samedi 16 juin 2012

AMERICA'S CUP - HISTORY OF THE MULTIHULLS Part II- HISTOIRE DES MULTICOQUES 2éme Partie - THE ANCESTORS of the AC72 - LES ANCÊTRES DE L'AC72

LA SAGA DES MULTICOQUES



Le 5 juin dernier nous avions ouvert pour vous le "livre" des origines...
Désormais, les multicoques font partie de la plus exceptionnelle course du monde de la voile et en septembre 2013, à San Francisco, nous assisterons à un spectacle unique ! 


Récemment, nous vous avons montré que, dès 1877, les eaux baignant les côtes californienne avaient déjà été sillonnées par un étonnant catamaran, Duster ! La photo montrant cet engin croisant devant le San Francisco Yacht Club est pour le moins surprenante.


111 ans plus tard, le catamaran de Dennis Conner, Stars & Stripes US-1 (1988) disputait une bien curieuse America's Cup et écrasait le Big Boat KZ-1 du Néo-Zélandais Michael Faye. Toujours en Californie, mais plus au sud cette fois, à San Diego.


Dans l'intervalle, l'histoire des multicoques modernes prenait son envol.


Voici le second volet de cette passionnante saga.


Bonne lecture

François Chevalier & Jacques Taglang




Si les pirogues doubles, praos et trimarans sont nés il y a plusieurs milliers d’années en Océanie, le premier catamaran occidental a été construit en Angleterre, par  William Petty en 1662. Mais le vrai catamaran de course moderne est dû au plus génial architecte de l’histoire de la plaisance, l’américain Nathanael G. Herresoff. Les extraits de son commentaire paru dans le New York Herald du 16 avril 1877, valent la peine d’être cité :

"À la fin de l’année 1875, je réfléchissais maintes fois comment augmenter la vitesse d’un monocoque. Je pensais que pour avoir plus de vitesse, il fallait plus de puissance ; mais avec plus de voilure, vous devez augmenter la largeur de la coque, et plus la largeur augmente, plus le périmètre de la maîtresse section augmente, et donc aussi la surface de friction."

"Ainsi, on se trouve en présence de deux facteurs de vitesse qui s’opposent. Ce qui nous donne un gain d’un côté correspondant à une perte de l’autre. Aussi, la première chose à trouver est donc de diminuer la surface en conservant la stabilité ; le bateau aurait de la raideur à une certaine distance de l’axe de la quille, où il aurait une grande efficacité. Je conservais ce principe ; remontant la quille de plus en plus haut, jusqu’à ce qu’elle sorte de l’eau, et que, surprise ! c’était devenu un catamaran."

"Il n’y a rien d’autre à faire que de prendre une scie et de couper le bateau en deux, les séparer, couvrir le tout d’un pont et vous y êtes !"

Mais Herreshoff ne s’arrête pas là :
Les catas des Herreshoff
©François Chevalier 2012
"J’abandonne alors l’idée de ma coque malade avec son creux au milieu et lui substitue deux longues coques fines et légères, reliées à l’avant, au milieu et à l’arrière."

Dans cette démarche où l’architecte réinvente le catamaran, il est troublant de voir que le catamaran ne s’impose pas comme concept - les récits des navigateurs des siècles précédents sont tous très clairs sur la vitesse et l’efficacité de ce type de voilier – mais découle d’une réflexion sur l’amélioration des performances du monocoque.
©François Chevalier 2012


À partir du monocoque (1), Herreshoff augmente le bau pour augmenter la raideur (2), puis commence à remonter la quille pour obtenir plus de volume sur l’extérieur (3), jusqu’à ce que la quille sorte de l’eau (4). Il suffisait de couper le bateau en deux et d’écarter les morceaux (5), mais il semble évident qu’il vaut mieux deux coques fines (6).

