For most of modern history, oceans have acted as natural barriers—dividing nations, slowing trade, and shaping how cities grow. But beneath the waves, a quiet transportation revolution is underway. Infrastructure once limited by geography is now being reimagined through undersea railways.

Undersea rail tunnels—like the Channel Tunnel and Japan’s Seikan Tunnel—proved decades ago that trains could reliably travel beneath the ocean floor. Today, new projects are expanding that vision even further.

Around the world, engineers and governments are investing in undersea railways—tunnels that allow high-speed trains to travel beneath oceans and seas. Once considered science fiction, these projects are now operational, under construction, or actively being planned.

Undersea Rail Is Already a Reality

Japan’s Seikan Tunnel and the Channel Tunnel between the United Kingdom and France proved decades ago that undersea railways are not only possible, but reliable. These tunnels carry passengers and freight beneath the sea every day, reshaping regional connectivity.

Undersea railways are cleaner than short-haul flights, more resilient than bridges, and capable of lasting more than a century. As climate pressures and congestion increase, rail beneath the sea is emerging as a practical solution for future mobility.

What’s Being Built Right Now

China is currently constructing the Jintang Undersea Railway Tunnel as part of the Ningbo–Zhoushan high-speed rail line, while Europe’s Fehmarnbelt Fixed Link will soon connect Denmark and Germany beneath the Baltic Sea. These projects highlight how transportation and technology are converging to solve modern mobility challenges.

The Mega-Projects Still on the Drawing Board

Looking ahead, proposals such as the Helsinki–Tallinn Tunnel and the long-studied Strait of Gibraltar rail tunnel could reshape global affairs by linking regions—and even continents—once separated by water.

Why Undersea Rail Matters

The future of transportation may not rise above the ocean—but run quietly beneath it.

Please leave this field empty

Unlock fun facts & lost history—get The Knowledge in your inbox!

We don’t spam! Read our privacy policy for more info.

Check your inbox or spam folder to confirm your subscription.

Advertisement

I’ve always loved trains.

Not just as transportation, but as an idea: the rhythm of the rails, the slow reveal of landscapes you’d never notice from 35,000 feet, the sense that the journey itself actually matters. That’s why every time I read about Amtrak’s Sunset Limited, especially its long sweep across the Southwest, I can’t help but think the same thing:

I wish I could take the train from Phoenix to Los Angeles—and then ride the Pacific Surfliner.

The Arizona Reality: Close, But Not Quite

Here’s the catch that every Arizona rail fan knows too well: Phoenix doesn’t have direct Amtrak service.

Why I Want to Take the Train from Phoenix to Los Angeles – STM Daily News Podcast

I love trains—and living in Phoenix makes that love complicated. In under a minute, I explain why riding Amtrak’s Sunset Limited to Los Angeles and connecting to the Pacific Surfliner feels like the rail trip the Southwest is still missing. https://stmdailynews.com

The Sunset Limited does cross southern Arizona, stopping in places like Yuma, Tucson, Benson, and Maricopa. Maricopa is technically the closest Amtrak station serving the Phoenix metro area—but it’s about 30 miles south of downtown, meaning a car ride or bus connection is still required.

It’s a small detail, but it matters. Phoenix is the fifth-largest city in the United States, yet if I want to ride Amtrak west to Los Angeles, I first have to leave the city by road just to board the train.

Still, even with that inconvenience, the idea is hard to shake.

Boarding the Sunset Limited

The Sunset Limited is one of Amtrak’s most historic long-distance routes, running from Los Angeles to New Orleans. In Arizona, it cuts through desert landscapes that feel timeless—wide skies, distant mountains, and towns that grew up alongside the railroad itself.

This isn’t high-speed rail. It’s not flashy. It’s slow, deliberate travel, the kind that lets you sit back, watch the desert roll by, and remember that the Southwest was built on rail long before interstates and budget airlines.

From Maricopa or Tucson, the train heads west toward California, crossing into the Imperial Valley before arriving in Los Angeles.

The Real Dream: Connecting to the Surfliner

Advertisement

For me, Los Angeles isn’t the end of the line—it’s the gateway.

Once in LA, I’d love to step off the Sunset Limited and transfer to the Pacific Surfliner, one of the most scenic passenger rail routes in the country. From there, the journey hugs the coastline through Santa Barbara, Ventura, Orange County, and San Diego, offering ocean views that feel almost unreal from a train window.

