Another Big Canting Keel Boat has Blown-up its Mast

Do these relatively new 'Fat Head'mainsails and huge masthead assys have anything to do with increased top third loadings?

 

Artemis out of TJV -- Broken Mast

It is with no joy that I share with you.... another big canter has dropped its mast.

This from the TJV site:
http://www.jacques-vabre.com/en/s03_news/s03p02_detail_actu.php?back_mode=accueil&news=681

06/11/2007

Jonny Malbon and Graham Tourell devastated by blow just four days into TJV race “We were absolutely mortified,” said Malbon, 33, from the stricken boat. “We are very upset, not just for us but everyone who’s been involved in getting us to the start line.

The team has worked so hard to get the boat in such great shape and this race has been such a big focus for us for the past year. It’s really heart-breaking.”

Malbon said that while conditions had got worse during the course of the day and the wind has strengthened to 35 knots, the boat was performing well in the rough seas.“We had the masthead spinnaker and the full mainsail up this morning but knew that the wind was forecast to increase, so we put one reef in the mainsail and changed to the jib. We had been pushing the boat hard to try and make ground with the front group but we weren’t pushing too hard. You wouldn’t expect this to happen in these conditions, but it always happens when you least expect it.”

Malbon described the moment when the 4,340 mile race for him and Tourell was over, after just 575 miles:“We surfed down a wave, a pretty steep one, and then hit this wall of water in front of us. The boat literally came to a standstill and the rig just fell forwards towards the bow of the boat.
“We tried to save the boom and the bottom section of the mast but to save the hull, we had to cut them free and throw everything over the side – the rig, the boom and the sails.”

Artemis was in 10th position in a fleet of 17, 100 miles off the coast of Vigo (Spain) when the dismasting happened and trying hard to close the gap on the leading boat, Safran, 130 miles ahead.With Malbon due to take part in the 2008 Vendee Globe round the world race starting in November, the Transat Jacques Vabre, and a solo trip back from Brazil later this month, was seen as a crucial part of his preparation for next year’s blue ribbon race.

“We are all devastated by the news,” said Mark Tyndall, CEO of Artemis Investment Management. “This race meant so much to the boys and they and the rest of the team have worked so hard in the past few months. They were very confident they could surprise a few people in this race and put some markers down ahead of next year’s Vendee Globe campaign. We are just relieved that they are both safe.” Malbon and Tourell are currently off the coast of north west Spain, waiting for the rescue boat, which is likely to be with them in the next 12 hours.


Here's hoping that the guys on board make a safe passage back to Spain and get their boat together for the Vendee Globe event in the future.

 

Chris,

This discussion seems to be one of those in which most participants are really in agreement on the fundamental issues, but believe they are at odds because they are explaining similar concepts in different language. No disrespect intended, it happens often, but it really seems like you guys don't differ as much as you think.

Look at the various points made:
Canting keel boats seem to suffer a higher rate of rig failure than fixed keel boats.
Canting keel boats are the pinnacle of high speed monohulls, much faster than fixed keel boats, approaching the speeds of multihulls.
Canting keel boats are so fast in part because they enable significantly larger sail rigs on the same hull size.
Canting keel boats greatly reduce heeling, drastically altering the forces acting on hull and rig.


I submit humbly that it appears that the canting keel is a major cause of these failures, albeit not the direct cause. The direct cause, as always, is equipment failure, and the causes of equipment failure are what they always are: defect in design, manufacture, or installation; or imposition of a force far exceeding prudent design and safety limits, either by operator error or freak natural condition. The canting keel is certainly a significant indirect cause, because it introduces larger and different forces from those induced by a fixed keel. Open ocean racing exposes a boat to an infinite variety of wave/wind/speed combinations, and speed multiplies every force. It's not possible to predict all of them. In short, these cutting edge racers, always pushing the limits of equipment strength vs lighter weight, are constantly testing the limits. Add a major breakthrough that transfers very large forces in ways different from anything before in monohull design, and the higher failure rate doesn't seem all that surprising.

