Patna Metro Advances: Third Tunnel Boring Machine Lowered into Launching Shaft

Patna, 19th October 2023: In a major advancement for the Patna Metro Rail Project, the first tunnel boring machine (TBM) has been lowered into the launching shaft for the underground metro route between Gandhi Maidan and Akashvani stations. This marks the deployment of the third TBM in a series, aimed at expediting the construction of the vital tunnel segment.

Key Highlights

The TBM assembly, weighing approximately 450 metric tons, was lowered 52 feet below ground level. The operation utilized four strand jacks, each with a 300 MT capacity, and a megalift with an overall capacity of 1200 MT. The descent into the launching shaft typically takes between 5 to 8 hours.

Operational Details

The TBM, labeled TBM 3, was positioned into a 32-meter long and 25-meter wide launching shaft at Gandhi Maidan underground metro station. From here, it will cover a distance of roughly 966 meters to reach the Akashvani Metro Station. To offer perspective on the weight of the TBM, it is equivalent to 28 50-seater buses, each weighing approximately 16-17 metric tons.

Ongoing Work

Notably, two other TBMs are already at work at the Moin Ul Haq underground metro station. These machines, TBM 1 and TBM 2, are set to travel a distance of about 1.49 kilometers to Patna University, where they will be retrieved and redeployed for further construction.

What is a Launching Shaft?

For those unfamiliar with metro construction, a launching shaft is a specialized structure composed of concrete and steel. It serves as the starting point for the Tunnel Boring Machine (TBM) and facilitates its subterranean journey.

By integrating advanced machinery and innovative techniques, the Patna Metro Rail Project is on a fast track to redefine urban mobility in the region.