2. Scrapers

The earth-moving machine set in motion by its own engine or a drive truck and designed for level-by-level shearing off the soil, trans­porting and unloading is called a scraper (the fig. 3.). Moreover, after that in most cases, except for models with an unloading back, scrapers are also used for grading the ground and for its compaction.

Scrapers can be of the pull-type, i.e. the trailed and semi-trailed (two-wheeled) – self-propelled type. The trailed scraper works with a crawler tractor 1. It consists of a wheeled bucket (a scraper bowl or a scoop) 2, equipped with a hinged type shutter (flap), a control system of a bucket (scoop), a coupling device, which the scraper is attached to a tractor with, and a buffer unit 3. The scraper bowl removes a strip of earth at a time. A self-propelled scraper consists of a semitrailer scoop for a single-axle, less often for a bi-axle wheel drive truck (fig. 3., b, c, d), control system, and coupling and buffer devices for activity of mules (pushers). Less often self-propelled scraper is ganged up (build­ing-block designed) so, that it has no drive truck (fig. 3., d). Trailed scrapers (fig. 3., a) are step-by-step displaced by self-propelled. Still they find application at the very hard relief of terrain, poor road condi­tions, and in a wet climate at the distance of transportation up to 400 - 500 m.

Fig. 3. The schemes of scrapers (the digits demonstrate approximately the distribution of the scraper weight with a spring bucket (scoop) in % per an axle): a - trailed; b and c - semi-trailed to bi-axle and single-axle wheel drive trucks; d- self-propelled

The scrapers are widely used at the construction of roads cloth, grading building sites, at earth excavations in mild, mean, and solid (coarse, robust), but without large inclusions soils. Especially they are used where the soil is displaced to underlying marks, where transporting distance makes 0.8 - 1.5 km, and the climate is dry enough. However, they are used even if the distance of transportation makes up to two and more kilometers. Especially if it is possible for the scrapers to get to a road with the cover (coating) where they can gain speed up to 60 km/h.

When scrapers are equipped with reinforced scoops, they are ap­plied to clean rocky and frozen grounds. These grounds have to be pre­viously loosened by rippers. In the case of reinforced scoops scrapers are also applied to transport the soil on impassibility or ground roads at the distances from 0.15 up to 15 km with its decentralized dumping all over a considerable area.

The scraper works as follows. Having approached drawn up to a place of scraping the soil, the scraper-driver changes the drive truck over to the first gear and simultaneously drops the bucket (scoop), up­lifting the shutter. The scoop is cut in into the soil by its own dead weight, efforts of the hydraulic cylinder (when hydraulically controlled) and the thrust force of a tractor (trailed scraper) or the thrust force of one - three mules (pushers) (self-propelled). In filling time the scraper-driver watches the filling of the scoop and adjusts the depth of cutting in accordance with the engine load. Usually the scoop puts deeper fast at the maximum depth, and then step-by-step mounts to back up the thrust force at some more or less constant most effective level. The path of filling depends on a scraper capacity, ground hardness and tractive force and varies from 8 up to 35 m.

When the soil ceases to come into the scoop because of impossi­bility of a diminished depth of cutting to penetrate through the soil bulk in the bucket any more, the scraperist starts lifting the scoop, closing the shutter. He engages the second or the third speed gear and moves to the place of unloading. For the majority of scrapers the unloading is made during the motion forward. Depending on a scraper capacity the depth of a discharged layer makes 0.20-0.60 m. It is adjusted by lowering or lifting the shutter. The path of the unloading reaches 15-40 m.

The process of activity of a scraper goes on continuously. Only scrapers with the back unloading make stops for dumping if it is made downhill from a bank.

The scrapers work in-groups of 10 - 30 machines when there is large scope of work. They move by a self-contained line that usually has the orthogonal view with truncated comers in the horizontal plane.

The lower limit of the expedient transporting distance for wheel drive trucks makes 150 - 200 m. As at short distances they cannot com­pletely use the speed, they should be used on small volume operations at availability of trailed scrapers and bi-axle drive trucks that have been not engaged at other works.

Semi-trailed (self-propelled) scrapers are produced with the ca­pacity from 6 up to 45 m³. At the capacity of 6 - 10m^J they are more often applied with single-axle drive trucks at a power of 150 to 270 hp. They are used for small volume operations, at the distances of transpor­tation from 150 up to 2,500 m and conditions requiring a high maneu­verability (for example, filling sluice spans, small trenches, pouring (dumping) out from the head of rather low-level height banks, and at the hard relief conditions).

