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picture of bridge

View north along 33rd St from Mullberry Wy near Railroad St

More detail photos


Pittsburgh Junction Railroad Trestle above 33rd St


USGS 7.5" Topo Quad - UTM Coordinates:
Pittsburgh East - Zone 17; 0587 4479

CSX (former Pittsburgh Junction Railroad, Baltimore & Ohio Railroad)

-- near Herron Av bridge
-- Allegheny River bridge at Herr's Island (Washington's Landing)

(north to south)
Trestle above 33rd Street from left bank of Allegheny River to Liberty Av
-- Railroad St, Allegheny Valley Railroad
-- Spruce Wy
-- Smallman St
-- Mullberry Wy (western section; alley offset at 33rd St due to street grid change)
-- Mullberry Wy (eastern section)
-- Penn Av
-- Spring Wy
Trestle ends, remainder of structure is simple spans
-- Liberty Av

Primarily metal plate girder deck spans on plate girder bents and trussed bents
Spans over roadways are pony type
Spur to 36th St Yard is trussed wooden trestle

Collection of spans ranging from 30 ft to 100 ft est:
6 simple spans at Liberty Av and south
37 spans above 33rd St from Liberty Av to wye near Allegheny River;
Mainline continues on 5 spans to southern river pier of Allegheny River bridge;
Wye leads to wooden trestle descending to 36th St Yard which extended to 40th St

TOTAL LENGTH (including longest elevated ramp):
6 spans over and south of Liberty Av: 360 ft est total
Trestle above 33rd St, Liberty Av to wye: 1,794 ft
From wye to river pier: 257 ft est
Wye trestle to 36th St Yard: 7 metal spans, 360 ft est total; 74 wooden spans, 592 ft est total


c1884 Pittsburgh Junction Railroad
acquired 1902 by Baltimore & Ohio RR
reconstructed and elevated further, c1923

Pittsburgh Junction Railroad opened its line September 1884. The line ran between the Pittsburgh & Connellsville RR at Laughlin Junction (Second Av near Monongahela River and Four Mile Run) and the Pittsburgh & Western Railroad at Willow Grove (right bank of Allegheny River near Herr's Island). All of the companies were acquired by the Baltimore & Ohio Railroad by 1902; they were later merged into CSX.

There were two ordinances approved to authorize the route of the railroad. They were identical from the Monngahela River through Junction Hollow and the Neville Street tunnel. One would have included another tunnel to 35th Street. The route as constructed was described in the July 1883 ordinance as follows: "...crossing Sassafras and Forfar streets to a point at the intersection of Ewing and Thirty-third streets, thence crossing Liberty avenue and following Thirty-third street, and crossing Penn avenue, Mullberry, (formerly Lafayette), and Smallman streets, and any intervening street or alley above grade to the Allegheny River...thence by a branch westerly to Eleven street, and easterly to Negley's run...Provided, That the crossings of said streets shall be by substantial iron structures, to be approved by the city engineer, and giving not less than fifteen feet of clear height: And provided, That the said road, so far as the same runs along Thrity-third street north of Liberty avenue, shall be supported upon a substantial iron structure, to be approved by the city engineer, and of the clear height of fifteen feet above the grade of said street, and of the full width of the cartway of said street, and so constructed that said structure shall not, in any manner, interfere with public travel upon said street."

With the city's annexations of surrounding areas, many duplicate street names had to be resolved. Thirty-Third St had previously been Boundary St, having once been the eastern extent of Bayardstown. The Strip District was carved by various speculators into a series of gridded towns, including Bayardstown from 20th to 33rd streets. The street grid was reoriented to follow the river as it crossed into Croghansville and then into Lawrenceville approaching 40th St. Bayardstown became Pittsburgh's Fifth Ward in 1837; Lawrenceville was once of numerous areas added in 1868. Perhaps this seam in the street layout was seen as a logical place to allow the railroad to cross. The Pittsburgh Junction Railroad had been routed through two deep valleys which formed natural and political borders; Boundary St is still found in pieces near Bloomfield and Oakland.

from Railroads - Part of the Pittsburgh Plan:
"Thirty-Sixth Street Yard is located on the south bank of the Allegheny River, at 36th Street. The yard is principally used to collect cars to and from local industries; and, to some extent, for the storage of cars. The yard is of considerable importance as it serves, through the track paralleling the river, the thickly settled industrial district between 9th and 43rd Streets. Northbound trains enter the yard by direct movement off the mainline. Southbound trains enter by a reverse movement after crossing the Pittsburgh Junction Railroad bridge."

"...several years ago the Company raised its elevated structure on 33rd Street and the bridge across the Allegheny River to eliminate a dangerous grade crossing at Liberty Avenue."

The City of Pittsburgh Municipal Year Book [1912?] reported elevating the Pgh Jct RR over Liberty Avenue would have a "total estimated cost of $645,978 (to be) divided as follows: City of Pittsburgh, $152,342.50; Pittsburgh Railways Company, $100,000; and the Pittsburgh Junction Railroad the balance, amounting to $393,635.50."

Kobus notes the B&O, after spanning the river at 33rd St, originally crossed the West Penn (PRR) at grade at Willow Grove (right bank of Allegheny River near Herr's Island). The B&O tracks were raised and separated from the PRR by 1923.


This location is unusual for Pittsburgh. Many other cities have elevated railroads; this is perhaps the only structure of its kind here. Only the portion of the Blvd of the Allies above Second St is similar in appearance. The wooden trestle connecting to the 36th Street Yard is also unique in the Pittsburgh area. There are few other wooden bridges here, and none of the others approach the size of this one.


1906 Hopkins plat map shows the location of the filled back channel that separated Wainwright's Island from the shore. It is noted as "Old Channel Property of City of Pittsburgh." The Pgh Jct spur to the 36th St Yard runs nearly down the centerline of the old island. The downstream end of the island was less than 100 feet up from 33rd St. By 35th the island had widened so that the old channel was half the distance between the current shore and the Allegheny Valley Railroad -- with the channel itself being about one-fifth that total in width. A bit less than half of the Pgh Jct 36th St Yard was built on the filled channel.

The 1872 map predates the construction of the Pgh Jct RR, but shows the buildings of Union Iron MIlls - Carnegie, Kloman & Co on the site of the present oil terminal at 33rd St. The 1886 map shows the Pgh Jct RR, but the 36th St Yard and spur had not yet been constructed.


field check; "Railroads - A Part of the Pittsburgh Plan" [1923]; "Municipal Year Book / City of Pittsburgh" [1912?]; "The Pennsy in the Steel City," Kobus & Consoli

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Introduction -- Nearby Structures

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Last modified: 19-Apr-2005

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