The cement arch bridge, crossing the Salamonia River in Portland, is the only concrete bowstring truss bridge in Indiana.
Built in 1914 by the Isaac E. Smith contracting firm of Wayne County, the bridge was designed by O. O. Clayton, a Portland civil engineer. The bridge cost $10,240 at the time, and so much concrete was used that it was allowed to cure for six weeks before the bridge was opened to traffic.
The columns which passers-by might assume support the bridge’s pair of concrete archers actually work as “hangers” which allow the arch to support the bridge deck.
When the bridge was initially constructed, the first step was to build a “falsework”, a frame support system which filled the river’s channel. That timber and lumber framework provided the support so that the bridge’s deck could be poured, ten inches of concrete interlaced with steel reinforcing rods.
The steel-reinforced concrete vertical sections were then cast and when the arc of the bridge was cast it assumed the ob of supporting the bridge deck and beams. The falsework could then be cleared away.
In late 1997 a half-million dollar bridge restoration project was completed.
The bowstring truss bridge is included in the central business district listing on the National Register of Historic Places.