For many, coal mining still evokes images of backbreaking toil: of miners hewing rock with jackhammers and loading coal on carriages. Yet the reality is far removed from this outdated picture. Over the past few decades methods of coal extraction have changed enormously.
Under NWR’s ownership, OKD has undergone a dynamic transformation. It is now a modern company with state-of-the-art technology. This has in turn led to improved safety and higher productivity, as well as easing the physical burden of working underground.
“Those wishing to observe a miner hewing black coal from a seam with a jackhammer in his hand would have to travel back in time to the 1960s. What’s more, this method was primarily applied in mining seams of small thickness and downward slope, but even there ploughs and scrapers began to be gradually used. When it comes to the higher Karviná coal seams, mining was mechanised, with cutter loaders and supports in use,” explains Jiří Plac, adviser to OKD’s production manager. At the time, conveyor belts transporting coal into storage bins were already installed in the mines. “If coal was not conveyed on a belt up to the storage bins beneath the skip frame, it was poured into carriages under the coal face and then transported further to the hoisting shaft and from there to the surface for further treatment,” said Plac.
POP 2010: The turning point
The dynamic changes that have occurred over the past few years do not, however, soley pertain to coal extraction. Innovation has impacted a wide range of operations. Modernisation has been taking place continuously for several decades, yet in the case of the Ostrava-Karviná mining district the year 2008, when POP 2010 (Productivity Optimisation Programme) was launched, was the turning point.
Average daily coal extraction per coal face per day rose from 1,421 tonnes in 2000 to 1,743 tonnes by 2010, and to as much as 2,800 tonnes in coal faces equipped with the most advanced technologies. “Diametrical differences are also evident when it comes to work safety and, above all, in the linking of the entire mining system. What can now be achieved with the new boring machines and mining sets would not have been possible with their predecessors, although I don’t want to denigrate their qualities since they were excellent for use in certain conditions,” said Plac.
Transport modernisation
Retired miners who visited coal faces in OKD mines were of the opinion that: “The coal remains the same yet the technologies seem to be from another planet.” When it comes to the conveyance of material, for instance, there have been changes leading to efficiency. Some time ago containerisation was introduced, whereby only material needed at a certain time is transported to its respective place. This has resulted in the optimum use of resources.
Modernisation has reduced the physical labour and increased travel comfort to the coalface. In most cases, workers do not have to walk far to the workplace; they are carried by train. This saves time for miners from peripheral parts of the allotment and for those working at coalfaces beneath the pit bank where the lift ends. Previously, they had to get there on foot or cableways. In addition to greater safety and comfort, this system is quicker.
New technologies
The mechanisation of work and the introduction of state-of-the-art technology has brought with it requirements for heightening the profiles of galleries. Former employees marvel at the larger gallery space. Where miners once had to crouch it is now possible to walk. “It is necessary to handle the equipment. This also brings other positive effects, such as better ventilation system and improved working conditions. Supports with a higher load-bearing capacity are used nowadays, hence the profiles can be higher,” explained Plac.
New technologies and the attendant higher gallery profiles have a direct impact on extraction. In the past high seams had to be divided into two parts and coal was mined on so-called bridges – the upper part was extracted and after a certain time the miners returned to the coal face to extract the lower half. The new mining sets are able to extract thick seams at once. This has a positive impact on production volumes.
More comfortable working environment
Another surprise for retired employees is the tidiness of the workplace and improved lighting of coalfaces – two changes stemming from the great emphasis NWR places on safety. In addition to the added comfort, miners at a well-lit coalface have a much better overview of the workplace than when they were entirely dependent on personal lamps. In the past, a lack of order in the workplace often caused unnecessary accidents.
Personal protection aids serving to increase work safety have been significantly improved in quality terms, too, and have been welcomed by miners.
Bolts: more efficient use of workings
New technologies have also resulted in changes to work in front of and behind the coalface. Whereas a gallery would previously be bored and then buried after the coal face was worked out, and a new gallery had to be bored just a few metres from it, thanks to the bolting system workings can now be used twice. “It isn’t necessary to apply other capacities when boring, thus the employees can be used efficiently elsewhere. Physical demands have decreased, labour efficiency has increased and there is time for the preparation of work,” said Plac.
Over the past few decades the nature of work in black-coal mines has changed radically. Yet in some respects it has stayed the same. “Mining has always been and will continue to be an activity where people encounter nature and its laws every day, and these laws must be respected. The miner has to be responsible for his own safety and that of his colleagues and friends, too. Belonging to a mining team makes our work, however demanding and occasionally cruel, a thing of beauty,” concludes Plac.
Marek Síbrt,
marek.sibrt@okd.cz