A similar situation exists in formula auto racing, especially Formula One. For the past 20 years, aerodynamic force control has been the dominant breakthrough, creating downforces so great that cars can corner at speeds unheard of in earlier years. One result of the huge and different dynamic forces has been failure of suspension components at a much higher rate. There is general agreement that downforce generation, with its affect on everything from cornering loads to braking, is the largest contributor to the higher loads leading to suspension failure, but the faster lap times resulting from much higher cornering speeds mean downforce is here to stay. Over time, design of small chassis components is improved, and the failure rate reduced.

IMHO, the canting keel is a major contributor to higher failure rates, but only as an indirect cause. The constant experimentation with stronger yet lighter components, larger sail rigs, and much higher speeds means predicting and designing for every possible combination is increasingly difficult. It doesn't seem to be a mystery.

 

Canters are bad.

The sky is falling. The earth is flat, because that's what I see.

 

Of course....and the constant pushing of new limits, the problems that are raised and the new solutions that are found is what contributes to better boats and rigs and not only the racing ones .

 

It seems people don't recall the late 1970s, when "gravity storms" on racing yachts were much more normal than what we are seeing today.

There was no canting ballast then, or even water ballast.

At the time we were going from the old, non-bending single and double spreader rigs to 3 and 4 spreader rigs that could bend a lot. Now we regularly see 3 sets of spreaders on cruising boats, with really no issues.

Every industry has a leading edge where limits are pushed, and failures lead to greater understanding. In today's sailing it seems the limit is being pushed on some of the Open 60 designs.

Before people begin making comments about what the primary or secondary reasons for failure are they should know what the failure mode was. I don't think that is known on many of these failures. You can't blame the keel, or the carbon composite construction, or the shape of the sails if the failure was a fitting that had been incorrectly machined or assembled.

 

As Paul says, in the late '70s masts fell like blossoms in autumn. I think there were two races (St Pete SORC '78???, Hobart '84????) where more than 15 sticks fell in a single event.

Then again, part of the reason that no longer happens was because rulemakers discouraged the designs that were more susceptible to operator error.

PS - are canters that much quicker allround? Sure they are quicker, but from what I've read (and it's no more than that) in boats like the Cookson 50s the canters are only about 3% or less quicker all-round.

 

The point to be made is that canting keel boats are not monohulls. There are obviously two hulls involved. One is the perhaps not traditional monohull and the other is the bulb on the end of the canting keel. Recent articles are confirming that canter operators run these vessels like multihulls. The bulb is positioned so that its wake form cancels the wake of the main hull and designers analyze the bulb using hull form studies involving torpedoes - and now I am saying they should analize amas.

Did we learn nothing from the TP52's? Vessels with ********* have yet to be shown worthy. Reduced heel (and reduced leeway) is better gained through internal ballast systems, hull form, retractable foils, and mechanisms of reducing sail area/ force or with traditional or nontraditional flying hulls. Is there still disagreement on this? Can we at least agree that canters are not monohulls? Lets work to have them classified as multis because that is what they are. Then lets dust of studies by Brewer. Blubs on fins - fixed and dangling - create drag that can be compensated for only in a narrow speed range. Sailboats can not be expected to be operated in those narrow ranges owing to maneuvers they must make tacking, jibing, and trimming. They must be designed to operate in a much wider speed range than a bulb can be designed for. Bulbs of all forms just introduce drag when taking a holistic approach to sailboat design. That was Brewer's theory out of Friday Harbor decades ago. The theory has yet to be disproven. We are no longer blind but can see. Can we not?

Frank L. Mighetto
member SSSS
member US Sailing

 

Canting keelers are great, innovation wont stop. We can go on forever trying to optimise hullforms and foils etc for an extra half knot but these leaps like the canting keels are essential to keeping the sport interesting to sponsors and everyone else. Accidents happen, it will take a long time to figure out all the safe stress values etc. but hey.
They are not multihulls either, maybe when they fly the bulb and keel as some of the open40/50/60's are doing these days they can be a quasi-multi.
The introduction of canters to races such as the Volvo kept it alive and now the next one looks to be great with teams from allover the world and thats what we need! Cant the mast next!

