New Zealand AC72, What I Saw Today

Technical discussion of ARC products
Bill Roberts
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New Zealand AC72, What I Saw Today

Post by Bill Roberts »

I was looking on U-tube today at the AC boats and what did I see? The New Zealand boat was approaching a mark. The boat was foil born. The skipper turned the boat about half way around the mark and then the boat came off the foils and dug the bows in and solid water came shooting down the windward hull and washed two sailors off the boat as the boat very nearly pitchpoled.
Here we are a few weeks from the real AC races and the skippers do not know how to drive their boats. When you are foil born you don't try to round a mark in a sharp turn like a 10 knot monohull. That was a dumb move. The guy doesn't know how to drive. The announcer did not know what to say. He couldn't explain anything. He just said "while rounding the mark the boat suddenly dug the bows in". Well duh, we all saw that. What happened was the skipper turned the boat too sharply and the vertical foils generated so much drag that they slowed the boat down abruptly and the inertia of everything above the vertical foils, hulls, people, rig etc, pitched forward just like passangers in a car do when the car slows down or stops abruptly. In this case nobody had their seat belts on when the boat crashed. Two people went overboard and the boat was lucky to come out of it with minimum damage.
This AC Race, 2013, has taken too many technology steps at one time. Technically the boats have run off and left the audiance. They should have made the change to cats with sails this year. Maybe next time add the wings and time after that add the foils. What we can see on TV now with these AC boats is something that most people, the general public, do not recognize or understand.
BY the way, if these technologies had taken place over 12 years or so, the skippers would know how to drive them also.
Bill
Last edited by Bill Roberts on August 19th, 2013, 10:05 am, edited 1 time in total.
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Re: New Zealand AC72, What I Saw Today

Post by havliii »

The only fascination with this particular AC Cup IS the technology. The racing is boring. The materials technology is simply beyond comprehension and the design work to create such machines is breathtaking.

'Test pilots' are requisite to any advancement in technology and I applaud these guys for having 'giant cojones' just to get on and then sail a 40 knot death trap. I wouldn't.
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Re: New Zealand AC72, What I Saw Today

Post by Bill Roberts »

Hot Shot,
I'm not sure what new technologies you are talking about. Carbon fiber catamarans have been around for at least 50 years or more. I built a carbon fiber RC27 in 1985 and sent it to Italy. C class cats have been using wings for several generations, at least 40 years. Moth class boats have sailing on foils for many years. A Moth class boat that sails on foils is commercially available. What is new is putting these technologies together on boats so large and showing them on TV.
This whole build up of AC45s on TV etc is to attract the audiance, the general public, to sailing. This year's AC Race is going to be televised. The TV is going to be sponsored. Companies are going to pay big bucks to show their commercials during the AC races. If the audiance is not large, like the Super Bowl, the companies that spent the big bucks for commercials are going to be very disappointed and they will not do it again and this would end AC Racing on TV. It would also impact any kind of sailboat racing TV coverage like in the Olympics.
I go to the Y every day and work out. I talk to many sailors, mostly keelboat sailors. They are turned off by these boats with wings and now the foils. This is just too much change too fast for many sailors. The boats don't even look like sailboats to them and these are people that have sailed all their lives. I am concerned that the business end of this AC plan may not work out very well.
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Re: New Zealand AC72, What I Saw Today

Post by fjviola »

GO Emirite Kiwi's .. BEAT Larry's Kiwi's! :lol:

franklin viola
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Re: New Zealand AC72, What I Saw Today

Post by SC15Av8or »

I go to the Y every day and work out. I talk to many sailors, mostly keelboat sailors. They are turned off by these boats with wings and now the foils. This is just too much change too fast for many sailors. The boats don't even look like sailboats to them and these are people that have sailed all their lives.
Yes Bill......And these folks at the Y are the same ones that are having a hard time embracing social media, home computers and cell phones. All these are technologies that have come too since the engine you helped design which is now the prehistoric radial engine of my times. They are now hi bypass and soon to be geared ultra high bipass. Even the resin technology I would bet is not the same as when you built that RC27 in 1985. Just like in the day when fiberglass was the newest technology used the resin technology changed then too. I would bet if you could talk to Thomas Tew he would say the exact same thing about the boats your Y buddies are sailing. Wing sails are what Mylar was to canvas now.

