I have not seen BC1 and BC2 terms used before. Are these the Bob About 1 and 2? If not, what are they?
ffastfrank please think about Brent’s “nome de plume”
After all its all in a name
Brent - I’ve always been a fan of the slim IOM’s and Marblehead designs, something about how they move through the water. So that said - with total due respect to all the great Footy designers out there - I am completely impressed by your svelte & slim designs. Your double enders look very low drag & I look forward to hearing more on how they sail. Any chance of posting some video? (Also your Fathead rigs are also very sweet looking.)
The thin hulls sail very well. The best way to express my feeling about them is that they sail like a larger boat. No big surprises, reliable tacks and a decent turn of speed. Watching one accelerate out of a tack is still enjoyable enough to get me to go down to the local pond by myself just to sail for pleasure.
Running in a decent wind will still result in the bow going under but the interesting thing is the boat continues to steer reliably and hold reasonable speed. It can broach in a hard enough puff if I don’t head up and/or sheet in in time but so will my larger boat.
I don’t own a video camera so I can’t promise much there. You can see more stills here: http://www.sundaysloopers.com/photogallery/v/2008-08-03/?g2_page=3
Pages 3, 4 & 5 all have shots of the boats.
I’d like to hear more about that rig you’re using. Looks good.
The history of the other tradition of thin Footys - Moonshadow, Vootrekker, Thintrekker has been more patchy. I must state at this point that Thintrekker is a Gary Sanderson design based on my Voortrekker. He’s not responsible for my mistakes and vice versa (all in the best and most friendly sense).
All these boats have become progressively lighter and narrower. At 335 g Moonshadow is reasonably easy to sail, Voortrekker implementations are generally little if any lighter, but 10 mm narrower. They show flshes of dazzling speed but it is difficult to achieve consistency. It may well be that Brent’s narroe steamrollers are the way to go. For the immediate future, Easter Saturfay has the same 90 mm beam as Moonshadow (unbelievabky narrow just a year ago)
In response to the kind comments and inquiries about the fathead swing rig I’m posting a decent picture of the rig I’m using. I also posted this information in the Swing Rig thread.
Mast and fixed boom are 4mm, gaff and jib club are 3mm. Obviously the gaff can be eliminated completely if you go with a standard main as opposed to the fathead which I’m quickly becoming very attached to. You could keep it if you wanted and have it do duty as a mast crane.
The Z bend element at the bottom is a key to the success of this rig as it quickly allows you to relocate the sail plan to adjust for a misplaced mast step or changing wind condtions for those of you who insist on using wide hulls.
Angus, your experience with these ultra-light Footies, those flashes of breathtaking acceleration mirror my experiments with 8-12 lb and 8 lb M Class boats in the early '90’s. I too was seduced into continuing by those glimpses of potential, but they were too fleeting, a culmination of several factors of wind speed, water conditions, and who knows what else, all aligning at the same point in time. But man, when the boat would hit it just right it would get exciting!
Most of those “Oh-my-God!” moments would happen on off-wind legs, particularly reaching ones. Occasionally it would happen on a beat as well. All of a sudden my boat would be scooting by the others as if they were standing still. They were still among the fastest boats downwind in their time. But, in the game we play the off-wind legs are hardest to make any gains on your opponents as you all have pretty much the same wind coming from the same direction. It is upwind, when boats have to fetch the course mark by tacking up the course that gains or losses occur most of the time. The first windward leg is often the most important. Getting to the first mark first (or at least in the first group) you are in a controlling position over the boats behind. By having a boat that is fast downwind but ceding some upwind performance (light weight = less inertia in tacking and less righting moment) you put yourself into a position playing catch-up. But to win the heat you not only have to catch the boats ahead of you, you have to put enough distance between yourself and them to make sure they don’t just pass you when you turn back upwind.
What I realized from these experiments with light weight M’s was that highly specialized boats may sometimes show the way but often are average performers until the rare occasion when they get that magical combination of inputs that make them dazzle. I guess that I got a great deal of satisfaction from these occasional triumphs. I saw them as a vindication of my design originality. But in fact, it is the boat that performs adequately in a broad range of conditions that wins consistently, provided it has a good driver on the sticks.
My guess is that Brent is following a promising branch of the Footy tree. I wish him luck. By the way Brent, nice swing rig. My only suggestion is to angle the jib spar up 10 to 12 degrees. The fastest way to stop a boat with a swing rig is to roll to windward on a run (it happens more often than you would think when using a “balanced rig”) and have the jib dig into the water. A sudden stop like that can snap things loose inside, I’ve seen it tear up portions of a deck once.
