[MarkG]

The out of box thinking here, at least for me, is splicing a dumb sheave onto a shroud to gain mechanical advantage. So let's invent some shroud fittings to take advantage of this.

The upper fitting (upper deadeye) has two dumb sheaves, sized correctly for the shroud. An eye splice in a short piece of shroud goes around the dead eye. The tail of this line is then spliced into the shroud an appropriate distance above the deck.

The lower fitting (lower deadeye) also has two dumb sheaves. A simple winch, with a ratchet that allows the drum to turn only in one direction, is on one side of the deadeye, A cleat is on the other side. The deadeye is attached to the chainplate. The winch should go where it is most protected, even if this makes winching inconvenient.

The shroud goes through the lower deadeye and upper deadeye twice, giving a 5 to 1 mechanical advantage.

The shroud then goes to the winch located on the lower deadeye. As many turns as possible are taken on the winch. Then, with someone tailing the shroud, the tension on the shroud is adjusted. Loosening the shroud is done by manually lifting the ratchet.

The end of the shroud is then secured to the cleat. The tension should be low because of the winch turns. If possible, the cleat should be designed to store the tale of the shroud securely.

The lower fitting could also be modeled after a come-along with a removable handle. One end attaches to the chainplate and the other end to the deadeye. The shroud end is attached to the come-along drum which also provides secure storage.

A third option for the lower fitting would use a worm gear turning a drum. This has the fewest parts, has a really large mechanical advantage, stores the shroud tail, and locks the drum in place with no pawls. The initial take up of of slack would be slower, but that is not much of a penalty. If the winch is strong enough, deadeyes would only be needed for really high tensions.

The intent is to provide high, easily controlled, shroud tension. It might even replace turnbuckles on larger boats.

Thoughts? Did I miss something that makes this impractical? If it is practical, what are the disadvantages?

Mark Gardiner