AC 36 Foiling Monohulls

CT luv the double cultural reference

 

I get the feeling that double luff mainsails are in the same boat (so to speak…). There's a Lewis Francis Herreshoff* patent from 1925 that seems to cover it, showing it goes back nearly 100 years. But so far it's not been successful. In practice, pocket luffs and wing masts seem to do the job well enough when paired with a single skin sail.

Perhaps a case of "I like your old remix better than your new remix". ;-)


* Son of the famous Captain Nathanael Greene Herreshoff, but seems to have worked independently of Herreshoff Designs, Inc.

 

I wonder about double surface mainsail internal air pressure : is an overpressure necessary, wishable ? If no air feeding at the leading edge, is there a risk of low pressure (at high apparent wind speed) between the two sails, and therefore a striction of the sails just after the mast, loosing the beneficial streamline ? Are canvas with either battens or non zero flexure caracteristic necessary at the leading edge ?

An academic paper on « Conceptual ideas on double surface sail inflated by dynamic pressure » was presented by Germans at the Innovsail 2013 conference, being the core part of first author Soren Bruns Diploma Thesis within TU Berlin and FutureShip Gmbh. https://www.linkedin.com/in/sören-brüns-48a91a72/

Second author Heikki Hansen is NZ and worked on sail development within the America'cup.

Excerpt from their introduction : « The concept is a double surface sail, which is to be inflated by the dynamic pressure at the leading edge of the profile. The fundamental principle is the same as used by paragliders and kites, where openings at the leading edge of the wing allow the air to “fill” the profile to give it a beneficial aerodynamic shape. »

But since then, I have not seen further development from FutureShip or academic.

The paper :
http://1089821995.n307483.test.prositehosting.co.uk/wp-content/uploads/2013/03/7-Hansen_thicksail_paper_revised.pdf

 

Heads Up: The end of March may bring answers to the degree to which the new AC boat will be one-design. I hope The Rule has lots of latitude but I think it will be closer to one design, unfortunately.

 

According to my opinion, the pressure in the middle is needy in the front part of the sail. When the chamber is tight, it can come from a single point of hypertension of wind at the top.

 

Jimmy back with Luna Rosa: America's Cup: Spithill changes teams >> Scuttlebutt Sailing News http://www.sailingscuttlebutt.com/2018/03/13/americas-cup-spithill-changes-teams/?utm_medium=email&utm_campaign=Scuttlebutt%205037%20-%20March%2014%202018&utm_content=Scuttlebutt%205037%20-%20March%2014%202018+CID_e34d5b610ae3cd4f7388ef0208a7bc63&utm_source=Email%20Newsletter&utm_term=Americas%20Cup%20Spithill%20changes%20teams
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Excerpt from catsailingnews.com story and interview:
The 38-year-old, a multiple world champion in fleet and match racing, is now hungrier than ever to win back the Auld Mug after losing out to Emirates Team New Zealand in 2017. Read Spithill’s first interview since the news broke:

- How does it feel to reunite with Luna Rossa Challenge after you helmed them to the Louis Vuitton Cup Finals at the America’s Cup in 2007?
It’s great to be back with Luna Rossa Challenge – I have a lot of great memories from the four years we spent in Valencia during AC 32, and this time I have been impressed with the tools, technology and people they have in place. It’s a great mix of experience, new energy and enthusiasm in an open environment – the makings of a great team.

You have a vast amount of experience and, presumably, a lot of learnings that you bring to the table?
Of course as a competitor you’re always learning, and since the last race of AC 35, I’ve been thinking every day about the America’s Cup. Naturally, you go over the previous campaign piece by piece, focusing on all the key moments and decisions during the four years. Lately I’ve been able to understand how a lot of the other teams operated, and that in itself is very educational.

Any conclusions?
Ultimately, two things stood out for me: trusting my instincts is key, and the hunger has only gotten stronger.

And speaking of your past experiences, your collaboration with Oracle Team USA resulted in some iconic sailing moments. When you look back at it, what comes to mind?
What an amazing ride, with some amazing people. Without Larry Ellison and Russell Coutts, there is no way I could have gotten to this point in my career. I’m fortunate to have been able to work alongside some of the most successful people in sport and business, and lucky to be able to call them good mates. I look forward to catching up with them in the future.

It’s been announced that the boat for America’s Cup 36 is an AC75 monohull. First thoughts?
The boat is going to be a beast. It reminds me of America’s Cup 34 and the AC72 foiling catamarans. Nothing like this had been done before, and this boat is on the cutting edge of technology. There are a lot of unknowns with the AC75, which will push people to the limit and really challenge all the teams involved. However, this challenge and difficulty is really appealing, and I’m really excited to be back in the game.

