We investigate the causes of keel failures and find some worrying reports of near-misses

Keel damage is a very real danger

To contemplate the loss of your keel is to think the unthinkable. Yet in recent years there have been several cases that have reminded us that this worst-case scenario can and does happen.

Many of the recent incidents have been aboard raceboats, often fitted with high-performance keels that push the boundaries of design and technology.

But the loss of the keel aboard Cheeki Rafiki, which became the subject of an intensive search last year, sent shockwaves through the sport. This was a standard Beneteau 40.7, a boat that is anything but high-tech. With around 800 afloat, it is a modest design with a reputation for being a robust and reliable workhorse.

Furthermore, the 40.7 is not only popular, but is typical of many other cruiser-racer styles around the world. Far from being extreme, this was a tragedy that claimed four lives aboard a run-of-the-mill cruiser-racer and struck a chord with thousands of sailors.

It wasn’t the first case of its type, however. In May 2013 a Bavaria 390 lost her keel 650nm north-east of Bermuda while on passage back from St Maarten to the Azores. In this incident the two-man Danish crew were rescued from a liferaft by a Finnish navy ship.

Before that there was the case of Hooligan V, a production raceboat that lost her keel in 2007 and claimed a life. In 2005 a Bavaria Match 42 lost hers as the internal structure pulled through the bottom of the boat. In the same year Moquini, a Fast 42, lost her keel off South Africa with the loss of six crew.

Indeed, so concerned is the sport’s governing body, ISAF, about the incidences of keel failure that it has formed a Keel Structure Working Party to investigate the issue. Part of the group’s initial work was to develop a database of the reported failures. Currently, the list includes 72 cases since 1984, and in those 24 lives have been lost – a small number perhaps when compared with the many thousands of boats that have been built over this period, but unacceptable nonetheless.

The trouble is that these are only cases where the worst has happened and the keel has parted company with the boat. It is frequently difficult to establish the cause of failure, and particularly to separate a shortcoming in design or manufacture from a human error such as a grounding. In a world where online forums spread gossip and rumour at the click of a mouse, getting to the truth can be especially tricky.

Next: Damage to your keel when you go aground

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  • 7th_Knight

    ..”Equally shocking is the story of a charter boat that lost her keel after
    hitting rocks in the Isles of Scilly, but went on to complete three
    charters and more than 100 miles of cruising before anyone noticed that
    the 37-footer had no keel”…..
    That says something about the Boats ( a Jeanneau SO-37 ) Stability….!

  • Robin Adams

    Yes, but you are a professional (I imagine), and most of us are not. The technical guidance needs to be made freely available, so that all owners are able to keep their boats safe.
    See the comment further down the page from Tim Pyne, which is another example of how owners are not given adequate guidance. We are not all structural engineers or surveyors, and even if we were, we would need to understand the manufacturers design criteria.

  • Tim Pyne

    I have a First 36.7 which we’ve sailed for over 10 years and thousands of miles, and we’ve hit the bottom hard on more than one occasion. We thought about selling it a few years ago, and to my embarrassment, when the broker lifted the floor, there were a load of cracks. We had it fixed, and the guys who did the work said the 36.7 and 40.7 had what they called ‘soft bottoms’, meaning they normally cracked when grounded hard. The thing is the floors are screwed down and we should have looked, but we hadn’t and my guess is that nobody checked under the floors in Cheeki Rafiki either.

  • Paul

    Best take cover. Bye bye.

  • Ted Vary

    John, if the only design and testing criteria are as you say, then they do not take account of the kind of side loads I described, operating over a long period. Aircraft wing testing requires very many hours of the continuous flexing of the wing and mountings in a hydraulic rig, taken to the point of failure. This absolute limit is then factored to create a generous safety margin, and this process establishes the fatigue life of the structure. Bulb tipped, high aspect ratio fin keels and their attachment features are subject to similar side-load stresses. If they are subjected to similar testing regimes then I would be pleased to hear confirmation from the main design houses, plus the certification figures for minimum acceptable fatigue life. I can buy an aircraft for the price of a good yacht. I can have great confidence in the certification process for the aircraft. Yachts should be no different.

