One of the Southern Pacific's famous "Cab Forwards," Class AC-12 4-8-8-2 #4294. This is the only surviving example of these unique locomotives; it now sits on display at the California State Railroad Museum in Sacramento. Postcard from the Richard Anderson Collection
In the 1960s, Krauss-Maffei built several examples of ML-4000 diesel-hydraulic locomotives for demonstration and testing on American railroads. Southern Pacific Railroad and Denver and Rio Grande Western Railroad participated in the tests, but both found the locomotives unsuitable for service in the rugged Rocky Mountains through which the two railroads ran.