, probably very suddenly, and this is not, as some have suggested, an unusual occurrence. It is frighteningly common. Modern fin keels fall off cutting-edge high-end race boats all the time (e.g., keel loss is a common reason for Vendee Globe withdrawals) and off less exotic race boats (e.g., I have one good friend who lost a keel off a TP52 while racing and know of many other similar incidents) and off common production boats, both while racing and cruising.

Cheeki damage

The underside of Cheeki Rafiki, showing the area where the keel ripped off. Note the large swath of damaged laminate below the keel’s footprint

On production boats like Cheeki, a Beneteau First 40.7, it is probably true that most keel failures are the result of damage sustained in groundings. This is a tricky business, as grounding damage can be very hard to assess accurately, and damage can be cumulative over several groundings. Even worse, with charter boats like Cheeki, there may be one or more groundings that take place and are never reported to the boat’s owner or those responsible for maintaining it.

For an excellent discussion of the damage sustained on Cheeki, I recommend you dive into this Sailing Anarchy thread here, from whence I pilfered these photos:

Cheeki damage detail

Enhanced out-take of the keel’s footprint from the image above. Questions raised: 1) are those bolt-heads and washers we see on the two forward keel bolts? Or are they broken off? 2) the aft bolt clearly seems to have been corroded, so is this where the trouble started? 3) the central bolts seem to have been the last to let go and took with them a big chunk of laminate, but was the laminate under the keel cored?

Barracuda without keel

Another First 40.7, Barracuda, that lost its keel. Note the similarity in the damage to the underbody

First 40.7 keel bolts

Keel-bolt pattern on a stock First 40.7, as seen from inside. Note that the keel’s attachment points are not tied directly into the structural bilge grid. Also, this is an exceptionally shallow bilge!

Interestingly, on page 7 of the SA thread you’ll find one participant, ClubRacer.be, who claims to have been on two different supposedly undamaged never-grounded First 40.7s where the aft keel bolts started weeping when you honked down hard on the backstay. Another commenter, axobotl, claims to have been on a First 40.7 that grounded at hull speed without sustaining any detectable damage.

Thinking of that rusty aft bolt on Cheeki, I have to wonder if this is a weak spot on all First 40.7s that have been raced hard. (And there are a lot of them. They have an active one-design thing going on.) If you trap moisture against that bolt every time you crank down hard on the hydraulic backstay adjuster, corrosion seems inevitable.

In perusing the online commentary, I’ve seen that some people don’t believe it is possible to engineer a bolted-on fin keel that is not vulnerable. That this is a risk you have to take when sailing on boats like this.

Personally, I don’t accept this. I’m not an engineer, but I have to believe it is possible to design a keel attachment that spreads loads over a much wider area of the hull. After all, we never (or at least almost never) hear of wings shearing off of airplanes. Yes, I am sure “over-engineered” keel attachments would be heavier (and thus would decrease performance) and more expensive (thus less economically attractive), but they must be feasible. On page 6 of the SA thread, for example, you’ll find links to a patented Swedish system for attaching a fairly aggressive fin keel that looks incredibly strong.

As a starting point, I would say a “properly” engineered fin-keel attachment should spread loads over such a large area that you should need to effectively destroy the hull to remove the keel (like on a full-keel boat). Also, there should be some mechanism or “fuse” that lets you know when the assembly has been critically damaged.

I can only hope that all the energy that went into browbeating the Coast Guard to continue looking for Cheeki might now be channeled into this purpose. Then the crew of Cheeki would not have died in vain.

How do we create this new standard of construction in what is effectively an unregulated industry? It would help a lot, I think, if race organizers and rule mavens started the ball rolling. If the high-end race boats whose keels fail most often were forced to be safer in this regard, a lot would follow from that.

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21 Responses
  1. Good analysis and probably right on target.
    Ironically,three days prior to this tragedy, we posted a newsletter discussing keel design, in which we talked about ways of spreading the fulcrum load created by a heavily loaded keel throughout the hull layup without having to go to a full, encapsulated, keel.
    Doing this properly does cost more money.
    And therein lies the problem. The high volume boat manufacturers, the ones catering to the charter trade, have to pander to a customer base which insists on increasingly more volume without having to spend more money. Compromises are made.
    Mostly this works because the bulk of these vessels are primarily used as floating resort cottages.
    The disconnect comes when someone decides to take one of these “modern” hull designs, that have had safety and quality compromised right out of them, and do battle with a cranky, old fashioned ocean.
    The ocean invariably wins.

