I grew up in Wheeling WV with the B&O running past Tunnel Green a few hundred yards behind the house.  It crossed a stone Viaduct into tunnel No.1 and across a Pennsy line that ran through 2 long tunnels and exited onto a long steel bridge that crossed the Ohio river.  I used to walk through them and it was quite an adventure, trains were still occasionally running at the time.  I was in ND during the late 60's and got a short ride in the cab of a SOO F unit.  Awesome!  I remember the conductor or brakeman shouting a few choice words over the radio as the train backed a little hard to couple cars.