I am continuing with the project to complete the very nice 3D-printed Southern Pacific piggyback cars made by AJ Chier. In my last post about the flat cars, I showed completion of the body details (grab irons, sill steps, brake wheels), shown at: https://modelingthesp.blogspot.com/2025/02/sp-piggyback-part-5-3d-printed-flat-cars.html . I should repeat that because I model 1953, the first year of this service on the SP, my models reflect the very earliest practices of SP piggyback.
First I needed to prepare the models for trucks and couplers. I used a bottoming tap to tap the bolster and coupler pocket holes 2-56.
For lettering, I used the Protocraft set for SP Class F-70-6 and -7 flat cars (Rick Leach artwork). Each set is intended for lettering a single car. I used the set, but was a little disappointed in the low opacity of the white lettering in the smaller sizes. Here is the model as I lettered it with the Protocraft set.
Below is the central part of a builder photo (AC&F) of the last car in Class F-70-7 (they were numbered 140500–142549). You can readily see, in comparison to the above model photo, what I mean about the appearance of the smaller lettering (you can click to enlarge). But in layout operation, no doubt this will go unnoticed. I did omit the AC&F builder emblem, as these are not visible on any of SP’s piggyback cars.
Next I turned to installation of trucks and couplers. This involved making a styrene sheet cover plate for the coupler pocket, what’s sometimes called a “one-minute job.” Then Kadee No. 158 couplers were added.
Trucks are an interesting problem. These 70-ton flat cars of course had 70-ton trucks, and most modelers aren’t sensitive to the differences between 50-ton and 70-ton trucks: 5' 8" wheelbase instead of 5' 6", and slightly beefier sideframes; both aspects essentially invisible in HO scale. But several HO scale truck makers do offer 70-ton trucks, and I chose to use those.
The SP prototype cars had Barber S-2 trucks, of the early A0 (A zero) variety. Most commercial Barber S-2 trucks are S-2-B (so marked by the rare truck maker who actually designates such details, such as Kadee). Can we tell? Actually, yes. Below is a view (AC&F photo) of an SP Barber S-2-A0 truck.
Here you can see the distinctive Barber bolster end, with its friction-wedge corners, and a pair of truck springs outermost (there were five such springs in the spring package). For more on this, for those interested, I would direct you to Bob Karig’s superb truck chapter (Chapter 6) in Coal Cars, University of Scranton Press, 2007.
(For background, on model trucks, I recommend Richard Hendrickson’s HO scale truck document, available on Google Docs at this link: https://docs.google.com/file/d/0Bz_ctrHrDz4wcjJWcENpaDJYbUU/edit?usp=sharing .)
Commercial HO scale trucks, such as the very nice Kadee 70-ton Barber S-2-B, are visibly different, having three outermost springs visible in the spring package, a very noticeable aspect of a truck. I show the Kadee S-2-B below.
I chose the Rapido 70-ton truck (no. 102059), which does have the Barber bolster end and a pair of outermost springs, thus looking like the SP Barber trucks. You could also use the ExactRail 50-ton Barber, which is close to the SP prototype.
The completed flat car is shown below, loaded with a pair of the Pacific Motor Trucking trailers, which I described in the previous post (available at this link: https://modelingthesp.blogspot.com/2025/05/sp-piggyback-part-6-trailers.html ).
I look forward to seeing this car in a mainline train during a layout operating session, a single car being appropriate in the earliest days of SP piggyback. And thanks, one more time, to AJ Chier for making these very nice 3D printed models.
Tony Thompson
No comments:
Post a Comment