  2. I do not fully agree with your comment that it is an unregulated industry. All Beneteau boats comply with the European Recreational Craft directive. For keel ISO 12215-9:2012 Small craft – Part 9:Sailing craft appendages applies, you might want to study this standard and give us back your comments on this as they might be very useful. The main problem with the RCD directive is that in most cases the notified body is requested for a EC-Type approval that means that based on one boat a whole production line is approved. Who wants to pay for a survey of his boat? After all they are production boats no? Well that is where mostly the problem lays a boat is delivered with a declaration of conformity signed by the producer but no external body/inspector has seen the boat. Are we ready to pay more for an inspected boat or do we rather go cheaper and accept the risks?

  3. Very good article and I agree that in postmortem it’s time to look forward and see how to prevent this kind of disaster from happening in the future.

    As far as my comment about the Coast Guard calling off the search prematurely… It’s always a tough call and I appreciate how hard it must be for the CoastGuard to make the right call. In this case they were wrong. Once public opinion forced them to resume the search they found the boat quite quickly and even though there were no survivors finding the boat and liferaft offers a measure of closure for the family and friends and sailing community at large. The value of that kind of closure can’t be measured in dollars and cents…

  4. Charlie

    @Peter: Yes, in Europe there are standards, and it would of course be very helpful if the EU promulgated stricter keel standards. But everywhere else the industry is unregulated. In large part, it has to be something consumers demand and are willing to pay for. I suggested starting with racing as it is discrete and seems more doable to me as a starting point and is very influential.

    @alina: A great way to support the Coast Guard is to donate to the Coast Guard Foundation at coastguardfoundation.org

  5. My first boat (Santana 22) had a cast-iron keel with a flange on top, with two rows of bolts through the flange and hull. First, this spreads the load over a wider area, like you said — it basically changes the ratio of the lever that the keel makes on the hull.

    But second, and maybe more importantly, it makes changing the keel bolts a nothing job that you would do every time you haul. You just take the nuts off the top and pop the bolts off down through the flange, easy. No need to move the keel, or even support it if you do one bolt at a time. Any sign of corrosion, just replace them. Or replace them anyway, what the heck.

    If you have a Beneteau, and you see some corrosion…. are you going to replace the whole keel?

    Iron wouldn’t be your choice, but a composite fin with a lead bulb at the bottom should make this do-able. It’s just engineering; given the will, it can certainly be done.

  6. Charlie

    @Brian: I agree with you entirely that closure was very important here. Well worth the trouble, and I hope we can now move on and do something meaningful with what was achieved here.

    I thought it was harsh of you to say they abandoned the first search without trying and if it were me, I’d apologize for that remark. They did actually find the boat the first time and made a perfectly reasonable estimate of how much longer to look based on what was found. They had no way of knowing that so many people would need closure in this particular case. When it was made clear, they resumed the search, and what was found in the second search totally validated the conclusions they reached the first time.

    I don’t think they deserve to be criticized in this.

  7. Jean-Claude Fontaine

    A lost keel event should be evaluated seriously by Beneteau peoples lost life these boat are week just ask travel lift operator and the will tell you the must take special precaution to move these boat in the yard.

  8. Keith J

    Hi Charlie, thanks for the articles and the follow up well done.

    Any thoughts on the impact that over tightening the rigging may have contributed to the load on the keel. Perhaps charter race crews tighten, race, and return and this gets repeated maybe with a grounding thrown in. That would give you one overstressed keel support.

    Cheers

  9. Charlie

    @Keith: I would think many aspects of a racing charter boat’s maintenance would be difficult to keep track of and keep up with. Rig tuning, of course. Groundings, not of all which you may know about. And just the fact that the boat does a lot of miles and is often pressed very hard when sailing. Even aggressive maintenance with a boat like this may still miss something, particularly a hard-to-assess issue like keel integrity.

  10. Andrew Troup

    It’s unfortunate to treat the ‘need for closure’ as the driving imperative. That’s effectively imposing an unlimited duty of care on search authorities (or limited only by external and capricious forces)

    The natural long-term consequence of delegating safety to rescue authorities is that they will seek to re-establish control over their exposure by lobbying for restrictions and norms.

    Sailing across oceans is not a human activity where convergence has been accomplished: unlike, say, on-road transport, where the engineering operates within relatively “closed” parameters.

    Sailing is like ski mountaineering, in terms of procedural and environmental challenges, where road transport is more like tennis. It seems to me no accident that ski mountaineering does not have tennis-type rules.

    We cannot eliminate killings in the mountains, or the oceans, without killing the activity.