 

I'm looking at a few of the points that have been brought up so far here, among them:

- The loads on a canter's keel and rig are quite different in many respects from those on a conventional keelboat;

- Canters tend to be designed for very high speed, and so tend to be designed with ultra-light-weight hull and rig structures;

- Composite hulls, masts and rigging are frequently used in these boats;

- A remarkable number of these failures seem to occur in fairly tame conditions, on boats that have already sailed thousands of miles.

I'm starting to wonder how much of the problem traces back to our relative lack of understanding of the "wonder materials" (carbon, aramid, etc) that are used to a large degree in these boats. Specifically, how they behave under shock and fatigue conditions.

These are boats which apply tremendous loads on materials we really don't understand as well as we like to think. In the case of conventional keelboats, there is a wealth of empirical evidence to support estimates of the loads involved. In the case of canters, though, we are applying loads we don't really understand on materials we don't really understand. Some of these boats may, thanks to the enormous shock loads they take when slamming through waves at high speed (while supporting several tonnes of tungsten out the side on a huge strut), be fatiguing their composite rigs much faster than anticipated. After all, it's remarkably hard to predict how carbon and aramid composites will behave when fatigued.

I am sure the design offices responsible for these boats are analyzing the failures in great detail. I am also quite confident that few if any of them will share such data freely anytime soon.

It does seem, though, that there are long-term fatigue effects on the more highly loaded composite rigs of these canters, due to their high speed and large, relatively unpredictable load conditions, which may be at play. Fatigue problems in an advanced composite structure can occur gradually at the microscopic or even the molecular level, virtually undetectable until failure, even though the peak loads may be substantially less than what would cause an immediate failure. The ability of carbon composites to fatigue at the microscopic or molecular level with no visible evidence of such is still a new phenomenon and one that is not well understood.

 

Marshmat,
You raise very valid points:
Loads are not well known/ composite material structural properties can vary widely.
Very difficult design and operating space to work with. If approached from a reliability/risk engineering approach, these high uncertainties are increasing the probability of failure. And guess what- we are seeing failures. Apparently the owners are willing to live with this risk though. Perhaps if this risk was spelled a bit more clearly to them in the planning stages though, they might not be. Would you spend a wad of cash on a structure that had, hypothetically, a 20%, 30%, or 40% chance of catastrophic failure in the intended use space? What level of risk would you accept?

Of course we can default to the Mighetto design code and only allow boats with which he approves....

 

Marshmat, You raise very valid points:...Of course we can default to the Mighetto design code and only allow boats with which he approves....

The truth is often divisive. I seek not division but you have to realize that most folks do not live in a society where speaking truth is allowed. This is a uniquely US citizen right.

The entire world looks to US citizens to alert the world to products that are unsound. This is because in their societies, family wealth will be depleted proving what can not be proved but must be once spoken owing to this notion that royals can not be disparaged in any way - this notion of slander and liable.

It is US citizens using their right to play devils advocate that protects the entire world from wrong doers. We can not count on the French, the Spanish or the English for the truth about boat design. Their legal systems are stacked against truth. I tend to think Germans, owing to Luther are capable of speaking truth. Again all that man did is post the truth, as I do. He and I live by that code. I post nothing I do not believe but am open to changing opinion as the man who translated the new testimate into his native language did. Damn hand me a German beer.

So it is that the boat building industry seeks to educate US citizens, myself included, and as it happens I have been so educated in composite construction just for chatting here on boat design and on sailing anarchy and more recently on the SSSS board. Those who support truth paid 800 bucks to send me to a course and so now the payback to them. You argue like a barrister defending a wrong doer with the following comment:

Loads are not well known/ composite material structural properties can vary widely. Very difficult design and operating space to work with. If approached from a reliability/risk engineering approach, these high uncertainties are increasing the probability of failure. And guess what- we are seeing failures.

