30 knots in a 40-footer
by John Curnow, Editor, Sail-World AUS 24 Jan 2021 21:00 GMT
MW40OF - New Foiling Offshore Sailboat Concept © Wilson / Marquinez Naval Architecture
Lower attrition than normal cannot disguise the fact the Vendée Globe has been utterly captivating. Extremely close racing with what seems like daily lead changes have been key to it all.
Another irrefutable fact in the whole thing is just how much the Vendée and the America's Cup have been sought out and read across the Sail-World and YachtsandYachting.com group. Foiling, and the pace increase on offer, have been pretty hypnotic. Yet it is when applied to the venerable monohull that we have seen a kind of carnivorous appetite, and it is for this reason that items like, I feel the need... and then, Speed = Smile on the Dial, have had terrific readership.
One item that had a real go at melting the servers when it first hit was the MW40OF - New Foiling Offshore Sailboat Concept. It is from the pens of Argentinean Naval Architects Laureano Marquinez and Nahuel Wilson, who also brought us the 69F, which is being used for the Youth Foiling World Cup this February.
Laureano Marquinez wrote back to us at the time confirming it all, and said, "We had quite a bit of response about the boat in general." He was also good enough to make time to respond directly to our questions about the boat and the project, which is what follows on now.
Sail-World: If a client pushed the button now, how long would it be to get to production?
Marquinez: "The boat is thought of as a custom-made, and one-off design. For sure there should be some time to adjust the big variables, but being a custom boat and hull shape influenced by the fact foiling is one of the primary objectives, the hull mould could be started relatively quickly. Probably between a month and two. Then more time would be spent to go into the details related to foils and systems, which must be set to some degree before allowing to define deck shapes, and a detailed hull laminate."
Sail-World: It is very challenging to meet all the issues around the multitude of variables that exist: rating, wave height, low rider performance are just some, as are static stability and overall mass, as well as the entire aero package? How many man-hours went into your calculations?
Marquinez: "Yes, it certainly is. Foiling doesn't let you leave anything to chance although nowadays non-foiling grand prix vessels are very much like that too. Still, foiling is a further step into design complexity as management of variables/decisions and building timeframes gets pretty intricate."
"Especially so if you want to end up with a tidy, nicely packaged design. We have spent probably a good two months of work to put the concept together, whilst studying the main variables we had, and to check what such a boat was capable of doing."
Sail-World: As 40-footers are becoming more interesting again, due mainly to rule changes, what sort of price premium will an owner have to pay?
Marquinez: Maximising foiling capacity comes at an expense, obviously, as you must push all the way into weight savings. Plus you have the extra cost of foils, systems, and the associated big righting moment. However, we made an effort to place this particular boat as a terrene possibility in regards to foiling options. The idea is to be around USD1m, although quotation is currently ongoing."
Sail-World: What sort of performance advantage can the owner and crew expect - either straight line, or elapsed time for key passage races?
Marquinez: "Focusing in on our performance when foiling, a reference against a current 40' offshore non-foiling racer is as follows. At 12kts TWS we start to foil reaching almost double the speed. Also, at 12kts TWS, but 120 TWA we should still be up on the foils with a speed delta (bonus) of about 6kts."
"Then as the wind increases it will expand foiling speed figures towards more closed TWA, and more downwind TWA. For instance, at 16kt TWS and 75 TWA we should have transitioned into upwind foiling with deltas of 10kts against the reference boat."
"Under the same wind strength, but at 125 TWA the potential speed delta is already at 14kts with our boat doing 25kts+. The further the wind increases these figures expand and at 20kt TWS we should do 21kts+ boat speed at around 65 TWA, thus with a speed delta of more than 10kts. Finally, at 130 TWA and with boat speed near 30kts, speed delta goes out as far as 16kts."
"Of course, all these figures are ideal, and sea state will affect at some point the capacity to get the full potential out of the boat. Yet there's clear potential to do what we aim for, not forgetting the idea of doing all these with a relatively small and simple boat."
Sail-World: Given that IRC and ORC don't really rate foilers as yet, how is the political scene for you in trying to get this on the table?
Marquinez: "Being such a novelty, we don't know how it's going to be managed, although we know they are already working on it. Still, it's our belief that there will be a growing interest, and then along with that, the will from the rules to incorporate it."
"It's a challenge of course that likely won't go in the direction of the foilers in terms of rating, due to the exigencies to keep up with a rating that very likely will see this boat as a potentially impressive performer. However, we think the interest in such a boat goes beyond winning on corrected times. One that incorporates a new way of sailing on mid and long-distance races, thereby allowing crews to compete in the races they used to do with a potentially much faster boat in the water than the fleet of their size range, all with the additional thrill of foiling."
Sail-World: The docking variable precluded an AC75 style over the IMOCA style, but what other variants did you review?
Marquinez: "Apart from the docking requirement we imposed on ourselves, we wanted simplicity beyond anything else, and to avoid hydraulics and flaps, as long the foiling range we intended to have was achieved."
"We also wanted to make sure the configuration was forgiving to ride in waves. A round foil is a proper compromise for all this, we did study variants to such a foil, but the answer to this particular project was pretty straightforward."
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John Curnow
Editor, Sail-World AUS