The Fledgling Eagle 53 Catamaran, by Jim Brown

Hello it’s Jim Brown here in the spring of 2019 with the story of the hatching out of the new Eagle catamaran. A portentous new bird. Call it natural selection that has given her a combination of mutations which I think really speak to the future of marine architecture. She combines the radical but practical new sailing rig called the hybrid wing with two types of hydro foils in a very advanced modern multihull We’re gonna catch her just as she jumps out of the nest, hoping that that will bring us as close as possible at this time to the very leading edge of multihull development. But her forebears that produced these mutations were a couple of smaller multihulls that we’ll have a look at first This is Caliente the Spanish word for hot. She’s a forty foot racing catamaran that was used for the second of three prototypes produced by Fast Forward Composites and their quest to develop the hybrid wing rig. Tommy Gonzalez generously invited me and Scott Brown to sail in this boat in the fall of 2017 Scott was able to take this picture from his chase boat, and others from onboard, which I would like to use here in order to illustrate a few of the basic features of the hybrid wing. That’s me there in the yellow slicker holding my breath. It was the first time I’d ever been sailing in a boat that intentionally was flying the hull as much as possible. Actually I loved it, we were way up out of the spray. Randy Smyth was there as Tommy’s test pilot. He was in a position where he could see the knot meter. I asked him how fast the boat was going? He looked down, casually said “oh, 26”. And that’s without hydrofoils Anyone with an eye to aerodynamics can see the incredible efficiency of this very tall high aspect rig. Here’s a closer look at Caliente’s hybrid wing First of all, I’m sure you’ve noticed how beautiful and cool these structures are They are so off the wall that they deserve a bit of explanation. The big solid black leading edge is all carbon fiber. It’s hollow, of course, and has the section of a giant letter D with the straight back of the letter D forming what they call a shear web, a long piece of tube of this description becomes extremely strong and stiff when bent across the shear web and it’s that lateral strength across the beam that becomes so important in the case of the hybrid wing where its cable staying goes all the way to the tippy-top. Of course this creates an enormous span running all the way from the deck to the top of the wing, 65 feet unsupported by other rigging. So the only way one could approach a structure like this is with carbon fiber. To complete the giant teardrop section there are wing frames that extend back from the D section to the trailing edge and it’s that portion of the wing that’s covered with this transparent Clysar film It’s gin clear and transparent but of course as far as the air is concerned the frames and the transparent portion of the wing go together with the D spar to complete the teardrop section. And to comprise the trailing edge of this wing there’s another carbon fiber beam that runs full length to form the terminus for the two sides of the wing frames. And mold it into that terminus is the internal sail track for hoisting and lowering the soft sail element of the wing. This is the downwind side of the rig in action and it shows the wonderfully fair and almost seamless transition across the rigid wing and onto the soft sail. By lining up the wing frames with the seams in the sail, one can see a continuous curve except notice at the very top a slight bit of twist off. That is, the soft sail is trimmed a little slack toward the head and down at the bottom the soft sail is very slightly over trimmed. There’s a reason for that. Now let’s look at the upwind side of the rig. To me, this is one of the most interesting photographs It shows the flow lines even on the upwind side of the rig. looked at the transition between the rigid wing and the soft sail is also here almost totally fair. There is very little bust in the flow lines between the rigid and the soft element. But again notice that the soft sail element is twisted from the bottom to the top. And that’s because, in all sailing rigs, the wind velocity is greater at the top of the wing then at the bottom. And unlike in the totally rigid wing rigs such as in the America’s

