(Bloomberg) -- The engineer operating an Amtrak train that derailed in Philadelphia last year pushed its throttle to full, increasing the train’s speed to 106 miles per hour, before entering a sharp curve, according to documents released by the National Transportation Safety Board Monday.
While not pinpointing a cause, the approximately 2,000 pages of documents rule out a number of potential contributing factors. Investigators have found no evidence of failures involved with the track, the locomotive and the signals that direct the engineer that could have caused the accident, a safety board official briefing reporters said on Monday.
The train’s engineer previously told investigators he can’t recall the moments immediately before the crash. According to a November interview made public on Monday, he described realizing the train was in a sharp curve and attempting emergency braking maneuvers.
The May 12 wreck, the deadliest Amtrak accident since 1999, cast a spotlight on the railroad’s safety. Eight of the train’s 238 passengers died, and more than 200 others were injured. Federal regulators ordered the U.S. passenger rail service to immediately improve safety on its Northeast Corridor route between Washington and Boston.
The documents add new details on the wreck, but offer little insight into how a healthy, fully qualified engineer might have missed multiple warnings and accelerated to more than twice the maximum speed for a curve.
The safety board will conclude the cause of the accident by this spring, according to the NTSB.
Amtrak said in a statement Monday it continues to cooperate fully with the NTSB. ‘‘The goal is for us to fully understand what happened and how we can prevent a similar tragedy from occurring in the future,” the company said in the statement.
The train’s engineer, Brandon Bostian, 31 at the time of the accident, applied full throttle seconds before the derailment, according to a factual report compiled by NTSB investigators.
Bostian, who suffered a blow to the forehead requiring multiple stitches and injuries to his legs, told investigators in May he couldn’t recall what happened prior to the crash. He said he couldn’t remember anything out of the ordinary and before the crash it had been a “fairly uneventful” trip.
“Unfortunately, the last memory I have on the way back is approaching and passing the platforms in North Philadelphia,” Bostian said in May. “I remember turning on the bell, and the next thing that I remember is when I came to my senses I was standing up in the locomotive cab after the accident.”
The Brotherhood of Locomotive Engineers and Trainmen, which represented Bostian, didn’t respond immediately to requests for comment.
As the train headed north, it followed all speed restrictions until after it passed through the North Philadelphia station at 60 miles (97 kilometers) per hour, according to the NTSB.
Less than 2 miles before the accident site, the engineer received a “clear” signal allowing him to increase to 80 miles an hour. He was supposed to then slow to 50 before hitting the curve where the accident occurred. Instead, the train continued accelerating and reached 106 miles per hour before the emergency brakes were applied moments before the derailment, according to the NTSB.
In this May 13, 2015 file photo, emergency personnel work at the scene of a deadly train derailment in Philadelphia. On Monday, Feb. 1, 2016, more than 160 documents related to the accident were released 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. (AP Photo/Patrick Semansky, File)
A black-box recorder on the train captured the throttle movement, which the NTSB attributed to Bostian. The engineer should have gotten visible and audible warnings about speed restrictions, an Amtrak foreman told investigators.
The NTSB has looked into the possibility that an object striking the locomotive on the northbound train from Washington distracted Bostian when the accident occurred. A grapefruit-sized fracture pattern was discovered in the windshield of the locomotive after the crash. The FBI didn’t find evidence that gunfire caused the damage.
Minutes before the accident, a dispatcher was talking on the radio to the engineer of the commuter train that was hit by an object and Bostian was able to hear them. An Amtrak dispatcher told NTSB investigators he was focused on the commuter train because the locomotive’s windshield was blown out and the engineer needed medical attention.
When asked if he was injured, the commuter-train engineer told the dispatcher he was “kind of dinged” with “glass all in my face.”
On Sunday, an object struck an Acela train near the crash scene, shattering a window on a passenger car, according to Associated Press. Amtrak officials say they haven’t concluded what object hit the train.
The NTSB noted in one report that Bostian said he recalled that the commuter train had been hit by a rock that shattered the engineer’s window, which he knew about because he was monitoring radio reports.
“I was a little bit concerned for my safety,” Bostian said according to NTSB. “There’s been so many times where I’ve had reports of rocks that I haven’t seen anything, that I felt like it was unlikely that it would impact me.”
Bostian said he knew a coworker who got glass in his eye after a collision with a tractor trailer. “I know how terrible that is,” he said.
Portions of the accident were captured by at least four video recorders, three from nearby surveillance cameras and another view from the front of the train. Based on still pictures from the locomotive’s view released by NTSB, the train entered the left-hand curve and tilted to the right until it rolled off the rails.
Emergency personnel help passengers at the scene of a train wreck, Tuesday, May 12, 2015, in Philadelphia. (AP Photo/ Joseph Kaczmarek)
Shower of sparks
The train left a shower of sparks as it tipped over and the train became disconnected from the high-voltage power wire above and its wheels skidded across the rails, according to two of the surveillance recordings.
Bostian said in an interview in November, six months after the crash, he had a “foggy memory” about feeling he was going too fast into a curve, and he responded by applying the brake. He then realized from feeling the momentum of the train “this is something very serious, and I need to bring down the train speed quickly.” Then he felt the engine tilting over.
“That’s when I realized that it wasn’t that the train was going somewhat fast around the curve,” Bostian told investigators. “The train was going significantly fast around the curve. And that’s when I put the train into emergency.”
Bostian said when he came to his senses following the derailment, he got his cellphone out of his bag, turned it on, and turned off airplane mode before dialing 911. The operator said the crash had already been reported. He was taken to the hospital and treated for a concussion and leg injuries.
Bostian said he was in good health, hadn’t taken any prescription medicine and felt well rested for the trip, according to NTSB reports. He tested negative for drugs and alcohol after the wreck.
In June, the NTSB determined that Bostian wasn’t using his mobile phone prior to the crash. The engineer didn’t violate Amtrak’s policy prohibiting distractions from personal electronics, the safety board said.
Bostian, who investigators said was “extremely cooperative,” gave up his phone’s password, which allowed the safety board to access data on the device without having to seek a subpoena, according to the NTSB. Investigators examined the phone’s operating system, which contains more than 400,000 files, according to the NTSB.
The NTSB also examined the design of the rail bed outside Philadelphia, which involves a series of sharp curves as trains make their way out of the city’s rail station going north.
The accident closed part of the busiest U.S. passenger-rail route for days, and Amtrak estimated it lost more than $9.2 million.
Amtrak installed more advanced automatic-braking technology known as positive train control, more widely throughout the Northeast Corridor. The NTSB has said such as system would have prevented the accident.
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