34th America's Cup: multihulls!

Did everyone REALLY know the dangers involved?

I'm not disrespecting anyone involved, but Oracle were quite open about the fact that they learned a lot about safety from their capsize. After the capsize they went out and built a simulated cat to learn how to escape after a flip and things like that. So it is quite obvious that the sailors did NOT know of all the dangers involved when this class was created. That's perfectly normal since we tend to find out dangers with experience; for instance the '98 Hobart brought to light problems with the ABS treatment of decks. The ORMA 60 class only learned of the problems of their rule set with time. 18 Foot Skiff sailors only learned of the problems with flip-flop wings when people lost fingers. People do not have perfect foresight into areas they have never ventured.

We know from two of the biggest surveys about why people don't sail (ie last year's Yachting Australia study and the old North Sails/Laser-Sunfish one) that the major reasons people stay away from our sport are factors like its perceived elitism, difficulty and danger. We also know from studies and stats that sports that rate high on TV are often NOT popular in terms of participation. We also know that the TV stations have little interest in broadcasting the AC, and that we now have the smallest fleet for decades - smaller by far than the fleet that sailed through earlier recessions.

So people were encountering dangers they did not foresee, in a tiny fleet, in a failed attempt to attract a major audience that would probably merely hurt participation in our sport....is that worth a death like this?

Oh, yes, the boats get back to where they came from faster and sometimes go 80% as fast as a guy with a kite..... is that the consolation for Simpson's parents, child and wife?

One wonders how many people who are saying that this tragedy was merely a price to be paid for development have actually sailed extreme craft. Many (not all) seem to be just be spectators when it comes to racing fast under sail.

 

Well said.

 

Cracking the beam while towing then patching and hoping it will handle sailing loads is a bit like a new airliner damaging its wing taxiing on the runway and hoping it'll be good for that turbulent flight with the passengers.....

 

Artemis

Here is a video slide show found on the SA front page-picking up the pieces:
http://www.youtube.com/watch?v=QxHjFfGPwrA

 

remember too that this was only a mildly windy day on the bay.The kiteboarders and wind surfers were just starting to come out in the east bay

 

The designers, engineers, builders and sailors do not scrimp on the structure and certianly do not intentionally do anything "unsafe"

who are you kidding,
yourself ?

 

everybody knows these things are designed to collapse, to keep them as light and fast as all the other boats which are designed faster and lighter

 

Because I've seen this post by Magnus Clark/Blunted smothered with so many buttkissing +1's, +1000's etc. from <insult directed towards others removed> on SA, I feel that someone should tell it like it is...

Lol.

I've read through that whole exchange, where he is berating SimonN, and I would say that Magnus Clark there proves himself to be a grade A narcissist, desperate to reveal to the world his deserving some kind of distinguished medal for his own extended heroism since the age of 17, at least.

Very little of what he had to say, as opposed to SimonN's comments, had the slightest bearing on the accident in question.

After reading those posts of Clark's, I would never in my life want to be on a boat with such a <insult directed towards others removed> .



If anyone thinks my post here is off-topic, then please excuse my dragging SA feuds into the thread - but SimonN's getting browbeaten, shouted down, and ganged up on in such a manner, is again typical.

 

===============
Calling Magnus a dirtbag puts you in a very low category for a poster on boatdesign.net. This is NOT SA and most people here can find a way to use the english language in a manner to convey what they want to without personally attacking anyone. You should apologize to Magnus, or in my opinion, take a hike......
And Magnus is a friend of mine and that makes your post doubly offensive!

 

^^^

Feel free to be doubly offended in that case.

