Another Big Canting Keel Boat has Blown-up its Mast

[DGreenwood]

I guess I don't see a relationship of any consequence between car, bridge and skyscraper designers and people who design flat out ocean racers. One designs for guys that want to get up in the morning and go sell insurance, the other for guys that want to visit the most remote places on the planet, born on the wind, at speeds no sane person would choose, except the other guy he is trying to beat.

And as far as unknowns go, the primary unknowns here are human limits. The aerospace industry is miles ahead of the marine industry in engineering and manufacturing skills. What we know now about materials...carbon, steel, wood, titanium and Elmers glue, has increased exponentially in the last two decades. It isn't the lack of understanding that is the cause of the failures, quite the contrary, it is the confidence to engineer a machine that so nears the limits of human abilities. Sailors are still learning a level of sensitivity to the power and responsiveness of the new machines. Machines that are built to be very responsive in average wind speeds and at specific wind angles.It is not so alarming that it is possible to ask too much of them even in moderate wind.

No doubt the drive to win pushes design parameters to failure, but when has it been any different. Nothing changes..ever...including guys standing around pointing and saying they knew all along that we should have stuck with what we knew. Which is less than we will know tomorrow if we keep crashing boats like we have for hundreds of years.

[DanishBagger]

Isn't that the Microsoft-answer to anything:

"It's not our fault that you had a kernel panic, it's your own fault – you should have known not to right click on that part of the screen"?

Kidding, well, almost entirely, of course (How is that for an overuse of commas?)

[marshmat]

Interesting perspective, DGreenwood, and one that I agree likely holds a lot of truth.

My point in making the comparison with other, less radical fields of engineering was that in those cases, one will design with a very good understanding of the loads involved, with substantial safety factors, and with the knowledge that the result will have to tolerate tremendous abuse outside of its ideal operating envelope.

The racing yacht designer, if he were to adopt similar principles, is quite able to produce boats that don't break. But what the owners want, are boats that are fast (thus lightweight, built with complex composite materials, and with higher wind and keel loads and reduced safety factors), and that attract lots of media attention (thus, failure is not necessarily as bad as it sounds). So designers push the envelope, and the result doesn't have the same resiliency that you would expect in something that is meant to take a beating and last a long time.

In the end, we do learn from failures, and pushing the envelope is how we advance our knowledge of possible design paths. The fact that we are seeing failures, simply means that designers are in some cases pushing the envelope faster than the other players involved can keep up.

[Chris Ostlind]

You know... I'm really enjoying this thread... a lot.

Very nice contributions, boys.

[DGreenwood]

I think maybe I am trying to say that I think the engineers know full well how infinitesimally close to the edge they are designing
As mad as this sounds, how tempted and excited by the prospect of being in possession of the funding, the builder, the stats, the meteo data, the sailor, and the computing power to build that close to the edge, would you be? How fun would your job be if, armed with all that is available to us these days, we could run wild with it. Well, some guys get to do that. And, the sponsors, the sailors and the public are starting to dig it.

The solutions to these failures, I predict, will come in the form of learning tools for the sailors. Namely, load cells on the rigging, recording devices and software to analyze historical data and alarm during higher loads. F1 drivers are assisted by computers to make a corner, maybe software will help with keeping a rig properly loaded?
As we try to build boats that can maintain faster than true wind speeds in light air, the sensitivity is going to get touchier. We need some telemetry to help us make good choices in the Southern Ocean. I think this is what these guys are facing right now.

On the other hand, maybe some idiot on the build floor forgot to take the plastic off of one layer of the Prepreg before he buried it in the laminate.

[Chris Ostlind]

Geez, let's not get too simplistic with all this in the name of getting foamy about techno stuff. There are way more than that one guy on the build floor who can make substantive errors and make the whole thing go Ker-Blam!

Yeah, sure, who knows what is out there in wonderland as things progress, but it all comes down to human error and it can be manifest in hundreds of ways singly and hundreds more in complex pairings of singular foolishness.

Remember that wonderful turbine car of Andy Granatelli's at Indy when it lead the race by what, three friggin' laps? Then, when in sight of the finish line, a five dollar ball bearing set dropped the car to nothingsville. The next year the sucka was banished from the track. I never heard if that was metallurgy, lubrication, installation error, or what, but it is stuff like this that is the undoing of the most expensive, high-tech endeavors out there. You also get that salve to rub in your wounds and explain to the investors when you hang your hopes on the cutting edge.

And in answer to your supposition that the engineers on the rigs of these big dudes on the water actually know what they are doing as they tiptoe from one broken mast to another.... nope, I don't think they do know. Not yet, anyway. They may be closing in on the acceptable circle of doubt, but they ain't there yet. Well, at least I hope they are closing in after all the big time carnage.

