По источнику подачи рабочей жидкости гидроприводы могут быть насосным, магистральными и аккумуляторными.
Cargo Handling Equipment
There are the various items of machinery and equipment found outside of the machinery space. These include deck machinery such as mooring equipment, anchor handling equipment, cargo handling equipment and hatch covers. Other items include lifeboats and life rafts, emergency equipment, watertight doors, stabilisers and bow thrusters.
The operations of mooring, cargo handling and anchor handling all involve controlled pulls or lifts using chain cables, wire or hemp ropes. The drive force and control arrangements adopted will influence the operations.
Two forms of power are currently in use: hydraulic and electric. Each method has its advantages and disadvantages for particular duties or locations.
Cargo winches are used with the various derrick systems arranged for cargo handling. The unit is rated according to the safe working load to be lifted and usually has a double-speed provision when working at half load.
In the cargo winch, spur reduction gearing transfers the motor drive to the barrel shaft. A warp end may be fitted for operating the derrick topping lift. Manually operated band brakes may be fitted and the drive motor will have a brake arranged to fail-safe, i.e. it will hold the load if power fails or the machine is stopped.
A derrick rig is known as 'union purchase'. One derrick is positioned over the quayside and the other almost vertically over the hold. Topping wires fix the height of the derricks and stays to the deck may be used to prevent fore and aft movement. Cargo handling wires run from two winches and join at the hook. A combination of movements from the two winches enables lifting, transfer and lowering of the cargo. This is only one of several possible derrick arrangements or rigs. Although being very popular for many years, it requires considerable crew time to set up and considerable manpower for operation.
Cranes have replaced derricks on many modern ships, cranes are positioned between the holds often on a platform which can be rotated through 360°. The deck crane provides an immediately operational unit requiring only one man to operate it. Double gearing is a feature of most designs, providing a higher speed at lighter loads. Various types of crane exist for particular duties, for example a general duties crane using a hook and a grabbing crane for use with bulk cargoes. A general cargo crane has three separate drives that provide the principal movements: a hoisting motor for lifting the load, a motor for raising or lowering the jib and a slewing motor for rotating the crane. The operator's cab is designed to provide clear views of all the cargo working area so that the crane operator can function alone. The crane is usually mounted on a pedestal to offer adequate visibility to the operator.
Maintenance.All deck machinery is exposed to the most severe aspects of the elements. Total enclosure of all working parts is usual with splash lubrication for gearing. The various bearings on the shafts will be greased by pressure grease points. Open gears and clutches are lubricated with open gear compound. Particular maintenance tasks will be associated with the type of motor drive employed.
Exercise 3.Answer the following questions:
1. What is this text about? 2. What cargo handling equipment do you know? 3. What cargo handling equipment is mentioned in the text? 4. What mooring or anchor handling equipment is on board of a ship? 5. What should be done for keeping all mentioned equipment in good condition?
Exercise 4. Give equivalents:
· in Russian: slew gear, to slacken, pedestal, power pack, cable lifter, windlass, failure, jib, to warp around, tension, spurling pipe, reduction gear, cable locker, watertight doors, take-off, pump suction head, stowage rack, flush, roller, hatch cover, at half load, clutch;
· in English: якорное устройство, поворотный механизм, двойная зубчатая передача, опорная плита, зубец или подпорка, загрузочно-разгрузочное оборудование, крышка люка или люковое закрытие, брызги, стреловое устройство, грузовой захват, кнехт, заранее устанавливать, ослаблять, брашпиль, пристань, выбиваться, блок питания, клин или крепительная планка, однопроводной, блокировать, находящийся под напряжением, незначительный, система среднего давления, лебедка, транспортеры, подъемные механизмы, стрелы, аппарели или рампы, люковые закрытия.
Exercise 5. Read the text carefully and find the following words and expressions in English.
кнехт, зубец или подпора, подъем, брашпиль, основной, закреплять,
обматывать, заранее устанавливать, захватывать,
натягивать, ослаблять, вертикальная ось, вращаться,
кулачковая муфта, бочка или барабан
Mooring equipment
Winches with various arrangements of barrels are the usual mooring equipment used on board ships. The winch barrel or drum is used for hauling in or letting out the wires or ropes which will fasten the ship to the shore. The warp end is used when moving the ship using ropes or wires fastened to bollards ashore and wrapped around the warp end of the winch.