Dans les colonnes de The World du lendemain de la régate du Centenaire des Etats-Unis, le 24 juin 1876, on pouvait lire :
"Le catamaran Amaryllis, construit par Mr Herreshoff de Providence, a survolé tous ses concurrents le long de Long Island, passant l’un après l’autre les yachts en course comme s’ils étaient encore à l’ancre. Alors que Amaryllis s’élançait en vainqueur sur la ligne d’arrivée, le catamaran a été salué par les coups de canon des yachts ancrés autour de la ligne et par les cris d’acclamation des spectateurs à bord des steamers d’excursion, en l’honneur de cette victoire."

L’éditorialiste titrait alors : Un yacht révolutionnaire !
"Hier, personne n’a protesté contre son inscription aux régates, probablement pour la simple raison que chacun pensait le battre, mais maintenant, tout le monde semble très contrarié d’avoir été battu.
Quoi qu’il en soit, il appartient désormais aux propriétaires des grandes goélettes de se concerter, car quelqu’un pourrait construire un super Amaryllis de cent pieds (30,48 m), qui risquerait de transformer leurs yachts en un paquet de bois inutile. C’est un sujet tout aussi important que celui de défendre la Coupe de l’America…"

Le sujet précédent pouvait sembler assez éloigné de l’actualité de la Coupe de l’America, même si on peut y trouver quelques similitudes dans la variété des formes des coques et des voilures de ces pirogues océaniennes, la question de l’avenir de la Coupe est posée dès cette première journée mémorable. Pour mémoire, cent douze ans plus tard, Dennis Conner défendait la Coupe avec un cata…



Parus dans American and British Yacht Designs en 1992, (second ouvrage de référence de François Chevalier et Jacques Taglang - toujours disponible, voir la promotion dans le blog), les plans de forme et de voilure de John Gilpin (1877) mettent en évidence les subtilités de construction des catamarans d’Herreshoff. Il ne s’agit plus seulement de deux coques fines, mais d’un assemblage sur rotules et tendeurs complexe qui ont rendu finalement ces voiliers assez coûteux.
©François Chevalier 1992



Il est intéressant de reprendre la démarche de l’architecte, et de s’arrêter à son stade (4), là où il parle de remonter la quille au dessus de l’eau, sa fameuse coque "malade". Or, en 1898, soit 23 ans plus tard, l’architecte canadien G. Herrick Duggan cherchait à réduire la surface mouillée de son One-tonner pour défendre les couleurs de son club dans la Seawanhaka Cup. La Jauge ne prenait alors en compte que la longueur de flottaison. Aussi, les élancements devenaient vertigineux, et dès que la coque gîtait, la flottaison s’allongeait de la longueur totale du bateau, le pont devenant de plus en plus rectangulaire pour bénéficier de cet avantage.

Avec Dominion, Duggan crée une double coque en remontant la ligne de quille et réduit de 30 % la surface mouillée, et remporte facilement la coupe ! Devant la colère des concurrents, la jauge est modifiée pour la coupe suivante et désormais, la quille devra être le point le plus bas. Cela n’empêche pas l’architecte B. B. Crowninshield (1867-1948), connu pour ses extravagances, de concevoir, en 1902 une plateforme avec une carène de trimaran. Hades ne pourra rien faire contre la création de Starling Burgess, Outloook, le plus extrême des scows, mais cela est une autre histoire…

Le plus important de cette aventure reste que les catamarans ont failli envahir le yachting par deux fois, en 1876 et en 1892, essais non transformés à cause de modification de réglementation.
©François Chevalier 2012
François Chevalier 1992



Dominion, 10,85 m pour 5,28 m à la flottaison, est un développement du scow. En remontant la quille au-dessus de l’eau afin d’augmenter la raideur et de diminuer la surface mouillée, l’architecte crée un catamaran.



Hades, 16,75 m pour 6,40 m à la flottaison, est un faux trimaran, la quille centrale est là juste pour détourner la règle de jauge qui impose qu’elle doit se trouver au point le plus bas des sections. La plateforme est tellement fine qu’elle est raidie par une structure tendue sur le pont.