    Ted Vary

  • Tim O’Connell

    You really like drama don’t you. Competition, in anything is about pushing a few limits, but as in just about every sport, there are equipment rules, safety rules, emergency procedures etc.. Inshore and offshore racing is no different. If you took the time to search for the ISAF Offshore Special Regulations, you may get a more realistic perspective. Skippers and crew undertake a lot of safety at sea training and most races require it. As you no doubt know, you can have the best training, but make lousy decisions. Your sweeping generalizations tell me you have no experience in this area. I won’t disagree that SOME designs are poorly built and sadly, don’t stand up to what its CE certification indicates. I also wont disagree that more focus on scantlngs that really meet the use of a design is warranted. I know this from personal experience in sailing a production cruiser across the Pacific in conditions within its CE Cert. Having already replaced most of its standing rigging and key deck hardware with gear that would really do the job, and not simply marina hop, there was structural failure in the hull simply from torque and flexing in seas one would typically find sailing inshore. I won’t go as far as you however, in damning all fin keels, all spade rudders, all designers, and now apparently anyone that races. Oh dear.. The sky is falling in.

  • Paul

    A spade is a spade.

  • Paul

    Ridiculously slim scantlings. If any boat loses bits of itself it is clearly unseaworthy for the conditions it is expected to face. As for pushing a yacht beyond its limits? That is absolutely unseamanlike and exhibits stupidity, let alone responsibility for lives just for the sake of winning.

  • Tim O’Connell

    Pendulum rudders?? These are attached to wind vane autopilots. I think the term for the rudder you are talking about is spade rudder. In any event your claim that designers are playing with lives with this type of rudder is irresponsble and extravagent. It’s not the type of fin keel or type of spade rudder, it’s the specification for how they are built. Spade rudders have been hung from thousands of yachts for decades without failure. Are you aware that skeg hung rudders have failed, as have the skegs themselves? Anything can fail if pushed beyond the scope of its construction method.
    Are you also aware that keel sumps have also failed. E.g. The number of sump cracks on the venerable J120’s ? This is time for serious, and rational analysis of the loads, structural methods, racing rules that are slim on the scantlings, and handicap formulae to give more credit to promote more structure. It’s not a time for wild claims.

  • Spokane157

    And let’s not forget the fleet issue of 2005 Clipper ventures race, brand new boats so you can decide if it was design, or manufacturing that was the primary issue or a bunch of amateur but very experienced by that point (approx 12,000 NM offshore) sailors… Thankfully no loss but could have been a disaster. My personal feeling is that as costs have become an issue and manufacturing to specifications and tolerances better, margin of error has gone down. What was once protected by slapping on an extra layer or two fibre which sure might have weighed s bit more, and been a bit slower but was just a harder wearing boat that would last 30 years. That may have now gone to thinner material, that wears and ages much faster.

  • Andersons Abroad

    Most or all of the comments here seem to be considering that the boats need to withstand a grounding, or a large storm, or an impact with a rock, as well as the normal lateral forces from close hauled sailing at speed. With all those I do agree that these boats and keels should be designed with those factors in mind and largely I believe that they are/have been. What is interesting is that the examples given for keel failures in this comment stream seem to have occurred after some sort of maintenance event on the keel itself.. Surely we can’t blame the manufacturers for shoddy yard work right?

    I think the point that seems to be missing from these comments is that it’s very likely that the Cheeki Rafiki failure was not just all of a sudden a perfectly sound and maintained boat lots it’s keel. Being as how it was repeatedly sailed across oceans and participated in racing, it’s extremely likely that the keel bolts may have loosened to the point that the keel was not securely attached.. This means that the attachment point is no longer a solid mated surface, but a moving pivot point with the keel bolts taking repeated stress. Of course we don’t know this for sure but the evidence suggests this is a likely scenario. Again, assuming this is the case, we can’t go around blaming manufacturers for poor maintenance of a boat. It is well known that keel bolts should be checked and tensioned regularly ( I just checked mine last month ).

    Similar to various automotive and airline crash analysis done to determine what caused a crash or injury we need to do as suggested in the article and find the actual causes. We may find that the only time a keel fails on a production boat is due to human error and/or poor maintenance.. If that’s the case, then let’s ensure everyone knows who the bad actors really are.

    Just my $0.02..

  • John Squire

    The loads are not only designed to take static loads. I am taking from a racing yacht perspective. The loads that the keels are designed have to take the require loads that can be caused by a large impact.

