The Warren Truss Covered Bridge

In 1848, James Warren and Theobald Monzani patented the Warren truss in England. A year or two later, American civil engineer Squire Whipple (1804-1888) gave this type of truss its first practical application in the United States. The Warren truss has parallel upper and lower chords with inclined web members sloping in opposite directions to form a series of triangles. The uniform size of the members made fabrication and erection economical, and the simple configuration allowed the diagonals to alternately carry tensile or compressive stresses under moving loads. Warren truss bridges of wood appear to have been limited to Ohio, where three covered bridges of this type survive.