How To Dig a Train Tunnel Under the Hudson River

Summary

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HISTORY This Week: "How To Dig a Train Tunnel Under the Hudson River"

Air Date: February 16, 2026
Host: Sally Helm
Featured Guests:

• Jill Jones (historian, author of "Conquering Gotham: Building Penn Station and Its Tunnels")
• Polly Desjarlais (Content & Research Manager, New York Transit Museum)
• Andy Sparberg (transit historian, retired LIRR manager)

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Episode Overview

This episode dives into the gripping story behind the creation of the railroad tunnels under New York’s Hudson River—one of the most ambitious infrastructure projects of its era. Host Sally Helm unpacks how Alexander Cassatt, an engineer and then-president of the mighty Pennsylvania Railroad, sought to connect his company’s trains directly into Manhattan by tunneling under the river’s notoriously tricky, muddy bed. The episode details the engineering innovations, political battles, personal costs, and ongoing legacy of what became arguably the most important train tunnels in the world.

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Key Topics & Insights

1. The Challenge: Connecting the Northeast by Rail

(03:15 – 13:01)

• The Problem: As of 1900, the Pennsylvania Railroad—the world’s largest corporation—couldn’t bring its trains into Manhattan. The line stopped in New Jersey, and passengers faced an inconvenient ferry ride for the last short distance.
  • “You could see Manhattan from the end of the company’s tracks. You just couldn’t reach it.” – Sally Helm (05:29)
• Competitor Envy: The rival New York Central Railroad, owned by the Vanderbilts, had bridge access—causing deep frustration for Cassatt and his team.
  • “It was very, very galling to the Pennsylvania Railroad that their greatest rival… was the lone railroad whose passengers came in across a bridge.” – Jill Jones (12:10)

2. Alexander Cassatt: Reluctant Visionary

(08:09 – 09:08)

• Cassatt rose from surveyor's assistant to company president. He initially left due to the job's deadly stress (“the killing job”), but was persuaded to return when the company faltered.
  • “The job of president… was so demanding and so stressful that it was literally referred to as a killing job. Presidents of the Pennsylvania Railroad generally died young in office.” – Jill Jones (09:08)

3. Failed Bridge Plans & Eureka in Paris

(13:49 – 18:10)

• Initial Plan: An audacious bridge was proposed, but the $100 million price tag was too steep.
• Breakthrough Abroad: Cassatt, visiting France, is urged to see the new Gare d’Orsay station. He’s captivated by its electric trains running cleanly and quietly through tunnels—sparking the idea to tunnel under the Hudson using electricity instead of smoke-belching steam locomotives.
  • “When he saw this, I mean, he got it immediately.” – Jill Jones (17:47)

4. Tammany Hall and the Politics of Progress

(18:56 – 21:36)

• The railroad’s land acquisition for Penn Station was done secretly to avoid prices being driven up by speculators and to evade the corrupt political machine, Tammany Hall.
• When Tammany’s price ($300,000 bribe) is refused, the project is blocked, sparking public outrage. Mayor Seth Low’s direct lobbying finally tips the scales: “There is not an honest hair in the head of one of them, meaning the alderman.” – Sally Helm quoting The New York Times (20:40)

5. Engineering the Impossible: Mud, Tides, and Dangerous Work

(21:36 – 29:25)

• To manage water intrusion, engineers used compressed air to keep out the Hudson—making the work hazardous, with risk of “the bends” for sandhog laborers.
  • “When you emerged, it was like this hellish, very small space.” – Jill Jones (23:39)
• The Construction Process:
  • Workers operate at the tunnel shield, chipping away mud and rock, assembling iron lining rings, and pushing forward hydraulically—relentlessly inching toward the center from both banks.
  • “Essentially you have workers within this shield… picking away, digging, shovels, pickaxes, whatever.” – Polly Desjarlais (24:17)

6. Crisis: The Hudson Tunnels Begin to Drift

(25:39 – 30:44)

• As the two tunnel segments approach, engineers notice the tunnels “rising and falling” unpredictably.
  • “No one had ever built tunnels through goop like this so long… this was the nightmare scenario always hanging over Ray’s and Cassatt’s head: Would the tunnels be safe?” – Jill Jones (28:20)
• Attempts to fix the movement with heavier rings fail; morale is strained, and Cassatt (already ill) is sidelined.

