F Tower, Fostoria, Ohio, 1984.  This location is one of the busiest rail crossing/junctions in America.  Two CSX lines (one the former B&O main line to Chicago and the other the former Hocking Valley/C&O line north to Toledo) cross the Norfolk Southern main line (former Nickel Plate Road).  Until about 20 years ago, the PRR's route to Toledo and Detroit, as well as a Lake Erie & Western line crossed these lines as well.   [Charlie Whipp]