Jib Booms

[Boots]

After unsuccessful attempts to "tune" my radial jib fitting(and it's cold in Nova Scotia) I've gashed it and want to goto a deck swivel. Are there measurements somewhere for a starting point to begin tuning? The boat had a backing plate already installed and I've placed an aluminum "T' with multi holes there but how far back on the Jib boom should I be?

[s vernon]

http://ec12.net/EC12Plan/plans.htm

The link is to the full sized pdf of the construction drawing. You can see 7 3/8 on the boat and 4 inches on the boom from the clew of the jib at the boom to the jib swivel point on the boom. You might find that you need to move the jib swivel hook maybe one (or more) hole forward or aft some days depending on the wind and the tune of the sails - wind strength - sail draft - twist - in order to get the sails in harmony sailing upwind. It is probably better to try to adjust the sail tune rather than move the jib swivel hook. Moving the jib stay hook can be the expedient way to make the boat behave (helm).

All of the numbers on this plan seem to be good except the location of the jumpers which is much too low. Jumpers should be at or just above or below the jib stay mast exit point. There is an old thread on that subject on this discussion group.



Scott

[Boots]

I'll start from there. Thanks it's hard to measure with gloves on

[mgbrown]

What is the advantage of a spring loaded boom vang?

[greerdr]

In very light air it holds the boom up but allows compression to "vang-sheet".

R.C.Greer