Zoo Junction is a

junction Junction may refer to: Arts and entertainment * ''Junction'' (film), a 2012 American film * Jjunction, a 2002 Indian film * Junction (album), a 1976 album by Andrew Cyrille * Junction (EP), by Basement Jaxx, 2002 * Junction (manga), or ''Hot ...

Amtrak The National Railroad Passenger Corporation, doing business as Amtrak () , is the national passenger railroad company of the United States. It operates inter-city rail service in 46 of the 48 contiguous U.S. States and nine cities in Canada ...

's Northeast Corridor in

Philadelphia Philadelphia, often called Philly, is the List of municipalities in Pennsylvania#Municipalities, largest city in the Commonwealth (U.S. state), Commonwealth of Pennsylvania, the List of United States cities by population, sixth-largest city i ...

Pennsylvania Pennsylvania (; ( Pennsylvania Dutch: )), officially the Commonwealth of Pennsylvania, is a state spanning the Mid-Atlantic, Northeastern, Appalachian, and Great Lakes regions of the United States. It borders Delaware to its southeast, ...

where the Northeast Corridor meets the

Keystone Corridor The Keystone Corridor is a 349-mile (562 km) railroad corridor between Philadelphia and Pittsburgh, Pennsylvania, that consists of two rail lines: Amtrak and SEPTA's Philadelphia-to-Harrisburg main line, which hosts SEPTA's Paoli/Thorndale ...

(ex- Pennsylvania Railroad main line).

History

Zoo Junction is a

flying junction A flying junction or flyover is a railway junction at which one or more diverging or converging tracks in a multiple-track route cross other tracks on the route by bridge to avoid conflict with other train movements. A more technical term is " g ...

, where multiple tracks cross one another by bridges to avoid conflict with other trains. In 1870, the Pennsylvania Railroad built the

Connecting Railway The Connecting Railway was a subsidiary of the Pennsylvania Railroad, incorporated to build a connection between the Philadelphia and Trenton Railroad and the PRR in the city of Philadelphia. Construction and assembly Connecting Railway The PRR c ...

from Frankford Junction to Zoo to bypass congested street running in Philadelphia. Instead of reaching the city directly from the north, the Connecting Railway turned west, crossed the

Schuylkill River The Schuylkill River ( , ) is a river running northwest to southeast in eastern Pennsylvania. The river was improved by navigations into the Schuylkill Canal, and several of its tributaries drain major parts of Pennsylvania's Coal Region. It f ...

on the Connecting Railway Bridge (a stone arch viaduct) and then turned south to join the PRR's Main Line at Mantua Junction. Mantua was a wye junction controlled by three manual signal boxes; there was also an engine house and the massive 37th Street Yard in the center of the wye. By 1888 the Mantua Junction was at capacity. In 1910 the PRR built two duck-under tunnels to allow trains to reach the Connecting Railway without blocking the Main Line and 37th Street Yard. The eastern 36th Street Tunnel also allowed grade-separated access to the Junction Railroad connecting to the

Philadelphia and Reading Railway The Reading Company ( ) was a Philadelphia-headquartered railroad that provided passenger and commercial rail transport in eastern Pennsylvania and neighboring states that operated from 1924 until its 1976 acquisition by Conrail. Commonly called ...

. Today, the tunnel only connects to the Northeast Corridor and is used by

SEPTA The Southeastern Pennsylvania Transportation Authority (SEPTA) is a regional public transportation authority that operates bus, rapid transit, commuter rail, light rail, and electric trolleybus services for nearly 4 million people in five c ...

, while the Junction Railroad now connects to the

West Philadelphia Elevated The West Philadelphia Elevated, also known as the High Line or Philadelphia High Line, is a railroad viaduct in the western part of Philadelphia, Pennsylvania. The structure spans the railway lines of 30th Street Station, parallel to the main tr ...

as part of the CSX

Harrisburg Subdivision The Harrisburg Subdivision is a railroad line owned by CSX Transportation in the U.S. state of Pennsylvania. The line is located in the city of Philadelphia, connecting Greenwich Yard and the Philadelphia Subdivision with the Trenton Subdivisi ...

. The western tunnel, called the New York-Pittsburgh Subway, allowed trains running from New York to Pittsburgh and west (such as the

Broadway Limited The ''Broadway Limited'' was a passenger train operated by the Pennsylvania Railroad (PRR) between New York City and Chicago. It operated from 1912 to 1995. It was the Pennsylvania's premier train, competing directly with the New York Central ...

) to bypass Broad Street station and a prolonged reverse move; such express trains would only stop in

North Philadelphia North Philadelphia, nicknamed North Philly, is a section of Philadelphia, Pennsylvania. It is immediately north of Center City. Though the full extent of the region is somewhat vague, "North Philadelphia" is regarded as everything north of either ...

. In 1935, the

interlocking In railway signalling, an interlocking is an arrangement of signal apparatus that prevents conflicting movements through an arrangement of tracks such as junctions or crossings. The signalling appliances and tracks are sometimes collectively re ...

reached its final form in conjunction with

electrification Electrification is the process of powering by electricity and, in many contexts, the introduction of such power by changing over from an earlier power source. The broad meaning of the term, such as in the history of technology, economic histor ...

and the construction of

30th Street Station 3 (three) is a number, numeral and digit. It is the natural number following 2 and preceding 4, and is the smallest odd prime number and the only prime preceding a square number. It has religious or cultural significance in many societie ...

and Suburban Station. Suburban commuter trains were routed to 30th Street's upper level towards Suburban, while intercity trains ran to the lower level. In the crescent-shaped pocket between the junction and the river was the

Philadelphia Zoo The Philadelphia Zoo, located in the Centennial District of Philadelphia on the west bank of the Schuylkill River, is the first true zoo in the United States. It was chartered by the Commonwealth of Pennsylvania on March 21, 1859, but its openin ...

, which gave the interlocking its name. The former Zoological Garden station was located next to the interlocking to serve visitors to the Zoo.

References

{{DEFAULTSORT:Zoo Junction Rail junctions in the United States Rail transportation in Philadelphia Amtrak Pennsylvania Railroad lines