Compared with the drill and blast method, TBM tunnelling has significant advantages with high construction efficiency, low project cost, conducive to environmental protection, favorable stability contr.
[pdf] Since 2003, HardRock Infrastructure Services has been taking on the kinds of projects others will not touch. What started with one man, one rig, and a pocketful of credit cards quickly evolved into one of the top providers of horizontal directional drilling (HDD) services in the United States.
[pdf] A Pile Top RCD fitted with a 2-metre diameter drill bit is estimated to be capable of “mining” about 7 tonnes of Ore per hour. The Pile Top RCD is capable of drilling holes with inclinations from 90 o (vertical) to 72 o. The working deck has variable geometry to keep it level.
[pdf] 
