This is a look at the many engines of the UP, including switchers, 4-6-2s, 2-8-2s, 4-8-4s, 4-8-2s, 2-10-2s, 4-10-2s, 4-12-2s, 2-8-8-0s, 4-6-6-4s, 4-8-8-4s, Diesels and Turbines. many Photos.