7. Success: An Exhilarating Breakthrough

(30:44 – 31:26)

• In September 1906, the two tunnel teams meet with astonishing precision: “within 1/8 of an inch.”
  • “No computers, no digital anything. Just slide rules, steam engines and digging.” – Sally Helm (30:53)
• Celebrations erupt, but Cassatt is ill and Samuel Ray, burdened by the drifting mystery, skips the festivities.

8. The Final Puzzle: Tidal Tunnels

(32:00 – 34:13)

• Cassatt dies before completion (“the killing job strikes again”). Ray leads next steps.
• The Mystery Solved: The tunnels were moving in sync with the tidal flow—the “Hudson River” is actually an estuary. Samuel Ray’s solution? Let them flex with the tide. He keeps this a closely guarded secret.
  • “It was just absolutely kept silent.” – Jill Jones (33:59)

9. Legacy: Penn Station, Urban Growth, and Ongoing Challenges

(34:45 – 37:47)

• Penn Station, opening in 1910, transforms New York, connects the city up and down the East Coast, and ushers in the age of electric train travel.
• The original Beaux-Arts station is demolished in the 1960s; the tunnels persist and now carry over 200,000 people daily.
• Superstorm Sandy (2012) exposes the fragility of century-old infrastructure—repairing the tunnel system is now the biggest public works effort in America.
  • “The tunnels basically… still have to go into the same river, then they’ve got to get into the same station that’s still there. So it’s a project on the scale of the original project.” – Andy Sparberg (37:35)

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Notable Quotes & Moments

• On the precise tunnel connection:
  “The tunnels have met within 1/8 of an inch. It's just so, so incredible.”
  — Jill Jones (30:44)

• On the importance of the tunnels today:
  “It is the lifeblood. This is a very overused term and it is a bit clichéd, but it is true that transportation powers this region. We can't do what we do without it.”
  — Polly Desjarlais (36:20)

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Timeline of Major Segments

| Timestamp | Segment | |---------------|-------------| | 03:15 | Problem introduction: Hudson River as barrier, Penn RR ambitions | | 08:09 | Background on Alexander Cassatt’s rise and motivations | | 13:49 | The failed bridge plan and Cassatt’s Paris inspiration | | 18:56 | Political maneuvering and Tammany Hall | | 21:36 | Tunnel engineering challenge: compressed air and hazardous work | | 25:39 | Discovery of tunnels drifting under the river | | 30:44 | Breakthrough: Both tunnel crews meet under the river | | 32:00 | Cassatt’s death and Ray’s solution to the tidal movement | | 34:45 | Impact of the tunnels’ opening and Penn Station’s legacy | | 36:20 | Superstorm Sandy’s damage and modern rehabilitation plans |

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Episode Tone

In true “HISTORY This Week” fashion, the episode strikes a balance between dramatic storytelling and deep historical insight. The narrative is brisk but rich, full of quirky period details, direct speaker quotes, and a sense of awe about technological ambition and urban change. The hosts and guests blend clear explanation with storytelling, making the material accessible and vivid even for listeners unfamiliar with railroads.

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Takeaway

The Hudson River tunnels stand as a testament to American ingenuity—conceived by a man haunted by the ghosts of failed predecessors, realized through global inspiration and local grit, and continually vital long after the era that birthed them. Despite engineering triumphs and political machinations, the basic natural challenges remain: New York’s geography, human ambition, and the relentless tide.

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Transcript

[Sally Helm]

Hey History this Week listeners, we have something very exciting to share. This podcast has been going since 2020, but for the first time ever, we are taking it live. If you are in the New York City area, please join us for a live episode at the Tenement Museum in Downtown Manhattan. On Wednesday, March 4th at 6:30pm, I will be in conversation with historian Tyler Annbinder exploring the history of Irish immigration to the United States, cutting through some of the most common myths and looking closely at how Irish immigrants actually navigated life, work and assimilation in America. This is history where it happened in one of the most meaningful spaces in the city and we would love to see you there. We will drop a link with all the details in the episode description and you can also find the [e-mail] Hope to see you there.

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[Andy Sparberg]

The History Channel Original Podcast.

