Can someone explain why some box cars have both a Plug door and a sliding door? Why have one of each???
Versitility.
A plug door is flush with the interior walls of the car. If you only need a 10 ft door then you can use the sliding doors and the plug door is just another part of the wall. If you need wider doors, 15-20 ft, then you can open the plug door too.
If you had two sliding doors, the car wouldn’t be best for many commodities, because the loading pattern relies on a smooth interior wall except for the door (the stacked commodity rests against or is braced against the car walls to minimize shifting). You can brace against a plug door (making 40 feet of a 50 ft car useable) but not against a sliding door (making 30 ft of a double sliding door boxcar useable).
Dave H.