Southern Pacific steam switchers

Like most railroads, Southern Pacific in steam days owned a considerable fleet of switchers, very predominantly of the 0-6-0 wheel arrangement. And as with most of the SP steam locomotive roster, many were built by Baldwin, others by Alco and Lima, but a notable class of relatively modern switchers was built in SP’s own shops, 38 locomotives in switcher class S-12. Many of these survived to the end of steam. I’ve been meaning for some time to summarize the SP fleet as it was in later days.

Like other steam locomotives in the early days, SP switchers originally all had slide-valve cylinders, limiting the boiler pressure and thus the tractive effort which they could use. These older switchers also were frequently equipped with what are often called “slope-back” tenders and inside valve gear. Below is an example from Class S-8, built by Alco-Brooks in 1908 (Wilbur C. Whittaker collection, location unknown). 

But in the summer of 1913, SP began to acquire switchers in new Class S-10 with piston valves, a modern feature in use with SP road locomotives since at least as early as 1900. Engines in the S-10 class were built by Baldwin; following Class S-11 came from Lima. They were succeeded by the SP-built Class S-12 mentioned above, from the summer of 1918 to the summer of 1923, 33 of them built at Sacramento and the other five at Los Angeles General Shops.

Many of the Class S-12 locomotives were equipped with newly-built cylindrical tenders, like the one shown below (Paul Jansen photo at Bayshore, Clark Bauer collection). Long called “sausage tenders” by SP enthusiasts, they were modified after construction with the very tall oil hatch visible here. Note also that the road name lettering is entirely located on the water tank, avoiding the inevitable oil spills on the forward fuel tank.

The earliest versions of this tender design had a 4700-gallon water capacity and were classed accordingly as Class 47-C (C = cylindrical). Soon the design was enlarged to 5200 gallons, Class 52-C (taller and 3 feet longer), for most of the Class S-12 engines. The car shown above is a Class 52-C tender.

Other locomotives of Class S-12, along with those of other classes, were also equipped at times with tenders from older locomotives, suitably modified. By that, I mean changes such as cutting away the projecting sides of the oil bunkers on conventional Vanderbilt tenders for better rearward visibility. The need to do so can be visualized, looking at the Class 70-C tender shown below (behind 4-8-0 no. 2919; Joe Strapac collection).

When one of these 7000-gallon tenders was modified in this way, it looked like the photo below (Gene Deimling collection), and is sometimes called a “clear-vision” tender. (You can click on the image to enlarge it if you wish.) The switcher is from Class S-12. Incidentally, steam locomotive range was entirely a function of tender water capacity, not fuel, so reducing the fuel bunker somewhat did not limit the locomotive.

So if a person were to model a Southern Pacific steam switcher, and do so for the period after World War II, the largest class with piston valves would be the best choice. That class is Class S-12, which has the additional attraction of having been built in the railroad’s own shops.

For much more about SP steam switchers, particularly photographs, the indispensable book is this one by Gene Deimling. It was published by Benchmark Publications, Los Altos, CA, 1987.

In addition, there are other helpful references:

Diebert, Timothy S. and Joseph A. Strapac, Southern Pacific Company Steam Locomotive Compendium, Shade Tree Books, Huntington Beach, CA, 1987.

 Wright, Richard K., Editor, Southern Pacific Company Diagrams of Locomotives and Tenders, Wright Enterprises, Oakhurst, CA 1973.

I am still contemplating a modeling exercise aimed at one of these locomotives, but have been exploring options.

Tony Thompson

Waybills, Part 118: more information

For a number of years now, I have been writing occasional posts in this blog about both information and issues relating to waybills, in both prototype and model form. (To find previous ones, use “waybills” as a search term in the search box at right.) A recent example was this one: https://modelingthesp.blogspot.com/2024/04/waybills-part-114-managing-fleet.html . This may be a daunting backlog; a guide to the first 100 of these posts is here: https://modelingthesp.blogspot.com/2022/11/waybills-part-100-guide.html .

Today I want to share yet another source of prototype information on this topic. A single example is shown below. This was part of an approximately annual issue of “question and answer” format from the journal, Traffic World, and was issued by the publisher of Traffic World, the Traffic Services Corp., in Washington, D.C. The magazine was published from 1907 until 2011 or thereabouts.

This is a 6 x 9-inch book, hardbound, and contains 155 pages. The points made in it stem from question-answer pairs in the magazine between July 1964 and June 1965, and it was issued in 1965. How long these volumes continued to be published, I don’t know, but at least until 1976.

Many of the questions, it must be said, relate to minutiae of the rules, and often turn on extremely microscopic examination of Interstate Commerce Commission rules and other authorities of a legalistic bent. Those, naturally, make extremely dry reading, and might be ideal for perusal when you are having trouble getting to sleep.

But there are nevertheless gems in here. Here’s one that isn’t too long or too detailed (adjacent material was removed from the page to focus attention on the point I want to discuss). I will comment below. You can click on the image to enlarge it, to help read the text. The topic is routing.

This example makes very clear that priority in routing lies with the shipper, even if that route results in higher rates than some other route. But it also makes the interesting point that if the shipper has not designated the route, the railroad is obliged to route via the route of lowest rate. 

It is long-established dogma among modelers that the railroad would route a car so as to traverse company rails as far as possible, and no doubt that was the desire; but such routing must not be at a higher rate than another approved routing, even if resulting in lower mileage on the originating railroad.

Here is another example, this one unfortunately longer, and again, I will comment below. This entry extends over two pages, but a lot of it is citations of authorities, which can be skipped for our purposes. It has to do with leased cars.

The key point in this question runs from the bottom paragraph in the first column, to the completion of that paragraph in the second column. In essence, it asks whether an empty specialized or leased car, moving under a car order to return it to a shipping point, generates demurrage before actually being placed for loading at the shipper. Evidently the railroad involved said yes, and the shipper said no.

The answer is interesting, as it reminds us of the railroad distinction between “actual placement,” that is, the car placed at the shipper’s dock or loading door, and “constructive placement,” meaning the car is nearby in the same town on a track that can be considered an “off-spot” (for example, if there is no space at the shipper’s dock). If the latter, the railroad must furnish the shipper with notice of the constructive placement. Otherwise, there is no demurrage.

I don't see simple ways these points could be utilized during a model railroad operating session, but they do suggest things to keep in mind for such aspects as waybill contents, for example with routing. There are so many prototype examples of indirect routing that it might be considered commonplace. And the railroad would try hard to avoid off-spots, certainly not accepting them for “crew convenience.” Those are things we can keep in mind when striving for realistic operation.

Tony Thompson