Moscow authorities are very proud of the number and pace of construction of new metro stations. They plan to open six more in the coming year. Work is now being completed at the Troparevo, Rumyantsevo and Salaryevo stations, which will extend the Sokolnicheskaya line to the southwest. They will open either at the end of 2014 or at the beginning of 2015.

Next in line are three stations on the Lyublinsko-Dmitrovskaya line after Maryina Roshcha. According to the city hall's plans, they will be put into operation in 2015. But the builders do not give exact dates. The fact is that, unlike most stations currently under construction, Butyrskaya, Fonvizinskaya and Petrovsko-Razumovskaya will be located deep underground. This method of construction is both more complex and more expensive than shallow construction. The authorities are trying to abandon it where possible. In addition to the stations of the Lyublinsko-Dmitrovskaya line, in the future they plan to open only one deep station - “Nizhnyaya Maslovka” on the Second Ring (TPK). The Village visited the Fonvizinskaya station and learned what “fairytale soil” and “over-talk” are and how the Ukrainian crisis affected the pace of construction.

Photos

Ivan Anisimov

“Fonvizinskaya” will be located a five to ten minute walk from the “Timiryazevskaya” metro station, at the intersection of Ogorodny Proezd, Fonvizin and Milashenkova streets, exactly under the “Ulitsa Milashenkova” monorail station. It will be possible to change from one type of transport to another through a special crossing.

The planned passenger flow during peak hours is seven thousand people per hour. In total, 55 thousand people per day. A transport hub, multifunctional complexes with office centers, multi-level and intercepting parking lots and an elevated pedestrian zone will be built near the station.

The work is carried out by Mosmetrostroy under the control of the single metro construction operator Mosinzhproekt. They began in 2011 with the passage of a mine shaft. This is a capital mining operation with access to the surface. With its help, they make a way to the underground part of the station. Rock, materials and equipment are then raised and lowered along it. Builders also descend to the station along the shaft in a special elevator.

After descending you find yourself in a labyrinth of tunnels. It appeared as a result of excavation work. According to site manager Pavel Kalimullin, they are now 91% complete at Fonvizinskaya. It remains to place 30 rings in the left tunnel (about 22.5 meters) and in the so-called inclined passage. Escalators will be located there. According to the plan, the installation of the rings will be completed by November 15. On average, one ring takes three days to install. To install it, the rock is blasted and then transported on special carts.

Kalimullin claims that the soil at Fonvizinskaya is “like in a fairy tale.” Therefore, the tunneling work was completed in almost a year, which is considered an unprecedented success for this type of station. We are lucky that the limestone here is very strong, there are almost no collapses, and there is little water. But at the second Petrovsko-Razumovskaya station, which is being built next door, water once flooded the station almost knee-deep. Foreman of mining equipment fitters Sergei Tyurin recalled that about 30 years ago, while carrying out blasting work at Polyanka, workers ran into a water lens. This is a small underground lake. There was so much water that people had to be evacuated and almost swim out of the station. The equipment was flooded. Then the problem was eliminated by installing a large diameter pipeline there. Deep pumps pumped out water and spat it out into the Moscow River.

Tunneling work is the first stage of construction. The second is waterproofing. Waterproofing consists of three parts: embossing, pressure control and rebolting. Now in some areas this process is underway - replacing bolts. First, install rigid metal washers to prevent deformation. And then they change them to asbestos-bitumen ones, which do not allow water to pass through. Now the bottom of the station is almost completely in water. It will be pumped out, and after waterproofing work is carried out, it will stop getting there.

At Fonvizinskaya, waterproofing is already underway, but not very actively yet. The work manager complained to The Village that by New Year he needed to recruit 150 minters to work in all sections of the station at once.

At the same time, the openings are being opened. Now the construction site is divided into three parts - right, middle and left stations. The middle one is where the platform will be located. Right and left are the place of future paths. At the station their diameter is 8.5 meters, in the stages - 5.49. Openings will be located between them so that passengers can get from the platform to the trains.

The third stage of construction after waterproofing is the construction of main structures. This includes finishing the station, laying tracks, installing escalators - everything that will bring the station into the form familiar to passengers.

But something will remain behind the scenes. For example, a block of technical premises. It runs parallel to one of the tunnels for 150 meters. There is the heart of the station - transformers, substations and everything that is necessary for its functioning.

