Damn... I should have said something.. that's what I had on the vang for my
Cal, except that it wasn't a rigid vang. :-(

--
"j" ganz @@
www.sailnow.com

"Bart" .@. wrote in message ...
4 points to you Walt.

"Walt" wrote

Bart wrote:
You have a rigid vang. It is rigged with a wire
rope from the base of the mast, through a sheave
at the boom, and then to a rope purchase that is
a double becket block and lead down to the
mast base with another double block. The rope is
then lead to a single block at the mast partners and
then to a cleat aft of the mast.

What is the purchase ratio? [1 pt]

The block at the mast partners is not actually on the mast, right?
Ok, then that's just a turning block, so it adds no purchase.

The double blocks provide a 4-1 purchase. The cascade above doubles that
for 8-1. And that's my final answer.


What is a simple way to determine any given
purchase ratio? [2 pts]

Count the lines. Multiply by 2 for each simple cascade. If you are
using a multi-purchase system to pull another multi-purchase system,
multiply the two together. For instance, a 4-1 that pulls on a 3-1 is
12-1 overall. In the example above, a 4-1.

But when you count lines, don't count the ones that merely change
direction without providing purchase.


Since your mainsail area is large, you decided you
want to increase the final purchase, name a way to
do this? [1 pt]

Add a cascade to make it 16-1.

// Walt