Cup boats, which would have as many as three ailerons on the trailing edge of the wing, all of which have to be individually trimmed by the poor guy who is the wing trimmer, in the hybrid wing the trim angles in the soft element are continuous and they are achieved automatically, which is a great simplification for the sailor. And here is the crux of the whole matter. We’re looking up the leading edge of the D spar, the rigid portion of the wing, and at the tippy-top notice the three-cornered hat. And extending down from those three corners is the cable rigging that supports the entire mast And because the rigid portion of the wing is narrow at the top, like a feather, when the soft sail element is removed that rigid wing can rotate 360 degrees inside of the rigging that holds it up And in fact this view shows the wing rotated about 180 degrees with the breeze coming over the stern of the boat Of course the three-cornered hat does not rotate and those synthetic cables leading away are the shrouds headed down for the outboard ends of the after cross beam. There are bearings at the top and bottom to allow the wing to rotate almost effortlessly so that it can aim this leading edge that we are looking at directly into the wind from any direction No human attention necessary. The wind engine stays in neutral until the crew wants power. So the first prototype hybrid wing sail rig was featured on Randy Smyth’s little trimaran Sizzor in which he won the radical endurance race called the Everglades Challenge. This was my first sighting of the hybrid wing and it was the first time the invention was publicly disclosed. Randy was finishing the Everglades Challenge Race, March 2017, and notice please that he is coming in reefed. Right, the soft sail element of the hybrid wing is shown here halfway down. That’s it’s only reef point incidentally, one is all that’s needed, but imagine: a reefable wing sail! And that combines with several other advantages. For instance, far less physical loads on the boat such as about 40% less physical loading on the mainsheet, then somewhat higher pointing angles when sailing into the wind. And then greater thrust forward for a relatively less heeling effort. In fact, when reefed like this the wing can be trimmed to actually generate heeling effort to windward while the reefed soft sail still drives the boat forward. What we’re looking at is a new implement for seafaring. And incidentally, Randy won the race by hours. And as we’ve just seen the second prototype hybrid wing was on the 40 foot catamaran Caliente, where incidentally, it has since proved itself strong enough to withstand capsizing the boat. And furthermore the buoyancy inside the sealed D spar of the hybrid wing prevented the boat from capsizing all the way, turning turtle, which I think is a harbinger of the multihull future. And the third prototype hybrid wing is of course now sailing on the 52 foot catamaran Eagle. But before we go flying off on hydrofoils in that bird let’s have a look at her as a fledgling. In fact I had a chance to see her as she was pecking her way out of the egg This is the nascent Eagle alright on exhibit at the Annapolis Boat Show October 2018. Note the long wave piercing bows. The carapace is that white panel on top of the cockpit and the hybrid wing coming down on top of the carapace I thought this little model was the star of the show. The model sits here on her T foils. Note that the main T foil is about in line with the hybrid wing and there’s an enormous cantilever of bow out forward. The main horizontal lifting foil supports most of the weight of the boat and to the left the rudder T foils are much smaller primarily used for maintaining longitudinal stability We can’t see it in the model but the trailing edge of this underwater wing would be fitted with articulating control surfaces such as flaps or ailerons. Close up of the rudder foil shows a much smaller horizontal portion And it’s these little foils that follow the boat like feathers on an arrow

Minute changes in the boats pitch angle cause sufficient change in the angle of attack of that little foil to provide the boat with longitudinal stability. And of course for directional control that whole thing steers, that is the rudder and there are two of them. As rudders go these are wonderfully deep with very high aspect ratio. Here are the fellas That’s Paul Bieker on the left, Eagle’s designer. In the middle is Tommy Gonzales, the honcho at Fast Forward Composites where Eagle was built. And on the right is Randy Smyth, the test pilot world famous sailor. Taken at the Annapolis Boat Show October 2018. Let’s hope that in 2019 they can show the real boat at Annapolis. She will certainly distinguish herself from the other exhibits. Well let’s jump ahead to January 2019 and here she sits in Derecktor’s shipyard in Fort Lauderdale Florida Tommy shipped her down here to get out of the Rhode Island winter and break out of the egg. We’re looking at the starboard stern from down low and the carapace is exaggerated in this view. And note how the C foil curves upward over the boat when retracted. Let’s just walk down along her starboard side here. Have a close look at that yellow thing underneath the boat in the shade that’s the sail drive. It’s like the lower unit of an outboard motor but there’s a diesel engine inside driving that propeller. And you’re right, the weight of the engines is just as far the middle of the boat as they can get it. Well we’ve come to the starboard bow. Right, that’s the bow! They’ve got a towel stuffed in the hawsehole up there, I don’t know why But have a look down along the topsides of the vessel. You can see the reflection of the building in the background, heh It’s beautifully