Text 4a Sleepers

Read and translate the text.

The rails of a track are fastened to supports which rest on the ballast. These supports called crossties (ties, sleepers) have an Important function in determining the behavior of the track: they keep the rails at exact gauge end transmit stresses caused by the passage of trains to the ballast. Modern ties must have a long life – and high resistance to biological and mechanical destruction.

Since railway construction started wood has been used for the production of railway sleepers. Oak and other hardwoods are the best woods for manufacturing ties because they are heavy and close – grained, and are less liable to decay, last longer than nearly all other kinds of wood.

So many of the hardwood trees hare been cut down that ties from such trees have become very expensive, and now railroads use ties out from pine fir, and other cheaper but less durable varieties of wood. To make these ties of soft – wood last longer they are impregnated with preservatives which will keep them from biological destruction.

The most common method of preserving ties is to treat them with creosote. Other chemicals are also employed for wood preservation. In some treating plants the chemical preservatives including creosote are mixed with petroleum before applied to the wood.

To provide deeper penetration of the preservatives ties should be incised and seasoned before they are treated with special sub­stances. Incising increases receptivity for the preservative, and seasoning is of primary importance in reducing the moisture within ties’ interior so that they will be able to accept more of the pre­servative that is vital to their having a long and useful life.

In nearly all modern wood – treating plants, the preservatives are forced into the wood under pressure. Another method which rail­roads have generally adopted to make wooden ties last longer is to put steel tie – plates on the ties under the rails. The tie – plates provide a broader bearing surface for the weight of the trains, they also maintain the line and the gauge of the track.

At present not only wood is used for manufacturing ties. Steel sleepers can also be found on the railroads Of many countries. Con­crete sleepers are being used on a large scale, and they show ten­dency to replace, wooden crossties in future.

Exercise 1. Render the following word combinations in Russian.

To rest on the ballast, the behavior of the track, to keep the rails at an exact gauge, to transmit stresses to the ballast, a long life-span, high resistance to biological and mechanical dest­ruction, to be less liable to decay, to last longer, varieties of wood, to impregnate with preservatives, to keep ties from biological destruction, methods of preserving ties, to treat sleepers with creosote, to employ chemicals for wood preservation, treating plants, to provide deeper penetration of the preservatives, receptivity for the preservative, to reduce the moisture within ties' interior, to accept more of the preservative, to force the preservatives, into the wood under pressure, to put steel tie –plates on the ties under the rail, the only material, on a large scale.

Exercise 2. Complete the sentences according to the contents of the text.

1 Sleepers are supports to which ...

2 Ties keep the rails at ...

3 Crossties transmit stresses ...'

4 Modern ties must have a long life-span and ...

5 Sleepers of oak and other hardwoods are less liable ...

6 Ties of soft-wood are cheaper but ...

7 To make ties of soft-wood last longer ...

8 Creosote and other chemicals are employed ...

9 The preservatives are forced ...

10 To provide deeper penetration of the preservatives ties ...

11 Incising increases receptivity ...

12 Seasoning reduces ...

13 Another method of increasing the life-span of ties is ...

14 Wood is not the only ...

15 Steel are concrete sleepers are used ...

Exercise 3. Answer the following questions:

1 What are railroad sleepers?

2 What is the function of sleepers in the track?

3 What properties must modern ties have?

4 What material are crossties mostly made of?

5 Why do we consider oak and other hardwoods the best material for manufacturing ties?

6 Why are sleepers of soft-wood subjected to a special treatment?

7 What chemicals are used to treat crossties?

8 In what way is this process realized?

9 What should be done-to provide deeper penetration of the preserva­ tives?

10 What does incising increase?

11 Why is it important to season ties?

12 What other methods of increasing the life-span of ties are des­cribed in the text?

13 What do the tie-plates provide?

14 What other materials are used for manufacturing sleepers?

Exercise 4. Speak about the ties using the following table.

ties wooden crossties steel ties concrete sleepers

are important are used are made are liable are treated are impregnated are incised are seasoned

to decay on a large scale with preservatives to reduce the mois­ture within ties' in­terior to increase recepti­vity for the preser­vative in determining the behavior of the track to keep the rails at an exact gauge to transmit stresses to the ballast of hardwoods of soft – wood to keep ties from bio­logical destruction with creosote

Exercise 5. Speak about the advantages and disadvantages of the ties made of different kinds of wood.

Use the following words and expressions:

to manufacture, oak, hardwood, heavy, close-grained, less liable to decay, to last long, expensive, pine, fir , soft-wood, cheap, less durable.

Exercise 6. Speak about the methods of increasing the life-span of wooden sleepers.

Use the following words and expressions: to impregnate with pre­servatives, to treat with creosote, to employ chemicals for wood preservation, to provide deeper penetration of the preservatives, to incise, to season, to force the preservatives under pressure, to employ steel tie-plates.

Exercise 7. Listen to the tape-recorded dialogues and practice them in pairs.

Dialogue 1

A.: What is the function of sleepers?

B.: They keep the rails at an exact gauge and transmit stresses to the

ballast.

A.: What materials are used for manufacturing ties?

B.: Sleepers are made of wood, steel, concrete.

A.: What should be done to make wooden ties last longer?

B.: To make wooden sleepers more durable they are impregnated with

preservatives.

Dialogue 2

A.: What chemicals are used for treating ties?

B.: Treating plants employ creosote, petroleum and other chemicals

for wooden ties preservation.

A.: What should be done to provide deeper penetration. of the pre­

servatives ?

B.: Before treating sleepers should be incised and seasoned.

A.: How is the process of impregnating ties with chemicals reali­zed?

B.: The preservatives are forced into the wood under pressure.

Exercise 8. Discuss the problems of the permanent way in pairs. Beginyour dialogues according to the pattern.

A.: There's something 1 want to ask you. May I?

B.: Sure, you may t Why not? Go ahead!