Si le multicoque ne connaît pas de succès, il ne sera jamais pour autant abandonné. Sur les registres des voiliers aux Etats-Unis, il y a toujours eu une dizaine de catamarans de course ou de croisière.
Dans son ouvrage Common Sense on Yacht Design publié en 1948, le fils de Nathanael G. Herreshoff, L. Francis Herreshoff (1890-1972), déplore que la polémique dont a été victime son père en 1876 a créé un vide par rapport au développement des voiliers rapides. Dans son chapitre consacré à l’avenir de la voile (The Sailing Machine), il propose plusieurs catamarans, dont le Catamaran du Futur, avec des coques de bateau à moteur et deux ailes pivotantes orientables en guise de voile tenues sur un mât quadripode.
©François Chevalier 2012



Le Catamaran du Futur, "Sailing Machine" est un projet de L. Francis Herreshoff dessiné en 1948. Si le fils Herreshoff excellait dans la représentation en architecture navale, il ne manquait pas non plus d’imagination !

©Fraçois Chevalier 2012
©François Chevalier 2012
Plus prosaïque, mais plein d’idées reprises quarante ans plus tard, Sailski est un catamaran - toujours dessiné par L. Francis - pour la construction amateur et dont les plans ont été publiés dans la revue The Rudder de mai 1949 à février 1950. Construits à trois exemplaires entre 1952 et 1966, ses coques dissymétriques faisaient office de plan anti-dérive et la pression du mât sur le bras avant était soulagée par un gréement rigide. Le bipode et les bras étaient profilés. C’était le premier cata avec un trempoline entre les coques. Leurs équipiers ne faisaient pas encore de galipettes pour changer de bord, comme sur certains AC45 aujourd’hui !


Francis Herreshoff a répondu à la demande des lecteurs de la revue The Rudder qui désiraient un catamaran léger, facile à construire, rapide et bon marché. Il conçoit alors Sailski, un catamaran assez original de 27 pieds.

Ce qui nous mènera dans le prochain chapitre au développement des catas de plage…

Texte : François Chevalier

Fiches techniques :


John Gilpin
Catamaran
Architecte : Nathanael G. Herreshoff
Chantier : Herreshoff Mgf.
Mise à l’eau : 1877
Longueur : 9,75 m
Flottaison : 9,37 m
Bau : 5,28 m
Tirant d’eau : 0,50/1,26 m
Déplacement :  1,5 t
Voilure au près : 85 m2

Dominion
1 tonneau, Seawanhaka Cup
Architecte : G. Herrick Duggan
Mise à l’eau : 1898
Longueur : 10,83 m
Flottaison : 5,28 m
Bau : 2,31 m
Tirant d’eau : 0,28/1,70 m
Voilure au près : 45 m2

Hadès
Trimaran hybride, Quincy Cup
Architecte : B. B. Crowninshield
Mise à l’eau : 1902
Longueur : 16,75 m
Longueur hors tout : 22,40 m
Flottaison : 6,40 m
Bau : 5,18 m
Tirant d’eau : 0,36/2,5 m
Voilure au près : 185 m2

Sailing Machine
Catamaran à voilure rigide, en ketch
Architecte : L. Francis Herreshoff
Projet 1948
Longueur : 9,15 m
Flottaison : 8, 85 m
Bau : 5,35 m
Tirant d’eau : 0,67/1,15 m
Surface de voilure : 44 m2

Sailski
Catamaran, construction amateur
Architectes : L. Francis Herreshoff
Mise à l’eau : 1952
Longueur hors tout : 8,23 m
Longueur de flottaison : 7,33 m
Bau : 4,71 m
Tirant d’eau :  0,20/0,93 m
Surface de voilure : 23 m2

AMERICA'S CUP - COUPE DE L'AMERICA - 34TH CUP - 34e COUPE - MULTIHULLS - MULTICOQUES - TRIMARAN - CATAMARAN - USA 17 - AC72 - US-1 - 60'ORMA - MOD 70 - AC45 - SL33 TNZ

34TH AMERICA'S CUP - 34e COUPE DE L'AMERICA




OUR UPDATED BANNER! 