    If you look at the latest crash – Team Vestas Wind in the Volvo Ocean Race the fin was not compromised in the crash even though the impact happened at top speed.

    Maintenance is Key

    I look after racing yachts with the high aspect ratio fins. We race the boats hard and it in inevitable that we have grounded at high speed. After this I have taken steps to have the keel inspected, keel bolts torqued and in some cases ultra sounded. I have never had any trouble expect for one bad grounding but we took the full maintenance steps and the boat is still racing hard now.

    Since the tragic loss of Cheeki Rafiki most of the racing charter fleet have had the keels removed, full check and the it all being reseated. Some of the boats had to have had work. A large number of boat owners believe that they don’t need to worry about keels which is insane. If proper steps are taken then it greatly reduces the danger of such loss.

    The keelboats and the keel should be checked regularly and also after any serious grounding or stress load. It is simple maintenance. The designers do know what they are doing!

  • Safety at sea should always be of paramount importance. Articles like this are excellent in helping to raise awareness of the dangers and risks associated with offshore sailing. We all need to work towards minimising the risks involved. The best way to honour those who have lost their lives is to ensure such tragedies aren’t repeated…

  • Peter

    It is clearly NOT too much to expect “a few bolts” to keep the modern style of fin keel in place and to withstand the loads on a yacht in rough seas. There are thousands of ordinary production yachts out there with fin keels coping with no problem. With the exception of the Bavaria Match series, I cannot recall any production yachts where this design method was found to be unable to cope with sea-going stresses. Most of the known examples of keel failures were either race boats or boats which had hit the rocks hard.
    Now, if you want your own keel to be designed to survive a heavy grounding then you should probably look to a different design than a fin keel – and accept the speed penalty that will go with it. For myself, I choose the massively better performance of a lead fin keel.

  • Phil Shaw

    There are a few “oversized dinghies” comments here, a term I’ve often used in the past.
    To be pedantic, calling these appendages keels is a misnomer. The keel of a vessel is its spine, upon which the rest of the structure of the hull is based. These appendages used to be known as “false keels”, or “ballast keels”, which was somewhat more accurate. Maybe a better term still would be “ballast blade”.

    Whatever, one does not need to have a degree in mechanical or structural engineering to appreciate that the lateral forces working on the ballast blade in a seaway are enormous, and it is a bit rich to expect a few bolts through the proper keel to do the job safely. Personally I’d be very reluctant to make an ocean passage or even just an offshore passage in a vessel dependent on a ballast blade for stability.

    Tony Bullimore’s experience in the Southern Ocean SW of Australia some years ago was yet another disaster of a ballast blade falling off.

  • Peter, you are stating my case for me 😉
    “a very much raced and rallied boat”, yes this is what it was sold as. A RCD Class A ie ocean going.
    It should also have been designed to cope with the stresses of grounding, There clearly needs some common sense here, but boats get grounded, ( have you read Tom Cunliffe’s recent article about cruising in the Baltic? )
    The problem is that the boat most of us cruise off England or race around the cans in the Solent and I sail from restaurant to restaurant down the Devon and Cornwall coasts is also a Class A. It doesn’t need to be able to cross the Atlantic in all weathers several times a year, so Class A should be renamed A – ie take it out in more than a force 7 at your own risk. What we are being sold now is fine as a Class A -.
    But there should also be a Class A+ for boats that will get “raced and rallied” and taken across the Atlantic and round the world. There would be a marked cost difference. They don’t need to be slower, just designed for the conditions that they will see.
    My worry as that if we don’t shake up the industry ourselves, maybe with the help of a “Ralph Nader” then sooner or later the bureaucrats will.

  • Ted Vary

    I am told that these high aspect ratio ‘blades’ with lead torpedoes at the tips are only tested against static loads. If so, this is dangerously inadequate and explains the tragic failures, even without taking account of the fact that some might have suffered grounding damage. When a yacht is rolling, the highly efficient aerofoil-shaped fin is exposed to much greater angles of attack than when steadily heeled and making leeway. This generates much higher ‘lift’ forces, and these in turn are often accompanied by the high momentum loads of a long, heavily tipped pendulum. It is clear from pictures that these excessive loads, applied to a very narrow attachment base, are not adequately transmitted to an appropriately designed web frame inside the hull. If aircraft wings were similarly designed and anchored they would tear off at the first sign of clear air turbulence. To be safe, yacht keels must be designed and tested to realistic, at sea dynamic loads, including yachts built specially for racing where the owner/skipper has a legal liability for the safety of any hired crewmembers. There is a simple solution, but it might knock half a knot of the top speed. How many lives is that worth?

