The AC6000CW (C60AC) is the most powerful diesel locomotive ever built by GE. 311 were built for three railroads. It can be distinguished from the AC4400CW by the large radiator overhang at the rear. Most but not all have steerable trucks. http://www.northeast.railfan.net/images/tr_csx602b.jpg The overhang http://www.northeast.railfan.net/images/ge6000.jpg GE demonstrator; note hi-ad trucks http://www.northeast.railfan.net/images/gecx6001.jpg GE demonstrator; note hi-ad trucks http://www.northeast.railfan.net/images/up7544.jpg UP http://www.trainweb.org/csxphotos/photos/CW60AC/0600CSX-bc.jpg CSX bright future; note hi-ad trucks http://www.trainweb.org/csxphotos/photos/CW60AC/0601CSX-bc.jpg CSX bright future; note Dofasco trucks http://www.northeast.railfan.net/images/csxt0682.jpg CSX bright future with yellow letters http://www.railways.pilbara.net.au/bhp/loco/ac6000/pages/ac_16.html BHP Iron Ore (Australia) http://www.railways.pilbara.net.au/bhp/loco/ac6000/pages/ac_24.html BHP Billiton (Australia) There is no ES-series counterpart.