Here is the justification to mount flags on your locos.
“I got a sheet of flags from you and I have been using them around the railroad, but today I saw an authentic use for one on a locomotive. I was running errands around town, and I am fortunate that the CSX River line, formerly the Conrail River line, formerly the NYC West Shore Line. I caught a train going through today, and on the lead unit, there was an American flag fastened to the center post of the windshield, and sticking up about two feet above the roof line of the cab. At 50 MPH, it was flapping like crazy, and looked great!! There’s a prototype for you.”