Fascinating Ways Infrastructure Is Built
Let's explore some fascinating ways megaprojects of infrastructure are built!Technology
Roads, sewage, buildings, electricity and Wi-Fi, these are just some of the ways infrastructure makes the world go round. These structures and systems allow us to live our modern lives to the fullest, and today, we’re going to find out how it all gets made!
Let's soar from skyscrapers to water bridges, running through the most incredible examples of infrastructure around the world, and the fascinating ways they get built!
The Channel Tunnel
While England and France are very different countries, the neighboring nations are just 21 miles apart, the white cliffs of Dover and the beaches of Calais being directly connected by the Channel Tunnel.
While building a safe tunnel or bridge connecting Britain and France was long considered impossible, this began to change in 1866. A civil engineer called Henry Marc Brunel discovered a stable layer of chalk marl running underneath the English Channel. This rocky material has low permeability to water, and generally lacks cavities, making it perfect for tunneling.
Suddenly, the construction of a tunnel underneath the channel became a possibility. However, due to historic tensions between France and England, two world wars, and a lack of funding, plans for the tunnel stagnated. Finally, when the 1980’s rolled around, the French and British governments finalized a joint-plan to construct the tunnel.
If building one underwater wasn’t difficult enough, they decided to build three; the plans requiring workers to build a train tunnel in each direction, with a service tunnel running in between. This triple-tunnel design cost $5.8 billion, and construction began in 1988.
These tunnels were all dug in the same way, with French and British workers using tunnel boring machines to dig towards each other from their respective countries. When used, these 1,100-ton machines are automatically pushed forward using hydraulic cylinders, their giant drills carving through the earth.
They also automatically excavate any soil or rock, transporting it backwards onto a conveyor belt for disposal. What’s more, the boring machines used to dig the Channel tunnel were shielded boring machines, meaning that they were also able to construct the tunnel walls as they moved, installing concrete segments to prevent the tunnel from caving in.
Both the French and British teams used satellite positioning systems to keep track of their coordinates as they tunneled, making sure that their tunnels met up in the middle of the channel with only a 0.7-inch margin for error. The engineers also had to ensure that the tunnels stayed within the layer of Chalk Marl, at times digging as far as 246 feet below sea-level.
After two-and-a-half years of tunneling, the French and British sides of the operation finally connected, French and English workers shaking hands halfway across the seafloor. The big dig was finished but the job wasn’t over. It was time to implement the tunnel’s train tracks and electrical systems, making the infrastructure suitable for travel.
Once all this was installed, the completed tunnel stood at 31 miles long, making it the largest undersea tunnel of all time. Today, this incredible feat of engineering means the journey from Dover to Calais takes just 35 minutes; letting travelers eat breakfast in a Parisian café, and lunch in an English pub, all in the same day.
Submarine Fiber Optic Cables
The internet gives us a world of memes, TikTok dances and online shopping, all delivered through Wi-Fi routers, satellites and a gigantic, undersea network of fiber-optic cables. Indeed, ‘the cloud’ doesn’t always float through the sky, because much of our beloved Wi-Fi is actually provided by 750 thousand miles of cable running underneath the ocean.
When you next try to Netflix and Krill, you could be gulf streaming that season finale from the other side of the world, the longest cable stretching 24,000 miles around the globe, landing in over 33 countries including Germany, India, Australia and China.
These superfast cables, encased in plastic and steel, can transfer data at upwards of 340 Terabytes per second, more than 25 million times faster than the average home internet connection.
These high-speeds are due to the fiber-optic cables’ construction. Thanks to their near-perfect internal reflective properties, these glass or plastic tubes can carry light over extraordinary distances, to sensors at the other end, allowing the transfer of information through ultra-fast flashes corresponding to binary code.
Under controlled conditions, fiber-optic cables have been able to transfer information at 99.7% of the speed of light, which is around 670 million mph. However, the way that these cross-ocean internet cables are installed isn’t quite so speedy.
The cables are spooled out the back of a ship at 6 miles per hour, the boats simply sailing a pre-planned route and dropping the internet down in the waters behind them. As the boats get closer to the shore, they cover the cables in armor plating, ensuring that they don’t get damaged.
Usually, the cables out in the middle of the ocean are safe, pinned in place by their own weight. But occasionally, anchors, hurricanes and earthquakes can damage them, cutting out your Wi-Fi halfway through an episode of your favorite show. Back in 2014, a shark was even captured chewing on one of googles fiber optic wires; talk about a giga-byte.
Moving A Building
In 1929 the Indiana Bell Telephone Company were intending to build a larger headquarters, which usually would’ve involved knocking down one of their older buildings. They soon realized, however, that knocking the building down would cut out the phone service for a huge chunk of their customers.
