If anyone’s interested, there are some pictures of my new Akela design ACTUALLY SAILING IN REAL WATER at http://s111.photobucket.com/albums/n138/angusrichardson/akela/
Congrats on what looks like a decent trial sail Angus… veeeeery interestink. Slim little bugger innit!
very nice boat angus! looks dangerous! hmmm… gonna have to get a stiletto to race it sometime!:rolleyes:
Footy’s can have 2 masts? I thought I read that it was limited to single masts.
Congrats on what looks like a decent trial sail Angus… veeeeery interestink.
It is certainly slim - only 84mm across the deck.
You have to love that transom…
HSOK, the technical committee ruled some time ago that since a mast is defined by the ERS as a spar, and multiple spars are clearly permitted by the rule, then multiple masts are permitted. Technically, one is a mast and the others are vertical spars.
Congratulations, Angus! A pretty boat, indeed…can’t wait to see it in a bit more wind…and sailing against your Kittiwake.
Heh, tricky. That’s actually really cool since I wanted to do my Footy with 2 masts, but was going to leave it at 1 to keep it legit.
You have a very interesting concept with the 2 masts. This is something you never see anymore. It is probably practical only on a very small boat, where the stresses are minimal. I can see that it might be better than a single cat rig, because it gives more sail area, with relatively high aspect ratio, without adding height (and heeling moment). I can also see that it might be bettter than just going to a sloop rig, since the sails are further apart. Has your testing indicated a real advantage over a conventional sloop rig? Or the McCormack rig? Does it go to windward as well as other rigs?
The primary figure of merit for a sail plan (in an unlimited class) is forward thrust vs heeling moment, and you may have hit upon an optimal solution.
At first glance, it would appear that you would lose half your sail plan going dead downwind, but you have probably found solutions for that by now, either by tacking downwind, or finding a way to wing the 2 sails. But maybe it is better to lose half your thrust going dead downwind in a strong wind, to avoid submarining.
You are to be congratulated on coming up with this unique scheme. Of course, the Reynolds number of Footy sails is far below anything else that was ever contemplated by anybody, so the aerodynamics of the sails may be quite different, and it is only by playing around with strange alternatives that things can really be optimized.
Thank you for the complements, few of which are deserved! The rig derives immediately from the 21 ft. Poacher 6.4 which my brother and I designed in tthe late 1970s, which was, in turn, cribbed off the FReedom Rig pioneered by Gary Hoyt with the 40’ Freedom 40. Obviously there have been considerable changes along he weay, but it would be quite wrong to deny the development path.
Full-size Poachers are very fast to windward if you foot rather than point - and devastating on a reach. Unfortunately, masterials sourcing means that Akela’s masts are too stiff. When I can get the right tube I am going for taller masts with a stepped taper from 4mm to 1.5 mm o/d.
A little attention to the complex (in terms of geometry - the actul physical manifestation is quite simple) sheeting system provides both automatic goosewinging and the final differential ‘bite’ as the two sheets are hailed home on the wind. The windward trim bit does not work ideally yet because the geometry of the sails/wishbones was not properly understood when that set of sails was made, but on paper it should.
Akela looks really good in the photos... You mention going to a taper mast and give your dimensions... I am not near the workshop right now but will measure the ones I have and see how close we can come... I am using a taper mast on my Kittiwake... The masts I use are left from a small kite building company we had... They are made by a company called Avia Sport for the kite trade... Wrapped carbon fiber, much lighter than the pultruded tubes... I will check my masts when I get to the shop and let you know their sizes... Good luck with the new experiment...
Have you done any speed comparisons between your Akela and other Footy designs? Making valid comparisons could get interesting in an open class when the boats may have different amounts of sail and ballast.
In a light wind, the boat with more sail wil probably be faster, but in a bigger wind, the faster boat might spend all its time on its side or submarined.
One possibility of a valid comparison would be to race against a standard design, like the Bob-About. But keep the same sail area and mast height and keel weight for both boats. This test would demonstrate a superior hull design or sail plan.
In your last paragraph, exactly what are you proposing standardising and how? This problem is fraught with peril!
Angus… may I ask what was the final on the water weight/displacement?
444 g with competition batteries batteries and a 212g bulb. Bulb weight increased slightly, but not proportionatelly to help drive esxcess parasitic weight.
with regard to my question about comparing the speed of Footy designs:
As you stated, it is indeed fraught with peril. That is why my suggestion was a little vague. We can take joy in the wildly different designs of our boats, but human competitiveness eventually demands an answer to which is fastest? In an open class like the Footy, there may be no firm answer.
However, the internet speed competition is a good step in that direction.
You mentioned the weight of your boat, which is probably the lightest that has been mentioned in this forum, so it is probably fast by any method of comparison.
Narrow beram and light displacement should give a god turn of speed, so long as there is sufficient operational stability. It is also beginning to look as if the UHPB hull form may have merits. Trials withe Akela and pictures of the Australian 507 (my example is in transit) are highly encouraging. I am beginning to be optimistic that these hulls, which have quite a lot in common with your Pepsi Torpedo, may represent a genuine advance.
interesting Angus. Akela weighs almost exactly what my Stiletto weighs… great minds?:rolleyes::zbeer: lol.:sly: