Updated 4/15/2012:
This low spot fixing thing has morphed into a full-blown adjustment of height, grade, track-joints, and electrical connectivity. It seems to have taken on a life of its own.
The large curve east of the bridge (not visible off the top edge of the figure below) leading to Weirton Junction is the ultimate focus of the fix. I've decreased the amount of grade there. However, I've also discovered that raising the entire section of the track from the Weirton Junction to the Weirton Steel yard (that's the light green track) will improve tracking and eliminate derailments. That's in progress. All that track is being relaid, including slight placement adjustments of the roadbed and wiring connections.
George