Composite construction is well understood in the power boat industry. This notion that builders are not responsible for de-lamination - as has happened with the US Volvo 70 - does not fit with reality outside of sailboat design. We have hydros slamming at over 100 miles per hour and they do not de-laminate. Someone messed up. The wrong core material was used (I suspect) and the skin didn't attach as it should have. The builder messed up or the designer messed up in not specifying how the composite was to be constructed. I as others have pointed out in this thread doubt the canting keel is to blame but the canting keel is an indicator of irresponsible design work that we should be criticizing like we in the US are critical of all things made in China. When a product - be it pet food or a TP52 or a Volvo 70 - becomes known to US citizens as a likely problem for society it gets disparaged. So it must be with canting bulbed keels which dog gone it really are multi-hulls by the way they are operated. They have no place in a mono hull race - period. Folks from outside of the US are trying so hard to get that message across but it takes an American to say so directly.

It is well known that water ballast systems eliminate much of the slamming forces being blamed for structural damage in the canters. We have examples. But I must address this last comment of yours

Apparently the owners are willing to live with this risk though. Perhaps if this risk was spelled a bit more clearly to them in the planning stages though, they might not be. Would you spend a wad of cash on a structure that had, hypothetically, a 20%, 30%, or 40% chance of catastrophic failure in the intended use space? What level of risk would you accept?

This is so owner society which is code for slave society. I have yet to tell this story to my minions but boat design now gets it. I discovered this at the International Boat Show in Genoa when I researched Columbus. Columbus wanted galleys, I think. He wanted those living in what became the US and Cuba to row boats into the wind. In many ways we can be thankful for this whole windward leeward race thing because it eliminates the need for slaves to row boats into the wind as was common in Columbus's time. It took several hundred years after the discovery of our country to eliminate slavery and that is a story for another time but the main point is that owners do not get to accept risk that their crews will be taking. Damn the King of Spain for this attitude in our sport. In Columbus's time the Spanish royals worked to prevent Columbus from using slaves for return voyages. How did Spain get so far away from its roots? Addict, perhaps you did not know what you were saying with your post. We who live in the US may have forgotten what Yanky Built means. I know it has been a great problem for those living on the east cost. My theory is that it is to easy for you all to visit the EU, get feed full of nonsense and forget what it means to be a member of the society we are proud of. Oh but lets just assume you were playing devils advocate. Nice play;>)

 

I think you need to travel. A lot. It is far from uniquely american.

********, you know nothing of which you speak.

Do you live in a bubble, by any chance?

So far all of your post is so far from anything resembling "truth", that I at first thought you were kidding. and I had stumbled upon the drivel thread unknowingly. But so far, your post is based on wishful thinking and an ignorant narrowminded perception of the world outside the US.

Big difference in posting something one believes (i.e. opinion), and posting "truth".

And you premis for that conclusion is that the world turns to the US, and the US is educating the world? Haha, you really can't be serious.

Your arguments are a joke. Your premises are pure dimwitted conjecture, and your conclusions based on those premises are utterly disconnected from the very same premises, because you make a leap of logic. The rule of thumb of always be aware when someone claims to have "the truth" certainly holds true here as well.

Haha, "wrong doer". Next, you'll tell me your from a southern state, and that "We're gonne get them folks! Bring it on!".

Yep, one should be critical of everything. Country of origin really has little to do with it.

[…]

You really do like to pad yourself on the back. What a joke.


It is well known that water ballast systems eliminate much of the slamming forces being blamed for structural damage in the canters. We have examples. But I must address this last comment of yours

People were going to windward long before Columbus.

Well, the world hasn't: Lowest bidding. Consumerism.

Yes, it's much easier to proud of something if you twist the facts to suit your opinion. But I guess you must really feel the need to do so.

I'm inclined to tell you the same, seeing how you have almost listed, one by one, all the "prejudices" about americans. Well, we are told they are prejudices, when ever we try to describe americans like how you have just done yourself, propably unwittingly.

 

Danish, Thanks for saving me from wasting my time. Gamage has merit compared to the drivel you endeavoured to address with a seeker of conspiracy theory. To quote another, the drivel thread calls for serious discourse.

 

hehe, yep, but that is the drivel thread. Much more leeway must be given there