 Further notching out of the controller shorts out the starting resistances in pairs until in starting notch #16 all of the starting resistances are shorted out; this corresponds to running notch #3 on the engineer's controller.Moving the controller to starting notch #17 weakens the traction motor field to 67%, and in starting notch #18 the field is weakened to 50%.Starting notch #18 corresponds to running notch #4 on the engineer's controller; this is the maximum notch and allows the train to reach top speed.