Unit 1

Grammar: Tenses;

Emphatic construction

Text A

GENERAL CLASSIFICATION OF MACHINES

Machines employed for construction and road making can be classified according to their purpose as follows:

1. Transporting facilities: crawlers and wheel –mounted tractors, trucks, general and special-purpose trailers and semi-trailers.

2. Materials handling equipment: winches, cranes, hoists, conveyors, air-operated equipment, loading and unloading machines.

3. Machines for earthwork: bulldozers, scrapers, elevating graders, towed graders, revolving shovels, hydraulic equipment and compactors.

4. Machines for preparing and placing concrete mixes: mixers, vibrators and vacuum plants.

5. Machines for laying stabilized pavements: bitumen storage equipment, machines for preparing asphalt-concrete mixes, for placing and compacting asphalt-concrete, machines manufacturing reinforced concrete products, machines placing reinforced concrete slabs, etc.

All of the above machines can be classified by the working process (continuous action or intermittent action), the prime mover (driven by electric motors or by internal combustion engines), mobility(stationary or mobile).

All machines are also characterized by definite parameters. Thus, the main parameter of a power shovel or a scraper is the capacity of the bucket, for cranes the main parameter is the maximum load-lifting capacity, for a bulldozer – the pulling effort, etc.

Among the main parameters of a machine there are capacity, weight, engine, power, overall dimensions, working and travelling speeds, etc.

For most machines per hour capacity is determined by the volume or weight of scooped material.

Active Vocabulary:

facility - оборудование, приспособление

purpose - цель, назначение

trailer - прицеп

equip - оборудовать

winch - лебедка, ворот

hoist - подъемник

earthwork - земляные работы

scraper - скрепер

elevate - поднимать

revolving shovel - ковш, вращающаяся лопата

compactor - уплотнитель

continuous - непрерывный

intermittent - периодический, циклический

prime mover - пусковой (основной) двигатель

pendant - навесной

self-powered - самоходный

mobile - подвижный, перемещаемый

capacity - емкость, производительность, мощность

pull - тянуть, тащить

dimension - размер

determine - определять

scoop - ковш, вычерпывать

Exercise 1.Answer the following questions:

1. How can the machines be classified according to their purpose?

2. What equipment is applied for handling materials?

3. What types of machines for earthwork do you know?

4. What machines are used for preparing and placing concrete mixes?

5. What is the main parameter for a power shovel?

6. How can cranes be characterized?

7. What are the important parameters of a machine?

8. How is the per hour capacity of a machine determined?

2. Exercise Define the tense of the predicates and translate the following sentences:

1. Tractors are mounted either on crawlers or on wheels.

2. Machines have been employed for construction purposes since early times.

3. We need different machines.

4. They have been testing the new transporting facility for a month.

5. Special purpose trucks were used to deliver building materials.

6. Before they installed modern hoisting equipment, simple winches had been

used.

7. The builders are using vibrators to compact concrete mix.

8. Concrete slabs will be placed with a tower crane.

9. They will replace old conveyor system next month.

10. The new asphalt pavement will have been laid by the end of the week.

Exercise 3.Translate the following sentences paying attention to the Emphatic Construction:

1. It is an electric motor that is used to drive most machines in modern shops.

2. It was steam that first began to move machines.

3. It is the construction site where most of the cranes are used.

4. It will be in June when the development plan is carried out.

5. It is a mechanic engineer who designs new machines for our industry.

Exercise 4.Translate the text without a dictionary:

Text B

POWER MACHINES

If one looked around a machine shop, he could see two types of machines: driven machines and driving or power machines.

Power machines are connected with driven machines by several methods. In the older workshops, belts and pulleys were much used but they are gradually disappearing. It is an electric motor that is used to drive most machines in modern workshops. Power is transmitted to the motor from the electric generators by means of insulated electric cables. Power may also come from a steam or gasoline engine.

Selection of power for a given operation is one of the first problems that must be solved in planning a new construction job. Whether the power is built into the machine, as in a tractor, or must be supplied separately, as with a pile driver, it is necessary to know what the manufacture’s rating of power is in terms of performance. Too much power means spending too much money. Too little power means that the job cannot be performed. Moreover, as machine wears with time and use, power may be lost or wasted. A knowledge of fundamentals of power finds application during operation as well as in planning.

Power may be defined as the rate of producing work. Its most commonly employed unit of measurement is the horsepower. The equivalent of 1 hp is 33,000 ft-lb per minute or 746 watts (w).

Notes:

connect - соединять

gradually - постепенно

disappear - исчезать

insulate - изолировать

Unit 2

Grammar: Participles;

Absolute Participle Construction

Text A

MECHANICAL HANDLING

At present plants, factories and building sites are equipped with various mechanisms and machinery that do the job of loading and unloading, lifting and positioning materials in place.

Depending on its purpose materials handling equipment consists of the following three main groups:

1. Hoisting equipment: winches, jacks, hoists and cranes for intermittent operation.

2. Conveying equipment: intermittently acting (rope-and-bucket) and continuously acting conveyors (belt, bucket, screw, vibration type, etc.), cableways, air-operated equipment.

3. Loading equipment for intermittent and continuous operation. Load handling equipment includes rail-mounted cranes, fork lift trucks and mobile cranes.

Loads are now handled at greater speeds and at smaller costs, possible damage has been brought to the minimum. Most materials loaded and unloaded are palletized. Pallets are handled by fork lift trucks. Fork lift machines are used in ever increasing numbers to carry loads. Loads that cannot be palletized are handled by cranes.

The lifting appliances include stationary and mobile cranes. Much work is done by quay cranes. In the last few years, quay cranes have been greatly improved.

Although quay cranes have become larger and more efficient it is the mobile cranes and particularly the fork lift trucks that revolutionized the handling methods. The fork lift truck is now used to lift, convey and stack loads.

Mechanization of handling materials ensures growth of speed of loading and unloading operations.