[narrator] This is the Glacier Express... ...an extraordinary train journey that winds through the mountains of Switzerland, like no other.

Beginning in the southeast of the country at St. Moritz... ...it travels 290 kilometers along alpine peaks, over treacherous gorges, and through mountain ranges... ...ending underneath the world-famous Matterhorn at Zermatt.

Filmed from above, this series showcases some of the most incredible railways on Earth.

We'll gain a unique aerial insight into these remarkable trains and the extraordinary landscapes they pass through, revealing the technology that built them, and the dedicated people who keep them running.

We'll uncover the culture, the history, and the engineering that makes these truly Epic Train Journeys From Above.

Landlocked in Central Europe, Switzerland is dominated on its southern border by the Eastern Alps.

This is Western Europe's most mountainous country, over 200 peaks, of which 48 top 4,000 meters.

Little wonder, then, that tourists come from around the world to walk, ski and climb in this majestic scenery.

[whimsical music] Many of them come here, to St. Moritz.

Made famous as a spa resort in the 19th century due to its mineral springs and around 300 days of sunshine a year, St. Moritz is the birthplace of alpine tourism, and twice hosted the Winter Olympics.

It's also the starting point for one of only four railways in the world to be granted UNESCO World Heritage status... ...the Glacier Express.

Now we have a temperature from 20 degrees minus.

Very cold!

Carsten Fischer is in charge of the train today.

He will cover the first part of the eight-hour journey.

Before, I was a bus driver in St. Moritz.

I prefer driving the train.

It's a dream, uh, while I was a child.

Finally I got there, and I love it.

[chuckles] Before the passengers board, the engine needs to be coupled to the carriages.

[beeping] [beeping continues] [indistinct radio transmission] [beeping, brakes hiss] So, now my colleague is controlling if the brakes are on the wheel.

These lines are critical.

They carry hydraulic air for the brakes and power for the heating.

A failure could be catastrophic, so there's a back-up for each line.

Now we are ready for our take-off.

[chuckles] [air hissing] OK. [exhilarating music] In an average year, the train hosts up to a quarter of a million passengers, 80% of whom travel from abroad.

From above, this breath-taking route has many challenges ahead.

From St. Moritz, the line travels 291 kilometers west to Zermatt, crisscrossing five alpine valleys.

Keeping the train running in all weather requires a dedicated team, working tirelessly to ensure that nothing interferes with passengers' enjoyment of the spectacular journey.

Preparations for today's trip began long before the train departed from St. Moritz.

Overnight, heavy snowfall has blocked the route.

Keeping it clear at all times is the job of maintenance manager Guido Monn.

Thirteen kilometers of track are currently blocked, so Guido is using brute force to clear them, a heavy-duty, 25-tonne snow blower.

Four blades cut through the snow, using centrifugal force to blast it away from the tracks.

But Guido has to keep a close eye on where it's redeposited.

Virtually the whole Swiss rail network is electrified, largely powered by renewables.

With 15% of the population relying on trains to commute to work, keeping these tracks open is important for the economy, as well as for tourists.

This locomotive is one of the few in Switzerland that's diesel powered.

[dramatic music] Clearing these deep snowdrifts means constant vehicle maintenance.

It's backbreaking work, but Guido knows it's essential for the railway and its passengers.

As dawn approaches, Guido and his team have cleared the line.

With unhindered tracks, the Glacier Express can make headway.

It's now passing Celerina, a 16th-century village which has a thriving jazz scene.

So much so, it's known as the Swiss New Orleans.

At a top speed of just 88 kilometers per hour, this train isn't built to be fast.

Instead, its four electric motors are all about traction, the ability to haul heavy carriages up steep inclines.

Over the route, the line climbs a combined vertical height of almost 2.4 kilometers.

It was constructed 130 years ago to attract tourists to the spa hotels which lined the Engadin Valley.

At the time, few were willing to make the 14-hour horse and coach trip through the mountains.

A train could make the same journey in just two hours.

