Taken in 1979, here is a great old photo of the Alco 902 16,000 horsepower diesel electric locomotive.  At this point time, the Panama Railroad was starting to go under.  The 902 pictured above still had the U.S. Bicentennial logo and colors from 1976.  As stated in the January 4, 1952 issue of Panama Canal Review, "People would turn and look when they heard the melodious three-toned tootle.  You can see the three horned whistle to the rear of the exhaust stack.  There were three of these Alco diesel electric locomotives purchased by the Panama Railroad in 1952 (901, 902 and 903). Delivered to the Canal Zone by way of the Panama Line ships and unloaded by the Floating Crane Hercules, they added a much needed upgrade to the freight and passenger service on the Panama Railroad.

I recently obtained this great photo on a 35mm slide.