Now Footies are small and don’t have the mass and inertia of the larger classes that allow swing rigs. But we do keep building them lighter and lighter and there is no accumulation of data that shows where the tipping point between too delicate and too robust is. I think it is better to avoid known catastrophic situations than to tempt fate too much by not considering them when designing a rig.
I think you’ve captured my limited Footy sailing experience pretty succinctly. My early lightweight designs were regularly beaten by boats that were of much heavier build in the hull, radio and or rig, with resultant lower ballast to weight ratios. Some of these boats also had less sail area and lower aspect rigs. What they did have going for them was that they were well balanced, had enough inertia to never miss a tack and the rigs were properly adjusted for the prevailing conditions. My lightweight, often overcanvassed boat would make great gains downwind or reaching and do at least as well as the rest of the fleet upwind unless conditions required several tacks. Inevitably I’d miss one or more and watch the fleet pull away while I sat in irons. I did eventually win one local regatta with one of these boats, by 1 or 2 points, due primarily to a new swing rig I had tried.
Since moving to the Steamroller concept (Thanks Angus, I was considering naming one of the boats after my lovely wife but now she seems less enthused about the idea. ;)) what I notice is that the boats perform very consistently in a variety of conditions. In heavy air I’m not worrying about missing a tack because of a lack of momentum. In light air I have been saved a few times by having enough way to pinch up around the windward mark, something my light boat would never do.
I had the BC1 out Monday testing the new legal “B” swing rig and was fascinated at how quickly it would go from tack to tack, literally in a second or so. I could snap the stick over and release it and the boat was accelerating away on the new heading. None of my early designs (nor unfortunately my current experimental hull) can do this. Knowing the boat will do it’s job frees me up to consider other aspects of the race.
I have this perception while racing a Footy that time also scales down during a race. At least here in Central Florida most of the races I have participated in see several fairly significant (in Footy terms) changes in wind and wave speed and direction. This happens even though the race may last only 4-5 minutes. What I take away from this is that to win consistently the boat has to perform well throughout the envelope. For me this translates into the largest sensible rig I can carry. If my design is stiff it will remain sufficiently upright to perform in the puffs. When the wind lulls I can often get the light air sooner or keep it longer than the other guy if my rig has a higher aspect ratio than his.
None of this may agree with time tested theory but on the ground (so to speak) it’s working so far.
Thanks too for the suggestions on improving the swing rig. I’ve already had the jib dig in on several occasions. These foam hulls seem very robust so no harm so far. On the other hand the idea while racing is to go fast and a jib in the water is no way to do that. I’ll look at ways of angling the spar up as you suggest.
Moving the spar up at an angle has me thinking again of an idea I had abandoned some time ago. Perhaps you are thinking along similar lines with Brujo. As I see it there are least two possible approaches to the issue of submarining. I can try to create forces to resist it or I can go with it and try to design a foredeck that will move at decent speeds and allow directional control while submerged (my humble apologies to any Luddites among us). The angled jib spar leaves some unused space above a traditional deck that might be creatively employed to one of these ends.
I’ve been searching for where I read this without success, so you’ll have to take it on faith that at some point Olin Stephens said “Always build the biggest boat the rules allow.”
From what i have heard, Olin would say that.
I don’t know whether he meant it in reference to weight, but i have been thinking greatly about the footy design concept. The “featherlight” footy has merit, but without revealing some cards that i am not sure i want to reveal yet, i think it may be time to revisit (to an extent) the old “sled-inspired”) concept…*
*Angus, don’t consider this a victory yet… we still, i believe have some differing concepts about how a “thin footy” should go…:rolleyes::devil3:
… and like many other sayings of the great, it needs to be examined with some caution. If you interpret it as meaning “go for length at any price” or “hooray for the steamrollers” or any such noises, it does not stand up to much scrutiny among S&S products – let alone anyone else’s. I’m not sure about what happened under the CCA rule, but on my side of the pond (or in the middle), Dorade, Hestia, Roundabout/Clarionet/Rainbow and the She 31 all represented a fair drop in displacement compared with the norm at the time. The early to mid-period S&S 1-tonners like Story Petrel/Swan 37 were shorter, lighter and generally faster than their Carter jumbo equivalents (Wai-Aniwa). When S&S attempted to follow Carter with boats like Columbine and America Jane IV (I think IV – or that may have been the Scott Kaufman one), the results were catastrophic. And then along came Ganbare and Golden Apple (4 feet shorter, 7,000 lb lighter) and ATE THEM ALL UP.