NOTRE BANNIERE MISE À JOUR !


©François Chevalier 2012



The more the time passes by, the more our banner is longer...
Few more weeks to pass and the first AC72 will be launched!
We will be ready...

Plus le temps passe et plus notre bannière s'allonge...
Encore quelques semaines et le premier AC72 sera mis à l'eau ! 
Nous serons prêts...

©François Chevalier

vendredi 15 juin 2012

VOLVO OCEAN RACE 2011-2012 PENULTIMATE- YACHT DRAWINGS - JUAN KOUYOUMDJIAN WINS ! - FRANK CAMMAS - JUAN K - GROUPAMA - GROUPAMA IV - VOR70

VOLVO OCEAN RACE 2011-2012: GROUPAMA IV WINS THE PENULTIMATE LEG!

By François Chevalier & Jacques Taglang

©François Chevalier 2012

Friday 15th June, 2012

VOR70 Groupama - Juan Kouyoumdjian's design - skippered by Frank Cammas arrived first in Lorient (France) at 13:54 UTC in the penultimate leg. 

In the same time Groupama is presently first overall. 

It is followed by Puma - second Juan Kouyoumdjian's design. 

Third place for Camper - Marcelino Botin's design.

©François Chevalier 2012

Fourth, Telefónica - another Juan Kouyoumdjian's design ! 

Fifth and last: Abu Dhabi - Bruce Farr's design...

©François Chevalier 2012



Huge success for Juan K ! Two designs in the two first! Congratulation !
This success shows how much the probable one design rule for the next Volvo Ocean Race is ridiculous... But wait and see; next episode in July!


mercredi 13 juin 2012

AMERICA'S CUP 1988 - STARS & STRIPES CATAMARAN - FIRST AMERICA'S CUP WINGSAIL - WINGSAIL - USA-1 CATAMARAN


A fault confessed is half redressed…

By ten days we have missed to commemorate the 24th anniversary of Stars & Stripes US-1 Catamaran! 
By Jacques Taglang and François Chevalier

Dennis Conner's 1988 catamaran Stars & Stripes US-1: Launched on May 24th 1988, christened on June 4th 1988 in San Diego... 24 years ago !



©François Chevalier


1988 STARS & STRIPES US-1 CATAMARAN


“The boats to be very big, very radical, and very controversial. The contest will not be a sailboat race. It will be a design lottery in which the sailors will have little or nothing to do with the outcome. In one word, the 1988 America’s Cup challenge will be bizarre.”

That was the assessment of Dennis Conner as published in an interview for the Australian review The Bulletin on December 15th, 1987. The facts would prove Conner right and the unsurprising victory of his small 18.30-metre LOA catamaran, Stars & Stripes, against the huge 27.43-metre LOA monohull New Zealand would remain forever the most incongruous America’s Cup. 



The long silence of the San Diego Yacht Club following Dennis Conner's victory with the 12-metre Stars & Stripes on February 4th, 1987 in Fremantle is often cited as the reason behind the 1988 America’s Cup. Taking literally the words of the Deed of Gift, the New Zealand banker Michael Fay, impatient with American foot-dragging, sent a challenge contrary to all expectations on July 15th, 1987.

His challenger would be a 90-foot monohull, pushing aside the 12-metre class that had been used in each Cup since 1958. Taken aback, the Americans rejected the challenge but Fay asked to the Supreme Court of the State of New York County to intervene. On November 25th, Justice Carmen Beauchamp Ciparick confirmed the validity of the challenge. 




©--


With just 10 months to prepare, the Defender decided upon a radical option. John Marshall, the chief of the Sail America Foundation design team, announced on January 22nd, 1988 that the defender would be a catamaran. The Americans had only eight months left to conceive, build and test a defender capable of repelling the assault of Fay's ‘Big Boat’.

