It appears as though some of the duties are of the turn-on-a-wheel variety, and others are what I learned as a split, or two-piece run, and the two-piece runs can affect concentration more than the turn-on-a-wheel. Somewhere, though, the business fad of the day, doing more with less, is going to run afoul of the reason economists speak of the factor-minimal production frontier.Disruptions can also involve unfamiliar rolling stock.
[Engineer Brandon] Bostian told the investigators that he primarily was assigned round-trips out of his New York crew base to Washington, D.C., on Acela Express trainsets in both directions. It was only after he “bumped” into different assignments during the previous month that he would “very very sporadically” draw an ACS-64.The ACS-64 is the latest electric locomotive assigned to the Northeast Corridor. The Acela power cars are pushing fifteen years old. The AEM-7 motors have been around for 35 years. The ACS-64 is more responsive to throttle changes than are the AEM-7s.
His most-recent Thursday through Tuesday work weeks in the month prior to the accident had involved running an Acela from New York to Washington and returning at the head of either train 90, the Palmetto, on the weekends, or Northeast Regional no. 198 on weekdays (the latter train has since been discontinued and combined with no. 90). Bostian told investigators that these New York-bound trains were generally assigned the older AEM-7 locomotives. That assignment was switched to a return on no. 188 as part of the shortening of layover times in Washington.
In response to a question, Bostian said, “I think it takes a long time to feel really familiar [with the new locomotive] but I felt comfortable with it.
Bostian explained the visual cues of the (clear) home signal at Shore interlocking and an overpass, as well as the sequence of speed limits leaving North Philadelphia: a 65 mph curve, then an 80 mph straightaway, then the 50 mph curve at Frankford Jct. On the second interview, he remembers incorrectly “targeting” 70 mph as the track speed for the straight stretch on that evening.Perhaps what would be a gentle tweak of the AEM-7 throttle to get to 80 is more like skinning back the ACS-64. The curve comes up on you a lot faster, and now you're in trouble. Watch for some additional speed testing of the locomotives.
“For any type speed increase, I gradually increase the throttle. I don’t slam it all the way open if I’m going slow. But if you’re going kind of fast, it’s OK to slam it open. But I typically accelerate in full throttle and then back off as I approach maximum speed.”
The last thing Bostian remembered before the derailment itself, however, is increasing the speed above 70 mph after he realized that the target on the straightaway should have been 80 mph.
Then at the curve, he recalled making a 10-pound brake pipe reduction. “I realized from the force of my body that this this is something very serious and I need to bring the train speed down quickly.” He then made a full service application, and finally an emergency application in quick succession.
Though not specifically referenced in questioning, Bostian’s testimony does establish a possible link between the ACS-64’s quick acceleration compared to AEM-7s, a fact revealed by another Amtrak engineer during a Trains cab ride aboard one of the new locomotives on June 2, 2014, and the relative inexperience of train no. 188’s engineer with the engine.