Cast iron tubes, almost the main element for subway construction, are also not visible to passengers. They fence off the station from the ground, and they are responsible for the absence of deformations. Tubings are produced in Dnepropetrovsk. When the crisis began in Ukraine, construction stopped for 15-20 days due to delays in supplies. Now the pace has been restored. Therefore, according to Pavel Kalimullin, Fonvizinskaya will most likely be completed in 2015. Unless, of course, the unpredictable underground bowels present some surprise. This is what it should look like:

The Lily shield works for two people - it builds a tunnel for two paths at once. This machine is both larger and faster than its “sisters”, which also have female names: “Almira”, “Olga”, “Svetlana”, “Victoria”, “Anastasia”... Modern technology, of course, is no match for the pick and shovel, with which the first Moscow subway stations were built in the 1930s.

Her weight exceeds 1600 tons, her waist circumference is more than 10 meters, and her height is 66 meters. This giant “lady” bears the name Lily, which is more reminiscent of a flower or a fragile woman, but not of an iron machine. "Lily" is building tunnels for the metro. One such mechanized tunnel boring complex, or shield, as the builders call it, can replace two six-meter ones. On the eve of 2017, Liliya began digging a tunnel between the Kosino and Yugo-Vostochnaya stations.

Metro construction workers consider this event significant. The complex is unique for Moscow: it surpasses others not only in size, but also in skills. “Lily” is laying a path along which two trains will go in different directions at once. Its main advantage is speed. If a standard six-meter shield covers about 250 linear meters per month, then “Lily” - 350-400.

Powerful cars with fragile names

Traditionally, tunnel boring machines are given female names. This custom appeared with the light hand of Richard Lovat, the founder of the world famous company LOVAT. He decided that his company's shields would bear women's names in honor of the patron saint of underground mining. Barbara. And today the hard men’s work in the metro is performed by “Alana”, “Natalia”, “Claudia”, “Olga”, “Eva”, “Svetlana”, “Victoria”, “Polina” and other “ladies”.

On average the distance betweenstations - 2-2.5 kilometers. The train passes them in three minutes, and the tunnel boring complex overcomes 12 meters in 24 hours. Walking 350 meters per month during tunnel construction is a good indicator. Despite the difficult geological conditions, some “ladies” cope faster. For example, “Tatyana” traveled more than 2.8 kilometers, connecting the “Ochakovo” and “Michurinsky Prospekt” stations with a right-hand running tunnel.

Navigation electronics and rest room in the iron worm

The panel is brought to the construction site in parts and assembled on site in a special pit, which builders call an installation chamber. Its size is no smaller than a football field - 60 by 70 meters. It will be the beginning of a new tunnel. The car will end its journey in the same chamber, but with a different name - dismantling. There it will be dismantled and taken away for the construction of a new tunnel.

The length of the worm-like shield can reach 100 meters. The head part is the cutting mechanism called the rotor. It has special incisors. They literally bite into the rock, paving the way. Immediately behind the rotor is a drive that runs the cutting mechanism.

The shield must have a closed container for cement mortar that fills the voids between the tubing and the soil. And also - a caisson chamber, jacks, an operator's cabin of a tunneling complex and even a rest room for builders. The latter is also not superfluous, because work goes on around the clock. Workers work in three shifts; One panel is serviced by about 30 people per day.

The complex paves the way using highly accurate navigation electronics. The shield operator constantly checks the coordinates of the route, because the tunneling complex can deviate from the specified parameters by no more than eight millimeters. A schedule is drawn up for each mechanism to know where it finishes excavation and when it moves on to the next stage.

The future space of the tunnel is formed by tubings - concrete blocks. When it is ready, the builders lay the rails and connect the utilities. Where is the soil put? It goes into special pockets of the shield, from there along a conveyor into trolleys running on temporary rails, and then to the surface. Trolleys transport the soil and supply the necessary parts, such as tubing. The soil does not remain at the construction site for long; it is sent to special landfills. One shield requires 30 trucks per day to remove soil.

Non-standard approach: extended shield and tunnel for an escalator

Sometimes metro builders have to improvise. The reason is most often the lack of free sites for construction. For example, in Moscow City, when they were building the Delovoy Tsentr station on the yellow line, the car was installed on an area no larger than a school gym. The shield had to be built up underground, lowering ring after ring.