However, planning the route, engineers faced a problem... ...the Crasta Mora mountain range.

It was impossible to go over, and circumventing it would've added hours to the journey, so a bold decision was made... We're now entering the Albula Tunnel.

...to tunnel through the entire mountain.

In 1898, 1,300 men set out to dig through nine kilometers of solid rock.

One and a half kilometers in, they struck multiple underground springs, creating mudflows that completely blocked the tunnel.

It took over a year to painstakingly divert the water through pipelines.

The work was so dangerous that 16 men lost their lives in its four-year construction.

A monument to the workers' perseverance, the Albula, is currently the highest mainline tunnel in the Alps.

But that's about to change.

Now, because the tunnel is too old, we are building a new tunnel.

It's on the right side of our terrain.

The new tunnel is due to open in 2024.

Using modern equipment and over 700 tons of explosives, it's nonetheless taken workers nine years to bore.

The next stretch of the journey leads down to the Albula Valley, another massive challenge for the engineers building the line.

Along its breath-taking journey through the Swiss Alps, the Glacier Express voyages the length of the Albula Valley.

The Albula River is a tributary to the Rhine.

These waters flow over 1,200 kilometers through Austria, Germany, France and the Netherlands, ending up in the North Sea.

But first, the river, and the trainline, must plummet over 400 meters in just over four-and-a-half kilometers.

For a train, such an extreme drop puts immense pressure on brakes and wheels.

A crack or a dent could cause a derailment.

Sven Moser's job is to make sure that doesn't happen.

He's responsible for testing and repairing the wheelsets for the entire fleet, here at the main workshop in Landquart.

Carriages are inspected annually, and Sven has just an hour to service the wheels on each one.

[wheels clanking] In the past, a whole team was needed to remove the wheels before they could be inspected and repaired.

Now, engineers have developed a lathe which can measure the roundness of the wheels, identify faults, and correct them.

This means Sven can do the work singlehandedly.

The challenge is that each wheel must be identical to the opposite one.

Non-identical wheels cause uneven loading, which can eventually lead to mechanical failure.

Sven is happy this carriage is safe and ready to re-enter service for another year.

But even with the best brakes and smoothest wheels, the Glacier Express couldn't make a direct descent down the Albula Valley.

It's simply too steep.

[soft, enchanting music] So, how have engineers overcome the drop in this sheer valley?

From above, the answer is partially revealed.

A gigantic, looped viaduct.

The train enters a tunnel at one height... ...and exits below, moving in a different direction.

To understand the full picture of this engineering marvel, we have to look deeper.

Hidden from view is a network of curved tunnels dug into the hill.

The tunnels wind around and down like a corkscrew, four times across the valley.

It adds an extra seven kilometers to the journey.

But this detour reduces the gradient by half, making the descent possible.

[dramatic music] [light music] [camera lens clicks] Ahead is the village of Bergun... ...made famous as the backdrop for the silver screen adventures of Heidi.

Written in 1881, the story of an orphaned girl sent to live with her grandfather is one of the world's best-selling children's books, and one of Switzerland's most famous literary characters.

Now at the bottom of the Albula Valley, train driver Carsten Fischer slows to enter this 216-meter tunnel.

He knows that the exit opens out onto over a 65-meter drop.

[Carsten] Now, after the tunnel, we are entering the Landwasser Viaduct.

It curves into a sheer rockface.

[awe-inspiring music] This curved viaduct spans 142 meters, and is constructed from over 23,000 tons of dolomite limestone.

But building this bridge posed a problem.

The gorge below is prone to frequent flooding.

Scaffolding would have easily washed away.

To overcome this, iron frames were cemented into the ravine, and stonework built around them, an innovation at the time.

[music continues] Its daring design and rigorous engineering embodies the Swiss reputation for precision and efficiency.

So much so that the Landwasser Viaduct has stood almost untouched since it opened in 1902.

The tracks ahead, however, are facing an unseen force that is threatening the existing route.

