The Dufour 40 Sailboat
Specs & Key Performance Indicators
The Dufour 40, a light displacement fractional sloop, was designed by Umberto Felci and built in France by Dufour Yachts.
The Dufour 40
Published Specification for the Dufour 40
Underwater Profile: Bulb fin keel & spade rudder
Hull Material: GRP (Fibreglass)
Length Overall: 40'5" (12.3m)
Waterline Length: 35'3" (10.7m)
Beam: 12'10" (3.9m)
Draft: 5'5" (1.7m)
Rig Type: Fractional sloop
Displacement: 17,196lb (7,800kg)
Designer: Umberto Felci
Builder: Dufour Yachts (France)
Year First Built: 2005
Published Design Ratios for the Dufour 40
1. Sail Area/Displacement Ratio: 20.9
- Less than 16 would be considered under-powered;
- 16 to 20 would indicate reasonably good performance;
- Over 20 suggests relatively high performance.
2. Ballast/Displacement Ratio: 36.1
- Under 40: less stiff, less powerful
- Over 40: stiffer, more powerful
3. Displacement/Length Ratio: 175
- Under 100: Ultralight
- 100 to 200: Light
- 200 to 275: Moderate
- 275 to 350: Heavy
- Over 350: Ultraheavy
4. Comfort Ratio: 24.2
- Under 20 indicates a lightweight racing boat
- 20 to 30 indicates a coastal cruiser
- 30 to 40 indicates a moderate offshore cruising boat
- 40 to 50 indicates a heavy offshore boat
- Over 50 indicates an extremely heavy offshore boat
5. Capsize Screening Formula: 2.0
- Under 2.0 (the lower the better): Better suited for ocean passages
- Over 2.0: Less suited for ocean passages
read more about these Key Performance Indicators...
Summary Analysis of the Design Ratios for the Dufour 40
1. A Sail Area/Displacement Ratio of 20.9 suggests that, in the right hands, the Dufour 40 will have enough performance to leave most other sailboats of similar waterline length well astern.
2. A Ballast/Displacement Ratio of 36.1 would usually mean that the Dufour 40 would have a tendency to heel uncomfortably in a gust, and need to be reefed early to keep her sailing upright in a moderate breeze.
However, as she has much of her ballast concentrated in a bulb at the foot of her keel, she's likely to be considerably stiffer than her published Ballast/Displacement Ratio might suggest.
3. A Displacement/Length Ratio of 175, tells us the Dufour 40 is a light displacement sailboat. If she's loaded with too much heavy cruising gear her performance will suffer to a degree.
4. Ted Brewer's Comfort Ratio of 24.2 suggests that crew comfort of a Dufour 40 in a seaway is similar to what you would associate with the motion of a coastal cruiser with moderate stability, which is not encouraging news for anyone prone to seasickness.
5. The Capsize Screening Formula of 2.0 tells us that a Dufour 40 would not be as good a choice of sailboat for ocean passage-making, owing to the increased risk of capsize in strong winds and heavy seas when compared to a sailboat with a CSF of less than 2.0.
May 16, 22 04:32 AM
Interested in the Etap 32i sailboat? Here are the pics, specs and performance predictions you're looking for...
May 15, 22 10:55 AM
Interested in the X-332 sailboat? Here are the pics, specs and performance predictions you're looking for...
May 14, 22 06:47 AM
Interested in the Jeanneau Sun Odyssey 44 sailboat? Here are the pics, specs and performance predictions you're looking for...