Here are a couple pictures and a video of Norfolk Southern train 211 from yesterday. As I heard the horn as the train was approaching, I thought it might have a foreign power leader, but I think this NS dash 9 has a Nathan K5H horn for some reason. Thanks to Alex G. for help identifying the horn!
Photos
NS NS D9-44CW #9058 leads train east near Linden, Va on 1/31/2017
NS NS D9-44CW #9058 leads train east near Linden, Va on 1/31/2017
Video