Just guessing. GEX-4 and RW-2 or RW-4 might have been combined at Mohawk or Schenectady and separated somewhere south of Richmondville because of routing restrictions to the south. Some heavy or dimension cars required special routing for clearance or weight restrictions. Some of those restrictions would appear odd unless you understood the reason. For instance, even though track centers (distance between adjacent tracks) were standardized, very long cars had center or end overhangs on curves so that they could not meet or pass another train alongside in that curve. Some curves at that time had as much as 6 or 7 inches superelevation and cars with a high center of gravity could only be operated at a minimum speed to avoid overturning to the low side, or at slower speed to avoid overturning to the high side. Those restrictions probably did not apply north of Richmondville.
