Exercise 2. Match a word in A with a word in B.

A	B
	A locomotive	a	A flow of electric charge.
	A cab	b	The overhead power line system.
	A railcar	c	A 4 or 6-wheeled truck used in pairs under long-bodied railway vehicles.
	A motor coach	d	The compartment of a locomotive in which the driver sits.
	A trailer	e	A machine that converts energy into mechanical motion.
	Current	f	A self-propelled engine, usually electric or diesel powered that pulls or pushes freight or passenger cars on railroad track.
	Electrification	g	A passenger vehicle in a multiple unit train which is provided with traction power equipment.
	A catenary	h	A passenger vehicle in a multiple unit train which has no traction power equipment.
	An engine	i	Self-powered vehicle capable of operating as a single unit and often passenger carrying.
	A bogie	j	The process of wiring and equipping the railroad for the use of electric power.

Reading and translation

Exercise 1. Read the text and answer the questions.

1) How is motive power provided for trains?

2) What does the word ‘self-sufficient’ mean?

3) What is an important drawback of diesel locomotives?

4) What is the greatest drawback of electrification?

Motive Power

Vehicles which provide motive power to haul trains include locomotives and motor coaches. Motive power is classified into:

- self-sufficient units which generate their own power from fuel such as diesel locomotives, gas turbine locomotives, locotractors, diesel trains, turbotrains, railcars, and steam locomotives;

- not self-sufficient units which take power from an outside source of electricity such as electric locomotives and electric trains.

Locomotives are subdivided in their usage in rail transport operations into:

- mainline locomotives

a) goods (freight) locomotives,

b) passenger locomotives,

c) mixed traffic locomotives;

- shunting locomotives/shunters;

- locomotives for both line and shunting operations.

These categories determine the locomotive’s size, starting tractive effort and speed.

A number of diesel or electric units can be combined according to the power needed for a particular train with only one crew required for all the units.

Electric locomotives. Unlike diesel locomotives, which produce their own power, electric locomotives convert the electric power that is generated elsewhere.

Electric locomotives can be divided into those using alternating current (AC) and those using direct current (DC). They pick up current from an overhead wire. An electric locomotive consists of a mechanical part, electrical and pneumatic equipment. A mechanical part comprises a body, bogies, brake equipment, and coupling and drawgear. A body is usually of all-metal construction and contains electrical equipment. A body is supported on 2- or 3-axle bogies, and they, in turn, on wheel sets. Bogies are composed of frames with traction motors on them.

An electric locomotive has a number of advantages:

- It can develop greater power compared to diesel locomotives.

- It is cleaner and quieter in operation.

- It requires little time in the shop for maintenance.

- Its maintenance costs are low.

- It has a longer life than diesels.

The greatest drawback of electrification is the high capital investment and maintenance cost of traction substations and overhead wires.

Electric trains.Electric trains are used for suburban and intercity passenger service on electrified lines. They are formed of 4, 6, 8, 10 or 12 motor coaches and trailers.

The term multiple unit or MU is used to describe self-propelled coaches (carriages, cars) coupled with other units and controlled from one driving cab. MU coaches can be motor units (motor coaches) or trailer units. Multiple units are classified by their power source and are of two main types: electric multiple unit (EMU) and diesel multiple unit (DMU).

Diesel locomotives.A diesel locomotive has its own power supply unit (usually a diesel engine). A diesel is an internal combustion engine with the efficiency of 40-42%. This engine drives the wheels by mechanical, hydraulic or electric transmission. Of the three, electric transmission is most popular.

A diesel locomotive has a number of advantages:

- Being self-sufficient it is not connected with an overhead wire.

- It can be operated in any climate.

- It does not require costly catenary and traction substations.

A diesel locomotive has also a number of disadvantages:

- It pollutes the environment.

- It has a great number of friction parts.

- It requires the delivery of fuel and lubricants.

- The run is limited in terms of fuel provision.

- There is a fire risk.

- A diesel engine produces a lot of noise.

The diesel locomotives excel in shunting where intensity of use is high.

Diesel trains.A diesel train is formed of motor coaches and three or more trailers used to transport passengers on non-electrified sections.

Railcars. A single self-propelled carriage is called a railcar.

Locotractors. A locotractor is a locomotive with a 150 kW carburetor engine.

Gas turbine locomotives.A gas turbine locomotive is a locomotive that uses a gas turbine to drive an electrical generator or alternator. The electric current thus produced is used to power traction motors. After the 1973 oil crisis and the subsequent rise in fuel costs, gas turbine locomotives became uneconomical to operate, and many were taken out of service.

Date: 2016-01-03; view: 1187

<== previous page	\|	next page ==>
Exercise 1. Some words are often used together. Fill the gaps in sentences 1-8 with a word from the list that goes with the word in bold.	\|	Listening and speaking

doclecture.net - lectures - 2014-2024 year. Copyright infringement or personal data (0.007 sec.)