If you look closely at the locomotive, one end of the shell (down low just above the frame, about 1 1/2" in from the nose) will have a small "F" on it, indicating it's the front. GG-1's would run in both directions with just the crew swapping sides. The "F" was to help the maintenance crews with reporting of problems.
The engine would have been operated with a fireman on the opposite side to help with visibility issues, you can't see the other side. Fireman would help out in clearing signals or calling out anything happening on the other side.
