Characteristics of Railway Electrification

Unit 6

Ex.9. Translate the sentences into Russian and make your own sentences according to the model.

Safety checklist

Ex.8. Use the conversation from ex.7 to fill in a safety checklist.

Ex.7. Listen to the conversation between two electricians and complete the sentences.

Ex.6. Fill in the gaps in the sentences with the words from the box.

Ex.5. Match the words (1-4) with their definitions (A-D).

1. shock; 2. paralyze; 3. lockout/tagout procedure; 4. hazard

A. something that is not safe;

B. to make the muscles stop moving

C. to pass electricity through the body;

D. a rule to lock energy sources and label electrical equipment when it’s being

repaired.

burn, risk, de-energise, live wire, static electricity, electrocution

1. Touching a (1)… is very dangerous.

2. A serious (2)… should be seen by a doctor.

3. Electricians (3)… sockets before they work on them.

4. (4)… can be prevented by following safety rules.

5. (5)… often builds up on door knobs.

6. There is always a (6)… of getting hurt at work.

Electrician 1. Thanks for letting me (1)….

Electrician 2. No problem. This job has a lot of (2)… It’s important to learn (3)…

Electrician 1. So yesterday you were telling me about the (4)…

Electrician 2. Right. Basically, never start working on (5)… until you know the (6)….

Electrician 1. Okay, that makes sense. Is that all?

Electrician 2. No. Then you (7)… so that no one can turn it on again.

Electrician 1. Got it.

Electrician 2. Finally, (8)…. being repaired.

Name of safety procedure:____________________________________________

What are the steps of the procedure?____________________________________

_________________________________________________________________

Why is the procedure important?_______________________________________

_________________________________________________________________

1. It is important to follow electrical safety rules.

2. It is useful to de-energise power sources before working.

3. It is dangerous to touch faulty wiring.

4. It was easy to replace flicker bulbs.

5. It is advisable to carry out lockout procedures.

6. It is necessary to avoid electrical hazards.

7. It was possible to install fixed wiring.

8. It is impossible to reduce electrical load in winter.

9. It must be interesting to study electricity.

10. It can be risky to deal with any type of electricity.

Ex.10. Make a brief report about:

- the reasons of electrical fires;

- electrical fire precautions;

- why safety is important;

- the rules that can keep people safe.

Electric railways use electric locomotives to haul passengers or freight in separate cars or electrical multiple units, passenger cars with their own motors. Electricity is typically generated in large and efficient generating stations, transmitted to the railway network and distributed to the trains. Some electric railways have their own generating stations and transmission lines but most of them purchase power from general electric grid. The railway usually provides its own distribution lines, switches and transformers.

Power is supplied to moving trains with a conductor running along the track that usually takes one or two forms. The first is an overhead line or catenary wire suspended from poles or towers along the track or from structure of tunnel ceilings. Locomotives or multiple units pick up power from the contact wire with pantographs on their roofs that press a conductive strip against it with a spring or air pressure.

The other is a third rail mounted at track level and contacted by a sliding “pick-up shoe”. Both overhead wire and third-rail system usually use the running rails as the return conductor but some systems use a separate fourth rail for this purpose.

In comparison to the diesel engine, electric railways offer substantially better energy efficiency, lower emissions and lower operating costs. Electric locomotives are usually quieter, more powerful and more reliable than diesels. They have no local emissions, which is an important advantage in tunnels and urban areas. Some electric traction systems provide regenerative braking that turns the train’s kinetic energy back into electricity and returns it to the supply system to be used by other trains or the general grid. While diesel locomotives burn petroleum, electricity is generated from diverse sources including many that do not produce carbon dioxide such as nuclear power and renewable forms including hydroelectric, geothermal, wind and solar energy.

Disadvantages of electric traction include high capital costs that may be inefficient on lightly trafficked routes; a lack of flexibility since electric trains cannot operate on non-electrified tracks and a vulnerability to power interruptions. Different regions may use different supply voltages and frequencies which causes complications to train service. The limited clearances available under catenaries may prevent efficient double-stack container service. The lethal voltages on contact wires and third rails are a safety hazard to track workers, passengers and trespasses.

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