And what are your thoughts about moving to Italy?
Last time with Luna Rossa challenge it was the Valencia campaign and we moved straight to Spain – this time I’m looking forward to living in Italy. Personally, I’ve had a lot of success racing and competing in Italy, and lifestyle and especially the food are awesome! I love the Italian culture, the landscape and the people. I have to admit, though, that I will need to work on my Italian.

Speaking of the culture, time for some quick-fire questions . . .

Your favourite Italian dish? Margherita bufala.
Pasta or pizza? Both.
Your favourite gelato flavour? Stracciatella.
Can you swear in Italian? Exceptionally well!
Your favourite Italian phrase from what you can speak of the language so far? Va bene.
Your favourite Italian football team? Juventus.
Public transport or Ferrari? Ducati.
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The end of the movie is interesting.
Los barcos del futuro volverán a ser veleros https://elfuturoesapasionante.elpais.com/los-barcos-del-futuro-volveran-veleros/

 

From Pressure Drop forum:
New York Yacht Club and Bella Mente Quantum Racing to Compete as "New York Yacht Club American Magic" in their Challenge for the 36th America's Cup

NEW YORK, March 27, 2018 /PRNewswire/ -- The New York Yacht Club and Bella Mente Quantum Racing Association ("BMQRA"), today announced they will compete under the name "New York Yacht Club American Magic" ("American Magic") in their challenge for the 36th America's Cup to be held in New Zealand in 2021.
Philip Lotz, Commodore of the New York Yacht Club, said, "'America'" was the first boat to win the America's Cup in 1851. 'Magic' was the first boat to defend the Cup in 1870. American Magic builds on the legacy of those two yachts, and the name embodies the mission of our campaign, which is to win the Cup and in the process build the foundation for a stronger competitive sailing culture in the United States. The New York Yacht Club is very excited to be part of this campaign and the legacy we are striving to create."
Over the coming months, American Magic will continue assembling a team of top sailing talent, and best-in-class designers and engineers to best position it to bring the America's Cup home to the United States and the New York Yacht Club. As it builds its world class team, American Magic will continue to leverage its partnerships with US Sailing and Oakcliff Sailing to develop the next generation of American sailors, reenergize the passion of fans and make the America's Cup relevant to the broad base of American sailing.
Hap Fauth, CEO of American Magic, said, "On behalf of Doug DeVos, Roger Penske and all the members of our team, it is an honor to represent the New York Yacht Club, its membership and the American yachting community in the 36th America's Cup as American Magic. Under this proud name, we are focused on creating an America's Cup culture in American sailing, and with our partnerships, we are engaging with the grassroots to increase the competitiveness of our sailors, and working to engender the kind of excitement the America's Cup previously enjoyed in the United States. We're not just racing to bring the Cup back to America, we're racing to bring American yachting back to the Cup."
Doug DeVos, Principal of American Magic, said, "As an avid sailor and passionate supporter of the NYYC, I'm thrilled to be a part of such an extraordinary team. Over the years, we have worked hard to promote sailing in the United States and inspire the next generation of sailors to compete at the highest levels of our sport. It's an honor and privilege to be a part of American Magic's challenge to bring the America's Cup back home."
American Magic's design team is actively at work planning for the first of two AC 75 class boats, and preparing for the publication of the AC75 Class Rule at the end of March. At the same time, the American Magic's sailing team is currently training in Long Beach, Calif., for the Ficker Cup, which is the qualifier for the Congressional Cup. The team expects to establish its primary base in Newport, R.I., later this spring.
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About the New York Yacht Club
The New York Yacht Club was founded in 1844 when nine New York yachtsmen met aboard John Cox Stevens' yacht and a year later its original clubhouse was built in Hoboken, N.J. The Club's Annual Regatta was first run in 1845. The Club was the keeper of the America's Cup from 1851 to 1983, and it organized the first transatlantic race in 1866. The Club maintains two exquisite clubhouses, on 44th Street in the heart of New York City, known for its Model Room and extensive nautical library, and Harbour Court in Newport, R.I., which annually hosts some of North America's most prestigious sailing events, including the Annual Regatta, Race Week at Newport presented by Rolex, the Rolex New York Yacht Club Invitational Cup and the Queen's Cup. www.nyyc.org
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About New York Yacht Club American Magic
Formed in October 2017 by Bella Mente Racing, Quantum Racing and the New York Yacht Club, American Magic brings together two highly successful racing programs with one of the foremost yacht clubs in the nation, all with the shared vision of launching a campaign for the 36th America's Cup competition, reconnecting the American sailing base with sailing's premier event and elevating the quality of competitive sailing in the United States. The syndicate intends to develop and support a team that will participate in the America's Cup competition and the Challenger Selection Series competitions that lead up to it. American Magic is a recognized 501(c)(3) nonprofit organization.

 

"New York Yacht Club American Magic"...now that's a long name. American Magic sounds better. Looks like an ambitious plan they have. Anxious to see this whole thing ramp up for the big show down in Kiwi land.

