Akkerman's New GBM allows up to 42-inch rock installations.
Up to 42-inch rock utility installations are now a reality for Guided Boring Machine (GBM) contractors, with the release of Akkerman's exclusive Rock Boring Unit (RBU). Using the 24-, 30-, 36- and 42-inch diameter RBU, contractors can use existing equipment for a steel casing installation with pilot tubes in up to 18,000 psi UCS ground conditions, or an unguided installation in up to 25,000 psi UCS geology.
The RBU consists of a casing assembly specific to the project pipe diameter; bearing assembly with a 4-inch hex connection; and a high-thrust, load-bearing cutter head with disc cutters capable of up to 90,000-foot-pound thrust loads. By fracturing and excavating rock with aggressive 6.7-inch disc cutters, the RBU increases the diameter of the bore. The cuttings enter the RBU face, and travel through casings and augers for removal.
Rock boring can be achieved multiple ways using Akkerman GBM equipment or any conventional auger boring machine system. When guided, the RBU follows the pilot tube string, led by a Rock Drill Adapter (RDA), rock appropriate TriHawk drill bit, and lubrication regime to displace cuttings. The RBU follows the pilot tube adapter and connects to the lead casing and auger hex.
Following the pilot tube pass, direct steel casing installations with an RBU can be powered by a GBM 4800 Series system with a high-torque casing adapter for added torque, or an augering adapter assembly for rock discharge. Guided auger boring contractors use the GBM 240A system for RDA pilot tube installation with any conventional auger boring machine system to power the RBU steel casing pass.
For unguided applications without a. pilot tube installation, the RBU pilot tube hex connection void is filled with a full-face disc cutter insert, and the RBU is launched by the auger boring machine. (800) 533-0386, akkerman.com