And at the Petrovsky Park site there was very little time to assemble the mechanism. Usually it takes a month or two to install the shield, and in order to assemble it faster, the head part, weighing about 150 tons, was not disassembled, but was lowered entirely to a depth of 28 meters. To do this, a 450-500-ton crane was installed on the edge of the pit. Experts carried out many calculations to make sure that it would not collapse the foundation pit.

Moscow builders also have their own inventions. They were the first in the world to build tunnels under escalators using shields. The know-how was applied at the Maryina Roshcha station on the light green line. This practice has not spread abroad, because in Europe stations are mostly built at shallow depths and tunnels for escalators are dug manually.

The secret of double-track tunnels

The Lily giant is needed to build double-track tunnels. The trains in them travel towards each other. If at a regular station the rails stretch on both sides of one platform, then at the new tracks in two directions they will run in the middle of the hall, and two platforms will be located on the sides. That's why they are called double-track.

Such shield tunnels pass more slowly than ordinary ones with a six-meter diameter. Why are they being built? Firstly, the excavation period is still shorter, because they are building one tunnel instead of two. Secondly, this technology reduces costs.

Such tunnels will be built in Moscow in three years. Two double-track sections will appear on the Kozhukhovskaya metro line and two more on the Third Interchange Circuit, in the north and east of Moscow. This method is used all over the world. For example, in Madrid, 90 percent of all tunnels are built this way. By the way, the technology itself is called Spanish.

How a worm helped invent the tunnel walking machine

According to legend, the English engineer Mark Brunel created a machine for laying tunnels, taking a closer look at the ship worm. Its head is covered with a hard shell, with the help of which the worm drills into the tree and leaves a layer of lime on the walls of the passage.

Russian Emperor Alexander I asked the inventor to design a tunnel under the Neva and build it using such a machine, but the plans did not come true. The Emperor decided to build a bridge in the designated place, and the shield for the first time built a tunnel not in St. Petersburg, but in London.

Moscow records

At first, the Moscow metro builders had only eight horses and one truck in their arsenal; even shovels had to be taken from the street cleaners. For the first time in Moscow, a tunneling shield went underground in 1933-1934, when the section between Lubyanka and Teatralnaya Square was being built. Under its protection, building tunnels at depth has become not only easier, but also safer. American engineer George Morgan, who advised the builders, warned that the shield could not travel more than 75 centimeters per day. But Moscow workers set a record: they managed to increase their speed and walk more than 4.5 meters in 24 hours.

Today machines work tens of times faster. The tunnels are laid by ultra-modern German shields Herrenknecht, Canadian LOVAT and American Robbins. By the way, the new “Lily”, which took almost a year to create, is also German, as are “Anastasia” and “Almira”. She was brought from Germany in April.

Metro construction stages:

Choosing a location

First of all, the metro is being laid in remote areas of the capital. This takes into account how many people live there and how much housing will be built in the future, as well as whether there are industrial enterprises, business clusters and large office centers in the area where people come to work every day. The choice of location for a new station is also influenced by such factors as the population of neighboring areas and even the Moscow region. Often they decide to build a station where vehicle traffic is densest.

Engineering surveys

At this stage, the information necessary for the further development of the feasibility study of the project and working documentation for construction is collected. Engineering surveys for metro construction should include geological, geodetic, environmental and other types of surveys as necessary.

Design

At this stage, the depth, types of structures and method of digging underground tunnels are determined, and design and estimate documentation is drawn up. Simply put, designers determine the optimal “route” of the underground road and the location of the station.

The project is being prepared in such a way that construction does not damage architectural monuments, buildings on the surface, parks and public gardens, and at the same time costs the budget as little as possible. If the tunnel route passes close to existing facilities, then, if necessary, methods of engineering protection of these structures from noise, vibrations and stray currents that arise during the construction and operation of metro lines are developed.

Construction

What objects are located on the surface mainly determines how deep the new station will go. Under street highways, the metro can “hide” at a very shallow depth - less than 20 meters. This is the most economical option and is chosen for most new stations. If there are residential buildings on top, then you will have to “go down” deeper.

There is a closed method of construction, without opening the surface, and an open method, in which tunnels and stations are built, respectively, in dug trenches and pits and then covered with soil.

The closed method is used in the construction of deep lines; shallow stations are built mainly by the open method.

The construction of a “deep” metro begins with the laying of a mine shaft for a cage (elevator), which will deliver metro construction workers and the necessary equipment “to the workplace.” The platform that breaks out around the trunk can be compared to a huge staircase. This is where the tunneling begins. On the same stand, after drilling, tens of tons of soil are transported to the surface every day.

