Mount Washington Transit Tunnel is an important public transportation link in Pittsburgh, Pennsylvania

Pennsylvania

The Commonwealth of Pennsylvania is a U.S. state that is located in the Northeastern and Mid-Atlantic regions of the United States. The state borders Delaware and Maryland to the south, West Virginia to the southwest, Ohio to the west, New York and Ontario, Canada, to the north, and New Jersey to...

, United States

United States

The United States of America is a federal constitutional republic comprising fifty states and a federal district...

. The approximately 3500 feet (1,066.8 m)Middleton, William D. (1967). The Time of the Trolley, p. 195. Milwaukee, WI (US): Kalmbach Publishing Co. LCCN 67-20155. tunnel connects Station Square

Station Square (PAT station)

Station Square is a Transit station on the Port Authority of Allegheny County's light rail network. It is the last Transit station on the south side of the Monongahela River.This station is named for the nearby mixed-use development Station Square...

 to South Hills Junction

South Hills Junction (PAT station)

South Hills Junction is a station on the Port Authority of Allegheny County's light rail network. This station served as the original "merge point" of the inbound Beechview and Overbrook branches of the light rail system, just before the run under Mount Washington through the Mount Washington...

, and is used only by Pittsburgh Light Rail

Pittsburgh Light Rail

The Pittsburgh Light Rail is a light rail system in Pittsburgh, Pennsylvania; it functions as a subway in Downtown Pittsburgh and largely as an at-grade light rail service in the suburbs. The system is owned and operated by the Port Authority of Allegheny County...

 cars and buses

Transit bus

A transit bus , also known as a commuter bus, city bus, or public bus, is a bus used for short-distance public transport purposes...

 of the Port Authority of Allegheny County

Port Authority of Allegheny County

Port Authority of Allegheny County is the second-largest public transit agency in Pennsylvania and the 11th-largest in the United States. When considering that its service area is the 20th largest in the U.S...

.

History

The tunnel was built by Booth and Flinn

Booth and Flinn

Booth and Flinn was one of the largest American general contracting companies of its era. It was established and headquartered in Pittsburgh, Pennsylvania, United States....

, as a replacement for the Pittsburgh and Castle Shannon Tunnel

Pittsburgh and Castle Shannon Tunnel

The Pittsburgh and Castle Shannon Tunnel, also known as the Mount Washington Coal Tunnel, was a narrow gauge railway tunnel under Mt. Washington.-History:It was originally begun as a coal mine in 1825 by Jacob Beltzhoover....

, but at a lower elevation. Excavation was started October 6, 1902, and the tunnel was officially opened December 1, 1904, for use by trolleys/streetcars

Tram

A tram is a passenger rail vehicle which runs on tracks along public urban streets and also sometimes on separate rights of way. It may also run between cities and/or towns , and/or partially grade separated even in the cities...

 only. Originally, steam powered trains ran through the tunnel, to be replaced by the first electric cars in 1909. It took over the transportation functions of the Castle Shannon Railway tunnel, which was originally a coal mine, but later used as a tunnel to transport coal, and later passengers, under Mt. Washington. Although this tunnel was closed to passengers in 1880, the urban legend

Urban legend

An urban legend, urban myth, urban tale, or contemporary legend, is a form of modern folklore consisting of stories that may or may not have been believed by their tellers to be true...

 persists that the Mt. Washington Transit Tunnel was originally a coal mine.

The tunnel was upgraded to allow for joint use by bus and trolley traffic in 1973, with several changes since.

Accidents

Two spectacular runaway accidents are associated with the tunnel, which is on a steep gradient averaging over 6 percent, and curves as the north portal is reached.

On December 24, 1917, Knoxville service car 4236 ran away downhill after becoming detached from the wire and derailed and overturned on the curve into Carson Street

South Shore (Pittsburgh)

The South Shore is a neighborhood in Pittsburgh, Pennsylvania South Side. The South Shore consists of the area surrounding Carson Street, from the West End Bridge to the Liberty Bridge.The South Shore is an industrial neighborhood, home to several warehouses...

