If I recall correctly, the general consensus was that the Big John was simply a 2-truck diesel-type model using existing steam engine parts investments by Hartland and that there weren’t any real prototypes behind the model.
However, while exploring a geared steam site, http://www.gearedsteam.com/ , I stumbled across a couple of manufactures I’d never even heard of, including Baldwin’s FIVE geared engines, four climax-like and a single shay-like, both using standard BLW construction practices and parts.
They have a bunch of different parts to the site including one for the Bell Locomotive Works, Inc. of New York City, New York. If you scroll down to the seventh engine type, you will see something that looks very much like Big John, but using Stanely-Steamer-like steam motors on each truck. Direct Link: http://www.gearedsteam.com/bell/double_truck.htm (turns out the main offices were in NYC, but the works was in Bloomsburg, PA… just a tad east of Danville.)
While the Big John model proposes to use horizontally-flat cylinders in a heisler-like drive train, I wonder if someone who designed Big John had seen a picture of this Bell engine and not knowing about the steam motors, just invented the power cylinder locations. Just an idle hypothesis. Any thoughts?
If nothing else, if you have any interest in geared of pygmy steam power, you really should check out http://www.gearedsteam.com