[Sally Helm]

History this week, February 14th, 1905 I'm Sally Helm. There is one thing standing between Alexander Cassatt and greatness. Cassatt is the president of the Pennsylvania railroad. As of 1900, it is the largest corporation in the world. But his trains can't get into one of the largest cities in the world, New York. They get to New Jersey and can't go any further. Passengers have to get off and catch a ferry to get into Manhattan. And for Alexander Cassatt, this is galling, undignified. It's not befitting of the great Pennsylvania Railroad. He wants to be able to bring his trains into New York. This will allow him to transport commuters, sure, but also to ultimately connect all of what is today called the Northeast Corridor. It'll become a vital link in a continuous rail line from Florida to Quebec. The one thing standing in his way is the Hudson River. The Hudson river in this spot is less than a mile wide. It shouldn't be so difficult to cross. And Alexander Cassatt knows how he wants to do it with an underground tunnel. Unfortunately, it turns out to be very, very hard to build a tunnel under the Hudson. The earth is goopy, but there are also random boulders scattered in the mud leftover from glaciers 18,000 years earlier. It is an engineering nightmare. And on this day, February 14th, all of those problems become very, very public. Around 11:00am, one of the men working underground detonates a stick of dynamite. That is nothing out of the ordinary. These men, known as the sand hogs, have dynamite as one of the tools in their arsenal, one of the ways to get through all that gloopy earth underneath the Hudson. But this time, the ground above them starts rumbling, making a muttering noise. They start to back away and mud begins to pour through the walls of the tunnel. Then, On the surface in the train yard, two men are pulling coal along some tracks when suddenly they see those tracks begin to disappear into the earth. They leap from their posts just as a whole locomotive is swallowed up by a 50 foot wide single cold. Thankfully, and surprisingly, no one is killed. The men underground manage to escape. The Weehawken sinkhole is less a tragedy and more just an embarrassment for the Pennsylvania Railroad, one of the largest corporations in world history, being stymied by mud. Poor Alexander Cassatt is said to have remarked in frustration that you could see Manhattan from the end of the company's tracks. You just couldn't reach it. We must, he said, find a way to cross today. Train tunnels under the Hudson. How did an engineer turned horse breeder turned corporate executive overcome silver, seemingly unsolvable technological problems to build these underground tunnels? And how did they become arguably the most important train tunnels in the world? The Pennsylvania Railroad was this famous, enormous corporation. In 1900, the only organization in the country with a bigger budget was the federal government. And the Pennsylvania Railroad was said to be a real, actual meritocracy.

[Jill Jones]

Alexander Cassatt begins at the bottom, like everyone did in the railroad.

[Sally Helm]

That's Jill Jones, a historian who wrote a book about this tunnel project. She said Cassatt started out at the company as a surveyor's assistant, earning a dollar a day.

[Jill Jones]

But he had a meteoric rise because the man was brilliant.

[Sally Helm]

He had a superhuman memory. He was known to reel off obscure bookkeeping facts off the top of his head. He was also good with machines. One of his longtime managers said that sometimes Cassatt could be found running a train all on his own while its engineer took a break. Cassatt has a storied career at the company. But at age 42, as Vice President of the railroad, he retires to raise and breed horses. Pretty good life. And the alternative, becoming president of the Pennsylvania Railroad. It did not look all that appealing.

[Jill Jones]

The job of president. Pennsylvania was so demanding and so stressful that it was literally referred to as a killing job. Presidents of the Pennsylvania Railroad generally died young in office. So Cassatt left and a man named George Roberts was president and he died. Another man took his place. He died. And the railroad was really struggling, basically because America was booming and there was so much freight and they just, they were overwhelmed. So in 1899, the railroad comes to him and asks him to come back as president.

[Sally Helm]

Basically, Alexander, you're our only hope. The board literally goes to find him in the field where he is exercising one of his horses. And he agrees. But he says he'll need free reign to improve things, to expand. And pretty immediately, he directs his focus to a mile wide river, the Hudson. Cassatt wants his trains to cross it. America's biggest and most important city at the time, New York has some geographical features that it can be kind of easy to forget about.

[Polly Desjarlais]

We have this wackadoodle place where we're.

[Sally Helm]

On all these islands, that is Polly desjarlais Content and research manager at the New York Transit Museum, reminding us that Manhattan is an island, one of several that makes up New York City at.

[Polly Desjarlais]

This period of time.

[Jill Jones]

This is the thing.

[Polly Desjarlais]

How are we connecting these places? You know, ferries do it for a while.

[Sally Helm]

Yeah. At this point, if you were a passenger on a Pennsylvania Railroad train and you wanted to travel to the biggest city in the country, you would have to get off in New Jersey and hop on a ferry with all your stuff. With all the other passengers, you'd navigate the crowded river waters dodging huge steamships and tiny sloops and delivery boats and pleasure yachts.

