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Cross, South London. Extensive tests and measurements will be made to check the progress of the experiment and determine the value of bentonite in tunneling.

Medical advisers to tunneling professions are also interested in this application as if successful it could start a trend away from the use of compressed air and its associated risk particularly bone necrosis.

II. Make up questions from the words and answer them.

1.Contract / what / experiment / Research / was / by / the / National / Development / Corporation / backed?

2.What / will / tested / machine / be?

3.What / involved / in / be / test / will?

4.How / will / the / valid / contract / be / long?

5.Why / in / interested / are / medical / application / advisers / of / the?

III. Imagine that you were a participant of the experiment described. Write a report saying about the results.

Home Exercises

I.Complete the word-building table.

II. Do the puzzle and you will find out what words are written on the wall of one of London Underground stations.

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Text 38 

III. Is it convenient to travel by underground? Why do you think so? Read the text and add some ideas to your answer.

GENERAL IDEA OF THE UNDERGROUND

In metropolitan areas and in regional urban areas it is difficult to ensure the basic function of roads – i.e. safe and smoothly flowing traffic – because of traffic congestion and frequent daily traffic accidents. Users want safer, more convenient and higher-quality traffic services that meet their needs better. It is evident that underground being an urban non-street railway system can solve the problems of carrying passengers, as well as the problems of traffic jams, air contamination and noise. The underground railway is the quickest, safest, most reliable and comfortable means of travel which can be found in 80 cities all over the world. Twenty-eight countries can afford these metropolitan traffic facilities not only in their capitals.

But from the technical point of view the underground railway system is very expensive and complicated constructional works providing much higher traffic efficiency than ordinary roads. In addition local train services and high-speed tram links which look like the underground railway system complement the highly developed public transport network. The underground railway system differs from the high-speed tram in the track, the overall dimensions of the rolling stock and the method of tapping off the current.

The underground railway system incorporates subsurface lines, ground based lines and elevated lines located on trestle bridges.

The underground railway carrying capacity depends on the number of

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coaches which ranges from two to eight per train, the seating capacity which ranges from 90 to 270 passengers per coach and the frequency of train running. The time intervals range from 90 seconds to six minutes.

The underground railway systems all over the world use two types of line intersections. Some foreign subways use one-level lines. The passengers can get to their destination or other stations using one line without changing trains. The underground railway lines in Russia are laid in different levels. This type of lines offers absolutely safe service from any possibility of the train collision. To allow passengers to change from one train to another, underpasses are provided at various underground stations.

The expected growth in the use of all possible means of public transport will cause chronic traffic congestion at the bottlenecks and noise will exceed the requested limit. In considering these concerns the underground railway has no alternative. In addition to its other beneficial effects it provides the environment quality standard.

IV. What notions are defined below?

-railway engine with several carriages or trucks linked to or pulled by it;

-a crowded mass of vehicles that makes movement difficult or impossible;

-the solid surface of the earth;

-an instant of one object striking against another violently;

-a place where trains stop on a railway line

V. Read the text and correct the following sentences:

1.The London Metro is the longest one.

2.The length of the Budapest Metro comes third after London and New York.

3.The first underground railway lines were laid in 1868.

4.Paris has the shortest metro in the world.

5.The Metro in Moscow was being built during four long years.

The earliest underground railway lines were erected in London in 1863. The idea was proposed by Charles Pearson in 1843. According to his project almost all lines were to be laid close to the ground surface. The London Metro has come to be called the Tube. Its length is about 400 kilometers but it is not the longest one.

New York was the second city to build the subway. The first track was laid in 1868 and nowadays its length ranks next to nothing. The USA subway currently heads the list of the underground railway systems because eleven cities in US involve subway into public traffic and its overall length is 1060 km.

Budapest built its underground in 1896 and occupies the third place in the history of the metro construction.

The length of the Paris underground is about 200 km and it comes third after

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London and New York.

The shortest metro line was built in Turkey. Its length is only 600 m but Istanbul is very proud of the metropolitan means of traffic.

In June 1931 it was decided to start the building of the Metro in Moscow. It was put into operation on May 15, 1935. It was called the record period of time by the world press. The Metro was erected in accordance with the Moscow Master Development Plan but since then building work has not stopped for a single day. The surface buildings and underground halls of the Metro stations are spacious, well lit and ventilation facilities are essential. They are equipped with fans, dust collectors and mufflers. The metro stations are decorated with marble, bronze, aluminum and glass. The cleanliness of the Moscow Metro has been commented on by all users. “No smoking” became a hard and fast rule on the very first day of its existence. All the deep stations have escalators. The train speed is 70 – 90 k/ph.

New metro lines are being constructed all over the Russian Federation and six Russian cities have already afforded the underground.