  11. Andr

    This case comes to emphasize the need to ensure greater security related to Fin keel. Requiring innovative technologies to ensure the safety of boaters, without with it a hight cost or a major renovation on the hulls of sailing ships ever produced. Hopefully the incident, while tragic, will raise awareness and stimulate new solutions to problems. Be the improvement of materials, techniques used or new “viable” solutions to the problem. Boating safety is a pleasure and a duty for those who enjoys.
    O will not even go into the merits of being fair or not charging on the Coast Guard in search of sailors. Because I think there is nothing more that their obligation. As for the cost of inspection, should be absorbed in the cost of production. Aftter all, if a plane is not sold, if there is no guarantee that your wing would not fall. Similarly it should be seen to issue from the keel. It’s a safety issue, not a whim.

  12. Colin A

    While the ISO standards provide some guidance (and it is better than nothing) they focus on the design of the structure rather than the actual implementation. The keel design may work fine in theory but given the wide variance in strength in hand laid composites, my guess is there was not enough “safety factor” built in. Add in unknown service life and you can see why for years builders tended to over build there boats. (at least the layup schedule and structural reinforcement)

  13. Damon Gannon

    Just because your boat is big and expensive doesn’t mean that it is appropriate for offshore conditions. Designers, builders, and government regulators should learn from this tragedy (and other similar tragedies). More importantly, however, skippers and owners should know the limitations of their own boats. There is not much about the Beneteau First that suggests it was designed for trans-Atlantic sailing. Plenty of people cross oceans in boats intended for coastal sailing. By doing so, they take greater risks. These added risks may be small but they are real. Captains need to acknowledge these risks and make sure their crew members are fully aware of them. Ultimately, the captain is responsible for the safety of his or her vessel and of everyone aboard.

  14. StumpLifter

    I imagine the US Coast Guard has access to NSA satellites that can crawl up your behind and count your colon polyps from 200 miles up. I suspect that they made use of the technology before calling off the search. The mistake the Coasties made was not pursuing the “search” longer thereby making obvious the extent and range of the technology to the observant – including our enemies.

  15. StumpLifter

    Want to see change without oversight – Next time you are at a boat show ask every boat salesman “Is your keel attached using an American Bureau of Shipping Guide approved design or will it fall off like the Beneteau 40.7?” Guaranteed to get results

  16. Bill Durling

    Bill D. The boat manufacturers need to redesign these Keels to more of a permanent secure attachment or better access for regular maintenance. It can be done but it will cost some time and money which most are not willing to do. Therefore, it seems you are guilty of grundings unless you can prove differently.

  17. Paul Newell

    I’ve made comments on another string about the Oyster 825 who’s keel fell off last year. A boat that was only one year old!.
    This string about the First 40.5, and the accompanying photo’s, show the appalling way that these keels are attached.
    The bolts should pass through frame’s that go a substantial way up the hull. That would distribute the dynamic loads around the boat without them being pinpointed so closely together.
    This type of constrution is far to prevalent in modern designs and there is no need for it. And, I’m sorry to say, there will be many more fatalities to come as these, and other boats like them, get older and suffer the same fate.
    And what makes matters even worse is that both designers and builders know this and yet they still continue to design and build boats that they know are seriously under engineered, in both cruisers and racers.
    There is no excuse for keels falling off. It’s a basic principal that needs to be challenged at every opportunity. Why should we, as owners, have to put up with shoddy design and build. We all pay enough to at least know that we are safe whist at sea, don’t we?
    And as for one of the comments about boats being made to the Small Craft Directive…….. Not worth the paper it’s written on. (I always thought this the moment it was imposed on the industry) If it were then this thread would not exist and no keels would fallen off. Modern boats all seem to be designed and built to this minimum standard which is obviously nowhere near the minimum needed.
    If designers and builders are going to hide behind these useless directives then the system is rotten from the core and MUST be challenged and changed, for all our sakes.
    If anyone gets the impression that I’m having a swipe at the modern marine boat building industry, then good, because that’s exactly what I’m doing. I defy any boat builder or designer who’s keels have failed to defend their case. They can’t, otherwise we would not be where we are now.

  18. mARC

    After proof that the keel simply fell off another one of these production boats, maybe the author will apologize for implying the dead crewmen of Rafiki probably grounded it…..but im not holding my breath

  19. Charlie

    @mARC: You have completely misinterpreted what I wrote. I did not at all mean to imply that the crew onboard at the time had grounded the boat. Rather that the boat had been grounded by previous crews who chartered and never reported the damage to the boat’s owners. Incidents like this are apt to be common on boats chartered for round-the-buoy racing, as this one was. We have no reason at all to believe that the delivery crew who lost their lives had grounded or damaged the boat in any way.

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