Sulphite Covered Railroad Bridge, Franklin New Hampshire
The Sulphite Railroad Bridge, sometimes referred to as the "upside-down covered bridge," is a rare example of a deck-type covered bridge having its truss structure below the floor, or deck. This Pratt truss bridge was used to transport sulphur ore to a nearby pulp and paper factory. The Boston and Maine Railroad built it and operated it until 1973.
In 1828, Kendall O. and James L. Peabody and Jeremiah F. Daniell established a paper mill near the confluence of the Pemigewasset and the Winnipesaukee (Winnipisogee) rivers, at a site now known as Franklin Falls. In 1854, Daniell bought out the partenership and together with his son, Warren F. Daniell, formed J.F. Daniell & Son. In 1864, Warren bought his father's interest and became sole proprietor, operating the mill until 1870, when the mill property was sold to the Winnipiseogee Paper Company. In 1874, this company was annually producing "2,496 tons of paper, valued at $625,000." In the 1890s, the International Paper Company purchased the property.
Chartered in 1889 and financed jointly by the Boston & Maine and Concord & Montreal railroads, the Franklin & Tilton Railroad finished construction of its 5 miles of line in June 1892. The new road connected the Concord & Montreal's main line at Tilton with the Boston & Maine line in Franklin. The railroad opened with such poor prospects of earning profits that the State Railroad Commissioners stated in their annual report: "[The Franklin & Tilton] road is not operated except in a fitful way and is of little use to anyone. Its length is 5 miles and its cost was more than $200,000. We know of no other case in which so much money has been spent for so little purpose on a railroad project." However, the local paper industry made good use of the line, transporting large quantities of sulphur to the mills until the 1920s. In 1895, the Franklin & Tilton line was leased for ninety-nine years to the Concord & Montreal Railroad and subsequently leased to the Boston & Maine Railroad.
The first bridge at this location was a timber trestle bridge built in 1891. That bridge was replaced with the present Pratt deck truss bridge in 1896. No information has been found concerning its construction in the local newspapers. The 1897 Annual Report of the Railroad Commissioners of the State of New Hampshire lists twenty five "new bridges over ten feet span built within the year," including a 230' Pratt truss at Franklin.
The paper mills that gave extensive business to the Tilton & Franklin railroad line closed during the 1920s and service over the line was abandoned in 1973. Meanwhile, in 1965, the Sulphite Bridge was discovered "just by chance" by Richard Roy of the National Society for the Preservation of Covered Bridges and subsequently listed in the World Guide to Covered Bridges.
On October 27, 1980, vandals burned the Sulphite Railroad Bridge. Amazingly, only the siding burned off, leaving the charred trusses and metal roof in place. Four men were later arrested for starting the fire. The bridge was rehabilitated as part of a local rails-to-trails project, known as the Winnipesaukee River Trail, in 2006.