Pittsburgh & Steubenville Extension Railroad Tunnel Tags: Railway Tunnel.The Pittsburgh & Steubenville Extension Railroad Tunnel also known as the Panhandle Tunnel was originally built for the Pittsburgh and Steubenville Extension Railroad in Pittsburgh. It officially opened for rail traffic in 1865. point length (km) 438.912 height (cm) 5.6388 location Pittsburgh number of tracks 1, 2 opening year 1865-01-01T00:00:00+02:00 owner Port Authority of Allegheny County latitude 40.4411 longitude -79.9966 Learn more... Loading...