Tuesday, May 27, 2014

Modeling pre-war SP 50-foot automobile cars

At various times, Southern Pacific purchased groups of automobile cars (defined by the AAR prior to 1954 as box cars with double doors). The cars built before 1936 were single-sheathed and are quite varied and interesting, but I won’t touch on them in this post. The cars purchased after World War II pose some intriguing modeling challenges, and I have a project underway to model one such car, which I will report on presently. That brings me to today’s post, which is about the cars built after 1936 and before World War II.
     There were two classes of 50-foot cars purchased in this period, classes A-50-12 and A-50-14. The latter class has been offered by Proto2000 in an almost exact model, so I won’t say much more about modeling it. Instead, I will discuss the modeling of Class A-50-12, and highlight some of the differences between that class and the -14s.
     First, let me show the goal. This is a General American builder photo of Class A-50-12, from the SP collection at Stanford University.

Now let’s explore the characteristics of this car, compared to its sister class, Class A-50-14.
     Class A-50-14 had a straight-panel roof with 13 raised panels, along with a smooth panel at each end to accommodate the lateral running boards. They also had what I call 4 + 6-panel sides, meaning four panels to the left of the double doors, and six to the right, and full-length straight side sills. In all these respects. the -14 cars were the same as the A-50-12. But the -14 ends were the standard late-1930s Dreadnaught ends with W-corner posts, making the edge rounded, while the -12s had sharp-cornered Dreadnaught ends. The ends, then, are the most visible difference between -12 and -14.
     From a modeling perspective, both of these SP classes differ from the old Athearn 50-foot automobile car, which accordingly was never close to accurate for either an SP Class A-50-12  or -14 auto car. Athearn models of that era had several other shortcomings, which I will come back to in a moment.
     But as I said, the Proto2000 model makes any thought of serious surgery to model the A-50-14 on an Athearn 50-foot body evaporate and fly quickly away. That leaves the problem of the A-50-12 cars. Their most visible difference from the -14 cars was the sharp-cornered Dreadnaught end. The Athearn model does have a sharp-corner end (though in 5/5 instead of 4/5 configuration), but its incorrect roof (12 instead of 13 raised panels), wrong number of side panels (5 + 7), and numerous clunky details such as cast-on ladders, oversize sill steps, and too-short doors, mean that it really is not reasonable to think about surgery to make an A-50-12, either.
     My furthest effort on one of the Athearn bodies involved adding a styrene strip to simulate a straight side sill, cutting off the “door claws,” as they are called, extending the brake step and adding brake step supports, installing wire grab irons, and a new running board with grab irons on the lateral running boards. This is still not very correct; for example, the doors remain too short. Here is one car I did that way, certainly a stand-in at best.

     There is a good model out there, the Sunshine kit for the A-50-12, kit no. 83.1. It is correct in all the ways mentioned above (roof, ends, doors, side panels) and has free-standing details such as ladders, grab irons, and sill steps, along with correct doors. Luckily I obtained one while Sunshine kits were still available, and Dennis Williams built the basic car for me.
     I wanted to model a car in auto parts service, and chose to replace the kit brake wheel with a better Ajax brake wheel part, so then I needed to find which A-50-12 cars that had Ajax brake gear were also in auto parts service (AAR type XAP). These should probably fall within the number series 64525–64924, which contained the largest number of auto parts cars and which also had Ajax brakes. There were about 65 cars in that group assigned to such service in 1953, the year I model, so I chose my car number accordingly for decaling. The number 64826 was indeed an XAP car in 1953, and that number can be decaled in just two parts from the Sunshine decal sheet.
     How do I know these facts? The specialty equipment applied to these car classes, and many others, are listed in Volume 3 of my series, Southern Pacific Freight Cars, covering automobile and flat cars (Signature Press, 2004, currently out of stock though readily available used). And the information on car assignments is in the Official Railway Equipment Register or ORER, or 1953, For more information on using the latter, see my post at: http://modelingthesp.blogspot.com/2014/05/the-equipment-register-part-1.html .
     I also added a styrene route card board on the right-hand door on each side. These boards are essential. The dimensions of the boards were standard, and I have shown the AAR drawing in a previous post (you can see it at this link: http://modelingthesp.blogspot.com/2012/01/route-cards-7.html ). A piece of Evergreen scale 1 x 6-inch strip, 10 scale inches long, does the job.
     The kit decals are largely very nice and are accurate, including the trust stencil that SP applied to the side sill just beyond the end of the lower door track (you can see it in the protoytpe photo above). The decals also include your choice of door symbols for either auto racks or auto parts (I chose the latter for my XAP car.) But it does not include the lettering SP applied on the bottom rib of each end, “BOLSTER SNUBBER SPRINGS.” That legend is included in my SP Tank Car decal set, available from Jerry Glow, and I added it to my model.
     I also chose a pretty recent reweigh date (for my layout year of 1953). Cars in auto parts service had new parts racks installed every year in this era, and accordingly would almost always display a reweigh date less than a year old. Here the car is in an eastward train at Shumala.

This car is a welcome addition to any cut of auto parts cars in the manifest trains for my SP main line, and joins a couple of the fine Proto2000 models of Class A-50-14 as well as several models of foreign automobile cars.
Tony Thompson


  1. Is Jerry Glow still in business, Tony? I've tried three times in as many weeks to order your tank car and also helium car decals from him, but have received no reply.

  2. I have a half dozen of the P2K A-50-14 kits in my stash. I probably don't need all 6 as A-50-14s. I probably should build some as A-50-12s. Do you think the ends from the Intermountain "1937 AAR 40' Boxcar" (P40700-13 or P40700-63) would work? The instruction sheet for the model says:

    "Thousands of these cars were built to this design for many railroads using wooden running boards, Murphy roof, 4-5 Dreadnaught ends, rivet construction and square corner post design."

  3. Yes, although the 1937 AAR standard cars were just 10 feet high inside, while the SP auto cars of both classes A-50-12 and -14 were 10 feet, 4 inches. They still had 4/5 ends, but with a taller blank area at the top. I guess you would have to splice in a piece of styrene to make the height match.

    And you're right about the numbers. There were only 500 cars of Class A-50-14, against 1325 cars in A-50-12.
    Tony Thompson

  4. I think I can cut and splice in a 4" (plus kerf) section of styrene into the top. Now to see if Intermountain has the ends in stock!