The motor drive of mooring winch is passed through a spur gear transmission, a clutch and thus to the drum and warp end. A substantial frame supports the assembly and a band brake is used to hold the drum when required. The control arrangements for the drive motor permit forward or reverse rotation together with a selection of speeds during operation. Modern mooring winches are arranged as automatic self-tensioning units. The flow of the tides or changes in draught due to cargo operations may result in tensioning or slackening of mooring wires. To avoid constant attention to the mooring wires the automatic self-tensioning arrangement provides for paying out (releasing) or recovering wire when a pre-set tension is not present. (900)
Anchor handling equipment
The windlass is the usual anchor handling device where one machine may be used to handle both anchors. Particularly on larger vessels the split windlass is employed, its construction means that one machine is used for each anchor. The rotating units consist of a cable lifter with shaped snugs to grip the anchor cable, a mooring drum for paying out or letting go of mooring wires and a warp end for warping duties. Each of these units may be separately engaged or disengaged by means of a dog clutch, although the warp end is often driven in association with the mooring drum. A spur gear assembly transmits the motor drive to the shaft where the various dog clutches enable the power take-off. Separate band brakes are fitted to hold the cable lifter and the mooring drum when the power is switched off. The cable lifter unit is mounted so as to raise and lower the cable from the spurling pipe, which is at the top and centre of the chain or cable locker. Details of the snugs used to grip the cable and of the band brake can be seen. Anchor capstans are used in some installations where the cable lifter rotates about a vertical axis. Only the cable lifter unit is located on deck, the driving machinery being on the deck below. A warping end or barrel may be driven by the same unit and is positioned near the cable lifter. (1,000)
Exercise 6. Translate the dialogues and then make up your own one.
A: All the tow lines are made fast.
B: O.K. Dead slow ahead! On the tugs! Commence towing! (several minutes later)
A: Is the berth fitted with fenders?
B: Yes, the berth is fitted with fenders.
A: Is there a 10-ton crane on that berth? We’ve got some heavy lifts.
B: There are two 15-ton cranes on that berth.
A: That’s good.
***
A: As far as I know the type of the “Ro-Ro” depends upon how the ramp is fixed into position.
B: That’s right but only to some degree. You see, we have an angled hydraulically operated stern ramp putting into position when the height of the berth is between 2.0 and 3.5 m.
A: Do you mean that the height of berth No3 doesn’t meet these requirements?
B: No, it doesn’t especially in high water. The height of the berth then will be not more than 20 cm and you can neither load nor discharge the vessel under such circumstances.
***
B: Почему грузчики приостановили выгрузку моего судна?
A: Дело в том, что для выгрузки этого груза им требуется специальное грузовое устройство. Его привезут с соседнего причала через 20 минут.
***
A: Какой привод у Вашей аппарели?
B: У нас электрический привод, однако на некоторых судах он может быть и гидравлическим.
***
A: Где будет выгружаться наше судно?
B: У причала №8, так как он оборудован подвижной приливной аппарелью.
***
A: Как распределяется груз на вашем судне?
B: Наше судно «ро-ро» трехпалубное. Для груза на судне есть внутренние аппарели и подвижные переборки.
***
A: Есть ли на Вашем судне подруливающее устройство?
B: Да, у нас есть носовое подруливающее устройство.
A: Я думаю, что это облегчит Вам маневрирование.
B: Да, конечно, я собираюсь заходить в порт без буксира.
Exercise 7. Choose the right variant.
Table A.
| 1. роульс | a) shaft | c) roller |
| b) cylinder | d) coaming | |
| 2. стойка | a) stationary base | c) basin |
| b) wall | d) standing | |
| 3. шпиль | a) heel | c) capstan |
| b) windilass | d) stud | |
| 4. стопор | a) stupor | c) span |
| b) axe | d) lock or spin | |
| 5. якорный клюз | a) spurling pipe | c) towing pipe |
| b) anchor hawsepipe | d) stern hawsepipe | |
| 6. причальный конец | a) berth line | c) mooring line |
| b) tie-down line | d) anchor line | |
| 7. кранцы | a) cranes | c) fenders |
| b) rings | d) ties | |
| 8. багор | a) hook | c) thrust |
| b) hitch | d) stud | |
| 9. скоба | a) clean | c) chain shackle |
| b) cage | d) cleat | |
| 10. кронштейн | a) stud | c) tie |
| b) strut | d) tray |
Table B.
