Starting this month Luca Devoti becomes a contributor to both Farevela.net and FareVela, Italy’s biggest sailing media. The Italian Olympic sailor, silver medalist in the Finn in the Sydney 2000 Olympics, skipper of +39 in the 2007 America’s Cup, founder of the Devoti Sailing boatyard that builds Finn, Melges 24 and D-One, and current coach of the Italian Sailing Federation at theFinn class, will talk about various topics related to competitive sailing, fruit of his long experience and his wide network of international contacts at all levels. A well-informed person of the facts, as well as a careful observer of what is taking place in the sport of sailing.
In this first installment, Devoti gives a critical view on the current America’s Cup and, in particular, the AC72 yacht which he considers to be an example of the “complete lack of practicality” that, in his opinion, marks the 34th America’s Cup. Devoti has first-hand experience on the issue, having been the Sports Director of Green Comm Racing, the now defunct challenger for the 34th America’s Cup:
AC72 … a triple leap of faith
The problem with the AC72 wings is mainly logistical, the ability to manage and handle a piece of equipment that weighs many kilos in order to make it operate in the best way possible within the complexity of configurations that will provide the aerodynamic advantages for the best performance. All teams have positioned themselves towards a three-element wing, with three modules and a central part, the same path the Little America’s Cup had already taken. The difficulty lies in making it work and turn, by changing its shape while using the least energy possible. We must, therefore, understand how the wing works. In the AC45 the key lies in the use of the winch that is connected to the wing and serves as sheet and runner, making the windward hull fly at an ideal height, neither too low nor too high. This is in fact obtained, especially when the wind is unstable in intensity and direction, by continuously trimming the wing in and out. On the AC45 this is done with a load that is manageable by one person with a winch, although with great difficulty. We have seen that the ideal wing trimmer is a great sailor but is also in great physical condition, especially when the wind picks up.
The load on the AC72 wing, in this sense, will be much greater, I don’t want to be wrong but I think it will be around 1,500 kg, and will, therefore, involve different sizes and approaches. We must see whether we succeed. If you remember this was the problem of the challenge of the two monsters in 2010, that is the advantage of Oracle USA 17 over Alinghi 5. Alinghi struggled to stay high and with a certain angle, it was not a problem of quality of the helmsman as much as the difficulty with a conventional sail to keep this ideal setup. The wing has therefore only a lateral load and still very low compared to the load on the sheet, and in a conventional sail when you ease or tense the sheet, it opens, twists more or closes. This type of work, especially when made with an engine, was perfect … one got there … and inside-outside, inside-outside you trimmed. On the other hand, with a conventional sail, even with the help of an engine, it was very difficult. Therefore, perhaps, we might see wing configurations that don’t seek maximum efficiency, but maximum ease of use.
Given the race course and the venue (the windy bay of San Francisco) a lot of unknowns open up in this project. The wing is so high and in San Francisco with 25 knots of wind and steep and short waves, its dimension becomes critical. It works in theory, when the boat is at speed, because the appendices that will go on the AC72 will not be linear but curved, they will not be at a fixed angle any more but move in and out and could also change the angle of attack. The balance, therefore, is given by the dynamic lift, given by the shape of the bows and the angle of the front foil, however it is clear that if, for any reason, there is no speed, the dynamic element will be missing and the possibility to pitchpole will increase exponentially.
I spoke with Paul Cayard in Valencia, I talked to others and they are all worried because they do not know exactly what will happen. The forces compensate each other in theory but it is a dynamic equilibrium, not a static equilibrium, and the fact that it is a dynamic equilibrium will require helming the yacht very carefully. It was seen in Naples as well, where Artemis bore away without speed and pitchpoled. Imagine if they had two more meters of wing, it would have been even worse, so this leads us to a no territory, an unknown territory… You might need to slow down in order to avoid t-boning somebody and then what do you do?
The approach we mentioned earlier will be with the grinders and a wing built in such a way that will allow the easiest possible trimming. There are various ideas on the table and we will see which one is the most efficient. Another problem is the combination of the wing with the soft headsails, the gennaker and the spinnaker. In that case, sizing will be decisive. For example, Artemis that stepped an AC72 wing on their test trimaran, after finding the usual loophole, have a hoisting time of their gennaker, in light breeze, of 30 seconds. This, obviously, will not be the hoisting time with 25 knots of wind when the boat is doing 25 or with an apparent wind of 40 knots…
There we will have to see how long it takes to hoist it and it will have to be hoisted on a rail because otherwise it would be flapping all over the place, breaking everything… so, there is a series of very important management issues. In addition, when there is a capsize, we will need to limit the damage and therefore be very careful with the engineering and the construction of the wing, in order not to destroy everything or cause structural damage to the yacht when she’s up-righted… So, it’s a triple leap of faith in a complex and fascinating world.
The first-ever AC72 wing built was of Artemis Racing, Challenger of Record for the 34th America’s Cup, Valencia, 13 March 2012. Photo copyright Pierre Orphanidis / VSail.info
If there is one criticism to be made regarding this America’s Cup it’s the complete lack of practicality. The wing is hardly a sailor’s device, it is dangerous and if a gust of 40 knots suddenly comes, I think that the only solution would be to jump off and let it be destroyed… you can’t lower the sails, you have this wing 45 meters high and I think that you would capsize even if you were head to wind. Let’s make it clear though, all that is enormously exciting as well. However, the estimated cost of such a boat, of those dimensions, including the wing and the foils, is over 11 million euros. The truth has to be told, the costs are crazy and this forms part of the lack of practicality we mentioned before. We have very few teams, enormous management difficulties and costs that soared, in a financial period like this. An old ACC cost 3 million euros, this one costs 11 million and breaks much more easily. That’s what created the problems the teams are currently trying to address.
Of course, when you’re onboard it’s fantastic, even on the AC45′s it is really fun and demanding. You have to change completely your way of thinking: the boat is sailing from the moment the wing comes out of the shed because the wing can fly away at any moment. From that moment you must handle it in a certain way, with many people, you must look at the wind in order to know when to lower it or when to lift it. You must leave the boat with the rudders set in a certain way to ensure that she is oriented according to the wind when there is nobody onboard, at least until the wing can once again be removed and stored in the closed shed, which is the time when sailing ends. All that is very stressful, it is an object that requires a lot of quality people. As I mentioned it is a leap of faith for all, since there isn’t any expert on winged catamarans of this size. We will have to see, shortly, if all this works …