I see the north end of this route also quickly enters a tunnel.
This bridge replaced an 1872 structure and reused the original piers. It is part of a route that allows through trains to bypass Pittsburgh. Port Perry was such an important railroad town of 3000 people that it no longer exists. Its land has been completely covered by the tracks of NS, CSX (B&O), and the Union Railroad. [pghbridges]
The following two diagrams are from page 22 of the USACE Jan 2004 Monongahela RiverNavigation Charts.
The pool change associated with the Lower Mon Project will raise navigable waters in existing Pool 2 five (5) feet, thus reducing the vertical clearance of the bridge to 40.6 feet, making it 1.9 feet lower than the U.S. Coast Guard required vertical guide clearance of 42.5 feet....One option preferred by the Corps would replace span 7 (407-foot span between piers 7 and 8) over the navigation channel with a new span constructed of higher strength steel and a modified truss design to achieve the required vertical clearance without changing the rail grades. This option can be achieved through various plans to either rehabilitate or replace Piers 7 and 8 to handle the additional loads of the new span. [pghbridges, search for "1999"]
|Robert S. Dorsett posted|
Another Hot Metal bridge is Pennsylvania's Port Perry bridge. Built in 1903, carries Norfolk/ Southern R.R.