A westbound BNSF freight passes by the former Santa Fe depot in Amarillo, Texas, on June 16, 2012, with a new GE ES44C4 leading the train. The unique A-1-A truck design can be seen (no traction motor on center axle) with the two extra cylinders connecting to the center axle a giveaway. GE calls the system “weight management control,” and in the this system, under heavy load and at low speed, air cylinders and a bell crank mechanism actually lift the center axle from the rail to shift more weight to the outer axles, giving the locomotive more tractive effort.
