That would be the tension in the guy wire when it is installed. Depending on your application, it may not make much difference. However in some applications it could be critical. If the initial tension is high for a guyed tower and the temperature drops significantly, it could buckle the tower. That may be an extreme example, but hope you get the point. There is quite a bit of information out there, what is your application?
For guyed wood, concrete and steel transmission poles, we use a pretension of 2% of the ultimate guy tension. What program are you using to do the structural analysis?
_____________________________________
I have been called "A storehouse of worthless information" many times.
