Main Beam TBM Launches for Hawaii’s Longest Tunnel
The Machine, Nicknamed “Rock Girl,” Will Improve Wastewater Infrastructure
In the spring of 2015 by the shores of Oahu, Hawaii, a Robbins 3.96-meter diameter Main Beam TBM began its long journey.
The tunnel boring machine (TBM) started its excavation on a 4.6-kilometer drive for a new sewer tunnel in Honolulu, Hawaii. The machine, nicknamed Pohakulani, meaning “Rock Girl” in Hawaiian, launched from a 23-meter-deep starter tunnel on a mission to bore through almost 4.8 kilometers of basalt bedrock. Contractor Southland/Mole JV is building the Kaneohe-Kailua Wastewater Conveyance Tunnel for the city and council of Honolulu, which will improve wastewater infrastructure by eliminating overflows during rain events.