Repair And Maintenance Services At Jsw S.A. Plants Including: Modernization Of The Shaft Chair, Modernization Of Hydraulic, Electrical And Mechanical Systems Of Łzks-500 Along With Accompanying Installations Based On Doc. Renovation, Renovation And Verification Of Individual And Portable Methane Meters, Major Overhaul Of Longwall Shearers, Renovation Of Braking Bogies Of Suspended Monorails