In build at CDK
 

In build at CDK

New Groupama unveiled

Despite winning most of the events this year, Franck Cammas has an even faster boat nearing completion

Friday November 14th 2003, Author: James Boyd, Location: France
Franck Cammas may be leading the Transat Jacques Vabre's 60ft trimaran division at present, but this isn't preventing the amazing 30 year old from having a replacement for his current steed built.

Cammas is one of the most exceptional individuals in yacht racing. Winning the prestigeous Solitaire du Figaro at the tender of age of 24 was his ticket through to the 60ft trimaran circuit. The year after his Figaro win with the help of his insurance company sponsor Groupama he cobbled together a new van Peteghem-Prevost design using other project's moulds. It took two years before his first significant win - the ultra-quick fully crewed Quebec to St Malo in which the weather conditions were such that several of the 60ft tris broke the 600 miles in 24 hours barrier.

He won the Transat Jacques Vabre in 2001 and since the departure of Loick Peyron (another child prodigy in the multihull class) has been the dominant force on this highly competitive circuit. Over six seasons he has scored 25 podium positions and nines victories in 29 races, winning the ORMA annual circuit in 2000 and 2001. This year he was won all the events in the ORMA circuit, both inshore and offshore, with the exception of the Cagliari Grand Prix where Groupama finished second to Sergio Tacchini.

"When Groupama gave us the green light to build a new trimaran in 1997, we had almost zero experience and a limited budget to make studies," says Cammas. "Therefore we built a boat that was simple to develop and reliable."

Like most of the 60ft trimarans, Groupama 1 evolved over her career with intensive work in the boatyard, changing masts, floats, foils, appendages, etc. Currently all that remains of the original boat is her main hull and beams.

"Thanks to the constant support of Groupama, we evolved the boat over the years to keep it competitive. If, today we are still in front of the competition it is thanks to our crew," continues Cammas. "Our objective is to remain in this circuit because the boats and the program of races represent, I believe, the highest sporting and technological challenges in yacht racing".



For Groupama 2 Cammas has returned to Marc van Peteghem and Vincent Lauriot Prevost. Compared to other trimaran campaigns the build-up for the new Groupama has been lengthy. Design work began in June 2002 and the new boat is not due for launch until May 2004. "There has been no hurry because we are on the pace with the current Groupama," says Cammas. "Therefore we started with a blank sheet of paper, like Fujifilm - to design an ideal boat in our eyes without constraints and to give us an opportunity to look at all the elements constituting a multihull."

In addition to van Peteghem/Prevost Cammas also wanted to include some new blood in the design process and for this reason brought in his friend, German A-class catamaran designer Martin Fischer. Fischer had input into the hull design and also the appendages. In addition the design team included aerodynamicists Yann Roux and Mick Kermarec and structural engineers Herve Devaux and Franck de Rivoyre, with the boat project managed by Stéphane Guilbaud.

Impressively seven yards have been used in the construction of the new boat: CDK (main hull), Décision S.A. (beams), Gépéto (floats), AMCO, Lorima (mast), Profil Composites and Charlie Capelle. The boat is at present being assembled at CDK in Port la Foret and it will be fully finished off back at the Groupama base by the old submarine silos in Lorient.

So what is different about the new boat? Firstly she is entirely new - she has come out of a completely new set of moulds, something of a rarity in the trimaran fleet.

For the rig they have studied the sail plan in an attempt to increase efficiency (fore and aft dimensions and mast height are limited in the ORMA class) particularly in terms of the aspect ratio and the amount of jib overlap. "In fact we didn’t work on the biggest sail possible," says Vincent Lauriot Prevost. "We tried to work more on the efficiency due to the geometry of the sail plan." Compared to the old boat the rig is further aft, with a shorter boom and the forestay has moved aft too, but this configuration allows for larger gennikers and spinnakers.

Compared to the old Groupama the new boat will have an X-beam configuration like the new generation of VPLP designs. "We try to work on the fact that when the crew is working in the central cockpit it doesn’t affect the longitudinal trim of the boat."
The weight of 12 crew, as will be used for the grand prix, on a 6 tonne boat is significant and on the boats where the cockpit is a long way aft this moves the centre of gravity of the boat aft signficantly. "So all the winches are more forwards than before, close to the centre of gravity," says Lauriot Prevost. The winch positioning is similar to Michel Desjoyeaux's Geant, but because the new Groupama's rig and thus her centre of gravity is further aft, so the CoG will be closer to the crew.

The design team also studied the optimum beam length, and positioning. Her overall beam of 18m is the same as Geant, but 30cm more than her predecessor and slightly narrower than boats like Thomas Coville's Sodebo.

The design team had tank testing to study the drag of different hull shapes carried out at near Rouen at the facility of DDA, who have previous worked on France's America's Cup challengers.



"For the floats we made three models," says Lauriot Prevost. "One model we took as the base were Groupama 1's floats. Another was an evolution of the Belgacom shape and the third came from Martin Fischer. His idea was to develop forms which are inspired from the Hobie Fox with the reverse bow and a round section on the bottom for all the length of the hull with an inverse V-shape on the deck.

