1. Bulldozers

The bulldozer (fig. 1) consists of a crawler or a wheel tractor equipped with the blade with a changeable knife. The blade can be set perpendicularly to the centerline of a tractor or at the angle of  be­tween the tractor centerline and the blade cutting knife (edge) in the horizontal plane that provides displacing the ground aside. In this case, a bulldozer is called a bulldozer with the rotary blade. The blade can be turned in the vertical plane that changes the angle of cutting. Sometimes the blade is turned in the vertical plane perpendicularly to the centerline of a tractor at 15–20°. In this case, a bulldozer is called as a universal one, as it can work like a grader. If the blade is installed perpendicularly to the centerline of a tractor the bulldozer with the rotary blade works as a bulldozer with the non-rotary blade. *Depending on the work carried on some device for pushing scrapers, rippers, bush-saws (bush-cutting ma­chines), ditchers, stumpers and other changeable equipment are sus­pended on the cradle of a bulldozer.

Fig. 1. Bulldozer: 1 - blade; 2 - thrusting cradle; 3 - hydraulic jack (advancing cylinder) of the blade drive

Very often, these accessories are suspended behind. According to the kind of the workpiece control bulldozers are divided into hydraulic and cable types. The cable types practically are not produced any more because of the slowness of the control, shorter power strokes and impos­sibility to reverse a transmitted effort.

It is possible with the help of a bulldozer:

• To mine extractions, to excavate on the hillsides by moving the soil into a bank at zero marks in a mountainous terrain;

• To smooth the relief in a mountainous terrain when roads lay­ing;

• To level the soil and building stuffs; to fill in trenches, pits, holes, and ditches;

• To grade construction and airfield sites;

• To clean the areas and routes of snow, bushes and so on;

• To set terraces on the declines of mountains and to make other activities.

It should be mentioned that the accuracy of grading is worse for a bulldozer than that one for a motor grader. That is owing to the installa­tion of the blade at the front of the machine.

A bulldozer can work as a mule with powerful scrapers at a trac­tive force up to 35 tn, when two mules up to 60 tn, and when three ones up to 85 tn. Some bulldozers can work in water at the depth up to 1 m.

By the engine power bulldozers are distinguished as very high-power ones (from above 400 hp), high - power (250 — 400 hp), mean middle (100 — 250 hp), low - power (20 — 100 hp) and small-sized (up to 20 hp).

The main parameter of a bulldozer is the tractive force; the main specifications are weight and power. These values arc interrelated. A machine has the rational design if its maximum tractive force is per­ceived as that one which exceeds (is superior than) the weight of the machine 1.1 – 1.2 times. In addition, the power corresponds to the us­age of the maximum effort at the speed of 2.5 km/h for crawler and 3.5 km/h for wheel tractors. The experience demonstrates that the weight is the steadiest parameter as the specific power per 1 ton of weight tends to the sluggish growth owing to the increase of maximum running speeds. It is known that the growth of working speed at a large load results in an intensified undercarriage wear and consequently the working speeds of crawler tractors used in construction at heavy conditions over the last 25 years have not changed almost.

*During the cutting-in operation of a bulldozer the cutting part of the blade puts deeper in the soil and simultaneously displaces it forward. *The soil separated from a massif is stored at the front of the knife mak­ing a prism of drawing.

*Cutting the soil is implemented until the prism of drawing reaches the upper edge of the blade. Then the blade is set on the surface of the soil. *After that, the blade is displaced roaming the prism of drawing to a place of unloading.

The recesses met by a bulldozer are filled in with the soil going from the blade; the elevations are sheared off by the knife.

*If the displaced stuff is required to be arranged, the blade at the motion of the bulldozer is uplifted over land a little. At idling, the blade is raised above the ground level at the altitude up to 700 mm.

*When bulldozer has the hydraulically driven blade, it is implanted in the soil under the forced conditions because of efforts developed by the hydraulic-circuit system: These efforts can reach 50 % and more weight of a tractor.

*The hydraulically controlled blade can be put into four positions: lifting; forced dropping; floating and locked.

The repositioning of the blade in the horizontal and in the vertical places for bulldozers with the rotary blade is implemented manually by shuffle of braces and by the rotation of the blade, and on some machines with the help of hydraulic cylinders. The cutting angle for potent bull­dozers is usually changed by the hydraulic cylinder.

