After the recent, tragic crash on the Harlem Line, the topic of third rail has become a talking point in the media. For those not exceptionally familiar with railroading (who have been frequenting the site as of late), electric trains can be powered by various methods, and most railroad systems picked one method of power for their road. Since Metro-North is made up of two historical railroad systems – the New York Central, and the New York, New Haven, and Hartford – you will not find just one method of powering electric trains here. One common type of power, which is seen on the New Haven Line, is the overhead catenary system. Wires above the train carry electricity, and trains have special “arms” called pantographs that reach up and connect with these wires.
Drawing of the bottom contact third rail invented by William Wilgus and Frank Sprague, from the patent documentation.
The other common method of train power, the third rail, comes in a few different “flavors,” but the concept on each is similar – an extra rail that conducts electricity is placed on the ground, and special shoes on the train connect with it and draw power. The New York City subway and Long Island Railroad, for example, use an over running third rail, where power is collected from the top of the third rail. This is the oldest type of third rail power. Metro-North, however, uses a method of under running third rail, which is also known as bottom contact third rail (or the Wilgus-Sprague system, for its inventors). As one would gather from the name, the power is collected from the bottom of the third rail. This method was especially invented for use in Grand Central Terminal, and was an improvement on the original by inventors William Wilgus (Chief Engineer of the New York Central) and Frank Sprague for safety. It is still used on the Harlem and Hudson Lines today, and is what was involved the recent crash.
Before I continue on, let’s break down some facts about the third rail in Valhalla, and about under running third rail:
- The railroad tracks running through the area in question have been in service since 1846.
- Under running third rail has been in service in the New York Metropolitan area since 1906.
- Third rail in the area in question was installed in 1983 when the Harlem Line was electrified to Southeast (then Brewster North).
- Over running third rail (like the LIRR uses) is the oldest type of third rail. Under-running third rail was developed later as a safer methodology, as it was less likely to electrocute a worker or trespasser, and better covered from rain, snow, and ice.
- The original NYC subway (IRT) used the older version of third rail because the under running variety had not been invented yet. The Long Island Rail Road followed suit when electrifying due to connections / planned connections with the subway.
- The same year that under running third rail was patented, the legislature of the State of Connecticut banned unprotected third rail technology after several people / animals were electrocuted. The whole concept of under running third rail was that the rail was protected, and thus considered far more safe.
- In modern usage, under running third rail seems appears overwhelmingly safer in comparison to over running. The subway and LIRR have had far more deaths in this manner – from numerous trackworkers, to people walking across the tracks, falling on the tracks, graffiti artists getting zapped, people trying to rescue dropped items, and even peeing on the third rail. Over the five year period from 2002 to 2006, one person was electrocuted by Metro-North’s third rail, while six were electrocuted by the Long Island Rail Road’s.
- The over running third rail used by the LIRR and subway are far more effected by rain, snow, and ice. Even a dropped umbrella onto the tracks managed to shut down the 7 line recently.
- Metro-North is not the only transit system to use under-running third rail. One line in Philadelphia uses it. Historically, a tunnel from Detroit to Windsor, Ontario used it, but that line was de-electrified. Transit systems in Vienna, Warsaw, Sao Paulo (and more) use under-running third rails.
- Few systems using under-running third rail means nothing about the soundness of the technology. It is only a legacy holdover to a country once comprised of many different railroad companies, each of which picked the technology best suited for them. The lines that comprise Metro-North were not even a unified system until 1969, which is why different modes of electrification are used across the system.
- While Chuck “Photo op” Schumer and Richard “Stolen Valor” Blumenthal would prefer to blame a third-rail design that has worked successfully for well over a hundred years, and is safer than the one used by our neighbors, the fact of the matter is that this accident would have 100% been prevented by better driver vigilance and abiding the sign “Do not stop on tracks.”