I'll have to see if I can dig up NPR the article, but Amtrak retired their AEM7's last year due to age and heavy mileage Average service life was in the range of 35 years. To put it in perspective the average service life of the GG1 was about 40 years. Not a bad record. Septa still has a few operational ones, but having been in commuter service with shorter distances between stop's I'm sure they are well past their prime even though they were purchased later than Amtrak's.
The replacement Siemens ACS-64 is same locomotive powers all non-Acela Amtrak electric trains reliably. At a 6,700 hp continuous rating and short term overload rating of 8,600 hp, these are pretty powerful motors.
