d like an eternity. It wasn’t until the 1980s, more than 60 years later, when meaningful action was taken on the metro.
Rather than using a tunnel boring machine like this, it was decided the cut and cut method was the answer. It’s a pretty simple and cost-effective way of creating a shallow tunnel, as seen here with the construction of some of the HS2 tunnels. You dig an excavator trench, then cover it with a strong support system to take the load of whatever’s overhead.
Now, initially, this made a lot of sense since the tunnel was planned to sit just 2 m below the road surface. But this isn’t just any old dig. That 2 m of earth is in the historic city of Thessaloniki. And as you can imagine, there was a lot of concern about preserving artifacts near the top of the soil.
So, the plans were amended and the tunnel was moved down to at least 7 m deep in the city center. But that’s merely the very tip of the arrow to what became the Achilles heel of Thessalaniki’s new metro. But I’ll get back to that shortly. Now, when you’re working on any major project like this, sensitivity over confidential information is crucial.
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Or for password protection, go to proton.me/pass. me/pass/b1mm. You can check out the links down there in the video description or as the pinned comment under this video. But that’s enough about surfing online. Let’s get back to surfing through the streets of Greece. Now, the perfect conditions for constructing an underground rail system include stable and consistent soil layers, limited traffic at street level, and space to work.
But ask any engineer and they’ll tell you it’s rarely that straightforward. Cities build metros because of population increases and travel congestion. However, to build an underground line with entrances on the surface, you first have to close roads and add to the mayhem. It’s kind of one step backwards in order to take a huge leap forwards.
For the year that followed the digging of that first hole in the 1980s, financial problems meant construction kind of dithered. The project faced a lack of support and became a symbol of political failings. That initial tunnel is known as the hole of cavalas and has become a running joke for those in Thessalaniki.
As of 2025, it still exists. 8.5 m wide and 8 m high, supported by air ducts and reinforced concrete. Two long decades then passed in which various attempts were made to fund the metro. There were threats of protest with locals claiming that everything is done in Athens and for Athens. It wasn’t until 2006 when a contract was awarded and work continued once again.
This time at the western end of the new line near the main heavy railway station. By this point, a completion date of 1995 and then 2006 were both missed. A new date of 2012 was agreed, but that was set to be missed too, and delays were taking their toll. For a decade or more, many shops and properties were hidden behind the construction area.
So many people lost money, bankrupt, the customers couldn’t reach their shops and there was an open construction in the heart of uh the city for 18 years. So a whole generation couldn’t see the city center without an open construction in it. The plan for line one, also called the base projects, was to build 13 stations with 60 m center island platforms.
They’d then be fitted with platform edge screens and doors and linked by driverless trains running along a twin ball route measuring 9.6 km. The tunnels were created using two tunnel boring machines with cut and cover used for the stations and the points near the end of the line. Now, with Greece being kind of old, you never quite know what sits below the surface.
It could be soil, soil, and yet more soil. Or it could be the priceless remnants of an ancient civilization. And you can guess what they found on this project. It wasn’t the soil. Over the following near 20 years, this project has been consistently delayed because of historical discoveries. So far, more than 300,000 artifacts dating back over the past thousand years have been uncovered at nine of the station dig sites.
It was found public paths, jewelry, pottery, every sign of city life, houses, shops. It’s a whole city under the city. The discoveries date back to a Roman city center, an ancient road that crossed the area. Explorations were undertaken ahead of each stage of the works, but that wasn’t a smooth process. Archaeologists knew that ancient history would be uncovered.
Those who decided to design the the line to go through Vignatia, I think they ignored the archaeologist. They were not prepared for what they found and they ran in a very important crossroad of the Kumans Maximus and Cardo in Venezuela station. It was the heart of the city back then. A battle ensued to protect Theasaniki’s past and build for its future.
Not everyone loved the idea of moving the relics. There were archaeologists who’d helped uncover the ruins, calling out their treatment. They wanted them kept in place. Some were sliced into pieces to be moved and then stitched back together, leading to questions about their authenticity. It’s worth noting that some people now argue that by carrying out the work and moving these relics, more ancient history has been uncovered that would have remained lost.
Regardless, this work had to progress. The answer was to merge past and present in what the government described as the biggest salvation project in Greek history. Instead of being 7 to 9 m deep, or as initially planned, just 2 m below the surface, the tunnels were dug to a depth of at least 14 m. In some places, they even dropped to 31 m to avoid crashing through buried ruins.
40 years after the hole of Cavaloras was first dug, architects were sent back to the drawing board to redesign the stations. For instance, this station was moved 10 m further east to avoid an ancient Christian cemetery and Bisantine era wall. Major discoveries were made 6 m below the surface at the sites for the Aia Sophia and Venezuel stations dubbed the Bisantine Pompei for their significance and how intact they were.
These sites featured a commercial center of the ancient city with a crossroads built by Caesar Gallerius in the 4th century and reconstructed two centuries later. It delayed construction for years and caused a bitter controversy over what should be done next. The Aia Sophia discoveries were taken apart and moved elsewhere.
However, at Vanazu, the ruins have remained in place and now feature in an open archaeological site. By 2023, the estimated cost of the excavations had soared to nearly $140 million US. The project is way over budget and massively behind schedule, but there’s no denying the final product is a truly Olympian feat. While it might be many years overdue, Line One opened at the end of 2024.
Eventually, it’s hoped that more than 300,000 passengers are going to use the service every day, removing some 60,000 cars from the roads. Now, granted, it feels a bit dog ate my homework to blame the Romans for construction delays in the 21st century, but even Heracus himself would have struggled to meet those deadlines.
To make matters worse, financing issues owing to Greece’s financial crash in the late naughties didn’t help things either. When you walk around the new metro stations today, you’ll feel a real junk position. You jump on rapid driverless trains and then hop off to experience displays of Thessaloniki’s ancient past. It’s a poignant example of what nations like Greece are up against.
They’re so dependent on their rich history, but also face the necessity to build for tomorrow. It costs a lot of money to preserve those artifacts that that lie beneath the earth, but it’s our history. It is an obstacle, but uh it’s up to the scientists to find innovative ways to deal with this problem.
Line two or the Calamaria extension is now under construction, adding another five stations onto the route. It should be finished by late 2025, adding about 5 km of track heading east. By 2040, the plan is to extend east and west with two new metro lines covering 44 stations. Given how long Line One took to complete and the teething problems it’s facing, locals might find themselves thinking, “Here are we go again.
” But Greece is a lot stronger economically than it was 15 years ago. And lessons should have been learned from the early construction challenges along this route. We’ll leave it to Apollo to predict what happens next. What we do know is that Thessalaniki is now home to one of the world’s most impressive metro systems and it’s changing everyday life for its citizens.
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