Score: 20

Ex.7. Find in the text English equivalents to the following Ukrainian words and word-combinations:

під кутом; ріжучий ніж леза; забезпечувати пересування грунту вбік; бути повернутим у вертикальній / горизонтальній площині; виконувати роботу; засоби для поштовху (скрепери, розпушувачі, машини для підрізання кущів, прилади для копання каналів, корчувачі); навісне обладнання; обробний виріб; робочий хід; давати задній хід; копальні роботи з видобуванням на гірській місцевості; насип; проведення робіт із прокладенням доріг; розрівнювання землі; заповнення ям, канав; утворення виступів на схилах гір; перевищувати вагу; коефіцієнт максимального зусилля; постійний параметр; характерна потужність; уповільнення зросту; призма витягування; буферний режим; режим блокування; шляхом пересування підпорок; потужні бульдозери.

Score: 5

Ex.8. Fill in the blanks with the following words and expressions. Translate the sentences.

according to, with the help of, because of, to equip with, to correspond to, to consist of, to depend on, owing to, to be divided into, to carry on, to provide, to be called as, to be set, to be put into

1. The bulldozer … a crawler or a wheel tractor … the blade.

2. The blade can … perpendicularly to the centerline of a tractor.

3. The position of the blade … displacing the ground aside.

4. A bulldozer … a universal one, as it can work like a grader.

5. … the work … some equipment are suspended on the cradle of a bulldozer.

6. Bulldozers … hydraulic and cable types … the kind of the workpiece control.

7. The cable types practically are not produced any more … certain shortcomings.

8. It is possible to do a lot of work … a bulldozer.

9. The accuracy of grading is worse for a bulldozer than that one for a motor grade … the installation of the blade at the front of the machine.

10. The power … the usage of the maximum effort at the speed of 2.5 km/h for crawler and 3.5 km/h for wheel tractors.

11. The hydraulically controlled blade can … four positions.

Score: 11

Ex.9. Read the following and decide whether the statements are true or false. Correct them if necessary.

1. Some device for pushing scrapers, rippers, bush-saws, ditchers, stumpers and other unchangeable equipment are suspended on the cradle of a bulldozer.

2. Very often these accessories are suspended on one side.

3. A bulldozer can work as a mule with powerful scrapers but cannot work in water.

4. Such values of a bulldozer as: the tractive force, weight and power are interrelated.

5. The tractive force of a bulldozer exceeds the weight of the machine 1.1-1.2 times.

6. During the cutting operation the blade puts deeper in the soil and simultaneously displaces it forward.

7. The efforts developed by the hydraulic-circuit system can reach 50% and more weight of a tractor.

8. The repositioning of the blade for bulldozers with the rotary blade is implemented automatically.

9. The cutting angle for potent bulldozers is usually changed by the hydraulic pump.

Score: 9

Ex.10. Form ten sentences combining suitable parts of the sentences given in columns I and II.

	I		II
	The bulldozer		is raised above the ground level at the altitude up to 700 mm.
	The crawler and the wheel tractors		consists of a crawler or a wheel tractor.
	The rotary blade		are suspended on the cradle of a bulldozer.
	A universal bulldozer		is the tractive force.
	Some changeable equipment		are divided into hydraulic and cable types.
	Bulldozers		can be put into four positions: lifting, forced dropping, floating and locked.
	The main parameter of a bulldozer		can work like a grader.
	The main specifications of a bulldozer		are weight and power.
	At idling, the blade		can be turned in the vertical plane that changes the angle of cutting.
	The hydraulically controlled blade		are equipped with the blade with a changeable knife.

Score: 10

Ex.11. Find the correct term out of those given on the right.

A sharp part of a bulldozer that can be rotated.		idling
An earth-moving machine that is controlled hydraulically.		cradle
A site that is situated in mountains.		tractive force
An earth-moving machine that moves with the help of wheels.		trench
An angle which is fixed in the working equipment of a bulldozer while cutting.		rotary blade
The working mode of a machine when it involves the least amount of efforts to run the motions.		undercarriage
A kind of dropping that requires efforts.		wheel tractor
The main parameter of a bulldozer.		forced dropping
The structure that holds the wheels or crawler of a machine.		bulldozer
A long narrow hole dug into the surface.		angle of cutting

Score: 10

Ex.12. Find the equivalents to the following terms and word-combinations:

	crawler tractor		шасі
	wheel tractor		тягове зусилля
	changeable knife		кут зрізання
	angle of cutting		гусеничний трактор
	rotary blade		силове падіння
	cradle		канатний бульдозер
	hydraulic bulldozer		режим холостого ходу
	cable bulldozer		потужність двигуна
	mountainous terrain		траншея
	trench		колісний трактор
	tractive force		навісний ніж
	engine power		гірська місцевість
	undercarriage		опора
	idling		ротатне лезо
	forced dropping		гідравлічний бульдозер

Score: 15

Ex.13. а) Make the word-combinations using words given in lines 1 and 2.

1. tractive, crawler, engine, forced, mountainous, rotary, cutting, cable, changeable, wheel, hydraulic;

2. tractor, power, knife, tractor, angle of, force, dropping, bulldozer, blade, bulldozer, terrain.

b) Use them in sentences of your own.

