I am not sure from the aerial photo if the cars are on the mainline or not. I am wondering if the point where I have placed the dot is the main. The two cars are just below and to the left. The tank is the prominent object below on the other side of the road.
I don't recall them being loaded with much other than a few pieces of trash thrown in by those that don't care. If they have been painted it was after may of 2000.
The link below will get you a view of the cars from the tank.