Originally Posted by tongabound
s/v Jedi - any advise on a good book for the rigging
Illustrated Sail & Rig Tuning by Ivar Dedekam. ISBN 1 898660 67 0
This is a thin book with all the information plus explanations. I never saw a better book, no matter how thick.
The things to pay special attention to are:
- a little rake aft is good. However, this means adjusting the base of the mast when the rake isn't there. This might be easy to do or not. How much rake and how to measure that is in the book (bucket with water
hanging from main halyard
, measure distance between bucket & mast etc.)
Rake is adjusted with fore and back stays.
- at least some bend. And I mean a bend to the aft (yes I did see masts bend forward). Adjusting bend is different for every rig-type. If you have square (not angled aft) spreaders, you use cutter
or baby stay or forward lowers in combination with back and fore stay.
With aft swept spreaders, the capshrouds (the ones that go all the way to the mast head) do the same. As they get tensioned, the spreaders push the mast forward.
- capshroud pre-tension. This one is forgotten by so many while it's the easiest to do. The book has a very clear explanation on this. The easiest way to measure this tension is by measuring the stretch of the wire. This is from memory: with slack capshrouds, measure and mark a 2 meter section. Now tension until that section is 4 mm longer. Now it is tensioned to 20% of breaking strength of the wire, regardless of the diameter of the wire. With spreaders that are angled aft, this creates the pre-bend in the mast. The lowers counter this bending but can often only be tightened when capshrouds are very loose so it's quite a job. A good rigger has a feel for this and can do it in just one or two tries.
- when in the marina, it is good to take the tension off the backstay and the jib
- check that the spreaders are okay: the capshrouds should have the same angle to the spreaders (under and above the spreader). This is almost never obtainable but pointing a little up is better of the spreader allows that. Pointing down is the recepy for loosing the mast. Spreaders are only designed to take compression
- when you have the "open-style" turnbuckles where you can see the threaded fittings, use a caliper to measure the distance between the fittings at 0.1 mm precision and keep that as reference for the next time. Much better than tape markers that shift or disappear.
Like Gord writes, pumping while not sailing isn't really a problem. While sailing it is a big problem and the cause for many dismastings. Spreader failure is high too plus of course chainplate failure.