| 1. idler conveyor | a) парный транспортер | c) конвейер |
| b) вспомогательный транспортер | d) холостой ход | |
| 2. kedge | a) клетка | c) безопасный край |
| b) танкер | d) стоп-анкера | |
| 3. anchoring line | a) швартовочный якорь | c) причальный конец |
| b) якорный канат | d) буксировочный буй | |
| 4. tie-down ring | a) натяжное кольцо | c) швартовочное кольцо |
| b) гидравлическое соединение | d) стесненное кольцо | |
| 5. lifting gear | a) подъемное устройство | c) поднимающая опора |
| b) лифтинговая передача | d) подъемная шестерня | |
| 6. mooring bollard | a) буксирный кнехт | c) швартовочный кнехт |
| b) переносная тумба | d) швартовочный узел | |
| 7. derrick rig | a) кольцо стрелы | c) такелаж крана |
| b) стреловое устройство | d) оснастка стрелы |
Exercise 8. Look through the text and then decide which statement is TRUE/FALSE.
· To seal off the holds only watertight doors are used.
· The term “hand-operated” means “manually controlled”.
· Any hatch cover works without a power source.
· Maintenance for automated hatch covers is negligible.
· Hatch covers are the basic units of cargo handling equipment.
Hatch covers
Hatch covers are used to close off the hatch opening and make it watertight. Steel hatch covers, comprising a number of linked steel covers, are now fitted universally. Various designs exist for particular applications, but most offer simple and quick opening and closing, which speed up the cargo handling operation. The hatch covers are arranged to move on rollers along a track on top of the hatch coaming. The individual covers are linked together by chains and ride up and tip onto a stowage rack at the hatch end. A hydraulic power unit, operated from a control box at the hatch end, is used to open and close the hatch cover. It is possible to open and close the covers with a single wire pull from a crane or winch. Watertigtitness of the closed covers is achieved by pulling them down on to a compressible jointing strip. This is done by the use of cleats which may be hand-operated or automatically engaged as the hatch closes. Hatch covers below the weather decks are arranged flush with the deck. In the arrangement shown a self-contained hydraulic power pack with reservoir pump and motor is mounted into a pair of hatch covers. This power pack serves the operating cylinder for the pair of covers. Control is from a nearby point and hydraulic piping is reduced to a minimum. Maintenance requirements for this equipment are usually minimal but regular inspection and servicing should be undertaken. Most hatch covers can, if necessary, be removed manually. (1,200)
Exercise 9. Translate into Russian.
Part A. Hydraulic systems.The open-loop circuit takes oil from the tank and pumps it into the hydraulic motor. A control valve is positioned in parallel with the motor. When it is open the motor is stationary, while when it is closed the motor will operate. The exhaust oil returns to the tank. This method can provide stepless control, i.e. smooth changes in motor speed. The live-line circuit, on the contrary, maintains a high pressure from which the control valve draws pressurized oil to the hydraulic motor (in series with it), as and when required. In the closed-loop circuit the exhaust oil is returned direct to the pump suction. Since the oil does not enter an open tank, the system is considered closed. Low-pressure systems use the open-loop circuit and are simple in design as well as reliable. The equipment is large, inefficient in operation and overheats after prolonged use. Medium-pressure systems are favoured for marine applications, using either the open or closed circuit. Smaller installations are of the open-loop type. Where considerable amounts of hydraulic machinery are fitted the live-circuit, supplied by a centralised hydraulic power system, would be most economical.
Part B.Electrical operation.Early installations used d.c. supply with resistances in series to provide speed control. This inefficient power-wasting method was one possibility with d.c., but a better method was the use of Ward Leonard control. The high cost of all the equipment involved in Ward Leonard control and its maintenance is a considerable disadvantage. Machines operated on an a.c. supply require a means of speed control with either pole-changing or slip-ring motors being used. Slip-ring motors require low starting currents but waste power at less than full speed and require regular maintenance. Pole-changing motors are of squirrel cage construction, providing for perhaps three different speeds. They require large starting currents, although maintenance is negligible.
