• Frame sag?

  • Discussion of General Electric locomotive technology. Current official information can be found here: www.getransportation.com.
Discussion of General Electric locomotive technology. Current official information can be found here: www.getransportation.com.

Moderators: AMTK84, MEC407

  by MEC407
 
Sometimes the outer edges of the frame (i.e. the walkways) appear to sag or be bent, but generally the inner part of the frame is fine. Sometimes the camera angle, or lens distortion, makes it look worse than it really is.

FWIW, I've seen this on many locos and cars, some of them much more severe than the ones you linked to. Photos can really exaggerate the visual effect, especially if taken from far away with a zoom lens.

  by GOLDEN-ARM
 
I led a straightedge against the first photo, and found the black strip to be straight. It looks bent, but isn't. Same for the second one. Catwalks aren't part of the frame, and they can wave up and down, without regard to the status of the underframe. Keep asking, keep asking..........

  by trainiac
 
There's often a slight bow in the walkways on locomotives between the jacking pads, and that may be the case here. The very slight tilt in the middle handrail stanchions supports this. However, those side frames are very weak compared to the inner supporting frame--which will often remain straight even after a head-on collision.

I've also noticed that some locomotives (such as the MLW M420W) have regularly spaced braces under the walkways that keep them perfectly straight.

  by uhaul
 
Thanks for all the answers.