from the poster;
"P80 is a local that transfers cars between Chamblee and Gainesville and mostly uses older equipment like these SD40-2's. On this day the train was very long and one of the units was having problems with the anti-slip system. This section of track is on a hill and long trains often have trouble with it. 154 for example has broken knuckles several times on this hill. If you walk down the track at Suwanee you will find several broken knuckles left rusting by the side of the tracks "