- •Предисловие
- •Part 1 construction equipment Unit 1 construction plant
- •Text a construction plant
- •Vocabulary
- •Video 1
- •Tractors
- •Text b tractors
- •Vocabulary
- •Unit 2 earth movers: excavating machines
- •Text a excavating machines
- •Vocabulary
- •Match a and b.
- •Say what its total height was in metres and what its bucket capacity was in cubic metres?
- •Work in pairs. Ask and answer questions about Marion 6360.
- •Video 2
- •Video 3
- •Text b backhoe loaders
- •Video 4
- •Text с draglines
- •Schematic view of a dragline
- •Video 5
- •Unit 3 earth movers: bulldozers, graders, scrapers and loaders
- •Vocabulary
- •Video 6
- •Main manufacturers of telescopic loaders Russia imports (2016)
- •Komatsu d575a bulldozer
- •Text b scrapers, graders and loaders
- •Vocabulary
- •Russia’s import of telescopic loaders (2016, in %)
- •Video 7
- •Video 8
- •Unit 4 cranes
- •Text a cranes
- •Video 9
- •Tower cranes
- •Text b tower cranes
- •Vocabulary
- •Video 10
- •Vocabulary
- •Video 11
- •Video 12
- •Video 13
- •Text b crossties, ballast and turnouts
- •Vocabulary
- •Functions of the track
- •Video 14
- •Unit 2 track maintenance machines
- •Video 15
- •Vocabulary
- •Video 15 Part 1
- •Vocabulary
- •Video 17
- •Список использованных источников
- •Содержание
- •Construction equipmentand track maintenance machines дорожные, строительные и путевые машины
Text b crossties, ballast and turnouts
Railroad ties, also known as crossties or sleepers are the lateral support for the rails. The wooden tie is treated with creosote to improve its life. Wooden ties provide sufficient strength and are relatively inexpensive compared to concrete ties. Railroads employ concrete ties on heavily used main lines. The one drawback of concrete is that because of its rigid qualities it does not have the same flexibility as wood. However, thanks to its strengths and longevity over wood, in the future you will almost surely see more and more main lines employing concrete ties.
Ballast is used to distribute the load from the ties, to prevent the track from buckling and to provide drainage. Ballast also acts as a support base for the railroad track giving it strength and rigidity but also allowing for flexibility when trains pass over. Ballast must regularly be cleaned or added as dirt reduces ability of ballast to properly drain water. Crushed rock is the best material for ballast; however, gravel, sand, asbestos, and shell rock are also used.
A turnout, also known as a point and a switch, is used to guide trains from one track to another. It typically consists of a frog, check rails and two switch rails. The switch rails may be moved left or right, under the control of the signaling system, to determine which track the train will follow.
Vocabulary
Match the term with its definition.
1) ballast |
a) the distance between the inner faces of the rail heads |
2) nut |
b) a metal part with a hole whose surface is threaded for screwing onto the corresponding bolt |
3) rail |
c) the means of directing a train from one track to another |
4) tie / sleeper
|
d) a piece of wood or concrete that is set in ballast and supports the rails to distribute the train’s load and keep the rails parallel |
5) joint bar / fishplate |
e) a steel fixture on a sleeper which secures the rail in the correct position |
6) spike |
f) the place where ends of rails meet in the track |
7) turnout |
g) a steel bar that is attached to sleepers; the train’s wheels roll along it |
8) gauge |
h) the trackbed upon which ties are laid |
9) tie plate / chair |
i) a steel plate that is fitted to the two sides of the rail webs to join them end to end |
10) joint |
j) a large nail with an offset head that fastens the foot of the rail to the wooden sleeper |
Comprehension
Exercise 1. Decide if the sentences are true or false.
Good quality ballast is made of crushed stone.
Wooden ties have longer life than concrete ones.
Concrete is more flexible than wood.
Drainage is keeping water away from the track.
The switch rails are the moving part of the turnout.
Exercise 2. Complete the table. Choose from the list.
