Railroad electrification in the United States began at the turn of the 20th century and comprised many different systems in many different geographical areas, few of which were connected. Despite this situation, these systems shared a small number of common reasons for electrification.
Most of the systems discussed in this article are either no longer electrified, or are now part of the Northeast Corridor and Keystone Corridor systems used by Amtrak and several commuter rail lines. A few isolated systems operate exclusively for hauling coal from mines to power plants. Most mass transit, streetcar, and interurban systems electrified very early (many from the beginning) but are not within the scope of this article.
The Association of American Railroads opposes electrification due to its high capital costs.
Impetus for electrification
Laws banning steam locomotives (smoke abatement) A number of municipalities passed laws in the early part of the 20th century forbidding steam locomotives from operating within city limits, after some bad accidents caused by the awful conditions of visibility in smoke and steam-filled tunnels and cuttings. The most prominent of these laws was for New York City in 1903 (effective 1908).
An extensive study was also undertaken in Chicago of the problems of smoke and the feasibility of electrification as a solution.
Long tunnels
Long, deep tunnels provide poor ventilation for steam locomotives, to the point where crews had to wear oxygen masks to avoid asphyxiation. The ventilation problem also limited the frequency of trains through these tunnels. The Cascade Tunnel is a good example. Also see the proposed North–South Rail Link.
Mountains
The electric locomotive has many advantages in mountainous terrain, including better adhesion, greater power at low speeds, no requirements for fueling or watering, and regenerative braking. The planned California High-Speed Rail system, for example requires electrification to achieve acceptable speeds through the Tehachapi Mountains.
Traffic density
Extremely high-traffic lines can readily recoup the high capital investment of electrification by the savings accrued during operation. The savings typically result from improved utilization of trains, and lower maintenance costs.
Short-distance commuter operations
Suburban commuter trains are an ideal subject for electrification since electric multiple units possess rapid acceleration, fast braking (sometimes regenerative braking) and the ability to change direction without running a locomotive around. It also reduces diesel locomotive emissions in relatively high-density areas.
Freight operations
Heavy freight trains are ideally suited to electric traction due to the greater pulling power of an electric locomotive.
Overview of electrification in the U.S. Electrification in the US reached its maximum of in the late 1930s.
By 1973, it was down to (Class I railroads) with the top 3 being: Penn Central , Milwaukee Road , Long Island Rail Road .
In 2013, the only electrified lines hauling freight by electricity were three short line coal haulers (mine to power plant) and one switching railroad in Iowa. The total electrified route length of these four railroads is . While some freight trains run on parts of the electrified Northeast Corridor and on part of the adjacent Keystone Corridor, these freight trains use diesel locomotives for traction. The total electrified route length of these two corridors is . Diesel-powered freight runs similarly operate over the South Shore Line and the San Diego Trolley light rail system.
History of electrification projects in the United States
Smoke abatement
Cleveland Union Terminals Co.
In June 1929 this railroad switched from steam to electric operation on a route between Collinwood and Linndale in Ohio. A overhead system was used. This change of operation was for smoke abatement. Electric operation ceased in 1953.
New York Central Railroad (Hudson and Harlem Divisions)
The New York Central electrified a section of its main line Hudson Division route in 1913 from New York City (Grand Central Terminal) to Harmon (now Croton-Harmon), where it changed to at first steam, then diesel power. The Harlem Division in Westchester County, New York was also electrified to North White Plains. Metro-North Railroad, the successor to New York Central's commuter operations, continues to use these lines, and extended the Harlem Line electrification to Southeast in 1984. The lines are electrified at with under-running third rail.