Dominic Mazoch posted:
Advantage of the A-A-1 traction motor arrangement for the AC truck vs A-1-A for the E units?
Completely different truck designs. The old/original Blomberg A-1-A truck (yes, the same Mr. Blomberg that later designed the famous 2 axle truck with 40" diameter wheels for the FT units) had only 36" diameter wheels. The HTC-R "Radial" truck is far superior, and due to its "steerable" design reduces flange contact/wear on curves, not to mention far superior adhesion for high traction situations.