IV. Read and translate the text

On existing railways the design and construction methods are largely dictated by the absolute requirement to continue to operate trains safely during the construction period.

Superstructures for bridges and structures, both over and under railway tracks, need to be constructed during possession of the railway, at night or weekends when railway traffic is the lightest.

Often it is possible to carry out work on superstructures during railway traffic hours but this often involves prior construction of temporary or protective works during possession of the tracks. The conventional method of reconstruction of abutments is to install 'waybeams'. These waybeams can be supported on timber piles. This then allows construction of the new abutment beneath.

Superstructures for railway bridges on existing lines, which need partial or complete renewal, can be placed in position by one of the following basic methods:

a) Piecemeal lifting in; b) Complete lifting in; c) Lateral rolling-in;

d) Wrapping round existing structure; e) Launching.

Lateral repositioning of bridge superstructures has for many decades been done during possession using steel balls. The rolling-in trolley usually incorporates a one hundred tonne capacity jack and the lateral pull to move the bridge is provided by cable winches, either manual or power driven. In recent years heavy bridges have been slid into position rather than rolled using skates. By this method, large bridges are usually moved into position about 100 mm higher than their final level and then jacked down once in the correct location on plan.

Rail mounted cranes are available for lifts of units on most main line railways. These are usually limited in capacity to not more than 75 tonnes at minimum radius and may deal with derailments or other emergencies.

When it is possible to get road mounted cranes to the site of the work, they are often much better due to their flexibility in operation and increased capacity and reach. It is now possible to hire road cranes with a capacity up to 500 tonnes.

Special precautions need to be taken when using both road and rail cranes on railways having overhead electrification.

V. Answer the questions.

1. What are the bridge reconstruction methods on railways dictated by?

2. Why is it better to perform reconstruction works during possession of the railway?

3. What are the conventional abutment reconstruction methods?

4. What are the basic bridge superstructure reconstruction methods?

5. What equipment can be used for bridge reconstruction?

VI. Are these statements True or False:

1. On existing railways the design and construction methods are largely dictated by the absolute requirement not to stop train movement.

2. Possession of the railway is the time when the traffic of trains is the heaviest.

3. Installation of waybeams allows to construct a new abutment beneath the existing bridge.

4. In recent years heavy bridges have been slid into position rather than rolled using skates.

5. Road cranes have lower capacity than rail ones.

VII. Complete the sentences with the words from the box.

capacity possession superstructure waybeams jack cranes

1. Superstructures for bridges and structure need to be constructed during ____________of the railway.

2. The conventional method of reconstruction of abutments is to install ______.

3. Lateral repositioning of bridge __________has for many decades been done during possession using steel balls.

4. The rolling-in trolley usually incorporates a one hundred tonne capacity ___.

5. It is now possible to hire road cranes with a _________up to 500 tonnes.

6. Rail mounted rail ________are available for lifts of units on most main line railways.

VIII. Use the information from the text to speak on problems of bridge reconstruction. The following plan will help you.

1. The name of the object/ 2. The place of the construction site./ 3. The obstacle which the bridge crosses (a valley, a river, a gorge)./ 4. The structure that is necessary to reconstruct (a pier/ an abutment/ a superstructure)./ The method of reconstruction (conventional method of reconstruction/piece-small lifting in/lateral rolling-in/launching./ 5. Equipment used for reconstruction (cranes, jacks, winches, etc).

SECTION VI. PRESENTING A COMPANY

Unit 9. THE LARGEST BRIDGE DESIGN COMPANIES

Match the words and collocations (1 – 10), and their definitions (a – j).

1. subsidiary	a) the money that company makes, especially after paying the costs of producing and selling goods and services
2. head office	b) a company which is owned by a larger company
3. warehouse	c) a building where large amounts of goods are made using machines
4. branch	d) a company that contracts to fulfill the work
5. profit	e) the main building of a large organization
6. employee	f) a place where a company provides help for customers who use its products or services
7. factory	g) a division or office of a large organization
8. contractor	h) the company or authorities that pay for the product or goods
9. customer	i) someone who is paid regularly to work for a person or an organization
10. store	j) a large building for storing things before they are sold, used or sent out to shops.