It is telling that Amtrak retired its HHP8000's earlier than the AEM7's (including the unrebuilt DC units). A mechanical person told me the HHP's averaged something like 85+ cents / mile to operate vs about 50 cents for the AEM7 AC's. (I don't recall what was included in those numbers.)

The Acela power cars (two of them per train) have the same characteristics as the retired units and you might recall problems with the cracked brake roters, the cracked brackets securing the yaw dampers and a third item for which I can't find an article - the decorative roof skirting was not properly secured to the carbody and posed a risk of falling off.

The newer trains which are to be manufactured by Alstom will be built to a new lighter standard and presumably will not need two locomotives in order to make schedule.


Brake Roter Problem

Yaw Damper Bracket Problems