Making a TBM sing to his tune

With 21 TBMs in operation at various locations across the country burrowing into the unrelenting rock in the Himalayas or digging deep under bustling cities, progress depends on how well the TBM operators are maneuvering these mammoth machines, with exceptional skill and resilience. It is a rare expertise, and one such exponent of making a TBM sing to his tune is TBM Operator, Aruna Giri, at Heavy Civil Infrastructure IC’s Chennai Metro site, bringing to play his 21 years’ rich experience of handling TBM operations, including some overseas assignments.

“TBM operations are crucial for tunnel construction, but they come with many hazards that must be managed,” he says with a serious cast to his features. “The hazards include ground instability, hydraulic and electrical risks, excessive noise, dust generation, mechanical dangers, chemical exposure, falling objects, confined space challenges, and potential flooding,” he enumerates, ticking them off on his fingers. Ground instability is a constant concern, and operators rely on comprehensive geological surveys while implementing robust ground support systems, aware that their decisions can impact the safety of the entire team. Managing the threats of flooding and hazardous gases requires thorough training in dewatering systems and gas detection technologies, ensuring preparedness for any eventuality.

A typical day for Aruna begins with a meticulous inspection of the TBM, and he and his team take immense pride in ensuring that every component of the machine is in optimal condition.

“Regular maintenance of the TBM is non-negotiable,” he says definitively, “and we must always remain vigilant about adhering to operational guidelines, understanding that any lapse could lead to equipment malfunction.”

To mitigate these risks, Aruna and his team implement all the necessary control measures, such as ground monitoring, hydraulic system checks, electrical safety protocols, noise and dust control strategies, mechanical safeguards, proper hazardous material management, tool safety precautions, confined space training, and water management systems. Before breaking ground there is detailed planning during which the tunnel manager prepares an instruction sheet with specific parameters related to the perennial unpredictable geotechnical challenges.

As they traverse the underground terrain, TBM operators act as the vigilant eyes and ears of the operation, constantly assessing the geological environment for ground stability and water levels. Their keen vigilance is crucial in preventing small issues from escalating into major problems; they undergo rigorous training too, to handle emergencies with calmness and precision.

“We never take safety for granted,” says Aruna, adjusting his PPE that he wears like a second skin, “for we are aware that our actions can mean the difference between a safe day at work and a dangerous situation, and therefore, communication is vital in a confined and noisy tunnel.” TBM operators always stay connected with their team using radios, ensuring that everyone is on the same page, a camaraderie that fosters a strong sense of teamwork, where everyone looks out for one another.

Beyond their operational duties, TBM operators also play the role of mentors and trainers for their crew. They believe in cultivating a knowledgeable team and creating an environment where everyone feels confident and prepared for the challenges ahead. “When things don’t go as planned, we are quick to report any incidents or near misses,” interjects Aruna, recognizing that transparency leads to better safety practices and working closely with supervisors to enhance protocols. Familiarity with emergency procedures, including the location of first aid kits and evacuation routes, are essential for speedy and effective reaction in case a crisis arises.

Hailing from Puddukotai, Tamil Nadu, 43-year-old Aruna is married to Maheshwari, a homemaker, and they are blessed with two sons, Kiriprasath and Saisaran.

The role of TBM operators, like Aruna, is a blend of technical expertise, acute safety awareness, and a profound sense of responsibility to their team. They are not merely machine operators; they are safety champions, mentors, and integral players in the success of any tunneling project.