Thread: Fastest rig?

There's no such thing as the "fastest rig". There are rigs that are better suited to certain types of sailing, racing rules, rating rules, sailing habits and of course, the big catch, personal sailing preferences.

The fastest sailing rig currently employed and one that clocks over 80 MPH regularly, plus a top speed in excess of 100 MPH, is a very high aspect ratio rigid sail, equipped with a leading edge slot, which is also hard.

By hard, I mean there isn't any sail cloth. Most are made from high modulus fabrics (carbon tow and Kevlar, typically), but quite a few are also wood. These rigs are "uni" rigs, in as such as they have a single wing (sail) which looks much like a wing from a glider was ripped off and placed vertically on a racer.

I've sailed dry lake versions of these machines and they are blindingly fast. Traveling at 80+ MPH with your butt a few inches off the lake surface will get your blood moving along at a good clip.

Everyone that sails, has a preference, none as well suited to others as their own selection. Some commonalities (okay, I cracked open the door for Michael) has caused certain rigs to be favored over others, but it's a complicated subject. The moderately high aspect Bermudian rig, either as a fractional or masthead sloop is currently the most popular rig. This in itself suggests it's one of the best, but this is a well debated and subjective argument. One could easily argue the complexity of the rig means it's not the best, but this isn't addressing speed potential, just cost effectiveness.

In a nut shell, the fastest rig is one that has the bare minimum windage, and most amount of lift. This is true of the hard sails, the dry sailors I was using last summer and also of some ice boats. The frictional loses of these sailors, is much less then water born counterparts, in part raising their speed potential. When these rigs are placed in boats, they exhibit the same abilities, but have resulting speed reductions, mostly governed by additional friction and wave making resistance.

All rigs, regardless of type and configuration have good and bad points about them. The best thing to do is get out and try as many different types as possible, making judgments based on your own personal reflections and observations.

Howdy Gyula,

I am highly sceptical of all these types of tests. There are too many variables that are not controlled.

Also people make little effort:
1/ To really rationalise what they are testing. If I was in the same situation I really don't know what I would compare. There are too many interrelated variables to actually work out what is making the difference. Are they testing rigs of the same ....
Sail area
Heeling moment
Cost
Mast Length
Aspect ratio
or something else.

2/ To actually work out the best way to set the sails in the different rigs - I look at the examples given in the pics and I can see how I can get another 10 or 20 percent out of each one. How do they expect at boomless rig to go well downwind at all? And of course the sprit is going to project more area downwind compared to any rig without a stick of some kind perpendicular to the mast.

3/ To present the results in an honest way. They show some lovely polar graphs with smooth curves. The scientist in me wants to see the scatter of actual data. They said

The results showed considerable scatter and it was difficult to deduce from them the true pattern of difference between the rigs

But then they publish the neat polar diagram and say the sprit rig was faster to windward than the bermudan by 30%.

This is an impossibly big difference, particularly after having problems "deducing the true pattern of difference".

4/ To actually know something about the geometries of the best performing rig of each type. The proportions of each rig here is so arbitrary - the rig that is supposed to be representative of the bermudan rig is about as far away as it is possible to get from the most efficient of the type. Why do three of the rigs have a jib but one does not? The lateen is highly compromised by not having a boom and the rigging restricting the sheeting angles. Also it looks like the jib sheeting angle is away from optimum for some of the boats too but not for others.

Most people don't know enough about setting sails properly to do these sorts of tests and the theoretical underpinnings are usually poorly thought through.

There are two main things that make sails work properly independent of the type of sail.
1/Control of sail twist - this is probably the big one ... the people who are not aware of this as a speed producing factor will be left behind by those that do. It tends to be overlooked because it is not obvious.
2/Amount and position of sail camber (depth) - with most sails that are more or less cut ok some relatively small adjustments can make quite big differences to the performance of the boat.

But apart from all my grumbling.

Would have been fun to be on the water to do all that SAILING!!!!

Best wishes
Michael