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Thread ID: 135101	2013-09-24 22:10:00	America's Cup	Lurking (218)	PC World Chat

Post ID	Timestamp	Content	User
1354307	2013-09-26 09:02:00	Just been reading a very interesting article on stuff about the foils used on those boats ( both boats). Non technical version: The foils act like wings, hence how they "fly on water". Anyone who knows anything about aerodynamics ( I used to do a lot with it in aeromodelling trying to get more and more speed) will know theres a point that a minor shape change can make all the difference. Meaning theres a point that you can control how they act, and what you can get away with, go to far to reduce drag and they are very unstable, unpredictable in their behaviour. When they get to the unpredictable state, no human can control them, BUT a automated auto adjust system can. This means a lower drag system, under control will always be faster than the slower human factor. Take a modern fighter plane, basically a computer flies them, they are so unstable that no human can, if the computer fails the pilot bails out as they cant control them. This is more or less what happened in the USA boat. An example of this is when in the race that we were 1KM ahead in low wind, no foiling, we simply had the faster boat. For the technical minded, small piece from the article: A device known as “Little Herbie” was developed during the commissioning of the Boeing 747 Jumbo Jets over 40 years ago, to over come this tendency. Little Herbies, or “Stability Augmentation Systems” (SAS) as these are now designated, are equipped with sensors such as Accelerometers and Gyros which can detect and instigate corrections to stability with a speed and accuracy which exceeds the ability of even experienced airline pilots. They are therefore now installed in virtually all swept-wing aircraft. Boeing were embedded technical advisers to the Oracle team. The “legality” of this device has been justified and accepted on the basis that it does not actually “drive” the trim of the foils.....this is still performed by the muscle power of the crew, via hydraulic linkages. That may be so, but the device, using it's sensing and directives, has been described as “automatic”. This implies that the trim of the foils is determined by what can only be described as “superhuman” technology. If this technology has been used to overcome the foiling stability difficulties of Oracle it will have enabled the use of higher speed/lower drag foils which the crew would otherwise be unable to manage. This would give a significant speed advantage during foiling. This has been clearly in evidence since the modification. Improvement in stability and speed has been staggering. The high speed/low drag foils do have a downside in light conditions where, due to their lesser lifting characteristic, foiling is difficult or impossible. This was also clearly seen in the abandoned Race #13 when ETNZ were only 4 minutes from the finish, with a lead of over 1000metres. It was mentioned today, the biggest improvement to the US boat was changing the foils and the automated system it used.	wainuitech (129)
1354308	2013-09-26 09:41:00	WT, can you link the article please? Thanks	WalOne (4202)
1354309	2013-09-26 10:26:00	WT, can you link the article please? Thanks It was in one of the stuff articles, I've read so many of the comments lol. But I did copy/paste it to a word doc so here it is: So this just came through to me. Would be good for Stuff to check this out. It makes complete sense. And it seems this technology has been sanctioned by race authorities, so not cheating. But how come we didn't have Little Herbie technology on ETNZ? It surely would have been considered. And let's face it, we all saw the turnaround in Oracle's performance and it surely wasn't about "the team being determined and coming together". Also, if this is legal, how come Oracle didn't have it from the get go? THOUGHTS RE ORACLE'S REMARKABLE PERFORMANCE TURNAROUND. 1. It is well recognised that Oracle was having serious foiling stability difficulties at the outset of the regatta and that their performance could not match that of ETNZ. 2. Half way through the series it was acknowledged that Oracle had fitted an automatic control to their hydrofoil trim, and that this modification was approved by the measurement authorities. 3. Since this modification Oracle's performance has almost unbelievably improved. This has been “explained” by skipper Jimmy Spithill as being due to the superhuman efforts of the crew to improve their handling skills. However, in view of the intensive training Oracle were able to do, prior to the regatta, with their highly skilled team partner, it seems unlikely that only now have they discovered the “magic bullet” they they clearly have. It is much more likely to be the result of the modifications, possibly enabled by their surprising decision to use their lay day card and the subsequent lucky postponements. 4. It must be remembered that this is the first time that this contest has been sailed by yachts “flying “ on Hydrofoils and it is probable that new and different criteria should have been applied. 5. In the aeronautical world it has long been known that the stability of swept wing aircraft can rapidly be lost by uncontrolled yaw leading to a dangerous situation known as “Dutch Roll”. 6. A device known as “Little Herbie” was developed during the commissioning of the Boeing 747 Jumbo Jets over 40 years ago, to over come this tendency. Little Herbies, or “Stability Augmentation Systems” (SAS) as these are now designated, are equipped with sensors such as Accelerometers and Gyros which can detect and instigate corrections to stability with a speed and accuracy which exceeds the ability of even experienced airline pilots. They are therefore now installed in virtually all swept-wing aircraft. Boeing were embedded technical advisors to the Oracle team. 7. The “legality” of this device has been justified and accepted on the basis that it does not actually “drive” the trim of the foils.....this is still performed by the muscle power of the crew, via hydraulic linkages. That may be so, but the device, using it's sensing and directives, has been described as “automatic”. This implies that the trim of the foils is determined by what can only be described as “superhuman” technology. If this technology has been used to overcome the foiling stability difficulties of Oracle it will have enabled the use of higher speed/lower drag foils which the crew would otherwise be unable to manage. This would give a significant speed advantage during foiling. This has been clearly in evidence since the modification. Improvement in stability and speed has been staggering. 