[Jill Jones]

And one of the great surprises to me when I worked on this book was to realize how incredibly crowded the waters were.

[Sally Helm]

But you make it through and then you get off at west street, which.

[Jill Jones]

Was just total bedlam, you know, muddy and messy. And the whole thing did not comport with the way the Pennsylvania Railroad saw itself.

[Sally Helm]

At least they weren't the only ones. The other railroad companies also had to dump the passengers off in New Jersey and put them on a ferry. All the other companies, except for one.

[Jill Jones]

It was very, very galling to the Pennsylvania Railroad that their greatest rival, the Vanderbilts and the New York Central Railroad was the lone railroad whose passengers came in across a bridge.

[Sally Helm]

Across a bridge. Much more dignified. The Vanderbilts and their New York Central Railroad had built a short bridge crossing into Manhattan from the north. Now the New York Central had nowhere near the national network of the Pennsylvania Railroad. And in some ways their trains were nothing to be jealous of.

[Jill Jones]

These are coal fire steam locomotives and if you have not been around such a train, you don't have a clue what that pollution is like.

[Sally Helm]

These trains would billow black smoke as they chugged along, getting in everyone's eyes. The Vanderbilt trains did briefly go underground into short tunnels right before pulling into Grand Central Station. But this could actually create another problem.

[Andy Sparberg]

They were billowing smoke, they were very noisy.

[Sally Helm]

That is Andy Sparberg, transit historian and 25 year veteran of the Long Island Railroad. He told us about one particularly horrible incident in these tunnels.

[Andy Sparberg]

One train rear ended another because of the lack of visibility. It missed a signal and plowed into the rear of a train that was stopped ahead. Fifteen people were killed.

[Sally Helm]

These trains produced so much pollution that they would cloud up the tunnel, making it impossible to see what was in front of them. Alexander Cassatt has a solution to all of this. A grand bridge across the Hudson. 14 train tracks plus lanes for pedestrians and carriages. 500 foot towers, a span suspended 185ft in the air to allow huge ships to pass underneath. It would be the largest bridge in the world. Engineering News wrote. The grandeur of the project is almost appalling.

[Jill Jones]

The next year, the entire thing is off.

[Sally Helm]

Yeah, the price tag was $100 million. Turns out that's too high. It's now the summer of 1901, and Cassatt is at a loss. He doesn't know how to get his trains across the Hudson, so he takes a trip to France, which is supposed to be a vacation, but turns out to be a work trip. It is there that he will find his solution. Why have I asked my H Vac guy I found on angie.com to change my grandpa's trachea tube? Because I was so amazed by how.

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[Sally Helm]

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[Sally Helm]

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[Sally Helm]

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[Sally Helm]

Alexandre Cassatt goes to France to visit his sister Mary Cassatt, the now legendary impressionist painter.

[Jill Jones]

When he is identified today, he's identified as her brother, which would have been astonishing to people at that time because she did not register at all.

[Sally Helm]

While he's there, Alexander gets a message from his vice president, Samuel Ray.

[Jill Jones]

He gets A telegraph from Ray saying, you know what? Go look at the. The Gare Quai d'.

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[Sally Helm]

The d' Orsay station had just opened in Paris. Today it has actually been turned into an art museum that houses some Mary Cassatt paintings. But back then, it is a massive palatial train hub. Seven limestone archways serve as entrances. Sculptures adorn the exterior. Lion's heads, laurel leaves, and inside, there is no smoke.

[Jill Jones]

When he saw this, I mean, he got it immediately.

[Sally Helm]

The trains pulling into this station are all electric, and they're coming through tunnels along the Seine river without blinding their conductors with billowing black smoke. I, Alexander Cassatt sees his future.

[Jill Jones]

It's like we, we could come into Manhattan under the river with these electric locomotives.

[Sally Helm]

Cassatt springs into action. On his way home from Europe, he recruits Charles Jacobs, an upbeat Englishman and one of the world's former foremost tunneling experts. Along with his vice president, Samuel Ray, they begin to plan to connect the two coasts of the Hudson with an underground tunnel.

[Jill Jones]

They'll start on both sides of the river simultaneously, and they will come at each other to meet in the middle, far below the riverbed.

