Re: Overhaul versus rebuilt

Somewhere I have the list of items "renewed" in the various classes of overhaul of steam locomotives. A "class 1" overhaul was a very heavy overhaul and included things such as a new boiler and frame. I remember a "Class 3" included new flues, driver tires, major renewal of running gear, firebox work, etc. A "class 5" was a tire turning, new rod bushings, etc.
I have never see pics of 481 stripped down in Alamosa to see what they did to her. Photo's of 497 show her stripped down, all running gear off, frame looked to be marked up for new shoes and wedges, etc. This would indicate a "Class 3" overhaul.
As anything deeper than a "class 3" involved major firebox and tubesheet renewal, I doubt any locomotives got any work of this magnitude after about 1955.
As to 481, unless someone can state differently, I would say she got a Class 3 like 497. If she needed anything more, I think they would have chosen a different engine to work on.