Wednesday, August 19, 2015

Next 3d Freight Car Model: Southern Pacific's "Battleship" Gondolas

Boy, I've been awfully quiet lately; I'll put at least some of the blame on that 3d printer. Just to show I'm not goofing off, I'll show some of the latest work.

Here's the latest result: Southern Pacific's "Battleship" gondolas. The "battleships" were side-dump ballast cars built around 1902, and they're cool cars from so many different angles.

The Battleships are interesting construction-wise because they're some of the Southern Pacific's early steel freight cars, completely built using steel plate and angles, riveted together. They're sort of like the Eiffel Tower of freight cars in that way - big, metal, and covered in rivets, and they probably impressed the locals at the time for the same reason the Eiffel Tower was impressive. When I saw the plans at the California State Railroad Museum a few weeks back, I found they're just as interesting underneath, with a three foot tall I-beam running down the center of the car, and all sorts of cross-bracing supporting the interior A-frame for the slope sheets.

The cars are also interesting appearance-wise because they look unlike any other freight car. The available photos make the cars look big and boxy, even though they're only 30 feet long - short by modern standards, and even small for my 1930's era. The unusual hinged doors covered each side completely, and the arrangements of hinges catches the eye. Their air-operated mechanism for the side doors are beautifully steampunk with ten foot long operating levers covering the sides.

And finally, the cars were present at the Southern Pacific's greatest battles. The cars were intended to dump fill on each side of a railroad track. Three hundred were bought for the Lucin Cutoff work - Southern Pacific's attempts to tame Utah by running a railroad straight across the Great Salt Lake. They were used in the fill work to block the Colorado River's escaping of its old channel as it tried to fill the Salton Sea. The cars hauled debris away from San Francisco after the Great Earthquake and Fire of 1906. They were used in countless other improvement projects, with some cars lasting into the 1950's in maintenance-of-way service.

These cars were printed on my Form One printer, printed upside down (top to bottom) for easier support during printing. The needed support structure attached along the top rim of the car, and also had individual supports down into the interior. These versions of the model have only been painted with primer and touched up with a bit of putty; I still need to install grab irons, brake gear, and still need to paint and decal the models.

The air-operated mechanism for opening the doors was the touchiest part of the cars to design, and I'm surprised it printed as well as it did. You can see that some of the levers are supported from behind so that the car can be printed in a single piece. I found the lower frame the hardest where shallow angles support the slope sheets that stick out just beyond the edges of the car. The interiors were the fun part because they forced me to fully understand how the car was supported - posts come up from the lower frame to support the top of the car, and a different set of supports braces the door below the hinge point.

Oh, and a pro tip for folks building 3d-printed model railroad models: always take a picture with a coin or X-acto knife. Otherwise, you'll look at your photos and think "wow, that's a lousy model", and then you realize the detail you're complaining about is a literal pinhole.


  1. Robert, you continue to impress with both your research and technical prowess. Looking forward to seeing these in person some day.


  2. Hi, Bill!
    I'll be in Portland, so I'll bring them up to show.

  3. And a few of these cars received SPMW numbers. For that reason, I would certainly like to purchase one if it should become available

  4. Robert; Might the file be available to make an "S" scale model? TCC:}

    1. You've got to be quite an SP freight car fan to want a Battleship! I have no plans to distribute the 3d model; I'd like to make and sell these some day. If you're really interested, I can try putting one on Shapeways, but we'd need to figure out mounting holes and height for scale couplers and trucks. Making one of these from Shapeways FUD would be somewhere north of $125.

  5. Love the Battleships!!!!
    They are very close in design to two large batches of ore cars of the EP&SW and built by Pressed steel Car Co. around 1903-06. The EP&SW is murder to research and just about non-existent on line. The major differences I see right off are the side doors on the EP&SW cars had alternating "sawtooth "like external bracing and the doors were operated by four air cylinders...but mounted underneath and I've yet to see a photo showing anything external.
    Is there any way I can get a copy of the plans from you? Name your price!

  6. I got the plans from the California State Railroad Museum; they should be able to send you a TIF of the scanned plans for about $10 each. Plans I used listed below. CSC 2768's the most interesting and largest plan; the others were all 8.5 x 11 drawings.

    If you're near Sacramento when there's not a pandemic on, definitely go visit, view the plans in person, and order scans of the ones you like. I'd pay for a digital copy of the big print no matter what and make a paper print at a copy store - it's interesting, and it's handy for any model you'd build. For the smaller plans, I'd recommend making a cell phone photo at the CSRM Library if you're there. Note these plans were all off site, so you'd need to request them in advance to see them in person.
    * CSC 2768 ("Side, End, and Center Construction of 100,000 lb Self-cleaning Side Dump Car", dated April 23, 1902) - side views, rivet patterns, and internal truss assemblies
    CSC 2766 ("Arrangement of the Air Dumping Device for 100,000 Self Cleaning Side Dump Car): Detail of pneumatic cylinder for unlatching doors. The side plan CSC 2768 doesn't detail this mechanism, so this is good if you're trying to understand the mechanism.
    CSC 2767: Piping for 100,000 lb self-cleaning side dump car. Brake piping only.
    CSC 2764: Arrangement of brakes for 100,000 lb self-cleaning side dump car, april 23 1902. Shows brake rigging detail.
    PSC 3522 Plans of hardware and machined parts for side dump hinges and latches.

  7. Are there any published photos of the EP&SW cars? I'd be curious to see how different they look.

    You may already know about the SP files at the University of Texas El Paso library; they've got a bunch of files, including some boxes from the division engineer for maintenance of way. I found some great materials about the Hart gondolas there. You might look through the finding aid to see if there's any references to the side dump cars.