Fort Niagara Entrance Trestle Structural Rehabilitation

The Niagara Regional Office of the New York State Office of Parks, Recreation, and Historic Preservation (NYSOPRHP) requested that Erdman Anthony evaluate the condition of a timber trestle bridge within the Old Fort Niagara State Historic Site in Youngstown, NY. The bridge provides access to the draw-bridge at the Gate of Five Nations entrance to the fort, one of a limited number of entrances allowing visitor access beyond the fort's walls. Fort Niagara is a State Historic Site that dates back to 1679. The bridge, however, is not believed to date back this far. While the actual date of its construction at this location is unknown, it is estimated to be approximately 1756 as part of one of many additions at the fort. The Gate of Five Nations at the northeast end of the trestle bridge was constructed at that time, based on historical records, and the trestle bridge would have been necessary to cross the moat and gain access to the drawbridge for this entrance.

NYSOPRHP requested that Erdman Anthony perform an inspection and structural evaluation of the bridge. The scope of the inspection was to determine the condition of the bridge, evaluate its load carrying capacity, and determine which, if any, repairs would be necessary. An order-of-magnitude estimate for the recommended repairs was also included.

The structural components of the bridge were inspected visually and with pointed awls. The depth of penetration of the awl into the wood indicated the degree of deterioration or section loss of the members. The bridge was analyzed for a live load capacity based on current American Association of State Highway and Transportation Officials design criteria for pedestrian bridges. Based on the extent of the deterioration and the configuration of the bridge, it was recommended that the entire superstructure and the pier cap beams be replaced. Erdman Anthony completed design plans for the rehabilitation of the structure to make it safe for the high daily volume of pedestrian traffic accessing Fort Niagara.

Project Details

Location

Niagara Falls, NY

Owner

New York State Office of Parks Recreation & Historic Preservation

Project Contact

William McCormick, PE
  • William McCormick, PE
  • 585-427-8888 x 1080
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