[marshmat]

I think maybe I am trying to say that I think the engineers know full well how infinitesimally close to the edge they are designing

I think you're exactly right- they know that they're pushing close to the limits, and are right at the edge of known territory- in many cases a bit past it. And I think that they know full well that some of this stuff is going to break. That is the risk you take when you push the limits of what we know, understand and can simulate.

There is no real way to account for every conceivable factor in a design- this is why engineers build in a safety factor, to allow for the occasional foray outside the intended operating conditions, and to accommodate human error. Reduce the safety factor, provide the user a strong incentive to go outside the intended operating conditions, and add things like fatigue (of both boat and crew), etc. and your failure rates are going to go up.

No doubt the owners of these boats are aware of the risk. They didn't make their millions by being out of touch with what they do. But I'm wondering if, given the remarkable number of failures we seem to be seeing in the cutting-edge designs, whether the owners might ask the designers to ease up on the radicalness a bit and provide a bit more room for error. Or do they like the hundreds of news articles their uber-tech boat is guaranteed to get when it goes out in a blaze of glory, at least enough to justify the risk of pushing beyond the known envelope?

[RHough]

I'd like a combo please.

I think there is no single cause for the failures. Unfortunately we don't even have all the pieces to inspect or a data recorder that tells us what the conditions were when the stick came down.

It boils down to the fact that you cannot design a boat that is fool proof and at the same time competitive. Like aircraft, the boats are now have a design envelope. A "do not exceed" speed if you will. No one expects a pilot to guess what that speed is, the designer tells them. "Don't fly the plane outside this envelope or the wings will come of and you will probably die".

The VO 70 crews found some of this out through trial and error. They figured out that pushing the boat as fast as it would go would probably break it in some conditions.

There simply is not the budget for testing sailboats that the new boats would benefit from. Systems are not in place to re-create and find the root cause of the failures. If you want to know whats going on, all the boats need to be instrumented and equipped with data recorders.

Designing to a low margin of safety when all the loads are not known is a fools errand. It is the same trial and error process that yacht designers have used for years.

Way too many variables to draw a conclusion. Canting keels are not the direct cause, canting keel boats just load their rigs higher and differently than fixed keels do and so introduce even more variables.

If we had data that allowed failure to be properly analyzed we might learn something. Until then it's anybodies guess.

Make that a combo with no carbon, I'm going cruising.

[DGreenwood]

The comment about the prepreg was intended to poke fun at my own faith that it is possible to control the variables...except for Dave the laminator going out and getting good and drunk the night before. A joke..sort of.

This topic of unexpected outcomes in the use of materials and methods is obviously a well worn one.But every year I go to IBEX and hear repeated stories from designers and builders about lessons learned the hard way. It seems to be one of the favorite seminar topics.

One of the favorite ones is about the early days of FRP power boats. Everybody was trying to figure out the limits of the stuff and all kinds of testing and guessing was going on. They knew weight was killing their performance.
One of the big builders (can't recall which) decided the way to do it would be to build a paper thin hull, take it out and bust it, bring it back and fix it, and bust it again, and so on until they knew where to put the glass.

Effective back then maybe but that would be a very dangerous way to learn in this case. I realize Chris that you are not saying that anything so haphazard is occurring with these rigs.

What is peculiar about these failures is that I am not hearing why they are happening. In the past the cause of big mast failures would often filter down through the community and eventually you would see an article or hear somehow what the forensics said. In this case the silence is deafening. That is either to mask trade secrets or (more likely) crew errors that are best not made public. Guessing on my part...but good ones I think.

[TerryKing]

Originally Posted by DanishBagger

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

** Hmmm. A lot a political stuff just vanished from this thread. I think this should too?!! ***
I really agree with DB that you need to travel.

OH, MASTS!!!!

I DID read over a year ago that these boats HAD strain gauges and data loggers. WHY don't we see any of the data?? I'd love to see a graph of the loads on the rig just as it collapsed. And if that could be correlated to hull pitch and roll data, my bet it we'd see that the canting keel was actively used to counteract rig forces during a big puff, and produced dynamic rig loads that would not happen on a boat where the rig forces would quickly cause a heeling movement and lessening of wind forces.

That's my Mast Politics guess...

[DGreenwood]

Without spending too much energy on stuff that is already covered in this site and other sources concerning rig loads and their design considerations, I wonder if there are some surprises in rogue events or combinations of affecting factors on boats with canting keels.
Unpredicted rig shock loads that are a result of a some unusual combination of for example:

* Load from deceleration of the boat, the change in load direction resulting from apparent wind angle change. Any one who has tripped a Multi and blown up a spin as a result has experienced this.

