Wayne Marlow has been very busy recently building an F16. The out come is very impressive and innovative. The building thread is getting quite long and really wouldn't do this home build justice. And as some of my photo's have disappeared off the F16 Forum CS users will be the first to view the new Bitza F16, although it's not quite 100% complete just a few more hours is required to get her on the water.
Ah so the paparatzi have outed my little project. I had hoped to have it Datchet this weekend and even bought the trailer home to take it to the pond for its first sail but alas I'm still a few hours away.
For a bit more detail, its a all carbon foam carbon/kevlar pretty standard design, perhaps a little dated in its amount of rocker but as it was started about 3 1/2 years ago, that was the currency of the time and what the A class design that we had obtained the moulds for, had. Actually I'm quite happy to have the extra rocker in at my stage of sailing as I feel it makes a more forgiving and manouverable boat than some of the more flatter designs of the recent A class's. Hulls are on par at about 24 kgs.
Why the central beam, the design I wanted always was for the central beam to take all the loadings including the forestay, but due to not knowing enough about how to transfer loadings to carbon fibre layup I wimped out. The Y beam that we are now seeing in the AC was in my mind some years ago ( and yes it had been tried long before that )when I first started to build the hulls and by consequence I have relatively smaller diameter main beams. Mind you its as stiff as my Stealth so still happy. The central beam also allows the snuffer pole to go lower down and become self supporting which means I hope I have cut down on nearly all the aerodynamic windage associated with the snuffer and spinny pole. What you see in the photo is the complete boat. I do hate to see some of the F18's and F16's that have a weavers loom on the front.
The gantry at the back is probably OTT and in leverage terms pretty miniscule but as a consequence of wanting to move the rear beam and sail plan back in the hulls, the size of the F16 sail was starting to hang right past the rear beam meaning much higher upward loadings on the beam from the main sheet which would have been much further foward on the boom than I was comfortable with. It simply meant upping everything at the back of the boat in size to cope and that would have put a lot of weight just where I didn't want it. The downside was it played havoc with the steering bars, they were as short as a porn stars d*** and thats really no use in sailing terms. I was also toying with the idea of gantries as there is some advantage to have the rudders further back particularly as I angled the daggerboards at the maximum 6 degrees allowed, I hope the lift from the boards together with the T foils will allow the rear of the boat to raise rather than sit down at speed as the amount of rocker would dictate. The hull length foward of the front beam and the T foils should stabilize this with the spinny up ( well in theory )
Lots of other niceties in the build and I hope it will sail as planned. But for all those budding homebuilders out there, it seems to take forever when you can only spend a few hours each week but it is very satisfying when it all come together.
I can only say congratulations on pushing the project through, AND keeping it under the radar!
It looks very good, and I hope it is your perfect boat.
Are the gantries included in total length, or are they "free" when measured? Did you do the foils yourself? How about rig, what are you putting on top of your new eyestone? Wingmast, teardrop shape? Homemade sails or pro sails?
As I see it if Waynes Bitza was to be measured by an approved measurer then the overall length of the hull would be just that. The gantries are not a part of the main hull and are just a pivoting mechanisms for the rudders. Otherwise, if this is not the case then every F16 I know of wouldn't measure as the more usual gudgeon, pintles brought off the shelf and protrude 35-40mm ( 1.32-1.5") behind the transom. Add this to hulls which are already 4995-5005mm long and we are all in the s**t If anybody has a different view then you'll have to be able to explain to me in detail at what stage does a normal gudgeon become a gantry, is gantry the right term? you could call them extended gudgeons or gudgeons on viagra
Wayne, I'm doing safety at the club all day Saturday. Let me know if you bring your Bitza, I'll bring a camera...
For the non-native english speakers like me, I had to search the meaning of "bitza": it's an alteration of "bits of". So I guess the name is a reference to the fact that it is made of bitza Stealth, bitza A cat and bitza home made...
Re: BITZA F16
[Re: pepin]
#191550 09/22/0903:44 AM09/22/0903:44 AM
For the non-native english speakers like me, I had to search the meaning of "bitza": it's an alteration of "bits of". So I guess the name is a reference to the fact that it is made of bitza Stealth, bitza A cat and bitza home made...
Spot on with the name, it is a iteration of bits of other boats, the T foils I do think work ( but not quite in the way we think ) the A class hulls work very effectively and this particular design had been set up for heavy weight fat boys like me and as a plus had more volume foward of the beam than any other design I had seen, and there are loads of other " bitsa other boats ". In fact this is Bitsa3 as my other two boats were build ups from what ever I could lay my hands on ( see I'm really a recycler and very PC ).
Did you do the foils yourself? How about rig, what are you putting on top of your new eyestone? Wingmast, teardrop shape? Homemade sails or pro sails?
At the moment I have an A class wing mast and sail which I want to try, just to see what these really high aspect sails are really like. Looking at the SCHRS calculator, with the reduced length, reduced width ( 2400mm as I feel my Stealth is over width ie the righting moment overcomes the bouyancy of the hull creating unwanted drag )and smaller sail area, the handicap is acutally slightly lower than an optimised F16.
Foils are Stealth, there is no point in reinventing a good wheel.
Are the rudders not to far from the stern? Its he the first time I see this.
Well, you should look at Moth or skiffs to see how far they do hang their rudders, Wayne's is fairly sedate compared to those
Note that the reasons for those long gantry are different: The Moth want the rudder way way back because it will reduce the size of the T-foil as there will be less weight to lift due to the increased lever effect. Or something.
On the skiffs it is as far back as possible so it stays in the water when they fly their ridiculous spinnakers which are pulling the whole boat out of the water (kidding, it's because there is a better undisturbed flow further back, the smaller the boat, the longer the gantry. 12' skiffs are insane.).
As for Bitza there is not enough space between the rear beam and the transom to fit the tiller bars.
It's all perfectly legal, the rules only limit the hull length, and as long as they are not buoyant you can make the rudder gantry as long as you want...
Last edited by pepin; 09/22/0905:39 AM.
Re: BITZA F16
[Re: Gilo]
#191568 09/22/0906:55 AM09/22/0906:55 AM
Gill The new Loday/White F18 Shockwave has similar length gantry as the Bitza. You might be able to make them out in the attached photo, but I think they will definitely work for this F16 as the distance from the transom to the rear beam is tiny compared to a Blade.
