Modeling an SP Class F-125-1 flat car

In an earlier post, I commented on the recent Class One Model Works model of a General Steel Castings Corp. (GSC) one-piece cast body for a depressed-center flat car, and showed photographs of the prototype casting and of a completed SP car (see it at: https://modelingthesp.blogspot.com/2023/10/the-new-class-one-flat-car.html ). 

I mentioned there that Class One is offering essentially two body styles, differing in the end decks, whether they are wood or are screen over the open body casting. But Southern Pacific, as I showed in the previous post just cited, had neither style. Instead, they placed steel plate over the end areas, and also covered the transition areas between end and center decks with steel plate. I decided to see what I could do with the Class One model, and bought one. All I needed to specify was the “square” jacking pads.

The choice of railroad and car number here (SL-SF 3900), of course, is irrelevant, as I was going to modify the model and repaint. As I had surmised, it was quite easy to pop off the wood decks by inserting a razor blade under one edge and working it gently up until the attachment pegs let go.

Now I needed to add representations of the SP-applied steel plate. Below is a detail of the overhead photo from the previous post (see first paragraph, above, for link) showing half the car. It shows that the SP frame casting did not have as many holes in the center deck as the Class One model has. It also shows the minor number of tie-down holes in the end deck.

To model the sheet over the car ends, I chose Evergreen styrene sheet in the 0.005-inch thickness. I wanted the sheet to be flexible enough to readily cover the dropping transition from ends to center. I cut two pieces to the right width and length, then glued one to the end deck only, using canopy glue. (This adhesive does a great job and will not distort or attack styrene.) The idea was to let the glue cure to secure the sheet to the car end first, as at left below, so that it could later be pulled down and glued onto the transition area, as at right.

With both sheets secured, I laid out an approximate set of center lines for two groups of five holes on each end deck (see prototype photo above). I drilled them #75, intermediate between the smallest and largest holes in the prototype photo above.

At this point, I’m ready to paint and letter the car, and deal with the trucks (they are roller-bearing trucks, while SP had solid-bearing trucks). More in a future post.

Tony Thompson