WESTERN VISITORS

The AP&W has been testing a trio of BNSF ES44C4's. Recently, they made a stop in Hillsdale...

As the employees look on, an engineer explains the difference between the ES44C4's and a regular ES44AC.

6641 is the oldest of the three, and thus has the most grime.

6916 is the newest.

And 6724 is the last unit in the consist. Among the differences between a 'C4 and a regular ES44AC are the dynamic brakes; not only does the 'C4 have two widely spaced openings, but the brake section is built-out on this side of the hood.

These two photos show the left and right sides of the other major difference between a 'C4 and a regular ES44AC; the trucks. The ES44C4 has A-1-A trucks, meaning the center axle is unpowered. A conventional ES44 has all three axles powered, and thus has C-C trucks. Additionally, the extra brake cylinders and rigging, as well as the control box above the truck (engineer's side only, but both trucks) are there for a unique purpose; to partially lift the center axle, allowing more weight on the outside axles for additional traction when starting a heavy train. The idea is to combine the lugging power of AC traction motors with the speed capabilities of a four-axle engine. During the early days of dieselization, many passenger engines were equipped with A-1-A trucks, as the center idler axle helped spread the weight of the engine and allowed good performance and handling at speed; the ES44C4 uses the same basic concept.