[Sally Helm]

This tunnel will lead to a new train station as monumental as the one in Paris. It'll be named after the railroad, Penn Station. At first, the company is operating in secrecy, partly because they're buying up all this land for Penn Station and they want to get a good deal. People might demand more if they know what it's for, but also because they want to stay beneath the notice of the vast political machine that runs New York, Tammany Hall.

[Jill Jones]

Tammany was just. It was a never ending search for bribes and boodle and, you know, rake off and whatever.

[Sally Helm]

Tammany hall has been in power for a long time, but they have actually just recently suffered a setback. They were caught rigging the city's ice market. Ice is the main method of refrigeration at this time. And when people find out that Tammany is making money off ice while the common man's food spoils, there's an uproar. So much so that New York elects a mayor who isn't in Tammany's pocket, a reformer named Seth Low. But Low doesn't control the city's board of aldermen, aka the 40 Thieves. It actually has 79 members. And they're not all thieves, but Tammany has a majority in their pocket. And the Pennsylvania Railroad will need permission from the 40 Thieves to build their station. When they do go public, Tammany essentially.

[Jill Jones]

Announces Their price, they let it be known that the bribe or the boodle would be $300,000.

[Sally Helm]

But Alexander Cassatt is not having it. He's like, I am not paying that. This project is going to be a huge, huge deal for New York. Like it would be absurd to kill it. The proposal goes before the board of Aldermen and they vote it down. No boodle, no approval. But Tammany remembers a little bit on the outs and people get really mad about this. The New York Times, there is not an honest hair in the head of one of them, meaning the alderman. Scientific American, one of the most shame based exhibitions of political tyranny that ever disgraced the city. And Cassatt turns up the pressure.

[Jill Jones]

The Pennsylvania Railroad has said, look, if you don't give us this franchise by this state, that's it. Because we have invested all this money and we cannot sit around. So if you don't give us this, we're gone and we're sorry. But you know, we were very straight.

[Sally Helm]

With you and New York City really does want this project. The reform minded mayor Seth Low takes some of the aldermen out on his personal yacht to woo them. He writes each of them a heartfelt letter for their yes votes. And on December 16, 1902, the Board of Aldermen needs to vote again. And just enough of the 40 Thieves Break ranks with Tammany. The board approved proves Alexander Cassatt's audacious plan. I feel like today building an underwater tunnel sounds like, oh yeah, I don't know, we probably have technology to do that. But this was actually so, so hard. I mean, think about it. The tunnel is underwater. How do you build that without getting flooded? What they did was pump compressed air into the tunnel as they built it. So the water is pushing in, but the air is pushing back out. That worked, but it made for a very specific and dangerous environment. If you want access to the Hudson river tunnel site in 1903, three first you take an elevator.

[Jill Jones]

You walked out and into the airlock where you would sit for 15 minutes while it filled up with compressed air and you got acclimated.

[Sally Helm]

If you didn't do that, you might end up get the bends like what scuba divers can get. If you go down too quickly, you can get intense ear pain and brain fog. If you come up too quickly, dangerous bubbles can form in your blood.

[Jill Jones]

When you emerged, it was like this hellish, very small space.

[Sally Helm]

The workers, the sandwich hogs, are pushing the tunnel forward inch by inch.

[Jill Jones]

It was really wet, really muddy and really chaotic under the Tunnels. I mean, it was a very controlled, orchestrated chaos.

[Sally Helm]

At the very front of the tunnel space is this giant piece of machinery called the great head shield. It almost looks like a piece of, of a rocket ship or something.

[Polly Desjarlais]

Essentially you have workers within this shield.

[Sally Helm]

Polly Desirelais.

[Polly Desjarlais]

They are picking away digging, shovels, pickaxes, whatever.

[Sally Helm]

These compartments open up at the front of the shield, letting the workers clear all the silt and rock. Once that's out of the way, they install these rings, sections of cast on.

[Polly Desjarlais]

Iron, which was the tunnel lining. And then they would sort of rivet all of those together.

[Sally Helm]

Once the tunnel walls are in place, the great head shield activates these huge hydraulic jacks and lurches forward 2 and 12ft. And the workers start the whole process over. And there's really no margin for error because remember, they're building both sides of the tunnel at once from opposite shores and they're going to meet in the middle. So if the alignment gets a little off, they're going to be in big trouble. And in the spring of 1906, the engineers noticed something. Samuel Ray, vice president of the railroad, writes a secret memo to his boss, Cassatt.

