Southern Pacific was one of the best customer for the Alco (American Locomotive Company) diesel switcher. This began during World War II, when the War Production Board dictated which diesel models each manufacturer could produce, and how many. GM’s Electro-Motive Division (EMD) was restricted to production of FT road diesels, and Alco to the production of diesel switchers. SP, needing all the switchers it could get, obtaining 57 of them during 1942-44.
After the war, EMD prioritized building road diesels (F3 and F7 models), and deliveries of their switchers had long lead times. Again, SP continued to purchase Alco switchers because they could be delivered sooner, even though they would have preferred the EMD models. Their fleet of Alco S-2 models, beginning with the 57 mentioned above, grew to 122 by 1950.
(For a thorough history of all the Alco switchers that SP owned, I recommend Joe Strapac’s Volume 18 in his magisterial series, Southern Pacific Historic Diesels, Shade Tree Books, 2013. I will freely quote from his information in this post.)
The Alco S-2 was a 1000-horsepower locomotive with sturdy General Electric traction motors. One of its distinctive spotting features was the truck design used, a proprietary one known as Blunt. Many Alco customers believed this truck to be superior on rough or degraded track. But others were bothered by the differences from the so-called “AAR switcher truck” used by other builders, and eventually Alco agreed with AAR requests and replaced the Blunt trucks with the General Steel Castings version of the AAR switcher truck.
Below is a nice in-service sot of an Alco S-2 at Ogden in September 1952 (Wilbur C. Whittaker photo). I should mention that this is a slightly oddball S-2, in that it is one of only a few S-2 engines built in 1944 that had horizontal radiator shutters at the front. Otherwise it’s a good view of the right side of an S-2. This is, of course, the famous “Tiger Stripe” scheme of orange stripes on a black body.
For a good view of the left side of an S-2, and to show some other details, I include below a color view taken in San Francisco on June 20, 1957. (Dave Sweetland photo, Al Chione collection). The white portions of the handrails are evident, as is the tan canvas sun shade on the cab. This engine has vertical radiator shutters, as did nearly all S-2 models. Incidentally, the “radio-equipped” lettering on the cab side arrived in the mid-1950s, after my 1953 modeling era.
To model these very numerous switchers on the SP, I chose SP 1389, a switcher assigned to Coast Division in July 1952. My model is an Atlas Model Railroad Co. product from before the days of DCC. I made a few modifications to the stock model, painted and lettered it, and wrote an article for Railroad Model Craftsman magazine about the project (the issue of May 1988, page 54 to 57). More recently, a decoder and sound have been added. Here is a photo of this model.
The Alco replacement for the Model S-2 was the Model S-4. It was in most respects identical to the S-2, but had AAR switcher trucks. Cab and body were still riveted construction, and many details were identical to the S-2. Below is an Alco builder photo from November 1951, of part of an order delivered to SP that year. In contrast to the 122 S-2s on SP, there would eventually be 64 S-4s purchased.
For models, Atlas has just recently released a run of Alco S-4s including the SP Tiger Stripe version. I signed up for one, and nowadays, of course, it comes with DCC and sound. I simply added a coat of flat finish and used acrylic washes to tone down the paint (and to darken the stack). Here’s the engine spotting up a freshly loaded car to be iced, in my town of Shumala.
These are interesting switchers and an integral part of SP locomotive history in the transition era. I’m glad to add an S-4 to my switcher fleet, and look forward to its use in my next operating session.