The Town Bridge
In 1820, the architect Ithiel Town wrote to Eli Whitney requesting a written opinion of the model of a wooden bridge on which Town that year had filed a patent. Whitney's reply, "its simplicity, lightness, strength, cheapness & durability, are in my opinion such as to render it highly worthy of attention," recognized the admirable qualities of Town's bridge, which was in fact a major design innovation.
The lattice truss was an uninterrupted series of closely spaced diagonal timbers. The resulting web of overlapping triangles affected the distribution of stress to all members, so that the independent action of any one triangle was impossible. Ordinary pine or spruce planks were used for the diagonals and wooden connecting pins or tree-nails fastened the members at their points of intersection. This "garden trellis fence" concealed a truss design of considerable strength.
Not only was Town's design strong and made of economical standard-dimension lumber, it was also easy to build: it did not require fancy mortises and tendons and could thus be erected by a common carpenter's gang; it did not have to be custom-fitted to piers or abutments as arch bridges did. And the lightness of its timbers reduced the amount of labor that had formerly been needed to erect the pioneer bridges of Town's predecessors, Timothy Palmer and Theodore Burr. Thus the lattice-truss bridge combined the features of strength and economy, which had great appeal, especially to those engaged in the expansion of the nation's transportation network of highways and later, railroads.
The original bridge, located a distance north of the Whitney Site, was destroyed in flooding around the turn of the 20th century. In 1979, students from Eli Whitney Vocational-Technical High School reconstructed the bridge at its current site. Though it is built atop bridge abutments from an earlier factory bridge, Town's design would have been strong enough to span the river without such additional supports.
