Sailing on Foils? - America's Cup Thread

[ApS]

Originally Posted by NoBozo

WHAT's NEW: Hydro-Foils. These daggerboards are Shaped/Curved inward in an ARC...with a slight "Twist" & "Shape" in a hydro-dynamic way.. I believe this curved ARC Daggerboard IS the major lifting hydro-foil....any thoughts..?? NB

The foil is part of the daggerboard.

In the below attachments--taken from the video--it forms an "L" shape, which is tucked against the hull when retracted...

ETA:

...and forms "V" shape when immersed--a sailing foil shape learned from sailboat designs dating from the 1950s--perhaps earlier. Note the outboard and inboard spray from the "V" in the first photo.

Since the top of the "foil-board" is still exposed to drag, I think it is retracted to avoid "tripping-up" the boat when the hull returns close to steep waves at high speeds.

[NoBozo]

Originally Posted by ApS

Since the top of the "foil-board" is still exposed to drag, I think it is retracted to avoid "tripping-up" the boat when the hull returns close to steep waves at high speeds.

Catamarans with daggerboards ..the normal ones anyways, Always retract the "windward" daggerboard to eliminate "drag" on that side. The submerged board on the leeward side is all that is needed to prevent sideslip.

If the boat, (again..a normal one) is sailing Off the wind, ie..Tacking Downwind, quite often... Both boards will be retracted. NB

[garysanfran]

http://www.youtube.com/watch?v=IWxds...Ffcurv4mTxhjl0

27 mins into this, Emirates blows out it's jib halyard, has to cut the jib loose, jettisons it over starboard into The Bay. Very dangerous predicament. All very near The Golden Gate. The photography is exceptional.

[Par Four]

Originally Posted by garysanfran

http://www.youtube.com/watch?v=IWxds...Ffcurv4mTxhjl0

27 mins into this, Emirates blows out it's jib halyard, has to cut the jib loose, jettisons it over starboard into The Bay. Very dangerous predicament. All very near The Golden Gate. The photography is exceptional.

I just watched that race start to finish and I thoroughly enjoyed it.

You could fill book with what I don't know about sailing (and they have... How to Sail - 101). I don't understand the tactics or strategy of racing, but I really enjoyed watching that race.

I agree the the TV coverage was great,and very nicely supplemented with informative graphics.

This year I've begun to hear more of the calling of sailing, and not just because of the price of gas.

[garysanfran]

Originally Posted by Par Four

I just watched that race start to finish and I thoroughly enjoyed it.

You could fill book with what I don't know about sailing (and they have... How to Sail - 101). I don't understand the tactics or strategy of racing, but I really enjoyed watching that race.

I agree the the TV coverage was great,and very nicely supplemented with informative graphics.

This year I've begun to hear more of the calling of sailing, and not just because of the price of gas.

There are extraordinary forces acting, and counter-acting while sailing any sailboat, but these beasts! Unheard of until now!

Larry Ellison, Oracle, will be a hard fight against Kiwi's Emirates.

I understand the concepts of sailing very well, and have sailed the San Fran Bay for decades.

This, however, creates many contraries of basic sailing lore. The "apparent" wind is such that, because these beasts are traveling so fast forward, way beyond the wind speed, even with the real wind behind, the apparent wind is in front.

A summer of sailing on the San Francisco Bay...Enjoy New Hampshire!

[garysanfran]

The Swedes will join soon, they are rebuilding after their fatality disaster in May.

Artemis is scheduled to race within 10 days.

Today, the Kiwis won against Prada Luna Rosa.

Webmaster: Should we move this to a thread called America's Cup?

[ApS]

Originally Posted by NoBozo

Catamarans with daggerboards ..the normal ones anyways, Always retract the "windward" daggerboard to eliminate "drag" on that side. The submerged board on the leeward side is all that is needed to prevent sideslip.

Having owned three speedy catamarans concurrently, I found myself too busy with navigating to be overly concerned with the windward board; even with a crewmember, he'd be "on the wire" and oftentimes, the partially-retracted board would be clear of the water anyway.

Par Four, two of my catamarans, but especially my Tornado—with smallish centerboards—was capable of 10-MPH higher speeds than the AC72s are restricted to in these races.

