sail-world.com
 
 
News Home Cruising Photo Gallery Video Gallery
Sail-World.com : America's Cup: Oracle and Team NZ designers reveal AC72 secrets
America's Cup: Oracle and Team NZ designers reveal AC72 secrets

'Emirates Team New Zealand NZL5 practice before day eight of America’’s Cup 34.'    Chris Cameron/ETNZ©    Click Here to view large photo

For the past few weeks two designers from Oracle Team USA and Emirates Team New Zealand have been giving an almost two hour presentation in various venues around New Zealand, as part of the Institution of Professional Engineers NZ centenary celebrations.

Sponsored by leading New Zealand engineering consultancy, Beca, the free-entry presentation has travelled to six centres in the North and South Islands and has attracted packed houses.

The two design engineers Andy Kensington from Team NZ and Neil Wilkinson from Oracle, both graduates from New Zealand universities have been involved in America's Cup teams for 13 and 23 years respectively.

Kensington opened running through a few of the differences between AC72 technology and the earlier monohulls used in the America's Cup and looked at the canting keelboats. Then he turned to why Emirates Team NZ settled on the foiling concept from the outset.

The first reason was obvious - that it would be faster, and surprisingly given later events, foiling was also safer, noting that calculations showed that a conventional multihull of the AC72 type would be difficult in winds above 18kts, and even more so in a bear-away situation.

The difference between the two teams daggerboards is apparent in this image. -  Chris Cameron-ETNZ©   Click Here to view large photo

Emirates Team NZ took a multifaceted approach, building a 'waka' a non-sailing foiler which was towed on two North Island lakes, and then the more widely known SL33's on the Waitemata, before going full size in the AC72.

The full progression was shown in a series of video clips, including the SL33's being used to test basic concepts before switching to foilers, and then wingsailed foilers.

In a series of graphics Kensington demonstrated the component forces in a large foiling multihull constrained by the AC72 rule. He also touched on the effect of cavitation on hydrofoils, which influenced the section shape. Then they moved onto various permutations of foil trying to find the optimum between lift, drag and speed.

With the AC72 outed as a foiler, he compared Team NZ's first AC72 with the second, noting that the platform alone took 45,000 man hours and the wingsail a further 20,000 hours to build.

Downwind speed between the first and second boat moved from 35+kts in Boat1 to 45+kts in Boat 2. Upwind the top speed moved from 18+kts to 28+kts, with massive speed gains being made between the Louis Vuitton Final and the America's Cup Match.

Oracle Team USA was cleaner aerodynamically and featured a pod under the wingsail which had an end plate effect. ETNZ opted for a more conventional approach -  Chris Cameron-ETNZ©   Click Here to view large photo

Kensington put Oracle's comeback down to luck coupled with a dramatic increase in upwind VMG as well as tacking speeds and good starts. The difference between the two boats being revealed in one telling upwind image, where both boats are heading towards the camera. Oracle is clear of the water and foiling beautifully, but still getting maximum lateral resistance from her foils, while Emirates Team NZ is struggling to lift her leeward hull clear of the water.

For Oracle Team USA's part, Neil Wilkinson acknowledged that the team had gone into the 34th America's Cup with a head start in the technology stakes as a result of what had been learned in the 2010 America's Cup from the 120ft wingsailed trimaran they sailed to win in two races.

He elaborated on the engineering aspects of foils and the different way they worked upwind and down and also in the transition while gybing and tacking - plus how the foils are canted for up and downwind sailing

Wilkinson claimed that Oracle Team USA had been designed as a foiler from the outset, but broke a foil on the first day of sailing. After that incident, he built a test bed for foils, which consisted of a heavy steel flatbed onto which the foil was strapped before the expected load forces were applied of up to seven tonnes. The deflection of the carbon foil under load was staggering.

