Long freight train stops at freight yard. It begins to UNLOAD. The engine moves the train forward appropriate to the unloading action. The entire freight can not fit on the freight siding do it must pull onto another track as it unloads. Problem is that the junction/switch never switches to the freight yard siding. No other train is active at this time. The train simply sets waiting for the switch to allow it to move to the other track and continue unloading. 