So, Kurt Vonnegut, the company’s architect and, incidentally, father of the famous writer of the same name, came up with an alternate idea. Instead of tearing the offices down, why not just pick up the 10,000-ton building and move it, giving them space to extend the offices?
Instead of firing the madman on the spot, they followed his advice, using 75-ton hydraulic jacks to seamlessly lift the building ¼ of an inch, before placing hundreds of thin wooden rollers underneath the structure.
Workers were then able to use the hydraulic jacks to push the building at 15 inches an hour, placing new wooden rollers in front of it as it moved.
Astoundingly, the company didn’t just manage to move the building without cutting the phone lines, they also managed to keep the office fully functional. They used flexible materials to lengthen all of the gas, water and sewage pipes, providing continuous service to the offices.
For the Indiana Bell’s employees, it was business as usual, the office workers coming and going during the move, as the views from their desks slowly changed.
After 34 days, the building had been turned 90 degrees, creating a space behind the original building that the architects used to pimp their office, extending the building into a much larger headquarters. Talk about a makeover!
Gate Tower Building
During the 1990’s, one of the world’s strangest ever infrastructure projects took place. It was the Gate Tower Building in Osaka, Japan. A highway curves through the building’s 5th, 6th and 7th floors, and the surreal skyscraper only exists due to a petty argument between Osaka’s government and the landowner.
Back in the 80’s, the area was full of old, deteriorated office buildings, and both the landowner and Osaka’s government had bright ideas to renovate the plot of land. The landowner wanted to build their own skyscraper and the government wanted to build a highway through the area, the plot of land marking the spot of a crucial exit ramp.
The landowner refused to sell the land to the government, and the government refused to alter their plans, triggering the start of a 5-year argument that ended in a truly bizarre piece of architectural compromise. The highway would go through the skyscraper.
The Gate Tower Building satisfied both parties, but building the structure required the use of some pretty innovative construction methods. The building was first constructed up to the 5th floor, where construction stopped to allow a bridge to be built over the top of it.
Once this bridge was lifted into place by cranes, piece by piece, and eventually completed, the rest of the building was constructed around it, sealing it up and turning the road into a tunnel.
Then, piece by concrete piece, with planes of glass and beams of steel, all held together with rivets and bolts, the rest of the skyscraper was constructed like normal, well, except for the road running through the middle, of course. Thanks to this, the elevators run up the outside edges of the building, and floors 5 to 7 contain only stairways and machinery.
You might be thinking that trying to work next to a highway sounds like a nightmare. But the tunnel’s bridge-style supports mean that the road doesn’t actually make any contact with the building, and the walls around the road are filled with a sound-proof casing structure.
This means that the tunnel is effectively sound-proof, and the road doesn’t interfere with the office workers at all. If anything, it just makes their morning commute a little easier.
Venice, The Floating City
Let’s hop on a gondola now, bobbing our way down to Venice, Italy. With its system of canals and bridges, Venice is known as the ‘floating city,’ and for good reason. The city’s islands stand on top of 10 million wooden stilts, driven into the seabed.
The earth beneath Venice’s 120 islands is muddy and waterlogged, terrible for building on. When construction in Venice first started in the 5th century, architects solved this problem by driving millions of 20-foot wooden piles into the Earth, compacting the waterlogged mud together to create a more solid foundation for their city.
Venice still sits on these same wooden piles, and incredibly, instead of rotting or wearing away over the years, they’ve grown stronger. The thick mud below the city is almost completely airtight, which prevents the piles driven into the ground from rotting.
The mud also contains sediment minerals that have naturally been absorbed by the piles, hardening the wood over time. This effect is so notable, that when these logs have been dug up and examined during restoration and construction projects, they’ve been compared to solid stone!
These foundations have allowed Venice to grow into one of the most iconic cities in the world, but these ancient stilts can only hold off the ocean for so long, as the entire city is slowly sinking into the water.
Rising sea-levels, shifting tectonic plates, and structural damage are contributing to the sink, and although Venetians are used to yearly floods during a period called Acqua Alta, these floods are growing more frequent and more damaging.
Some scientists predict that the entire city could be underwater by 2100, so if you want to take a trip to see the floating city’s unique infrastructure, you might have to go before it’s gone-dola.
Ashalim Power Station
This structure below might look like an industrial birthday candle, but it’s actually a renewable power plant, hidden out in the middle of the Negev Desert in Israel.
The Ashalim Power Station contains one large tower, surrounded by tens of thousands of mirrors, dotted around the ground below. These mirrors are called heliostats, panels which automatically track the movement of the sun, redirecting the sunlight to a huge boiler at the top of the 853-foot tower.
