West Philadelphia Elevated

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Coordinates: 39 ° 57 ′ 43 "  N , 75 ° 11 ′ 4"  W.

West Philadelphia Elevated
West Philadelphia Elevated
The viaduct at the Amtrak Race Street Yard, 2012
use Railway bridge
Crossing of 30th Street Station railway facilities
place Philadelphia
Entertained by CSX Transportation
construction Scaffold pier viaduct and arch bridge
overall length 2481 m
Longest span 48 m
opening 1903
planner Pennsylvania Railroad
location
West Philadelphia Elevated (USA)
West Philadelphia Elevated

The West Philadelphia Elevated (also: High Line or Philadelphia High Line , German: Hochbahn Philadelphia-West ) is a railway viaduct in the west of Philadelphia in the US state of Pennsylvania . The 8,140-foot (2,481-meter) structure spans the railway systems of 30th Street Station parallel to the main line of tracks in a south-north direction. The 318.5 meter long brick arched north driveway is the longest brick bridge and possibly the longest brick structure in the United States.

The viaduct was built in 1903 by the Pennsylvania Railroad (PRR) and is now part of the Harrisburg subdivision of the railroad company CSX Transportation .

Emergence

The High Line was used to bypass the area around 30th Street Station.

At the turn of the century, the Pennsylvania Railroad (PRR) carried out a number of expansion measures on its route network. The aim of these was to improve the handling of freight traffic insofar as passenger and freight trains were to be run on separate tracks as far as possible. This should take into account the increased volume of traffic.

In the Philadelphia metropolitan area, the routing of the northeast corridor around Broad Street Station, the central passenger station, proved to be a bottleneck. The terminal station was on the east side of the Schuylkill and was connected to the main line running there via a track triangle on the west side of the river. In the area of ​​this node structure there was also a railway depot , various industrial plants and, from 1903, the West Philadelphia Station (German: Westbahnhof ) for through trains in north-south direction.

In addition, some railroad lines flowed in very close, on the north side the Philadelphia to Harrisburg Main Line to Harrisburg, the access to 37th Street Yard (freight yard 37th Street) and with the Junction Railroad the connecting line to the PRR competitor Reading . On the south side, the route to West Chester and the approach to the harbor branched off in the south of the city.

With the West Philadelphia Elevated, two through tracks for goods traffic in a north-south direction were to be led over these railway systems. This should enable freight trains coming from New York City or Harrisburg to travel south to Baltimore and Washington, DC, to bypass the railway facilities described. The Junction Railroad and the access to the port were also connected to the viaduct.

The construction was approved by the city council on December 24, 1902. The construction work was completed by the end of 1904.

course

The viaduct on the map to 30th Street Station.

The viaduct extends over a total length of 8140 feet (2481 meters) in a south-north direction and can be reached at both ends via heaped railway embankments. He describes a slight left curve, which is given by the course of the track around the 30th Street Station and ultimately the Schuylkill itself.

The southern ramp is between the tracks of the northeast corridor and the Schuylkill. There is the Arsenal Interlocking track triangle , which marks the convergence of two freight railways: the Harrisburg Subdivision joins from the east, coming from the port and has just crossed the Schuylkill on the Arsenal Bridge, and the connecting track from the northeast corridor comes from the southwest ; this also serves as an access from the Philadelphia subdivision of the CSX , which runs parallel to it . The viaduct begins directly behind the confluence of the two freight railways about 1.3 km as the crow flies southwest of 30th Street Station.

The High Line initially runs in a northeastern direction. It crosses the main tracks of the northeast corridor at an acute angle, then passes the University City regional train station immediately to the east and spans the road bridge on South Street behind it . After about 450 meters the viaduct swings north and successively crosses Walnut Street , Chestnut Street , Ludlow Street , Market Street and John F. Kennedy Boulevard . In this area, the route runs along 31st Street and adapts to the alignment of the street grid.

Then it goes about 170 meters to the west past the reception building of the 30th Street Station, whereby the upper platform level of the tower station is crossed at its extreme western end.

The ramp with the brick arches at the northern end.

Behind it begins a long, steady left curve that runs above the northern track field of 30th Street Station. About 320 meters north of crossing the Spring Garden Street bridge , the viaduct ends at a 450-meter ramp that ends at 34th Street bridge . This area is immediately southeast of Zoo Interlocking , the track triangle between the Northeast Corridor and the Philadelphia to Harrisburg Main Line.

