Kavita Shirvaikar writes about Patel Engineering’s fleet of equipment for underground construction.

“The transition from conventional excavation to high-speed, data-driven tunnelling has drastically reshaped our fleet capabilities. By integrating cutting-edge technology into our equipment, we maximize utilization and safely compress tight project timelines.”

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Kavita Shirvaikar, Managing Director,

Patel Engineering.

As a pioneering EPC player with over seven decades of experience in complex underground infrastructure, Patel Engineering does not manufacture equipment; rather, we strategically source, own, and operate one of the most robust and technologically diverse fleets of specialized tunnelling machinery in the country. Our fleet is carefully curated through a combination of proprietary inventory and strategic partnerships with global Original Equipment Manufacturers (OEMs) to handle highly diverse geological conditions.

Our core underground construction fleet consists of five major categories:

Tunnel Boring Machines (TBMs): We deploy heavy-duty, customized TBMs (including an Earth Pressure Balance variant, with a massive diameter of 10 meters) specifically configured for dense urban undergrounds and variable rock strata. These specialized, often imported assets are the crown jewels of our mechanized tunnelling operations.

Computerized Hydraulic Drill Jumbos: For conventional and New Austrian Tunnelling Method (NATM) execution — primarily in tough Himalayan geologies — we utilize highly automated twin-boom hydraulic drilling rigs.

Robotic Shotcrete Sprayers: To ensure immediate structural stabilization post-excavation, our fleet features advanced, remote-controlled robotic concrete spraying arms that eliminate manual hazards at the tunnel face.

Underground Haulage and Mucking Equipment: Our fleet includes specialized Dump Trucks, heavy-duty underground Wheel Loaders, and Tunnel Loaders which are engineered specifically to operate efficiently within heavy constraints of underground space, and high-capacity continuous conveyor systems engineered to operate efficiently within confined underground spaces.

Road Headers: Utilized for mechanized, continuous excavation in specific rock strata, particularly in urban environments or eco-sensitive zones where blasting is restricted.

The transition from conventional excavation to high-speed, data-driven tunnelling has drastically reshaped our fleet capabilities. By integrating cutting-edge technology into our equipment, we maximize utilization and safely compress tight project timelines.

The defining advancements in our equipment include:

Next-gen TBMs with real-time Smart Guidance and Telematics: Unlike older, manually guided models, our modern TBMs feature state-of-the-art laser guidance systems. The power of this technological leap was recently demonstrated at our CIDCO Treated Water Tunnel project, where our advanced TBM setup achieved a national benchmark of 812 meters of tunnelling progress in a single month (January 2026).

Hydraulic Drill Jumbos: These are equipped with multi-arm, heavy-duty hydraulic booms and high-frequency rock drills that provide rapid, stable drilling for blast holes and rock bolting – a massive leap over older, manual pneumatic jackhammer drilling. Modern hydraulic jumbos offer precise boom positioning and superior drilling speed, significantly reducing cycle times while protecting operators inside reinforced cabins.

Robotic Shotcreting: Utilize long-reach, fluid hydraulic spraying arms operated via remote control, backed by high-pressure concrete pumps. These replace highly hazardous and uneven manual nozzle spraying. These mechanized units ensure a more uniform concrete lining thickness, significantly reduce material rebound (waste), and crucially keep the operator well away from the unsupported, vulnerable rock face.

Road Headers: These feature powerful, rotating cutting heads equipped with heavy-duty tungsten carbide picks, paired with integrated dust-suppression water spray systems. Unlike traditional drill-and-blast methods that cause heavy ground vibrations, road headers allow for continuous, low-vibration mechanical excavation. This makes them indispensable for tunnelling safely through weak rock strata and fragile ecosystems without disturbing surrounding structures. We have utilized this technology extensively in the eco-sensitive Himalayan region for the critical excavation activities at the Subansiri Lower HEP.

Tunnel Loaders and Haulage Units: These are built with an extremely low-profile chassis, articulated steering, and high-torque, low-emission engines optimized for confined underground spaces. Older generation earthmovers were too bulky and inefficient for tight tunnel headings. Modern low-profile loaders offer maximum bucket capacity and manoeuvrability in restricted spaces, dramatically accelerating the mucking (waste removal) cycle.

IoT and Telematics Integration: Fleet-wide, our assets are now increasingly ‘digital-ready’ and IoT-enabled. We utilize remote diagnostics and telematics to monitor equipment health, engine parameters, and fuel efficiency in real-time. This shift to predictive, data-driven maintenance is critical for minimizing downtime, especially when operating in remote, challenging terrains where logistics and spare parts sourcing require meticulous planning.