The American decision was simple on one level, yet at the same time was complex. It was obvious that the multihull choice was likely to be interpreted as a provocation and would generate a new legal conflict. But from a sailing point of view it was simple – the Americans didn’t have the time to catch up in conceiving and constructing a big monohull. Instead, it was easier to opt for a catamaran, which was sure to be faster, more elusive, and with a LOA limited to 60 feet (18.29 metres) it would be able to be built quickly. 


©Dan Nerney 1988

On April 15th, 1988 (the immense monohull New Zealand had been sailing in the waters off Auckland since March 27th) John Marshall confirmed that two catamarans were in the process of being built. The first one would be fitted with a soft rig, the second with a hard rig. Conceived in record time, Stars and Stripes, the Defender catamaran was a successful marriage merging cutting-edge naval architecture with aeronautics. For this, Marshall co-ordinated a team comprising exceptional people like Gino Morrelli, who since his youth was fascinated by multihulls. He very quickly became one of the best American specialists and accepted without hesitation the challenge of the America’s Cup. With Bruce Nelson, Britton Chance and Bernard Nivelt, he drew up the catamaran. 

As expected, two 60-foot boats were built, one of them soft-rigged, following Morrelli’s design. The other one was hard-rigged with a winged-mast, a specialty of Dave Hubbard and Duncan MacLane (who had previously worked out this mode of propulsion on 25 feet-catamarans - 7.72 metre) belonging to the C-Class, as the famous Patient Lady. 



To scale up the concept of a mast-wing with articulated flaps from a 25-foot catamaran to a 60-foot machine, Marshall appealed to Burt Rutan's talents, the designer of Voyager, an ultra-light airplane that would make a round the world flight without stopping in 1988. In ten weeks, Rutan, Hubbard and MacLane, supported by a team of 40 people, succeeded in extrapolating the concept. It was an achievement “more difficult than with the airplane wing” Rutan would say later, because of the absolute constraint to save weight. 



©Marshall Harrington
On May 24th, the first boat was launched and in June, Dennis Conner sailed with the hard-rigged cat. The team discovered that in light wind, the traditional soft rigging of the sister ship was more effective. But in more steady, stronger winds, the hard-rigged cat was faster but the risk of material failure was bigger. So Rutan and his team built up a new winged mast and delivered it at the beginning of August. This second structure was 40% bigger and far more solid than the first one. The mast measured 32.61 metres, 5.80 metres more than the first one, and thus the performance was there: the catamaran fitted with the hard rig was preferred to the classic soft-rigged boat. 



©Marshall Harrington


Meanwhile, on May 5th, 1988, as expected, Michael Fay again asked for justice. He argued that the San Diego YC should defend the America’s Cup in September 1988 but with a 90-foot monohull. He noted the Deed of Gift required a match between “like and similar boats.” 



On July 25th, 1988 Justice Ciparick declared Fay’s argument premature and concluded: “The time has come for the sailors to be permitted to participate in the America’s Cup. The parties are directed to proceed with the races and to reserve their protests, if any, until after the completion of the America’s Cup races.” 

©Daniel Forster/Duomo


The "bizarre" 1988 Challenge eventually was sailed on September 7th and 9th off San Diego. It would be useless to hold forth on the ‘mismatch’ on the water. The Stripes & Stripes crew won easily. One matter was certain, this dramatic turn of events put an end to the 12-metre era and opened the way for the present International America’s Cup Class boats. 



The courts would rule again on the 1988 match, firstly on March 28th, 1989 to award the Cup to the New Zealanders and then on appeal to confirm the Stars & Stripes victory. Some months after the race, a Mexican yachtsman, Victor Tapia, acquired the catamaran. Excited by the prospect of watching the 1992 America’s Cup races, Tapia sailed the cat to San Diego. Ten years later, Stars & Stripes was sailing on Valle de Bravo Lake, near Mexico City. The last report we had of it, Stars & Stripes was for sale in Mexico. 