The Glacier Express is nearing the historic village of Brienz/Brinzauls.

Buildings that have stood here since the 12th century are under attack.

Christian Gartmann, spokesperson for the municipality of Albula/Alvra, has witnessed the recent destruction.

Here you have an example of this car port, which is a solid building built of brick and mortar and steel.

You can see how it is literally torn apart.

So, this building will be torn down, because it would be a danger to use it still.

The ground below the village is shifting, in turn causing landslides and gigantic rocks to rain down from above.

And the scale of the problem is enormous.

Imagine the whole village and us standing on a huge surfboard that is about 150 meters deep.

The village is moving at 1.5 meters per year, which is about this far per week.

Up here, we have movements between three and ten meters per year.

Over ten billion cubic meters of rock is sliding down the valley, and straight towards the railway line.

The railway sees deformation constantly, because the mass moves and it moves the whole rail.

At the edge of the village, work is already underway to stop the landslide.

Head geologist Christoph Nanni is overseeing the excavation of a 600-meter-long exploration tunnel.

He believes the village is riding on a layer of soft rock that's filling with water.

The tunnel is being excavated directly under the village, and underneath the sliding mass.

While Christoph works with the hope to create a solution in the long term, pressure is still mounting trackside.

Which is why Marco Sutter and Christian Leutwiler are on the line today.

They're carrying out a monthly check on a system designed to stop the rails being distorted.

Four sets of sliding rails are placed at points along the 1.5 kilometer stretch most at risk from the landslide.

As the ground shifts outwards, these rail sections can slide against each other, lengthening the track.

Marco monitors how much the tracks have extended.

By allowing the rails to expand, the tracks are unlikely to distort, or worse, fracture, so the effect of the landslip is minimized.

[train horn blares] Today, the track doesn't need to be repaired, and the train is safe to pass.

The tracks now run down to the lowest part of the journey.

This is the Domleschg Valley.

Historically a strategic trade route between Italy and Germany... ...it is a valley of castles.

Crowning every hilltop, they protected not only the route, but the fertile orchards and vineyards that supplied the region.

Apples from here were gifted to the tsars of Russia, and its black cherries are a mainstay of traditional Swiss desserts and drinks.

On the Glacier Express, this regional produce is the focus of an a la carte menu.

Head chef Kaila has worked on the train for 27 years.

He caters for up to 280 people at a time, in a kitchen that's less than two meters wide and constantly moving.

With the route celebrated for its tight turns and steep climbs, Kaila has a few tricks to prevent accidents.

Each dish is cooked to order, but storing enough fresh supplies on board to cater for every passenger isn't practical.

So, how can Kaila ensure no one goes hungry?

[whimsical music] Passengers on board the Glacier Express are anticipating an a la carte fine dining experience as they travel through the Swiss Alps.

The galley isn't large enough to store all the raw ingredients Chef Kaila will need to serve everyone on board.

The solution is ingenious.

Utilizing the region's rich abundance of agriculture and trade, along with Swiss expertise in precision timing, Kaila orders ingredients en route.

His shopping list arrives at Chur, the train's next stop and distribution hub, where Hugo Pinto is in charge.

Mission today is that everything is delivered, uh, that we need in the train.

We always order everything fresh, so every day I have to order and look if everything is OK. As the train approaches, Hugo receives updates from on board.

Here we have 41 plates, and now we have 68.

One hour before we deliver, some changes.

Hugo's success relies on meticulous timing, as the train is scheduled to stop for just ten minutes to get supplies.

I've been here six months, and the biggest stress is when, uh, the vegetables, or something fresh, it's not delivered, and I have to take my car and to go and pick it up.

It's not fresh food that's in short supply today.

Hugo has a large order for a local regional liqueur called Roteli.

We only have three bottles, but I need 20.

We have 20 minutes to drive there and take it and deliver it.

With the train's arrival imminent, Hugo must dash across town.

Andrea Ullius's family have made Roteli Liqueur since 1912.

