I am considering building this. It can be built very inexpensively out of lumber yard materials. I think the design would be fast. The down side being the for stay strength. If it failed it would it would be catasrophic. The upside is the sail has a natural tendency to center itself, lending to the close haul used on a land yacht. I don't think it would take much effort to sheet in. I am a cabinet builder so I want to use wood to build my next yacht. Besides the strength of wood and ease of use, I just want to beat my buddy in his iron yacht. I am looking for opinions and comments.
Wow love the ideas that come forward here I have seen this type of rig on a water
yacht If I am not mistaken I think its called a Luna rig
I will be interested to see the comments as to its suitability for landyachts as to
centre of effort, resistance, etc etc by people on this forum who know these things
Cheers Hiko
Here are a few pics of my study model without wheels
. The CE is a little foward, but you get the idea.
I think it would be interesting to try, if only as a learning exercise. The "old rules" of coinciding centre of effort, centre of lateral resistance and centre of gravity would be difficult to achieve, but perhaps a new take on this may succeed?
Forestay strength, I see no reason why this would have any higher loading than any other soft sail, and perhaps less as there is no leach to control, although a bit of roach may help the twist! I used (as per the rules of the British Association) a 5mm forestay for a Class 3 as in my avatar. 7.35sq m and around the 70mph recorded.
Is there a reason why you want to experiment with this design? You could do the same thing except move the mast forward and use a conventional landsailing rig, using the same materials. I believe the mass would be lower too, as you could remove the structure required for your rear stay wires.
On the other hand I think your design looks great. Easy sail design/platform to produce and use, very pleasing design to my eye I like unorthodox!
LOVE IT, 
LOVE IT, LOVE IT, LOVE IT,
Have a read of this en.wikipedia.org/wiki/Mast_aft_rig
with landyachts the biggest restriction on speed is aerodynamic drag, the mast system you have might cause lots of aero drag, but that can be reduced with some trickery 
Gidday Blew, I also like it, a lot...do you have any measurements available?
Have to be a "Classic Class" Woodn-it-b-better [great name]
Yerh, also wearing me sox, no wonder i cant find them !!
My thoughts are that in light winds this will probably be okay, provided you get COE and COG near balanced. In heavier breezes I think the sag in the forestay would give more sail twist than a conventional rig and cause a lot of drag, so would probably have to come down in sail size sooner. I am no expert but just some food for thought.
How about this taking the design just a little further... "A" frame mast, the mast/s could be made as an aerofoil shape reducing drag and increasing the sail area as wing sails are very efficent.
How about removing sail leave aerofoil masts as wings keep forestay and go with that
Hey guys,
Love the ideas of the airfiols as a mast and as the stand alone power. Kind of defeats the simplicity angle but it is definitely interesting. As for dimensions the wheelbase is about 6' to 6 1/2' width and about 8' fore to aft. It would still be a mini of sorts. The mast being 15'- 16' long. It could be airfoi shaped fairly easily to help with the drag issue. The sail would end up in the 45-50 sq. ft. range. The size is mostly derived from where I have to sail it, which is small school parking lots. In those lots we cannot achieve full speed anyway. It is fun and makes for some close racing. It is kind of like playing chicken. You go as fast as you can for as ong as you can and hope you can make the turn with out crashing. If you look at my photos you will see one pic where I didn't make a turn I my buddies yacht and ended in a snow pile at about 25 M.P.H.. Thanks for the input I will stay in touch wth my development.
I like unorthodox!
I like unorthodox!
Lighter still to use only a forestay and support the mast like any torque tube yacht, or get a bit trickier still and use a luff spar on the leading edge, could be a baby wing shape then!
Im thinking you could build it and trial it in a single weekend for only a dozen beers.
please do it. having a "regular" landyacht to test against will be great
I think the one weekend and and a dozen beers just sold me on going foward with the experiment. Thanks for the encouragement.
sorry, did not realize you needed encouragement to drink. hope i haven't let you down in the past and will be more supportive in the future.javascript:insertsmilie('[}:)]')javascript:insertsmilie('
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The luff is the front edge of the sail right? 
Yes luff is the leading edge of the sail, so a "luff spar" is like a baby mast hanging on the front, normally very aerofoiled and free to rotate in line with the sail. Probably such an old idea that even landyacht won't have seen them!
Featured very strongly in a lot of the aerodynamics "bibles" as a good idea.
I think in this case it could link with the mast and provide some extra support, as otherwise all the mast has to cope with is a compression load.
Yes Paul but of course a luff spar was never used on a sail hanging from the BACK of a mast. They were on jibs and mast aft rigs only!
the 2 Ive seen on water didnt perform well . the owners had got fixated on them being really good . the extra side and back stays and stiffer mast required to carry the tension worked against the sail.
in both cases the original reason was to save money on a traditional rig, but both the yachts were later re-rigged and sailed well.
in the case of this landyact design , I reckon this could be a good cheap experiment that would be well worth the effort, and may have some suprising results
We will see if it is a good surprise or not. Planning on building the frame this weekend. One thing on my mind is whether or not the sail should have battens or not. Also am conserned if I will have a problem with mast bend under load.
Battens will help to stop the sail from flapping and inverting in the tacks. The only landyacht sail I have ever had without battens flapped a lot during tacks, and as that is drag, it also had the effect of making the front wheel go awfully light. Battens changed that. It did not have any roach to support either which used to be the main reason for having battens, now they have a function in pushing shape into the sail when forced a bit.
Are you using an existing sail or having one made?
Mast bend will only be an issue if it lets the luff go slack, which will also have an effect on sail shape. Personally, suck it and see! You can always add stuff to stiffen the mast!
Now that Bipod mast could be raked back at the top with one stay forward and one back, hmmmmm
I am searching for a used storm jib to use if possible if not I will make something. I have found a couple very close to my needs. That was the reason for my batton question because they do not have battons. I could always sew in some batton pockets though. I am also considering a laminated arched rear axle. I think that properly placed spreaders will help to keep mast straight if it is an issue. Should have chassis built this weekend. I will send pics.
