Workshop of the World

stories of industry in & around Philadelphia

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Delair Bridge, 1896
Pennsylvania Railroad (now Conrail) over the Delaware River

Jack J. Steelman, Workshop of the World (Oliver Evans Press, 1990).

The Pennsylvania and the Reading Railroads' first conquest of the lucrative New Jersey Shore trade began with the introduction of ferry service between Philadelphia and Camden. Patrons riding the Pennsylvania received a short ferry ride, but the train trip to the Shore was long; conversely, patrons riding the Reading had a longer ferry ride, but the train trip to the Shore was short.
 
It was the Pennsylvania Railroad, with its large financial structure and imposing Broad Street Terminal, which first crossed the Delaware by bridge. The site chosen was in Bridesburg, far above the river traffic at the pier in Center City and Camden. The line branched off the main line of the Pennsylvania (the New York-Philadelphia route) at Frankford Junction and traveled as an elevated structure up to. the river.
1 From there it traveled over two fixed steel spans to a steam-powered, gear-driven horizontal revolving span at a point greater than halfway across the river. After crossing the revolving span, the line travelled across another fixed steel span and then entered New Jersey. It met up with the Camden-Atlantic City Pennsylvania Railroad line at Haddonfield.

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"Pivot bearing of swing span" Joseph Elliott (1999). HAER
 
When U.S. Steel built its Fairless Hills plant near Bristol, Pennsylvania, the U.S. Army Corps of Engineers widened and deepened the Delaware River channel to permit movement of heavy barges. They also relocated the channel at the Delair Bridge, forcing the construction of a new, lift-type draw span and the permanent securing of the revolving span.

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"Overview from southeast" Joseph Elliott (1999). HAER
 
The technique of replacing a fixed span with a new lift-type draw span was an ingenious combination of bridge engineering, marine transport, and the weather. To remove the fixed span, an elevated framework was constructed on a barge that was moved to the Philadelphia side of the river. The framework was constructed to be similar in height to the fixed span of the bridge. At the time of the month when the low tide was at its very lowest, the barge was floated into place, directly beneath pre-engineered points on the fixed span. As the tide rose to its very highest, the pins anchoring the span were released and the span rose off its abutments, ready to be tugged upstream.
2

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"Looking west over top of vertical lift span" Joseph Elliott (1999). HAER
 
Likewise, the new lift-type draw span was assembled on a similar barge, positioned on the Philadelphia side upstream of the bridge. It was floated into place during the highest tide and allowed to settle as the tide ebbed. Once the span was secured, high towers with counterweights and sheaves were installed.
3 Presently, the bridge is used by freight traffic and now, more recently, by the "Gamblers Express" passenger service to Atlantic City.

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"Hoist mechanism for vertical lift span" Joseph Elliott (1999). HAER

1   Being elevated, the line had bridges not only at existing streets but at locations where bridges might be anticipated at future dates.
2   This information drawn from the personal recollection, notes, and photos taken by the author.
3   Notes of the Author.


Update May 2007 (by Joel Spivak):
Still in place.