mercredi 6 novembre 2013



written by Francois Chevalier 
translation by Donan Raven - see

As soon as she hit the water, Magic Carpet 3 took a flying start. Her designer delivered a real winner thanks to her very special lines. Whether in light airs or in a sustained breeze, she has outclassed her competitors. 

 Francois Chevalier ©2013. Magic Carpet 3 Sail Plan, Reichel/Pugh design
Reichel/Pugh had exhaustively developed the narrow yacht with Wild Oats XI, which, throughout her career thus far, has received all possible appendages, including a canard in her original CBTF configuration.

 Francois Chevalier ©2013. Magic Carpet 3 Lines, Reichel/Pugh design

By raising the "progressive" hard chine, the designers of Magic Carpet 3 have significantly reduced the waterline beam when the yacht is level, thus keeping the wetted surface to a minimum. As the Wally class rule forbids canting keels, Reichel/Pugh opted for a relatively large displacement, with a large quantity of the overall weight placed in the finkeel ballast. When the yacht is heeling, the hull sails on a flat surface as well as the hard chine (which provides lateral resistance) and starts to plane at the slightest of breezes. The same hull shapes can also be found on the latest generation of the Open 40 class yachts, which have proved to be more complex to optimize than their predecessors. 

 Francois Chevalier © 2009/2012. Wild Oats XI lines,  Reichel/Pugh design

Wild Oats XI is a much narrower yacht than Magic Carpet 3 with a waterline beam of just 4.10m. Her lines features a slightly rounded bilge, flaring topsides, and a moulded depth positioned forward of the keel fin. When heeling, the waterline is as long as the full length of the yacht, the wetted surface is reduced, but the flaring topsides do not provide lateral resistance like more recent yachts with chine-bilged hulls like Magic Carpet 3 or Rambler 100 (Juan Kouyoumdjian design, formerly Speedboat). 

Francois Chevalier ©2011. Rambler 100 lines, formerly Speedboat, now Loyal 100, Juan Kouyoumdjian design

The shape of Rambler 100 (formerly Speedboat, now Loyal 100) for is similar to that of a motor boat. Her hull lines are very sleek and it is difficult to read the shape of her aftersections. Because of this, her horizontal sections (which are parallel to the waterline) all stop abruptly at the transom. Generally, the beamier the vessel, the larger the developed surface of the hull and deck, incuring extra weight to the yacht. But the closer the overhead shape of the deck is to a triangle, the lesser this developed surface actually affects the hull weight and Rambler 100 is very close to a triangle. Half the yacht's weight is located in the canting keel, which is swung to windward. When the wind strengthens, 8 cubic meters of water are pumped to the windward liquid ballast tank, which provides Rambler 100 with a huge righting moment. 

Francois Chevalier ©2012. Maxi Scow lines - François Chevalier's design 

Francois Chevalier ©2012. - Maxi Scow sail plan, Francois Chevalier's design

My 100ft Maxi Scow proposal features hull lines which are close to those of a surf board. This increases the drag in the light airs compared with a narrow yacht like Wild Oats XI, but gives her greater ability to plane in the puffs. When heeling, the wetted surface is reduced and the angle between the heading and the centerline of the yacht is smaller than on any other maxi-yacht. Furthermore, her shape stability is also greater. 

Francois Chevalier ©2012. WallyCento FcH lines, Francois Chevalier' design

Francois Chevalier ©2012. Maxi Scow sail plan - François Chevalier's design

A stand off between these five Maxi yachts in a New-York Bermuda, a Fastnet or Sydney-Hobart would be an educative and unforgettable spectacle. 


Magic Carpet 3 / WallyCento 

Designer: Reichel/Pugh 
Builder: Wally, Ancona (ITA) 
Build material : Carbone 
Complies with the WallyCento class rule 
Length of Hull: 30.48m (100ft) 
Load Waterline Length: 29.49m 
Beam: 7.19m 
Waterline beam:4.70m 
Draught: 6.20m / 4.50m 
Displacement: 50 tonnes 
Lifting keel 
Air draught: 45.00m 

Wild Oats XI 
Maxi sloop 
Designer: Reichel/Pugh 
Builder: McConaghy's, Sydney (AUS) 
Date of launch: December 2nd, 2005 
Length of Hull: 30.48m (100ft) 
Length Overall: 33.83m 
Load Waterline Length: 29.70m 
Beam: 5.40m 
Waterline beam: 4.10m 
Mast length: 44.10m 
Draught: 5.50m 
Weight: 32 tonnes 
Ballast: 14 tonnes 
Sail area, mainsail: 382m² 
Sail area, jib: 228m² 
Sail area, genoa: 505m² 
Sail area, spinnaker: 880m² 

Rambler 100 (now Loyal 100, formerly Speedboat

Designer: Juan Kouyoumdjian 

Builder: Cookson Boats, Auckland (NZ) 
Date of launch: April 17th, 2008
Length of Hull: 29.99m 
Load Waterline Length: 29.99m
Beam: 7.00m 
Waterline beam: 4.95m 
Draught: 5.70m
Air draught: 46.50m
Bowsprit: 3.60m 
Displacement: 30.6 tonnes
Ballast: 15 tonnes
Liquid ballast tanks: 8,000 litres 
Sail area, upwind: 630m² 
Sail area, downwind: 1,340m² 

MaxiScow 100 proposal 

Designer: Francois Chevalier YD 
Proposed builder: either Multiplast (France), Green Marine (UK) or Cookson Boats (NZ) 
Length of Hull: 30.48m (100ft) 
Load Waterline Length: 26.70m 
Beam: 7.20m 
Waterline beam: 5.40m 
Draught: 5.60m 
Displacement: 38 tonnes 
Canting keel 
Air draught: 46.00m 
Sail area, mainsail + jib: 628m² 
Sail area, mainsail + gennaker: 1,110m²

WallyCento (Projet)

Designer: Francois Chevalier YD
Proposed builder: either Multiplast (France), Green Marine (UK) or Cookson Boats (NZ)
Length of Hull: 30.48m (100ft)
Load Waterline Length: 26.70m
Beam: 7.20m
Displacement: 45 tonnes
Lifted keel
Air draught: 45m
Sail area, mainsail + jib: 592m² 
Sail area, mainsail + gennaker: 1,000m² 

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