|
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.
|
