High-Speed Sailing

Vessel Name: Sailien
Vessel Make/Model: Experimental/custom
Recent Blog Posts
28 September 2013

The America’s Cup

I watched, with interest, the videos of the 34th America’s Cup. At last we have fast sailboats engaged in a competition that is fun to watch. The virtual images (such as course boundaries, distance grid lines, separation between boats, etc.) overlaid on the real images really helps to keep the race [...]

31 August 2013

100 Knots for Hydroptere?

The latest news from Hydroptere is that they have plans for a 100 knot sailboat. This was posted on 26 Aug 2013, so look for that date at this address. http://hydroptere.com/en/the-news/last-news/

17 November 2012

Aptly named Sailrocket, blasts off!

While yet to be ratified, Sailrocket posted an average speed over 500 meters of 59 knots. I will not be surprised if they increase their record into the 60 knot range during this record attempt.

02 January 2012

More drag for VSR2?

I want to start by pointing out that the whole VSR2 team has done a stellar job and has demonstrated conclusively that the forces that drive a sailboat can be aligned for roll stability without using ballast and without using any down-force. (Trifoiler achieved roll stability by using down-force, but [...]

18 December 2011

My analysis of Sailrocket

I copied a diagram of VSR2 (wing doesn’t show well) and added in the major force arrows that apply. Be aware that these arrows are not correct in terms of scale (length) and some of their locations are guesses, however I believe I’m correct enough for us to learn something about what VSR2 has been [...]

23 October 2011

60 is within reach, what’s next?

I have been watching Sailrocket’s progress with great interest and there’s no question they have a winner. I fully expect to see them reach 60kt in the near future. Sailrocket has now demonstrated what I first learned with my models and again with my full-sized prototypes, that if you get the forces [...]

More notes on Sailien

15 May 2011
I’ve been following Paul’s blog on Sailrocket’s website and wish I was part of the fun. Note that they have been struggling with low-wind speed performance. This is unfortunately a major problem with high-speed sail craft. The fast sailboards sink if they are not planing and need about 15 knots of wind to sail. Similar for the kite-boards, but I believe they can get planing in less wind. Trifoiler went out of production by Hobie in part because of relatively poor low-wind performance (Ketterman told me he needed about 12 knots of wind to get up on the foils.) The foiling Moths have this problem as well, and so it goes.

I’ve been struggling with the same problem with Sailien, and improving low wind-speed performance has been my main goal. With sufficient wind, going fast was never a problem, since I had essentially eliminated the “normal” sailboat stability problem. I suppose that I should point out that I’ve never gone as fast as Sailrocket; my craft were too crude, but good materials, good structural engineering and good fluid dynamics would have solved that.

My main research has been how to design a practical craft that will sail well in the lightest of winds and be able to controllably handle high winds at high-speed. I’ve been doing this by searching out the best configuration and inter-relationship of the parts, and how best to control the craft. You can see the configuration I’ve been working with in my recently updated You Tube video (added prototype images near the end -- link on the right of this page – Sailien Video).

By designing my craft so the airfoil can rotate 360 deg., I can freely tack or jibe the sail, and just as freely rotate the keel. Note that the rig always stays to leeward (proa style) but since the keel rotates, the craft does not shunt (unlike a proa) and it does not slow to change tacks (when jibing). To be continued.

Bob
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