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Methods of attaching leeboards to hulls

by Peter Belensky (with permission)

One thing that is absent from your site so far is a discussion of the methods of attaching leeboards to hulls. There are essentially four approaches.

The first, suitable only for small boats with light boards is a loose attachment through a bight of rope.

Second is a bolt through the board and hull. This requires heavy construction of both, since the strains created by the board’s leverage can be enormous, particularly if the weather board is not raised in time. Philip Bolger has designed a number of boats with a large radius at the head of the board and a corresponding flat surface on the hull to distribute the strain of a board pulled away from the hull.

The third approach, identified with L. Francis Herreshoff in such designs as Meadowlark and Golden Ball is the hang the board from straps pivoting around a T-bar welded to the end of the bolt through the hull. This eliminates the twisting strain on the bolt or flexing strain on the board, but if the weather board is only partially hoisted, so that it remains in the water stream, the water pressure may tend to pull the board outward, dragging it against the restraint of the hoisting tackle.

The fourth approach, used by Bolger (and identified by him as Dutch geometry), is to fix the pivot bolt, not through the hull, but through a block or frame on deck. This block pivots around a second axis parallel to the centerline, so that the board can swing away from the hull without restraint, regardless of the extent to which it is hoisted.

It would be interesting to see photographs or designs on your site of all of these options and discussions of their history and dis/advantages.

More coming soon.

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Disclaimer: Always wear life preservers, drink and party responsibly, sail at your own risk, and please pass the word that leeboard sailing is now a blast from the past that will soon be in the news as being the latest sailing craze.