BRM Cake Box Challenge - Klosterstollen



Builder: Helmut Schmidt

This is a 1-22.5 scale model of a visiting tour to the “Klosterstollen”, a former coal mine located in Barsinghausen, Germany. Prototype rail gauge is 600 mm so the model’s gauge is 26.7 mm.

It is going to be part of my “Klosterstollen” model, which shows the adit opening and infrastructure for the visitors’ mining trains above ground. For more information visit

I’m planning some additional underground insights and so the cakebox model is a first test for prototypical modeling of an underground situation. At this scale it’s easy to add some functions and illumination. I’ve been a volunteer visitors’ guide for some years at the mine and this is why there’s a 3D printed figure of me talking to the viewers via sound module. There are keys to choose from three languages. A Dinamo OC32 controls this, including a servo drive to move the mining car by a model of an compressed air winch made from brass.


All items were self-built and there were no additional costs aside of some materials and tool wear. Main components are MDF, sand, coal and colours.

There’s an extensive description with pictures and a video on RMweb.