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Photoboy
12-21-2014, 06:32 PM
Peter Gustafsson (http://www.blur.se/2014/12/19/tt-scow-fran-thomas-tison/) penned this article on the new TT Scow.



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TT Scow by Thomas Tison

It's fun with new design ideas. Foiling have well been the hottest in recent years, but also scow concept shows up more often. Who does not remember David Raisons nosed mini that won Transat this year.Thomas Tison has worked with Mascalzone Latino, Team Origin and is now at Artemis design department at San Francisco (living with Fredrik Loof). Now he lies behind a super easy one-person dinghy with ostagad mast which can be tilted 15 degrees to windward. The question is whether it is too high tech in a traditional world, or whether this segment now belongs Moth dinghies?


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Thomas Tison and Nomad Composites (Benoit QUEMENER) are to launch an extreme and innovative single-handed dinghy this winter.

The TT Scow has been designed with only speed in mind. It is the only recent changes dinghy to have an unstayed canting wing mast for Improved aerodynamic efficiency. It is overpriced, has a scow hull shape for improved shape stability. Built to a high standard in carbon fiber, it is the ideal dinghy for adults, especially those who like to sail solid, with minimum constraints and on a nicely finished and exclusive boat.

The prototype has been built and will be undergoing testing this winter in France. It will then be on display in Europe and in the USA.

The main features are:

- High stability
The scow hull size and the hiking wings make the boat as stable as a skiff. It can Therefore carry a large and well proportioned sail plan without trapeze.

- Efficient

The unstayed, canting and rotating wing mast ensures the flow on the mainsail is clean and That the mainsail is well in the wind, at any heel angle. The hull shape helps initiate planning early and The long bow overhang increases waterline length upwind.

- A stiff, rugged and lightweight structure

No E glass ice distressed in the construction. The boat is built using carbon sandwich laminates only. The foam core and the outer skins are designed for robustness where it matters, while keeping the overall displacement really low for a boat this size.

- A unique style, Carefully built and engineered

The boat was engineered in Germany, and care fully built in France by Benoit Quemner (Nomad Composites) Who has, amongst other things, taken part in the construction of Sail Rocket. Thomas Tison is a Naval Architect Currently working for the America's Cup.



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Thomas've made some scow-designs before, without their being realized. Among other things, this 14.2-meter racer. Even Reichel / Pugh had a maxi on the drawing board for a couple of years ago.

Below, he tries to sort out the benefits.



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The main benefit of scow hulls ice shape stability which is a cubic function of hull beam. Hull beam in this case is taken as the average hull beam Ie a barb will be beamier from a shape stability point of view If it has a constant maximum beam compared to the more triangular shapes induced by the standard vertical bows. More shape stability allows to carry more sail area, and there fore create more drive force, for the same weight (improved power to weight ratio). Typically a scow hull shape, for the same hull length and maximum hull beam as a standard hull shape Will create 30% more righting moment.

The other positive point Is that the tendency of hulls to pitch by the bow (bow down) the reduced ice much. This bow down attitude is due, on the standard hull shapes, to the volume above the waterline, by the transom, which goes under water when the boat heels. This effect is what drives the transom shapes of TP52s and Mini Maxi currently. Scow hull shapes however, being equally wide all along, I do not have more volume in the back When the boat heels and it is Therefore possible to push the boat harder in some cases overpriced Reduce sailing displacement as some classes use water ballast for this purpose .

Another key point Is that using the bow overhang and the capacity of scow hull shapes to behave well heeled when allows to design two specified hull shapes. On one side, an upwind hull shape (large heel angles) With the increased waterline length provided by the bow overhang, with rounded sections for minimum wetted surface area. And on the other side, a reaching hull shape, with flatter sections to create lift at lower heel angles.

One thing which is clear from the lines above Is that scow hull shapes musts heel, and using a canting mast therefore makes a lot of sense.

(I wrote an article about scows Seahorse some years ago (published in June 2011) Which Could be a good reference)

Peter Gustafsson

http://www.blur.se/2014/12/19/tt-scow-fran-thomas-tison/

Prince of Whales
12-22-2014, 11:46 AM
46' is a lot of scow.

How can they carry enough beer to keep the crew lubricated all the way to Stockton?