The most telling image of the 34th America’s Cup - Oracle Team USA have their boat foiling perfectly upwind and sailover Emirates Team New Zealand on the beat in race 18. America’s Cup 34. -  Chris Cameron-ETNZ©   Click Here to view large photo

He then turned to the construction of the foil cases and how these worked in the boat, with up and downhaul lines. OTUSA and ETNZ used different systems. They also differed int he layout of the boats, with Oracle Team USA opting for a more aerodynamically refined package with the crews being carried more in the hulls rather than the ETNZ approach that was to carry the crew more on the platform.

In another series of load diagrams, Wilkinson elaborated on the forces operating on the AC72s, particularly around the foil cases with a lift of about six tonnes, a lateral force of seven tonnes. At the boat end of the foil there is a staggering 22 tonnes at the pivot point of the foil and 16tonnes on the control ram at the top of the foil - all supported within the AC72 hull structure.

Wilkinson freely admitted that most of the initial design developments in the AC72 came from Team New Zealand while Oracle watched, copied and modified.

An example of this was the development of foils - where Oracle wanted to emulate the Team NZ shape and improve on it, but could not get the daggerboard close enough to the bottom of the boat when retracted, as required by the AC72 rule. So an ingenious 'sliding door' was fitted around the daggerboard slot in the AC72 hull to allow the daggerboard to move closer to the bottom the hull when retracted thus complying with the rule.

Wilkinson then moved onto the foil controls - handled through buttons on the steering wheel, with foil lift buttons on one site of the wheel and foil pitch on the opposite side of the steering wheel. Further controls were on four touch panel points in the opposite cockpit, plus a further set in the floor of one of the cockpits operated by one of the grinders.

Emirates Team New Zealand practice the first reaching leg before racing.safety was big factor in opting for foiling boats -  Chris Cameron-ETNZ©   Click Here to view large photo

While Oracle Team USA undoubtedly made many mistakes in the 2011-2013 campaign, the key issue was how the team understood what happened, learned from these and used the experience to improve the boat's performance. The team did have a very good, what he called 'forensic program' which allowed design engineers to analyse multiple data streams in a line graph format, to look for unexpected issues and be able to accurately draw conclusions as to cause and effect, reducing the chances of repeat errors, and creating a data platform for speed and boat handling development.

A couple of moments of truth for the US team were the nosediving incidents, the first of which wrecked the wingsail and almost completely destroyed the boat. The second had less dramatic results but was a significant learning experience. One of the tools used to analyse what happened in these incidents was a multiple moving plot of the data gathered from various key readout points, which would enable the forensic team to look at how the various elements interplayed, together with similarly time stamped video.

In the example shown a nosedive incident was triggered when the afterguard tried to adjust the foil pitch control using hydraulics, which at the critical moment had lost pressure. The readout showed that a wingsail twist adjustment was being done at the same time draining the hydraulic pressure to the point where the foil control failed to work - triggering some re-design work to avoid a re-occurrence of the issue. In fact four changes to the hydraulic system were made to avoid a re-occurrence of this situation

In the video, Wilkinson explains how the read-out analyse process worked and the information streams that can be correlated and understood.

The pitch control on the Oracle daggerfoil was one of the many controversies of the 34th America's Cup, being the subject of three Jury Hearings just a few weeks before the start of the Match itself. Wilkinson explained the adjustment system with a series of graphics and video.

Emirates Team New Zealand’s AC72, NZL5 runs race drills with Luna Rossa in their build up to meet Oracle Racing in the America’s Cup. 30/8/2013. -  Chris Cameron-ETNZ©   Click Here to view large photo

He went on to highlight the key differences between Oracle and Team NZ development campaigns being:

- Time on the water: Team NZ were launched and sailing before Oracle and stayed that way right through the campaign (Team NZ has 85 days on the water and performed 2000 tacks and 2000 gybes in this build up)

- Disasters: Oracle broke her foils on the first day, losing 5 weeks, and capsized on Day 8, losing 15 weeks

- Wings: Oracle had prior experience with the wingsail development from the 2010 America's Cup. ETNZ's main element wingsail twist was more complex than OTUSA's. However Oracle had tried the same setup and did not believe that it offered significant advantages.

