Buzz Singlehanded Project

To add a little to the equation--additional righting moment is of no value unless the boat is overpowered.  This condition begins to occur in the Swift at about 11 knots of breeze for lighter sailors and about 13 for guys my size.  Because of the flexi mast and on-the-water mast bend control / mainsail design, adjusting the rig takes the boat up to about 20 knots before depowering requires feathering the sails to the point that some luffing occurs.  Installing wings or adding beam to the Swift in winds below 15 knots would only cause more drag and make the boat more difficult to sail.  

The real issue is tacking.  Righting moment plays no role when the boat is head to wind.  Drag caused by sails and rig do.  The clear difference between USA 001 and USA 002 (30 lbs lighter) put the brakes on any thought of reducing the weight further.  Keep in mind that one of our primary goals is to have a boat that pays little price for tacking and gybing.

Regarding using balsa, Nomex or some other cores:  We considered using Nomex cored hulls and decided against it.  We are reasonably convinced that because the hull is mostly rig loaded in tension, these hulls would not significantly change the numbers on the forestay test described above nor would the results change much over time.  We are equally convinced that using another core for the deck would do both because of the compression loads in the quadrangle.

I would hope that further discussion regarding composites would be centered on the validity (or lack thereof) of the forestay test and actual experience.  If you think the test has merit, then taking the time to test the class boats at your local club will be educational.  I believe that you will find the correlation between the amount of use, softness, and core material hard to refute.  You'll probably be limited to the Thistle class and a few others to draw conclusions regarding different core materials.  Remember the qualifier "all other things being equal" or the discussion is without merit.

   Bram

If you are trying to get a hull to stay compettitive for 10 years then stiffnes is not the only thing you need to worry about, weight is also important.

I had a balsa cored hull that lost about 3KG over a winter spent in a heated garage it had put it all back on again by the middle of the season. Foam cored hulls do not seem to have quite such a problem.

It was an old boat that had had a hard life and spent several cold winters with water in the hull before I got it but I was amazed by how much water it took up.

Thanks for your interest. I only replied on this forum initially on a whim and didn't take the time to put any information on my profile. As you can see I am based in Australia.

I hasten to add that I haven't sailed one so these thoughts are not based on actually "being out there" but the following thoughts might be worth thinking about:

• My current boat the 59er carries an almost identical sail plan and we do ok in 25 knots. I weigh 93kg and my crew is 60kg. The 59er also is about the same beam as the SS - 2 metres. I am not a maths guru but I would hazard a guess that we would exert about the same righting force hiking out as I would alone in the SS on the trapeze.
• To tack the Musto one has to move aft to get under the boom. The Swift is a run through design in the tradition of the 49er.
• The Musto has a wider wingspan with soft material between the hull edge and the wings. The Swift due to its narrower beam can provide the required beam with hull flare creating easier rail to rail movement.  
• If you examine the sail plans carefully you realise that when you exclude the the kite that the Swift carries 14 m sq against the Mustos 11.4 m sq Not a huge difference. In addition the Swift's sail plan is a lower aspect than the Musto as it carries a jib which goes down to deck level.
• I agree that the kite is a lot larger than the Musto but this will simply mean that you will go lower and faster as you use steer for balance techniques downwind. A cat rigged boat cannot carry a kite this big for balance reasons (too much lee helm) I agree that you won't be using the kite for tight reaches!   
• The Swift is slightly heavier than the Musto which should mean less loss of momentum when tacking. 

No I haven't seen pictures in a big breeze either and where I sail it is 15 to 20 knots a lot of the time.......................... Time will tell whether I can handle it!!

Cheers

Steve

You might have big sails but without righting moment you will struggle in higher wind speeds and rough seas.

Are there any photos of the SS doing the business in a breeze - all the pics on the site are on lakes in light winds - I guess that is what you usually get and have optimised for that.

Rick