Southern Pacific No. 3900

Southern Pacific No. 3900 was a Class "AM-2" 4-6-6-2 Cab forward type steam locomotive that was owned and operated by the Southern Pacific Railroad (SP). It was built by the Baldwin Locomotive Works in July 1911, as SP No. 4200 as a mallet compound part of the Class MM-2 locomotives which originally had a wheel arrangement of 2-6-6-2 and were used for passenger service. It was modified with a four-wheel pilot truck by 1914.
In December 1928, it along with rest of its class were taken to the SPs Sacramento shops. They received a general rebuilding that included a superheater and a feedwater heater and were re-classed as the AM-2's. It was renumbered to SP No. 3900 at Brooklyn, Oregon in March 1938, to clear the number series for the new series of locomotives for the SP, known as the Class AC-8, which were on order for delivery in 1939.
It worked for the SP until it was retired in May 1947 and was scrapped in June of that same year.
Category:Built in 1911
Category:Locomotives
Category:Steam locomotives
Category:American locomotives
Category:American steam locomotives
Category:Tender locomotives
Category:Cab forward locomotives
Category:Cab forward steam locomotives
Category:Scrapped locomotives
Category:Scrapped steam locomotives
Category:Mallet locomotives
Category:4-6-6-2 Locomotives
Category:Baldwin locomotives
Category:Standard gauge locomotives
Category:Standard gauge locomotives of the United States
Category:Southern Pacific locomotives
Category:Passenger locomotives