Dear Tom.
We visited the Central back in the Sixties just before the PC Merger. Lovely Railroad, but, worn out. The end was near, and it showed.
Rolling Diesel Spotters Guide!!!, which had not come out yet. Saw almost everything Built except for Lima powered Limas and Central PAs. Saw EMD Repowered C Lines years before, but, did not know that until we check Numbers with a Roster. Sharks came later on the MRy.
Literally dozens of Alco Switchers in every Paint Scheme everywhere one looked on NYC, PRR, NH and most Industrials.
We could read Builder’s Plates, but, don’t recall seeing any NYC Switchers before 1944 or so. Different Story on NH and CV.
Since then have learned a lot more by fine Rosters in Magazines, and, with the Internet.
Alco used the SMALL Cast iron Alco Plate on it’s EARLY S Series Switchers into 1941??? So if one sees a Photo of a 539 with the Small Plate its OLD!!!
This Small Alco was used on Alco Industrial Steam and some of the First Alco DL 109 Twin Engine Passenger Diesels.
There has to be an Expert that knows when Alco changed from the Small Alco Plate to the Large Alco-GE Plate in Brass as Applied to the RS1.
I understand the First Alco S Series had a Almost Flush Circular Fan visible from the ground. Later Ss getting a Square Box above Fan. Another Spotting Feature of an OLD Alco. Did they get Covered as a Retro Fit? to keep feet out??
Check Kirkland Alco Book for Vintage Photos of First S1 and First S2.
( There is a Dec. 1941 S1 Pictured in the Kirkland Book bound for a Munitions Plant in Canada in the Month of Pearl Harbour. This Locomotive was sold after the War, and is still IN SERVICE in Southern Ontario in sight of Detroit. )
http://www.trainweb.org/oldtimetrains/industrial/ont/hearn200.jpg
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