America's Cup Disaster

Did you notice the difference in rake between with jib and w/o jib?

That is quite a change.

R

 

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w/o jib less rake/ with jib more rake

edit: better picture of rake added 7:54
pix: Giles Martin-Raget

 

I meant to address this previously.

There seems to be a bit of sarcasm about Ernesto sailing his boat. Even Coutts took a shot a couple of weeks ago, saying something silly like Larry was the real sailor between the two owners. Coutts knows better than that and it was obviously childish taunting on his part.

Ernesto has won the Farr 40 Worlds (with Coutts on board). You have to be a pretty darn good sailor to do that.

He has also done very well in the D35 racing on Lac Leman. Some of the best multi sailors participate in that racing, and Ernesto more than holds his own.

 

Yes, I realize that Paul, know all about EB's boats and history - but Loic is a brilliant helmsman .... and A5 did not seem to be steered very well to me, seemed erratic, especially downwind, when USA hoisted her two hulls up and sailed ON RAILS, so impressive and wonderful steering by JS and sensitive wing trimming by the crew; maybe A5 just wasn't up to standard and that increased the impression of clumsy helming.

 

During the owner's talk before the match Ernesto was questioned about his steering. He said they had data that showed his steering vs Loic and Ed Baird and he "was not the slowest".

I'm watching the replay right now and BMW-O is not sailing "on rails". In the close shots you can see the pitching and course corrections, some really radical, to keep the correct attitude. Even the commetators have been mentioning "look at that" regarding the course corrections.

 

I was meaning USA's steadiness - obviously they're steering up and down maintaining wind flow - but in comparison A5 seemed to be dumping her windward hull awkwardly and quite often.

 

And USA just dumped their main hull a couple of times in the last minute or so.

There has been a nice shot of the two boats from directly behind and a long lens that foreshortens the distance, and you can see both boats sailing almost the same as far as compass angle and dropping the hulls, depending on where the puffs are.

I imagine the wing might make it easier to deal with those conditions.

 

I thought maybe USA-17 sails upwind under wing alone in stronger winds and they maybe just dropped the jib a little early. That might have been in preference to switching to a smaller sail. I also thought that it might just have been using Alinghi for 2 boat testing. When the wind picked up, they rocketed away again.

There was one time when it was obvious that alinghi was dropping ballast, but I wonder if their plan to balance the boat was to pump water and they couldn't react fast enough as pufs came and went. Downwind they did look like they were unhappy and having a hard time powering up and staying there. Maybe BMW Oracle was able to modulate power better. The heel angle looked very stable.

It may be that Oracle had the straight foils on the boat today because they were expecting light winds. Their hulls have tons of excess buoyancy, so I'm not sure the advantage of lift from a foil for them, even in heavy winds.

 

Another point: there was a lot of stuff posted well before pre race about the superiority of water ballast increasing power, blah, blah - and Alinghi dumped hers like a aerial fire dousing helicopter halfway down course. Ballast can increase righting moment, no argument, but it is also DUMB weight that has to be carried around. I'd like to know if A5 performed better without her water load on that final section of the downwind leg Anyone know anything ... or was that just desperation on A5's part?

 

The idea of water ballast is to have no more than you need and only in the windward hull. Then, in light air you have a light boat and in heavy air you can maintain the efficiency of the sail. Standard techniques to depower a sail, like twist, increase drag, which is always a bad idea.

I assume they dumped the ballast because the wind dropped and they didn't need it anymore.

 

peterraymond writes that A5's "hulls have tons of excess buoyancy" - and those hulls still, after all these months of training and trimming, have an unsightly bone in her leeward tail. Their hulls look ugly with too much rocker bottom and top and they still drag their asses. That leeward hull and stern waterline is halfway up the buoyant hull and there is a lot of drag there. Looks very similar to Britton Chances' Mariner's wake.

 

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Peter, did you mean Alinghi? If the foils are designed for it they will reduce the wetted surface of the hull and improve the overall L/D-it would seem she was fast enough for foils to be effective. Alinghi couldn't seem to keep the hull flying very long at times so the "S" foils they could have used might not have paid very large dividends today-I doubt the straight foils had any appreciable affect on wetted surface in todays conditions-they look to be canted about 10 degrees.
It will be interesting to see if they use the "S" foils next race....

 

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If anything she performed much worse-most of stretching USA did was on the downwind leg. At the windward mark USA was 3:21 ahead -at the finish ,not counting the mess Alinghi made of the penalty, USA was 9 minutes ahead.

 

I did mean Alinghy when I was talking about straight foils.

Of course now we all talk about how their design seems messed up. I've been surprised that even flying a hull the bow is sometimes out of the water. After using those tricks to lengthen the water line, it would be nice to use it. That's why I doubted the wings would help much. In light air you get no lift, or it has a high drag price. At high speeds you want waterline, not reduced wetted surface. Maybe it would help when the boat was powered up in strong breezes and was carrying a lot of ballast.

 

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Why? At high speeds the ORMA 60's and newer tris like Banque Populaire and Groupama place a premium on using the foils for lift(to reduce wetted surface) .Right now the Irens designed tri's Sodebo and Idec are undergoing conversions to foil assist. The Orma boats that used foils were almost always faster than tris that didn't particularly in heavy weather.
I'd like to understand your reasoning here-doesn't seem to square with the practical application of lifting foils?