Unit 2 track maintenance machines

Start up

Discuss these questions.

1. Why does the track need to be maintained?

2. What are the functions of track maintenance machines?

Reading

Read the text quickly. Write the number of the paragraph (1-6) that gives you the information (a - f).

1. How tamping is performed

2. Stabilisation and consolidation

3. Functions of maintenance machines

4. From manual labour to mechanization

5. Levelling, lining and tamping must be performed

Text A

1 In the past, track maintenance tasks were carried out by manual labour, but today are performed using powerful machines.

2 Machines are available to do all the necessary track maintenance tasks: taking out and placing new rail, either in bolted lengths or with long welded lengths, pulling out old sleepers, putting in new sleepers, pulling or driving spikes, applying rail anchors, skeletonizing track, excavating and replacing worn ballast, tamping ballast, cleaning ballast, spreading and distributing new ballast, lining the track, grinding rails, cleaning the track from snow, etc. Some machines are equipped to perform more than one task – for example, ballast tamping combined with track lining and levelling.

3 Safe and comfortable travel in a train is only possible on tracks lying in the correct geometrical position. Levelling, lifting, lining and tamping machines make it possible to produce this state of the track. When a train travels over a track, it generates enormous forces. The entire track consisting of rails, sleepers and ballast is an elastic system that deforms and returns to its original position. Over the long period this high stress results in deterioration of the track geometry. To avoid such a situation, tracks should be maintained at regular intervals – this includes levelling, lifting, lining and tamping.

4 How is tamping performed? The tamping tines compact the ballast under the sleeper with a squeezing movement. The tamping tines vibrate and this directional vibration produces a homogeneously compacted ballast bed.

5 After laying a new track and following tamping work or ballast bed cleaning, some of the ballast stones are not in an ideal position to each other. This means that there is a lack of stability which is necessary to consolidate the track in the ballast ideally. The dynamic track stabilising machine has a vibrating unit which holds the track in position and applies vibration to simulate the passage of trains. This is transmitted to the ballast bed achieving re-arrangement of the ballast stones to produce a denser structure.

Exercise 1. Match the word with its meaning.

1) lining the track	a) подбивка балласта
2) placing new rail	b) шлифовка рельсов
3) putting in new sleepers	c) рихтовка пути
4) driving spikes	d) распределение балласта
5) applying rail anchors	e) вывешивание пути
6) skeletonizing track	f) выправка пути
7) replacing worn ballast	g) установка противоугонов
8) tamping ballast	h) укладка новых рельсов
9) cleaning ballast	i) укладка новых шпал
10) spreading ballast	j) забивка костылей
11) grinding rails	k) замена старого балласта
12) levelling the track	l) очистка балласта

Exercise 2. Read the text again and find English equivalents.

Задания на техническое обслуживание; ручной труд; длинные сварные плети; загрязненный балласт; более одного задания; безопасная и удобная поездка; производит огромное давление; деформируется и возвращается в свое первоначальное положение; чтобы избежать такой ситуации; сжимающее движение; неустойчивость; более плотная структура.

Exercise 3. Complete the sentences with the words from the box.

a) position b) tines c) geometry d) ballast e) elasticity

1. Tamping is used to hold the tracks in the correct geometrical _____.

2. For the track to work properly, the sleepers need to sit firmly in the _____.

3. Fouling reduces the _____ of the track, the water permeability and the durability of the track geometry.

4. Tamping _____ pack the ballast under the sleeper to produce a stable sleeper bed.

5. Stabilisation increases the quality reserve of the track and produces a more durable track _____.

Exercise 4. Match the synonyms.

1) carry out	a) uniformly
2) tamp	b) perform
3) oscillate	c) old
4) homogeneously	d) dirty
5) produce	e) wear
6) deterioration	f) vibrate
7) foul	g) compact
8) worn	h) generate

Exercise 5. Study the picture and complete the sentences with the words on the right.

The 1)_____ penetrate the ballast 2)_____ from above and 3)_____ the ballast under the 4)_____ with a squeezing movement. Two factors are decisive here. Firstly, all tamping tines work with the same pressure; and secondly, the tamping tines 5)_____ with the ideal frequency of exactly 35 6)_____. This directional, linear 7)_____ combined with the non-synchronous tine movement produces a 8)_____ compacted ballast bed.

a) compact b) tines c) vibrate d) vibration e) bed f) homogeneously g) hertz h) sleepers

Speaking

Discuss these questions with your partner.

1. How is tamping performed?

2. Why should the track be stabilised?

Listening