The shapes and materials and media might change but we are still sailors and sailing. We have to embrace the changes as it makes for the better of the many and not just the elite. This is what most are having issue with. You expressed it yourself
This whole build up of AC45s on TV etc is to attract the audiance, the general public, to sailing.
Now the commoner can see and get involved in yet another aspect of the elite. This is the barrier that was hoped to be broken down. With that I would bet sailing in general sees an uptick and even more so in catamarans all be it in the used ones and not the newer ones as they are still priced for the elite in these economic times. Why are the SC15's and SC19's no longer built?? The technology trickles down and soon I might be sailing a foiling winged sail Supercat.

I to use the Y too and see and hear these same folks talk. Though it is not your Y Bill. If you go to Golds Gym though, the younger and more open minded folks are there. Shaping the changes in technology that will some day have me saying "that airplane just doesn't even look like an airplane". I know I find myself already saying that about the cockpits for sure. Whether it is a failure or not the exposure of sailing to the general public will be a success. There for bringing in new and fresh minds and ways of seeing thing. I personally have learned more about the Cups this year than I ever knew and have attended the AC45 events in Newport and San Francisco. I might even attend The America's Cup in San Fran as well.
Lifes 2 short for cheap GROG
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Bill Roberts
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Re: New Zealand AC72, What I Saw Today

Post by Bill Roberts »

Hey pro,
I don't know how old you think I am but I never helped design or develop a radial piston engine for an airplane. The first engine I worked on was the J58 which powers the SR71 aircraft. This aircraft is the fastest aircraft ever built and it flies faster than 2,000 nautical miles per hour sustained, hour after hour after hour. That is a nautical mile ever 1.6 seconds. Then I worked on the US SST engine for a few years. Next came the F100 engine which powers F15 and F16 fighter aircraft. The last engine I did design studies on was the engine for the Raptor.
The keelboat sailors I meet at theY have cell phones and computers at home. They liked the last AC race and they liked it that the trimaran won. The tri makes a better cruiser than the cat. What left them in the dust was the wing and the foils. A wing is worth about 10% more boatspeed than sails. Is it worth losing a large fraction of the viewing audiance for 3 knots out of 30 or 4 knots out of 40? Who can tell the difference between a 40 knot catamaran and a 44 knot catamaran? You can't unless they are close together. If the viewing audiance isn't big enough, we are going to lose the whole darn ball game.
Now we go to the foils. This technology is a big difference in speed. We have not seen yet the top speed of a foil born AC boat.
I like all of this stuff myself but I am concerned that the viewing audiance may not be large enough to make the show a money success.
If the show is not a financial success, that will be bad for sailing and we will continue to be a minor sport.

BTW Pro, why would you write something about me connecting me with radial piston aircraft engines when that is not true and you did not check it out before you wrote it. This is the type of s--- I ran into on Catsailor and I don't go there anymore. Would you prefer that I not contribute to this forum?
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Re: New Zealand AC72, What I Saw Today

Post by Kevin Keller »

Hi Bill,

I don't think he was saying you designed recip engines, I think he was just talking about the leaps of technology and how newer generations view them.

I personally think the foil sailing and the speeds reached are exciting. I think today's youth are more interested in extreme sports and this might catch there attention.

No one here wants you to stop posting. Everyone here respects you and your knowledge. By the way two of my friends here at UPS flew the Sled (SR71), one was my roommate. Great guys.

On my way from Shenzen to Anchorage here in a few hours in a Pratt and Whitney MD11.

Kevin
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Re: New Zealand AC72, What I Saw Today

Post by havliii »

Bill,

Stay on the board and keep posting, enjoy the give and take, remember that everyone on this board owns a Supercat or an ARC catamaran, we are all members of the 'choir.'

We can argue endlessly about what is good for the 'sport' of sailing because there are no absolute answers. I think we will see an uptick in interest, no matter how big the financial disaster in San Francisco is. The old adage applies here, 'there is no such thing as bad press.'

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Re: New Zealand AC72, What I Saw Today

Post by Bruiser »

So back to the foils... Can we stick some foils on our boats? Or, are we going to have to start from the ground up with regard to the forces generated by these foils? I would expect that the loads on the hulls and cross beams would be significantly increased, is it a matter of beefing up the hulls, or the entire platform?

