Removed from its river piers and slowly rotting away in North-Eastern New Hampshire is one of the most fantastic pin-connected spans in New England. Built in 1897 by the regionally prolific Groton Bridge Co., this span is the longest (just over 500 feet) left in the region that employs pinned connections for its members. Most of the deck has rotted/been removed, and some of the decorative elements have been lost, however this bridge still retains a exceptional amount of historical integrity and represents an ideal candidate for restoration and rehabilitation, given its beautiful and historic nature.
The first bridge at this location, it replaced a low water fording. The cost of the structure was $10,000, and required a combination of financing from the state ($2,500), town ($4,000) and the citizens themselves, as the state appropriation was reduced from an original $6,000, requiring the remaining $3,500 to be raised locally. The bridge opened to much fanfare in October of 1897, and remained in service until bypassed by a new bridge in 1984.
From west to east this bridge is comprised a pony Pratt truss (71 feet), 3 identical Pratt through trusses (131 feet each), and a small steel stringer approach (21 feet). Abutment to abutment comes in at a little over 504 feet. The substructure consisted of cut stone abutments and concrete filled Lally columns providing the river piers.
Perhaps because of the high level of local pride in the structure, expenses were not spared on this bridge, as it had a beautiful set of cast iron portal cresting and finials, as well as a fine builders plaque. While not uncommon, these features were certainly on the wane by 1897 and are thus noteworthy. Some of these features still remain (portal cresting and the western builders plaque), although the elegant finials are long gone.
As stated the bridge was bypassed in 1984, but continued to serve as a pedestrian crossing until its main river pier was compromised. When the bridge was fabricated in 1897 the Androscoggin River maintained a width of nearly 400 feet, however due to a natural shifting of the stream bed the river at the bridge site is now only about 250 feet in width, with the channel having shifting eastward. The higher flow rate experienced by the eastern pier caused excessive scouring, which in turn caused the pier to begin to collapse.
An emergency removal of the bridge was executed in 2004 before the span could completely collapse, with 1 span being removed to the east bank and one to the west bank. The wooden deck from these spans was removed, and they were placed on steel cribbing until a fate for them could be decided. The remaining spans (the pony, 1 through truss, and the stringer span all remain in their original locations).
There has been a strong local interest in preservation / rehabilitation of this bridge for some time, however the cost has been prohibitive for the tiny town of Shelburne, hence the lack of action. Other ideas as simply salvaging 1 span for rehabilitation have been suggested, but nothing has yet been decided.
The attached PDF report from the state SHPO indicates that this nationally significant historic metal truss bridge is at significant risk for demolition. Also note that according to another SHPO report, "Compared with the forty-three metal truss bridges still in use, New Hampshire has fifty-four covered bridges."
That metal truss bridges, both newer and more permanent in design, would number less than covered bridges suggests a serious shortcoming in NH historic bridge preservation policy.