At the capacity from 12 up to 45 m³ and good road conditions semi-trailed scrapers are suitable to use with single-axle wheel drive trucks at a power of 300 to 1,600 hp. Less often, at the distance of trans­portation more than 2.0 km they are used with bi-axle drive trucks at the same power.

The maximum rise which is overcome by a laden semi-trailed scraper on the first gear of a wheel drive truck makes 30 — 35 %. The most maneuverable and fast-running earth-moving transport machines are semi-trailed scrapers with single-axle drive trucks. However, their disadvantage is that only 52 - 55% of the laden machine weight is transmitted to the driving axle of a drive truck. That considerably re­duces their thrust capabilities and causes usually to resort at filling them to the help of 2 - 3 mules. These mules can be either bi-axle drive trucks, or crawler tractors with a special buffer equipped with the damp­ing device or in the last resort with the customary blade of a bulldozer, fastened upon a buffer gear of a scraper. The tractive force of bi-axle wheel drive trucks is used even less. For them, only 37 - 38 % of the laden machine weight is transmitted to the driving axle.

Until recently, their advantage was the higher transport speed (up to 70 km/h). However, a new saddle connection damping device of a single-axle drive truck with a scraper has allowed to make even their speeds. The installation of the second diesel engine on the rear wheels of a scraper has allowed to increase the speed of a laden scraper on rises and has enabled it to overcome the rises up to 35 %, but, naturally, could not replace even 2 mules. Besides the twin-engined machines have the operational readiness coefficient less by 3 - 4 %.

The filling of a scoop depends on physical-mechanical properties of the soil. If the scoop is constructed correctly its filling with the soil can be parted into 3 phases (fig. 4.).

The stepped form of a scraper knife with the outstanding forward middle section is shown in fig. 5. It is made so that during putting up a scoop the cutting depth (thickness of shaving) would be the same so long as possible, that is indispensable for pushing through the soil in a scoop, and so that it would be augmented faster at a scoop putting deeper.

Fig. 4. The schemes of a scoop filling with the soil: a — for plastic soils; b — for loose (free-flowing) soils; I — the first phase; II — the second phase; III — the third phase

Apart from a straight line (seldom used) and stepped form, the semicircular form of a scraper knife can be used (fig.6).

Fig. 5. The stepped form of a scraper knife

Fig. 6. The semicircular shape of a scraper knife

Besides the basic knife there can be installed replaceable knives attached to the lower part of the scoop side walls.

Score: 30

Ex.6. Find in the text English equivalents to the following Ukrainian words and word-combinations:

приводити до руху, поступове скобління землі, модель з призначеною для розвантажування задньою частиною, ущільнення землі, відкидна засувка, шар землі, за однин раз, трактор-тягач з однією / двома осями, розвивати швидкість, розпушувач, непрохідні дороги, зубчата передача, власна вага, занурення ковша, встановлювати глибину, потужність скреперу, сила тяги, припиняти поступати (в), зменшена глибина, проникати, ґрунтова маса, прямокутна форма, шлюзові об’єми, низькі насипи, провідна вісь, зменшувати тягову спроможність, призводити до звертання по допомогу, демпфер, буфер, ступінчаста форма ножу, товщина зрізання, необхідний, напівкругла форма ножу.

Score: 5

Ex.7. а) Find in the text 4 word-combinations in bold type. Translate them in writing consulting the polytechnic dictionary.

Notes: Основа синтаксичної будови мови– речення і слово­сполучення.

Словосполучення, яке містить в собі блок інформації, виражає граматичну та лексичну залежність одного слова від іншого.

Мінімальний обсяг словосполучення – два повнозначних слова, які об’єднуються підрядним зв’язком без прийменника (синтетичне словосполучення): experimental equipment, spaceship flight; або за допомогою прийменника (аналітичне словосполучен­ня): to differ in size, two by two.

Між компонентами словосполучення можуть здійснюватися різні за характером відношення: означальні (a solid body), об’єктні або додаткові (to found a theory, to solve a problem), обставинні (explored in accordance with the program).

Словосполучення прийнято класифікувати за головним членом словосполучення, яким може бути будь-яка повнозначна частина мови: дієслово (V), іменник (S), прикметник (A), займенник (P), числівник (N), прислівник (Adv). Залежним членом словосполучення може бути також тільки повнозначна частина мови: іменник, прикметник, займенник, числівник, неособова форма дієслова.

Словосполучення, які виражають складні поняття (на відміну від слів, що виражають прості поняття), є засобом номінації (тобто називання) дій, предметів, якостей, які перебувають у певних співвідношеннях з предметами, явищами, властивостями тощо.