  • Major overhauls as currently understood, do not include any check for fatigue damage anywhere in the hull or keel structure.
    The problem is that there are no existing standards for yacht design.
    Every industry has had it’s catastropic learning curve with fatigue. The aircraft industry had the Comet, and the offshore industry had the Alexander Kielland. As a result each industry has developed and implemented appropriate design standards. That is what the leisure sailing industry needs to do.

  • Shane Kennedy

    Given that skin fittings are only required to last for 10 years, a 40 y/o boat should have had several major overhauls ! These standards are not good enough IMO

  • It’s really not that difficult. The technology exists to analyse stresses caused by hitting a rock at speed and to calculate the fatigue damage over a chosen life, say ten years for an out and out racer and forty years for a cruising boat. Then to design the hull structure, keel bolts and keel for those conditions. And what’s more state the design conditions on the makers plate.
    But it’s the money.
    The reason we don’t sail long keel boats with skeg hung rudders is that they are slower and more expensive than the oversize dinghies we do sail. And the engineering costs money.
    Unless that bureaucrats run out of other things to regulate and start on our boats the only solution is for someone to start suing Beneteau et al. If the relatives and dependents of the crew of Cheeki Rafiki were to sue the makers, and it would appear to me that they have a serious case, things would start to change.
    Look at the way other industries deal with similar issues. All aircraft have to have an airworthy certificate and regular inspection. Would you accept it if your Volks-Benz fell appart underneath you? We need a Ralph Nader for leisure sailing.

  • Malcolm Black

    Lets get back to encapsulated keels and skeg hung rudders…. problem solved

  • Robin Adams

    Well done Matt Sheahan for writing this article and to the ISAF for the work of their working party. I feel considerably less kindly towards the manufacturers of these boats, who seem more interested in damage limitation than the safety of boat owners.
    After Cheeki Rafiki tragedy, I searched the net and found at least one other 40.7 which had needed work on a keel which had dropped a few millimetres at the leading edge. A couple of weeks later whilst on holiday in Les Sables D’Olonne, I glanced over another 40.7 in a yard and indeed, it’s keel appeared to have dropped a few millimetres at the front. If I am able to see/read this with my casual observations, should Beneteau not be doing something in the way of a technical bulletin to give some re-assurance to the owners of what is an excellent boat in so many other respects?
    Secondly, I do own a thirty year old Beneteau, and find it frustrating that Beneteau do not provide maintenance advice directly. Mine has a swing keel for which I depend upon forums, friends, and anybody who I can find to talk to for maintenance advice. Beneteau’s answer would be that I talk to their somewhat expensive dealers, who I have found to be variable in their helpfulness to older boat owners, and as you will see in the next paragraph variable in the quality of their workmanship.
    Thirdly, I found myself, on a friends swing keel Beneteau a few weeks after the Cheeki Rafiki tragedy last year in June when the following incident occurred. This was on a 1989 boat which had had it’s keel mechanism removed and renovated by a well known Beneteau dealer only a few months earlier. On leaving Boulogne to head back across the channel, I wound the keel down as we were heading out past the old harbour wall. When the keel reached the lowered position, I felt the weight fall off the bottom of the thread and the winding mechanism lifted out in my hand. Fortunately the wave height was no more than 20cm as we could then feel the keel swinging and clonking against the front edge of the keel housing. We managed to return and after a lot of work diving under the boat we got the keel re-attached. But, had this become detached whilst we were further offshore in rough conditions, I believe the keel would have smashed the keel housing to pieces.
    Am I being unreasonable in saying that the manufacturers owe it to their customers to provide a higher level of technical support?

  • Paul

    These boats are like oversized dinghies with bolted on keels which are very thin. This gives a very large mechanical advantage over the attachment points. An integral keel, moulded in with a curved fillet from the turn of the bilge is mechanically far superior. Pendulum rudders are another example, hanging on to a tube without lower end support. Designers are playing with people’s lives.