Apart from the advantages and disadvantages for each of the drive and control methods, all electric drives have difficulty with heavy continuous overloads. Each system has its advocates and careful design and choice of associated equipment can provide a satisfactory installation.
Exercise 10. Translate into English.
1. Электрический привод - это электромеханическая система для приведения в движение механизмов рабочих машин и управления этим движением.
2. Гидропривод представляет собой своего рода «гидравлическую вставку» между приводным двигателем и нагрузкой (машиной или механизмом) и выполняет те же функции, что и механическая передача (редуктор, ремённая передача, кривошипно-шатунный механизм и т. д.).
3. В гидроприводе с замкнутой схемой циркуляции рабочая жидкость от него возвращается во всасывающую гидролинию насоса, кнедостаткам следует отнести плохие условия для охлаждения рабочей жидкости и необходимость спускать из гидросистемы рабочую жидкость при замене или ремонте гидроаппаратуры.
Рабочая жидкость постоянно сообщается с гидробаком или атмосферой в гидроприводе с разомкнутой системой циркуляции, достоинства такой схемы являются хорошие условия для охлаждения и очистки рабочей жидкости, а недостатком можно считать громоздкость и большую массу.
COMPREHENSIVE READING
Text A. Stern and Bow Doors
Ro-ro vessels may be fitted with stern doors of the hinge down or hinge up type which if large are articulated. Bow doors are either of the visor type or of the side hinged type (‘barn door’ type). These are situated above the freeboard deck and where the bow doors lead to a complete or long forward enclosed superstructure Lloyd’s require an inner door to be fitted which is part of the collision bulkhead. This would also be in keeping with the SOLAS requirements for passenger ships where the collision bulkhead is to be extended weathertight (стойкий против атмосферных воздействий) to the deck next above the bulkhead deck, but need not be fitted directly above that bulkhead. A sloping weathertight vehicle ramp may be fitted in some ships to form the collision bulkhead above the freeboard deck and the inner door is omitted. This ramp may extend forward of the specified limit for the collision bulkhead above a height of more than 2.3m above the bulkhead deck, i.e. above the height of a conventional tween deck space. Stern and bow door strengths are equivalent to the strength of the surrounding structure and where they give access to enclosed superstructures they are required to close weathertight. Stern doors and bow visors can be mechanically raised and lowered with wire rope and purchase arrangements but in general they and the side hinged bow doors are hydraulically opened and closed. These weathertight doors are gasketted and cleated.
Text B. Ramps
Ro-Ro ships fitted with ramps usually have a stern ramp, but some vessels fitted with bow doors may also have a bow ramp which doubles as the inner weathertight door (see above) and is lowered onto a linkspan when the bow visor or side hinged doors have been opened. Ramps may also be fitted internally to give access from deck to deck. These can be hydraulically or mechanically tilted to serve more than one deck and can be fixed in the horizontal position to serve as decks themselves. In some ships they can even be raised into the hatch space and serve as weathertight covers.
Stern ramps can be fixed axial ramps, fixed quarter ramps, slewing ramps or semi-slewing quarter ramps. The axial stern ramp may also serve as the stern door and can be lowered or raised hydraulically or by wire rope arrangements. The quarter ramp was designed for ro-ro ships using ports which are not provided with right angled quays or link span connections. The large articulated quarter ramp is raised and lowered by wire rope purchase arrangements to hydraulic winches. Slewing ramps serve a similar purpose to the quarter ramp, but are more flexible. The slewing ramp moves around the stern on a curved guide rail, the movement being affected by the lifting and lowering wire purchases which are led to hydraulic winches.
Автоматизация на судне
Automation. Bridge control.
INTRODUCTION
Automation is a subject which receives considerable attention in marine spheres; indeed it is becoming rare to find a ship that does not have some form of automatic means remote control forengines, power plants navigation and other equipment. Automatic control is more accurate and continuously watchful than manual control can ever be. Its installation, besides giving engine-room personnel more time to deal with maintenance problems, results in saving of fuel, maintenance costs, and out-of-service time due to failure. The major benefit of shipboard automation is the saving in operating cost resulting from a reduction of crew. This can readily be achieved through the installation of remotely operated valves in the ship's flow systems, the installation of sensors and the grouping of control and monitoring devices for convenient operation in the central control station.
