11 1
Read the words. Point out modal verbs: a) equip; b) permit; c) seem; d) happen; e) should; f) might; g) appear; h) prove; i) mention; j) would; k) must; 1) set; m) make; n) get;
o) can; p) could; q) enable.
12 4
Read the word-combinations and point out Infinitives and Participles:
a) the most common being positive; b) the effect being neglected;
c) calculated the content to be; d) found this to be true; e) the possibility of being converted; f) can write the heat energy to be, as follows; g) with all the adverse influence acting jointly; h) proofs of his having been wrong; i) with summation substituted for; j) with the oxygen normally available; k) alcohol is said to be a suitable medium; 1) conceived it as being a property of; m) two members have been found by them to contain.
13 5
Read the sentences and define in each of them the meaning of the word “fire”.
1. The regulator generates a signal which changes the firing angle of the thyristors. 2. He is between two fires and does not see the way out.
3. Dry wood soon catches fire. 4. One fire drives out another. 5. It is hardly likely that anyone will want to draw the fire of the newspapers again. 6. If you hang fire now, you will never get so good a chance
again. 7. Well, fire away! What made you do such a thing? 8. Many workers of this firm were fired and increased the army of jobless.
Translate at sight the following sentences. Mind the translation of Passive Voice.
1. An electric field will be produced between the electrodes. 2. Current is passed between the solenoid. 3. The early convention as to the direction of current has never been changed. 4. The machine is repaired.
5. The atom may be regarded as the smallest particle of an element.
6. The temperature was being increased. 7. If you were asked this question, what would your answer be? 8. These laws are simple and can be relied on. 9. The chemical action will cease immediately if the connecting wire is removed.
17 4
In the following sentences transform Active Voice into Passive. Model. We showed the engineers the test results. — The test results were shown to the engineers. The engineers were shown the test results.
1. We showed them some of the latest models. 2. They gave the workers new tools. 3. They are developing a new method. 4. The firm has sent us the price list. 5. A compressed air mechanism moves the plate.
18 20
Home exercise. Look through the text and find equivalents to the following Russian words and word-combinations.
Электроприводы буксирных лебедок, буксировка на гибкой связи (1); неустановившееся движение (1); учитывая оптимальные соотношения скоростей (1); на средней скорости (1); по схеме двойного питания от сети (1); тиристорный преобразователь частоты с непосредственной связью (2); нормальная скорость выбирания троса (3); расчетная мощность (4); режим 30 минут (4); импульсное включение (4).
Electric Drives of Towing Winches
4. Flexible-link towing is a physical process involving unsteady motion of inertia masses interconnected by a flexible element. Reliability of towing depends on selection of an optimum length of the towline and on minimizing the towline, overloads under various conditions. Non-automatic towing winches with a pull of 120 kN and above may be used with three-speed a-c cage motors controlled by means of magnetic controllers. Taking account of the optimum speed ratio of the winches for towlines 37.5 to 48.5 mm in diameter use may be made of three-speed motors with a speed ratio of 1:2:4, developing a rated power and a rated pull at the medium speed; the motors are controllers. Winches with a 56 to 65 mm diameter towline may be driven by cage motors with a speed ratio of 1:3, producing the rated pull at the medium speed. To obtain low rotation speeds in order to limit the load on the towline these motors must be connected in a dual supply circuit:
2. The motors must be supplied from the supply mains when running at the rated or high speed and from a directly-coupled thyristor converter, when running at low speeds. To ensure the required power two motors may be connected to one shaft. The maximum power rating of such systems is 140 kW, which enables them to be used for the largest winches with a pull of up to 650 kN. 3. The power rating of the motor to be used in the winches is selected to suit the pull required to heave in the tow-
