During the summer of 2011 EDILMAC realized in Umbria region (central Italy) the ventilation shaft for a tunnel placed in a complex of dams and water ducts for agricultural use.
The vertical shaft, 280m long and 2,44m wide, is excavated in well cemented quarz sandstone with diffuse marly lenses. For the fact the shaft has a considerable length and a deviation from the vertical wasn’t allowed the use of directional tools for the pilot hole drilling was required; those tools usually work with high pressure water pumped into the drill string but due to the rock condition with widespread karst this was impossible even to think. Thanks to Micon Gmbh world leader in directional drilling tools which is a partner company in several jobsites we tested in world premiere the new Air-driven RVDS (Rotary Vertical Drilling System) achieving some good results that can make us hope for an upcoming new generation of tools in the directional drilling market.
For the job execution we used a new refurbished and upgraded Robbins 73RVF C developed with Atlas Copco we built at the beginning of 2011 from an old Robbins 73 on which all the mechanical parts of motor, gearshift and transmission were totally changed, the hydraulic and electric panels were built from anew and several other technical and functional improvements were made. Thanks to the newest technologies available and to the technical choices made during the upgrade of the machine this is now powerful almost as much as a Robbins 83 keeping the dimension and weights of a Robbins 73.
Technology combined with experience made once again the difference and proved the strengths of a company that is constantly evolving.