[Jill Jones]

He's really worried because they can tell the tunnels are rising and falling and they don't know why.

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[Sally Helm]

Spring 1906. The tunnels under the Hudson are mysteriously shifting slowly oscillating up and down in the muddy riverbed. And nobody knows what's going on. Not Cassatt, not Ray, not even Charles Jacobs, the tunnel savant. It looks like the tunnel haters might have had a point.

[Jill Jones]

Many, many people, engineers and so forth, basically said, you cannot safely build railroad tunnels that will be carrying 700 ton trains in tunnels like this. No one had ever built tunnels through goop like this so long, et cetera, et cetera, et cetera. So you know, this was the nightmare scenario. Always hanging over rays in Cassad's head. Would the tunnels be safe? And when they saw them moving up and down, I mean, that was really disturbing.

[Sally Helm]

They're like, okay, we gotta figure this out.

[Jill Jones]

Well, maybe because, you know, the, the riverbed that they're tunneling through is so soupy, they need to have heavier rings.

[Sally Helm]

The rounded rings, these pieces of the tunnel that they're slowly putting in place. Maybe they need to be stronger.

[Jill Jones]

So that's the next thing they do, they make heavier rings.

[Sally Helm]

That doesn't work. The tunnels are still drifting.

[Jill Jones]

Cassatt's under a lot of stress. He's up in Bar harbor where he has a so called cottage.

[Sally Helm]

It's actually a very nice big house. But what is supposed to be a vacation turns into another obstacle for Alexander Cassatt.

[Jill Jones]

He gets whooping cough from his granddaughter.

[Sally Helm]

Cassatt is stuck in Maine, recovering. Meanwhile, the two sides of the tunnel are getting closer and closer until the big day finally arrives. September 1906. The two sides of the tunnel are set to meet in the middle of the Hudson River. The engineers have tried to account for the drifting in their calculations. And today they'll see if it worked. The sand hogs on the New York side push a pipe through the front of their tunnel shield. And sure enough, they can see and hear the New Jersey sand hogs on the other side. The Jersey guys send a box of cigars back through the pipe, conceding that the New Yorkers had beat them to the middle by a few feet. And when the two great head shields actually make contact.

[Jill Jones]

The tunnels have met within 1/8 of an inch. It's just so, so incredible.

[Sally Helm]

No computers, no digital anything. Just slide rules, steam engines and digging. Of course, the crew has to celebrate. It's very cute.

[Jill Jones]

The engineers, the reporters, the sandhogs, they all march across and emerge in Manhattan, whereupon they go to Delmonico's and have a riotous celebratory lunch involving a lot of throwing of bread and food and what have you.

[Sally Helm]

But a few people are conspicuously missing. Samuel Ray, the VP of the railroad, is too anxious about the tunnel drifting mystery to attend. Even though the two sides are now connected, they still aren't supposed to stabilized. And Alexander Cassatt is still up in.

[Jill Jones]

Bar harbor and, you know, next thing you know, on December 28, 1906, the seventh president of the Pennsylvania Railroad dies in office.

[Sally Helm]

The killing job strikes again. Alexander Cassatt is 67 years old. Samuel Ray doesn't take over as Pennsylvania Railroad president because at this rate, who would want to? But he does take charge of the tunnel project, and he is determined to solve this tunnel drifting mystery. Alexander Cassatt won't live to see a train pass underneath the Hudson, but Ray is going to make it happen. He and his crew put in a special gauge to monitor the movement more closely. And it all becomes clear. It's such a.

[Jill Jones]

It's so logical.

[Sally Helm]

The tunnels are moving with the tides. The Hudson River, Alexander Cassatt's great adversary, is kind of not really a river at all in this area. It's more of an estuary. So the tides of the Atlantic Ocean are pushing the water back and forth. When the tides are highest, the tunnels are lowest because the weight of the water is literally pressing them further down into the earth.

[Jill Jones]

It's so amazing, you know, that it can move these incredibly heavy tunnels up and down.

[Sally Helm]

Samuel Ray now has to figure out what to do. And he decides to do nothing. Rather than spend millions to anchor the tunnels to the bedrock, he'll just let them move like a suspension bridge or a skyscraper flexing in the wind. He looks into it and he feels confident that it will be safe. But nevertheless, he doesn't advertise this decision.