Словосполучення можуть вичленовуватися із тексту або служити “будівельним матеріалом” для речення, тобто існувати незалежно від нього. Так, у галузевих словниках звичайно подаються, поряд із словами-термінами і словосполучення-терміни, наприклад: strength of materials (опір матеріалів), compression fracture (руйнування при стиску), fineness modulus method of proportioning (підбір складу бетону з урахуванням крупності).

За своєю синтаксичною структурою словосполучення можуть бути простими, ускладненими, складними і комбінованими.

Словосполучення-терміни утворюються в результаті лексичного та граматичного розширення повнозначної частини мови з певною валентністю, що породжує адекватні структури для ущільнення інформаційної цінності.

Словосполучення-терміни підлягають загальним закономірностям побудови та функціонування словосполучень і утворюються на основі елементарних структурних схем (безприйменникових і прийменникових (коли прийменник позначити р – preposition)), наприклад:

A + S – digital input (цифровий пристрій для даних),

S₁ + S₂ – translation circuit (схема перекладу),

S₁ + p + S₂ – law of averages (закон великих чисел),

S + p + N – basis of ten (основа десять),

A + p + A – black on write (“чорне по білому”).

b) Arrange the following word-combinations according to their structural scheme. Translate them.

	V + S		to construct correctly
	S1 + S2		the horizontal plane
	S1 + p + S2		indispensable for pushing
	V1 + V2		small volume operations
	V + p + S		to adjust the depth
	N + p + N		the first gear
	A + S		so long
	A + p + S		a power of 150
	S + Adv		a place of scraping
	N + S		to penetrate through the soil
	S + p + N		control system
	A + S1 + S2		these mules
	P + S		to enable to overcome
	Adv + Adv		the motion forward
	V + Adv		step-by-step

c) Explain the translation of the following terms and word-combinations:

drive truck, unloading back, crawler tractor, scraper bowl, coupling device, buffer unit, pull-type scraper, trailed scraper, semi-trailed scraper, self-propelled type scraper, two-wheeled scraper, wheeled bucket, hinged type shutter, semitrailer scoop, single-axle wheel drive truck, bi-axle wheel drive truck, building-block design, reinforced scoop, hydraulically controlled cylinder, self-contained line, low-level height bank, fast-running earth-moving transport machines, level-by-level.

Score: 15

Ex.8. Arrange the following words and word-combinations in pairs of synonyms:

pusher, the soil bulk, bucket, earth, coat, diminished, to put in motion, laden, readiness, to stop, soil, necessary, shipment, shutter, mule, bowl, to shear, reduced, robust soil, cover, loaded, preparedness, indispensable, to cease, to shave, loading, to set in motion, the soil bank, coarse soil, flap.

Score: 15

Ex.9. Fill in the blanks with the following words and expressions. Translate the sentences.

still, depends on, equipped with, in accordance with, apart from, at a time, only, however, less often, forward, except for, besides, as, because of.

1. Scrapers are also used for grading the ground and for its compaction … models with an unloading back.

2. The scraper bowl removes a strip of earth … .

3. … self-propelled scraper is ganged up so, that it has no drive truck.

4. … trailed scrapers find application at the very hard relief of terrain, poor road conditions and in a wet climate at the distance of transportation up to 400-500 m.

5. …, the scrapers are used even if the distance of transportation makes up to two and more kilometers.

6. When scrapers are … reinforced scoops they are applied to clean rocky and frozen grounds.

7. In filling time the scraper-driver watches the filling of the scoop and adjusts the depths of cutting ... the engine load.

8. When the soil ceases to come into the scoop … impossibility of a diminished depth of cutting to penetrate through the soil bulk in the bucket any more, the scraperist starts lifting the scoop, closing the shutter.

9. For the majority of scrapers the unloading is made during the motion … .

10. … scraper with the back unloading make stops for dumping if it is made downhill from a bank.

11. … at short distances wheel drive trucks cannot completely use the speed.

12. The filling of a scoop … physical-mechanical properties of the soil.

13. … a straight line and stepped form, the semicircular form of a scraper knife can be used.

14. … the basic knife there can be installed replaceable knives.

Score: 14

Ex.10. Form 9 sentences combining suitable parts of the table.

	A scraper	consists of	with a crawler tractor.
	Scrapers	are step-by-step displaced	a semitrailer scoop for a single / bi-axle wheel drive truck, control system, coupling and buffer devices for activity of mules.
	The trailed scraper	are used	correctly its filling with the soil can be parted into 3 phases.
	The pull-type scraper	consist of	a scraper capacity, ground hardness and tractive force.
	Self-propelled scrapers	set in	for level-by-level shearing off the soil, transporting and unloading.
	Trailed scrapers	is constructed	continuously.
	The path of filling	goes on	motion by its own engine or a drive truck.
	The process of activity of a scraper	works	a wheeled bucket, equipped with a hinged type shutter, a control system of a bucket, a coupling device and a buffer unit.
	If the scoop	depends on	by self-propelled.

