I found this Alco in Beatrice, NE today. I’m not sure if it is an S-1 or a S-2? I love Alcos (even though most of them were sent to scrap yard before I was born). Its nice to see a few of them still in running order. This one looked to be owned by the local coop to move hoppers around when they come in. There was an EMD unit (SW-1500 maybe?) there as well.
Awkward angle to tell. The most visible difference is the S-1 has a radiator grill taller than it is wide, the S-2 is square (same height as the S-1, but longer, for more cooling capacity for the more powerful prime mover). Actually, that’s either an S-3 or S-4, the difference being the trucks.
FOund another picture of it, it’s an S-3: 
–Randy
That blue engine is an Alco S-3. The small radiator shutters and the ARR switcher trucks give it away. The S-1 would have ‘Blunt’ switcher trucks. The red engine is an EMD - not a SW1500, but maybe a SW7, SW9, or SW1200. The EMD switchers changed very little in the 50’s and early 60’s.
Jim
You can’t always tell from the trucks. Yes, S-1/2 locomotives were built with Blunt trucks, and when production shifted to the AAR type trucks, the loco designation changed to S-3/4. And, the earlier post explaining the size of the radiator housing as a spotting feature between the 660 hp S-1/3 and the 1000 hp S-2/4 is right on. However, subsequent modifications by the owner railroads could have resulted in AAR trucks under a S-1 or Blunts under a S-3. However, I’m pretty sure the rounded cab windows with gaskets were a late design feature that came along after the switch to S-3 models, so that’s what I say it is. If the loco still had its builders plate, you could look at the build date. The switch from S-1 to S-3 occurred in early 1950.
A very cool little engine. Wish I lived closer to Nebraska so I could see it run.
Tom
There’s a sweet-running S-1 still earning her keep in Schenley, PA.
Here’s some more info on the line: Kiski Junction
Wayne
Assuming that the ALCO unit is riding on its production trucks this is an S-3 distinguished by, as has been pointed out, the smaller radiator; it also has a round based exhaust stack . . . . . were that stack elongated it would be identifiable as an S-2 or S-4 carbody.
The EMD carbody is, most likely, either an SW9 or SW1200. It could be an SW7–they had essentially the same carbody–but if memory serves me at least some of the earliest SW7s came equipped with engine access doors with a split louvers design.
WHy do you say Kiski 7135 is an S-3 and not an S-1? It has Blunt trucks, not AAR.
Plus the railroad’s own web site has the history of it, built in 1943 for the Navy. Definitely an S-1.
–Randy
HUH!!!
You must be seeing responses on your forum that are not showing up on mine! Where did you see anyone identifying Kiski 7135 as an S-3?; unless, as I stated in my posting identifying RE707 as an S-3, it has had a truck swap then those Blunt trucks clearly identify it as an S-1.
Incidently the accompanying photograph shows the unit to have been kept in pretty good shape but unless the owning company has kept a unit or two on hand for cannibalization parts could be becoming pretty scarce and I wouldn’t make book on how much longer this unit will last. If, as you state, it was manufactured in 1943, then it’s just a hair younger than I am . . . . . . . . . . and I ain’t exactly sure how long I’m going to last. Heck, I no longer wait for my nervous breakdowns to just happen . . . . . . . . . I schedule them . . . . . . . . . . on the 14th of each month . . . . . . . . . .
Order of posts I guess. Immediately under Dr. Wayne’s post of Kiski 7135 is your message saying “that Alco unit” without specifying the OP’s photo or Dr. Wayne’s.
RCT&HS has Reading 103, an NW2 built in 1947 that is still in excellent operating condition, and so far no one’s cannibilized parts off other units (unless previous owners did) to keep it so. Recent work included fabricating a new pipe for the cab heater (old oen was completely rusted away) and a complete rewiring of the controller and contactors. Still she soldiers on, pretty mucht he only fully operational piece of equipment on the property so if cars need to be shifted, 103 gets the call. Last year 103 hauled multiple round trips for the annual open house, although the big Alco C630 5308 pulled the train in one direction (ran as a push-pull). Tough little loco. I suspect Kiski has a capable shop. Local carrier Dleawar Lackawanna is almost all Alco, with locos varying from S-1’s to RS-3’s to MW636’s. Anyone wanting an Alco repaired usually contracts their shops.
–Randy
S1 and S3: Narrow radiator panels, no turbocharger, conical stack (sometimes called a ‘funnel-shaped’ stack).
S2 and early S4: Wide radiator panels, turbocharger, jug-shaped stack.
S1 and S2: Blunt trucks.
S-3 and S-4: AAR trucks.
Blunt trucks were expensive to maintain, so some railways replaced them with AAR trucks. I’m not certain that this was done with any S-1s, but I know for sure that CP refitted some of their S-2s with AAR trucks.
Early S-1s and S-2s did not come with exhaust stacks, so some railways put straight pipes on S-1s and rectangular stacks on S-2s.
Late model S-4s had welded carbodies and rectangular stacks with an oval base.