| Key Facts |
| Bridge Name | Facility Carried / Feature Intersected | Location | Structure Type | Construction Date / Builder or Contractor | |
|---|---|---|---|---|---|
|
Leet Street Bridge
| Leet Street Over Railroad (Norfolk Southern) | Leetsdale: Allegheny County, Pennsylvania | Metal Pinned Pratt Through Truss, Stationary | 1886 By: Morse Bridge Company of Youngstown, Ohio |
| Technical Facts |
| Rehabilitation Date | Main Span Length | Structure Length | Roadway Width | Main Spans | Approach Spans |
| 1904 | 105 Feet (32 Meters) | 109 Feet (33.2 Meters) | 19 Feet (5.8 Meters) | 1 | 0 |
This bridge was built in 1886 by Morse Bridge Company for the railroad at Lawrence Junction, PA and widened and relocated to this location in 1904. Because this truss widening occured so long ago and during a period where rivets and pin-connected truss bridges were still being built, the alteration is not readily apparent on the bridge nor does it diminish the historic significance. The alterations themselves are old enough to be historic.
This bridge features unusual design details, most noteworthy the corrugated built-up beams on the hip verticals and the bottom chords, a detail which adds to the historic significance of the bridge. The Historic Bridge Inventory refers to these as "Z" sections. This detail on the bridge is an uncommon type of built-up beam, that most often shows up on railroad bridges. In addition, the Leet Street Bridge does not display any of the design details commonly associated with the Morse Bridge Company. Some of the oldest Morse Bridge Company truss bridges had an uncommon detail in that they had no sway bracing but had heavy lateral bracing. They also tended to have a wide variety of decorative details. Another 1886 Morse Bridge Company bridge in Ohio does not display any unusual design details including the corrugated "Z" sections, and is nicely decorated. These facts, especially the railroad style corrugated "Z" sections may suggest that the Morse Bridge Company did not design the Leet Street Bridge but instead constructed the Leet Street Bridge according to railroad design plans.
Information and Findings From Pennsylvania's Historic Bridge InventoryDiscussion of Bridge The pin-connected, 1 span, 109' long, Pratt thru truss was built in 1886 by the Morse Bridge Co. It was originally part of Bridge No. 20 of the P.Y.& A. RR at Lawrence Junction, PA. The Pennsylvania RR moved the bridge to its present location as a road-carrying overpass in 1904. It was widened and reerected by the Pittsburgh Steel Construction Co. The truss bridge survives as a rare and complete example of an early metal truss bridge by the Morse Bridge Co. of Youngstown, OH complete with the unusual Z section in the hip panel floor beam hangers and bottom chords. It is historically and technologically significant. Discussion of Surrounding Area The bridge carries a 2 lane road and 1 sidewalk over 4 active Conrail tracks in Leetsdale borough. The resource includes only the Pratt thru truss bridge, not the steel stringer approach spans (BMS 02006502700000). The line is the former Pennsylvania RR main line the PHMC has determined to eligible. There is a PHMC-determined eligible Leetsdale Industrial Park historic district, but the bridge is not located in it. To the east is SR 65, and to the west is a residential area composed of altered, early-20th century houses. Bridge Considered Historic By Survey: Yes |
