Alco RS type locomotive

Model Railroader Prototype information for the modeler
1

Could andbody tell me what the RS stands for in Alco RS type locomotives[?] I kinda thought Road Switcher, but I wasn’t sure.

thanks in advance,
Noah[:p][:)][:p]

2

Correct; Alco call thier switchers S-; 4 axle road switchers RS-__; cab freight units: FA- and FB-; cab passenger: PA and PB_.

I don’t know what the C and D in RSC and RSD stood for.

3

RSD and RSC=six axles.

4

I think the C in RSC means an unpowered axle.

5

I think you’re right.

6

Yes, RSs were 2 axle trucks, both axles powered. RSCs had 3 axle trucks with an unpowered middle axle. And RSDs were 3 axle trucks, all axles powered, and the middle one was offset slightly.

—jps

7

Interesting tidbits:

Alco didn’t refer to their offerings as FA’s, PA’s, and RSD’s initially; they used their own scheme such as DL600-B (the RSD-15). The railfans used the clearer scheme so much that they ended up adopting it.

In deisel engine terms, A, B, & C are supposed to refer to the powered axles in the trucks, so that a B-B locomotive has two trucks with two powered axles in each, while A-1-A - A-1-A would designate an engine riding on six axles total, with each truck having a powered axle (A) on either side of an unpowered (1) axle. The C-C arrangement is supposed to denote an engine riding on six axles, with three powered axles in each truck.

So, the RSC’s are an anomaly because the C denotes the unit with an unpowered third axle in each truck, contrary to the above. One might reasonably expect the whole situation to be backwards of what it is, with the RSC’s being the all-powered-axles version.

8

Actually, the axles toward the center of the locomotive where offset away from the middle one compared to the RSC truck. The spacing between the center axle, and the one closest to each end of the locomotive is the same on the RSC3 and RSD4/5. Which lead to the possiblity of bashing some RSC3 trucks from RSD trucks…