Tuesday, September 20, 2016

____________________ SAILING CLOSE TO THE WIND ____________________

 In a previous post I explained how I was enlarging the area of the Starlings centre board here:

A narrow central piece of pale pine timber has been laminated into the middle of the centre board and two dark mahogany pieces added fore and aft at the bottom. The operation was a little tricky as the centre board has an aerofoil shape - but sighting by eye after the major operation shows that things are aligned well. I am hoping the added width and depth will allow the boat to sail closer to the wind giving added windward performance.

The first application of a couple of coats of primer paint. This will be followed by an undercoat and final finishing coat - with judicious sandings in between coats. The season begins this Sunday with the 'Round Limestone Island Race' (Three circuits of the island). I hope I am not sailing too close to the wind in getting this modified centre board ready by then.


D said...

Good job so far. I'm sure you'll be faster to weather. When I sailed lasers I swapped out the laser rudder blade for a Hobie Cat blade. What a difference that made. No more death rolls. Foils make a huge difference.

Alden Smith said...

Thank you D for your comment and sharing your experience. I am encouraged by what you say. I am sure more area in the rudder would also be useful especially controlling the tendency to round up when hard pressed on the wind in very gusty conditions, but I am of course bound by the class measurement rules if I want to race against other Starling sailing dinghies. The alterations I have made to the centre board bring its measurement up to the maximum allowed by the rules.

Ben said...

This work looks like a nice piece of craftsmanship.
What could be the reason that the original centreboard was that much smaller?. I assume that the measurement rules did not change.
The shape of the aerofoil and the thickness of the centreboard could also contribute to less or more friction. Are there some optimisation possibilities? Is there a thickness limitation in the class rules?

Alden Smith said...

Ben, that is a good question - why was the centreboard that much smaller?

I don't think the measurement rules have changed.

Maybe a much lighter skipper was able to maintain good windward performance with a smaller area centreboard and gain the advantage of less wetted surface area, thus reducing friction - but I really don't know.

The rules for the centreboard are thus:

"12 Centreboard
12.1 Materials and design are optional.
12.2 The centreboard must float.
12.3 The blade under the cheeks or stopper device must fit inside a rectangle
1067mm x 280mm and have a maximum thickness of 20mm. "

The maximum thickness of 20mm cannot be exceeded because anything thicker would not fit through the centreboard slot in the boat.

My centreboard now measures 1067mm X 280mm and I hope it gives me some increase in performance - time will tell.

If I don't gain any increase in performance at least the longer centreboard will give me more mechanical advantage by increasing the lever arm when I am swinging on the centreboard trying to right my capsized Starling!!