- Foils: Oracle Team USA made a gain on ETNZ having slightly thinner boards with a thicker radius and more highly stressed.

- Daggerfoil Control system: Oracle used an electro-hydraulic system operable from either side of the boat. ETNZ used a mix of electro-hydraulics and manual systems.

Key differences which determined the Match

- Wing tune: Oracle improved upwind drive through increased lower aft loading. (interestingly this significantly increased the wingsail trim sheet loads, and the subsequent hydraulic demands required the crew to grind hard to maintain power from the race start to the finish)

- Crew work: Oracle mastered foiling tacks, gybes and upwind foiling. (While ETNZ led the way in the first two elements, the NZers admitted they never mastered upwind foiling to the extent achieved by Oracle)

-Board control: Oracle had improved positive positioning of the board pitch through electro/hydraulic systems development

- Rudder/Elevator refinement: Oracle added small anti-cavitation mods to the intersection of the elevators and rudder


by Richard Gladwell


  

Click on the FB Like link to post this story to your FB wall

http://www.sail-world.com/index.cfm?nid=122447

8:56 AM Fri 23 May 2014GMT


Click here for printer friendly version
Click here to send us feedback or comments about this story.

Click for further information on
2013 America's Cup

Related News Stories:

22 May 2014  America's Cup: Artemis death verdict 'result of an human act'
10 May 2014  A year after the Artemis incident, the sailors tell of the pain
01 May 2014  America's Cup: Oracle and Team NZ tech insights - Free lecture tonight
16 Apr 2014  America's Cup: Expected de Ridder penalty should be reduced
14 Apr 2014  America's Cup: Dean Barker's Blog - A sail with the Duke and Duchess
12 Apr 2014  America's Cup: Coutts claims ISAF Jury on a crusade, backs Kiwi report
10 Apr 2014  America's Cup: Two Kiwis escape hometown action in AC45 rules ruckus
03 Apr 2014  34th America's Cup: A Match of three weeks - Part 3 - Under the Pump
01 Apr 2014  34th America's Cup: A Match of three weeks - Part 1 - Regaining time
08 Mar 2014  Fast foils-a conversation with Paul Bieker, part two
MORE STORIES ...






News - USA and the World

2015 Hobie 16 North American Championships September 20 to 25 at Pensacola Yacht Club. ... [more]  

Hobie Mid-Winter East - Ocean Springs Yacht Club April 10-12 2015. The regatta is open to all Hobie Cat classes ... [more]  

Choosing the northern route turned out to be a brilliant tactical decision. But not all decisions went so well. Because of one wrong gybe and changed weather patterns, Team Brunel lost its lead in less than a day. With only the Volvo Ocean Race tracker as a guide, it’s difficult for fans to understand how the Dutch team lost more than 80 nautical miles. Skipper Bouwe Bekking looks explains ... [more]  

RORC Caribbean 600 – Arguably the best fleet of offshore racing yachts that has ever gathered in the Caribbean, took part in the seventh edition of the event. 66 yachts started the 600 mile race around 11 Caribbean islands, with numerous world champions, America's Cup and Volvo Ocean Race sailors taking part with passionate Corinthian amateurs, many of whom are members of the Royal Ocean Racing Cl ... [more]  

This summer’s ‘must have’ tickets for The America’s Cup World Series, Portsmouth (ACWSUK) are officially available from Monday 2nd March. Fans and spectators are encouraged to book their place now to avoid disappointment with event organisers already receiving a large number of ticket and hospitality enquires. ... [more]  

SCYA's E.E. Manning Regatta 2015 – They had never sailed together until six months earlier when they stepped onto a boat that neither had ever sailed, but skipper Joseph Hou, 15, and crew Skylar Jacobsen, 14, squeezed out a remarkable victory Sunday in the Southern California Youth Yacht Racing Association's Shadden Series ... [more]  

