Highly interesting detail that a supposedly-inflexible T1 is rated for tighter curves than a GG1 at each given speed. Doug, I think this 'table' deserves its own thread here, as very few people reading this thread are likely to open the image and read the note on the side and then go down to the bottom...

Well, the standard Fairmont wheel is 16”. It comes in either stamped (the ubiquitous speeder wheel, bolts to a cast hub) or cast (which are solid dished wheels). The other standard size is 20", also on stamped or cast, but usually cast. The flanges are smaller than RR, bigger than streetcar (they will flange-ride on streetcar track) but look outsize large on such a small wheel. The cast versions are common on MoW equipment.

All of them differ from pressed railroad wheels by having a tapered hub, which mates to a tapered wheel shaft via insulation cones. This is so makers have the option of insulating the car from the track circuits. I assume someone sells steel "insulation cones" which obviously shunt. Otherwise omitting the outer disc insulator will usually have that effect.

See "Classifieds". This contraption is apparently now for sale.

/s/ Larry
Lawrence G. Lovejoy, P.E.