That connection—from Arizona desert to California coastline—feels like the perfect expression of what passenger rail does best. You don’t just arrive somewhere. You experience the transition.

Why This Matters

This isn’t just about nostalgia or being a train enthusiast.

It’s about options.

Rail travel offers something planes and highways don’t: accessibility, comfort, and a sense of continuity between communities. The fact that Phoenix still lacks direct passenger rail service feels like a missed opportunity—not just for travelers like me, but for the region as a whole.

Every time stories circulate about the Sunset Limited or long-distance Amtrak routes, they remind me that the bones of a better rail network already exist. What’s missing is the will to connect major cities like Phoenix directly into that system.

Someday Soon?

I still hope that one day, taking the train from Phoenix to Los Angeles won’t require a workaround. Until then, the Sunset Limited remains both a real option—and a symbol of what could be.

Because if there’s one thing I know for sure, it’s this:

Advertisement

If I ever get the chance to roll out of Arizona by rail, connect in LA, and ride the Surfliner along the Pacific, I’ll be on that train—camera ready, coffee in hand, watching the country unfold exactly the way it’s meant to be seen.

Coming Soon: Travel Stories from STM Daily News

Travel is more than getting from one place to another—it’s about how we experience the journey. In the weeks ahead, STM Daily News will be sharing new travel stories that explore rail routes, regional history, overlooked connections, and the human side of movement across the Southwest and beyond.

From passenger rail reflections and historic routes to modern transit challenges and scenic journeys worth slowing down for, our upcoming coverage looks at travel as culture, infrastructure, and lived experience.

Coming Soon: Travel Stories from STM Daily News

Travel is more than getting from one place to another—it’s about how we experience the journey. In the weeks ahead, STM Daily News will be sharing new travel stories that explore rail routes, regional history, overlooked connections, and the human side of movement across the Southwest and beyond.

From passenger rail reflections and historic routes to modern transit challenges and scenic journeys worth slowing down for, our upcoming coverage looks at travel as culture, infrastructure, and lived experience.

Follow along at STM Travels as we continue to explore the roads—and rails—that shape how we move.

When the 1997 disaster film Volcano depicted lava erupting along Wilshire Boulevard and referenced blasting during Red Line subway construction, it delivered gripping cinema — but not accurate engineering.

In reality, Los Angeles Metro did not rely on large-scale blasting to construct subway tunnels beneath Wilshire Boulevard and the Miracle Mile. Instead, engineers used tunnel boring machines (TBMs) specifically to avoid the very risks Hollywood dramatized.

Why Blasting Was Avoided

The Wilshire Corridor sits atop historic oil fields, making methane gas pockets a known and serious concern. A deadly methane explosion near Fairfax Avenue in 1985 led to heightened scrutiny of underground construction in the area. Blasting in such conditions could have caused unpredictable gas releases, ground instability, or damage to surface structures.

As a result, Metro engineers chose pressurized, closed-face tunnel boring machines, which allow for:

• Controlled excavation in dense urban environments

• Continuous ground support to prevent settlement

• Integrated gas detection and ventilation systems

These machines grind slowly through soil and rock while installing precast concrete tunnel linings, creating a sealed, gas-resistant structure as they advance.

The Real Engineering Feat

Although Volcano took creative liberties for dramatic effect, the true story of tunneling under Wilshire is no less impressive. Advances in TBM technology and methane mitigation ultimately allowed the Metro D Line (formerly the Red Line/Purple Line) to safely pass through one of Los Angeles’ most geologically complex corridors — without explosions, collapsing streets, or cinematic chaos.

Bottom Line

Volcano remains a memorable piece of 1990s disaster cinema, but its portrayal of subway construction is fiction. The real achievement lies in decades of careful planning, modern tunneling technology, and engineering solutions that quietly reshaped Los Angeles beneath its busiest boulevard.

Related Links:

• LA Metro – D Line (Purple Line) Extension Project
• Engineering News-Record: Tunneling Through Gas and Tar in LA
• Los Angeles Times Archive: Methane Risk and Subway Construction

Dreambreaker: A Pickleball Story — A Closer Look at the Documentary and Its Uncredited Voice