SP piggyback, Part 6: trailers

This is part of an ongoing series about the beginnings of Southern Pacific piggyback service. That service on the SP began in 1953, the year I model, so I am interested in the characteristics of the operation at its outset. In previous posts, I have discussed both the highway equipment, owned by SP subsidiary Pacific Motor Trucking, and the SP flat cars that carried the trailers. The most recent of these posts, Part 5, can be found here: https://modelingthesp.blogspot.com/2025/02/sp-piggyback-part-5-3d-printed-flat-cars.html . 

In a previous post, I showed the model trailers that had received a coat of white primer (Tamiya “Fine Surface Primer”). That post is at this link: https://modelingthesp.blogspot.com/2024/10/sp-piggyback-part-4-progress-on-3d.html . My next step was to airbrush them with Daylight Orange, using the excellent Star Brand version of this color, STR-27 (I have discussed this color: https://modelingthesp.blogspot.com/2022/06/pfe-orange-one-more-time.html ). 

Since in the final paint scheme this color is only on the upper parts of the trailer, most care was taken with coverage in those areas, but each entire model truck body was painted. Otherwise there could be risk of uneven color in the coat of Daylight Red to follow, on the lower parts.  

The next step was to mask off the upper part of the trailer, using the excellent 18-mm Tamiya tape. This tape performs beautifully on the glossy surface of the orange coat, above. Then I could paint the lower body, and the underbody, Daylight Red, using Star Brand STR-34. Here the masking line will be in the upper part, above the “belt rail” on the trailer, because it will be hidden by the black stripe, as is visible seen in the prototype photo, below.

This image is repeated from a PMT history post, which can be found at: https://modelingthesp.blogspot.com/2024/09/sp-piggyback-part-1-pacific-motor.html . Background: this is a 1940s publicity photo, posed to emphasize the truck–rail connection, shown here as a box car at a freight platform (SP photo, courtesy Steve Peery). The tractor here is a GMC, typical of SP’s long closeness with Chevrolet and GMC motor vehicles, pulling a 22-foot trailer.

The lower trailer bodies, and underbodies, were airbrushed red, and of course the tires will subsequently be painted black by hand as a final painting step. Here are the trailers at this point:

I might mention that there has been some disagreement over the years as to whether the underbodies were black or red. It is a minor point, since one can’t really see the underbody of a trailer on a flat car or on the highway. But SP photos of the trailer tie-down process, several of them reproduced in Chapter 13 of my book, “Automobile Cars and  Flat Cars,” Volume 3 in the series, Southern Pacific Freight Cars (Signature Press, 2004), seem to me to show a color like the bottom section of the trailer sides. 

Lettering follows the prototype photo shown above. Luckily, a Microscale Decals set of some years ago remains in production and in stock, set MC-4027. I used those sets (each of which can do one trailer) for these models. By the way, I should mention that examination of about a dozen photos of these trailers shows all PMT 22-ft. trailer numbers in the 3100 and 3200 number series.

My decaling approach has been to first stand the trailer on its flat end, and drape over the front a piece of stripe, containing the PMT initials at center front. Once that’s well dried, I start adding all the other lettering, along with a second length of stripe around the back, and the back end lettering. Here is a prototype rear view to illustrate (SP photo). And I should mention that locations of some of the lettering varied over time and for slightly different trailer bodies.

With the entire lettering applied, one can see what an attractive paint scheme this is.

I can hardly wait to finish the flat cars and start putting these trailers onto them! Thanks one more time to A.J. Chier for creating these fine 3D-printed models.

Tony Thompson