Saturday, March 2, 2019

How were SP branch lines operated?

I am interested in how branch lines were operated (my personal era being the transition era), because my layout is predominantly a Southern Pacific branch off the Coast Division main line. There isn’t much traffic on the branch, so it is served by one or two local trains a day. It does not have any scheduled trains, in common with most SP branches, as shown in division timetables.
     Recently an acquaintance (who shall remain nameless) said to me in a firm voice, “SP branches were operated under yard limit rules.” That means Rule 93. I was surprised at the generalization in the statement, but realized I didn’t know whether it was true for any branch lines, or true for some, or true for all. I first thought to check my 1955-edition SP rule book, and it simply gives a pretty standard version of Rule 93. There is no mention of branch lines. Here is the rule book statement:


     This is subject to Rule 81 or Rule 513, which are similar rules; Rule 513 is for operation in Automatic Block Signal territory. Rule 81 is the foundation of train movement rules. You can see below that it is the first rule in that section of the rule book.


     As I suspected from the start, the operation of branch lines would be spelled out, not in the rule book for the entire railroad, but separately for each division. And this might or might not be included in employee timetables for a particular division, but would certainly be included, if in force, in division Special Instructions publications. Here is an example of one of these, dated 1953, which were (as I understand it) issued in concert with new timetables, but only whenever revisions were made.


     Looking through lots of these for SP Pacific Lines divisions, my conclusion is that although a number of SP branches were indeed operated under yard limits, most were not, including some pretty long ones and a few rather short ones. (For example, the Kentucky House, Friant, Schellville, Oakdale and Ione branches, all quite long, were not in yard limits.) But although yard limits for each subdivision are spelled out in the Special Instructions only, they are always visible also in the timetable. Here is an example from Coast Division, the San Bruno Branch.


This branch left the main line essentially at San Francisco Yard (usually called Bayshore) and was entirely in yard limits; note along the left edge of the timetable that the yard limits are shown.
     Some well-known and busy branches were also operated under yard limits, such as the Arvin Branch. Like San Bruno, it was very near a major yard (Bakersfield), and here is its timetable listing.


Here again, the extreme left edge of the timetable shows the extent of yard limits. 
     So anyone with access to an employee timetable can readily determine which, if any, branches on a particular division were operated under yard limit rules, in the way shown above. But the Special Instructions also indicate all yard limits on each subdivision, under a Rule 93 heading. For the Guadalupe Subdivision of Coast Division, within which my layout is situated, here is the listing:


Note that the Lompoc Branch is listed, but that only 0.35 miles of the branch beyond its mainline junction at Surf is indicated. This of course permits switching at Surf and use of the branch switch, without entering the branch outside yard limit rules.
     I conclude that my mythical Santa Rosalia Branch would likely not have been operated under yard limit rules, and train orders and clearances need to be issued to branchline trains for authority to operate. I do have SP-origin forms for both clearance cards and for train orders (see my description at: https://modelingthesp.blogspot.com/2012/09/modeling-sp-train-orders.html ), so am ready to proceed.
Tony Thompson

11 comments:

  1. Thanks for this informative post, Tony. I suspect that one of the challenges with the general statement is how the railroad would define a branch line. Of course, if it was defined as a length stub-ended length of track that was operated under Rule 93 then your friend would be right :-).

    On a related note, do you have any knowledge about how clearances worked for trains entering and leaving SP branches?

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  2. I assume that a clearance card was issued to a crew departing onto a branch, along with their order(s). The clearance is a way to verify that all relevant orders have been delivered, so I assume it would be used.
    Tony Thompson

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  3. A general comment about clearances and TO's (i.e. it is not specific to SP):
    TO's are issued to protect a train for it's ENTIRE run across a subdivision; they are not issued piecemeal. In other words, at the originating terminal (A), the train is given orders that protect it for its entire run from A-Z; it does NOT get orders from A-C, then at C it receives orders from C-M, and then at M receives orders from M-Z. So, if a train went from San Luis Obispo (SLO) to Shumala, and thence up the branch to Santa Rosalia, it would get orders at SLO getting it from SLO all the way to Santa Rosalia.
    Second, a Clearance is given at the initial terminal for a train (whether there are many TO's or none), and at any intermediate TO office at which the TO signal is set to "Stop" (again, whether there are many TO's or none). [Generally, the TO signal is set to "Stop" because there are orders for the train].

    Regards,

    -Jeff

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    1. I would offer full agreement with your comments, Jeff. If I had room to model San Luis Obispo, as on my original layout, I would probably originate trains for my branch at San Luis, and as you say, issue orders and clearance for the whole trip.

