Since you are interested in operations and want to keep the continous running. You might consider changing your concept of the operations. You have a yard area and terminal on the main table. and you have some staging off in another room. Consider running "through" freights from staging to the main terminal. There they would terminate, Later a reverse move would be assembled at the yard and go back to staging.
The cars that come in from staging would be classified into locals and a local engine (generally smaller) would take them out along the branch to deliver, and to pick up outbound cars. these outbound cars would them be assembled into the through freight (or transfer run) back to staging.