fair incredibly well built and clean Randy Smyth says “there’s not a bump on it”. But this is the reverse stem wave piercing bow. You can see both the port and starboard C foils in this view, sticking way up in the air over the boat Okay, let’s look across at the portside bow. See it? It’s way over there. This boat is really wide. And that big black cannon is the bowsprit. It’s propped up there on that plywood jig> Now unlike a trimaran, this boat does not have another hull in the middle It’s a catamaran, not a trimaran, so the designer has to put something to which he can attach stays, the cable standing rigging that leads up to prevent the mast from falling backward. And of course these stays are now made available for carrying head sails, jibs. And those stays create an enormous upward load, a stress pulling up on the bowsprit. Something has to oppose that load. Here’s what does it We’re looking down through the tunnel between the hulls and this bow like thing on the left is in no way a third hull. They call it the pod, P O D. It’s a massive carbon fiber laminate that runs all the way to the aft edge of the bridge deck. The guys are installing the bow net here, that’s why all these strings hanging down. Just out of view above the net is the bowsprit. Down at the very bottom of the pod at that knuckle, note there is a large black rod leading out of the picture to the left That is the bobstay. And it leads out to fasten about two-thirds of the way out the bowsprit, and that’s what opposes the stresses of the jib stay pulling up on the bow sprit. Of course that bobstay gets very tight under sail and pulls back on the bowsprit so the bow spirit is being shoved back hard into the boat above the net at the top of the pod and the bobstay is pulling forward hard at the bottom of the pod so the pod itself has to resolve those stresses. Hey now we can see the bowsprit where it plugs into the boat above the net and the bobstay coming off of the very bottom of the pod. And just imagine under sail an enormous upward strain on the bowsprit with just the bobstay to hold it down, with those opposing forces resolved in the pod. That’s why it’s so massive. And also we can see the flattish bottoms of the hulls. Hey this Eagle is gonna get her feet wet. I’d like to say a word about the shape of the hull. What this shape does is it allows the

designer to get displacement, get buoyancy down low without going deep. It reduces what we call rocker, the bottom of the hulls resembling the runners on a rocking chair. And that old-time hull form tends to concentrate buoyancy amidships, whereas we’ve learned that if we can spread the buoyancy out toward the ends of the boat, so much the faster. The so-called prismatic coefficient. And this hull becomes even a little flatter as it runs aft and that of course generates lift at speed and can help a hydrofoiling boat to break out of the surface, that so-called takeoff window as she gains speed and the foils try to lift her up out of the water. She’s going to be coming in and out of the surface at times and that transition cannot be too abrupt or the boat’ll pound. This view from down low looks upwards at the underbody way forward near the bow. That oval boundary described by the dark bottom paint, that’s an accurate computer-generated picture of the water line around this hull. And despite the fact that the prow up high is razor sharp the waterline as described by that ellipse is rather broad. This tells us that there’s lots of buoyancy down deep at the waterline which is the exact opposite as would happen in a traditional boat where there’s lots of reserve buoyancy located way up high near the deck and overhanging the waterline. It’s there to help the boat climb over waves, whereas this hull form has active buoyancy down low and in service, with much less volume waiting in reserve above the waterline This is a hull form intended to pierce right through the crests, not requiring the boat to climb over, the so-called wave piercing bow. A whole new religion in marine architecture. And for a guy like me who came up as a schooner bum, it has taken me some time to become a converted zealot. I’m telling you, you have to see this thing in action spearing its way through a seaway to come around to thinking that it’s really beautiful. And look at how much hull, how much volume is waiting just above the waterline. So if the bow does try to rise, the stern cannot be dunked It’s the stern that keeps the bow down they’re puncturing the waves It’s like Jack London and his old boat the Snark that he said had a bow meant to punch storms. He had never seen anything like the Eagle Wolfgang’s gang is working on the boat day and night and I caught him at lunch hour to get up here and take some pictures so we can see the underside of the carapace here overhead. And note the closed channels which allowed the running rigging to be completely isolated from the people on the bridge deck. And those channels lead forward to the vertical pylon, the wing step pylon So the hybrid wing is stepped