©--
The fate of its sister ship with the conventional soft rig, Stars and Stripes (S1 version) was more spectacular than the 1988 Defender (H3 version). Steve Fossett, the man with dozens of speed records, acquired it in the 1990s.

©Sail America Foundation

Fossett demonstrated that Stars and Stripes still remained among the fastest multihulls of its generation. To this day, it holds, among others, the record for the Mackinac race, sailed on Lake Michigan between Chicago and Mackinac. On the occasion of the 100th Mackinac Race raced on July 18th and 19th, 1998, Stars and Stripes sailed the distance in 18 hours, 50 minutes, and 32 seconds. Since the year 2000, this Stars & Stripes is owned by a yachtsman from Naples, Florida, Mark Reece.



STARS & STRIPES US-1 

Catamaran defender 
1988 

Sail number: US-1 

Code number of the winged catamaran: H3 
USA 



Yacht club: San Diego Yacht Club, San Diego, California, USA 

Successful defender of the 27th 1988 America’s Cup Challenge 

Owner: Sail America Foundation, Inc. President and chief executive officer: Malin Burnham. Stars & Stripes Team, management/administration: Dennis W. Conner 



60 foot wing-sail catamaran 



Design team: John K. Marshall (coordinator), Bruce Nelson, Dave W. Hubbard, Duncan T. MacLane, Gino J. Morelli, Britton Chance, Jr., Bernard Nivelt. 



Wing designers: John Roncz and David Lednicer

Builders 

- Hulls: RD Boatworks, at Capistrano Beach, California 

- Wings: Scaled Composites, Inc., at Mojave, California 



Christened: 4 June 1988 at San Diego 



Year of building: 1988 

Launched: May 1988 

Homeport: San Diego. 



Skipper: Dennis Conner 

Crew: Louis B. Banks, John Barnitt, Carl Buchan, John Grant, Peter Isler, Cam Lewis, Duncan MacLane, Randy Smith, Bill Trenkle, John Wake, Thomas Whidden. 



Data: 



Construction – 



- Hulls: Carbon fiber-Nomex sandwich 

- Masts: Carbon fiber-Nomex sandwich 

- Wing sail: Carbon fiber, covered by Mylar and Dacron 



Dimensions – 


L.O.A.: 18.28 m 

L.W.L.: 16.76 m 

Beam: 9.14 m 

WL beam: 8.90 m
Draft: 3.04 m (with dagger boards down) 

Wing Area: 176.50 m2 (upwind) 

Total sail and wing area downwind: 405 m2 
Displacement: 2.950 tons 

Main wing height (air draft): 32.61 m 



Two wing-sails were built. The biggest one was fitted for racing the Cup. The smallest one had one flap less (air draft: about 27 m).

Observations – 



1988
Two catamarans were built. The first one with a soft sails (conventional), code number S1, the second one with a winged rig. It was this last one that race the 1988 America’s Cup. 



The 1988 America’s Cup races: 7 to 9 September 1988 off San Diego, California. 
Best two out of three races. 


Stars & Stripes raced against the huge 90 feet mono-hull challenger New Zealand KZ-1 

Races: two sailed. 



Race Course: 
Alternate courses 

First race 40 nautical miles long, one windward leg (20 miles) and return. 

Second race 39 nautical miles, triangular course (13 miles by leg, first windward, two and three reaching leg). 



Results: 

Stars & Stripes beat New Zealand KZ-1 by two wins to nil! 



- 7 September 1988, 1st race. Wind speed: 7 to 9 knots. Stars & Stripes beat New Zealand by 18 minutes and 15 sec. 


- 9 September 1988, 2nd race. Wind speed: 6 to 15 knots. Stars & Stripes beat New Zealand by 21 minutes and 10 sec. 




As wrote Tom Coat, the 1988 America’s Cup was “a Cup of controversy”, but it was also, in the spirit of the tradition of this event, a fantastic technical challenge on both sides. 



