I have a 46', 726. I have upgraded my 726 to a high stack motor. Runs well. It has been described well. I like not having an e-unit lever sticking out the boiler. Also the front and rear wheels do drive, but the middle ones do little for pulling. They have vertical play where the bearing fits in the casting. They float up and down a little. I call them gravity loaded not spring loaded.
47 and on the drive train changed allowing better precision in aligning all the wheels. Savings in manufacturing also.
The Berkshires and the Hudsons is they drive one set of wheels with the motor and the linkage is active to drive the other wheels. On other designs the steam engine wheels are linked with gears and the linkage is along for the ride.
It doesn't puff as well as later units. It does have a flapper to puff. Since the original smoke pellets caused corrosion, the smoke bulb housing may have corrosion problems if too many were used. The 1946 smoke pellets are toxic and a fire, corrosion and explosion hazard. (maybe if the whole bottle got hot) Same stuff that blew up Texas City in 1947. Which probably moved lionel to replace the smoke pellets with something else soon after. Amonium nitrate is also a fertilizer base.