8. The high speed/low drag foils do have a downside in light conditions where, due to their lesser lifting characteristic, foiling is difficult or impossible. This was also clearly seen in the abandoned Race #13 when ETNZ were only 4 minutes from the finish, with a lead of over 1000metres. 9. ETNZ appears to have worked within the constraints of accepted yacht racing rules and the special America's Cup 2013 racing Rules to achieve foiling with these craft. This has been at the cost of using foil characteristics and controls which can be successfully managed by a skilled crew while having to make some concession to pure speed. 10. Although there is risk of being derided for being a “poor loser”, or a “bad sport” it cannot go unnoticed that Team Oracle have already been penalised for cheating, that previous Defenders have been noted for sailing very close to the wind of rule compliance. The recent outpouring of bluff and arrogance from Jimmy Spithill may well be part of a plan to trail red herrings and to draw the attention off the real technological reason for their quite literally astounding comeback. 11. The question is whether the use of a device which can enhance performance in excess of that achievable by human endeavour should be allowed in a sporting contest? 12. Is this grounds for protest? At least we should all be aware that this is how desperate sporting entertainment has become. One other comment I was reading as well. ( my wording here because I cant find it again :) ) Its plainly obvious something was controlling the angles and trim of the USA foils. Look at the first few races, The Americans when going around the marks and some harder tacks looked like lame ducks, almost out of control and sometimes falling off their foils. Yet after they made the changes as described above they went around the marks like on rails, rock solid. OK sure they may have learnt how to handle the boat better -- BUT over night from "God help us get around" to yawnnnnnnn so easy-- Dont think so ;) As I mentioned earlier, I used to lot with airfoils / Drag and it all makes complete sense.	wainuitech (129)
1354310	2013-09-26 20:08:00	Very interesting, will be worth keeping an eye on future developments.	Cicero (40)
1354311	2013-09-26 21:19:00	Here's some interesting data from the last race. AC Live Stats (live.virtualeye.tv) Briefly, the data shows that ETNZ's maximum speed was faster than Oracle (ETNZ averaged 45.72 knots vs Oracle's 44.33 knots). But ETNZ sailed further (22,757 metres vs Oracle's 22,054 metres). So Oracle's automatic trim may have helped a little and certainly they looked more stable in a gybe and around the mark, but what it comes down to is ETNZ sailed 700 metres more than Oracle. End of story, end of our cup aspirations. The question is why? Either the data ETNZ was being fed was faulty, or our interpretation of the data was faulty. Whatever, I just hope there's not a witch hunt brewing to apportion blame, our guys did amazingly well. I'd like to think Auckland responds with some sort of welcome home.	WalOne (4202)
1354312	2013-09-26 21:45:00	This is worth a read, a comment in Stuff today: The official America's Cup race data tells an interesting story. In the final race, Emirates Team New Zealand had a faster average speed on legs 2 and 3, but lost them both. They also had a faster maximum speed on legs 2, 3 and 4. On leg 3, the upwind leg, which is almost half the entire race, ETNZ's boat speed was nearly a knot faster than Oracle, but they took 30 seconds longer, and sailed 600 metres further, before they reached the mark. In the race, ETNZ sailed 700 metres further overall than Oracle and lost by 23 seconds. Oracle were faster through the tacks and jibes, but their boat speed was not faster than ETNZ. To sail 700 metres, at an average speed of 30kts, takes roughly 46 seconds. It raises questions about the data ETNZ were using to guide Dean Barker's choice of direction, and the decisions Barker and Davies were making. A deeper analysis would be needed to see if it was Oracle's tactics that forced ETNZ to sail further - most likely, that was part of what happened. But 700m is a lot of extra distance. To put it another way, in race 19, if ETNZ had sailed only as fast as they did, no faster, and sailed the same path as Oracle, they would have finished more than 20 seconds in front. They could even have sailed slower, and still won, if they'd sailed the same path as Oracle. This analysis seems to have been missed by a lot of commentators, who claim that Oracle were faster. It is true - of course - that they completed the race in less time, and it is true they were faster through the tacks and jibes, but the data shows they were not sailing the boat faster through the water. Instead, they sailed a significantly shorter course. The data demonstrates fundamental principles of racing sailboats - you not only have to go fast, but you also have to go in the right direction.	WalOne (4202)
1354313	2013-09-26 22:12:00	I discussed it with a work colleague, he pointed out that the speed difference might well be due to the different path which is to say if they followed the same path as Oracle there's nothing indicate they would still be faster. They may have been faster precisely because they went in a different direction. The bold text above is the most important point, it's a combination of speed and direction. You can't however look at the relative speed of boats going it two different directions and say one is faster than the other.	dugimodo (138)
1354314	2013-09-26 23:23:00	I discussed it with a work colleague, he pointed out that the speed difference might well be due to the different path which is to say if they followed the same path as Oracle there's nothing indicate they would still be faster. They may have been faster precisely because they went in a different direction. The bold text above is the most important point, it's a combination of speed and direction. You can't however look at the relative speed of boats going it two different directions and say one is faster than the other. Yea I agree, TNZ were going faster but that's because they were sailing slightly lower to the mark than Oracle. That's the fine line you have to ride when sailing, do we go at the mark more but at a slower speed, we'll travel less distance but it may take us longer, or do we sail lower and get more speed but that mean we have further to travel and probably also extra tacks/gybs.	CYaBro (73)
1354315	2013-09-27 00:03:00	Australia is not allowing Jimmy Spithill to return home. They're not taking any boat people.	Cicero (40)
1354316	2013-09-27 00:08:00	C'mon fellas, TNZ 8 to 1 and at match point, then TNZ falls over and loses the rest. Lurking. Ps. reminds me of my athletic years: Western Roll versus the Flop, I could never master the flop, so beaten every time. No machines involved just the style. lurks.	Lurking (218)
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