1989
Stars & Stripes was sold and moved to Mexico. Victor Tapia owned it. 



1992
Victor Tapia took Stars & Stripes to San Diego for the 1992 America’s Cup Challenge, and used it as a charter boat. He also raced the boat in California during that time. 



2002Stars & Stripes was an attraction for a deluxe hotel in Mexico, the Menson del Viento. Its homeport is Valle de Bravo, Mexico. 



2005 
Still in Mexico, Stars & Stripes appears to be for sale…


On August 2009, Stars & Stripes was still at anchor in Mexico…

©François Chevalier 2012




lundi 11 juin 2012

AMERICA'S CUP - 34TH AMERICA'S CUP - SAN FRANCISCO - CATAMARAN - HISTORY - DUSTER

WHAT A PREMONITION!


One year after the launching of his catamaran Amaryllis (1876) - the first modern cat ever designed and built - Nathanael Greene Herreshoff designed John Gilpin (1877)...


©François Chevalier

©François Chevalier




In the same time, this little racing catamaran, Duster (1877), sailed by one person was cruising right past front of the San Francisco Yacht Club's club house. 


©University of California - Berkeley/Bancroft Library




135 years before the AC72 of the 2013 America's Cup first sails on the same stretch of water!

By Jacques Taglang

AMERICA'S CUP - HISTORY OF YACHT DESIGNS - TWIN-KEEL - YACHT DESIGN INNOVATION - FIN-KEEL - BALLAST

THE TWIN-KEEL, A HUNDRED YEAR-OLD DREAM

By Jacques Taglang & François Chevalier


In 1891 Dilemma was launched, the first true modern fin keel deserving of this name and with it, Nathanael Greene Herreshoff revolutionised the science of naval architecture. 
©François Chevalier 2012


By demonstrating the design could sail effectively, he freed the creative spirit of numerous designers and within a year his ‘invention’ had spread around the world.

©François Chevalier 2012



Dilemma also generated some audacious interpretations, which at the time appeared to be dead ends, including the twin-keel (fork or tandem keel). Who could have known that a century later, these very designs would be hidden under the skirts of several America’s Cup Class boats? 

1893: A first attempt at the ‘twin-keel’

Dilemma (1891) was one of the American designer Nathanael Greene Herreshoff’s most brilliant designs, and this is from a man who would model no less than six successful America’s Cup defenders. Dilemma sailed around the world and inspired some audacious copies including the enormous 1893 America’s Cup defender candidates, the 25.90 meter Jubilee and Pilgrim.



Jubilee - Sail Plan - ©François Chevalier








Pilgrim - Sail Plan 1893 - ©François Chevalier



However some particularly imaginative spirits also thought about further developing the fin keel. The English naval architect Linton Chorley Hope (1863-1920) proposed a curious system intended for a small sailboat which would allow for the lead bulb to be raised through two articulated metal fins. This system would allow the sailors to adjust the height of the ballast according to the wind. 

Jacques Taglang's Collection - The Yachtsman 1893


Linton Hope suggested even reducing or increasing the width of the fins, but at the time, fluid dynamics was in its infancy, and testing would have to wait. But by 1901 the Scottish naval architect George Lennox Watson would lead the pack when he made the first ‘towing tank’ tests with Sir Thomas Lipton’s America’s Cup challenger, Shamrock II and trialed his models with various heeling and course angles. 

1895: A surprising ‘trim tab’ twin-keel …

Three years after Dilemma, a surprising drawing was published in The Yachtsman magazine, showing a double keel formed by two fixed metal fins ballasted by a lead bulb. A sort of rudder (the ancestor of the trim tab?) was fitted between both fins of the keel. This surprising system was tested on a small dinghy.

