Writing the Rule
Writing the Rule
Gino Morrelli and business partner Pete Melvin have been successfully designing state-of-the-art multihulls for a very long time, but other than their involvement in the 27th edition of the America’s Cup, which saw the Stars and Stripes catamaran win its defense against the Kiwis, they’ve been absent until recently from the AC scene for obvious reasons. They were seconded by Oracle for their (successful) 2010 challenge against Alinghi, and this go around, the M&M team participated in writing the new AC72 Class Rule before being hired away by ETNZ to design its AC72. Pete joined the team in New Zealand, while Gino has been holding the fort in their Newport Beach, Calif., office and been peripherally involved with design team meetings.
Morrelli’s hot on foiling as the way to go forward in all things AC. “Most people don’t realize we’ve been dealing with foiling for almost four years, before the 2010 Cup," he says. "We designed the Nacra 20 that’s been in production for five years now, that had curved foils; prior to that we built an A-Cat with curved foils. We’ve been building power cats for 15 years with foils. People playing with catamarans have been playing with foiling for a long time.” We caught up with Morrelli for his insight on the big picture of the AC72 design:
The 72 seems to be a designer’s dream and a sailor’s nightmare. How did you get to the boat we have today?
GM: Most of the 72 was dictated by Russell [Coutts] and the Oracle guys. After the 2010 Oracle campaign, they retained us [morrelli & Melvin] to do some performance analysis on different sized trimarans— a trimaran being the original contender with a soft rig. We did all kinds of analysis on things from 60 to 90 feet—cost estimates, performance estimates, and providing them with a matrix of options there.
The cat was part of an early allegiance to move boats from one country to another—de-mounting boats and shipping boats on planes around the world—cats would simplify this craziness, [with] less parts. The transition to the wing on top of it—there was no real research done on our part—was just like a declaration by Oracle, “We want a wing. Tell us how big a wing we can put on.”
Then, they constrained us with needing to fly a hull in 6 knots of wind. Once the boat size was determined, it determined the wing size by the requirement that it had to fly a hull in 6 knots of wind—that opened up the whole Pandora’s box of the rig being really big for San Francisco. That’s where the idea of two rigs came about—big and little—with the rig committee determining the night before the race which rig people would have to use. That got dismissed because of cost and management problems. The next idea was to put a removable top on the rig—15 feet off the rig—but the harsh reality of taking tops of rigs with control systems, etc.? Not really. So we ended up with the big rig for all purposes all the time. Due to cost and complexity, the idea of an alternate smaller rig also went by the wayside. I think it was one of those situations where Oracle ran out of time, and it was either do nothing or mandate a whole lot of expense. Everybody knew you’d end up with a boatbuilding team and a wing-building team. The two never really cross over very much—you end up having to babysit the platform with a set of guys and same thing with a wing—it now takes 35 guys to launch a wing.
Let’s assume multihulls carry on into AC35. What will follow the AC72?
GM: I think the excitement that has been generated in this Cup has way more to do with foiling and flying than the wing. If we used the same platform with soft rigs and rotating masts with fully battened sails, then first you can reef them, second you can launch them at your leisure like a normal boat, and third you eliminate the wing-building team and the problem with the handling of the wing, the hydraulics, and control systems. In reality the difference between the performance of the boats with a wing on foils and without the wing on foils, won't be much. They’ll still sail at 40-plus knots. Maybe they don’t sail at 165 degrees downwind, but at 163 to 160, and they’ll probably still fly in as little wind.
When we did the ’88 campaign with the soft rig and the hard rig, the delta between the two boats in the end was only about 1 or 2 percent, which is huge if you’re racing those boats against each other. There is a lot of economic push to go back to monohulls because there are guys sitting on the sideline that got pushed out in 2010. In fact, when we were developing the Rule for AC34, we’d get calls like, “Well, how many guys are going to be on board?” or, “You’re not going to put that engine on board are you, because that’ll displace about eight guys.” Some of these guys had made their livelihood off the Cup for 30 years.
Trimarans of 2010, photos: Gilles Marin-Raget/BMW Oracle Racing and Carlo Borlenghi/Alinghi
Should the boats continue to foil if multihulls remain?