It takes three months to blend, but Andrea has a batch ready to go.

The day is saved!

[chuckles] [lively music] Now we are entering Chur.

[brakes squealing] Working in unison, the team have just minutes to restock the train.

-[man] OK!

-Yeah.

With everything on board, the Glacier Express departs on time... ...and Kaila can continue with service.

As the guests wine and dine, the efficiency and meticulous teamwork of the Glacier Express staff mean they are completely unaware of the logistics needed to put food on their plate today.

Departing Chur, the train line follows the route of the Rhine River.

And suddenly, from above, the terrain dramatically changes.

[enchanting music] Alpine slopes are replaced by rugged cliffs, creating sheer ravines.

Nicknamed the Swiss Grand Canyon, this unique habitat is home to rare alpine orchids and endangered birds.

For the Glacier Express, this almost 13-kilometer narrow ravine has just one passing place.

So the new driver, Mike, must make sure he arrives on time.

From here, it's a direct ascent through the Surselva Valley, to the top of the Oberalp Pass at 2,044 meters.

This is the highest point on the journey.

The route ahead is too steep for a standard engine, so engineers have come up with an innovative solution.

At Disentis, a new engine will be attached for the next section of the track.

Alexi Pally is the train shunter.

Bela, salut!

His job is to oversee the switchover.

From above, another engine can be seen waiting in the wings.

It's eight tons heavier and 20% more powerful.

[beeping] [clanking] It's not just the powerful engine that makes the ascent possible.

Its drive system is fitted with a secret weapon.

At the center of each axle is a cog wheel.

Like the gears of a fine Swiss watch, it's designed to interlock with a tooth track laid on the steep sections of the climb.

Helmut Eyer is the head technician whose job is to check and service the cogwheels.

If the cog is worn, it could damage the tooth rack it rides on.

Inspection complete, this cogwheel is ready for service.

[exhilarating music] Only a fifth of the track from here to Zermatt uses the cog system.

So, at the start of each of these sections, a clever mechanism is used to get the cogs spinning at the right speed to engage the toothed rack.

As the train passes over the transition system, the distance between the teeth decreases, allowing the cogwheel to align perfectly with the rack.

[lively instrumental music] This is the first of the line's systems, so Alexi's job is to make sure the train connects correctly with the rack.

Once the cogs are aligned, the driver can speed up and put the cogwheel into gear.

And Alexi's job is done.

As a result of the cog rail, the Glacier Express can tackle gradients twice as steep as a normal train.

Which is just as well!

The next stop is the Oberalp Pass, a vertical climb of around 900 meters.

[foreboding music] The Glacier Express is nearing the highest and most perilous point on the route from St. Moritz to Zermatt... [dramatic music] ...the climb through the Oberalp Pass, 2,044 meters above sea level.

From above, horizontal lines across the mountain highlight the dangers here.

These are reinforced barriers, an attempt to stop one of nature's most destructive forces... ...avalanches.

On average, they claim the lives of 24 people in Switzerland every year.

Avalanches have destroyed railway lines, bridges, and in recent years, the train itself.

Above the railway, a group is climbing towards an exposed slope.

They are from the Swiss Army.

Today, they're on a mission to assess the potential threat of an avalanche in the area.

Team leader Toni Niffeler is in charge.

The place from the snow profile will measure two meters from one meter 50.

The goal will be to check the different snow layers.

We like to know what time the layer starts to break.

As snow falls, differing conditions form strong and weak layers on the slopes.

Avalanches happen when weaker areas collapse, causing heavier snow above to slide down the mountain.

Today, Toni aims to identify any potential weakness in the snow layers.

First, a depth weight is used to drive a pole into the snowpack.

The force needed to penetrate every centimeter of snow is recorded to assess the density of the layers.

Then, the crystalline structure of the snow ice is measured close up.

[Toni] Now he checks the snow crystals on the plate.

The snow crystal can be different all two days.

They like to change their form.

