WASHINGTON --The last thing Amtrak engineer Brandon Bostian remembers before last May's fatal crash in Philadelphia is pushing the throttle forward to pick up speed and then braking when he felt the train going too fast into a sharp curve, according to a transcript of his interview with federal accident investigators.
When he realized the train was about to derail, Bostian said he was holding tightly to the controls and thinking, "Well, this is it, I'm going over."
The transcript was among more than 2,200 pages of documents released Monday by the National Transportation Safety Board. The documents don't come to any conclusions on the cause of the crash but offer a glimpse into what investigators have learned thus far.
The documents are available on the NTSB's website at NTSB.gov
Among the most illuminating are two transcripts of interviews Bostian had with investigators, one immediately after the May 12 crash that killed eight people and injured nearly 200 others, and the second in November.
In the later interview, Bostian provided investigators with a vivid account of what he believes happened in the seconds before Train 188 left the tracks - a sharp contrast from his first interview, where he said he remembered little.
Bostian cautioned that there were "several gaps" in his recollection but that "a couple of prominent scenes" had come back to him since the previous interview.
PHOTOS: Onboard images of Amtrak 188 crash
The train's data recorder shows that at about 55 seconds - a mile and a half - before the Frankford Junction curve, one of the sharpest in Amtrak's Northeast Corridor, Bostian applied full throttle and held it there for about 30 seconds. The train reached a speed of about 95 mph.
He then slightly lowered the throttle for 2 seconds before returning to full throttle and holding it there for another 20 seconds. Three seconds before the train derailed, at a speed of 106 mph, Bostian applied the emergency brake.
That reduced the speed to 102 mph, but by then it was too late. Four of the train's seven cars and its locomotive derailed in a tangled heap.
The speed limit for the curve is 50 mph. The limit for the stretch of track prior to the curve is 80 mph.
Bostian, who suffered a head injury in the crash, said he remembers pushing the throttle to bring the train up to speed in an 80 mph zone after first thinking the limit there was 70 mph.
"Once I pushed the throttle forward in an attempt to bring the train up to 80 miles an hour, I don't have any other memories until after the train was already in the curve," Bostian said in the November interview.
The engineer told investigators that his practice for accelerating trains is to "gradually increase the throttle. I don't slam it all the way open when I'm going slow. But if you're going kind of fast, it's okay to slam it open. But I typically accelerate in full throttle and then back off as I approach the maximum speed."
It's difficult at night to see where the curve starts but there are visual cues that it's coming up, Bostian told investigators, including track signals and a nearby elevated subway bridge where he said he would normally start braking to bring the train down to 50 mph. He said he did not look for speed restriction signs because they are sometimes missing or wrong.
"As that track curves to the left, it kind of, you're looking into somewhat of a black abyss," Bostian said.
An NTSB official described Bostian as "extremely cooperative" with investigators. The official, who wasn't authorized to speak publicly, talked to reporters on condition of anonymity shortly before the board released the documents.
NTSB has wrapped up its investigative phase into the accident. Next, investigators will analyze the evidence, prepare a report on the probable cause of the derailment and make safety recommendations. A draft report is expected to be delivered to board members in a meeting not yet scheduled, but that will likely happen around the May 12 anniversary of the crash.
Bostian provided his cellphone to investigators, who say there's no indication he was using it while operating the train.
Other avenues of investigation have also turned up dry holes, according to previous statements by investigators. The data recorder shows the train's top-of-the-line new Siemens engine was functioning normally. No anomalies were found in the tracks or signal boxes. There was no vehicle or object on the tracks. Toxicology tests of Bostian found no drugs or alcohol.
The train's assistant conductor said that before the crash he heard Bostian on his radio say the train had been hit by something, but a transcript of radio communications that night doesn't show Bostian saying the train had been hit.
The operator of a commuter train in the same areas reported shortly before the crash that a rock had shattered his windshield and he had glass in his face.
In one interview, Bostian noted that the Southeastern Pennsylvania Transportation Authority engineer indicated there may also have been shots fired. "I was a little bit concerned for my safety," he said.
Trains operating in the Northeast corridor are frequent targets of rock-throwing vandals. Other trains in the vicinity of Frankford Junction reported being hit by rocks that evening not long before the derailment. A small dent was found in the windshield of Amtrak 188's locomotive.
Bostian has been suspended without pay since the crash. A letter from Amtrak in the NTSB files shows he was suspended for speeding the night of the crash.