Score: 9

Ex.11. Find out all the numerals in the text. Read and translate them aloud.

Notes: В англійських числівниках кожні три порядки відділяються комою ( 1,000 – a thousand; 1,000,000 – a million).

У десяткових дробах ціла частина відокремлюється від дробової не комою, а крапкою (point). Кожна цифра як цілої, так і дробової частини десяткового дробу читається окремо.

Нуль читається nought.

41.306 – four one point three nought six.

Якщо ціла частина дорівнює нулю, то число можна прочитати двома способами:

0.785 – nought point seven eight five, або

point seven eight five.

Якщо після десяткового дробу, ціла частина якого дорівнює нулю, стоїть іменник, він вживається в однині з прийменником of. Але якщо ціла частина не нуль, то іменник вживається в множині без прийменника.

0.26 m point two six of a metre (0,26 метра).

2.34 m two point three four metres (2,34 метрів).

Nought , zero, oh, nil, nothing.

Цифра «0» у British English передається словом nought, а в American English – zero. Коли у числі кожна цифра вимовляється окремо, «0» часто читається oh (як буква -О-), наприклад:

My account number is 41306 (four one three oh six).

Для позначення температури і в ВЕ, і в АЕ вживається слово zero, наприклад: Zero degrees Celsius is thirty-two degrees Fahrenheit.

Нульовий рахунок у спортивних іграх передається словом nil y BE та zero, або nothing в AE.

And the score at halt-time is: Italy – three, Spain – nil. (three – nil 3:0 ).

Score: 5

Ex.12. Fill in the gaps with the words and word-combinations given below and translate the sentences.

1. Scrapers can be of the _____ , ______ and _______ type.

2. Scraper is attached to a tractor with a ________ .

3. The scrapers are widely used at the construction of _______ , grading building sites, at earth excavations in mild, mean and solid but without large ______ soils.

4. If scrapers are equipped with ______ they are also applied to transport the soil on impassability or ground roads at the distances from 0.15 up to 15 km with its decentralized ______ all over a considerable area.

5. The scoop is cut in into the soil by its own ______ , efforts of the hydraulic cylinder and the ________ of a tractor or one - three mules.

6. After filling procedure the scraperist engages the second or the third speed _____ and moves to the place of unloading.

7. Depending on a ________ the depth of a discharged layer makes 0.20 – 0.60 m.

8. The most _______ and _______ earth-moving transport machines are semi-trailed scrapers with single-axle drive trucks.

9. These mules can be either bi-axle drive trucks or _____ tractors with a special ______ equipped with the damping device or with the customary blade of a bulldozer.

10. The twin-engined machines have operational _________ less by 3-4%.

dumping, gear, fast-running, semi-trailed, inclusions, thrust force, buffer, trailed, coupling device, crawler, self-propelled, reinforced scoops, readiness coefficient, roads cloth, dead weight, scraper capacity, maneuverable.

Score: 10

Ex.13. Read the following and decide whether the statements are true or false. Correct them if necessary.

1. The scraper is an earth-moving machine with a knife.

2. They can be of the different types: the pull-type, semi-trailed and self-propelled type.

3. At a place of scraping the soil the scraper-driver changes the drive truck over to the third gear and simultaneously drops the bucket, uplifting the shutter.

4. The scrapers work in-groups of 10-30 machines when there is large scope of work.

5. The lower limit of the expedient transporting distance for wheel drive truck makes more than 2.0 km.

6. At the capacity of 6-10 m³ semi-trailed scrapers are applied with single-axle drive trucks at a power of 150 to 270 hp.

7. They are used for small volume operations, at the distance of transportation from 150 to 2,500 m and at the good road conditions.

8. At the capacity of 12-45 m³ and poor road conditions semi-trailed scrapers are suitable to use with single-axle wheel drive trucks at a power of 300 to 1,600 hp.

9. Only 37-38% of the laden machine weight is transmitted to the driving axle of bi-axle wheel drive trucks.

10. A new saddle connection damping device of a single-axle drive truck with a scraper has allowed to make even their speeds.

11. The installation of the second diesel engine on the rear wheels of a scraper has allowed to decrease the speed of a laden scraper on rises.

