Wednesday, May 4, 2011

SP steam power in the early 1950s

As a follow-up to my post on “Choosing a 1953 locomotive roster” (here’s a link:, I thought it might be of interest to show information for other parts of the Southern Pacific system (Pacific Lines) to illustrate how unevenly steam and diesel locomotives were assigned across divisions, during the transition era.
     The data I show below are from the SP Locomotive Assignments brochure dated June 30, 1951, which I examined at the Library of the California State Railroad Museum (CSRM) last week. It’s among very many SP documents and records amongst their holdings. I haven’t reproduced the data for all divisions, but have chosen what I thought were the interesting parts of the information. An explanatory note: by “Diesel freight,” they meant road diesels of 5000 or less horsepower, such as the Baldwin AS-616. By “Diesel 6000 hp” they meant A-B-B-A sets of F7 units.

It is striking that the Salt Lake and Los Angeles divisions had the lion’s share of the F-unit sets, and that the three biggest California divisions had the bulk of the steam power. Diesel switchers were very unevenly assigned as well. I combined the Tucson and Rio Grande divisions because they were about equally provided with each type of power.
     In my previous post on this topic, I only wrote about the Coast Division (which had 121 steam locomotives assigned on July 1, 1952, versus the 147 listed above for June 30, 1951). I also looked ahead in time to January 1, 1953, and at that time the Coast Division actually had a few more steam engines, 124.
     One point to be drawn from these data, I suppose, is that in the transition era on the SP, how one chooses the balance between steam and diesel power, and which classes of steam or diesel engines to model, depends very strongly on the time chosen to model, and of course on the particular division.
     Now of course I realize that there are modelers who will tell you that they “model the 1950s” or even that they “model the early 1950s.” If one actually wants to model realistically (a big assumption), such a broad choice of modeling era simply isn’t an option. I made the same point in my article in Railroad Model Craftsman about reweigh dates for freight cars (for a corrected version, see And if you research a variety of eras, you will find that this conclusion can be drawn for most of them, not just for the early 1950s: a great deal was changing over a span of years, and juggling all of it simply can’t be realistic.
     There’s a philosophical point to be made here, which I’ll state briefly. I do recognize that everyone pursues their hobby in their own way, and having fun any way you want to have fun, is entirely the point of a hobby. I have no wish to criticize anyone’s choice of how to approach this or any hobby.
     But I would just take the position, well articulated by Tony Koester among others, that we can reasonably separate the hobby of “model railroading,” in which real railroad equipment, practices, places and operations are modeled, from the hobby of  “playing with model trains.” If you aim at the former hobby instead of the latter, I cannot make a stronger point than Mr. Koester has done: “You cannot hide behind the oft-heard mantra that ‘It’s my railroad, and I can do anything I want!’ No, you can’t – not if your goal is to convince the viewer, not to mention yourself, that you’ve done a credible job of depicting a specific place and time.”
     ’Nuf said.
Tony Thompson


  1. Well stated Tony!
    With the use of ten years worth of Sanborn maps, I was able to finally identify all of the building in existence on Sahwatch St. to day. I know at least have an idea of what will line both sides of my layout. So with the knowledge of the locomotives, the proper cars and now the buildings, I think that the data is coming together to model a very creditable version of the Sahwatch St yard when the switching was done by the Colorado Midland under contract to the Union Pacific Denver & Gulf in 1895. While it's not the SP in 1953, I want to thank you for developing a darn good process model for making good decisions in developing a creditable layout.

    Tom VanWormer
    Monument CO

  2. I must confess that I'm one of those who say I'm modeling the SP in the early 50s and the only reason I say that is that I simply don't know enough about the SP in the 1950s to pick a specific year. I really don't know the difference between 1950 and 1952 on the SP. As it is, it's taken me 2 years to narrow it down to the early 50s.

    Certainly not helping is the fact that for those of us who live far away from the vasts sources of information on the SP, we must rely solely on books and articles for our information. Now if I wanted to model the L&N or CSX, I'd have it made.

    The good thing is that with the information available in your books, articles, and online such as this blog, I'm "aiming for the former hobby" and getting much closer to picking a specific year.

    Thank you,Tony.

    George Corral
    La Grange, KY

  3. When I first looked at the June 30, 1951 listing of motive power assignments, I was a bit puzzled why only 15 passenger diesels were shown. At that point in time, SP had 15 E7's, an E8, and the three ex-joint service E units for a total of 19 E's. Add to this the 24 early PA/PB units, which included 16 A's and 8 B's by this date, and it is clear that the diesels listed as passenger in this list are really sets of units and not units. The passenger diesel assignments of 7 for the L.A. Division is probably all 19 E units. This would be six 3-units sets plus a spare unit (the E8A) or 5 three unit sets and two 2-unit sets The 8 units for the Western Division would be the eight 3-unit sets of PA/PB's. Now the numbers make more sense.


  4. To George and Tom, you're most welcome, and I'm glad the posts are informative and helpful. That was my goal.

    Greg, I'm sure you're right about the "passenger diesel" listing, and note that it matches the reporting style of the "Diesel 6000 hp" locomotives, that is, by lumping together individual units into "locomotive" sets. Your reconstruction of the likely components of the passenger sets seems reasonable to me. I confess I never thought to look up a comparison of the actual diesel passenger units on the property, vs. the 1951 listing. So your clarification is welcome.
    Tony Thompson