Alco: RS-3

The Alco RS-3 road switcher locomotive was the first type of diesel road switcher locomotive acquired by the Reading.  Assigned the Reading class RS-1 and numbering a total of 67 units, they were the most numerous class of locomotive on the railroad, and could be found performing a variety of duties all over the system.  Many consider the RS-3s to be the "definitive" first-generation Reading diesel.  The first group of Reading RS-3s were numbered 500-509 and were delivered in April, 1951, and entered freight service on the New York Branch between Bridgeport and points in New Jersey.  In July of August of that year, locomotives #510-524 arrived and were used in the same territory.

The initial success of this first group led the Reading to order additional in 1952.  RS-3s #496-499 entered service during May, 1952, and were used on crossline freight between Rutherford and Allentown/Bethlehem, occasionally venturing west to Hagerstown, MD.  At the same time, units #460-475 were delivered.  These locomotives were intended for passenger service out of Philadelphia, and were equipped with steam generators.  During the summer of 1952, locomotives #484-495 arrived at Rutherford, replacing N-1 Mallet and I-9 Consolidation steam locomotives operating there, accelerating the demise of steam on the Reading.  The final ten units, #444-450 and #481-483, arrived in October and August 1953, respectively.  These units replaced remaining I-9 and I-10 Consolidation steam locomotives.

The Reading's Alco RS-3s initially operated all over the Reading and Philadelphia Divisions, but did not venture north to the coal regions.  The versatility of the "road switcher" type of locomotive, as opposed to a cab unit such as an EMD F-unit, was proven by the great variety of assignments for these locomotives in their early years:

Abrams:  Yard drill, Philadelphia area branch jobs (Chester Valley, Plymouth), and mainline service to Bound Brook/Port Reading.
Bethlehem Branch:  Local, mainline, and iron ore extra service.
Reading:  Reading & Columbia / Wilmington & Northern through trains, Joanna Turn ore train, yard service.
Rutherford:  Lebanon Valley & Gettysburg branch locals, crossline and mainline freight service.
Philadelphia:  Run-through service on B&O trains to Jersey City.

Passenger service was most frequently the Main Line and North Penn trains to Reading, Pottsville and Bethlehem.