*Load changes caused by the rig moving through pressure gradient changes as is moves vertically up and down on waves

* The way canters respond to approaching waves with a weighted appendage being exposed to different forces in a different part of the wave than the rest of the boat. In certain sized waves or approaching from specific angles there could be a perfect timing event. The force of the dagger board could play into this as well.

* The fact that the keel applies a desirable force in righting moment, also applies a less desirable lifting force on the opposite side of the hull. What structurally happens in waves as those forces are altered by them?

*Any thing that causes wild fluctuations in Rm in rhythm with other events that cause an increase in Rm or a decrease in rig stability.

I realize that any of these events are known and somewhat predictable. I am suggesting that possibly there are unexpected shock loads caused some thing in combination with hanging that weight out to weather.

No doubt data recorders would be ideal, I bet just knowing the conditions wind angles and sail combinations might shed some light. Maybe it is that horrible combination of leftover seas and light or moderate air that entices the sailor to put up too much too soon?

Ain't wild speculation fun?

[Chris Ostlind]

Originally Posted by DGreenwood

Ain't wild speculation fun?

Wild speculation is fun, D, and you know it.

Way back when in the 70's, I used to road race motorcycles. One time when I switched to a fatter, stickier back tire, I started to regularly break shock absorber mounts at the swing arm end of things. Went to a beefier swing arm mount and then the shock shafts started to bend enough to create fluid loss from the seals. After all the sorting, it turned out that the swing arm bushing set was too small for the increased loads being generated by the new tire. Wild spec might have gotten me there sooner, but the story just had to unfold on its own as I had not seen that problem before from the bike.

What you have written in the previous post is probably far closer to the actual events of these blown rigs than one might suspect.

When you look at the most recent dropped mast, it came on a boat (Brit Air)that had just emerged from the Doldrums and was starting to pick-up the steady trades at 15-20 knots. Out of nowhere, according to the skipper, the mast blows-up and he's looking for a fuel solution from his shore crew to get his butt to the Canaries. Too much sail area in frustration? Pressing too hard with the sheeting? Too much ballast taken on? Too fragile a rig? Who really knows?

The most recent Maxi-canter to blow-up, Maximus, dropped its rig in relatively light conditions at the Maxi Worlds, after having more serious bouncing the day before. These are not, apparently, connected issues as they come in direct opposition to one another. So what is left is WAG scenarios until some sort of data line emerges that can help predict the limits and when they "might" be reached.

The post regarding the utter lack of solid observation and testing, since the rigs are conveniently cut away, tells a bigger tale than we care to address right now.

[TerryKing]

Originally Posted by Chris Ostlind

..(snip).. The post regarding the utter lack of solid observation and testing, since the rigs are conveniently cut away, tells a bigger tale than we care to address right now.

Is the competition so bad now that people don't want others to learn from their mistakes? Ouch..

The best Engineers and Inventors I've known would tell anyone anything they knew, and always ended up knowing more and more. This was a blend of the altruistic and the pragmatic.

As Jay Lowe at IBM once told me (speaking of both knowledge and computer parts in his desk), "If you give away Everything, you have Nothing. But you can GET anything you need. Because Everyone Owes You."

I still owe him, but I'll have to pay it forward somewhere else...

I wish the competition was more about Seamanship...

[DGreenwood]

The secretive stuff is mostly PR people protecting image. There are some closely held cards but it doesn't take too long before they are shown. Recently, water ballast tank shapes and placements were staying hidden. PRB, Delta Dore and Temenos were being cagey about letting people see inside the boat. But builders talk and eventually designers and engineers talk, team members defect and word gets out. It is the nature of the game to try to get a little play out of your hard earned advances.
In the Ocean racing game the really valuable stuff is the computing power and the meteo data that guys like Farr possess. That stuff is years in the gathering and would not be given out on loan.

[marshmat]

I think there is no single cause for the failures. Unfortunately we don't even have all the pieces to inspect or a data recorder that tells us what the conditions were when the stick came down...... Way too many variables to draw a conclusion. Canting keels are not the direct cause, canting keel boats just load their rigs higher and differently than fixed keels do and so introduce even more variables.
If we had data that allowed failure to be properly analyzed we might learn something. Until then it's anybodies guess.

Bingo.

What is peculiar about these failures is that I am not hearing why they are happening. In the past the cause of big mast failures would often filter down through the community and eventually you would see an article or hear somehow what the forensics said. In this case the silence is deafening. That is either to mask trade secrets or (more likely) crew errors that are best not made public. Guessing on my part...but good ones I think.

Until some more information is available, all we have is speculation. But I must say, we're getting some pretty interesting speculation here.