Operationally, mainline mixed freight trains stop to work the yard as they pass through the layout. For right now, the PML has four mainline mixed freights. Usually two to three of these run in a session. The road crew ties their train down on the arrival and departure tracks, splitting their usually-lengthy train to fit, then runs their road power to the engine terminal for servicing. The yard crew then works the mainline train, removing cars bound for online industries and interchanges and adding cars bound for staging in the same direction as the train's destination. Once the yard crew is done putting the train back together, the road crew doubles up their train and heads for points east or west.
The yard crew is also responsible for putting together locals on an as-needed basis as cars for local industries accumulate in the yard. All locals operate as turns. They pick up power from the engine terminal, pick up their train, work the industries off one main on their way out, work the industries off the opposite main on their way back, and tie down in the yard.
Pitcairn has turned out to be a major hub of operational activity on our layout. See the photos below for a tour of the yard, working east from the western approach to the yard.