August 23, 2008 Congratulations, Ashtabula, Ohio, now home to the Nations Longest covered bridge. The new bridge is a milestone in highway bridge technology in that is constructed of wood instead of steel or concrete. Given the longevity of 100-years plus of timber bridges in Vermont, Ohio, Indiana, and elsewhere, it was long past time for the engineering community to have taken advantage of the properties of wood. Let them study this new bridge, learn from it, and go do likewise.
However, I just read an article about the new bridge published by the Cleveland Plain Dealer on http://blog.cleveland.com/metro/2008/08/ashtabula_county_covered_bridg.html that has to be answered.
In spite of being given the facts in a telephone interview about the Cornish-Windsor bridge, the intrepid reporter wrote: "The Cornish-Windsor Bridge over the Connecticut River can no longer claim the title as America's longest covered bridge. The historic structure, built in 1866, runs a measly 449½ feet while connecting Cornish, N.H., to Windsor, Vt., according to the state."
Actually, Mr. reporter, it's a "measly" 460 feet long, long enough to cross the Connecticut River at this place. It was built in 1866 by James F. Tasker and Bela J. Fletcher, two good New Hampshire bridge-wrights using 19th-century technology and the rules and skills of expert carpenters (no computers and engineering software), and without engineering degrees.
The Cornish-Windsor bridge was built by hand (no power tools), and erected without a regiment of cranes to lift timber and stone into their places. It was built on a single pier for a reason: the Connecticut River doesn't tolerate piers—it builds dams against them out of ice, trees, and houses and destroys the bridge. Three bridges built on this site were all destroyed by the Connecticut River. Not this one—our guys designed the bridge using a timber version of Ithiel Town's lattice truss capable of the longest single span attempted in this place.
The one pier supports two bridges, each 230 feet long (divide 460 by 2). The Ashtabula bridge, 613 feet long, is supported on 3 piers, that is four bridges, averaging roughly 204 feet in length. The Windsor-Cornish remains the longest two-span covered bridge in the United States, which, according to New Hamphire's historic site marker, is all that it claims to be. Next time, please Mr. reporter, get it right.