The structure of the snow crystals reveals where sections may have melted and reformed, creating brittle, unstable sheets and air pockets.

Next, an extended column is dug.

The team tests its stability, applying low pressure at first.

Then harder.

And finally, the weight of a person.

[Toni] OK. Now we have a result.

It's not so good.

It can be dangerous if you have a lot of new snow.

And these tests will mean next three days maybe, with one meter new snow, the avalanche danger can go to big.

Toni's findings raise the avalanche threat level, which means the Glacier Express could be stopped in its tracks if something isn't done.

Across the region, well-laid plans are put into action.

Pilot and operations manager Hansueli Baerfuss is the first to respond.

He works with the railway company to prevent avalanches disrupting the line.

To do his job, he'll need to create an explosion.

Here we have the explosives and we've prepared here.

That's where they mount the explosive cord and igniter.

The explosives are gel-based and water-resistant, making them perfect for working with snow.

Now he secures the cords.

Once that's done, we will put it in the special boxes in the helicopter.

Each detonating cord is cut to 60 centimeters, which gives 80 seconds' burn time from ignition to explosion.

You have to really work very careful with those loads.

You have to be respectful with everything.

Don't make shortcuts, and, uh, just follow the rules.

The explosives are ready and loaded into the helicopter.

Turning.

Temperature rising.

[dramatic music] [propellers whirring] Far above the railway line, Hansueli must make sure that the slopes are clear.

Clear slopes are essential to Hansueli's job, as he plans to start an avalanche... ...by dropping explosive charges into the snow.

In the Swiss Alps, helicopter pilot and operations manager Hansueli Baerfuss is on his way to start an avalanche.

Counterintuitively, starting smaller avalanches reduces the chances of much larger ones forming.

And the bigger the avalanche, the greater the speed and distance it can travel, increasing the risk to the railway below.

The blast from the explosive charges will only have an effect if there is unstable snow at the drop zone.

The challenge is to find the sweet spot.

With the limited supply of charges on board, he has to make each one count, and get as close to the slope as possible.

It takes nerves of steel and experience.

A sudden gust of wind could lead to a catastrophe.

[tense music] On board, the explosive experts use an electronic igniter to set the detonating cord.

[explosion] [dramatic music] A massive, unstable layer breaks free, cascading to form a large, destructive wave of snow and ice.

[dramatic music] But their work isn't over.

There's a vast area above the railway line that needs to be cleared.

[explosion] [dramatic music] [explosion] [music continues] [music fades] [Hansueli] We had a success.

About four huge and big avalanches with a, with a fracture line of, uh, more than three, four hundred meters each, and about, uh, 60, 70 centimeters high.

With the avalanche threat averted, the Glacier Express crosses the Oberalp Pass.

[upbeat music] From Realp, the line enters the longest tunnel on the route, the 15.3-kilometer-long Furka Base Tunnel.

The journey through the heart of the mountain will take over ten minutes.

From above, the Finsteraarhorn, at 4,300 meters, tops the horizon.

Below it... ...glaciers are born.

[dramatic music] These are the largest formations in Western Eurasia.

The greatest of them is the Aletsch Glacier.

It flows for 20 kilometers, and is over 800 meters deep.

The final leg of the journey is through the Matter Valley.

Ahead lies the mighty Matterhorn.

The Matterhorn was one of the last mountains to be conquered in the Alps.

At almost 4,500 meters, the northern face is still considered one of the world's deadliest climbs.

[soft music] Eight hours after leaving St. Moritz, the Glacier Express arrives at its final destination, the spa resort of Zermatt.

Passengers disembark to enjoy the skiing and mountaineering in this breath-taking setting.

The Glacier Express in Switzerland is a railway journey like no other.

From the awe-inspiring beauty of the Swiss Alps, mountain glaciers and rugged canyons, to the spectacular Swiss engineering and innovation making this extreme terrain accessible.

And it's testament to the dedication of the teams who work tirelessly to ensure the Glacier Express is one of the greatest Epic Train Journeys from Above.