Phils Rig School continued...

It's different from just moving the boom up and down the mast because it would allow the top of the mast to go higher / lower thus increasing or decreasing the projected area of the sail but compensating for that extra projected area by flattening the luff curve when you increase the projected area.....

I'm guessing (as I'm no spar designer) that side forces would have to be resisted via the design of the 'collar' or overlap between sections, in much the same way as the current carbon/composite two piece masts are.

I'm just missing the windglider reference....

I think Grumpf's projected rig would be way too heavy and have way too much windage to work. Not only that, but there's no real reason to standardize masts in dinghies, as they are aimed at vastly different groups and there is vastly more variation in righting moments and sail area than in boards.

The smallest regularly-used board rigs are about 4m; the largest are 12.5. In contrast, there are tens of thousands of dinghies with 3.5-4m sails, many with 30m2 of sail, and some with 60+m2 of sail. So board rigs handle a variation of about 300%, boat rigs work over a variation of about 1700%.

The lightest boardsailers are about the same weight as the lightest windsurfers, but lots of dinghies carry three crew, so the weight range is about 3 times what a board has to handle. And righting moment in a board varies from about 160 ft/lb to mebbe 800, whereas righting moment in a boat varies from about 320 ft/lb to over 2000 ft/lb.

So in almost all areas, boat rigs have three or more times the variation of board rigs. It seems to follow logically that you cannot throw them all into the same basket.

Let's add in practicality....you can pick up and carry a board rig and chuck it in the water. You don't pick up and carry a boat rig in the same way. If you change some things, you can harm a class. When 12 Foot Skiffs developed sailplans that had to be rigged with the boat on their side, the class became extinct at three clubs where the rigging space was too restricted. Good idea?

The sailboat rig is a great thing. MArk Drela, a famous professor of aerodynamics from MIT whose plane and foiler designs hold world records, has told glider design groups that they should envy boat rigs, because the ability of a boat rig to adjust camber, angle of incidence etc is vastly superior to any aircraft wing ever designed. When an acknowledged guru of aerodynamics speaks, reasonable people listen.

Board rigs can also be great, but they have issues. In many ways they are less controllable than boat rigs; you can't adjust draft, twist etc on the fly as well. You often have to buy a new mast to rig to a new sail, rather than just tightening a wire or two.

If board rigs were so much better, then the most advanced racing board rigs would have developed a big edge over comparable boats. They haven't. In many conditions, even something like a Laser will slaughter a board, even a Raceboard.That's not the sign of a vastly superior design.

PS - variable-height mast collars were used in Aussie 14s, 1988 period. So was a "structural" mast and a non-structural fairing (1930s, 1970s) Neither are used any longer.


Edited by Chris 249

I've been doing a bit of Raceboarding again recently, and a lot of racing against Raceboards on the One Design. There's no evidence that your Raceboards are faster than the ones down here (or vice versa). With recent wins in Formula Worlds and runner-up in the RSX worlds, there's not much doubt that we have a pretty good high standard in boards (as do you). At the last OD nationals we have three current Olympians (from two countries) and two former Olympians and they averaged about 6th place, so we're not sailing too slowly.

So, racism and ancient jokes apart, there is simply no reason to believe that what we see from Raceboard performance is any less accurate than what you see. And what I see is that on confined waterways in light to moderate winds, a Laser can whip a Raceboard upwind because of its ability to tack faster and point higher when underpowered. And this is from the vantage point of being a successful sailor of boards and Lasers, in a club with 47 registered Lasers and about 35 registered boards. We often get 40+ of the two classes sharing a course, includng sailors who have been on the podium at titles from states to nationals, worlds, World Cup and Olympics. 

Of course, in other conditions (perhaps like those at your club) a board is miles quicker and the world's best Laser sailors are legs behind; even a Windsurfer One Design will pace the world Flying Dutchman champ upwind in a 20 knot breeze and a slop. But the point remains that in light shifty upwind stuff, a Raceboard is in trouble from what I can see from a very good viewpoint.

And yes, of course a windsurfer rig can alter camber on the fly. But a good boat rig can also alter camber on the fly, and it can alter twist without altering camber or with altering camber, because there are more controls and more independent controls that allow you to alter one thing without altering the other.

A board rig does what it does well, and a boat rig does what it does well, That's no great drama.

Sorry, but try winning a Laser title and board titles and then you may have a better basis of comparison about the performance of the two classes. And try playing with a Flying Dutchman rig, or a yacht or skiff rig with someone who knows what they are doing, and you'll surely be impressed.

Boat sailors are not morons, nor are boardsailers. Both are under a lot of pressure to develop.


Edited by Chris 249

I think you're right there Skiffbob.  I've got tapered foam battens, an over-rotating wing mast, a hull that is on its 100th design iteration (or thereabouts), sails from a world renowned sailmaker (designed by a World champ/Olympic medallist, and made in Germany) and total freedom of choice when it comes to controls, innovations and developments. And all for less than the price of a RS200.

Maybe the RS100 should form the foundation of a development class?

Please no...