Originally built as a coal burning steam locomotive in 1927 for Santa Fe Railway in cooperation with Baldwin Locomotive Works, this massive steam engine was one of the most powerful in its class. The original price tag was $99,712.77. In 1936 it was converted to burn fuel oil at the San Bernardino shops. It carrries 7,101 gallons of fuel oil and 20,000 gallons of water. It is capable of reaching speeds of 90 m.p.h. on level track. With a boiler horsepower raiting of 5,000, it can pull 105 freight cars (5,949 tons) on a level grade at 45 m.p.h. Old 3751 pulled its last passenger train from San Diego to Los Angeles in 1953, and was officially retired from Santa Fe in 1957.