From the NRE website describing the requirements for the Australian units that the White Pass units are based on - The locomotives must be narrow-gauge (1,067 millimeter). They must have six axles, each able to carry 15.75 metric tons, with new NRE bogies. They must have 2,250 traction horsepower with a minimum radius curve of 80 millimeters. They must weigh no more than 94.5 metric tons with dimensions that do not exceed 3,900 millimeters in height, 2,850 millimeters in width and 19,018 in length.
2,250 tractive horsepower is a lot less than the 2,900 tractive horsepower figure Brandon is quoting. The curvature requirement is obviously a typo.
Michael Allen