Shawn Bennett of Tiburon, Calif. won the Long Beach Stop of the 2015 California Dreamin’ Series Sunday in this International Sailing Federation (ISAF) Grade three match racing regatta hosted by Long Beach Yacht Club and raced on the Long Beach Sailing Foundation’s fleet of Catalina 37s. ... [more]  

Sitting here in Antigua airport waiting for my flight back to London, life is good having just blasted across the Atlantic in just under nine and a half days on board the new Phaedo3 MOD 70, one of the fastest sailing boats 'in the world'... ... [more]  

In November of 1994 Yachting Magazine consultant Gary Jobson asked Peter Craig, 'how hard can it be? Just raise some flags and blow off some guns.' And so began Craig's involvement in what was then a 112 boat - single division regatta that would soon evolve into an iconic annual international keelboat event. Yachting Magazine founded Key West Race Week in 1987. ... [more]  

Serious Fun! That's what participants, sponsors and onlookers are expected to have during the 35th St. Maarten Heineken Regatta which will be held in St. Maarten during March 05 - 08, 2015. The Regatta is considered to be the biggest in the Caribbean and offers a great combination of challenging races and fantastic gatherings under the banner of 'Serious Fun'! ... [more]  

Barcelona World Race – After the limits of the southern oceans imposed by the combination of the weather systems and the safety barrier of the Antarctic Exclusion Zone, the Atlantic is opening up for the top trio. ... [more]  

Images from Auckland of the media conference on Sunday and prizegivings for Leg 4 ... [more]  

At the media conference held the morning after the finish of leg 4 of the Volvo Ocean Race, Mapfre skipper Xabi Fernandez announced that regular skipper Iker Martinez will be back on board for the next leg and most of the remainder of the race. Fernandez had taken over the role, skippering Mapfre to a 4th place on Leg 3 and a win on Leg 4. ... [more]  

Miami Sailing Week (BMSW) presented by EFG Bank will kick off with 173 boats traveling to Coconut Grove to compete in the 88th Bacardi Cup ... [more]  

Volvo Ocean Race: Leg 4 finishes at night after a tense day *Feature by Richard Gladwell, Sail-World.com NZL
The finish was more like that of a short 100nm race around the Hauraki Gulf. Instead, the first three boats to cross the finish line at the end of Leg 4 of the Volvo Ocean Race arrived mid-evening. ... [more]  

Farr 40 International Circuit - Alex Roepers doesn't like to dwell in the past. However, when prompted, the New York businessman will talk about the magical run he and the crew aboard Plenty enjoyed during the 2014 Farr 40 International Circuit. To the contrary, the thrill of victory only made Roepers and the Plenty team hungry for more. ... [more]  

Coast Guard crews continue the search Monday for Richard Byhre, the 76-year-old sailor who did not return from his sailing trip as expected. ... [more]  

The International Sonar Class is pleased to announce that Shumway Marine, with the cooperation of designer Bruce Kirby has made arrangements to have the Sonar built by Rondar Race Boats in the U.K., with plans eventually to have the boat built on both sides of the ocean. The American Rondar facility is in Peabody, MA. Rondar, expects to launch its first Sonar in April. ... [more]  

Rio de Janeiro's state environmental agency says it is investigating a fish die-off that has left thousands of carcasses floating in waters where sailing events are to be held when Brazil hosts next year's Olympics. ... [more]  

This year's 35th edition of the St. Maarten Heineken Regatta is nothing less than an island-wide effort. Besides the sponsors, countless volunteers and the numerous local organizations that offer their excellent services, the Regatta Organizers would like to say special thanks to the hotels which are so generous to donate complimentary hotel rooms for the St. Maarten Heineken Regatta. ... [more]  

Volvo Ocean Race: Images ashore after Leg 4 by Richard Gladwell, Sail-World.com NZL
Sail-World's NZ Editor, Richard Gladwell, was on the water and ashore for the finish of Leg 4 of the Volvo Ocean Race, and provided this gallery of images after the first three boats had docked. ... [more]  

