Thursday, April 5, 2018

Playing with different rig layouts

As everyone following this knows I've been wondering how much sail area the Robbsboat really needs.  The originally designed 138ft2 on an 18 ft mast is definitely too much around here.  I built the original tarp sail @ 120ft2, and only needed the full area on the very lightest of days.  I spent most of the time on the first reef, which was @ 95ft2.  I finally decided to Have Mik Storer build me one at 100ft2.

The sail above is what I ordered, complete with the three reef points shown.  It's shown above on the 16ft mast I actually built using Jim's originally designed 5 degree mast rake.  Here's how it looked the first time I rigged it in the Driveway.





Here's one still show from actually in the boat


I sailed it for the first time on the Columbia river between the I-5 and I-205 bridges on a light wind day.  My velometer in the parking lot was ranging from 3-5 knots of wind with an occasional little gust up to 6 or 7 knots.  I headed off downwind against a 1 knot current, and maintained a speed between 1.5 and 3 knots, even with only 100ft2.  It's enough, especially with the improved aerodynamics of a properly cut sail.

Here's a video of that sail.  Too little wind to be very exciting, but it shows the shape of the sail and the experience of sailing it Paradox style from a beach chair with steering ropes.  I've pretty much decided that's how I'm going to operate it most of the time.  The going back and forth on tacks is hard on my 55 year old knees, and the boat is so narrow I don't pick up THAT much extra righting moment.  I'm better off reefing when my weight low and centered isn't enough.





New entry, surgery on the aft of the cabin to make it easier to operate the kicker.

4 comments:

  1. Got Robbsboat plans myself.... and have built a Reddish sail out of polytarp in the past. I'd far rather have the junk sail myself and have sailed two junk rigged cruisers. The reefing alone will work out well. Thanks for working out the dimensions. Great article on Duckworks re poly junk sail with mods that make it go well to windward. As I recall 10' battens on one of the 2 sails he supplies dimensions for in the article. Curious if you think a small mizzen is worth it. One junk rig I had the mainsails sheet runs landed along the mizzenmast and worked well. Glad someone already blazed a RobbsBoat build path.

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    1. Robert,

      I find I can dial the helm pretty well with the Barrel/downhaul arrangement to move the CE on the main. The time I really want the mizzen is when hoisting in significant breezes. The mizzen would really help keep my bow into the wind for that part.

      Tom

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  2. Like Robert, I also appreciate your blazing a Robbsboat build path. On a relatively narrow boat like this, quick and easy reefing seems like a great modification, so I'll be interested in hearing how the junk rig works out. Should be good.
    We're back in Oregon for the summer (Corvallis). If there's sometime when you're taking the boat out and would be willing to let me come along for a short sail, I'd love to see how she does on the water before beginning a build.

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    1. David,

      Happy to take you for a sail. Too bad you missed the Coot's mess about at Fern ridge a couple of weeks ago. Actually you didn't miss out really, there was almost no wind that day. If you'd like to catch one of the many small boat gatherings around, you should follow the Coot's messabout calendar. I'll be at the Hagg Lake one on July 8th.

      http://www.coots.org/index.html

      After the river levels fall a bit, I'll be out on the Willamette and Columbia fairly often if you'd like to make the drive up. Usually pretty dependable wind there.

      Tom

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