Thoughts???
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Re: New Zealand AC72, What I Saw Today

Post by gahamby »

Call Tom, see If he has a stock foil rig ready to ship. I am in awe of those AC 72s. Can you imagine riding on one of those things? The only boring part to me is having to watch the race on a screen. The racing tactics are still there. There just getting executed at 30kts. We will get the benefits of the technology these guys are testing to destruction. That being said, I kinda miss the 12 meters.
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Re: New Zealand AC72, What I Saw Today

Post by SC15Av8or »

Ouch Bill....

I was not bashing you or belittling any thing you have accomplished Bill and I apologize if you took it that way. Your posts here are invaluable to us that come here looking for tips and advice on how to make our 1980's era boats the best they can be. Most of them have no manuals any longer and have undergone strange modifications by the past several owners or there are so very few of these left no one knows what is the right way to rig these.

Kevin got what I was trying to say there Bill. I was not saying you designed radial engines but making the comparison between todays turbine engine Trent 1000/GEnx (2013 technology) to the J58 (1958 technology) to the radial engine. Through out my entire post I listed many examples of changed technology that yes might have been explored 40 or more years ago but none the less have changed and are new.....or shall I say newer. An open mind to change and advancements be it good or bad is what we have to keep here. There were plenty of AC boats that went through similar trials and tribulations prior to these AC72s and they were "cutting edge" technology OF THAT TIME. Only the sailing world was privy to these events though.

You guys in the skunk works projects did not get it right the first time out the door either. It took years of testing and DEVELOPING to end up with the leaking beauty that finally was the SR71. They even had to design a new fuel (JP-7) that had to be inject with triethylborane for that engine to work right. Though it could only carry enough for 16 starts, relights or after burner light offs cutting into its endurance. An engine that was original developed for the flying boat. Advances in technology.

What you and your Y friends are missing in the AC is the advances in electronic technology that being made in TV broadcasting of such events. All the telemetry that we get to see brings us the commoner on to the boat with these guys. Folks that cant afford to sail multi million dollar or even a $50,000 catamaran or mono hull for that matter. Its not all about the boat speed here all be it a large part of it. In the past you your Y friends and I would have been lucky to see just the final AC race broad cast on NBC, CBS or ABC and listen to a broadcaster tell you what you are seeing. If they felt it was worth their dime to do such. Now I can go to youtube and watch practice races and anything else that might happen on the water. I can hear the skippers disgust at when a part breaks or when he prepares his crew for a tack or jibe. Then I can share it with my family and others when ever. This alone makes it a success. Have you looked at the number of viewer that click on these youtube videos. Who gives a rats pat toot if the networks don't make their millions. It is with out commercials and free for all online.

This sport will only continue to be a "minor sport" as long as it is priced for only those that can afford it. That is a minor population. I see more used 1980's era catamarans than I have ever seen new ones. Bill I can say that I have NEVER seen a NEW Supercat, RC, ARC, NACRA, PRINDAL out on the water. I have seen newer Hobies though some are made of plastic these days. The prices for these new boats makes it for the minor few that can afford them. The rest of us are left to make the best out of 1980's era boats, sails and technology if we want to enjoy this sport. The AC 45 events proved this. Look at how many teams participated in those events. I think the last race had 13 boats in it, a record for an AC event. All could have been contenders for the AC but when you jump up to the 72 footers well you see who was left. Those that could afford it, four teams/people with bank rolls that have more than six zero's at the end. Media financial success or failure is not the answer to making sailing a "major sport" for the many. I have never seen a media broadcast of a Hobie sailing event yet they are still around and in the plenty and being made. H14's and H16's with much the same design. It was a boat made more for the masses in both construction and price. Not saying it was as good a design as the SC but I know I can not purchase a new SC15. Why is that ??? What would one cost today??? I know I can purchase a brand new fiber glass Hobie 16 that was designed in 1969. I would bet cheaper than the ARC17 built today.
Lifes 2 short for cheap GROG
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Bill Roberts
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Re: New Zealand AC72, What I Saw Today

Post by Bill Roberts »