Volvo Ocean Race: Images from the finish of Leg 4 by Richard Gladwell, Sail-World.com NZL
Sail-World's NZ Editor, Richard Gladwell, was on the water for the finish of Leg 4 of the Volvo Ocean race, and captured these images from the final few miles of the race, and on the dock. ... [more]  

O MAPFRE conquistou de maneira emocionante a quarta etapa da Volvo Ocean Race, disputada entre a China e a Nova Zelândia. Na manhã deste sábado (28), o barco espanhol cruzou a linha de chegada em primeiro após quase 21 dias de navegação. ... [more]  

RYA Suzuki Dinghy Show - a British tradition by Rob Kothe and Jedda Murphy
Our favourite boat show in the whole world is the RYA Suzuki Dinghy Show. It is like no other, with a large percentage of eight to 15-year olds, with many young siblings often dragging their parents down the aisles. Its a dull overcast day in Lonon with rain showers, but inside the heated halls of the Alexandra Palace, the fabled 'Ally Pally' , around 5,000 visitors will gaze at touch and feel ... [more]  

MAPFRE (Xabi Fernández/ESP) emerged victorious despite a pair of major setbacks in Leg 4 following one of the tightest-fought finishes in Volvo Ocean Race history on Saturday night. The victory gives the 2014-15 edition its fourth winner in four legs following successes for Abu Dhabi Ocean Racing (Ian Walker/GBR), Team Brunel (Bouwe Bekking/NED), and Dongfeng Race Team (Charles Caudrelier/FRA). ... [more]  

Mapfre took the gun, Abu Dhabi Ocean Racing was second and Dongfeng third. Photographer Ainhoa Sanchez was in the air over Auckland for 2014 – 2015 Volvo Ocean Race, and provided these images. ... [more]  

Photographer Ainhoa Sanchez was in the air as the fleet approached Auckland for the end of leg 4 for the 2014 – 2015 Volvo Ocean Race, and provided this gallery of images. ... [more]  

The wind has switched half turn and boats are now beating upwind to the finish, MAPFRE has held their lead and with the change in direction look quite safe. Team Alvimedica who was catching up at speed has slowed right up, caught in light winds behind Tiritiri Matangi island. With less than 10nm to go to finish and a fair 10kt wind holding, the slow patch looks to have been removed from equation ... [more]  

2015 RORC Caribbean 600 - Hap Fauth's American JV72, Bella Mente has been declared the overall winner. Whilst several yachts are still racing, by the morning of Friday 27th February none of the remaining teams had the ability to better Bella Mente's corrected time under IRC. It was third time lucky for Bella Mente as the Maxi 72 has finished second overall for the past two years. ... [more]  

Catch the live coverage of the Leg 4 Finish in Auckland. Check the video timer for a countdown to the start of coverage and the expected race finish time. Sail-World is updating the on the water action and weather - which has compressed the lead four boats ... [more]  

Racing in second place in the Barcelona World Race, the Barcelona sailor Guillermo Altadill and Chilean José Muñoz passed Cape Horn (67° 17' 35 W) this morning at 2h12 UTC (3h12 am in Barcelona, 11h12 pm of the 27th of February in Chile), after 58 days, 14 hours and 12 minutes of racing since their start from the Catalan capital on 31 December 2014. ... [more]  

On Sunday March 8th 2015, the St. Maarten Heineken Regatta will close out the final night of music with one of the most distinctive performances to date. DJ Natty Rico will be the final act to grace the regatta stage during the 'Legendary Party' following Kool and the Gang. His unique blend of saxophone playing and DJ skills will have your jaw dropping in amazement. ... [more]  

Barcelona World Race - Cape Horn beckons for second and third placed Neutrogena and GAES Centros Auditivos. While the two IMOCA 60s are expected to pass at speed with around six hours of separation, in what might be considered favourable conditions for one of the most inhospitable and complicated corners of the Barcelona World Race, amidst the long hours of stress and fatigue ... [more]  