The remote control room is air-conditioned and insulated. The main items which can be controlled from the room are: main engine, steam plants generators, auxiliary machinery, pressures, levels, temperature regulation and readings, alarms, communications, boiler service.
The latter includes visual instruments, status signal lights, alarms, graphic displays, and automatic data-logging equipment. Data logging improves supervision efficiency and often spots incipient faults before the human eye.
Automated systems developed and fitted to-date are, in the main, to control temperatures and pressures, to control combustion, steam pressures, etc. in steam plant and to control fuel systems, cooling and lubrication systems in Diesel plant. As more efficiency is called for, and pressures rise in Diesel machinery as do steam conditions for turbines, automatic supervision becomes increasingly necessary. A monitoring network increases the reliability in the operation of the ship, economizes overhaul and contributes to the ship's classification for unmanned engine room.
WORDS AND EXPRESSIONS:
to deal with maintenance problems — заниматься обслуживанием
to result in savings of fuel — в результате приводить к экономии топлива
due to failure— из-за поломки
remotely operated valves — клапаны дистанционного управления
sensors and monitoring devices — чувствительные элементы и контрольные приборы
status signal lights — сигнальные лампы
data-logging equipment — автоматические записывающие приборы (самописцы)
to improve supervision efficiency — улучшать эффективность контроля
to spot the faults— распознавать неисправности, ошибки
steam conditions — параметры пара
monitoring network — цепи контроля
unmanned engine room or unattended machinery space (UMS) — машинное отделение с безвахтенным обслуживанием
Exercise 1.Answer the following questions:
1. For what equipment can the remote control be used? 2. What does the automatic control result in? 3. Name the major benefit of shipboard automation, will you? 4. Where are the remotedly operated valve installed? 5. Enumerate the main items which can be controlled from central control room, can you? 6. What equipment does the control station include? 7. Say what parameters are automatically controlled in steam plants. 8. Say the same about Diesel plant. 9. What does a monitoring network increase? 10. Does the automatic control economize overhaul? If so, prove your opinion.
Exercise 2. Write an annotation to the text.
BRIDGE CONTROL SYSTEM FOR MAIN DIESEL ENGINE
The Bridge Control System is a complete control system for main Diesel engines. Direct control from the bridge telegraph without manual intervention from the control room or engine room is possible.
On ships with periodically unmanned engine rooms the bridge control of the main engine is one of the most important functions. Standardized units, operational reliability, easy installation and a small number ofspare parts are characteristic of this system.
Principles of operation. The bridge telegraph acts as a reference transmitter for the propeller speed and is continuously graduated in r.p.m. Alterations of the speed of the main engines are carried out according to fixed programs. They are set up to meet the requirements of each engine and of the ship with respect to overloading and manoeuvrability.
In some cases it is desirable to include safety functions, e.g low lubricating pressure, to obtain automatic speed reduction or to stop machinery. Such functions may be obtained by connecting the necessary number of pressure or thermo-switches. The functions which are required for starting and reversing the main engine are provided by logiccircuitsin the group unit. Such functions are: e.g. injection of toe starting air, positioning of the camshaft and fuel injection during starting. The output from the logic circuits is converted to a suitable power level for control of mechanical actuators on the main engine.
The Bridge Control System has the following basic equipment:
On the bridge - bridge telegraph, control panel, alarm buzzer. On the control desk — order repeater, control panel, alarm bell.
In the engine room — group unit with power supply and circuits for control and indication.
On the main engine - servomechanism, position switches, tachogenerator, electric, pneumatic or hydraulic actuators. The bridge telegraph is used for manual and automatic control. Two synchros are connected to the scale drum as angle transducers. One of them gives a signal for speed, the other is connected to the repeater pointer. The bridge telegraph also has contact functions for logic circuits for the desired direction of rotation. The order repeater indicates the set speed on the telegraph. It has a long pointer which shows the order given and a short reply pointer. The group unit contains units for power supply, indication and control. The control system is housed in aluminium boxes, which give maximum protection from oil, dust and water.