VI. Find one meaningless word and change it. Give the main idea of the text.

The underground design in Rome was proposed in 1881 but the erection of the Metropolitan began only after the World War II in 1946 and its ten stations were put into operation in 1955. The builders found ancient ruins and antique statues while digging the puttles. Many of these statues and mosaics were well preserved and at present they decorate the concourses of the Termini – main railway station in Rome. All these marble gods and goddesses remember the ancient Roman carriages and nowadays watch hi-tech means of transport.

The spacious halls of the underground stations were most reliable refuges for people in many cities during the World War II. Besides, many ancient books and rare collections from the museums spent the war in the underground puttles. The underground railways were prepared for any emergency situations. In London some of the unused Tube puttles five miles in length were occupied by an airplane producing plant.

VII. Look through the information above (Ex. III, V, and VI) and complete the following sentences.

1.Underground can solve the problems of…

2.The underground railway is the … means of travel.

3.The underground railway system differs from the high-speed tram in…

4.The earliest underground railway lines were constructed…

5.The overall length of the American underground railway systems is…

6.The Metro in Moscow can be described as…

7.The Roman underground is decorated with…

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Home Exercises

I.Memorize the words from Ex. I page 139.

II. Write an article comparing automobile roads and underground.

Text 39 

I. Listen and repeat:

II. Scan the text for about 10 minutes. For questions 1 – 4, choose the answer (A, B, C, D) you think fits best according to the text.

1. The underground railway tracks are laid on…

A)crushed rock.

B)gravel.

C)concrete base.

D)sand.

2.The sleepers of the railroad track are … long. A) about three meters

B) about two meters

C) about a meter and a half D) about one meter

3.The lining in main line tunnels is made of the … parts. A) reinforced concrete

B) cement concrete C) concrete

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D) cement

4. Passengers can change levels using…

A)lobbies.

B)power-driven stations.

C)moving stairways.

D)pull chambers.

III. Read the text and check your answers.

THE UNDERGROUND RAILWAY SYSTEM STRUCTURES

The track construction of the Underground Railway System differs from the usual railway track. The sleepers of the railroad track rest upon a bed of crushed rock or gravel, which is called ballast. The tracks of the underground railway are laid directly on concrete base. The main idea of using concrete in this case is to keep air free from dust but it involves heavy outlays. Were the track imbedded in foundation materials i.e. slag, gravel, ash, sand, hard earth or even broken stone, the trains would be followed by the dust clouds.

The ties or sleepers in the metro are shorter than those of the railroad track, which are 2,7m long. The metro sleepers are only 0,9 m long. They are separated by a chute. The contact rail is laid along the whole track and arranged to carry high voltage current of 825 volts. It is attached to the brackets and transmits the direct current to the train electromotor through the pantograph.

The underground railway subsurface and oversurface structures involve stations, main line tunnels, lobbies, tunnels for moving stairways and escalators, underpasses, ventilation and sanitary engineering as well as a power supply system.

The main unit of any underground railway system is a main line or running tunnel. All running tunnels may be subdivided into single-lane one-way tunnels, double-lane and four-lane tunnels. The New York Underground has two usual lanes and two high-speed lanes called «expressway». The lining in main line tunnels is of circular shape. As a rule, it is erected of the reinforced concrete segments or cast iron liners, i.e. it is assembled from separate units. Crossover tracks can divert the trains from one track to another. The trains may be inspected and repaired at the dead-ends.

Needless to say the stations represent one of the main parts of the underground railway system to provide the wide choice of services for passengers. Attractively designed underground structures represent a continuation of the above-ground architecture. The stream of passengers can move freely through entrances and exits of the aboveground and underground lobbies using special staircases linking the underground areas with the over surface streets. After a while, passengers no longer notice whether they are moving above or below

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ground because the structural layout itself as well as the different functions offered within the space, extend the main «room of action» and also create the atmosphere of «city within the city». Underground stations are regarded as most efficient because they provide the spacious lobbies and leave the city areas for other public needs. One underground station may have up to nine entrances and exits. The height difference inside the underground lobbies is almost completely canceled out by the structural arrangements. The width of some underground passages ranges between two and six meters, their height cannot be less than 2,5 m. The passengers can move from one station concourse to another or from one entrance – exit lobby to another one walking along these underpasses. In addition, escalators and stairways are provided to allow passengers to change levels.

An escalation complex involves an inclined stairways tunnel for the three stairways within it, a power-driven station to move the staircases and a pull chamber. As a rule, this tunnel’s diameter is 8,1m. The escalators of Russian production provide the lifting of the passengers up to 65 m.

IV. Match the English and the Russian equivalents. Use the English words in the sentences of your own.

V. Mark these sentences true, false or not given.

1._______ There is no difference between the usual railway and underground railway tracks.