And aren't you triply offended, by my calling him a narcissist?

lol

 

Artemis

Statement by Artemis Racing ( http://artemis-racing.americascup.com/news/4526 )

Artemis Racing is in the process of conducting a thorough review and analysis of this week’s accident. As a part of this review, Artemis Racing is sharing and exchanging data and information with concurrent work being performed by America’s Cup and the San Francisco Police Department. Until this process is complete, any conclusions being made about the events that led to the boat’s capsizing and its tragic outcome are pure speculation. Out of respect for Bart’s memory and his family, we ask that the broader sailing community and others reserve judgment until all the facts are known, and not persist in unnecessary rumor. We again thank everyone for their continued support and thoughts during this difficult time.

emphasis added by dl

 

Grade A narcissist, thanks, as a narcissist I appreciate the attention.

That having been said if you are going to slag me I would appreciate that you spell my name correctly, it's Clarke with an "E". We wouldn't want anyone to be confused between my family name and that of our competitors team, Mr Steve Clark. My family has worked hard and long at developing the narcissist angle and I take the dilution of my brand very seriously, so get it straight.

Last I checked Simon is a big boy and can defend his views quite well and with a high degree of skill and articulation. I quite like him and enjoy his views, however on this occasion I did not agree and said as much. We have had many good debates in the past and no doubt will in the future.

If you think I am a douche nozzle, fine, so be it. If you have anything of substance to contribute to an important debate, have at it, less the ad hominum attacks.

Like anyone else if you have something intelligent to say, I have no doubt we'd all be thrilled to hear it, weather we agree or not.

Over to you Blackburn.

 

Further to my comments above a few points.

DL has cut and pasted quite a few comments of mine here. More often than not if I have comments on SA, it may well be in response to other peoples comments. As such, if you want to understand what I said etc, read it in it's proper context on SA. the point of my post which was being questioned is simple. Every time you step on the water, in any boat whatsoever, you take personal responsibility for your life. Simple as that. heroics at 17? no, I was in a bad wipe out and was lucky enough to survive, it was instructive, simple as that.

Stephen Ditmore.

I had a brief look at your post / question.

Might I suggest that at this stage of the rule development, it's still early days. to have prevented this kind of failure the rule could have possibly been written to say that the main beam would have to weight xxx KG. Then teams would have been incented to put X amount of structure / carbon into the beam.

However when the rule was first developed there was a desire to get a certain power to weight ratio out of the boats and there were some very basic weight bands set to determine the high and low possible weights of the boat. The bands were based on 2-3 boats that were designed as "cartoon boats" that represented a very good best guess as to what they would look like, weight, the structure they would need etc. Designers from a number of teams and countries participated in that process to give a range of ideas and approaches to the problems. I was one of those designers.

The basic assumption was that everyone would design to the low end of the weight band as a starting position, which is very narrow anyhow, and then the additional available weight would be used very carefully for repairs, changes, mods, and certain features on the boats. It was similarly assumed that no team would cut it so close on a major piece of structure that they would risk blowing it up, in favor of putting the weight into some unconventional, way out of the park piece of equipment. So in essence the narrow weight band was put into place to drive a kind of conservatism of design approach.

Further to that, when the rule was put together, it was widely understood that there were many possibly ways to skin the cat so to speak on how the structural assembly would work as a total system. You can see distinctly different approaches by each team. to that extent, there is an extremely broad approach to the design in structral terms, far broader then you see in monohulls which tend to converge on a single kind of solution due to type forming (monocoque). To that extent it would be very difficult to develop, "Scantlings" due to the massive divergence in the forms of solution. Now one could take a different approach such as static load testing that could be conducted by the ACRM. But that was not the case. Again when the rule was developed, nobody wanted to prescribe "what" the solution to any given problem should be, inclusive of platform stiffness. we can see how Oracle chose to use the weight for a certain kind of stiffness but with a clean aero approach, ETNZ, went stiff and lighter with a king post 4 way stabilized structure.

Beyond that, there is no way,in my personal opinion, that Artemis under-designed the main beam. I have only one other example of a similar failure that I am familiar with to look at and that is when Steve Clark's main beam likely failed while training with us in Toronto in 2010. We all know if a main beam fails, it's totally catastrophic, the whole show goes to ****, so none of us ever want that in any size boat. Steve suspects that his main beam suffered imperceptible impact damage during the capsize a few weeks earlier in Newport. He did not see it, or feel it, but he has speculated that when he wound up the boat in a good breeze in 2-3 foot short chop, it failed, in a manner similar to this recent tragic event.

