The Robbins Main Beam TBM for the Lower Meramec Phase 2 tunnel packs a lot into a small 3.35 m diameter: 360-degree probe drilling, high-performance drive motors, 192 tons of machine.  See the machine in action in this one-minute video of its factory acceptance test in Solon, Ohio, USA.   

The robust Main Beam is currently boring its 10.1 km long tunnel in shale and limestone for contractor SAK Construction. Located in St. Louis, Missouri, USA, the completed tunnel will convey sanitary flow from the Fenton Wastewater Treatment Facility to the Lower Meramec Wastewater Treatment facility at the junction of the Mississippi and Meramec Rivers. Click here for information about Robbins in the tunnelbuilder archive and visit https://www.robbinstbm.com/. 19/23.