Komatsu, Codelco trial electric Mining Tunnel Boring Machine

Komatsu’s Tunnel Boring Machine (TBM) for underground hard rock mining. (Photo: Komatsu Ltd.)

Through its subsidiary Komatsu Cummins Chile Ltda. (KCC), Komatsu Ltd. will collaborate with Codelco, a major state-owned mining company in Chile, to trial a new tunnel excavation method using Komatsu’s electric-powered Mining Tunnel Boring Machine (TBM). The trial will start in 2024 at Codelco’s Chuquicamata Mine in Chile.

According to Komatsu, use of a TBM has generally been limited to excavating nearly straight tunnels. The Mining TBM is equipped with technologies designed to enable adaptability to small curves, reversing and passing intersections in hard rock tunnel excavation, which the company says improves the flexibility of the equipment and enables excavation of tunnels according to the unique designs of the mine.

The Mining TBM works by continuously performing a series of processes, such as excavating rock with disc cutters, and discharging the chipped rock backwards with belt conveyors, Komatsu explained, all while fortifying the excavated tunnel wall. Excavation with disc cutters improves tunnel strength and stability by creating a circular tunnel shape with smooth walls that are less damaged when compared to the drilling and blasting method, the company added.

In addition to being powered by electricity, the newly developed machine does not require the use of blasting and performs a series of tunnel excavation processes with a single machine, reducing the equipment required.

“The result is a new excavation option that reduces the creation of greenhouse gases and particulate matter emissions for an improved underground environment that requires less ventilation than other methods,” Komatsu stated in announcing the collaboration. “At the same time, it significantly increases the productivity of personnel associated with tunnel excavation work compared to conventional methods.”