Score: 11

Ex.14.

a) Find in the text 8 sentences marked with *. Translate them in writing paying attention to the attribute.

Notes:

У функції лівого означення Participle I перекладається дієприк­метником або прикметником:

The operator examines the moving parts of the machine carefully.

Оператор уважно перевіряє рухомі частини машини.

У функції правого означення Participle I перекладається на українську мову дієприкметниковим зворотом або підрядним означальним реченням:

The technique installing in our machine shop will greatly help us in our work.

Техніка, яка встановлюється в нашому цеху, значно допоможе нам у роботі.

У функції лівого означення Participle IІ звичайно перекладається дієприкметником пасивного стану теперішнього або минулого часу, або підрядним реченням. Participle IІ у сполученні з прислівником способу дії теж ставиться перед означуваним іменником:

Amots are composed of a positively charged core and electrons.

Атоми складаються з позитивно зарядженої серцевини та електронів.

У функції правого означення Participle II часто має при собі прийменник і перекладається означальним підрядним реченням неозначено-особового характеру:

At first sight the diesel spoken of looks like a gasoline engine.

Дизель, про який йде мова, на перший погляд подібний до бензинового двигуна.

b) Try to say by what part of speech the attributes are expressed (Participle I, Participle II, a gerund, an adjective):

the work carried on, the device for pushing, changeable equipment, the cutting part of the blade, the soil separated from a massif, the prism of drawing, the place of unloading, the displaced stuff, the hydraulically driven blade, the forced conditions, the efforts developed, the hydrauli­cally controlled blade.

Score: 10

Ex.15. Answer the following questions on the text:

1. What are the components of a bulldozer?

2. When can a bulldozer be called “a universal one”?

3. What is the criterion for dividing bulldozers into hydraulic and cable ones?

4. What work is it possible to do with the help of a bulldozer?

5. Can a bulldozer be distinguished by its engine power? How?

6. What are the main parameter and the main specifications of a bulldozer?

7. How is the blade raised above the ground level at idling?

8. How many positions can a hydraulically controlled blade be put into? What are they?

Score: 8

Ex.16. Translate the sentences into English. Mind your active vocabulary of Ex.5.

1. До складу бульдозера входять гусеничний трактор, або колісний трактор, що обладнані лезом із навісним ножем.

2. У бульдозерах із ротатним лезом лезо може бути повернено у різних площинах, що змінює кут зрізання.

3. Відповідно до типу управління обробного виробу, бульдозери поділяються на гідравлічні та канатні.

4. За допомогою бульдозера можливо виконати копальні роботи з видобуванням на гірській місцевості, розрівнювання землі та будівельних залишків, заповнення траншей, ям, дірок, канав та ін..

5. Основним параметром бульдозера є тягове зусилля, а основними специфічними рисами – вага та потужність.

6. Відомо, що результатом зросту робочої швидкості при великих навантаженнях є підвищення зношування шасі.

7. При роботі на холостому ході бульдозер може варіювати висоту підйому леза.

8. Зміна позиції леза виконується вручну, та, на деяких машинах, за допомогою гідравлічних циліндрів.

9. Кут зрізання для потужних бульдозерів змінюється гідравлічним циліндром.

Score: 9

Ex.17.Be ready to speak about the bulldozer as an earth-moving transport machine.

Score: 10

Total score: 155 points.

U N I T 3

Workpiece

Ex.1. Learn to recognize the following international words:

activity, structure, to fix, parallel, direction, part, spherical, act, geometry, energy, radius, tangent, segment, incidence, profile, to select, rationally, friction, abnormally.

Score: 2

Ex.2.Translate the following words into Ukrainian and state their part of speech:

different – difference – indifferent – to differ – differently;

enable – able – unable – to be able – ability – disability;

displacing – placing – placement – place – to place – to replace;

to develop – development – developed;

outstanding – outstand – to stand;

forward – to forward – forwarder;

to appear – appearance;

permit – to permit – permission – permitted;

to describe – description – descriptive

Score: 3

Ex.3. Form adverbs using the suffixes.

- able, -ful, -less, -ous, -ness.

control, continue, danger, value, replace, need, power, peace, use, life, change, desire, vary, weight, move.

Score: 4

Ex.4. Remember the meaning of these words and word-combinations:

friable ground	–	нещільна земля
to boost the output	–	підвищувати видобуток
jaws	–	затискні прилади
roky soil	–	кам’янистий грунт
solid ground	–	твердий грунт
to execute operation	–	виконувати роботу
to shear off	–	зрізати
undistorted soil	–	недеформована земля

Score: 8

Ex.5. Read and translate the text.