Self Tacking Headsails
The self tacking headsail is a very useful sail for cruising in crowded waters such as Sydney Harbour. It is surprising that there are not more in use.
One problem is that no one seems to know how to set them up. The following should help you in this area.
The minimum horizontal sheeting angle should be at least 10 degrees to the centre line of the boat. For example, with a 3.5 metre fore triangle the sheet anchor point at each side needs to be 0.607m from the centre line. The theoretical radius for the track is LP plus the distance from the clew to the track.
Liberties can be taken with the latter particularly if a forward sweeping sheet connection is used, some correction can be made.
Vertical sheeting angle has to be determined carefully as it is difficult to provide adjustment. A few shackles in the tack will help the initial set up.
When the headsail is roll reefed, the vertical sheet angle can change. It is for this reason that we developed and patented the MACLEW. This, within limits, maintains the vertical sheeting angle as determined by the sail maker when designing the sail.
The options for sheeting are;
- Deck sweeping from forward of the attachment point - fouls everything on deck.
- Similar system with attachment point up the mast.
- Sheet originating at each end of the track - most critical to get right, but the best.
The track must be fastened with strong brackets. This is very much a job for a yacht designer. If the track bracket fails or worse, pulls the coach roof apart then seaworthiness will be compromised.
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