Page "Electric locomotive" Paragraph 20

The first use of electrification on a mainline was on a four-mile stretch of the Baltimore Belt Line of the Baltimore and Ohio Railroad ( B & O ) in 1895.

This track connected the main portion of the B & O to the newly built line to New York and it required a series of tunnels around the edges of Baltimore's downtown.

Parallel tracks on the Pennsylvania Railroad had shown that coal smoke from steam locomotives would be a major operating issue, as well as a public nuisance.

Three Bo + Bo units were initially used, at the south end of the electrified section ; they coupled onto the entire train, locomotive and all and pulled it through the tunnels.

Railroad entrances to New York City required similar tunnels and the smoke problems were more acute there.

A collision in the Park Avenue tunnel in 1902 led the New York State legislature to outlaw the use of smoke-generating locomotives south of the Harlem River after 1 July 1908.

In response, electric locomotives began operation in 1904 on the New York Central Railroad.

In the 1930s, the Pennsylvania Railroad, which also had introduced electric locomotives because of the NYC regulation, electrified its entire territory east of Harrisburg, Pennsylvania.