Carbon Black Hoppers

A few years ago I posted a blog covering Thrall 5750cf carbon black hoppers. At the time I had completed CAD drawings of all the variations on the Granuflator-equipped Thrall car from 1968 to the 1979 version that was built into the 90s. I designed the CAD files so that the car could be 3D printed as a flat kit with details added by the modeler. No doubt it would have been an expensive kit to print, not to mention expensive to procure all the detail parts, then assemble the model and apply paint and decals.

So I was relieved when Scale Trains announced they'd be producing the 5750cf carbon black car in the 1977 version and the 1979 version. I was hopeful they'd tool up body variations to offer some of the earlier cars, but that didn't happen. Since these are by far the most common carbon black hopper I was used to seeing I ordered six. I figured I probably spent as much on those six as I would have on two of my 3D printed kits.

Scale Trains also announced a Thrall 4727cf carbon black hopper at the same time. Unfortunately for me, this car represented a mid 90s prototype. But I wondered if it might be possible to backdate this model to the 1974 version. Of all the carbon black hoppers Thrall built in the 70s and 80s, this one actually looked like a covered hopper instead of a boxcar.

With six of the boxcar-like covered hoppers in my hands I had the makings of a substantial fleet for the carbon black producers and customers off either end of my dream layout. I have to hand it to Scale Trains, these cars are exquisite. I don't think I could have done as nice a job with my 3D printed kits no matter how much I was willing to spend.

But the uniformity of these six cars got me thinking about some of the ACF built carbon black cars the late Wade Griffis had built. He offered decals through his Black Swamp Shops and had a kitbashed or scratchbuilt models to show off each of the decal sets he designed. He was really a pioneer and his models were quite good. I'd looked over these models a dozen times or more and figured I'd build one of each someday.

Back in April someday finally arrived. I figured while I was at it I'd take a crack at a modernized version of the old Rail Shop ACF 3000cf carbon black hopper. And for good measure I bought one of the Scale Trains Thrall 4727 hoppers to backdate. So if six was a good sized fleet, four more new carbon black cars would be even better.

First up was the Rail Shop car. This model began as an ACF 3000cf carbon black hopper. The prototypes were built between 1933 and 1949. In the 1960s many of the cars were enlarged to 4000cf by raising the roof 28 inches. The modification also included replacing the staff handbrake with a horizontal brake mechanism, partial removal of the A end side ladder and replacement of the wooden running boards.

The kit was built per the instructions with a few exceptions. To replicate the taller prototype, the sides were cut along the base of the riveted zee at the top of the side stakes. New side extensions were built from styrene sheet and strip. Likewise the ends were cut and extensions were added. Brake gear components were replaced with Moloco parts, other than the brake cylinder/lever part, which is from the kit. The trucks were replaced with some from a Proto2000 gondola kit. A placard was added to each side to display the Columbian Carbon logo. A Plano running board was installed along with a platform below the handbrake. I lettered the model with Wade's Black Swamp Shops decals. I ended up replacing the kit's outlet gates with some 3D printed gates and covers I made, but these aren't shown in the photos.

Next up was the Scale Trains 4727cf hopper. I removed the side stakes using a Dremel tool, a chisel, then finer and finer grit sanding sticks. The roof and hatches were replaced with a 3D printed part adapted from my original Thrall 5750cf CAD file redesigned to fit the Scale Trains model and reuse the etched running board. I built up new side stakes from tee and strip styrene to create the columns used by Thrall in the early 70s. Once again I used some of Wade's decals, though the decals were intended for a model of a 5750cf car.

Continuing the trend of ramping up the difficulty of the build, I took on an early ACF 4589cf car. The prototype is a Plate C car, so I started with a 1970 and earlier Atlas ACF 4650cf hopper. The length is pretty close with the Atlas car being just a little too long, but not long enough to jump out. The slope sheets on the 4589 are closer to the rail making the vertical portions of the car ends taller. I chose to live with the difference on this model but in the future I may start with a car that's a better match for the ends. One unique feature of the early high-handbrake 4589 is the area behind the tall side ladder. It's recessed to allow some space behind the ladder rungs. The holes on the roof were plugged and new 3D printed hatches were installed. This car received new Kato 70-ton trucks. Black paint and Black Swamp Shops decals set no. 104 were applied.

Finally, I kitbashed an ACF 3390cf carbon black hopper from the Atlas 3-bay cylindrical hopper. Again the first step was to plug the roof holes and blend the plugs into the roof contour. Next I filled in the seams in the body and primed it. The entire car was shortened by four scale feet with a single section taken from the middle of the body and two two-foot sections taken from the underframe between the bays in order to obtain 12-foot hopper outlet spacing. I added new 3D printed hopper outlets, modified the end cages and installed the Plano running board set. The trucks were replaced with Exactrail 70-ton trucks and the roof hatches with some parts from an Athearn ACF 5250cf covered hopper I had originally intended to use for this model. Again, Black Swamp Shops decals were used.