The Ohio Connecting Railroad Bridge was built in 1915, and it still carries freight. It crosses the Ohio at Brunot Island, so that there are two main spans, one for the front channel and one for the only slightly narrower back channel. This is the front-channel span.
Nearest to farthest: Liberty Bridge, Panhandle Bridge, Smithfield Street Bridge, Fort Pitt Bridge, West End Bridge.
The Ninth Street or Rachel Carson Bridge: above, from the Downtown end; below, from the end of the Seventh Street or Andy Warhol Bridge.
Stanley Roush, king of public works in the 1920s and 1930s, did the architectural parts of this elegant bridge, which opened in 1933. It is almost shocking that, in a city with more bridges than any other city on earth, this is the only cable suspension bridge. (The Three Sisters are held up by steel rods rather than cables.)
We don’t pay enough attention to the railings on our bridges and viaducts. They were opportunities for architects to try out new ideas in decorative geometry, and a talented architect like Stanley Roush could produce designs worth pausing to admire.
The Bureau of Standards wanted to know what caused structural failures in bridges and how to prevent them. So…
A high-carbon steel column under test. Restrained lattice. Buckling of diagonals has begun
This picture comes from the front page of the Engineering News for July 13, 1916. The article explains some of the discoveries made possible by this huge apparatus, and would probably be very interesting to students of engineering.
The Birmingham Bridge is a generous bridge for the traffic it carries, isn’t it? And why are there these strange wings sticking out at the southern end?
The answer is that the Birmingham Bridge was built in the 1970s as part of a vast network of expressways that would bring Pittsburgh into the automobile age at last, by destroying much of the city and making it easier for suburban drivers to get to major destinations. There was to be an interchange at the southern end of the bridge, with exit and entrance ramps connecting to the bleak expressway-blighted streets below.
Almost all that ever came of the plan was the Birmingham Bridge; the fates had mercy on the city and scuttled the rest of the network. But the stubs of those interchange ramps are still there to remind us how close we came to making Pittsburgh the Los Angeles of the East.
The South Tenth Street Bridge, seen from the Bluff.
The current portals are not original; they were built when the upstream span was widened in 1915. The original bridge was designed by Gustav Lindenthal; the current portals were designed by Stanley L. Roush, who was responsible for many prominent transportation-related projects, including the entrances to the Liberty Tubes and Armstrong Tunnel and the terminal at the Allegheny County Airport.
The bridge is the oldest through-truss bridge in the United States, and one of very few with a Pauli or lenticular truss. The piers are even older; they were reused from the previous bridge, designed by John Roebling after the Great Fire of 1845 destroyed the old wooden covered bridge that had been put up in 1818.