2._______ When the underground railway tracks are imbedded in ash, the trains are followed by the dust clouds.

3._______ The sleepers of the railroad track are separated by a chute.

4._______ The dimensions of the metro station are influenced by the number of passengers to be carried.

5._______ Any underground railway system can easily work without a running tunnel.

6._______ An escalation complex consists of a stairways tunnel, a powerdriven station and a pull chamber.

VI. Restore the text (guess the words under the blots) and retell it to your partner.

The underground stations may be of different structural layout. There are

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offboarding platforms and boarding platforms.

Platforms are very important parts of the station concourses because they accommodate passengers and allow them enter, leave and change the trains. To determine the optimum capacity of an underground station it is necessary to consider the busy rate i.e. number of passengers carried through this station.

The main quantity index of any station is rated within the following limits:

-the quantity of passengers for an ordinary station must be equal to 20 – 30 % of a total train capacity;

-the quantity of passengers for the stations located near terminals, theaters etc. must be equal to 50 /n of a total train capacity;

-the quantity index for the stations next to large stadiums is equal to 100 % of an overall train capacity.

The dimensions of the station are influenced by the number of passengers to be carried.

The structural layout calls for due attention to the station length and height, the platform width and the length and height of the underground passages. The

width of an off-boarding platform must be 10 and in the case of a boarding platform – not less than 4 m each. Some platforms incorporate sliding doors, which open only when trains are ready to receive passengers. Moreover, the structural layout depends on the erection technique. As a rule, the floors of the shallow stations are made of flat panels. The structure of such stations involves columns, cross-bars and floor slabs as well as walling blocks.

Three vaults structures are employed for the deep stations. The central vault is used for platform and the side vaults are used for lanes. The vaulted stations can be erected with columns which serve as the principle bearing element or with the pylon frame.

Home Exercises

I.Memorize the words from Ex. I page 142.

II. Make a report on the difference between the usual railway and underground railway tracks.

Text 40 

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II. Scan the text and put the items in the correct order.

Tunnel lightning.

Tunnel maintenance.

Railway track maintenance.

Tunnel lining.

Shipping clearances testing.

Ventilation facilities.

Water discharging.

III. Read the text and check Ex. II.

TUNNEL MAINTENANCE

The current tunnel maintenance and care is much more expensive as against the bridge and culvert upkeep. A tunnel supervisor is in charge of a current supervision. He works side by side with a gang shift belonging to a maintenance section of the railway.

Needless to say there are no negligible problems in tunnel maintenance because a reliable tunnel operation during the service life depends on many fac-

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tors.

Special attention in the tunnel is given to the maintenance of the railway track which is examined daily. To maintain the railway track in proper condition means avoiding disastrous effects which may occur if a train derails. The tunnel supervisors’ attention is attracted by the gauge (1520 mm), the condition of the rail fastenings and joints. In addition two parallel rails must be supported at the same level.

The next problem to observe is a tunnel width and clear height to provide safe passage for trains. These shipping clearances are tested by a special measuring rod and a band or a special trolley equipped with a frame matching up the tunnel height and width.

The third problem is caused by the tunnel lining in case it is erected in the seismically active areas. The lining is influenced by the Earth’s crust shift and other displacement processes occurring within a massif. Tunneling through various sorts of rock can result in different effects and conditions influencing the lining especially when the blasting technique, is employed. Permanent supervision and inspection is set up for the lining elements in case of shifts in block joints or incipient cracks in concrete and iron cast segments. The tunnel supervisors use special screeds attached to the lining surface to watch the dynamics of the running processes.

Water discharging is considered to be another complicated problem turning to become most important one for the tunnels, which are driven under the severe climatic conditions. For instance, the railway tunnels along Abakan-Taishet mainline in Siberia can suffer from the ice crust in gutters in winter when the water freezes and binders or even blocks train running.

The gutters are built at both sides of the railway track for water discharging. The water entering the tunnel is calculated and rated value influences the dimensions of the gutters and their lengthwise grade. The gutters appear to be a vital element in tunnel operation and call for extra maintenance cost under low temperatures because they need heating or special encasement for warmth-keeping.

There are some more problems facing the tunnels and above all ventilation and lightning should be taken into consideration.

Ventilation is among the most complicated problems which vehicular tunnels face under operation. Ventilation facilities are essential because the underground road is a motor way within a tunnel structure. Air contamination calls for various types of ventilation facilities due to toxic auto emissions. Tunnel design takes full account of all the possibilities to provide a sound layout of the tunnel itself and efficient arrangement of ventilation facilities.

The simplest ventilation technique offers to arrange both ports at different levels providing natural ventilation due to the difference between air pressure at both ends.

One more idea of tunnel design may be applied to the large-diameter short

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