"DSK" wrote in message

| Why not? If the boom can take the torsion in one direction, then unless
| it is a very weird asymmetric structure, then it will take the same in
| the opposite direction.

This is where you stray from engineering principal... that is not the case
at all nor is it the rule.

| Sure it is. It's exactly the same in both directions.

No Doug... it is most assuredly not the same in both directions if only by
the points of compression
|
| What I'm saying is the same as saying if you can stand on a beam (let's
| say a 2x6) between two sawhorses, and it doesn't break, then you can
| turn the beam over and still stand on it. You're saying that it doesn't
| work that way, if the beam doesn't break one way then it will definitely
| break the other...

That's not at all what I said and again you are attempting to introduce the
boom as a factor... that is not good methodology for what we are discussing
here.... forget the boom or assume it indestrutructable and unbendable.|

| The max forces are limited by the righting moment of the boat. On a 30
| footer, it doesn't need to be that massive. On bigger boats... take a
| look at the vangs on IACC racers...

Nobody is discussing righting moment here Doug... we are discussing the
ability of basic mathematics in regards to the placement of the vang and the
loads you expect it to encounter.


| Actually, I have. It's not that complicated. Try drawing out a diagram
| of moments. If you need a refresher
|
http://www2.umist.ac.uk/construction...xp/sfbmdex.htm
|

No Doug... it's not that I refuse to seek knowledge but this time you had
better be able to logically explain your theory to me without a jaxxian
reflex to google proof that may or may not have bearing on what we are
discussing.



| No, it isn't... but it is holding down 100% of the leach tension, which
| is very large. It also takes all the load of the mainsheet when hauled
| in tight to go to windward. If it doesn't break when you honk down on an
| 8:1 purchase, then it should hold at least 8X your honking strength

No Doug... it is most certainly NOT holding down 100% of the leech
tension... that load is divided with a bigger factor attributed to the
mainsheet.
|
|
| For using the boom as a lifting device.... you will stress the vang
unduly
| with a set-up located that far back on the load arm.
|
| ???

Well come on now Doug.... it's basic common sense engineering principal!

| ... It's not designed for
| that.
|
| It should be. Anything less would not be safe for sailing IMHO.

No it's not... it's designed as a VANG!


CM