But, according to July's SAIL magazine—dropped off by a bluewater-racer-friend—the real reason the AC72 windward boards are retracted is by safety regulation.

[SIKSUKR]

Standings
1.Emirates Team New Zealand 7-0 – 7 points (3 races remaining)
2.Luna Rossa Challenge 3-4 – 3 points (3 races remaining)
3.Artemis Racing 0-6 – 0 points (4 races remaining)

About today’s race
•Seven-leg America’s Cup course
•Course length: 15.43 nautical miles
•Elapsed time: ETNZ – 46:53
•Total distance sailed: ETNZ – 19.0 nautical miles
•Average speed: ETNZ – 24.41 knots (28 mph)
•Top speed: ETNZ – 41.16 knots (47 mph)
•Wind speed: average 15 knots; peak gust 22 knots

The schedule ahead (all starts scheduled for 12:15 pm PT)
•Thursday, July 25, Artemis Racing vs. Luna Rossa Challenge
•Saturday, July 27, Emirates Team New Zealand vs. Artemis Racing
•Sunday, July 28, Emirates Team New Zealand vs. Luna Rossa Challenge
•Tuesday, July 30, Artemis Racing vs. Emirates Team New Zealand

[garysanfran]

Originally Posted by ApS

Having owned three speedy catamarans concurrently, I found myself too busy with navigating to be overly concerned with the windward board; even with a crewmember, he'd be "on the wire" and oftentimes, the partially-retracted board would be clear of the water anyway.

Par Four, two of my catamarans, but especially my Tornado—with smallish centerboards—was capable of 10-MPH higher speeds than the AC72s are restricted to in these races.

But, according to July's SAIL magazine—dropped off by a bluewater-racer-friend—the real reason the AC72 windward boards are retracted is by safety regulation.

I don't think the speed of these race boats is "restricted"! I never heard of limiting the "speed" of a race vehicle. The only limit I am aware of is wind speed when the race will be stopped for safety reasons. The wind on The Bay can easily get close to 30 mph and more.

Your boat could go over 60 mph?

[Par Four]

I've been laboring under the non-sailors misperception that max speed of a sailing craft would be limited to the speed of the wind. Never thought any more about it.

But check me out to see if I now "get it" as result of watching the replay of Sunday's rce. I may invent some of my own words and concepts here, but humor me.

A sailboats speed is a complex relationship of multiple variables. Some primary variables are hull design and hydrodynamic efficiency, sail size and configuration/ shape, and apparent wind speed.

These foil equipped sailboats are able to reduce their hydro drag to minimal amounts, once the boat speed gets up past a crossover point of lift from the foils / weight of the boat.

I presume that cats do somewhat the same when they're able to lift one side out of the water, reducing drag, increasing the peed potential of the "lift" provided by the sail area, in relationship to the wind.

So with these foil racing boats, speed (obviously) can and does exceed the apparent wind speed due to minimal drag, and... The huge amount of sail area which give big time lift or pulling power in relation to the weight of the craft.

So the more efficient your hydro, the more efficient you sail geometry, etc, etc ad the better tactical sailer... The fast better you go.

Something like that?

[NoBozo]

Originally Posted by Par Four

I've been laboring under the non-sailors misperception that max speed of a sailing craft would be limited to the speed of the wind. Never thought any more about it.

But check me out to see if I now "get it" as result of watching the replay of Sunday's rce. I may invent some of my own words and concepts here, but humor me.

A sailboats speed is a complex relationship of multiple variables. Some primary variables are hull design and hydrodynamic efficiency, sail size and configuration/ shape, and apparent wind speed.

These foil equipped sailboats are able to reduce their hydro drag to minimal amounts, once the boat speed gets up past a crossover point of lift from the foils / weight of the boat.

I presume that cats do somewhat the same when they're able to lift one side out of the water, reducing drag, increasing the peed potential of the "lift" provided by the sail area, in relationship to the wind.

So with these foil racing boats, speed (obviously) can and does exceed the apparent wind speed due to minimal drag, and... The huge amount of sail area which give big time lift or pulling power in relation to the weight of the craft.

So the more efficient your hydro, the more efficient you sail geometry, etc, etc ad the better tactical sailer... The fast better you go.