"The idea is to be able to work on a kind of planing hull with a very fine angle of entry when you have 3-4 tonnes displacement or more and very low wetted surface area because of the round bottom. So we tested the three hull forms and it appears that the two new forms were better than Groupama 1 - thankfully! The Martin Fischer form on flat water gave the best rests in terms of drag, but we had problems with this form for two reasons: one was that it generates a lot of slamming which gives a brutal movement to the boat, and secondly we felt it didn’t have enough reserve of buoyancy if the boat digged the bow into the water. But the concept interested us so we adapted Martin Fischer’s proposition for offshore racing."

The result is that the new Groupama's floats will have a finer angle of entry, a higher prismatic co-efficient with a planing bottom on the aft sections.

Obviously the role of the curved foils that have developed over the last four years since Marc Lombard first introduced them on the 2000 version of Banque Populaire, play a significant role on how the floats behave. "We consider the foils quite a lot because it looks like we have good reliability with the foils now," says Prevost. "That means we can be a bit more extreme in the forward form, because they provide dynamic lift at high speed."

Because of the effect of the foils, surely the design of the float should start relying more on the foil to allow volume (and weight) to be removed from the float. Prevost thinks not and says they have taken a more conservative approach. "We still want to have volume in the bow - that was one of our questions with Martin Fischer’s form. So we are still conservative. We didn’t make small volume floats. We have kept the same amount of reserve buoyancy but we have redistributed the volume vertically."

Incredibly the present curved foils are so effective that on a reach in flat water there are occasions when they are almost the only part of the boat in the water. In fact because there is only one lifting foil in each float the boats have a tendency to lift their bows out and drag their transoms. The floats on the new Groupama take this into account and their aft sections should not provide too much drag when the boat is riding on its leeward foil.



In the centre hull the new Groupama has a daggerboard with a trim tab. In order to keep it simple and reasonably light weight the daggerboard only goes up and down and doesn't work like a centreboard as it does on some of the other boats. "Franck now has a good idea of how the boat has to be balanced and so we tried to reduce weight and complexity by having a fixed angle for the daggerboard," says Lauriot Prevost, who adds that the section is new and optimised to work with the trim tab, which accounts for a hefty 28% of the foil's area.

At present their first set of rudders have been designed for offshore races. There will be a lifting transom-hung rudder for the main hull while the rudders in the floats will have a greater surface area than the ones currently on Groupama 1.

From the photographs the main hull appears to be very slab-sided. "Franck didn’t want any flare," says Lauriot Prevost. "The other parameter we tried to take into account was the wetted surface area for the mainhull and we tried to have a good compromise with these parameters, taking into account that the main hull is usually used for big buoyancy at low speeds, medium buoyancy at high speeds and downwind with breeze offshore."

Following on from last year's disastrous Route du Rhum the structure on a majority of the 60ft trimarans has been modified, but with the new boat these changes have been incorporated from the outset. "We are using a different density sandwich core in the construction," says Lauriot Prevost. "We have some different features to try to make it better for impact. We have had added some bulkheads on the existing boat and on the new boat there are some parts of the boat where we have added some bulkheads, but for different reasons. In the main hull, for example, there are more straight panels than before."

Over the last few years increasingly complex appendages and canting rigs have increased the weight of the boats. The new Groupama is expected to weigh in at around 5.8-6 tonnes. Thus to reduce weight the builders are spending considerable time on the moulds to reduce the amount of fairing necesary to an absolute minimum.

"In terms of complication we have simplified the centreboard box and we are not at the maximum lateral rake of the mast so we can reduce the weight of the hydraulic rams," says Prevost. "We have quite a simple rudder system, so I would say the only complication compared to the original boat is the fact we can adjust the rake of the mast by 3-4 degrees."

In terms of canting the rig from side to side they are limited to around 8-9 degrees compared to 10-12 degrees on some of the other boats. "Franck thinks it is not necessary to have such a big angles versus the weight you need for bigger rams more hydraulics, etc," says Lauriot Prevost. Like Geant and Fuji the hydraulic rams at the ends of the her shrouds will be located on the back of the aft beam.

The price tag of the new Groupama is around 3-3.2 million Euros - so expense compared to the rest of the fleet. However one of the advantages of building a whole set of new moulds is that they can be rented out and some of this cost can be recouped. For example the Belgacom team built new float moulds for example and then rented them out to four different teams.

A new tri built from existing moulds Prevost estimates costs around 2 million Euros. Much of the cost of building a 60ft trimaran goes into the numerous tweaky appendages - building three rudders which lift and curved foils for the floats that won't break when the entire boat is resting on it, and not to mention a 5m long daggerboard with a large trim tab, is an expensive business.

Clearly Groupama 1 is no slouch. So it will be quite important to ensure that the new boat is faster than the old one... Until such time as it is it is unlikely that Cammas will allow the new boat to go racing. "The VPPs shows her to be faster in most conditions," says Prevost. "On hull drag the new boat is better and the centring of its weight is better and the construction is better and the appendages are better and the sail plan efficiency better too. We’ll see..."

Cammas expects to race Groupama 1 - known as a good upwind boat - in next year's Transat and much two boat testing is expected in order to get the new boat up to speed quickly - new trimarans seem to take around two years before they finally become competitive. Groupama 2 is expected to make her debut in next year's Quebec-St Malo race.

See page 2 for some CAD images of the new hull
On page 3 there is a lines plan of Groupama 2
On page 4 see the comparison of the lines of both the GroupamasFranck Cammas shows off his new boat

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