Jacques Taglang's Collection - The Yachtsman 1895


The conclusion was interesting: “The boat’s worst point of sailing was her windward work, and she was much improved in this respect“ by the use of this ‘twin-keel’ with adjustable flaps. The boat, also fitted with an aft rudder, pointed very close to the wind and the stronger the wind, the better it performed, according to the authors of the comment that explained the drawings. 





1898: A frightening boat… 

Two years later, another drawing was published that elicited fear from observers. The drawing concerned a Sharpie type craft of 13 meter LOA, drawn by Captain Marony. Unfortunately, it would never be built. But most people conclude that this plan is the first twin-keel deserving of the name. Commentators at the time however, were not very enthusiastic.

Jacques Taglang's Collection - The Yachtsman 1898

"We do not mean to commit ourselves by offering any opinion as to her merits, but we would most decidedly hesitate to make a voyage in her from the Solent to the Clyde. We are afraid the crew would require more than the usual emolument if they were required to live on board. It would be very interesting to see such a craft competing with the present types, but, though the cost of construction would be small, we are afraid our wish will not be granted.” 

1992: The Little Red Skiff!

The America’s Cup, as history shows, is a laboratory for many things, and especially, yacht design and naval architecture. It is true that in the case of appendages (the keel, rudder, trim-tab) any changes have been long in coming. A glance at the record shows some remarkable developments, such as those of Jubilee and Pilgrim in 1893, of Intrepid in 1967, Olin J. Stephen’s drawing who created the trim tab and fitted a suspended and separate rudder, and of Australia II in 1983 with which Ben Lexcen dared to build the famous ‘inverted’ and winged keel. More recently there has been US 61 the Gary Mull design that had this twelve meter boat with two rudders, one being fitted just aft of the bow. Tom Blackaller would sail this boat into the semi finals of the 1987 Louis Vuitton Cup in Fremantle. This configuration would be seen again five years later on Nippon JPN-26, skippered by Chris Dickson.

Then, in 1992, with the advent of the America’s Cup Class, imaginations were set free and in San Diego, no less than four competitors were fitted with a tandem or twin-keel with double rudders. The defence candidate Stars and Stripes USA-11 skippered by Dennis Conner, sailed with this before quickly switching to more classical configuration. 

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One of Japanese challengers, Nippon was also fitted with a twin-keel while Iain Murray’s Spirit of Australia AUS-21 raced during the Louis Vuitton Cup Round Robins with a tandem keel. But the most surprising 1992 America’s Cup Class boat in San Diego was New Zealand NZL-20. Nicknamed the Little Red Skiff, NZL-20 was a Bruce Farr design. 


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It was drawn up from the very beginning with a twin keel and was fitted with a small bowsprit. It was this small spar that would apparently cause the defeat of the Kiwis, following a protest by the Italians of Il Moro di Venezia ITA-25. On the verge of winning the Louis Vuitton Cup, the New Zealand team was seriously destabilised by the protest, and the Italians advanced to the America’s Cup. But that doesn’t detract from the speed and efficiency demonstrated by the Kiwi boat with its ‘twin-keel’.










Fatal attraction



Despite the eventual failure of the Kiwis in 1992, in 1995, it seems that the Australians led by John Bertrand tried a similar appendages configuration on oneAustralia AUS-29 or AUS-31. But a structural weakness would prove fatal for AUS-31, which broke up and sank in testing conditions. During the millennium America’s Cup in 2000, only the Swiss boat behAPpy SUI-59 used the curious appendages designed by Peter Van Oosanen, but it proved to be a very difficult boat to sail with an aft rudder ballasted with a lead bulb doubled by a fore-ballasted rudder or canard. Despite its difficulties, the boat showed remarkable speed on occasion. Then, in 2003, the British challenger candidates Wight Lightning GBR-70 and White Magic GBR-78 (Rob Humphrey, Stephen Jones, Tim Corben, Akihiro Kanai and Taro Takabashi designs) also tried the twin keel for a time, but it didn’t prove to be the magic bullet the team was hoping for and the GBR Challenge was eliminated in the quarterfinals of the Louis Vuitton Cup.