The Alco RS2, with its type 244 prime mover, developed 1500 horsepower, and the RS3 produced 1600 horsepower. They were used in passenger service on the New York Central's eastern lines, as in this August 1955 view of RS2 No. 8222 and RS3 No. 8318 at the depot in Pittsfield, Massachusetts. I have not been able to identify the train or its direction from the timetable covering this period; judging from the shadows, the time is late morning or early afternoon. The idling lead unit is putting out the usual Alco smoke, and the second appears to be emitting quite a bit of steam from its generator, which in August would most likely have been used for train air conditioning.

Alco RS1, RS2 and RS3 models had different pin configurations on their multiple unit connections. Some sources say this prevented their being mixed in multiple unit configuration — controlled by the engineer in the lead unit — although other sources assert they could me run in MU without modification. The practice apparently differed from railroad to railroad; reportedly the NYC's RS3s were all equipped for multiple unit operation at the "B" or cab end so the second unit of an MUed pair would be running "backwards" (the NYC considered the long hood as the front). It is known that the lead unit, RS2 No. 8222, had no MU connection on the front. If it likewise had none in the rear, then these units are not running in multiple. Instead, the second unit is running in "boxcar" mode, in which the engineer of the lead unit controlled the brakes but the trailing unit required its own engineer — as was the case in double-heading steam locomotives. Regardless of the jumper connections, differing brake types between diesel models (or even within the same model) required skill on the engineer's part when operating them in multiple consist.

Viewer "bill8106" very kindly comments, "I've always admired this photograph, so much is captured in it. Side-by-side comparison of an RS2 vs RS3, Alco smoke, escaping steam, Hancock whistle on 8222, gooseneck lightposts, fuel stain on 8222's cab...I can go on and on. Terrific RR photo of that era."