The SD90's did some interesting damage to the track in that they could spread the gauge, drop in between the rails for a short distance, then magically rerail themselves. If you were there to witness the event the only evidence was scarring on outer surface of the wheel. There was not marks on the ties, or any other evidence. I was running an SD90 that did this trick one day. There was a jerk, a loud "bang" and everything kept moving ahead like normal. I stopped a mile or so later at the summit (Fir) and saw the fresh scars on the wheel rim. It was a true "Oh $%^*" moment. I wrote a note to the roadmaster explaining the situation. He went out to the spot, saw nothing. Two nights later in a white-out blizzard, I hit the same spot. There was definite low joint in the curve now, but we crawled through at 10 mph. 25 cars later, we went into emergency. tTe conductor went for a walk in the snow and reported the last car on the ground. Asked him for the car number..... It was 3rd car from the end. The other 3 were on their sides down over the bank.

The B-39's ran well. I liked them. They pulled well. made nice chugging sounds that made for a nice lullaby to nap by. They had regular 26 brake, unlike the desk tops the SD90's had.

We did a lot of running long-hood forward. Especially on the concert trains from La Veta to Fir. Running an SD90 long hood is impossible. You cannot sit at the desk and turn around to see backwards. I saw the world through the review mirror, while my conductor sat on the left side.

The steam locomotives (SP 1744, LS&I - Grand Canyon - 18) had no issues with the curvature or the 3% grades.