Dating to 1899, Bridge QG 40.81 is a double-track railroad bridge crossing the Mohawk River in Schenectady County, approximately 1.2 miles downstream from Hoffmans, New York. Under a task-order contract with CSX Transportation (CSXT), STV provided structural design for the replacement of the bridge’s aging deck plate girders, deck trusses and associated floor systems, along with construction observation services.
What challenges did STV address?
The project required replacing major structural components of a bridge dating to the late 19th century while retaining its existing substructure. Because the new deck plate girders would be supported by the existing substructure units, STV needed to evaluate whether the existing piling and pier shafts could adequately support the replacement structure.
What solutions did STV deliver?
STV designed the replacement of eight 61-foot deck plate girders and four 152-foot deck trusses and their associated floor systems. The replacement design uses four 61-foot and four 152-foot deck plate girder spans, with two girders per track. STV also designed new bolster blocks and pony bents for piers 1 and 5, new bolsters for piers 2 and 4, and track alignment improvements. The team performed a substructure analysis of the existing piling and pier shafts and provided construction observation services.
How does this project benefit the region?
The project renews critical infrastructure along an existing freight rail route while extending the usefulness of the bridge’s existing substructure. The replacement design modernizes key structural components supporting rail operations across the Mohawk River.
Key stats and accolades
- Bridge dates to 1899
- Double-track rail structure
- Eight 61-foot deck plate girders replaced
- Four 152-foot deck trusses replaced