      Instead, I operate the branch as SP did with a number of its branches, namely with trains operating just on the branch, not on the main. And since we just operate a branchline train, it gets a clearance just for the branch.
      Tony Thompson

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  4. Which direction is superior on the SP? I think the branch runs eastward from Shumala, right? On the UP, there was an analogous eastward branch, and the timetable stated that "Westward trains are superior to trains of the same class in the opposite direction." This caused a problem. On the branch, there was one train which ran out and back each day. The timetable showed these as #172 (the outbound) and #171 (the return). But since #171 was in the superior direction, if #172 (the outbound) was sufficiently late, it would have to protect itself against #171. But obviously, #171 wasn't coming, because it was the same engine and same crew. So you'd have to sit forever and wait for yourself! The solution: a special rule that says that #172 was superior to #171. One could also have a special rule saying that Eastward trains are superior on the branch. A third option is to have the two trains be of different Classes.

    Regards,

    -Jeff

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    1. Good points, Jeff. Westward was superior to eastward on the SP. As you say, trains departing up my branch from Shumala are heading railroad east, though geographically west. I have not worried (yet) about superiority on the branch, because (so far) I only send one train at a time.
      Tony Thompson

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  5. Tony, very interesting branch line operations discussion. Are you considering having more than one train at a time on the Santa Rosalia Branch? Maybe a Doodlebug or equivalent that would occasionally run between Shumala and Santa Rosalia that the freight has to clear up for? A register at Shumala? Train Orders for the freight?

    Al Daumann

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    1. Yes, I have thought of a number of ways to insert a second train on the branch. SP had ended its use of doodlebugs by 1953, but railfan excursions were beginning to be widespread, and I could run a short passenger special under that concept. Could definitely be fun operationally: meet at Ballard, maybe run engine around train at Santa Rosalia, etc.
      Tony Thompson

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  6. I'm quite new to this aspect of things, but it was a very interesting read. As I'm toying with the idea of a fictitious Coast Line branch myself inspired by the Ojai Branch, I took a look in my 1956 LA Division timetable to check the Ojai Branch out, and noticed that only Ventura Junction is within yard limits (of Ventura yard), but Ojai is not.

    This got me thinking: the Arvin Branch table you show above shows that branch as being 16.5 miles long, and all in yard limits; the Ojai Branch, however, is only 15.0 miles long, but not within the limits of Ventura yard...

    So then I looked at the others in my TT, and found:

    1. the main of the Firestone Park Sub is 5.8 miles, all in yard limits;
    2. Pasadena Branch, 4.8 miles - only Alhambra within yard limits of LA Yard
    3. San Pedro Branch, 16.4 miles, 16.4 miles - Firestone Park to South Gate (1.2 mi) within yard limits (of Firestone Park?), and Thenard Tower to San Pedro (4.5 mi) within yard limits (of... see *);
    4. Long Beach Branch, 2.1 miles, all in yard limits (of... see *)

    * the junction point of the Long Beach Branch is Wilmington Anaheim Blvd, which is within the Thenard Tower-San Pedro section of the San Pedro Branch indicated as being in yard limits; I imagine this means that the entirety of the Long Beach Branch falls within these same yard limits. But is that San Pedro, or Long Beach? This is just an aside, interesting, but unrelated to my question...

    ...judging from the above, it's clear route length is not what determined whether the entirety of a branch line is operated under yard limit rules or not. So then, what *was* the reasoning used in determining which branch (or portion thereof) was operated under yard limit rules, and which was not?

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  7. I had also noticed that length was not the key. I assume these decisions on yard limits were driven by crew convenience and safety. It might be difficult at this remove in time to try and re-analyze such matters.
    Tony Thompson

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  8. Thanks for the reply. I noticed that you'd opted not to operate the Santa Rosalia Branch under yard limit rules, and since my inspiration Ojai Branch was the same, I'll likely go with the same solution for my own imaginary branch.

    Though a further comment, I had the sudden thought that maybe traffic levels might have had something to do with it: there are branches not using yard limit rules with extras only and no scheduled trains (e.g. Ojai, Burbank, Santa Paula, Pasadena), and the Firestone Park Sub line does use yard limit rules and does have scheduled trains. But then I noticed that the San Pedro Branch does have scheduled trains, but doesn't use yard limit rules over the entire line... I'm not familiar with these lines at all, but if I recall correctly Van Nuys (on the Burbank Branch) was a pretty busy spot, so I suppose I'm back at zero. In any case it doesn't matter that much, just another side musing.

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