The colliery's safety precautions !

The safety lamp !

In this picture you can see a modern safety lamp as it is common today. The accumulator consists of three divided cells. This lamp provides the miner with nearly 24 hours of light if it was recently reloaded. The lamp (in the picture it is fixed at the helmet) has two different candlepowers and is - when used in hard coal mining - protected against causing firedamp explosions. That means that when turning the lamp on and off no electric sparks can effect the air outside the lamp so that the methane gas, that can be present, cannot explode.

The CO-filter !

The second very important thing a miner has hanging on his belt is the CO-filter. If there is a fire underground, this causes that the oxygen brought here for the miners will be used up very fast and will be transformed to toxic carbon monoxide, only one breath of which can be lethal for a human. For this case the filter has been made: It contains a filter of activated carbon that is able to transform this toxic gas to air that can be breathed by a human for a period of time that is long enough to reach an area underground to where fresh air comes from the surface. By clicking on the picture, you can see the large version of it and get more detailed explanations !

The water barriers !

All over the colliery's roadways there are white plastic tubs fixed under the ceiling. These tubs are filled up with water and they are mounted for the case that - even if everything in done against that - a firedamp explosion occurs. Before the flames of the explosion rush along the tunnels there is a wave of air pressure, comparable to a very strong storm. This wave will destroy the plastic tubs and by that create a fog of crowds of small water drops in the tunnels. If the flames come along after the air pressure they will be exstinguished by the fog.

The methane sensors !

In all parts of a colliery's tunnels methane sensors are mounted, controlling the concentration of that gas around the clock. If it is too high in a certain area, all machines and other electrical institutions are turned off immediately until the gas concentration reduced to an acceptable value.

The shield supports !

In the following pictures of the langwall mining area you will see the heavy machines working there and the huge shield supports avoiding that the roof falls down and endangers the miners. The shield supports are 3 metres (approx. 10 feet) wide and weigh several tons. In a common longwall mining area of about 350 metres (approx. 1.166 feet) there are 120 to 130 of these shields.

These shield supports are driven by oil pressure and they are able to push against the roof with the mutiple of their own weight. In order to move forwards the shield supports are lowered, then they advance towards the face again hydraulically and finally they will be reset again. If the shield supports are fixed between floor and ceiling again, they are able to push the whole area of the face chain and the production machines towards the coal seam so that these machines are close enough for the next pass through of the shearer, for example.

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