Tuesday, October 18, 2011

Balance Lugsail - Setting up a Downhaul

One of the great pleasures associated with owning a home-built, traditionally-rigged boat is that you can fiddler around with the running rigging for years and years. My old boat is forty years old and I'm still altering details of the rig. It is educational, fulfilling, and wholesome activity!

My old boat running home in 30 knots of wind, with the main reefed. Everything in the rig, with the exception of the sail, is homemade and home-designed.

Here are some photos which illustrate the downhaul arrangement that Paul Hernes has developed for his Phoenix III. Control of the downhaul is critically important in getting good performance from a lugsail, and this arrangement allows the downhaul tension to be controlled by a single-hander in a very simple fashion. Additionally, this downhaul is also used to tension the snotter when Paul is using the larger spritsail, so one piece of simple equipment does two separate jobs - and does them both efficiently.

Here you can see the four-part downhaul made up of common polyester braid and two cheap stainless steel vang blocks. Note how the tackle is attached to the rugged mast partner, and the running end passes down through the mast partner........
...and on down to a turning block set low in the boat.
From there, the downhaul leads aft through a hole in the semi-bulkhead and along the centreboard case bed-logs.......
....and terminates in a cam-cleat on the aft end of the centreboard case. This is within easy reach of the skipper and can be tightened or released in a matter of seconds.
This picture shows the simple attachment to the boom. Paul has used a very strong-but-light piece of Dyneema (or Spectra) but for a short length like this anything would do, as stretch would not be an issue. The attachment to the boom can be a loop (as here) or a rolling hitch. The important point is that the attachment can be moved forward or aft along the boom at will, allowing wonderful adjustment of luff and leech tension.
In Paul's arrangement shown in the photos, the boom is simply held close to the mast by the tension of the downhaul. However, there are plenty of other options - in the above drawing is one that I favour as it holds the boom securely against the mast and also allows one to adjust the forward and aft location of the boom with ease.
 I encourage everybody to read widely and to experiment with all sorts of rigging options. If you are not constrained by the rules associated with a racing class, go out and have some fun with homemade equipment - it is cheap, and if you made it yourself you can obviously fix it as well. Usually all you need is some line and a few bits of timber - and your brain!

2 comments:

  1. A text, simply, wonderful goal! enlightening! Thank you, Ross!

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  2. Danilo, Thank-you for the nice comment. I am just learning how to post videos, and I hope to produce some more in the next few weeks. Maybe I will write a script instead of saying whatever comes into my head!

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