rail bridge question

[Bob C]

Hi, Jim ! Yopur bridge is still evident on Google Maps:http://maps.google.com/maps?f=q&source=s...9&t=h&z=16, and the left-most pier looks to be on the (straight) old alignment of the tracks, as witnessed by the mirror "S" curves on each side of the river. However, from the sat view - barges are moored to the ones near the south bank, (awaiting a turn through the locks?), and these piers are round, so more likely purpose-built for the navigation traffic (LOTS of those 'round Pittsburgh's 3 Rivers). The girder bridge may have been a repair, or a provisional fire-break in a loooong wooden trestle. The spacing of the legs would seem to allow the metal structure to be nearly erected without disturbing the wooden supports, perhaps allowing the transfer of "responsibility" to be completed with very little interruption of traffic, (PRR built the 2 track through truss Ohio Connecting bridge over the Ohio River AROUND the old single track span, and the deck truss and deck girder portions were constructed on cribbing and slid sideways into place to complete the change-over in about 8 hours, IIRC.) Bob C.