GM: I think it’d be a travesty if they didn’t foil. All they have to let us do is articulate the rudders, put flaps on, or articulate the rudders and angle the tack, and these boats will get way faster overnight. The benefit that we’re tapping into right now is just beginning. Back in ’88 I was involved in researching the defense of the use of catamarans in one of the court battles. One of the things we learned was that George Schulyer who wrote the Deed of Gift, sailed a catamaran. The naissance of the America’s Cup has much more to do with the American defense program. The Cup was taken from England when we were just a baby of a country compared to England. The reason that the AC victory was so fundamental at the time was that it was a breaking out of American ingenuity and technology, challenging the English. The DofG was an attempt to create an event that promoted naval architecture for American defense as it was for a yachting competition, at a time when domination of the sea controlled your security for trade and prosperity—all those guys were nation-builders back then. It was the space race of the time. That’s what the Cup is.
What’s your opinion on the subtleties of the hull shapes?
GM: They almost don’t matter anymore. Even upwind, unless you’re sailing in 2 knots of wind, you’re always trying to generate a bigger fraction of lift off the daggerboards. When we first started with ETNZ, the only tools we really had that were highly developed were all based on monohulls. It took about 3 or 4 months before the CFD tools got sophisticated enough to start accounting for daggerboard lift because it’s a very interesting mathematical problem to analyze a hull that goes from fully immersed in displacement mode to flying in the air. The whole drag curve tradeoff with the size of the foils, the position of the foils, angle of the cant—all that had to be developed. A big matrix of hull shapes was generated, and we looked at every boat that was relevant in the last 3 or 4 years, whether it was an A Cat, a F18 or F20, anything in that genre, and ran it through the CFD. In the end, from the best to the worst it was like .5 percent. There wasn’t any giant delta to be won or lost. After going through 50 to 60 boats, the fastest hull shape was basically an existing boat. The joke was, “Don’t let Grant know because he’ll fire us as we’ve just spent four months trying to find a better hull shape and we couldn’t.” The whole idea of hull shapes being important has been superceded by how important daggerboards are and foils are. We joked that the hulls had become “board delivery devices."
It was suggested that ETNZ’s hull shape probably saved them from a worse fate in their recent nosedive?
GM: With ETNZ’s recent crash, the hull shape did come into play, but it was the volume that was important, not the shape. The only important decision with the hull shape design was how much bow you stuck in front of that daggerboard to accommodate for any crash, and that’s where you see a delta between the shapes, between Oracle, Artemis, and ETNZ—how big a bow to stick on it to survive the inevitable which is what happened to Oracle when they capsized. Both teams did a weather hull pitchpole. We’re not capsizing over the leeward hull, we’re starting to capsize over the weather hull, which is a completely new way to capsize a catamaran. The hull shapes are not going to determine who won or lost the America’s Cup by a long way except for the lack of survivability—the nose—Oracle’s a lot finer, a lot narrower in the front, and we’re a little fuller and taller. We carry around the extra windage and a little more weight.
You and Pete were part of the team who wrote the Class Rule then went on to design ETNZ’s boat. What was the benefit to ETNZ?
GM: Obviously we had an insight as to why it was written the way it was. We were directed by Oracle and Mascalzone Latino to address any particular fundamental issues, like hull point speeds, weight, crew limits, that sort of thing. It was very much a big group working together for months. Like any group decision it’s never perfect. It’s a bunch of visions pushed together with certain compromises. We [Melvin & Morrelli] took a bit of a different path—we had about six of us in our office who were involved in the Rule writing, so we divided the office in half, with half the team writing the Rule and the other half troubleshooting the Rule. For example, Pete was writing the Rule, and I was on the other side challenging the Rule.
One of the jokes in-house was that we were very wary that we could write a rule and have a loophole in it that we would not be aware of, and once it got published we were particularly concerned that someone like Juan K. would read the Rule and interpret it to the point where he’d find a loophole and someone would somehow magically come out with a Rule-beating boat that somehow we had never envisioned. So we were always saying to ourselves, “How would Juan K. read this?” In the office we would force internal argument about the definition of every single line because we were trying to define something that didn’t exist, that was new.