Whatever Stephens meant (unless it was a joke) he was not advertising pure bulk. However, there are certain conclusions that we can draw from looking at this lot. I sailed on quite a lot of S&S boats of the generation between Hestia (Fastnet overall winner 1963) and, say, the Swan 37 (c. 1974). They did, indeed possess the special virtue of being good all round the clock. Obviously they had some positive strong points, put they had no weak ones. A remark attributed to Rod Stephens –“Only level with you at the leeward mark, then up to weather a minute a mile faster” – sums it up, although one does have to assume a running start!
Remember that a lot of alleged ‘lightweight flyers’ were not actually all that light. I don’t have the figures immediately to hand, but such famous Finot designs as Révolution and Écume de Mer were actually quite heavy compared with what was possible: I remember an incredible thing called Subversion designed by Joubert, which was basically a 40’ Flying Dutchman and must have weighed less than half as much as Révolution. The only time Subversion did any good was when she won the Channel Race. She arrived at the Le Havre Light Vessel about last, eased her sheets and climbed onto a wave. When she got to the Nab Tower 80 miles away, she got off it, came on the wind for 100 metres and took the gun.
I think that the important thing is that the power/weight ratio must be adequate ROUND THE CLOCK. This means weight that is light enough to slide down hill, but enough sail carrying power to generate some thrutch going up hill as well. I consider Moonshadow to be a fairly successful experiment – but you must remember that her ballast ratio is higher than any of Brent’s boats. This is the result of a very detailed build programme by Brett McCormack. Voortrekker looses out on ballast ratio and so far is less satisfactory.
My current belief is that the right displacement for most conditions is probably somewhere between Moonshadow and Duck. On beam, I don’t know. I may not have been reading the threads attentively, but I don’t think I’ve seen a picture of Brent’s BC3 out of the water. My attempts to draw something that heavy on that beam have yet to produce anything I like, either on a ‘looks right’ basis or as a set of numbers.
This is actually the first request I’ve had for pictures of BC3. One guy who has seen it did express the hope that this was not the future of the Footy. Before you laugh too much keep in mind that I’m trying to see how thin is too thin. I realized after building this one that I could go thinner yet by placing the batteries side by side in a 1x4 configuration. It remains to be seen whether building a thinner hull will be worth it. So far I think the BC2 may be the fastest boat in my stable. The BC1 only marginally (this is as yet unproven) slower has a respecatble turn of speed while maintaining lines that look like a real sailboat, especially with the new simulated planked deck.
I’m not sure I’d spend much time considering BC3 yet. It may just be a keel placement issue but I’m not all that pleased with the performance so far. I’ll sail her more today and if she doesn’t tack more reliably the keel (but not the ballast) will be moved forward. I know I’m pushing the limit here for the distance between the keel and the rudder. Stalling is almost certainly the problem getting her to come about. The boat steers smoothly on all points but tacking is unreliable at best. The other 2 designs both tack well, even if you are sloppy and just slam the stick right over.
I haven’t managed to get her in the water against another boat yet either but my perception is that she is slower than BC2. This is stictly an observation since I have no training to do with boats at all but the wake generated and the wave down the side of the hull on BC3 (2"/50mm beam) also don’t look as clean as that on the slightly wider BC2 (2.75"/70mm beam) hull. The wave form on the lee side of the hull almost looks flat at the bottom.
So here is the picture for what it is worth. The little blue tick marks at bow and stern are the water line. I hoped by keeping the displacement aft I could keep the bow up through a combination of longer lever arm (pitch center further aft) and sufficient bow freeboard. That part of the experiment seems to be working out okay.
Very interesting boat Brent… what happens when it heels over to port? Does the sail arm just go for a swim? How does that affect the handling?
