Open Division
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The 'A' Class catamaran is bound by a box-rule, which has allowed the development of platforms into full-foiling mode.
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Video: One of the first established foilers at Takapuna explained
Video: Dave shoes us how to foil downwind in a modern foiler
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The foiling revolution in the A Class began right here in New Zealand with the 2014 Takapuna Worlds. Inspired by the developments of the America's Cup AC72s in San Francisco, some of the greatest sailing minds came to the A Class to develop an understanding of the potential of new foiling technology.
Early 'J' shaped dagger boards saw two hulls leave the water for the first time (if sailed in a fine balance!). Since then, the 'Z' shapes have proven most successful, with stock boards developed by eXploder in Poland seeing wide use in the class. Rudders have seen massive development, not only to allow complex pitch trim of the rudder winglets, but also to withstand the much higher loads of foiling. |
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You can expect to find these controls on modern foiling A Class catamarans:
Main foil pitch
The angle of attack of the dagger boards are adjusted by sliding the top bearing by either using pulleys or belt-driven gearing.
Rudder Global Pitch
The net lift from the rear foils need to be adjusted together between upwind & downwind sailing. Often the rudder stocks are driven by a push/pull spring system, using pulleys and cleats to allow control form the trapeze.
Rudder Differential Pitch
In order to harness all the power of the A Class upwind, rudder winglet pitch can be differentiated by sliding a length of the rudder global control between both hulls to offset the rudderstocks.
Mast Rotation
For upwind foiling, sails are getting flatter and the masts are often de-rotated to the centre-line to create more sail twist.
+ Traveller, cunningham and any other rope you need to go fast!
Main foil pitch
The angle of attack of the dagger boards are adjusted by sliding the top bearing by either using pulleys or belt-driven gearing.
Rudder Global Pitch
The net lift from the rear foils need to be adjusted together between upwind & downwind sailing. Often the rudder stocks are driven by a push/pull spring system, using pulleys and cleats to allow control form the trapeze.
Rudder Differential Pitch
In order to harness all the power of the A Class upwind, rudder winglet pitch can be differentiated by sliding a length of the rudder global control between both hulls to offset the rudderstocks.
Mast Rotation
For upwind foiling, sails are getting flatter and the masts are often de-rotated to the centre-line to create more sail twist.
+ Traveller, cunningham and any other rope you need to go fast!
In New Zealand, most foilers are converted pre-2014 hulls. This dramatically reduces the cost of getting into foiling, and unlike other foiling classes such as Moths, 'classic' hulls have remained reasonably competitive by chopping and changing appendages to stay modern.
The NZ association have a huge amount of know-how when it comes to converting into foiling so please get in touch if you are interested.
The NZ association have a huge amount of know-how when it comes to converting into foiling so please get in touch if you are interested.
Much of open division development is now focused on improving upwind foiling VMG. This is a fine balance, as optimizing for this performance bracket often damages performance in other areas. Indeed in sub-6kt conditions, classics have an established advantage over foilers on the racecourse.
If we had a crystal ball, you'd expect to see some of these developments going forward: Optimization of all wings; sails, winglets, foils. The way these systems are actuated will change to be easier to access and control from the wire. Foiling platforms might also be built down to the class weight with optimized laminates.
If we had a crystal ball, you'd expect to see some of these developments going forward: Optimization of all wings; sails, winglets, foils. The way these systems are actuated will change to be easier to access and control from the wire. Foiling platforms might also be built down to the class weight with optimized laminates.