Temperatures in this desert region reach up to 118 degrees Fahrenheit, meaning there’s plenty of solar energy to reflect from the heliostats up to the central tower’s ‘thermal solar receiver’.
This receiver features a series of heat-absorbing panels that surround the boiler. Under the desert sun, these panels absorb easily enough heat to boil water inside of the boiler, creating high-pressure steam that turns a turbine, generating electricity.
Unsurprisingly, building this birthday candle wasn’t a piece of cake. The construction company started by mass-producing the mirrors. They created the 50,000 heliostats over three years, before placing them down in the desert, alongside the complex collection of circuitry, gears and motors needed to control their sun-tracking movement.
They then started to build the hollow concrete tower through a process called ‘slip-forming.’ Slip forming involves continuously pouring concrete to create a large, smooth structure with no joints.
As the concrete is poured, workers raise scaffolding and guides around the fast-drying concrete, ensuring that the structure maintains the correct shape, and the concrete pour remains smooth.
Once the silky-smooth tower was built, they had to install the 165-foot boiler, using a system of cables and pullies to lift it all the way to the top of the hollow tower. Once they’d secured it at the top, the birthday candle was finally lit by the mirrors’ reflected heat, fueling 120,000 homes with the power of the star we call our Sun.
Bridging the gap
We know that engineers can dig tunnels under water but what about when we need to cross over rivers and oceans? Building a bridge over a river is a pretty complicated process, with the big question being how to lay foundations in a soggy, muddy body of water. But engineers have a few tricks up their sleeve to get the job done.
For shallow water, often the go-to construction method is batter piles, huge metal rods that are driven into the riverbed with powerful machines called pile-drivers.
The piles are driven in, compacting the mud below them, becoming strong and stable enough to carry huge amounts of weight. These piles act as solid foundations and once they’re spread out across the river, the bridge is built on top of them.
For larger bridges in deeper water, construction of a solid foundation gets a bit more complicated. One method is a Cofferdam, a technique that creates a patch of dry land in the middle of a body of water.
Workers take large metal sheet piles, and drive them deep into the riverbed, creating a watertight enclosure. Several pieces of equipment can be used to achieve this, including cranes fitted with vibratory hammers, which can both pick up a piece of sheet piling, and drive it into the earth.
Once the cofferdam is secure, the crew start to pump out the water inside the enclosed area, creating a dry space that allows the workers to construct the bridge’s foundations, using dry-land building techniques at the bottom of the river.
Once the workers have built the bridge’s towers, they can climb out of the enclosure and flood it with water, leaving behind strong, well-built foundations that will allow them to build the rest of the bridge.
Another method for constructing deep water bridge supports are Caissons. These giant hunks of concrete are typically built on land, before being floated into position and sunk to the bottom of the water.
There are a few different types of caissons, with world-famous structures like the Brooklyn Bridge using pneumatic caissons, used for building bridges on the rockiest, hardest riverbeds.
The pneumatic caisson is sealed at the top, but it has an open bottom-end with sharp-angled edges, meaning that once it’s been sunk, usually using its own weight, the bottom of the box naturally digs itself into the riverbed.
Once it reaches the floor, workers blast pressurized air into a space at the bottom. The pressurized air forces the water out of the space, into the ground below, and the continuous pressure prevents any groundwater from soaking back through the seabed and flooding the caisson.
With an airtight workspace created at the bottom of the river, workers enter the caisson through an airlock, preparing their bodies for the difference in air-pressure, before taking a sealed elevator down to the workspace at the bottom.
They then manually excavate the mud and rock debris from the riverbed, the caisson’s weight causing it to sink further into the ground, while the pressurized air continuing to stop any water flooding in. The workers typically continue digging until the vessel hits bedrock or other hard ground, leaving the caisson on stable footing.
At this point, thanks to prior calculations, the top of the caisson will still be poking out of the water, and once everyone climbs out, all cavities are filled up with concrete. The result is a solid, sturdy foundation for the bridge to be built on.
Those bridge-building techniques often allow cars to travel over bodies of water, but what about boats that need to travel over dry land? As strange as that sounds, that’s where ‘water bridges’ come in.
Navigable aqueducts are bridge structures that allow a canal to run over dry land, letting boats sail straight over valleys, roads and other rivers, instead of having to sail around them. One such construction is the Sart Canal Bridge, a 1,600-foot-long navigable aqueduct in Belgium.
Building this crazy aqueduct was possible through a process called ‘incremental launching,’ a technique often also used for regular bridges. Although footage of the Sart Canal Bridge’s construction wasn’t captured, the timelapse clip below of the ‘Woronora River Bridge’ in Australia shows the process behind incremental launching.