12. During putting up a scoop the cutting depth would be the same if the stepped form of a scraper knife is used.

Score: 12

Ex.14. Match each word on the left with the correct definition on the right.

1.	wheel	a)	an energy heart of a vehicle; a mechanism designed to convert energy, especially heat energy into mechanical work.
2.	knife	b)	a terrain surface form, local topography.
3.	road	c)	a solid disc, that is mounted on a shaft about which it can turn, as in vehicles and machines.
4.	inclusion	d)	anything that resembles a bowl in action, such as the bucket on a dredge.
5.	frozen	e)	an open way, usually surfaced with asphalt or concrete, providing passage from one place to another.
6.	reinforced	f)	to unload, empty (objects or material) out of a container.
7.	scoop	g)	a cutting instrument consisting of a pointed blade of metal.
8.	engine	h)	a solid fragment in the soil.
9.	to dump	i)	the state of being frozen.
10.	relief	j)	strengthened, forced, armoured.

Score: 10

Ex.15. a) Find the equivalents to the following words and word-combinations:

	drive truck		висока маневреність
	grading		прилад зв’язку
	pull-type / trailed		навантаження на двигун
	semi-trailed		мерзлі грунти
	self-propelled type		елементи великих мас
	wheeled bucket		вантажівка-тягач
	coupling device		самохідний тип
	roads cloth		напівпричіпний тип
	inclusions		градирування
	frozen grounds		колісний черпак
	reinforced scoop		розвантажування
	engine load		причіпний тип
	high maneuverability		армований ківш
	dumping		полотно дороги
	hard relief conditions		умови складного рельєфу

b) Use them in sentences of your own.

Score: 15

Ex.16. Ask questions to get these answers.

1. A scraper.

2. A semitrailer scoop, control system, coupling and buffer devices.

3. Where the soil is displaced to underlying marks, where transporting

distance makes 0.8-1.5 km and the climate is dry enough.

4. By rippers.

5. The first gear.

6. The second or the third speed gear.

7. A high maneuverability.

8. Owing to the stepped form of a scraper knife.

Score: 8

Ex.17. Look at Fig. 3., name a, b, c, d.

Score: 2

Ex.18. Look at Fig. 4., name a, b and describe the figure.

Score: 5

Ex.19. Answer the following questions on the text:

1. How can an earth-moving machine be set into motion?

2. How many types of scrapers can you name? What are they?

3. What is the difference between trailed, semi-trailed and self-propelled types of scrapers?

4. What is the main field of using scrapers?

5. What is the condition under which a scraper can work on rocky and frozen grounds?

6. What is the procedure of operation carried out by a scraper?

7. How does the capacity of a scraper influence the working mode of a scraper?

8. What is the advantage of semi-trailed scrapers with single-axle drive trucks?

9. When is it necessary to use the help of 2-3 mules? What are these mules?

10. What improvements are used for single-axle drive truck to make its technical characteristics better?

11. How is the scraper scoop constructed? How does it function?

Score: 11

Ex.20. Translate the sentences into English using your active vocabulary of Ex.4.

1. Скрепери – машини для земельних робіт, які приводяться до руху власними двигунами, або вантажівкою-тягачем.

2. Скрепери створені для поступового скобління землі, її транспортування та розвантажування.

3. Вони діляться на причіпний, напівпричіпний та самохідний типи.

4. Причіпний скрепер працює з гусеничним трактором.

5. Він складається з колісного черпака (ковша чи лопати скреперу), оснащеного відкидною засувкою, системою керування, приладом зв’язку та буфером.

6. Напівпричіпні скрепери переважно застосовуються з одноосьовими (інколи з подвійною віссю) вантажними колісними тягачами.

7. Скрепери використовуються також при будівництві доріг, гради­ру­ванні площин з будівлями, ущільненні ґрунту, а також при його транспортуванні та розвантажуванні.

8. Скрепери широко використовуються на ґрунтах різного типу, проте, без великої кількості елементів великих мас.

9. Коли скрепери оснащені армованим ковшем, вони можуть застосовуватися для очищення скелястих та мерзлих ґрунтів.

10. Під час занурення ковша, водій скреперу спостерігає за ковшем та пристосовує глибину копання відповідно до навантаження на двигун.

11. Напівпричіпні (самохідні) скрепери використовуються при умовах наявності високої маневреності (для заповнення шлюзових об’ємів, маленьких траншей, розвантажування згори доволі низьких насипів та при умовах складного рельєфу).

Score: 11

Ex.21. Be ready to speak about the scraper as an earth-moving transport machine.

Score: 10

Ex.22. Read Text 2.1. in 5 minutes and give a heading to each paragraph.