| CSX 772 (ES44AH) is about to be fired up. The "H" in CSXT's class ES44AH locomotives stands for "high", which is in reference to a combination of subsystems that produce "high" levels of tractive effort at low speeds. In order to be classified as an "AH", a locomotive has to have not only an increased (currently to 432,000 pounds) nominal weight, but also (1) steerable trucks, (2) TM3 adhesion control software, (3) software that extends to 36,000 pounds (from 30,000 pounds) the maximum amount of tractive effort that each traction motor is permitted to produce, and (4) GE's Rail Cleaner, which directs high-pressure air onto the rails in front of the sand nozzles forward of number one axle. GE refers to locomotives with those features (though not necessarily the steerable trucks) as "HTE", which stands for "high-tractive-effort", locomotives. |