Boston Boston (), officially the City of Boston, is the state capital and most populous city of the Commonwealth of Massachusetts, as well as the cultural and financial center of the New England region of the United States. It is the 24th- mo ...

's central subway is the system of tunnels through which the

MBTA Green Line The Green Line is a light rail system run by the Massachusetts Bay Transportation Authority (MBTA) in the Boston, Massachusetts, metropolitan area. It is the oldest MBTA subway line, and with tunnel sections dating from 1897, the oldest subway ...

operates light rail transit (LRT or "trolley") service in the urban core of the city. The central subway comprises several tunnels built at different times, including the

Tremont Street subway The Tremont Street subway in Boston's MBTA subway system is the oldest subway tunnel in North America and the third oldest still in use worldwide to exclusively use electric traction (after the City and South London Railway in 1890, and the Bud ...

, the Boylston Street subway, and the

Huntington Avenue subway The E branch (also referred to as the Huntington Avenue branch, or formerly as the Arborway Line) is a light rail line in Boston, Cambridge, Medford, and Somerville, Massachusetts, operating as part of the Massachusetts Bay Transportation Aut ...

. Boston's subway operator, the

MBTA The Massachusetts Bay Transportation Authority (abbreviated MBTA and known colloquially as "the T") is the public agency responsible for operating most public transportation services in Greater Boston, Massachusetts. The MBTA transit network in ...

, sometimes also refers to the Red Line and Orange Line heavy rail tunnels as part of the central subway tunnel. In the early and mid twentieth century, the central subway was also known as the trolley subway, and was used for at least seven different trolley routes and with a variety of equipment. The original vehicles used were early single-unit electric trams with

trolley pole A trolley pole is a tapered cylindrical pole of wood or metal, used to transfer electricity from a "live" (electrified) overhead wire to the control and the electric traction motors of a tram or trolley bus. It is a type of current collector. Th ...

s to pick up the electric power from an overhead wire, which Boston had a decade of experience with. When the

opened in 1897, it handled over 280 trolleys per hour and took nearly 200 trolleys per hour off the congested Tremont Street.

Frank Sprague Frank Julian Sprague (July 25, 1857 in Milford, Connecticut – October 25, 1934) was an American inventor who contributed to the development of the electric motor, electric railways, and electric elevators. His contributions were especially i ...

introduced

electric multiple unit An electric multiple unit or EMU is a multiple-unit train consisting of self-propelled carriages using electricity as the motive power. An EMU requires no separate locomotive, as electric traction motors are incorporated within one or a numbe ...

(EMU) trains in Chicago, also in 1897, and those came to Boston a few years later, not in the trolley subway but in the new "elevated", the

Boston Elevated Railway The Boston Elevated Railway (BERy) was a streetcar and rapid transit railroad operated on, above, and below, the streets of Boston, Massachusetts and surrounding communities. Founded in 1894, it eventually acquired the West End Street Railwa ...

(BERy), which mostly served the West End. By 1901, Boston had the first EMU trains running underground, using some of the tracks and modified platforms of the Tremont Street subway. These heavy-rail lines evolved into the MBTA's Red, Orange, and Blue lines, which shared some of the central subway tunnels and stations with the light-rail Green Line. In 1908, a new Washington Street tunnel was opened, parallel to the Tremont Street subway from Haymarket station to

North Station North Station is a commuter rail and intercity rail terminal station in Boston, Massachusetts. It is served by four MBTA Commuter Rail lines – the Fitchburg Line, Haverhill Line, Lowell Line, and Newburyport/Rockport Line – and the Amtrak ...

, for the heavy-rail BERy traffic, restoring the Tremont Street subway to light-rail-only operation.

References

{{reflist Green Line (MBTA)