New AHPC F18: Brett Goodall interview

I asked Brett if he could give us more details about AHPC new F18 and he kindly took time to respond this new launch. Many thanks to Brett for full insight answers.

CS:Why did AHPC decided to build a new F18?
Brett Goodall: Commercially the CAPRICORN is has been on the market for 5 years but the design it’s self is even older. Since that time we have learned so much about the specifics of what makes a fast spinnakered catamaran. We are at the stage now where we have developed enough knowledge to produce a new F18 that is truly be better than everything else out there.

Who was involved in the design process?
BG: Every sailor who has ever provided feed back to AHPC. We spend a lot of time and analysis to create solutions consistent with this. More directly though, responsible for this analysis and creation is Greg Goodall and myself. We have been competitively sailing the in the class for the last 5 years and know firsthand the how the boats behave, react and handle.
Greg’s reputation speaks for its self, he has designed boats for the last 40 years and even his Moth designed at the age of 16 was a revolutionary championship winning design. His rigs are some of the most innovative and fastest in the world.
I have brought a new generation of design capabilities to the process. Falling in line with my university studies, as a designer and engineer, we were able to utilize the latest in CAD and Engineering software. We actually used the same CAD software used by Boeing and manufacturing used by Toyota.

Do you already tested a prototype? If so how many hours do you estimated on testing and design?
BG:We are always looking at new ways to improve our designs, so fundamentally we are always testing systems and ideas. The VIPER was used as an opportunity to test new ideas and prototype these. I think it is a safe assumption to say they worked.

Which are the benefits of that “cut out” bow?
BG:Interesting that you refer to it as a “cut out”, comparatively we haven’t removed much bow. The idea of the stepped bow is to produce better shape in the first 30% of the hull. This improved shape allows a more even volume distribution and smoother shape in the bow creating a more direct flow over that section. The new BMO floats have a similar shape to them, but our models where finalized before these came out.

Rear beam will be elevated or integrated to a higher deck as the renders show?
BG:The beam will be integrated just as the renders show; however it’s still significantly higher than the CAPRICORN. The square transom shape will also have the beam sitting higher off the water. During the design process we decided the best position for the beam, looked at a few options and then decided to build the deck up to it instead of having pads. Building it this way means we also raise tramp and skipper, and utilize platform stiffness.

It will have more volume than the Infusion or Shockwave?
BG:The simple answer to your question is no. Generally speaking adding volume adds a lot of drag to the hull; just building more volume into a hull is an uneducated way to solve a problem, and it may not actually even solve the problem. Our design criterion was to change the volume distribution through the hull to improve the handling without drastically increasing the drag on the hull. These theories where tested on the VIPER and they worked on a boat 2 foot shorter so we employed similar theories to this design.

The Cap is already a performer, what did you try to improve from it? bow volume perhaps, and more error margin downwind?
BG:This design process wasn’t a case of improving the CAPRICORN; we took what we knew from the CAPRICORN and what worked on the VIPER and combined them. Downwind performance in heavy conditions was definitely a weakness of the CAPRICORN and it was high on the list of requirements for this new design. If you where to directly compare the new F18 to the CAPRICORN there is a lot more bow volume but it also has a number of other features to improve the downwind handling including the transom shape. Aside from the obvious, one of the major changes is the main beam has moved back behind the halfway point of the hull, this shifts the entire rig weight back as well giving the boat more bow than any other F18.
Although we have always been developing our rigs, the new hull shape will allow us to fully optimize it within the F18 rules. This means maximum height, maximum head size etc.

The Capricorn will still be offered? Of course in Argentina you are launching it for South America, what about the rest of the market?
BG:As you know there is an altered CAPRICORN licensed and offered in South America. We will definitely continue supplying all parts and all servicing for current CAPRICORN owners, even to the extent that Greg is finalizing new 2010 sails for it. We will be also able to supply hulls on special order only if required.

That flat bottom stern was there on the Viper first, then the Hobie WCat adapted that feature too, you were the first in using a stern that flat? benefits?
BG:The theory has been well established and used on dinghies for quite awhile now. It’s simply creates a low drag run off at the transom. The shape means the hull doesn’t depress as far into the water to have the same amount of buoyancy. This also has the added benefit of better fore / aft (hobby horsing) stability.

Overall volume is bigger than your current F18 right? As previous Wave piercing designs took a lot from it, did you get that feedback and evolution back in other boats (ie: Infusion, Wildcat, Shockwave) to your new design?
BG:For sure!! We are always gaining information from any source and there is no better way to do that than from other designs. We look at what works and what doesn’t and we have to know why, and then figure out how we will do it better. It’s actually a great source of information; you’d have to be a pretty arrogant designer to do otherwise.

Which the time frame for a commercial launch in Europe and USA?
BG:We will have our official launch at the Paris boat show in December, and will be fully delivering into Europe by February. Local dealers will be able to assist customers on exact dates and availability.

Final price is going to be the same as the Capricorn?
BG:Pricing TBD at Paris with the confirmation with the whole design

Thanks again to Brett for his disposition and keep tuned for more info about this new F18…
www.ahpc.com.au