on the top of the carapace above that pylon, so all the running rigging runs through those channels and then down through the pylon to emerge at that cluster of witches on the nacelle. It’s a vast improvement from a common situation of having running rigging strung out all around a cockpit some of it under extreme loads. Note the two helms, two steering stations. Sometimes the single helmsman wants to be on the upwind side of the boat, sometimes on the downwind. And while you’d never have two helmsman steering at once, the winch nacelle is easily accessible from either side. This is the safest most compact and user-friendly control center I’ve ever seen in a boat. So when lollygagging around at speeds in the upper teens of the low twenties one guy can fly this bird Of course when racing there’d be a sailor on the helm and on the control center, on the winches, too. Maybe even two sailors. Not yet in place on the bridge deck is a all-around bar and galley and seating for eight guests. So the Eagle swims, late February 2019. And it looks to me like she’s streaking right along in a flat sea. What do you think maybe eight knots of wind and twelve knots of boat speed? That hybrid wing is up there sucking every last ounce of energy out of that ghosting air. She’s on the starboard tack so we’re looking at the downwind side and note the difference in the wakes between the two different hulls. The downwind hull is showing somewhat more disturbance of the water than the upwind hull, although both of them appear to have

very clean heels with practically zero disturbance at the bows, no bone in her teeth. The title of this view is “Coming At You”. Think of seeing this at night Note the carapace, it’s slightly dished in the middle so that when the hybrid wing swings it sweeps the carapace with that slight arc to really form of sealed end plate for the wing. And note the pod in the tunnel between the hulls It’s probably the most massive single member in the boat. It supports the bridge deck but it also handles the cantilever stresses of the bowsprit which we can’t quite see sticking out toward us to mount the stays that fly the jibs. And see the crew? That looks like Tommy on the helm far left and Randy in the white t-shirt at the winch nacelle. A very different boat. Hey, now she’s showing off her figure. And at last we can really see the bowsprit and the two stays headed up for the top of the wing. The inner jib stay is flying the jib and at the outer end of the bowsprit is the stay for the big light airs drifter. And notice the foot of the jib, there’s a diagonal batten to get the foot down as low as possible to grasp every ounce of air trying to escape underneath the sail. And the same thing for the hybrid wing. The rigid portion of the wing is down very close to the carapace and the soft portion of the wing has another diagonal batten to sort of sweep the carapace. Not much air escaping there. Of course, the boat is very lightly loaded but notice how this downwind hull doesn’t even touch the water until what, three or four feet back from the bow. I think we’re looking at the future. Hey there’s Tommy up on top of the carapace. Note that all the sail handling happens away from the people on the bridge deck. And here is Eagle’s patriarch. Congratulations Tommy Gonzales Here she is on her first swim off St Thomas, US Virgin Islands. Tommy shipped her down here for her very first trials And look at that rig. The dark areas are both soft sails and with them lowered the rigid portion of the wing, the transparent portion, can rotate 360 degrees inside of the rigging that holds it up. We’re looking at the first practical wing sail rig and I think we’re going to see a lot more of them Because I think it’s a significant waypoint in nautical history. There’s no doubt in my mind that one of these days humankind is going to need this technology. That is, we’re gonna have to use the power of the wind and the Sun for cross water transportation. It’s inevitable. I may not live to see it but I’m thinking that nautical historians in the future are going to look back on this combination, that is this extremely advanced multihull combined with the hybrid wing combined with hydro foils particularly the T foils containing articulating control surfaces that will be eventually controlled by a computer. We’ll have automatic flight control in a fully foiling vessel as combined with the hybrid wing. And right there is a combination that I think of as having historic significance. It’s going to be around for a long time Hey now how about some credit where it’s due Here’s a heartfelt thanks to the great British marine photographer Richard Langdon for providing many of these visuals the first light airs trials of Eagle. I expect that by the time he catches her again she’ll be flying high on her C foils in a Caribbean trade winds seaway. For the full backstory on the Eagle you might enjoy our half-hour podcast about the boat. It’s posted with our other podcasts and our other videos at that’s We hope you enjoy them all. Fair winds