Underground transportation in Borynia is carried out using diesel and electric-powered machines. Electric machines enable more comfortable and safer work.
“Due to absence of a locomotive depot at the 950m level, so far we have used diesel machines. The temperatures in the area would exceed 28 degrees, so we organized work in four shifts. The implementation of the Electra battery-powered locomotive has made it possible to reduce the temperature at the driver's workstation. Now we can work in a three-shift system,” says Dariusz Piżyk, manager of underground transport mining works at the Borynia Section.
The battery-powered locomotive makes it possible to transport people, cargo and equipment. Charging its batteries is possible in a coal dust and methane explosion zone. This not only eliminates the need to maintain an additional pit with a battery charging station, or fuel management station in the case of diesel locomotives, but also significantly reduces maintenance costs.
“We refuel diesel machines at stations, hydrogen-acid batteries are charged in special chambers, and in the case of new-generation batteries the charging is done by connecting a single machine via a cable to the mine's contactor switches,” says Szymon Szewczyk, a driver at the Underground Transport Division. “Charging is faster and more convenient. The charging is virtually the same as charging an electric car,” he adds.
The operation of diesel machinery requires daily maintenance, and there is also an additional cost. In the case of electric machines, maintenance is much less frequent and less expensive. The Electra locomotive is equipped with a maintenance-free battery and a system that allows energy recovery during kinetic braking. The new model of the machine has two gears and cruise control. In the higher gear, the maximum speed of the locomotive is 5 m/s, while in the lower gear a slow start is possible. An interesting feature is cruise control, which at first was described as an unnecessary invention. It turns out that driving in this mode is used by drivers on a regular basis, as it is very precise. A fixed speed, adjustable in 0.1 m/s increments, allows for more controlled linking of the machine to units.
Electric locomotives with the ability to recharge in the drift are likely to displace machines with traditional solutions in the near future.
“We have already purchased two dry-acid batteries for use in Lea BM12 locomotives. The first economic analyses are positive. If our expectations prove true, we will abandon hydrogen-acid batteries in favor of dry-acid batteries, which are also suitable for charging in the mine workings. Then we will be able to eliminate the battery charging station at the 838m level, which will significantly reduce fixed costs,” Dariusz Piżyk concludes.
