Thats one of the reasons I don't like any of the 'Push' trains with the powered Tenders. Is she derailing in one particular spot on the Layout or like every general curve or point?
I would agree with with Marc above in trying weights in the front of Emily. Also make sure her wheels are clean, especially on the sides and that those front axles move freely.
I would agree with with Marc above in trying weights in the front of Emily. Also make sure her wheels are clean, especially on the sides and that those front axles move freely.