The deeper the station, the more expensive it is and the more resources it requires. In 2011, in Moscow, it was decided to build the majority of new stations using open-pit methods. It is enough to dig a pit, install concrete structures, backfill and lay tracks inside the resulting corridor. This is not only cheaper, but also much faster than building deep stations.

Drilling and strengthening of tunnels is carried out using cast iron tubing or waterproof reinforced concrete lining blocks.

Installation of escalators

In parallel with the construction of the tunnel, the station itself and the transition system are being built, then communications are laid in the metro and escalators are installed.

At deep metro stations, escalators are installed in long inclined tunnels - exits. The large length of such escalators imposes special requirements on the strength of their structure and the reliability of the brakes.

For shallow installations, floor escalators are used. What is important is that all new stations are also equipped with elevators for people with disabilities.

Interior design

The capital's metro is rightfully considered the most beautiful in the world. In most countries, stations are utilitarian and indistinguishable from one another. Despite the fact that Moscow Metro stations are now built according to standard designs, each of them has its own special architectural and design solution.

Design projects for Moscow metro stations under construction can be viewed.

Typical projects:

For shallow stations, three main types are used:

• vaulted station, with an open, column-free platform;
• two-span with columns in the middle of the platform (for shallow stations);
• three-span (for shallow stations).

In the center of Moscow, due to the density of historical buildings, the old type of deep stations of two types is used - column and pylon.

Technologies to help metro builders

Tunnel boring complexes

In the 30s, the first Moscow metro stations were built by hand: with a pick and shovel. Today, metro builders have advanced technologies in their arsenal. To lay subway tunnels, a fully automated, heavy-duty structure called a “boring shield” is used. It can probably be compared to a “steel worm” that drills a path through the rock, leaving behind a finished tunnel.

According to legend, the inventor of the world’s first “mining shield,” the Englishman Mark Brunel, actually came up with such a design after he took a closer look at the “work” of an ordinary ship worm when he served in the navy. He noticed that the mollusk's head was covered with a hard shell, with the help of the jagged edges of which the worm drilled into the tree, leaving behind a smooth protective layer of lime on the walls of the passage.

The idea of ​​a machine that greatly simplified the construction of tunnels took shape in 1817, when Russian Emperor Alexander I asked Brunel to design a tunnel under the Neva in St. Petersburg. True, the engineer was never able to work in Russia - the emperor ultimately decided to build a bridge in the intended location.

Nevertheless, in 1818 Brunel's first shield was patented, and in 1825, with its help, construction of a tunnel under the Thames began.

In the first machine, the soil was selected by 36 miners at once, each located in his own cell. After excavating the soil a few centimeters, the shield was moved slightly forward. This was not an easy job, given the constant seepage of water (the river bottom was located only a few meters above the arches of this double tunnel). Several floods in the mine claimed the lives of seven workers, and on one occasion Brunel's son nearly died. Moreover, swamp gas has flared up more than once at an underground construction site. And yet the work ended in triumph.

On the first day after the opening of the amazing structure, 15 thousand people passed through the tunnel. Since then, Great Britain has been deservedly considered the pioneer of shield tunneling, and the shield method itself has been called “London” in the specialized literature.

In our country, a tunneling shield was first used in metro construction in 1934 to excavate a difficult section of the first stage of the Moscow metro between Teatralnaya Square and Lubyanka. And during the construction of the second stage of the Moscow metro, 42 shields were already working simultaneously on the routes - a record for the volume of equipment used. Since then, more than 70% of the capital's metro tunnels have been built using this technology.

On the first panels, as already noted, the soil was manually selected by workers using a jackhammer and removed through an already built tunnel on trolleys. To move the shield forward, screw jacks were used, which rested on the finished section of the tunnel lining and pushed the machine forward.

The size of the tunnels grew, and the design of the “worm” also improved: horizontal platforms appeared in its front part, which allowed workers to develop soil simultaneously from two (and sometimes more) tiers. However, due to the large amount of manual labor and frequent accidents, the penetration rate left much to be desired.

The process was significantly accelerated by the use of prefabricated lining from large elements - initially cast iron tubing. The giant rings that form the tunnels began to be assembled from several elements.

The next stage in the “evolution” of tunnel boring complexes was the development of structures with the so-called “soil load”. When operating such a shield, the rock is first fed into a sealed chamber, from which the soil is removed using the “meat grinder” principle using a screw conveyor.

