The train had:
1. Older engine, of class being retired mainly because they aren't reliable. Apparently, no "speed minder" equipment, just signals.
2. Zoo Junction north of Philly isn't far from Frankford, maybe 8 miles. 100 is 40 seconds per mile, not much time to have a brain fart or space attack. Or sneak off a text message. Or be distracted by a "fault" indicator.
Some reports have passengers "noticing" a brake application before the pile up. Normal braking and acceleration is almost never noticed by typical riders...that indicates to me the engineer had an "Oh, S$@%" and hit the emergency brakes too late.
