The configuration of southbound Metrolink train 100, which had a locomotive pushing passenger cars from the rear rather pulling them from the front, may have contributed to the severity of Wednesday's deadly derailment, according to transportation safety experts.
Trains pushed along the tracks generally have lighter, less sturdy passenger cars in front, which experts say have a greater chance of sustaining damage during a collision and are more likely to derail. The configuration also puts more people closer to the point of impact, placing a carful of passengers rather than an engine with the train's crew at the front.
The train that slammed into a Jeep Cherokee outside the Glendale station Wednesday was being pushed by a 140-ton locomotive and was led by a modified passenger car, known as a cab car, that weighed 56 tons.
"There is no question you are safer when the engine is pulling the train," said Loren Joplin, who worked as an accident and safety official for the Atchison, Topeka & Santa Fe Railway Co. in the 1970s. "For years, I have thought that using engines to push trains was going to end in a disaster. Had there been a locomotive on the front end, this would not have happened in Glendale."
Timothy L. Smith, who chairs the California legislative board of the Brotherhood of Locomotive Engineers and Trainmen, said union officials had been concerned about cab car safety for years.
Smith said the union had lodged formal written complaints about the issue with Amtrak and the Federal Railroad Administration, but nothing was done.
Not everyone, however, agrees that the placement of the train's engine is a significant safety issue.
Whether a locomotive is in the front or the rear of a train makes little difference in a crash, said George Elsmore, program manager at the California Public Utilities Commission's rail safety division.
Passenger cabs are reinforced to help withstand crashes, and both cabs and locomotives are outfitted with bumper-like devices meant to push cars and debris from the path of a train, "like a snow plow," he said.
Warren Flatau, a spokesman for Federal Railroad Administration, said "the evidence is not conclusive" on whether locomotives positioned in the rear are less safe than ones pulling from the front. But, he said, "there are clearly situations where, with on-track obstructions, a heavier locomotive might" be safer.
Although few studies have addressed the issue of train configuration, the Federal Railroad Administration conducted research in 1996 on what would happen if a train headed by a cab car were involved in a head-on collision with a train pulled by a locomotive. Researchers found that if the trains were going faster than 30 miles per hour, there would be substantial damage to the cab car, with "severe injury or fatality of the vehicle occupants."
The researchers also concluded that other types of accidents involving cab cars could have serious consequences.
"The concern with this type of train configuration is that the occupants of the relatively exposed cab car ... are vulnerable to serious injury or fatality in the event of a collision with either a road vehicle at a grade crossing or with another train," the Federal Railroad Administration said.
The practice of pushing trains has been around since at least the 1950s and is viewed by many transportation experts as the best way to run a commuter rail system, from a logistical and practical standpoint.
In such configurations, an engineer operates the train from controls in front of the cab car, where passengers also sit. The practice helps lines move trains more quickly and efficiently.
It is also less expensive because train operators don't have to buy additional locomotives or build turnarounds to move engines from one end of the train to the other.
In the Metrolink system, only Union Station is equipped with a turnaround system that allows train officials to move a locomotive from back to front, and the process is unwieldy and time-consuming, officials said.
Metrolink officials were unable to provide data Wednesday comparing crashes of trains being pulled with ones that occurred when trains were being pushed, but another accident along the same stretch of rail in January 2000 provided a contrast with Wednesday's collision.
In that case, a Metrolink train with the engine in front crashed into a tractor-trailer stranded on the tracks. The train did not derail and the crew walked away with only minor injuries.
Metrolink chief executive officer David Solow said Wednesday that the two accidents weren't necessarily comparable. In 2000, he said, the tractor-trailer was a long, horizontal mass across the track at the road intersection, but the SUV involved Wednesday was much smaller and may have been lodged on the rails.
"Most of the time, when we hit a car in a grade crossing, we win. The train has so much more weight, it either squashes the car or pushes it to the side," Solow said.
