We own 2 diesel hydraulic Atlas Copco tunnel-rigs. This entails significant savings in rigging costs and -time since the mine extends over such a large area and the drilling sites are located far apart. First a 4 x 7 meter pilot tunnel is drilled. Thereafter the remaining limestone width is stoped. The average tunnel size becomes some 7 meter in height and 15 meter in width.
For blasting purposes we own a specially constructed rig with a lift and air-compressors to blow the powder explosive (anfo) into the drilled holes. Ignition takes place by means of nonel-bade millisecond percussion caps.
After the blast, loose rock is removed by means of a hydraulic hammer and after this has been done no loose stones remain so that it is not necessary to bolt the remaining surface.
Loading is carried out by means of 20 mt GHH mine loaders and the stones are conveyed to the silo by means of Volvo-dump trucks. With transport distances approaching 3 km one way, it is necessary to maintain an adequate road standard. For this purpose we operate a 5 mt Gehl-scraper, witch uses rubble from the mine as road building material.