Angus; in respect to what you have said, I am not proposing a “lead-sled”, but in a recent conversation with a pilot friend, the topic came up “air-speed is king” that and the ability to keep airspeed on throughout all flight attitudes… I think in many ways footy sailing is similar, we do not have to control altitude and sink-rate, but we do have to control our heading toward the wind, and our ability to carry speed through maneuvers; a feat that in my experience, the “bantam-weight” footy does not do as well as it might… this is due to several factors that seem to be simply the nature of footys, one is how short their waterline length is, compared to their necessary draft – there’s a lot of drag there! Also the way they handle a sea-state is, I believe, a major count against their potential… So too the “bow-down” attitude when off the wind… Some of these can, I think, be remedied… in part with a boat that has slightly more capacity to hold onto its kinetic energy, in part with some different shapes, styles, and (possibly) setups than have been tested as of yet… either way… we shall see!
The sail servo arm is nearly fore and aft when the sail is sheeted in for this and one other very good reason. The only time it is completely athwartships is on a dead run when the angle of heel is not that great. This hull also has a fair amount of freeboard which helps. I haven’t actually seen it hit the water yet.
After sailing for about an hour today I’m still undecided on whether or not to move the keel forward. I suspect in the end I will but I do like the fact that it takes a fair amount of wind to push that skinny bow under as currently set up. It seemed to tack more reliably today when I would sheet out a click or two before easing the rudder over.
By the way how much of Stiletto’s 14-15oz is in the bulb? Any plans to add the extra 1.4" that is available to her waterline? She appears to have the figure for it.
Stiletto has close to 5 oz’s stuck to the bottom of her fin, and actually its much more stable than I ever imagined, however, I don’t believe that there is much of a re-design in store for her (much as she could use it!). Instead I am hoping to try a new shape with a lightly more organic form, which will definitely make as much use of all the waterline it possibly can!
takes deep breath Anyhow… that is the long answer to a short question!
Sounds like you have found a pretty good set-up servo wise; I’m interested because I managed to crack a servo housing during the Region 1 regatta this spring, and getting to the bloody thing proved to be too much of a chore to even think about affecting repairs.
I’ve been thinking about moving my keel aft as well, I’d be interested to hear more about how you feel it affects handling – other than changing how the helm responds, are there any other side-effects? Keeping that bow up is a life-saver… especially with a narrow boat – Stiletto gets pretty squirrely downwind as her stern (and therefore much of her rather stubby rudder) comes up for a visit to the land of air…
BC2, which I suspect is the fastest Footy I’ve built to date has her keel centerline 7.875"/197mm from the bow. Her waterline length is 13.4"/340mm.
I haven’t noticed any negative aspects to this location so far. Steering is very smooth and predictable even downwind with the bow submerged. (Have I mentioned my tendency to overcanvas?) She will eventually broach but by then so do the other boats I’ve sailed or sailed against. The aft keel placement means the rig CE is also necesarily located farther aft and this seems to help in keeping a fine bow up.
Your rig photo from an ealier post showed a mast step wire with a bend to the rear in it - a bit like a McCormack rig Z Piece but shorter and in the opposite direction.
Now I’ve seen where your fin is positioned tells me that is why your Z Piece is bent rearward - its to get the sail centre of area in the correct position relative to the underwater areas of hull, fin and rudder.
If your finger is the same size as mine it looks as if you could afford to move the fin forward by about 20 mm and then use a mast with no Z piece bend.
I suspect that if you moved it even further forward then you could have some forward Z piece bend and gain a bit of McCormack wind dumping twist at the same time.
Moving the fin forward should also give you a bit more response to rudder movement as it will give a bigger turning lever - notice how many designs have a transom mounted rudder to achieve to same effect.
VERY INTERESTING, these thin boats.
I must get Sloice on the water - as severial “friends” have been pointing out for a while
She is a rousing 14.5mm wide, and I have to deep-freeze the AA cells to get them in place.
This is an early photo before detail like floors were added - I now have the snag that I have no legal radio rx that will fit in the hull, but can give her test glides with my Falcon micro rx, or use i/r, so long as we sail in the dark
I will likely move the keel forward about 20mm as you suggest. I just want to sail her a bit more as is, in a variety of conditions, to be better able to evaluate the effect of the change on the boat’s ability to keep her bow up.
BC2 has a rudder CL to keel CL dimension of 4.5"/114mm and steers very well on all points. This boat measures only 3.2"/81mm rudder CL to keel CL so I’m hoping the 20mm change will yield the desired results.
By all means get Sloice in the water. As the ski jumpers say “Fat don’t fly!”.
I will eventually do a boat in the 25mm beam range just to say I did but I’m not expecting much performance from it. Then again I’ve been wrong before… Keep me posted on your project.
Anybody else have any slim Footy photos to share?