SP piggyback, Part 3: piggyback service begins

In this series of posts, I am presenting a summary of the history of the prototype Southern Pacific piggyback equipment and associated prototype operations, along with modeling issues and opportunities. The present post is about the beginning of SP’s rail service, and as such is a kind of continuation of the first post, which was about Pacific Motor Trucking (PMT) prototype. You can read that first post at this link: https://modelingthesp.blogspot.com/2024/09/sp-piggyback-part-1-pacific-motor.html .

There is extensive photographic documentation of the beginnings of SP piggyback, and I will turn to that in a moment, but first I want to summarize the background. For this, the fundamental resource is David DeBoer’s book, Piggyback and Containers (Golden West Books, San Marino, CA, 1992). After working for the New York Central, the Federal Railroad Administration and the Interstate Commerce Commission (ICC), DeBoer moved on to Southern Pacific, advancing to VP of intermodal operations, before leaving to help found Greenbrier Intermodal. One could say that he didn’t just see intermodal happen, he had a role in directing it, and knew everybody who was anybody; that’s evident in the book.

An important point made by DeBoer is the foundation for SP President D.J. Russell deciding to initiate piggyback service. Because SP already owned a trucking subsidiary, PMT, and its busiest route, Los Angeles–San Francisco, was entirely within California, SP would not have to contend with ICC regulation. In addition, reliance on PMT meant that competing truckers could be shut out of SP’s piggyback routes.

The first challenge faced by SP, and other pioneer railroads undertaking piggyback operations, was how to secure the trailers to the flat cars. Railroaders regarded a wheeled vehicle on a flat car with considerable alarm, and wanted it secured as many ways as possible: wheel chocks, tie-down chains or cables tightened with binders, and often a last-resort “disaster cable” or chain in addition to everything else. Much of this was borrowed from the circus world, which had been tying down vehicles on flat cars for decades.

SP was very much of this “belt and suspenders” persuasion, choosing steel cables instead of chains (T&NO did use chains), with two cables and binders at each corner of each trailer. They also chose support stands underneath trailers, one at the front alongside the landing wheels, and one in front of the road wheels at the back.

All this can be seen in this end view of a newly converted Class F-70-7 flat car at Bayshore Shops in 1953 (SP photo). The cars were 53 feet, 6 inches long. Rub rails along the car sides, a bridge plate at each end, wheel chocks alongside the rub rails, and three of the four support stands erected, and some of the cable binders above the coupler and at the center and ends of the rub rail, are all visible. The boxes seen along the car center line contain cables. (There is considerably more photo coverage of the flat cars and trailer tie-downs in Chapter 13, Volume 3 of my series, Southern Pacific Freight Cars, Signature Press, 2004.)

The bridge plates were essential for what was called “circus loading,” derived directly from circus practice. Trailers had to be backed down a string of flat cars to their destination car. Needless to say, this was laborious and took careful work by drivers; and the entire process had to be repeated for unloading, though then at least drivers got to drive forward (SP photo at Los Angeles).

 

When tied down, this was quite an array of cables, two at each trailer corner, as mentioned (SP photo). Each cable had to be looped over a hook on the trailer frame, then tightened with the binders. This of course required a fair crew of groundmen, who attached and tightened all the cables.

SP inaugurated piggyback service first on T&NO on May 4, 1953, and at the end of June that year, inaugurated it also on Pacific Lines, initially only for the Los Angeles–San Francisco route. Many photos were taken of the initial service, such as this one (Joe Strapac collection).

So during the second half of 1953, SP piggyback was indeed operating on the Coast Route, and trailers moved both in some daytime trains, and were also to be inserted in the “Coast Merchandise” or Overnight trains. Here is a photo of two piggyback cars at San Luis Obispo, being switched by Consolidation 2592 (SP photo). Note the short-lived practice of “disaster bars” on rear doors.

I will continue with comments on modeling this early equipment in one or more following posts.

Tony Thompson