Join Date: Nov 2006
Location: Nanaimo, B.C., Canada
Thanked 1 Time in 1 Post
Rep Power: 9
Help with Actual Use of Backstay Adjustor
The backstay on my boat is the "inverted Y" type of backstay with a 6 to 1 block and tackle on one leg of the Y (giving what I think is an approximate 12 to 1 mechanical advantage overall). The rig is a 9/10 fractional rig with only one lower shroud (each side), with swept back spreaders and a roller furling genoa. The wire sizes are 7/16" for the backstay, and 1/2" for the shrouds (lower and cap) and 5/16" for the intermediates (total of 2 spreaders). It is a production cruiser type of boat (sloop rig). I can't seem to find a loos guage for determining tension that will accept wire this thick?
The information from Selden on this rig, is that the backstay should not be tensioned more than 20% of it's breaking strength (at any time), and that it should never be allowed to completely slacken.
My questions are:
How do I tell what level of adjustment to use? When do I use the full 20% tension and how do I tell when I am there? For downwind, how much do I "let it off"? In light wind, how much do I let it off?
For example to loosen for downwind, do I let 3" of line through the 6 to 1, or ??? from the fully tensioned position?
Up to now, I have avoided using the backstay adjustor, probably because I am unsure of how to set it properly. I am not even sure how to tell when it is tensioned to the 20% of breaking strength point.
Thanks in advance for your advise and help in "demystifying" this control,
Point Roberts, Wash. Marina
To view links or images in signatures your post count must be 10 or greater. You currently have 0 posts.