The Building of the Compressed Air Locomotive

I had planned all along to include a mining theme in the layout expansion that I started on in 2020 and completed in 2022. I was contemplating having a small locomotive running in and out of the mine. Then I began to question whether they really used steam locomotives in old mines. The answer is "no", and it makes perfect sense that you do not want a fire breathing monster inside mines, especially a coal mine. So what did they use? Compressed air locomotives like the one pictured here. I decided to see if I could build such a model.

I started with a small porter since its motor block and wheels were exactly the right proportions for a compressed air model. I would do some extreme kit bashing.

About the only thing I would save is the motor block and wheels.

I cut most of the cab platform off the back end.

Then I began the process of extending the frame. And, oops, putting back at least a little of the cab platform.

I used Fusion 360 to design some tank parts and 3D printed them with my resin printer.

I also used Fusion 360 to design some miscellaneous detail parts that I could 3D print.

Incorporating all of the actual linkage and detail from the real thing would end up being not just difficult, but quite fragile. I added just enough to be representative of the prototype.

I'm reasonably happy with the end result.

I stole wheels off some O-gauge cars to come up with wheels small enough to be typical of ore cars that would be seen with a compressed air loco. I 3D printed frames for the ore cars. The original plan was that the mine tunnel track was a straight shot, so the fixed couplers on the cars need to get replaced before this little train becomes functional. The fixed couplers don't make it around the curve. But once I fix that, the motor block in the compressed air loco is functional, and the track it sits on is wired for track power. There are also sensors in the track to tell the controller where the locomotive is. Once controller programming is complete, this little ore hauler will automatically go back and forth between the mine and the loading tower. Or at least that's the plan.