That's the thing. This big iron equipment doesn't just quit working and fall apart after a few years. It's expensive enough that you rebuild engines, weld up pa

That's the thing. This big iron equipment doesn't just quit working and fall apart after a few years. It's expensive enough that you rebuild engines, weld up parts that break, redo seals in the transmission, etc, and keep it going for decades. I've driven Cat D6 bulldozers that were older than I was when I was in college, and they are still going, a decade later. Particularly the stuff that is built for heavy usage has to be used hard, patched together with limited repair facilities in remote places, and handled by inexpert operators.