Locomotives like the SDP-35 or SDP-40 were basically a freight unit with a steam generator on the back porch, right? The frame is the same as a freight version SD-40, but a little longer for the steam generator, which isn't as heavy as the motor anyway and is still supported by the back truck, right? Where as the EMD 'E' series loco's carried the weight on the longer A-1-A trucks, verse say pushed together in the middle of the body. Should they have beefed up the frames to put whatever in the center of the car body type? I would have thought that was a no brainer.... 'Side's, the 645 sound ISN'T the lovely sound of two 567's. More maintenance I know, but MORE jobs!