. The car slid on its side until hitting a telegraph pole which ripped the roof off. Twenty-one people were killed and 80 were injured; the claims from the accident sent Pittsburgh Railways

Pittsburgh Railways

Pittsburgh Railways was one of the predecessors of the Port Authority of Allegheny County. It had 666 PCC cars, the third largest fleet in North America. It had 68 street car routes, of which only three are used by the Port Authority as light rail routes...

 into receivership

Receivership

In law, receivership is the situation in which an institution or enterprise is being held by a receiver, a person "placed in the custodial responsibility for the property of others, including tangible and intangible assets and rights." The receivership remedy is an equitable remedy that emerged in...

.

On October 29, 1987, a 1700-series all-electric PCC car began to exceed the tunnel's speed limit as it entered the south portal after departing South Hills Junction

South Hills Junction (PAT station)

South Hills Junction is a station on the Port Authority of Allegheny County's light rail network. This station served as the original "merge point" of the inbound Beechview and Overbrook branches of the light rail system, just before the run under Mount Washington through the Mount Washington...

. The operator, realizing the car could neither stop nor take the sharp curve from the transitway to the Panhandle Bridge

Panhandle Bridge

The Panhandle Bridge carries two rail lines of the Port Authority "T" line across the Monongahela River in Pittsburgh, Pennsylvania. The name comes from Pennsylvania Railroad subsidiary Pittsburgh, Cincinnati, Chicago and St...

 ramp, ordered all the passengers to move to the back, and radioed the PAT central dispatcher to clear Station Square

Station Square

Station Square is a indoor and outdoor shopping, dining and entertainment complex located in the South Shore neighborhood of Pittsburgh, Pennsylvania, United States....

. The car left the rails and took Smithfield Street

Smithfield Street Bridge

The Smithfield Street Bridge is a lenticular truss bridge crossing the Monongahela River in Pittsburgh, Pennsylvania, USA.The bridge was designed by Gustav Lindenthal, the engineer who later designed the Hell Gate Bridge. The bridge was built between 1881–83, opening for traffic on March 19, 1883....

 instead (the trolleys' original route downtown, until 1985), crossing Carson Street, sideswiping a PAT bus and a truck, and knocking out a fire hydrant. Miraculously, the car stayed on its wheels, and finally stopped next to the Pittsburgh History & Landmarks Foundation

Pittsburgh History and Landmarks Foundation

The Pittsburgh History & Landmarks Foundation is a nonprofit organization founded in 1964 to support the preservation of historic buildings and neighborhoods in Pittsburgh, Pennsylvania, USA....

, the former Pittsburgh and Lake Erie station building at Station Square. Thirty-seven people were injured, four seriously, but there were no fatalities. All three braking systems on the car had failed: the drum

Drum brake

A drum brake is a brake in which the friction is caused by a set of shoes or pads that press against a rotating drum-shaped part called a brake drum....

, dynamic

Dynamic braking

Dynamic braking is the use of the electric traction motors of a railroad vehicle as generators when slowing the Locomotive. It is termed rheostatic if the generated electrical power is dissipated as heat in brake grid resistors, and regenerative if the power is returned to the supply line...

, and magnetic rail brakes. Most of the 1700 series cars were found to have electrical defects, prompting PAT to retire all of their remaining PCC's that had not been rebuilt as 4000 series cars

Port Authority 4000 Series PCC

The 4000 Series PCC was a streetcar used by the Port Authority of Allegheny County. The PCC streetcar was designed by the Presidents' Conference Committee, a group of transit operators in the United States and Canada. The 4000's were a series of cars completely rebuilt from cars built in 1949 by...

. Consequently, PAT was left with a shortage of cars, which contributed to the closure of the Overbrook line in 1993.