I haven't got a clue what happened to the main beam on Artemis, but they did damage to it once while towing. I can fully understand how this could have happened. We are exceptionally careful about how we tow the boat for exactly this reason, composite damage to the most highly loaded element of the boat can be totally imperceptible and deadly to the whole program.

When it comes to designing the boat, at this stage, on our program, we are quite specific about the towing loads on the main beam. It is possible that this was not anticipated on the red boat. Again, pure unadulterated speculation on my part.

Again, I have no idea. With high end composite boats you have to be really careful about how you use them and ensure that you only use them the way they are designed. Before we try any weird ****, we call our designer with approximations of loads and the contemplated use or experiment to clear that we are allowed to use the structure in the way contemplated. Even then, we tread very carefully and listen for any weird noises and immediately stop if we are not comfortable. It's very time consuming.

So can they develop scantlings? Sure, probably, but only now they have way more data about the loads on the boats, and even then it would require a full top to bottom re-write of the rule itself and it would fundamentally change the design objectives of the rule in total.

 

Blackburn,

If you have some kind of pre-determined dislike of big cats or if you have some basic "we need to protect them from themselves" attitude, you may have viewed the SA postings differently than I did.

I am an engineer. I do understand the need to avoid speculation, jumping to conclusions, and unfounded global attacks.

In my view, most of Mr. Clarke's initial comments were simply pushing back at postings that I felt were some combination of unfounded, misleading, insulting and/or would have a negative influence on the sport.

Magnus did get into some back and forth with a poster I have seen get into on-line arguments before. Trust me, SimonN does not seem to be the kind of guy that will be intimidated or easily swayed from his opinions. I have seen SimonN make posts that provided relevant info during other discussions and was somewhat surprised by some of his positions on this issue.

Again, here at BDN most of us really prefer to stay more on the technical side and less on the "Anarchy" side that SA is famous for (attacking, insulting, bragging, rumor spreading, etc). I read a lot over there, but do not post a lot.

The post above by Magnus discussing structures makes it pretty obvious that he is actually one of the few that has the knowledge, experience and willingness to add value to discussions on the important issues. Many others with similar knowledge / background are probably holding back because they get tired of dealing with all of the junk from the "clueless but loud" crowd.

 

For Magnus or others willing to look for stuff that might matter,

Although the big cat concept is not "too unsafe", with the 2 high visibility events (Oracle PP and Artemis failure), there will be an increased desired to do what ever is needed to reduce the likelihood of more of the same. Many potential suggestions will be stupid knee jerk responses. However, I am sure that there is room for improvements in some areas.

For structural considerations, I was of similar opinion as Magnus about mandated design rules. However, I have been wondering about periodic mandated testing that ensures good safety margins for the loads that are being seen while sailing (if everybody has to test at 2X or 3X, they all pay an even weight penalty). It sounds good, but on the flip side, I worry a little bit about pushing carbon close to the limit and causing some of that "hidden damage" that Steve thinks he was a victim to.

The other aspect of high risk for the overall big cat AC effort seems to be related to a bear away Pitch Pole.

I have tried to think through choices that could be implemented to manage the PP risk. I am by no means really knowledgeable, and am just trying to throw stuff out to prompt thought by others:

• Sheeting in wings to stall them going into a turn,
• Increasing max available flap angle up top with a quick release to grossly "sheet out" and generally ruin airfoil lift
• Adding special flaps to detach airflow,
• Mandate no bear aways during any race with conditions predicted above a threshold (make them do upwind loops instead)
• Change the courses with wind predicted to be above a threshold to eliminate the need for a bear away (triangles anyone? - might get to see some really top end action - oops that might be high risk in itself)