|610 N. Whitney Way, Suite 160
Madison, WI 53705, U.S.A.
Phone: (608) 238-2171, Fax: (608) 238-9241
We received the following note from a customer using PLS-CADD and SAGSEC:
"I thought you guys might find this interesting.
Attached is a photograph of one of our 500 kV lines. Generally, we try to keep the conductors a little higher off the ground than shown in this picture.
This is an example of a clearance problem resulting from unequal ice/snow loading. The adjacent spans are clear of ice/snow. I have a reasonably good ground DTM so I modeled this ruling span section on PLS, then exported to SAGSEC, pasted the resulting sag back into the PLS model and bingo....sure enough, this is what we would expect to happen.
When these lines were designed and built (long before the PLS era) we only checked unequal loading for structure loads, not ground clearance. Primarily because we didn't have the capability. No excuses now."