Apr 20, 2016

New 'Z' board Cruiser-Racer Cat: The North Wind 55

Just like the guys at Morrelli & Melvin , Gonzalo Redondo continues to work with the whole range of Multis. Lastest work for Gonzalo / D3 Applied Technologies has been the new foils & hulls for Exploder , now he has applied the A-Cat 'Z' foil tech to a 55' Cruiser-Racer from North Wind. Below a Q&A we did with him this week to know more about the implementation of the Z system on the North Wind 55. Below also official press realease , more info at northwindyachts.com
- CSN: You were called to be part of this new NW project, which was the main goal 55 , it seems this new cat targets an upgrade from MM Gunboat series
for cruising and racing, I mean which were the design requirements you were requested to apply? 

Gonzalo Redondo: The owner of North Wind Yachts, Enrique Ribot, called us for this project as he wanted a unique high performance catamaran. He had a great vision and put together a team composed of Francois Perus & Romain Scolari as naval architects, Jonas Hertwig responsible for interior and styling and Isonaval looking after systems and overall project? supervision. At D3 Applied Technologies we are responsible for performance, mainly hull and appendage design.

The NW55 has been developed as a high performance cruising catamaran which competitive owners could bring to regattas and be substantially faster than similar sized vessels.

- Which is the purpose of fitting this rather large Cruising cat with Z style boards and T rudders as seen in the render? Full flight or reducing wet surface skimming? 
GR: Funnily enough we faced the "remove appendages from the top" restriction, which is why I thought of Z-boards straight away. There will be two versions, one with standard C-boards and one with Z-boards as you see in the render. We are still developing the high performance package. I expect low-riding and skimming.

- Which a re the benefits of Z over curved then if full flight is not targeted a priori?

GR: Well, when it comes to the shape of the board, at the end Z boards are similar to the S boards used a few years ago. One nice benefit of Z boards is that you can unload the tips at the bottom. Also the exit from the hull is better, as you can make it 90 degrees.

Also, since the horizontal plane is more angled than C-boards you have the possibility to use the windward board to either create lift or increase righting moment as required. Since the windward board can be used to increase performance you do not pull it up, meaning the catamaran could be sailed short-handed as one could forget about the up-down system.

The main advantage of these Z foils is that in case of flying/jumping they have better heave stability than C foils. The biggest difference is dynamic stability and control... Some static VPPs might tell you that a C board with winglets are better.

- We've seen how winglets reduced pitching even in the A-Class flaoting mode, so besides the skimming we can say winglets are also a safe asset for the 55?GR: Totally, they will be offered as standard in both configurations. Cruising and comfort go together, as do racing and control, so there is no reason not to include them. However, and this is something we are investigating in the A-Class, the foil sections at the winglets we are using are no longer symmetrical. Flight dynamics are very interesting in this respect. The A-Class winglets are now asymmetrical so there is a bit of a tandem wing configuration on them. On the other hand, the kitefoil elevators we are designing are also asymmetrical but in this case the section is upside down, creating a bow up attitude which is what riders can control.

- We've seen the smaller & lighter 40' G4 foiling good with TNZ 3pt foil system, can we expect the A-Cat type 4pt you guys are using in this NW 55 , to be efficient for full flights on a similar platform like the G4? Does NW has plans for smaller versions?GR: Yes, 4pt configurations can fly efficiently with the right controls.
We have not talked about newer/smaller versions but if this project is well received I am sure North Wind will be keen.

- The 4pt Z board is now being adopted in the Nacra 15, surely i nthe N17, you have designed latest Exploder foils and you have also worked in Americas Cup projects,
is there a chance to see the 4pt in coming AC for Bermuda?
GR: No. Rule 11.14 says the windward board cannot be used to increase righting moment. This lack of righting moment is what makes the current 3pt configuration better than the current 4pt configurations. I would emphasise "current".

- What about the board raise system, curved boards seems to have a smoother framework, and Z as seen in the As do have a special space required in the deck for fully raised?
The boards will end flat over the deck?
We have designed the tightest daggerboard trunk possible, so the way they are positioned is not a problem even for the interior. They do go a bit over the deck but this is something we studied and is not a problem. In the end when sailing, both boards will be down.

--- Ends --- Copyright , Catsailingnews.com

Press Release - North Wind 55 Catamaran

The Concept
The NW55 is a blue ocean cruiser designed for fast, comfortable and short-handed
sailing. The options available enable the boat to be used as a cruiser or as a racer.
A huge amount of work has been carried out to shape the hull , its appendages, the deck layout and the interior, in order to achieve our three main goals: speed, comfort and ease handling.

Appendages and hull shape
Designed by D3 Applied Technologies via a Computational Fluid Dynamics approach,there are two sets of possible appendages which are interchangeable: conventional curved or Z-shaped daggerboards. The hull shape features the latest trends in hulldesign with negative rocker aft and flat sections fore and aft improving pitch stability.

Deck plan
The two helms located on the deck, guarantee protection and perfect visibility. All the control lines can be
concealed under the deck all the way to the helm and the crew can all sit together while sailing. A full press
button option for the hardware is available.

Cockpit and interior
The saloon, which can be fully open to the cockpit, offers a 360° view and can include convenient options like a barbecue or a fish cleaning table. All the furniture is in a modern style and construction. Sandwich
systems are used and fit smartly with the structure of the boat to reduce weight while maintaining high
standards of comfort and top quality finish.

Sail plan
The sail plan features a square top fully battened mainsail, a self-tacking jib and the foresails of your choice. We will gladly share our knowledge and expertise to help you choose. It is well fractioned with the mast in the middle of the boat´s length, for easy handling, quick tacking and balance.

The Team
The NW55 project is carried out by North Wind Yachts, a long established monohull manufacturer and builder of the most sophisticated blue water cruisers in southern Europe. With over 40 years experience in boat building it has opened onto the Multihull market. NW has brought together a team of Multihull specialists, combining experience with a revitalized task force.

François Pérus and Romain Scolari are the naval architects of the project. Among their latest successes are the Pulse 600 and the Slyder 47, both nominated for the 2016 Yacht of the Year.

Jonas Hertwig works as a Yacht Designer and owns his own studio. He is responsible for the interior design and also did some “designer´s magic” for the exterior design.

Gonzalo Redondo, managing director of D3 Applied Technologies, designed the hull bottoms and the
appendages, and co-worked with the architects for performance optimization, using the latest hydrodynamics and VPP knowledge. Their experience in the foiling A Class, the Americas Cup and many other “flying machines” is a great asset to our team.

Isonaval, led by William Pegram, brought all the systems and production organization together. Their
experience ranges from racing sailing boats to super yachts, therefore smoothly handling a puzzle of a thousand items is absolutely no trouble for William.

Puerto Deportivo de Aiguadolç Local 23
08870 Sitges
Barcelona Spain
Phone: +34 637 745 439
Mail: sales@nwyachts.eu
Web: http://www.northwindyachts.com