Surprise, surprise

I've seen this little switcher at the Knoxville Locomotive Works for years; but never looked it over. I assumed it had a little 4 cylinder gas or Deisel motor, with some transfer gizmo to get the power to the wheels. But I was wrong. In the first picture below, you can see a red generator on the back of a yellow motor. in the second picture, you can see the one electric traction motor on the axle, with a chain to carry power to the forward axle. So Thumper is actually Deisel-electric, Thumper is in the Big League! Way to go Thumper, you da locomotive!
Prime Mover and generator
Traction motor
Also, here's a picture of the other side.
More sun hits this side