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A Wing and a Prayer

In a show of solidarity, the Moth class has decided to allow wing sails at the upcoming Zhik Moth Worlds.

December 27, 2010
Sailing World

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Moth champion Bora Gulari tests his new wing sail. Courtesy Bora Gulari

“The Eagle has landed.”

Last summer, Moth sailor Adam May posted these words to his blog, announcing the successful sea trials of his solid wing sail, a first for the class. Since then, three other wing sails have appeared. Though they’ve yet to compete in a race, wings sails have created a firestorm within the Moth class. Sailors have shipped wing sails to Australia for the 2011 Zhik Moth Worlds, which begin Jan. 8, and the class has yet to decide whether the sails are legal and, if so, how to measure them.

Caught in the middle are American Moth sailors Bora Gulari, 2009 world champ, and George Peet, who have traveled to Australia unsure whether they’ll be able to race their wing-powered boats, built by Object 2 Skiffworks, the shop that produced the boats that won the last two editions of the International C-Class Catamaran Championship (Little America’s Cup).

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Established in 1928, the International Moth Class was created as a development class with just two fixed parameters, length (11 feet) and sail area (8 square meters). Over the years, the class has evolved from scow, to skiff, to ultra high performance hydrofoil speedsters. With the emergence of the foiling Moth, the once class has shifted from mostly homebuilt boats to production hulls from makers like Mach 2, Assassin, and Bladerider. The excitement of foiling and the ease of acquiring a hull have helped the class grow in recent years, and there heve been growing pains. The early Bladerider hull has been all but obsoleted by the more advanced Mach 2 hull, and if you want to win the Worlds, you had better be riding the most current hull. With boats now costing upwards of $20,000, the arms race can get expensive in a hurry. But such is the nature of a development class, where sailors are always in pursuit of the leading edge.

In early 2010, both Gulari and May had come to the conclusion that the next big development in the Moth class would be a solid wing, similar to those seen on BMW Oracle’s trimaran in the 33rd Americas Cup. Both set out to build wings. May debuted his in August; Gulari’s emerged in October. Object 2 built two more wings, one for George Peet and one spare. May’s wing has two main elements, while Gulari’s wing has two main elements with a flap attached to the main element. Since May is the class’s chief measurer, the Moth Class Executive Committee (less May and Gulari) was asked to interpret the rules to confirm the legality of the wing and determine how to measure them.

The class response was issued on August 12, but not published until November, and it created more questions than answers. Rather than rule a wing of any configuration as a single sail, the class deemed that a two-element wing is not just one sail, but a combination of a mast and a sail. This should allow May’s wing to compete, but what about Gulari’s? Here’s where the controversy gets interesting. If Gulari can prove his wing, with two elements and a flap, is a two-element wing, it should comply. However, if the class deems his wing as a three-element wing, then, as the committee stated, “the IMCA Executive Committee has discussed these types of sail/mast combinations and is of the belief that under the current class rules these would either be illegal (due to not satisfying the one sail rule) OR would have to be measured in their entirety as sail area.”

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This vague ruling caused a division within the class, with the anti wing camp—which includes builders of the some of the current Moth hulls—trying to ban the American wings, claiming they violate the one-sail rule and the spirit of the class.

The debate focuses on the definition of mast. Class Rule 8.1 states that “the overall length of mast shall not exceed 6250 mm.” The second element of a wing would then be considered the sail, constrained by Rules 8.3 (“The distance between the bands (effective luff length) shall not exceed 5185 mm.”) and Rule 9.1 (“The boat shall carry only one sail when racing, with the total sail area being not greater than 8.00 m2.”).

Based on a strict interpretation of these rules, it’s conceivable that a wing could be built with the first element one meter larger than the second element, creating a lot of unrated area. Rumors abound that Australians John Harris and Dave Lister were designing a wing that would take advantage of this loophole, but the wing will not be coming to the Worlds in Belmont. Both May and Gulari were aware of this potential loophole and agreed to build wings to the 5185mm height and a total area of 8m2. The real contentious issue with Gulari’s wing lies in the flap that is part of the first wing element. Some may see this flap as a non-structural piece that is allowed to deflect by aerodynamic forces. Since it doesn’t support the sail and produces lift, it must be considered a sail. Gulari disagrees, reasoning that, since there is no visible gap between the leading edge element and the flap, they must be considered as a single assembly. Since the class already allows camber inducers in soft sails, it would be counterintuitive to rule against similar camber-inducing mechanisms in a wing sail. Gulari further notes that, should his wing be deemed as more than two elements, the last paragraph of the rule interpretation allows for the wing to be measured, provided that the entire area is used in the calculation.

