Those Amtrak locos are over 20 years old. They are likely run for over 1,000 miles per day. If they are used for at least 250 days out of the year, then that's 250,000 miles/year. So, the locos have probably accumulated over 5 million miles of operation. Suppose you had a 20-year-old vehicle with 5 million miles on the clock, regardless of how well it was maintained, how faultless would you expect it to be in day-to-day use?