The former Constantin colliery !

 

Protego cap at the former Constantin colliery !


In this picture you can see a so called Protego cap. Even in very old shafts and roadways abandoned a long time ago, a high concentration of methane gas coming from former mining areas can develop. If the concentration is too high, the gas could theoretically get into the air at the surface and cause an explosion. To avoid this the Protego caps have been constructed. They make it possible that the gas can get out of the old shafts etc. in a controlled way and because of that the problems I mentionned before do not exist.

The cap that is visible in this photo is located on the area of the former Constantin colliery between the cities of Bochum and Herne (Germany).

A received this photo from the owners of the website called Foto-Ruhrgebiet.