Somewhere beneath the hills of the Western Ghats and the mountains of the Himalayas, India is in the middle of one of the most ambitious tunnelling programmes anywhere in the world — metro lines threading under some of the densest cities on the planet, highway tunnels cutting through terrain that used to mean hours of switchback driving, hydropower tunnels carved through rock that took decades to fully map. It's the kind of engineering effort that rarely makes headlines when it goes right, which is most of the time. And according to Dr Sandeep Potnis, Director, Centre of Excellence for Tunnelling and Underground Construction, MIT-WPU, Pune, the quiet part of that story — the codes, the instrumentation, the accumulated expertise — is the part actually worth paying attention to.

A Decade of Genuine Progress
Ask Potnis to put India's tunnelling programme in global context, and he doesn't hesitate: the country is now executing some of the largest highway, railway, metro and hydropower tunnel projects anywhere in the world. That's not a modest claim, and it's not a recent fluke either — it's the product of roughly a decade of sustained investment in underground infrastructure, at a scale that puts India in genuinely rare company internationally.

What makes that scale-up sustainable, rather than just impressive on paper, is that India built its own rulebook alongside it. IRC codes, MoRTH specifications, IS codes — a full technical framework already exists, drawing on decades of international best practice from tunnelling programmes in Japan, Switzerland, Austria and Norway. India isn't improvising its way through unfamiliar terrain. It's applying an established, continuously updated body of engineering knowledge to some of the most geologically demanding ground on Earth.

The Instruments Are Already in the Ground
One of the more encouraging things Potnis points to is how far instrumentation has come on Indian projects already. Convergence measurements, extensometers, piezometers, strain gauges, load cells, settlement markers — tools that used to be the exclusive domain of a handful of flagship international projects — are now genuinely common across India's metro, railway, highway and hydropower tunnelling work. That's a meaningful shift. It means engineers aren't just building tunnels; they're building tunnels that talk back, generating real-time data on how the ground around them is actually behaving.

The next frontier, in his account, is extending that same instrumentation to portal slopes and muck disposal areas — and the technology to do it already exists and is proven elsewhere: slope radar, GNSS satellite positioning, LiDAR, drone-based photogrammetry, rainfall alert systems, automated dashboards that flag a problem before a human inspector would spot it on a routine visit. None of this is aspirational technology. It's equipment already deployed successfully on tunnelling programmes abroad, waiting to be scaled up domestically — which is a considerably easier problem to solve than developing new science from scratch.

Engineers Who Can Read a Hillside Like a Book
There is something almost reassuring in how precisely Potnis can describe the early warning signs of slope trouble — fresh tension cracks at a crest, a retaining wall starting to lean, a drain running muddier than it should, groundwater rising faster than expected. This isn't guesswork. It's a discipline with an established vocabulary, and Indian geotechnical engineers are increasingly fluent in it, trained to catch these signals well before they become the kind of headline-making event that gets a project shut down.

That expertise is exactly what institutions like MIT-WPU's Centre of Excellence exist to build out further — training the next generation of tunnelling engineers not just in how to bore through rock, but in how to read a slope, sequence a construction site safely, and treat drainage and debris management with the same rigour as the tunnel itself. It's a sign of a discipline maturing: India isn't just building tunnels anymore, it's building the institutional expertise to keep building them more safely, one graduating class at a time.

Safety and Speed Are Turning Out to Be the Same Goal
Perhaps the most useful reframe in the entire conversation is Potnis's insistence that safety and speed were never actually in competition. Unsafe shortcuts, in his telling, don't save time — they just relocate the delay downstream into investigations, legal proceedings and rebuilding work, all of which cost far more time than the safety measure they were meant to skip. Projects that build in clear rainfall thresholds, defined stop-work triggers, and independent geotechnical review aren't slower projects. They're the ones that don't lose months to an entirely avoidable setback.

That's a genuinely optimistic insight, because it means the industry doesn't face a real trade-off between ambition and caution. The fastest way to keep India's tunnelling programme moving at the pace its infrastructure goals demand is, if anything, to get more disciplined about the unglamorous fundamentals — sequencing, drainage, monitoring — not less.

Learning Fast, and Learning for Good
Every engineering discipline advances partly through its failures, and tunnelling is no exception. What's notable about India's recent experience — Silkyara in 2023, and more recent incidents in fragile terrain like the Western Ghats — is how directly they're feeding back into a clearer, more specific list of priorities: climate-adjusted rainfall design, automated slope monitoring extended beyond just the tunnel bore, independent safety audits, and an observational method that lets construction respond to what a site is actually showing rather than what the original design assumed.

None of that requires India to invent new engineering science. As Potnis puts it, the standards and the knowledge are already there — what's improving, project by project, is the discipline of applying them consistently, everywhere from the tunnel face to the muck disposal site a kilometre away that rarely gets the same attention. That's the kind of gap that closes with better habits and better instrumentation, not with a decade of new research. And on the evidence of how far India's tunnelling capability has already come, it's a gap the industry is closing.

What Comes Next
For the young engineers Potnis trains, the lesson he wants embedded early is a simple one: a tunnel is a system, not just a hole in the ground. The portal, the drainage, the access roads, the retaining structures, the muck disposal — all of it deserves the same seriousness as the bore itself. Engineers who learn to see the whole picture, rather than just the most visually impressive part of the project, are the ones building the next decade of India's underground infrastructure — one that draws on genuinely world-class technical standards, a fast-growing base of monitoring technology, and a generation of engineers being trained to treat every part of a tunnel project, however unglamorous, as engineering that matters.