I noticed something in an ETT a while back referring to Southern 6 axle Units running across the Mississippi River Bridge at Memphis. I researched this off and on and never came up with anything, so I've decided to start a thread to see if any knowledge or photos exist that I can't find online. What we do know from discussion in the Run-Through thread is that the Southern interchanged a lot of cars with the Frisco at Memphis. Both roads carried large blocks specifically for one another, but nothing in the schedules or operating data sheets indicated that they had a full on run through service with pooled locomotives. So to the point of this thread, look at this section of the Northern Division ETT from April 1979. This set of instructions makes it sound like Southern locomotives did occasionally go over Frisco trackage. I'm looking for a reason why (if one exists), and or images of the two operating together (if one exists).
