Sags & Tensions of Span Attachments
Starting Point
The three curves discussed (Initial, Final after Load, Final after Creep) are an integral component of determining the actual Sag and Tension values, but don't provide the values we need easily by themselves. To get started, we need a starting point. That is a known, measurable and verifiable condition along with either a tension or sag measurement. Something you could send a survey crew and possibly a Line Crew with the appropriate tools to measure in the field. This is critical to any calculation as it provides the linkage between reality and the calculations. As you already know, you can take any piece or wire or cable and get different sag values by changing its stringing tension. If you change this starting condition, all other load and material condition tests will yield different results for sags and tensions. So it is critical to know your starting point.