An ALC-42 and Two ACSES Locomotives on the Southwest Chief!

What is ACSES? The Advanced Civil Speed Enforcement System is a technology used by the eastern-based Amtrak, Septa, and other routes as an improved version of PTC. Implemented after the Frankfurt Junction Derailment in 2015. This technology allows these units to lead on the Northeast Corridor, more specifically the Pennsylvanian. A P42 without the tech cannot lead because it doesn’t have the required cab signaling and advanced PTC technology, which could be dangerous. In the beginning, the electric ACS-64s had to lead trains, acting as the brain until the certain locomotives got the necessary equipment. It is basically an advanced version of PTC and CTC. P42DCs 46, 85-134, and 145 are the only ones to have this tech, and this means they almost never leave the east. Let alone the NEC. They do occasionally venture out, but almost always trail.