WTNRR Bridge Replacement

The West Tennessee Railroad (WTNRR) consists of a main line that runs from South Fulton, KY to Corinth, MS and three branch lines.

The main line has more than 14,000 feet of bridges with almost 10,000 of that being timber trestle. With potential for overhead unit trains of 286,000 lb cars, in 2009 the railroad started looking at a program to accelerate the replacement of the mainline bridges. CSR Engineering worked with the railroad to develop a prioritized list of repairs and replacements. In January 2010 design on the first eight bridges began.

Utilizing a standard concrete trestle design, plans and specifications were prepared by March 2010. The design called for a four beam prestressed concrete superstructure supported by a precast concrete cap and steel pipe piling. The new bents were spaced such that construction of the substructure could be completed prior with minimal disturbance to train traffic. The superstructure would be changed out on weekends.

By utilizing a uniform design across all eight bridges, material procurement was simplified allowing the railroad to procure material in lieu of the contractor. This provided both a time and cost savings to the project. A ninth bridge replacement was added to the program and construction on all nine bridges was completed in the summer of 2011.

One bridge was identified as a possibility for filling in. CSR Engineering performed a hydraulic analysis of the basin and designed a solution using pipe arches. The railroad installed the pipe arches with railroad personnel in November 2010. Additionally, the floor beams on a through girder span were strengthened to meet the anticipated heavier loads of the unit trains.

CSR Engineering was responsible for the survey, hydraulic design, permitting, structural design, track design, material specification, shop inspection, and construction inspection while providing assistance with material procurement and the bidding process.