A westbound SEPTA Paoli/Thorndale Line local on Track #4, westbound Amtrak Pennsylvanian (New York to Pittsburgh) on Track #3, and eastbound Amtrak Keystone Service (Harrisburg to New York) on Track #1 all meet at the curve on the four track Keystone Corridor in Rosemont, located about eleven miles west of Philadelphia. While normally pulled by GE Genesis P42DC diesel electric locomotive, on this run the "Pennsylvanian" was being powered by a AEM-7 electric locomotive (#924) as far as Harrisburg where it would have to change to diesel as the Norfolk Southern owned grade from Harrisburg to Pittsburgh is not electrified. The eastbound "Keystone Service" train is being pushed by a AEM-7 (#950) as well. Built, owned, and operated for more than a century by the Pennsylvania Railroad, since April 1, 1976, the grade (including all stations) between Philadelphia (30th Street Station) and Harrisburg (MP 105.2) has been owned and operated by Amtrak over which SEPTA also has operating rights for its Philadelphia regional rail commuter service between Zoo Interlocking (MP 1.9) and Cork Interlocking (MP 68.1) although by agreement between SEPTA and PennDOT, revenue service is prohibited west of Parkesburg (MP 44.2), the last station in Chester County. This portion of the grade was electrified by the PRR in 1915.