During the late afternoon we see southbound CSX Q133-21 (North Baltimore,OH-Jacksonville,FL) stop on the single main along Nickajack Lake on the CSX Chattanooga Sub in Haletown, TN (MP J-130.1). What you don't see in the photo just a quarter south of this train standing in position is the Subdivision Road Foreman of Engine, and Train master as the conduct the monthly banner testing. A “banner test” is conducted to test a train crew’s compliance with Restricted Speed. To conduct this test, a trainmaster will place an obstruction (sometimes called a “banner”) on the track ahead of a train that is required to proceed at restricted speed on a main track. The obstruction is large enough (with reflective tape for night tests) for a train crew to see in plenty of time to stop their train. Usually, a train master is the one who conducts the test, but he or she may be joined by a road foreman of engines (who supervises engineers), or perhaps a more senior operations manager like a terminal superintendent or someone from division headquarters. This is usually a two-person operation. The test must also be carefully coordinated with the train dispatcher. Which is one of the reason why they conduct these testing away from the terminal to prevent a lot of disruption of rail traffic. Photo from the John Kirk Collection
