tunnel boring machine / mixshield TBM

The XRE TBM—standing for a Crossover (X) between Rock (R) and EPB (E), has been designed and deployed by Robbins on multiple projects that feature sections of both hard rock and soft ground in the tunnel alignment. Using features of both EPB and Single Shield Hard Rock machines, the XRE has successfully been used on mixed ground projects in Australia, Turkey, Mexico, India, and more. Download a specification sheet here.

Ideal in Unstable Ground

The XRE’s unique design features make it a strong choice for mixed face rock and non-self-supporting ground. A single direction cutterhead cuts down on tool and machine wear and eliminates the problem of regrind, which causes undue wear on machine elements. Two-speed gearboxes efficiently use power to generate high torque at low RPM, allowing the XRE to get through squeezing geology and fracture zones that might leave other machines stuck.