Something like that?

Pretty much like that. The only thing I would modify in your description is Sail Area. In todays boats The BIG factor is Sail Shape rather than area. In this case (AC72s) the Mainsail is actually an "articulated" Wing..very much like the wing of an airplane which can be adjusted.

When the boat is Put Up for the night..the entire "Rig".. Wing Mast, has to be removed from the boat with a crane because the Sail can't be lowered as in "Ordinary" sailboats. The Jib is a conventional "soft sail" and can..as seen in the video, be lowered. NB

[Par Four]

Originally Posted by NoBozo

Pretty much like that. The only thing I would modify in your description is Sail Area. In todays boats The BIG factor is Sail Shape rather than area. In this case (AC72s) the Mainsail is actually an "articulated" Wing..very much like the wing of an airplane which can be adjusted.

When the boat is Put Up for the night..the entire "Rig".. Wing Mast, has to be removed from the boat with a crane because the Sail can't be lowered as in "Ordinary" sailboats. The Jib is a conventional "soft sail" and can..as seen in the video, be lowered. NB

Thanks. One can only imagine the expense involved with an America Cup campaign... Keeping up with the Jones, getting out on that leading edge must be crazy competitive, crazy expensive.

[garysanfran]

It takes three hours to set-up, and three to take-down. The wing is 130' in height off the water. Seeing these boats up close and in person, is a humbling experience. Awesome machines.

I believe Artemis is back in the water, practicing, and Oracle is also practicing outside the racing boundaries and carefully watching and analyzing the competition.

[NoBozo]

It was either I, OR the Webmaster that posted ON this forum an excellent video of the 2010 Oracle Trimaran "Flying" the center hull. I Searched here as well as YouTube and didn't find anything worthwhile. I found Some videos but NOT The GOOD one. NB

[Par Four]

Originally Posted by garysanfran

It takes three hours to set-up, and three to take-down. The wing is 130' in height off the water. Seeing these boats up close and in person, is a humbling experience. Awesome machines.

I believe Artemis is back in the water, practicing, and Oracle is also practicing outside the racing boundaries and carefully watching and analyzing the competition.

So whats the smart thinking here? Is this gonna be Oracle against Emerites NZ? Are the others really able to compete and win?

[garysanfran]

Originally Posted by Par Four

So whats the smart thinking here? Is this gonna be Oracle against Emerites NZ? Are the others really able to compete and win?

It really is too early to make a prediction. There is a lot of sailing left, and after every race, the teams meet to fine tune their skills and the boat. Engineers make secret changes to their boats as the evolution of the race continues. Angle of the foils could change. Luna Rosa sailed on Tues with a gennaker they never deployed. Artemis is set to re-enter after their tragedy in May.

Sunday, Emirates found they sailed faster after jettisoning their jib.

Regardless of the nationality of the boat, most of the crews are Kiwis! And regardless of the team loyalty, a lot of them meet at The Ramp for "refreshments" after the debriefing. Sailors love camaraderie!

[garysanfran]

Two years ago, the AC45's began practicing for this AC race. I posted this before, but here it is again...Oracle's AC45 "Going Over" on The Bay...

http://www.bing.com/videos/search?q=...=0&FORM=NVPFVR

[ApS]

It was either I, OR the Webmaster that posted ON this forum an excellent video of the 2010 Oracle Trimaran "Flying" the center hull. I Searched here as well as YouTube and didn't find anything worthwhile. I found Some videos but NOT The GOOD one. NB

Catamarans have a built-in advantage over trimarans:

Originally Posted by garysanfran

Your boat could go over 60 mph?

One of my catamarans did go over 60-MPH—briefly—under just the mainsail!

It was that day a few years ago, that member DRH advised of 60-MPH winds in West Alton. It was a storm "cell" that was stronger here than West Alton. You couldn't see any waves at all—here, the entire lake surface was a great sheet of white foam.

It was one of those awful days when the woods sounded like a train passing.

It might not have been an issue had it not been for the fact I couldn't lower the mainsail. (Hobie-18 "hook-and-ring"). As a result, two shrouds pulled from their swages, and the mylar-coated mainsail got torn.