Today, tunnels are built in the most difficult engineering and geological conditions, and modern shields are designed for tunneling in various soils, including unstable ones. The complexes operate in two cycles: first they develop the soil, then they build the lining, installing the blocks. The average speed of penetration of shields today is 250 - 300 m per month, the average cost is 13 - 15 million euros.

Moscow builders were the first in the world to build inclined tunnels for escalator areas using tunnel-boring shields. By order of Mosmetrostroy, the Canadian company Lovat developed and manufactured a tunnel-boring complex with an outer diameter of 11 m. It was with its use that the capital's metro builders for the first time carried out shield tunneling for escalators. This happened at the Maryina Roshcha station on the Lyublinsko-Dmitrovskaya metro line.

By the way, the everyday life of metro builders is not at all devoid of romance: once Richard Lovat, the founder of the world-famous manufacturer of tunnel-boring shields LOVAT, decided that all the complexes produced by his company would bear women's names in honor of the patroness of underground work, St. Barbara. With his light hand, a tradition was born - assigning women's names to shields. That is why in Moscow there are machines with the names “Claudia”, “Katyusha”, “Polina” and “Olga”.

Solving Geological Problems

The most insidious enemy of underground mine workers is quicksand: masses of almost dusty sand mixed with 10 - 15% clay, like a sponge soaked in water.

Back in the 30s of the last century, when the first metro was being built in the capital, metro builders were faced with very difficult hydrogeological conditions. At the same time, a system was used against soil collapse and other typical problems that threaten tunnels, which to this day is considered one of the most thoughtful and reliable. We are talking about soil freezing, based on a simple but effective system.

There are several methods of freezing, the oldest of which is the so-called “brine”.

It consists in the fact that the work site is fenced off from the general mass of aquiferous soil by a wall of permafrost. Frozen soil a meter or two thick at a temperature of -12 degrees can practically withstand any rock pressure and perfectly resist the penetration of groundwater. How to make the cold go underground? This is achieved with the help of artificial devices from special refrigeration machines.

The refrigeration machine is based on the fact that the refrigerant (liquid ammonia, freon, etc.), which is released from tanks into prepared freezing columns, takes away heat from the environment when it evaporates. Its vapors are liquefied again using a compressor and condenser, and the cold formed in the evaporator is used to cool the non-freezing working brine of calcium chloride. The brine at a temperature of -25 degrees enters the cooling system. To install it, wells with a diameter of 150 - 200 millimeters are drilled along the excavation contour at a distance of one meter from each other. Freezing columns consisting of double pipes are lowered into the wells. The freezing brine enters through the middle pipe, and through the outer pipe, after natural heating in the ground, it returns to the refrigeration machine. Thus, the circulation of brine occurs continuously.

After about a month of operation of the refrigeration machine, the soil around the individual freezing columns freezes into a monolithic mass, protecting the mine site from penetration of groundwater and crumbling of the walls. Now the refrigeration machine must only support the ring of permafrost until its walls are excavated and secured.

A more modern method is low-temperature freezing using liquid nitrogen.. It is a colorless liquid, the evaporation temperature of which is very low (at atmospheric pressure it is -195.8 o C).

Liquid nitrogen is produced at special plants by liquefying atmospheric air at low temperatures and then separating it into liquid nitrogen and oxygen, which have different evaporation temperatures. Liquid nitrogen is transported in special containers (tanks).

Unlike other industrial refrigerants (ammonia, freon), which can only be used in a closed refrigeration system, liquid nitrogen is used once (the evaporating gas is released into the environment).

The method of low-temperature freezing using liquid nitrogen has a number of advantages compared to conventional (brine) freezing. When freezing with liquid nitrogen, freezing stations and pipeline networks are not needed. Liquid nitrogen delivered to the construction site from the tanks is released directly into the freezing columns. The freezing rate increases, which is especially important at high rates of groundwater filtration, as well as with the influx of thermal and mineralized waters. To freeze 1 m 3 of soil with a water content of up to 30%, 1000 liters of liquid nitrogen are consumed. Liquid nitrogen is explosion- and fire-proof and non-toxic.

However, both of these methods have recently been used quite rarely. Liquid nitrogen is unreasonably expensive, and it takes more than a month to “set” the soil. Therefore, freezing today is used only when excavating inclined escalator tunnels.

