NS SD40-2s 3342 and still blue 3336 help manifest 11A up the east slope of the Allegheny Mtns. and around Horseshoe Curve. Another set of helpers are shoving on the rear.
You can really see the grade on this telephoto shot. The tale of the train is still coming over the hill, while the helpers have just crest the grade and are heading into the "Slide."