First, they construct the bridge’s foundations, building a series of concrete legs that span across the gap. They then build the top of the bridge in separate pieces, before using hydraulic jacks to shimmy each piece from column to column until it reaches the other side.
After a similar construction process had taken place with the Sart canal bridge in Belgium, it was complete, ready to take on water. The canal bridge connected two parts of Belgium’s canal du-center, and with the bridge lined up and sealed, workers were able to unleash the water, which raced across the aqueduct, establishing a new canal route.
While the Sart Canal bridge is a pretty meaty piece of infrastructure, some water bridges are smaller, but just as impressive to behold. One such water bridge is the Veluwemeer Aqueduct in the Netherlands, which connects two sections of Veluwemeer lake, separated by a manmade road crossing the lake.
Needless to say, constructing the aqueduct without flooding the road was a tricky task. The crew essentially turned the road into one large Cofferdam, extending the artificial embankments further into the water, allowing them to dig out a space for the underground road without flooding it.
Once the dig was complete, they lined the sides of the road with large metal sheets, protecting it from the lake, and the unstable, damp embankments. They then built a short, concrete bridge above the road, before flooding the extended embankments, allowing the lake to run over the water bridge, creating a usable aqueduct, and a totally mind-bending sight when viewed from above!
These canal bridges are a pretty efficient way for a boat to get from A to B, but sometimes, two canals run at such dramatically different heights, that an aqueduct would become more of a water slide than a water bridge.
The Falkirk Wheel in Scotland manages to solve this problem, connecting two separate canals that run 115ft apart.
The structure is a giant Ferris wheel, allowing boats to sail into its two sealed ‘gondolas,’ before moving them 115ft without spilling a drop of water. Once the boats complete their rotational journeys, the gondola’s gate opens, allowing them to sail back out onto the next canal.
Building this highly functional fairground ride took a whole lot of manpower, and the 1,000-person construction crew started by excavating the basin, digging up 8.8 million cubic feet of soil to create a space that connected to the existing Forth and Clyde Canal. They then built the wheel in the basin, the crew using 7,000 cubic meters of concrete and 1,200 tons of steel.
The machine is huge, but the way that it lifts the boats is surprisingly delicate. The wheel is composed of three large gears, one in the center, and one around each gondola. 10 hydraulic motors cause the central gear to spin, and a set of smaller cogs allow the gondolas to smoothly rotate around it, lifting the boats without tilting them.
The trip from the bottom to the top takes around 4 minutes. And, because the structure was meticulously designed for efficiency, each completed cycle reportedly only uses the same amount of energy as boiling 8 electric kettles, according to the company responsible for the Falkirk wheel.
As remarkable as that fact, and indeed the structure as a whole may be, that kettle statistic makes us wonder: are all measurements in Britain related in some way to making cups of tea?
If the 115-foot Falkirk wheel seems impressive, its height pales in comparison to the tallest bridge in the world, the Beipanjiang Bridge in China. This 1,854-foot-tall bridge stands roughly 1-and-a-half times the height of the Empire State Building.
Building the bridge was a tall order, the crew using 44,000 tons of steel to construct its frame. Obviously, using a crane to build a bridge that high in the sky is difficult, so the engineers decided to use innovative new methods to achieve the feat.
They started by building the bridge with tried and tested methods, manually connecting each girder one-by-one. Once the edges of the bridge on both sides of the canyon were complete, the team began connecting girders outward, securing cross-cables for support as they progressed along the huge segments.
At each stage, they used a special crane-attachment to lift the connected girders up, transporting them along the length of the bridge from below. The crane platform would then be extended beyond the end of the bridge, where they could raise each new section to be manually secured by construction workers.
After five years, the spectacular bridge was complete, cutting down the journey across the valley from a 5-hour trek to a 20-minute walk across the highway. Which is great just as long as you don’t look down.
The Beipanjiang bridge was built in just 5 years, which is pretty impressive for a piece of infrastructure of its size. However, when it comes to speedy building, nobody can compete with this next group of workers from the Netherlands, who managed to build a 230-foot road tunnel in 48 hours!
Needing to move fast to minimize traffic disruptions, the Dutch workers started by digging through the road, creating a large gap in the middle of the A12 Highway. Like a TV chef, they then brought in ‘one they made earlier’, using a system of rails to roll a pre-made concrete tunnel into the gap.
Once it was in place, they flawlessly rebuilt the road on top of it, as if nothing had ever happened. By the next day, the asphalt was dried and the road was re-opened to the public, for drivers to pass over, completely unaware of the incredible feat of speedy engineering they were driving over.
If you were amazed at the fascinating ways infrastructure is built, you might want to read this article about the most epic transport operations of all time and this article about the most powerful heavy machines in the world. Thanks for reading!