Slow Dig Derails Metro's May Target, Second TBM Yet To Start

Bhopal (Madhya Pradesh): Construction of Bhopal Metro's first underground corridor has fallen significantly behind schedule, raising fresh concerns over the pace of work being carried out by Madhya Pradesh Metro Rail Corporation Limited (MPMRCL).

The 400-metre underground stretch between Bhopal Railway Station and Pul Patra, targeted for completion by May 31, remains far from finished with Tunnel Boring Machine (TBM) having advanced only about 50 metres so far.

Excavation for the twin underground tunnels began on March 30, nearly 75 feet below ground level near Bhopal Railway Station. The underground section between Pul Patra and Sindhi Colony will be 3.39 km long.

At the time of the launch, Metro officials had projected that the initial tunnelling phase would be completed within two months. However, slow excavation, technical hurdles and repeated stoppages have derailed the timeline.

According to officials associated with the project, the TBM is currently progressing at only about one to one-and-a-half metres a day because of safety precautions and engineering challenges inside the tunnel.

Grouting major cause of delay

Sources said continuous grouting inside the tunnel has emerged as one of the primary reasons for the slow pace of excavation.

The process, which is necessary to ensure structural stability and passenger safety, requires frequent halts in TBM operations. These interruptions have prevented continuous drilling and significantly reduced the pace of tunnel construction.

Second TBM Devi Ahilyabai yet to begin work

The second TBM, named Devi Ahilyabai, remains idle inside the 75-foot-deep launching shaft. Under construction norms, the second machine can begin operations only after the first TBM completes at least 50 metres of excavation.

Although all major components of the second machine were installed weeks ago, the delay in the first phase has pushed back its launch schedule. Metro officials now expect the second TBM to begin excavation in the second week of June.

The underground tunnelling project currently involves about 50 technical personnel and 12 senior engineers from Thailand and Indian cities, including Pune, Surat, Mumbai, Delhi and Kanpur.

Public safety and tunnel stability remain the top priorities during excavation. Safety work is being prioritised. The second TBM, Devi Ahilyabai, is expected to begin work in the second week of June."

Dheeraj Shukla, Metro PRO