Whether operation of trains by locomotives pushing rather than pulling the cars is totally safe has come into question after the fatal Metro-North train wreck that killed 4 passengers and injured many others on December 1. The train consisted of 8 cars and a dual-mode diesel and electric locomotive, which was pushing the cars from the rear. According to reporting by Matt Flegenheimer and Patrick McGeehan in The New York Times (Dec. 2), rail-safety experts have at times questioned the performance of this type of train in the event of derailment, speculating that accidents were made more severe by the pushing force from the rear.
Of the commuter railroads in the New York area, Metro-North and the Long Island Rail Road use push-pull operation sparingly and mostly for trains the operate beyond the limits of electrification. These lines use all-electric “multiple-unit” equipment, in which there is no separate locomotive, for most services where electrification is available. The two railroads have been reequipping their electric car fleet in recent years.
In contrast, NJ Transit has chosen not to order new electric cars and increasingly is using locomotive-powered push-pull trains to provide service on all lines, even the electrified ones. Critics have said that NJT is even stalling on rehabilitating electric cars damaged in Superstorm Sandy.
The Metropolitan Transportation Authority, the parent of Metro-North, defended the use of push-pull equipment, saying that if the National Transportation Safety Board had any reservations, the railroads wouldn’t be allowed to use push-pull trains. Metro-North intends to install a “positive train control” system in which computers monitor train speed in advance of restrictions such as the sharp curve where the wreck occurred. The status of positive control system installation on NJ Transit is not clear, but NJT had been a leader in positive train control planning and has let several contracts over the past decade to begin installation of the system on its routes.
Read more about this (limited access) at http://www.nytimes.com/2013/12/02/nyregion/severity-of-derailment-revives-safety-concerns-about-pushed-trains.html