Presented during CONEXPO-CON/AGG 2017 in Las Vegas, the new MC 28 A HD (where A stays for “anchors” and “HD” for “heavy duty”) is a 29-tonne class drilling rig specifically designed for anchor drilling. Based on the design of the MC 28, this rig features an innovative rod and casing carousel, which allows the handling of both single rods for open-hole drilling and the combination of rods and casings for overburden drilling. The use of the carousel reduces the risks related to the manual handling of the equipment, improving safety levels and resulting in increased productivity and reduced labor costs, as the entire work cycle can be performed by one person instead of two or three.
The carousel can handle up to 7 pairs of rods and casings with variable diameters (up to a maximum of 114 mm for rods and 178 mm for casings), up to 3.5 m long, reaching a maximum drill string length of 30 m. No adjustment of the gripper system is required when changing from one diameter to the other. When the drilling and grouting are completed, the carousel remains fully loaded and ready for the next borehole, without requiring manual handling of the drilling tools. The MC 28 A HD can reach 9500 mm feed stroke, thus allowing for the use of longer drilling equipment. The design of the machine incorporates enhanced mast kinematics allowing the MC 28 A HD to reach the lowest drilling positions required for the installation of anchors and permitting safe work even in confined spaces.
The heavy-duty design comprises a reinforced variable width (2500 – 3400 mm) undercarriage providing additional stability. The machine on display in Las Vegas was equipped with a 205 kW Caterpillar C7.1 engine complying with the latest EU Stage IV / US EPA Tier 4 Final emission standards, allowing to run simultaneously a 202 l/min flushing pump and a double head system providing up to 2400 daNm torque on the lower rotary head and 1050 daNm torque on the upper rotary. Thanks to the powerful engine, the MC 28 A HD can be customized according to the client’s needs using the wide range of accessories available.
The rig is completely radio controlled thanks to the innovative radio control system designed by Comacchio. This system allows a single operator not only to manage the tramming, drilling and machine set-up from his control panel, but also to operate the hydraulic rod and casing carousel.