Virginian's AE was one of two locomotive classes ever to use two sets of ten drivers, the other belonging to Atchison, Topeka & Santa Fe. The primary difference between the two was that AT&SF's were actually built out of two 2-10-2s, while Virginian's were designed to be 2-10-10-2s from the start. AT&SF were not thrilled with the performance of their engines, and soon rebuilt them into 2-10-2s, but The 10 Virginian AEs, built in 1918, were kept in service for over 30 years. One feature immediately obvious about the AE, aside from its many drivers, is the comically small tender (admittedly scaled up slightly in my model to hold the motor). The small size was due to restrictions on Virginian's turntables.
The AEs were true Mallet articulated engines, and typically operated in compound expansion mode, where high pressure steam was fed into the rear set of cylinders, and the exhaust fed into the front two. That explains the 48" diameter front cylinders, the largest on any steam locomotive as far as I am aware. They were capable of operating in simple expansion mode, and could generate an earth-shaking 176,000 lbs of tractive effort this way, making them one of the most powerful locomotives ever built. These impressive statistics meant that, even with a fairly large boiler, the AE could only sustain speeds of 8 mph. however, that was sufficient for pulling heavy coal trains assuring the AE a useful spot in Virginian's roster.
Due to the AE's relatively small drivers, only 56", I wanted to scale this build to Big Ben Medium wheels. Thus, this engine is somewhat smaller scaled than my other large steamers. It is powered by a single Power Functions XL motor in the tender, where all of the PF gear is housed. I utilized the new PF minitruck design that Anthony Sava and I worked on a few months back, so far with limited success, though the engine runs well enough as is, the light weight of the tender translates to a lack of adhesion I have yet to fully remedy.
I love it! This is a great looking locomotive. The history lesson that you give us with this is very interesting and informative. I love mixing history and Legos; they go well together. You have done an outstanding job of working with them both to build something excellent.