ALCO Century 636
 The ALCO Century 636 was the most powerful single-engine diesel-electric locomotive constructed by ALCO. The locomotive had a C-C wheel arrangement and 3600 horsepower (2700 kW). The locomotive rested on a pair of trucks of all-new design known as the Hi-Ad standing for 'high adhesion'. Visually it is similar to the Century 630 but can be distinguished by the intercooler box. The C630 has two grilles here one above the other. The C636 only has the upper grille.