I was always a regular reader of Brion Toss' forum. I was disappointed when it became too much trouble to maintain. Lots of really good information buried in there. He is one of the people I have "met" through his writing who I really would like to meet personally.
Can my boom hit the backstay? Yes. But... No.
YES: The geometry of the rig would allow the boom to hit the back stay. (I just had to go on deck to check.)
But NO: Amel, having thought of everything, has put a "permanent" vang on the boat. A length of 3-strand nylon (stretchy!) from the boom to the base of the mast. Its primary purpose is to keep the boom from rising when unfurling the sail. It also prevents the boom from rising high enough to impact the backstay in a jibe. It is long enough that it has no real effect on sail trim in any normal situation.
Annapolis, MD, USA
, wrote :
Thanks for your input and advice. That is a good point about being sure to bring the traveller all of the way to the leeward side when sailing at an angle that could possibly result in a gybe.
I am curious about whether the boom on your boat can actually hit the backstay? Have you tried raising it using the topping lift, then swinging it back and forth to see? The main boom on my boat clears the backstay even when lifted so that it is perpendicular to the backstay, but not by much!
On the subject of shock loads (such as from jibing) and elasticity, I came across this snip from a forum response by Brian Toss whom I feel knows his stuff pretty well.
"Shock loads are relative to acceleration and elasticity. They can be quantified and included in design load calculations if desired. The short form here is that the materials you are likely to use appropriately are also appropriate for any shock loads, if they are scaled to the design load, times a safety factor. As a counter-example, I've seen main sheets and vangs break gear when owners ill-advisedly replaced Dacron with HM line.