Steel Sisters, or which machines build Moscow Metro?

Moscow Metro is being build at record-breaking rates. In 2021, Moscow opened its 100th Metro and MCC station — after launching an ambitious Metro development program in 2011.

In order to build new tunnels in record times, they use tunnel boring machines (TBMs), or bores with sweet female names: Lilia, Claudia, Natalia and Marina. Not stopping for a second, those huge steel machines bore and pack the walls of the underground city.

Read about how those machines look, how their names are chosen and who drives them in this article by mos.ru.

Steel team

The inventor of the first tunnel boring machine was Marc Brunel, a British engineer. He saw a shipworm eating away wood leaving a smooth trail behind, and decided to use that method in construction. He was able to turn his idea into a machine in 1817, got a patent secured a year later, and in 1825 the device was already used in construction of a tunnel under the Thames.

In the USSR, a machine like that was first used in 1934 when building the first stations of the Moscow Metro, to break through a span of hard soil between Teatralnaya Square and Lubyanka.

In the time after 2011, 38 tunnel boring machines were used to build various areas of the Moscow Metro; 33 of those were also used at the Big Circle Line (BCL). Right now, six bores are used to drill new radial lines. Marina, Olga, Lyudmila and Svetlana are working on single-track tunnels in the middle of the future Troitskaya Line, Roza and Natalia – at the Solntsevskaya Line extension toward the Vnukovo airport.

Tunnel boring operations at the Big Circle Line, a Russian Metro building mega project, concluded in the end of 2021, ahead of the scheduled time. In different times, the BCL construction used 33 different TBMs; four of them, “four sisters” Nadezhda, Viktoria, Lilia and Pobeda, drilled double-track tunnels. Those boring machines, 10 meters in diameter, are called “giant bores” or “tenners”.

The giant bores drill single enormous tunnels wide enough got two tracks where two trains can run in the opposite directions. Each “tenner” can replace two six-meter bore, while being quicker and requiring less personnel to operate. For example, the average speed of Marina, a six-meter bore, is about 250 running meters a month, while Lilia, a giant bore, covers 350-400 meters in that time.

By the way, Lilia was the first giant bore at the Moscow Metro. They used it to build the Nekrasovskaya Line before transferring it to the BCL. Six meters wide Marina was used to build the Arbatsko-Pokrovskaya, Lyublinsko-Dmitrovskaya, Zamoskvoretskaya, Sokolnicheskaya and Solntsevskaya Metro Lines, and later, the BCL.

Lilia weights over 1,600 tons; its full length is about 70 meters rotor to tail. Six meters TBMs are longer: 80 to 105 meters. Engineers could make the machines shorter by increasing their diameter and stacking equipment tighter inside them: on three levels.

“Using 10 meters TBMs to drill double-track tunnels saves time and manpower. This is the best technology for drilling i.e. underneath water bodies or park areas where certain limitations are imposed on vent shafts placement and tunnel facilities construction,” said Yuri Kravtsov, Mosinzhproect company CEO.

Patronesses of Metro builders

Surprisingly, but save for the Pobeda, almost all tunnel bores have female names. That’s not a coincidence. The tradition originates with St. Barbara, the heavenly patroness of all mine workers and engineers. It’s a global trend: they call the bores after memorable women and even female movie characters.

For example, Roza, a TBM that’s currently used to build a tunnel leading to the Vnukovo Airport, has been named after Roza Shanina, a legend of the Great Patriotic War. She was one of the first female snipers to be awarded the Order of Glory.

The bore drilling the adjacent tunnel supposed to connect Pykhtino and Vnukovo future stations on the Solntsevskaya Line, bears the name of Natalia Kornienko. She’s worked as a train driver at the Sokolnicheskaya Line for over 30 years. Ms. Kornienko was present at the new drilling distance (from Rasskazovka to Novoperedelkino) launch ceremony. A rotor from that bore is now a part of a monument decorating the western lobby of the Rasskazovka station. It’s easily recognizable by its impressive size and bright red color.

The name of the iron veteran of Moscow Metro building is no less pretty: Claudia. She’s been working for the Moscow Metro for some 20 years, drilling about a dozen tunnels at that time: at the Butovskaya, Arbatsko-Pokrovskaya, Zamoskvoretskaya and Lyublinsko-Dmitrovskaya lines. In 2021, Claudia drilled the tunnel between Yakhromskaya and Lianozovo future stations finishing together with two other bores: Tatiana and Irina.

The five six-meters bores delivered from China are famous for their names too. They were all named after the characters of the Papa’s Daughters TV series: Polina, Galina, Maria, Darya and Yevgenia, because the sitcom grew very popular in China as well as in Russia. The five “sisters” were drilling tunnels at the Big Circle and the Troitskaya Line. Recently, Darya and Yevgenia finished drilling at another under construction station, Bachurinskaya.

A 10-meter Pobeda bore was also designed in China. Mosinzhproekt engineers drafted the terms of reference, taking into account the Moscow Metro building experience and the features of the local hydrogeology. Last year, Pobeda drilled a double-track tunnel along the eastern span of the BCL.

Driving a TBM

A modern tunnel boring machine is a verifiable soil processing factory. It looks like so much a giant metal worm: when drilling, it bites into the soil, sucks it in and expels it to the surface. At the same time, tunnel walls are being strengthened with reinforced concrete tunnel rings, 2.5 tons each, which are also being mounted from inside the bore.

Drilling is controlled as follows. A driver, or operator, sits in a special cabin inside the bore, controlling the TBM. Because bores work around the clock, operators replace each other after 12 hours long shifts.

Staff of Mosinzhproekt mechanized drilling department control the operation parameters: drilling rate, refuse soil movement, pressure on the jacks (that make the machine move), rotor rotation power, etc. They also make prompt technical decisions in challenging hydrogeological conditions.

Engineers can do their jobs both from inside the bore and from the drilling control center. The remote control system uses imaging supplied by the TBM’s onboard computer.

Hydraulics technicians, electricians, welders, riggers, pump operators and unskilled laborers all work inside the bore, together with the driver. On average, a bore crew includes 15 people; all of them can be on board at the same time, if need arises. About the same number of staff members work on the surface and in the pit. Strappers, electric fitters, millers and mechanics, along with drivers of the refuse soil carrying wagons, all work to make the drilling machine operate without interruptions.

After the tunnel is ready, construction workers lay the tracks and connect engineering networks. The bores’ average drilling speed is about 10 meters per day, or 300 meters per month.

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