The wall is excavated in the area exposed to the highest risk of methane explosion, i.e. methane threat category 4, which is also under threat of gas breakouts and rock outbursts. Under these circumstances, excavation works can only be conducted with adherence to the strictest safety requirements, which can only be guaranteed once the mining process is fully automated.
“The solutions which we have applied in the area of this wall are exemplary. It complies with all safety requirements, and at the same time, allows us to achieve good production results. We prove it right that safety does not rule out effectiveness,” stresses Andrzej Tor, Vice-President of the Management Board for Production.
Wall C 1 is excavated in deposit 404/1, which is about 1.45 metres thick, at the depth of 1,000 metres. The average output from the wall amounts to 3,200 tonnes of coal per day (the highest was 3,500 tonnes), and thus is almost twice as large as the output produced so far from other walls of similar characteristics. This has been made possible by equipping the wall with a number of state-of-the-art solutions which facilitate coal extraction in automatic mode. These solutions are based on technologies of the following companies which form part of the KOPEX Group: Zabrzańskie Zakłady Mechaniczne S.A., Fabryka Maszyn i Urządzeń TAGOR S.A., Rybnicka Fabryka Maszyn RYFAMA S.A., and Kopex Electric Systems S.A.
What is particularly unique is the so-called double-track communication, which makes it possible to record everything that happens in the wall, and ensures that machines and equipment react properly. The longwall system operates in two modes. The choice of a mode depends on mining and geological conditions of the wall, and the technology applied at a given time.
“The operation of a coal-cutting machine is supervised by its operators, who can take control over the machine whenever the need arises. The operators can move the coal-cutting machine across a certain section of the wall without adjusting a standard cutting, or change the parameters of the standard cutting in a way that takes into account the required corrections. In order to ensure that the crew is safe while the longwall system is in automatic mode, powered lining sections give a sound and visual signal indicating that the work cycle has started. What is more, a person working in the wall has a possibility to block the operation of some or all sections", says Andrzej Meder, Director of Technology and Development at KOPEX SA.
Due to threats resulting from excavating the wall in the area which is exposed to the risk of gas breakouts and rock outbursts, a high risk zone has been created, in which only a limited number of people can work. The ARGUS system for monitoring the movement of the crew has been installed to inspect the number of workers employed in the area of the wall. Entrances to the zone have been equipped with gates and boards which show the number of workers working in the zone at a given time.
Supervision over the number of workers in the zone is exercised by a mine operation controller. The information concerning the number of workers is also displayed on the main synoptic switchboard on the screen of the central visualisation computer located in the cab of the system operator in the bottom gallery.
“Since the very beginning, wall brigades have demonstrated an enthusiastic and open attitude towards the technical solutions applied. At the moment, the system operates in full automatic mode, and the workers who operate the equipment in the wall are very professional,” says Sławomir Polak, team foreman of extraction brigade G-2.