The servomechanism has the following main components:
· a driving unit, which consists of a three-phase motor and an electromagnetic gear-box;
· a position transducer, which is a part of the position servo;
· a position sensing device for control of the acceleration of the main engine.
The tachogenerator measures the speed of the main engine for control of the starting sequence.
WORDS AND EXPRESSIONS:
without manual intervention — без ручного вмешательства
to act as a reference transmitter — действовать как контрольный преобразователь
alterations of the speed— изменения скорости
to set up to meet the requirements — устанавливать, чтобы удовлетворять требованиям
with respect to — по отношению к
alarm buzzer — ревун
angle transducer — угловой преобразователь
short reply pointer — короткий ответный указатель
driving unit — приводящий механизм
electro-magnetic gear-box — электромагнитный редуктор
position transducer — позиционный преобразователь
position sensing device — позиционный чувствительный элемент, устрой
starting sequence — последовательность пусков
Exercise 3.Give the Russian equivalents:
bridge control system, main Diesel engines, bridge telegraph, manual intervention, unmanned engine-room, standardized units, operational reliability, easy installation, spare parts, reference transmitter, propeller speed, to meet the requirements, in some cases, speed reduction, logic circuits, group unit, injection of the starting air, positioning of the camshaft, fuel injection, power level, mechanical actuators, control panel alarm buzzer, order repeater, alarm bell, power supply, scale drum, angle transducer, direction of rotation, set speed, reply pointer, driving unit three-phase motor, electro-magnetic gear-box, position transducer, position servo, position sensing device, starting sequence.
Exercise 4. Translate into English.
1. Управление главными двигателями осуществляется с мостика. 2. Эта система используется на судах с машинным отделением без обслуживающего персонала. 3. Стандартные узлы и надежность в работе характерны для этой системы. 4. Легкость установки и небольшое число запчастей характерныдля этой системы управления. 5. Пуск и реверс главного двигателя обеспечиваются логическими цепями.
Exercise 5.Give the translation to this abstract.
AUTOCHIEF
Main Engine Bridge Control
AutoChief III is a main engine bridge control system for single engine plant with fixed propeller. It is designed for engines having extensive pneumatic manoeuvring equipment delivered as part of the engine in order to get the maximum benefit from the engine standard system. Norcontrol speed-set unit controls set point to main engine standard governor. AutoChief III is an electronic-pneumatic system, using electrical signal transmission from bridge to engine room and between sensors and the central unit. Starting, reversing and, speed are controlled directly by a manoeuvring handle on bridge which also has built-in emergency telegraph system. The engine is automatically protected against rough manoeuvring.
The engine-room panel, which is normally located near by existing f manual manoeuvring system, contains necessary test and simulating facilities. The electronic logic isconcentrated on a minimum number of cards, which results in low spare part costs.
Вспомогательные механизмы.
Auxiliaries. PUMPS
Exercise 1. Read and learn the following words and expressions:
| to flow out | вытекать | |
| suction head | высота всасывания | |
| rotation | вращение | |
| rotary | ротационный | |
| arrow | стрелка | |
| acquirement | требование | |
| ammeter | амперметр | |
| to exceed | превышать | |
| single stage | односекционный | |
| rating | расчетная величина | |
| tightness | герметичность, зд: затяжка | |
| packing gland | сальник, уплотнение вала | |
| to trap | захватывать | |
| impeller | крылатка | |
| volute | улитка | |
| output | производительность | |
| plunger | плунжер | |
| discharge head | высота нагнетания | |
| reciprocating | поршневой | |
| screw | винтовой | |
| centrifugal | центробежный | |
| gear | шестерёнчатый | |
| vane | лопастной | |
| axial-plunger | аксиально плунжерный | |
| jet | струйный |
Exercise 2. Read and translate the text
Marine Pumps
On board ship, pumps are used for a number of services. Pumps feed water to the boilers, draw condensate from the condensers, supply sea water to the fire-main, circulate cooling water for the main and auxiliary engines cooling system, coolers and condensers, empty the bilges, transfer fuel oil, pump in and out ballast water, discharge fuel oil to the burners and fuel injection valves, circulate lube oil to bearings and gears of the propulsion plant components.
