The Cimarron Narrow Railroad Bridge is a historic steel truss bridge originally constructed in 1891. DJ&A developed a computer model and completed a structural analysis of the historic narrow-gauge bridge to aid in evaluating repair alternatives and developing a long-term maintenance plan for the structure. The project also included developing deck replacement options and cost estimates.

DJ&A conducted an initial site review of the bridge to assess the degree of damage to individual elements of the structure prior to preparing the computer model of the truss. A computer model was then developed and used to evaluate the significance of individual members in relation to the load carrying capacity of the structure. Based on these results, repair alternatives were developed for the truss. The analysis considered three separate loading scenarios.

To assist the park staff in determining the desired course of action for the bridge, DJ&A presented an explanation of the structural analysis, the results, and the repair recommendations to a Value Analysis team during the VA/CBA process. To complete this project, DJ&A will prepare detailed construction plans and specifications for the final repair alternative as determined through the VA/CBA process.

Key Services

  • Performed initial site visit and review to assess damage
  • Generated computer model of the bridge
  • Developed repair alternatives based on three load rating scenarios
  • Presented structural analysis and repair recommendations to NPS Value Analysis team
  • Prepared construction documents for the final repair alternatives

Value Added

DJ&A completed a laser scan of the historic bridge and generated a computer model of the structure to support the Park Service’s efforts to make repair recommendations.