Luckily, no one was aboard at the time.

Originally Posted by garysanfran

I don't think the speed of these race boats is "restricted"! I never heard of limiting the "speed" of a race vehicle. The only limit I am aware of is wind speed when the race will be stopped for safety reasons. The wind on The Bay can easily get close to 30 mph and more.

I found out that the AC72s can "point" as high as the Olympic Tornado, so a one-on-one race wouldn't be competitive. But I can still sign up to race these guys, and I should be able to be declared the winner each day the winds exceed the AC72 maximum!



But the entire AC72 venue—though entirely "goose-bump-enjoyable" to me—can't compare to sailing races where the helmsman repeatedly drops from the wheel!

http://www.youtube.com/watch?v=X6L_pDroJiQ

(Just three minutes—no ads...)

[Par Four]

Is that picture for real? Geeze, I guess that guy really needed to hold that course? Was there contact?

Great photo though... I wonder if the sailing helmsman lifted the port side as an avoidance maneuver, or was he was already up on one side...

Would love to know 'the rest of the story'

[garysanfran]

Originally Posted by Par Four

Is that picture for real? Geeze, I guess that guy really needed to hold that course? Was there contact?

Great photo though... I wonder if the sailing helmsman lifted the port side as an avoidance maneuver, or was he was already up on one side...

Would love to know 'the rest of the story'

If you notice the port rudder of the cat is about 1' below and in front of the starboard bow rail of the committee boat. However the starboard hull seems to be further forward. There would have been a collision if this photo is real. Unless the cat could fly 1' higher on its starboard hull very quickly.

[ApS]

Originally Posted by Par Four

Is that picture for real? Geeze, I guess that guy really needed to hold that course? Was there contact?

Great photo though... I wonder if the sailing helmsman lifted the port side as an avoidance maneuver, or was he was already up on one side...

Would love to know 'the rest of the story'

The watermark "van der wal photo gallery" tells me it's real, all right. Professional photographer Onne van der Wal, Newport, RI, has taken the best action shots of sailing anywhere—worldwide—for at least two decades. A career devoted to traveling to regattas around the world—what a gig, huh?

Since the upwind position at the start is so-o-o-o important in sailboat racing, I'd expect this scene to be repeated at many catamaran contests, with the size of the committee boat being a variance.

Trimarans could also "fly a hull" over the committee boat, but I think this one's going over.



This particular photo—below—is from an advertisement, but there are many other similar photos on the Web.

(The "1" at bottom-center is the leading edge of the downwind hull).

[garysanfran]

I believe today's race, 3p.m. EST, will have Kiwis vs. Italians. The fog is currently lifting off The Bay. Armetis is scheduled to start Aug. 6th.

[AkwaMarina]

Originally Posted by garysanfran

I believe today's race, 3p.m. EST, will have Kiwis vs. Italians. The fog is currently lifting off The Bay. Armetis is scheduled to start Aug. 6th.

Do you know what channel (HD) it is on? Metrocast Laconia?

I know a certain sailboat bar that would nice to sit and watch the race at

[garysanfran]

Originally Posted by AkwaMarina

Do you know what channel (HD) it is on? Metrocast Laconia?

I know a certain sailboat bar that would nice to sit and watch the race at

Not sure. I'm in San Francisco and get it on an obscure channel call COZI (which I think is an NBC affiliate). You can also watch the race live, and the past,archived, races here...

http://www.youtube.com/AmericasCup

Bring a laptop to the bar and connect HDMI. Where is there a bar for sailors?

[garysanfran]

Could you imagine seeing one of these 13 story tall cats traveling 50 mph on Lake Winnipesaukee? What a sight to imagine!

[garysanfran]

This may help...

http://www.nbcsports.com/tv-listings...zccSubmit.y=11

[ApS]

Developing the world's fastest sailboat—L'Hydroptère:



https://www.youtube.com/watch?v=36PRnNBuN9I

We discussed "modern" powerboat foils nine years ago:
http://winnipesaukee.com/forums/show...ighlight=foils

Originally Posted by garysanfran

I don't think the speed of these race boats is "restricted"! I never heard of limiting the "speed" of a race vehicle. The only limit I am aware of is wind speed when the race will be stopped for safety reasons. The wind on The Bay can easily get close to 30 mph and more.