Every pump has a power end, which may be a steam turbine, a reciprocating engine or an electric motor, and a liquid end where the liquid enters and leaves the pump.
The suction head means the pressure of the liquid entering the pump, or the difference in the level of liquid with respect to the level of the pump on the suction side. The discharge head means the pressure of the liquid leaving the pump, or the level of liquid with respect to the level of the pump on the discharge side.
Most marine pumps are of reciprocating, rotary, centrifugal, or jet type.
The reciprocating pump moves liquid or gas by means of a piston or plunger which goes back and forth or up and down within a cylinder containing a suction valve and a discharge valve. An adjustable relief valve is fitted to the discharge chamber to protect the pump and piping against excessive pressure.
All rotary pumps work by means of rotating parts, which trap the liquid at the suction side and force it through the discharge outlet. Classification of rotary pumps is generally made according to the type of rotating elements: screw, gear, vane, axial-plunger rotary pumps. Rotary pumps are particularly used for pumping oil and other heavy, viscous liquids.
The centrifugal pump utilizes the throwing force of a rapidly revolving impeller. The liquid is drawn in at the center of the impeller and is discharged at the outer rim of the impeller. Centrifugal pumps are widely used on board ship for pumping, no viscous liquids. Fire pumps usually are single stage, double suction, volute type either turbine-driven or motor-driven centrifugal pumps. Main feed pump is a high-speed, multistage, turbine driven, horizontal or vertical pump.
Jet pumps, unlike other types of pumps, use the Venturi effect to move fluid from one location to another, it means that the fluid is drawn into the pump passing through a constricted section. While passing through the constricted section the fluid’s pressure decreases, while the fluids velocity increases resulting in an increase in kinetic energy that allows fluid to flow.
There are many brands and models of jet pumps available, with some models offering pump capacity of up to a thousand gallons per hour. When choosing these pumps, the first thing should be paid attention to is how much water flow is required.
Exercise 3. Answer the following questions:
1. What is the most often used type of pumps in ships? 2. Where are the pumps to be found? 3. What is the function of the pumps? 4. What does the pump consist of? 5. Is it good when the liquid seeps through the packing? 6. Is impeller keyed onto the shaft? 7. How is the shaft protected against liquid? 8. What should be head of the pump be? 9. If the pump does not deliver water, will you check the casing? Should it be full of liquid? 10. What is recommended to do during long standing still periods?
Exercise 4. Give Russian/English equivalents.
· Steam turbine powered vessel; to handle fresh water; vertical shaft unit; pump casing, coupling; suction nozzle and discharge nozzle; secured by means of studs; grease lubricator; operating features; power requirements; discharge chamber; packing;
· высота всасывания, односекционный, лопастный насос, захватывать, набивка, труба, уплотнительное кольцо, заглушка, мощность, приемное сопло, фланец, предотвращать, корпус, муфта, крылатка, вертикальный агрегат.
Exercise 5.Look through the following information and then make the translation of the part B.
Part A.
During operation
The pump output is to be controlled by operating on the discharge valve and never on the suction valve which must always remain wide open.
Stopping
After switching off the motor close the suction and the discharge valves of the pump.
Part B.Translate the following sentences into Russian.
1. Check the wear of internal pans by throttling the suction valve at the pump and noting the amount of vacuum pulled by the pump. 2. If neither steam nor power is available, move the pump by hand. 3. It may be necessary to renew the gears, the casing or the gaskets which are sometimes fitted between the casing flanges. 4. Have you checked all clearances? If you’ve done it, renew worn parts if necessary. 5. It looks like complete failure of the starboard circulating pump, the jacket water temperature is very high.
DIESEL ENGINE MAINTENANCE
Exercise 1.Answer the following questions.
