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Look carefully through the tables in Unit 8 and decide if the sentences are true (t) or false (f).
a) Ballast cleaners can be used not only in plain line tracks.
b) Track relaying machines can replace new panels while working on one and the same line.
c) Ballast regulators make track tamping more difficult.
d) General purpose cranes can be used in tandem with another cranes.
e) Single line gantries can be used only on double track sections of railway.
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Choose the appropriate word in b and put it into the gap in a.
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A
B
1. It can be used not only on _____________ but also switch and crossings, using an extended cutting bar.
a. travel
2. A ballast regulator ploughs and sweeps __________ after installation to tidy the track and facilitate tamping.
b. ballast
3. It is self propelled and can _____________ at speeds of up to 72 km per hour to and from the worksite.
c. plain line track
4. It can be used in __________ with another crane for lifting track panels and is particularly useful for switch and crossing work.
d. crane jibs
5. These machines consist of two __________ mounted on a self propelled wagon.
e. tandem
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Make up sentences choosing the correct information to characterize road construction machines.
Road construction machines perform well as they
a) are designed specifically for track-laying duties
b) carry millions of passengers
c) are intended to perform alignment of railroad track, lining of track and tamping of ballast
d) accept imposed dynamic and static loads as cars, locomotives and trains
e) unclip the old rail and shift it out to the side, take out the old sleepers and dispose of them in wagons, retrieve new sleepers and drop them in position, and finally clip in the new rail
f) can store excess ballast and drop it in areas where ballast is depleted
g) achieve high speed and great transport capacity.
Unit 14
You are going to read a text which consists of nine paragraphs. First read the opening of each paragraph.
1) Earth digging operations require…
2) It is impossible to start on a construction job without a good deal of preliminary levelling the site. To carry out this work one must employ the earth-moving equipment...
3) Plant for site preparation and excavation can be divided into four classes…
4) Bulldozers of different types belong to the first class of machines…
5) A scraper which belongs to the second class of earth moving machines is simply a large box with an open mouth dragged along the surface of the ground until it is full.
6) The universal excavator is an earth-moving machine that can be equipped with different attachments known under the following names…
7) Some decades ago only rope-controlled excavators were in use.
8) With the wheeled excavator, which is considerably lighter than the crawler mounted one, means to provide additional stability are incorporated. Before starting digging operation outrigger arms provides for …
9) A recent model incorporates a telescopic dipper arm: when extended it can dig deeper and has a greater discharge height and when retracted it produces its greatest digging force at the bucket…