by GreenLake » Sat Jun 21, 2014 12:15 am
A mast jack is a threaded rod with a big bronze nut on it. It fits where the mast is stepped and the mast bottom has a hole where it goes over the rod (~1"). By raising the nut you raise the mast and increase the tension in the rig. It's useful for trailering because you just connect the slack stays, jack up the mast, and go. But the rig better be dimensioned perfectly, because there's no way to adjust relative tension port/starboard or front/shrouds.
I have one, it seems to work, but I can't be sure that the rig's tuned properly.
I've decided on the number of turns that seem right for the conditions. With Fred's finger-gauge, can compare. I may have left things a bit on the slack side, the leeward shroud goes completely slack in moderate winds (8-10), but as I can get a good twang out of the shrouds when they are tensioned, I never felt I wanted more. (Finger gauge will have to be tried).
~ green ~ lake ~ ~