 

Joseph, I still vividly remember taking the day off work to watch the last race of the '83 Cup and how much I was hoping Australia II could win! I was ecstatic when she did! I would never have imagined back then that I would support the New York Yacht Club-but I'm almost there-and a little Yankee Magic would be pretty damn cool!

 

They innovation and teams they pour into this event are mind boggling. I wish other sailing races used their high tech race television graphics. With all the drone & minicam technology I can see a new industry popping up to address that. This sport needs improved TV coverage. It's as simple as that. I went to the AC team trials in Chicago a couple of years ago. Great event. The foil boats are just crazy fast. Reminded me of an air show.

 

These new boats are going to add a touch of HG Wells to the air show! Can't wait to see it....

 

The rules have been released, there are some interesting links at the bottom of the page: AMERICA'S CUP AC75 CLASS RULE REVEALED https://www.americascup.com/en/news/20_AMERICA-S-CUP-AC75-CLASS-RULE-REVEALED.html

Some other links
Early commentary (Italian): America’s Cup, le regole della barca monoscafo più veloce di sempre | | Il Secolo XIX http://www.ilsecoloxix.it/p/magazine/2018/03/28/ACPIdlTC-america_monoscafo_regole.shtml

Dan Bernasconi and Martin Fisher comments (video): 180329_AC75_Class_Rule_VNR.mp4 https://drive.google.com/file/d/1iIsXphybVsr1vZZF44m7PCl4CT3OpcT6/view

 

Super! Thanks.......
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Highlights of the AC75 Class Rule include:

• Strict limitations on the number of components that can be built including hulls, masts, rudders, foils, and sails, thus encouraging teams to do more R&D in simulation and subsequently less physical construction and testing
• Supplied foil arms and cant system to save design time and construction costs
• Supplied rigging
• One design mast tube

Too bad about #2 above- that seems to lock in the foil system and preclude development. Heading toward a one-design which, to me, goes against the whole AC premise from the beginning.
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Control Systems-from the Rule:

20.1 The adjustment of control surfaces, where permitted in Rules 14, 15, 18 and 19 must only be controlled
by crew:
(a) by direct contact of the crew on a control surface; or
(b) using one or more control systems.

20.2 No part of a control system may be capable of using feedback from the yacht state to control a control
surface, except:
(a) the extent of travel of a control function can be restricted by:
(i) ratchets, providing they are not controlled by an ECC or HCC; and
(ii) stops or locks, subject to Rule 20.3;

(b) one or more force input devices may be connected mechanically and/or through an HCC to a single
control surface; forces acting on that control surface can only be transmitted to those force input
devices;

(c) one or more force input devices may be connected mechanically and/or through an HCC to com-
mon mechanical drive trains or common pressure supply lines that provide power to multiple control
surfaces; forces acting on those control surfaces can be transmitted through those mechanical drive
trains or pressure supply lines to those force input devices;

(d) as permitted within an HCC by Rule 21.4 (d); and

(e) as permitted within an ECC by Rule 23.
---
For the avoidance of doubt, a control surface can move passively as the result of external forces.
20.3 Stops or locks acting on a single control function may be permanently in place (e.g. in the case of end
stops on a hydraulic actuator), or if not permanently in place, may only be engaged and/or disengaged:
(a) directly by the crew;
(b) through a mechanically connected force input device; or
(c) by an ECC and/or HCC, providing the device is only capable of locking the control function:
(i) in a maximum of two defined positions; or
(ii) from moving at all, regardless its position.

20.4 Stops or locks permitted by Rule 20.3 (c) shall not be combined to provide more control than two defined
positions, or to achieve the effect of indexed control.

20.5 Power that does work on a control surface to adjust its shape, position or orientation can only be supplied
by:
(a) external forces;
(b) the crew, via force input devices, only as expressly permitted in Rule 20.2;
(c) the FCS as permitted by Rule 26; or
(d) elastic energy less than 50 J stored within springs or lines (or collections thereof).

20.6 Power supplied by the crew to do work on a control surface must be used directly without being stored,
except where permitted by Rule 21.11 within HCCs.

20.7 Energy supplied by the crew to move control surfaces must primarily be transmitted through the crew’s
hands; any contact between other parts of the crew and force input devices must not transmit any signif-
icant power.

AC75 Class Rule v1.0 Page 38 of 62

20.8 One or more force input devicesthat are designed to allow more than one crew member to supply power
to a common mechanical drive train, a common pressure supply line or a common control function must
be grinding pedestals or winches that are operated by turning handles in a rotary motion with the hands.
This does not prohibit the use of other force input devices that occasionally allow more than one crew
member to provide simultaneous power (e.g. helm wheels), providing that is not their usual mode of
operation.

20.9 The use of flywheels or gyroscopes to store energy or mechanically stabilise the yacht is prohibited. Any
rotating mass on the yacht shall be no larger than required for its permitted purpose.