Relative to the foil kit from the factory.
Thought is being given to the technology. The foils themselves are the easy part, no problem. The hard part is the control.
The situation is that lift varies with the dynamic water pressure, density X vel**2/2G. The foil has to be sized to get the boat up and flying first, at a lower speed. So we size the foils to generate enough lift to fly the boat at say 15 knots. Now the boat accelerates to 22 knots quickly. The dynamic pressure just doubled; the lift just doubled. If we do nothing, the foils will quickly climb to the surface of the water and jump out of the water, now there is no lift and the boat crashes. All of this happens in a few seconds. On the other hand ,if we affect the foil in such a way that the lift remains constant while flying, the the boat can accelerate more maybe up to 26 or 28 knots or more. All this flying time the lift must remain constant while the dynamic pressure, which is making lift and flying possible, is varying as the square of the speed. So, control is the tough part. The lift can be varied by changing the angle of attack of the foils. The lift can be varied by modulating a trailing edge eleron of flap. This was the system Sam Dradfield developed and was used on the Trifoiler.
Two foils must be controlled. The main lifting foil located just in front of the boats CG and then a trim foil on the rudder to control the attitude of the whole boat.
Now on a two man beach cat today, the sailors have their hands pretty much full. So, adding to what they are already doing such as trimming two foils in concert may be asking too much. This means the foil trimming needs to be automatic. This is the long pole in the tent. This is the problem or problems to be solved with flying on foils, the control.
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Re: New Zealand AC72, What I Saw Today

Post by SC15Av8or »

Well it is getting exciting. So controlling the angle of attack on the foil is what you are talking about Bill. Do we not already do that by shifting crew weight for and aft to drive the hulls deeper at the bow?? That would be like the Concord used to do by shifting fuel during flight for pitch trim. The wire guy would be the one controlling it by moving for and aft.
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Re: New Zealand AC72, What I Saw Today

Post by Bill Roberts »

Hello Grog man,
Relative to boat prices: SC 15s and 17s were built in the late 1970s and early 1980s; let's call it 33 years ago. The price of the boat today has 33 years of inflation in it. The exact inflation numbers every year can be attained from your local bank. For discussion purposes, let's say the average inflation rate over the past 33 years has been 2.5%. Raw materials for boat building have gone up much more than 2.5% per year. Harken blocks have gone up about 5% per year. Using 2.5% inflation per year for 33 years means that a boat built in 1980 would cost 1.025**33 times the 1980 price in 2013. Today boat building materials are much stronger and lighter than they were in 1980. Tom uses epoxy today rather than polyester. The foam has higher, stronger, tougher, physical properties. Boats are painted with aircraft quality paint rather than gel coat. This saves weight and lasts longer. Just adjusting the boat price for inflation, the math says a 1980 boat today would cost 2.259 times as much as it did in 1980. Todays SC 15s and 17s don't cost even twice as much as they did in 1980.
In the boat building business, the builder can take one of three roads. He can go for the cheapest raw materials he can find and use over the border labor and build a cheap boat. Or he can build a better quality boat with materials that in his mind justify their higher price and build the boat with very high quality labor and workmanship. The third road is buy only the very best materials reguardless of price as long as the have even a small physical property benefit. A boat built like this is a boat built with prepreg carbon and in an autoclave and very highly skilled labor. An example boat of this type is the M20 which costs twice as much as a $30K Tornado and has a PN one percentage point lower than a Tornado. What is your choice Grog Man?

A little history: When Boston Whaler bought SC, immediately they moved the factory to California. There they began using the same material suppliers as Hobie Cat ,materials like foam and resin and fiberglass cloth and over the border labor etc. It was all cheaper than the Florida materials specified in the hull construction manuals. It wasn't long until they had some fully built California SC17s. After that it wasn't long until some California built 17s broke their hulls right in front of the main beam. Darn, I wonder why that happened?
Last edited by Bill Roberts on September 2nd, 2013, 8:39 am, edited 1 time in total.
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Re: New Zealand AC72, What I Saw Today

Post by Bill Roberts »

Bruiser,
Back to foils: There have been two foil boats in production, the Trifoiler and the Rave, and available to purchase by the general sailing public. These boats worked; they would sail/fly on foils. If the sailing public wants foils, why didn't they buy these boats? Why is there a sudden interest in foils now and there wasn't one before? It sounds like some people would like to add foils to there existing boat. Making foils an "add on project' to an existing boat cannot be as successful and as fast as a boat built from scratch as a foil boat. A pure foil boat at 72ft would run away from these AC72s that we are all seeing on TV.
Foils don't come free. They add weight and the controls are complex. Complex controls mean strings to pull and push and change to stay up and flying. Pulling strings demands our attention which is already saturated keeping our simple boats at full speed. When there isn't enough wind to be foilborn and the foils are in the water, now that is really slow.
Bill
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