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.
Stealth rudder stock and T Foils on a home made gantry
Home made under tramp snuffer/dolphin striker and centre mainsheet fixing point
Home made tramp and a new Harken track and sundries will be fixed soon pending the postal strikes here in the UK.
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. <img src="<>/cool.gif" alt="cool" title="cool" height="15" width="15" />
Very slick very cool. Cant wait to see some OTW action photos.
I can only say congratulations on pushing the project through, AND keeping it under the radar! <img src="<>/grin.gif" alt="grin" title="grin" height="15" width="15" />
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?
OTW reports eagerly awaited!
What is the story about the name btw?
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 <img src="<>/smile.gif" alt="smile" title="smile" height="15" width="15" />
Nice!
Sharp snuffer opening though...?
Wayne,
Could you give more info on the layup? What type cloth/foam/resin/gel coat did you use? Did you vacuum bag? Thanks.
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...
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 ).
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.
good luck with the new boat.
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 <img src="<>/smile.gif" alt="smile" title="smile" height="15" width="15" />
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...
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.
It is all good. I bet there are others than Wayne waiting for this creation to get on the water (I know I am).
Excellent photo find Pepin.
Here's a couple more photo's of the Bitza, bow and 6 degree centre board angle and the hull section at the stern
The bottom gantry doesnt look as strong as the top one, not that I know anything about building though.
Spot the difference in the
bow on
shot to a normal hull
The Stealth rudder stocks have no
beaching
safety mechanism so the lower bracket has a
weak point
which I hope will break first should I clout something in the water at speed. The same section is threaded to allow adjustment of the foil. Any vertical stresses are taken by the upper more beefed up pintle.
No dings or scratches from hitting rescue boats hidden behind Committee boats?
Ah no wrong reply but I bet after about the first 5 minutes of my sailing, you won't be far wrong. <img src="<>/laugh.gif" alt="laugh" title="laugh" height="15" width="15" />
bow on
shot to a normal hull
Split forestay attachment way back on the hull to give as much space as possible to the spi so it can fly to either side from its under tramp position. Do I win?
Then it's got to be those special knots you use, you know the ones, only come apart when you least want them to. I still remember Grafham 2006, first race just started and within 30secs a big splash.....good knot Wayne. I guess you don't use them on your traps anymore! chuckle, chuckle <img src="<>/grin.gif" alt="grin" title="grin" height="15" width="15" />
I think you're really close Pepin but I think it may have something to do more with the spi pole?
No, just to do with the hull, yes the splash was embarrasing to say the least <img src="<>/blush.gif" alt="blush" title="blush" height="15" width="15" /> and I couldn't blame anybody else. Since learnt to read manufacturers instructions better.
Nice job Wayne!
Noone seems to have commented on the daggerboards being canted the 'wrong' way to perceived wisdom?
I think you're onto something there though as there will undoubtedly be some lift generated with that setup that should help in reducing drag.......
Have you done any theoretical calcs at a range of speeds?
Noone seems to have commented on the daggerboards being canted the 'wrong' way to perceived wisdom?
I think you're onto something there though as there will undoubtedly be some lift generated with that setup that should help in reducing drag.......
Have you done any theoretical calcs at a range of speeds?
Eh????
John, I see them canted in (so tips are closer than the top); Standard in the A class fleet.
Wayne, are they
true
in the hulls; some A classes have them slightly toe in to create even more lift.