Model Railroading > Some R&D Work While Social Distancing

Well, one potentially good thing about staying home the last few months has been renewed attention to projects that have been back burnered for a while.

Here we have a piece of anthracite coal, which I recently found at an old derailment site.  I've been looking for nice big pieces of anthracite to sculpt on, and these have been ideal.  I'm playing around with it to make a model of an active bench in an open pit mine or quarry.  In the front, you can see the "worm holes" from the last round of blasting, while up on top, you can see the cones of cuttings from the shot holes that will be loaded with the next round.  Picture a small drill rig perched over one of those holes.

I first thought of trying this about 20 years ago, but hadn't found the combination of starting material, tools, and time.  Turns out it was simple, once I gave up on the idea of actually using one line of drilled holes to break the rock.  Realistic sized, small diameter drill holes simply aren't large enough for the job.  Not without filling them with real dynamite, anyway.  So the "worm holes" here are actually shallow saw cuts along a natural break surface, made with a thin profile hacksaw blade.  The holes up on top are real holes, drilled with a conventional power drill.  The cones of debris were generated during drilling, and stabilized with low viscosity super glue.  You could not do this drilling on virtually any other kind of rock without seriously high powered tools. 

Next project is to see if I can transfer this pattern to flexible latex, maybe make a product out of it.

Gardiner Cross
Cripplebush Valley Models



Edited 1 time(s). Last edit at 06/03/20 18:34 by march_hare.

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That's real neat.

That looks really good. I worked in surface coal mines all over the country for several years many years ago. Some mines shot the coal to break it up as you are modeling and some used Cat dozers with a ripper to rip it. Ripping was more common in the midwestern mines with bituminous coal. Anthracite mines almost always shot it because that coal is so hard. One thing I can suggest is that when they shot the coal there was more than one row of boreholes per shot. They would typically drill, shoot, and load out between 100' and 100 yards at a time so there would be maybe twenty rows of holes with about 4 holes in each row. On a small representation of that on a model probably 4X4 would be enough to look realistic.