When I was the manager for the standard gauge contract switching company there 10 years ago they were loading 100+ centerbeams of Sheetrock (USG trademark name though everyone called it "board") plus quite a few covered hoppers of dry mix for their board plant in Santa Fe Springs. THe recession and housing crash hurt the plant hard. Last I heard from the owner of the switching company they are down to shipping hardly anything by rail. I had heard one of the two production lines was still shut down. Few sales means little need for the NG to bring more gypsum into the plant.