Big winds for SCYA Manning Regatta at ABY Club
Hutchinson and Roble honored at US Sailing’s Rolex Awards ceremony
Finn World Masters Championships 2015 - Pre registration open
Registration for the 2015 Finn European Championship is live!
RORC Caribbean 600, day 4 – Classic Focus and Four Figaro II teams
Hutchinson, Roble honored in New York as Best of 2014
Barcelona World Race - Pedestrian Pacific, Atlantic highway to home
America's Cup: Artemis Racing lines up against Oracle Team USA - Video
High Performance Yacht Design conference during Volvo OR stopover
Volvo Ocean Race: Ryan Houston - How Alvimedica's chemistry works *Feature
Volvo Ocean Race: Dave Swete - Alvimedica's race so far *Feature
Volvo Ocean Race 2015 – No sleep until Auckland
Etchells NA Midwinter East Series - Schoonmaker Cup preview
RORC Caribbean 600 day 4 – Close competition – 43 yachts still racing
Volvo Ocean Race: Team Alvimedica hopes to use Coastal Classic tricks *Feature
AC45 Turbo Training - Oracle Team USA images by pressure-drop + Video
America's Cup: Emirates Team New Zealand gears up on less money *Feature
Volvo Ocean Race – The race tightens as New Zealand looms
AWT Goya Pro Cabo Verde kicks off in style!
Barcelona World Race - Two different worlds separated by Cape Horn
America's Cup: Barker offered non-sailing role by Emirates team NZ   
2015 CYC Midwinters Race – Pictures by pressure-drop.us   
CYC Midwinters Racing – Bring On The Breeze! – Overall   
Laser World Championship – Over 2000 sailors to race in Kingston   
Volvo Ocean Race: Barkow and Lush - from the Olympics to the Volvo *Feature   
Volvo Ocean Race 2015 – Its anyone's race - Leg 4 to Auckland   
Barcelona World Race - A time for extra care and caution   
2015 RORC Caribbean 600 - Phaedo3 breaks record   
Barcelona World Race - Cheminées Poujoulat pass Cape Horn   
2015 RORC Caribbean 600 - Records predicted to tumble + Video   
2015 ISAF Women’s Match Racing World Championship - NOR released   
Asher Otto and Itchy Feet to open up the Caribbean Jam night   
RS Sailing and BIC Sport North America team up for sailing programs   
RORC Caribbean 600 – Record pace on Day 2   
Port of Los Angeles Harbor Cup - About to begin   
10 tips from BoatUS for owners and renters   
Aquece Rio International Sailing Regatta – Notice of Race online   
2015 CYC Mid Winters images by h20shots   
Adventures of a Sailor Girl: News and interviews from February 23 show   
Volvo Ocean Race: Ryan Houston looking forward to his Kiwi home   


For this week's complete news stories select    Last 7 Days
   Search All News
For last month's complete news stories select    Last 30 Days
   Archive News







Sail-World.com  


















Switch Default Region to:

Social Media

Asia

Australia

Canada

Europe

New Zealand

United Kingdom


http://www.sail-world.com/event_images/image/Twitter_logo_small.png http://www.sail-world.com/event_images/image/FaceBook-icon.png  http://www.sail-world.com/event_images/image/RSS-Icon.png

United States

Cruising Northern

Cruising Southern

MarineBusiness World

PowerBoat World

FishingBoating World

 

Contact

Commercial

News

Search

Contact Us

Advertisers Information

Submit news/events

Search Stories/Text

Feedback

Advertisers Directory

Newsletter Archive

Photo Gallery

 

Banner Advertising Details

Newsletter Subscribe

Video Gallery

Policies

 

 

 

Privacy Policy

 

 


Cookie Policy

 

 



This site and its contents are © Copyright TetraMedia and/or the original author, photographer etc. All Rights Reserved.  Photographs are copyright by law.  If you wish to use or buy a photograph contact the photographer directly.
XLXL NEW US
LocalAds   DE  ES  FR  IT