Switchers on the OB

Is there any yards or anything that would require two switchers on the OB?

I know yesterday they had an engine get towed back from OB but around 10 this morning two switchers went up the OB line.

Not quite sure about why they were there, but we do have 2 freight sidings, Roslyn team track and Seacliff team. Maybe some freight cars had to be switched out.