For other cases, there is a more advanced and quite economical alternative - the technology of jet grouting of soils, or jet grouting. This is a method of soil consolidation, based on the simultaneous destruction and mixing of soil with a high-pressure jet of cement mortar. As a result of jet cementation of the soil, cylindrical columns with a diameter of 600 - 2000 mm are formed in it.

The technology appeared almost simultaneously in three countries - Japan, Italy, England. The engineering idea turned out to be so fruitful that over the past decade it has instantly spread throughout the world.

The essence of the technology is to use the energy of a high-pressure jet of cement mortar to destroy and simultaneously mix soil with cement mortar in mix-in-place mode (mixing in place). As a result, piles are formed in the soil mass from a new material - soil concrete - with sufficiently high load-bearing and anti-seepage characteristics.

The construction of soil concrete piles is carried out in two stages: direct (drilling a well) and reverse movement of the drill string. During the reverse stroke, the column is lifted while simultaneously rotating.

With the help of jet grouting, a very durable pit is obtained and reliable foundations are built for any structure. A pile field is created in a checkerboard pattern, one pile overlaps another, and the result is a monolith - a rock. And you can build anything on it. This technology is especially effective when it is necessary to build objects in sandy soil, soft clay or other soft soils.

Thanks to these technologies, today metro builders can work in the most difficult geological conditions, building tunnels that lead the metro to new areas of the capital.

« Precious » tools

Metro construction could not do without nanotechnology. Today, builders can use innovative tools - diamond working drills, cutters and tips.

Initially, this know-how was used for drilling reinforced concrete and other building materials and turned out to be so convenient that it began to be used for complex mining work in rocky soil. It significantly increases the level of work safety and the speed of penetration - construction is literally accelerated several times. It is interesting that the cost of “diamond” equipment is not much higher than usual - the difference in price is only 10 - 15%.

Traditional legacy tools are unable to provide as many technological benefits. Thus, a diamond drill can make holes in any plane and at any angle; using the contour method, you can obtain regular rectangular holes of any desired size, which results in an ideal contour. “Precious” tools allow you to work in the narrowest and cramped spaces; they can handle materials of any hardness. What is important is that the method is silent and environmentally friendly.

Bodies of water have always presented problems for engineers. At first, rivers were powerful facilitators of trade. But sooner or later, people needed to get to the other side.

Boats such as ferries were the earliest and most obvious solution. Eventually, engineers began building bridges. Soon, however, there were people who wanted to make tunnels for reservoirs. Apart from hiring a crack team of moles and beavers, how could this be done?

Workers opened the gates one at a time to dig through several centimeters of dirt. Once a little progress has been made, the entire shield will be pushed forward. Behind it they build a thick brick wall that will become the shell of the tunnel.

This was of course very labor-intensive work. For example, it took his workers nine years (from 1825 to 1843) to build a 365-meter-long tunnel under the Thames River in London. It became the first underwater tunnel in the world.

Technology has come a long way since Brunel's time. Today, underwater tunnels are created by huge tunnel-boring machines. These machines cost millions of dollars, but they can create large tunnels in a very short time.

The round plate with disc cutters rotates to cut through the rock, centimeter by centimeter, slowly and steadily. When the machine digs a tunnel, it helps strengthen the walls, which ultimately support the tunnel.

France and England used 11 massive tunnel boring machines to create, in just three record years, the three tubes that make up the 51-kilometer Channel Tunnel. The tunnel is called the Euro Tunnel or the Channel Tunnel. These tunnels now connect the two countries underwater.

Another new method for creating underwater tunnels is the trench method. To use this method, builders dig a trench in a river or ocean bed. Then they sink the finished steel or reinforced concrete pipes into the trench. After the pipes are covered with a thick layer of rock, workers connect the pipe sections and pump out the remaining water.

This method was used to create the Ted Williams Tunnel, which connects the south side of Boston to Logan Airport. 12 giant steel pipes that were sunk in the trench were each 100 meters long and contained a completely finished infrastructure!

Engineers are always coming up with new ideas. Based on experimental rock-cutting techniques, tomorrow's underwater tunnels could be built using high-pressure water jets, lasers or ultrasonic machines.

New technologies can help build tunnels that once seemed impossible. For example, some engineers would like to build the Transatlantic Tunnel to connect New York with London. The 4,960-kilometer tunnel could accommodate a train that could travel at speeds of 8,000 kilometers per hour. A journey that now takes 7 hours by plane could someday take less than one hour!