Western Avenue

Henniker, New Hampshire

Client: Town of Henniker, New Hampshire


  • Construction Administration
  • Construction Observation
  • Design
  • Inspection
  • Materials Testing
  • Permitting

Project Summary

Hoyle, Tanner completed an in-depth inspection and load rating of the 300′ long, two span historic Pratt truss constructed in 1933 for the Henniker, New Hampshire. The inspection and rating included all gusset plates, and evaluating the replacement or rehabilitation of the bridge.

The inspection was accomplished over a two-week period using a “bridge tracker” to access components of the bridge from the water. The bridge was closed to vehicular traffic due to condition and limited live load capacity, therefore, access using an under-bridge vehicle was not possible. The top chords and portal bracing were accessed using ladders.

Due to the extremely poor condition of the structure, the bridge is being replaced. Hoyle, Tanner developed the bridge replacement design through the NHDOT Municipal Off-System Bridge Rehabilitation and Replacement (MOBRR) program, including the NEPA process, design, utility coordination, right-of-way coordination, hydraulic evaluations, geotechnical evaluations, cultural resource coordination and natural resource coordination. A programmatic Categorical Exclusion and individual Section 4(f) evaluation were also completed. The bridge is currently under construction being replaced with two new prefabricated, pre-engineered truss bridges founded on new cast-in-place substructures.

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