The ramp at the north end leads down to the middle of the track. However, there have been no more track connections at this point since 1995; after about 750 meters the route leads out through a tunnel to the northwest and leads to the Trenton subdivision of the CSX, which in turn leads towards Jersey City .

function

The West Philadelphia Elevated was built by the Pennsylvania Railroad to accommodate freight traffic along the Northeast Corridor. Therefore, mainly freight railways were connected to the access roads next to the main line itself, the most important of which was the connection to the port at the southern end. The merger with the New York Central Railroad to form Penn Central and the takeover of freight traffic by Conrail after its bankruptcy initially did not change anything.

With the expansion of the northeast corridor for the Acela Express at the beginning of the 1990s, freight traffic was then almost completely shifted to the parallel routes of the former PRR competitors Baltimore and Ohio Railroad (B&O) and Reading , both of which belonged to CSX at the time . From there, however, there has always been no direct access to the port of Philadelphia, so that the trains could still only get there via the Junction Railroad and the High Line. The connections to the northeast corridor, however, were dismantled.

Instead, a new connecting curve to the Philadelphia subdivision of CSX was created at the south end, so that the viaduct together with the Junction Railroad now represents a parallel route to the former B&O in the city of Philadelphia, via which the port can also be approached.

Construction and appearance

The viaduct consists of two sections. The much larger part is made up of a steel construction with 136 fields and just as many pillars. The section north of Spring Garden Street, on the other hand, consists of an arch bridge with 30 brick arches, which extends halfway up to 34th Street. The viaduct has two tracks and was probably electrified around 1930. The western track has not been passable since at least the end of the 1990s.

steel construction

One of the steel supports.

The basic construction of the two steel sections consists of a series of support frames ("portals") along the route, on which a pair of longitudinal beams rests for each of the two tracks . The frames are estimated to be about 10 meters high and are alternately about 12 and 15 meters apart, with the pairs that are closer together being connected to steel scaffolding for stiffening with diagonal bars in the longitudinal and transverse directions .

Fields of different lengths along the route.

However, the local conditions made it necessary to deviate from this scheme in some places. Where, for example, no scaffolding was possible due to intersecting streets, a series of natural stone pillars was set instead. The associated fields are often excessively long and are then either designed as a steel framework construction below or - for greater clearance heights - as full-walled overhead beams. The longest such section has a span of 156 feet (47.55 m).

Several of these extra-long fields are related to the track system from 1903. However , their shape has changed completely since they were rebuilt in the course of the Philadelphia Improvements in the 1930s. Therefore, these fields no longer necessarily correspond to the local conditions, so that their arrangement sometimes appears quite arbitrary from today's perspective.

The crossing of the northeast corridor at the southern end.

Another exception is two crossings of the track field at the two outer ends. There, the tracks have crossed at a very acute angle since the described conversion of the railway systems, so that these steel scaffolding have since then been inclined to the viaduct and parallel to the tracks crossing below.

Arch bridge

Two of the brick arches.

The arched bridge at the northern end is 320 meters long and includes 30 arches with 30 feet (9.14 m) clear width each. For the masonry was contrary to the then usual conventions of the PRR to build bridges as far as possible in natural stone, brick used. This made this structure likely the longest brick bridge in the United States.

At that time, concrete , natural stone and brick were available for the construction of this section . Because concrete was considered unaesthetic and would probably have been too expensive, the decision was made in favor of masonry. Because natural stone could not have been procured quickly enough in that large quantity, brick was ultimately chosen, even though it was considerably more labor-intensive.

Overhead line

The portal masts typical of the PRR were used for the overhead lines, which carry traction power lines at the greatly extended upper ends of their supports. The masts are either mounted on the side of the steel supports of the viaduct or anchored to the ground next to them. Since the overhead line was dismantled in the 1980s, only the traction power lines have run along the High Line.

literature

  • Plowden, David: Bridges: The Spans of North America . WW Norton & Co., New York, 2002. (English)

Web links

Commons : 30th Street Station  - collection of pictures, videos and audio files

Individual evidence

  1. ↑ PRR CHRONOLOGY 1904 March 2005 Edition (PDF; 63 kB) . (English; accessed December 31, 2008)
  2. ↑ Mike Brotzman: Zoo Tower. ( Memento of August 7, 2008 in the Internet Archive ), The Signal Box, 2008.
  3. Jump up ↑ Southeast Corner - 31st and Chestnut - this April 2, 1930 image suggests similar work. The traction power line is already hanging, but the wires for the overhead line are still missing.
  4. ↑ According to this route diagram of the CSX , which dates from 1997/98, the route is already single-track at this time.
  5. ^ Plowden, David: Bridges: The Spans of North America . WW Norton & Co., New York 1974, p. 30.
  6. ↑ At least according to contemporary statements on the comparison of the construction costs of bridges using different materials, for example in Schuylkill River Railroad Bridge . Engineering Record 69, No. 7, February 14, 1914: 196