Diesel frames are cast or?

I’m clueless on this one. Are they cast or are they plates welded together? If a frame is bent, can it be repaired or the part of another one welded onto it?

Anything built in the past 60 years has a welded frame. They definitely can be repaired by welding. The limitation isn’t generally the technology, its the economics. If you’re just running the last bit of life from a 3rd hand GP9, it’s generally not worth fixing a bent frame.

A wreck damaged GEVO would probably be worth patching up.

This certainly fits in with the aforementioned 60-year timeframe: IIRC, when EMD came out with their first switcher units, they were offered in both cast and welded frames: the SC1 and the SW1, with “C” signifying cast and “W” signifying welded.

The ‘S’ in SC1 and SW1 stood for Six hundred horsepower, where the ‘N’ in NW1 stood for Nine hundred horsepower.

Baldwin used cast frames on some of its diesels well into the postwar era.