[Jill Jones]

When I was researching this book, I realized this was the great secret about the tunnels. No one ever knew any of this. It was just absolutely kept silent.

[Sally Helm]

And then they start sending test trains through and the tunnels seem to be holding.

[Jill Jones]

Can you imagine what Ray must have felt? I mean, there was no way to know until the trains went through. And I mean, honestly, probably until the station was open and hundreds of trains were going through. And months had gone by and years had gone by to really, really know that the tunnels would not crack.

[Sally Helm]

The tunnel. Tunnels do not crack. Penn Station opens to the public in November of 1910. A monument of steel and glass and pink granite. The tunnels are open. The Pennsylvania Railroad has crossed the Hudson.

[Jill Jones]

It really transforms the whole area of New York. Really opens it up to people and makes people's lives a lot easier, easier.

[Mint Mobile Sponsor]

And a lot better.

[Sally Helm]

What was once considered rural land in the surrounding regions now has direct rail access to the biggest city in America. In 1917, the Hellgate Bridge opens, establishing that continuous rail line from Florida to Canada. Plus, the new trains are electric, clean, no more spewing black smoke. The United States has entered the modern age of train travel. The monumental Penn Station is actually torn down in the mid-1960s to make way for Madison Square Garden. And in 1968, the Pennsylvania Railroad ceases to exist altogether, ironically merging with Vanderbilt's New York Central. Today, the reworked Penn Station exists entirely underground. It is the busiest rail station in North America. The Hudson river tunnels are now 115 years old. They carry more than 200,000 passengers every day. Here's Polly Desjerlet.

[Polly Desjarlais]

It is the lifeblood. This is a very overused term and it is a bit cliched, but it is true that transportation powers this region. We can't do what we do without it.

[Sally Helm]

But these old tunnels are a little the worse for wear. Here's andy Sparberg.

[Andy Sparberg]

In 2012, Superstorm Sandy damaged him terribly because water rushed in and went into the tunnels. And that's brackish. Salt water damaged the electrical components, the signals, the roadbed, and it took a while to make some roof rudimentary repairs. But eventually, you know, those tunnels need to be rebuilt.

[Sally Helm]

At this point, the tunnels are deeply embedded into the economy. Patchwork fixes have kept them going, but their failure would be a catastrophe. And the project to fix them has started. It is the largest public works project in America. The Trump administration has been locked in a legal battle in an attempt to withhold the funding. But if the money is there, the plan is to build two new tunnels next to the old ones. And many of Alexander Cassatt's challenges still apply.

[Andy Sparberg]

The tunnels, basically, they still have to go into the same river, then they've got to get into the same station that's still there. So it's a project on the scale of the original project. No question about it.

[Sally Helm]

Turns out it's not that much easier to build tunnels in the Hudson. 125 years later. The riverbed is still goopy, and there are now even more buildings and pipes and subways to work around when you're tunneling into Penn Station. But once the two new tunnels are finished, workers will turn their attention to rehabilitating the old ones. If all goes according to plan, the tunnels that first opened in 1910 should be ready again by 2038.

[Announcer]

Attention please.

[Sally Helm]

This is a special announcement for passengers.

[Announcer]

Traveling on Amtrak's train number 63 and.

[Jill Jones]

Crossing the border into Canada.

[Announcer]

Please present your train tickets and travel.

[Sally Helm]

Documents to the Amtrak represent this is our first episode of the new season of History this week, so you can expect more never before heard stories just like this one hitting your feed every Monday. And thank you so much to all of our listeners. Some of you have been with us all six years of the show, and some of you are new. Welcome History this Week is a Back Pocket Studios production in partnership with the History Channel. To stay updated on all things History this week, sign [e-mail] and follow us on Instagram historythisweekpodcast. If you have any thoughts or questions, send us an [e-mail] Special thanks to our Polly Desjarlais, content and research Manager at the New York Transit Museum Jill Jones, historian and author of Conquering Building Penn Station and Its Tunnels and Andy Sparberg, retired Long island railroad manager, transit historian and author of From a Nickel to a the Journey From Board of Transportation to mta. This episode was produced and sound designed by Ben Dickstein, who loves trains. It was also produced by me, Sally Helm. I like trains too. For Back Pocket Studios. Our executive producer is Ben Dickstein from the History Channel. Our executive producers are Eli Lehrer and Liv Fiddler. Don't forget to follow rate and review History this week, wherever you get your podcasts and we'll see you next week.