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The Moth Class Measurement Manual states, “Measurers should assume that anything which is not specifically prohibited is permitted.” Making the situation even more confusing is the fact that the Moth Class doesn’t control its own destiny—ISAF does. Since becoming an international class in September of 1972, the Moth class must submit any changes or interpretation of class rules for ratification by ISAF. To date, ISAF has not taken any action regarding wings. Given that ISAF already has experience with wings in both the A and C Class catamarans, I’m assuming that the authority will deem wings to be legal. But ISAF may choose to remove some of the vagaries in the Moth interpretation by mandating their own measurement rules for wings. ISAF’s guide to Measurement and Calculation of Sail Area has long been the basis for measuring C-Class wings in the Little Americas Cup, and it could provide some indication of how ISAF will address wing sails in the Moth class. Section 1.1 of the manual states, “The intention is to establish a reliable and simple method of measuring the whole driving area of the sail plan, including the spars, foils, and flaps (or wing sails).” Further, Section 16.2.2 (b) addresses flaps on wing sections, stating, “Devices or fairings added to a spar or wing sail shall be measured as part of that spar or wing sail.” Additionally, 16.2.2 (e) states, “An articulated wing sail, such as that shown in fig. [2] below, shall be measured as described in 16.2.2…”

In all of this debate, the one point on which nearly everyone can agree is that we want to know if a wing sail can beat the best of the soft sailed Moths. With wing sails taking over the America’s Cup, Moth Worlds will surely capture attention far beyond the class aficionados and tech geeks. The event has something for everyone. As Gulari says, “There’s a huge importance to the class of having this wing experiment go forward. Tens of thousands of people have seen the pictures and articles about the wings Adam and I have built for this event. Moth wings are what people are talking about, even people far outside of the class. Everyone has the same questions: Will it work? Will it be faster? Will it break? Everyone wants to know if a small wing sail will work on a high performance foiling dinghy. Let’s find out. Our class has a phenomenal chance here to solidify its reputation as the class at the leading edge of our sport where this sort of cool stuff happens.”

I commend the Moth class for doing its best to ensure that none of its members feels disenfranchised. But now’s the time for the class to embrace its historical spirit of innovation by allowing wing development to take place. By interpreting the class rule to assume that any single wing is one sail, and using the ISAF measurement procedures for wings, development can happen in an organic and transparent way. If wings prove to be durable and faster than soft sails, the marketplace will ultimately find a way to make the technology cost-effective and transportable, in the same way that hydrofoils went from expensive experiment to standard equipment. With top sailors worldwide looking to make their marks in the brave new world of wing sails, the Moth Class can become a breeding ground for future America’s Cup sailors, as well as a new generation of speed junkies. In nature, all moths must undergo a transformation. Now’s the time for the Moth class to come out of its cocoon and spread its wings.

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Update:

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ISAF has issued a ruling, saying that current Moth class rules don’t apply to wing sails. In response, Moth class president Mark Robinson issued an emergency questionnaire to member nations, asking them to pick one of two options on the wing-sail issue:

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1. Change the NOR for the 2011 Worlds to allow the two known wings (Bora’s and Bear’s Object 2 builds) entered to compete in the worlds.

2. Change nothing, which, according to ISAF interpretation, means our present rules will prohibit use of the wings.

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_The class responded with a solid voice. “The Presidents of all national associations have responded with the vote being 30 in favour of Option 1 and 6 in favour of Option 2,” said Robinson in a statement. “We will therefore be proceeding with issuing an amendment to the NOR under the guidance of and with approval from ISAF. Chief Measurer Adam May is currently working with ISAF on the final text and I expect this to be released shortly.” _

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So the wings shall sail. Expect to see something special beginning in 10 days. Based on the results of the Worlds, the class will then be faced with the more difficult decision of whether to ban wings, or revise the class rules to allow for their development. Expect more fireworks to come!

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