Your boat could go over 60 mph?

A Tornado-20 doesn't need to go 60 to be competitive: here's an account of a race where a Tornado "slips-in"—starting last—just to see how he'd do against much more powerful multi-hulls.



(Beating "Afterburner", a 52-foot racing machine, with an 80-foot mast!)

"...The great conditions seemed to continue as I made my way to the midpoint of the backside. Then I spotted a big sail at the far end...it was Afterburner! I could not believe I was actually on the same leg within visual range as this awesome speed machine..."
http://www.thebeachcats.com/news/70/...-anacapa-race/

[Orion]

I'm surprised we don't see some of these on the Lake.....



https://www.youtube.com/watch?v=gK60RZDtnT8

[ApS]

http://tinyurl.com/n865p4t

[ApS]

Originally Posted by Orion

I'm surprised we don't see some of these on the Lake.....



https://www.youtube.com/watch?v=gK60RZDtnT8

It's January, so the Moth class has completed their 2015 World's Cup Championship races "down-under". With 150 entrants, they were greeted by perfect sailing conditions—sunny, windy—up to 25 knots—and what they call—"calm seas".

https://www.youtube.com/watch?v=hH-C...layer_embedded

[webmaster]

With teams already at work in Bermuda it's time to start getting excited about the 2017 Americas Cup. Here's a great video a friend sent to me.

Karim: Amazing Technologie #Speedracer

Posted by Karim Maataoui on Saturday, May 16, 2015

[salty dog]

I'm also looking forward to watching the races. It's amazing to see the foils in action; hard to believe how the sport has evolved so quickly. As much as I enjoy the action, there's still something beautiful in watching a 12 meter cut through the water with the lee rail buried!

[ApS]

Originally Posted by NoBozo

Catamarans with daggerboards ..the normal ones anyways, Always retract the "windward" daggerboard to eliminate "drag" on that side. The submerged board on the leeward side is all that is needed to prevent sideslip.

If the boat, (again..a normal one) is sailing Off the wind, ie..Tacking Downwind, quite often... Both boards will be retracted. NB

Not every catamaran.

The Stiletto was manufactured with a daggerboard in its centerline.



The "factory" restorers in Nokomis, FL, occasionally get a request to put a daggerboard in each hull. The Stiletto was an impressive boat in three sizes; so impressive, enthusiasts have made it a business to professionally restore them in Nokomis, FL. Some buyers of the Stiletto-30 have requested that "cruising" equipment be stripped off to reduce it to the racer-weight it really was designed to be.

I'd never seen the Stiletto before seeing one off Rattlesnake Island, but that could have been 20 years ago. Probably a Stiletto-23, they were also manufactured in 27 and 30' lengths. (Stiletto-30, below)



I believe I have a photo of it, which helps me remember that it was white in color with orange trim. About that time, New Hampshire began the requirement to register unpowered sailboats. Where is it now?



Below is a brochure I acquired at the Nokomis "factory", with my handwritten notes. I decided to buy a Tornado-20 instead, but today am re-considering the Stiletto-30 without cruising equipment.

[BroadHopper]

There was a business man by the name of John Knox who had a Stiletto when he owned the camp next to me. It had sleeping qtrs. below deck and I believe it was the 27. It was pretty impressive to see him out on The Broads on a windy day. He sold the place in the late '70's and moved to the cape.

[ApS]

Disappointed in the showing of Sweden's Artemis, the editors of Sweden's Search magazine decided on their kind of "winter fun" by putting their Hobie on foils.

"We put foils on a Hobie Tiger F18 and started to try foiling in late November, with 2 degrees Celsius and 16-18 knots of wind. On the second test session we manage to get some good foiling and the top speed reached 32.1 knots. [39.1-MPH]

"We started with foils on daggerboard and rudder originally designed for a lighter boat, eventually the rudder foil broke but the boat continued to fly. After 30 minutes of sweet flying around feeling like the Kiwis the daggerboard foil broke as well and the fun was over.

"Repairs and reinforcements of the foils are already started and if the ice doesn’t prevent us from sailing, we will try to go flying again during the winter."

http://www.catsailingnews.com