Zoo Junction is a junction on

Amtrak The National Railroad Passenger Corporation, Trade name, doing business as Amtrak (; ), is the national Passenger train, passenger railroad company of the United States. It operates intercity rail service in 46 of the 48 contiguous United Stat ...

Northeast Corridor The Northeast Corridor (NEC) is an electrified railroad line in the Northeast megalopolis of the United States. Owned primarily by Amtrak, it runs from Boston in the north to Washington, D.C., in the south, with major stops in Providence, Rhod ...

Philadelphia Philadelphia ( ), colloquially referred to as Philly, is the List of municipalities in Pennsylvania, most populous city in the U.S. state of Pennsylvania and the List of United States cities by population, sixth-most populous city in the Unit ...

Pennsylvania Pennsylvania, officially the Commonwealth of Pennsylvania, is a U.S. state, state spanning the Mid-Atlantic (United States), Mid-Atlantic, Northeastern United States, Northeastern, Appalachian, and Great Lakes region, Great Lakes regions o ...

, where the

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, Philadelphia-to-Harrisburg main li ...

, previously known as the

Pennsylvania Railroad The Pennsylvania Railroad ( reporting mark PRR), legal name as the Pennsylvania Railroad Company, also known as the "Pennsy," was an American Class I railroad that was established in 1846 and headquartered in Philadelphia, Pennsylvania. At its ...

's Main Line.

History

19th century

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 "gr ...

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

built the Connecting Railway 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 in eastern Pennsylvania. It flows for U.S. Geological Survey. National Hydrography Dataset high-resolution flowline dataThe National Map(). accessed April 1, 2011. from Pottsville, Pennsylvania, Pottsville ...

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.

20th and 21st centuries

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 rail transport, railroad that provided passenger and freight transport in eastern Pennsylvania and neighboring states from 1924 until its acquisition by Conrail in 1976. Commonly called th ...

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

SEPTA SEPTA, the Southeastern Pennsylvania Transportation Authority, is a regional public transportation authority that operates bus, rapid transit, commuter rail, light rail, and electric trolleybus services for nearly four million people througho ...

, while the Junction Railroad now connects to the West Philadelphia Elevated as part of the CSX Harrisburg Subdivision. The western tunnel, called the New York-Pittsburgh Subway, allowed trains running from

New York City New York, often called New York City (NYC), is the most populous city in the United States, located at the southern tip of New York State on one of the world's largest natural harbors. The city comprises five boroughs, each coextensive w ...

Pittsburgh Pittsburgh ( ) is a city in Allegheny County, Pennsylvania, United States, and its county seat. It is the List of municipalities in Pennsylvania#Municipalities, second-most populous city in Pennsylvania (after Philadelphia) and the List of Un ...

and west to bypass Broad Street station. Such express trains only stopped in

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

. 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. In North America, a set of signalling appliances and tracks inte ...

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. In the context of history of technology and economic development, electrification refe ...

and the construction of

30th Street Station 30th Street Station, officially William H. Gray III 30th Street Station, is a major intermodal passenger transport, intermodal transit station in Philadelphia, Pennsylvania, United States. The station opened in 1933 as Pennsylvania Station– ...

and

Suburban Station Suburban Station is an Art Deco office building and underground commuter rail station in Penn Center in Philadelphia. Its official SEPTA address is 16th Street and JFK Boulevard. The station is owned and operated by SEPTA and is one of the t ...

. 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 is the

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

, which gave the interlocking its name. The former

Zoological Garden station Zoological Garden station was a railroad station in Philadelphia, Pennsylvania. It was located at 34th Street and Girard Avenue, it served the Philadelphia Zoo and nearby areas. Built by the Pennsylvania Railroad, it closed in 1902 as the railr ...

was located next to the interlocking to serve visitors to the Zoo.

References

{{DEFAULTSORT:Zoo Junction Northeast Corridor Philadelphia to Harrisburg Main Line Rail junctions in the United States Rail transportation in Philadelphia