1. What is the diesel engine? 2. What cycles does the diesel engine have? 3. What is stroke? 4. What does the four-stroke cycle consist? 5. How is the four-stroke cycle completed? 6. What is going on at the top dead centre? 7. What is going on at the bottom dead centre? 8. How is the two-stroke cycle completed? 9. What is used instead of valves? 10. How does the two-stroke cycle work?
| maintenance | содержание и техническое обслуживание, техническая эксплуатация, уход, (текущий) ремонт | |
| dipstick | футшток | |
| to stand still | находиться не в рабочей состоянии | |
| draining | слив | |
| to unscrew | отвинчивать | |
| to screw | завинчивать | |
| drain plug | сливная пробка | |
| bottom | дно, днище | |
| crankcase | картер двигателя | |
| to fill; to refill | наполнять; наполнять вновь | |
| refilling | повторное наполнение | |
| to wipe | протирать | |
| rag | ветошь | |
| fluff | пух, пушок, ворс | |
| cotton waste | зд. хлопчатобумажная ветошь | |
| to dip | погружать, окунать | |
| lube oil suction strainer | фильтр масла на входе | |
| sump | отстойник, сборник, сточная цистерна | |
| crack | трещина | |
| upper | верхний | |
| piston ring | поршневое кольцо | |
| condition | состояние | |
| deposits | отложения | |
| carbon | нагар | |
| excessive | излишний | |
| externally | с наружной стороны | |
| scale | накипь | |
| wear | износ | |
| to renew | заменять | |
| top | верхняя часть | |
| to adjust | регулировать | |
| clearance | зазор | |
| joint | соединение | |
| lever | рычаг | |
| alignment | регулировка, выравнивающая, центровка, настройка, просветка (линий вала) | |
| bearing | подшипник | |
| readings | показания, данные, замеры |
Exercise 2. Read and translate the text
Check the lube oil pressure daily. The pressure should be 1,5 Kg per sq.cm = 21 Ibs/sq. in (psi). Keep the oil level up to the full mark of the dipstick. Make control when the engine stands still. The lube oil should be changed the first time after 50 working hours, the next time after another 150 working hours and then at least once a year. Draining is made by unscrewing the drain plug at the bottom of the crankcase just after stopping the engine when the oil is warm and easy to drain. Before refilling with fresh oil wipe out the inside of the crankcase with a clean rag (use material free from fluff, do not use cotton waste). Dip the rag in gas oil and clean the lube oil suction strainer placed on the drain plug and clean the sump. When changing the lube oil, clean the lubricating oil filter with petrol or gas oil. Refill the sump with fresh lube oil.
Pistons should be examined frequently for cracks. The upper piston rings should be examined once a month during the first six months service and than as necessary depending on their condition. At intervals of six months piston heads if cooled mast be examined for deposits of carbon in cooling spaces -and cooling pipes. Exhaust valves, manifold and cylinder ports should also be examined and excessive carbon deposits should be removed. Cylinder liners must be examined externally for deposits of scale. The liners should also be examined for wear and renewed if necessary. The clearance of the connecting rod - top and bottom ends should also be examined and adjusted if necessary. At intervals of one year the manoeuvring gear should be examined for wear at the joints of levers and rods. The alignment of the crankshaft should be checked and corrected if necessary. The main bearings, should be examined and readings taken for wear.
Exercise 3. Answer the questions.
1) How often should the lube oil pressure be checked?
2) What should be the pressure? When should the lube oil be changed the first time?
4) How is draining made? When is the oil easiest to drain?
5) Where is the drain plug positioned?
7) When is it necessary to wipe out the inside of the crankcase?
8) What should the pistons be examined for?
9) Where is usually carbon deposited? What should be done with carbon deposits?
10) How often should the maneuvering gear be examined?
Exercise 4. Give the Russian equivalents of the following.
lube oil pressure, drain plug, inside of the crankcase, lube oil suction strainer, deposits of scale
Exercise 5.Translate into Russian
Explosion in crankcase. The usual cause is presence of mixture of oil and air at concentration higher then nominal. In addition there must be a source of high temperature, sufficient to start combustion. It is called a hot spot. The explosion causes a flame and pressure wave. To prevent explosion you should minimize oil and air mixture and be careful during ventilation of crankcase. On some ME special crankcase relief valves are installed.
Exercise 6.Made up a dialogue of your own based on the one given below.
ENGINE DAMAGE
A.: Which of the several causes of ignition failures is most likely to occur?
В.: Failure of the fuel supply is the most common cause, for the reason that the fuel pump is very sensitive to the presence of air and unless great care has been exercised in clearing air out of the fuel lines, the pump will not deliver oil to the injection valves. This is especially true after the fuel lines or pump have been opened up for any reason.
A.: How is air cleared out of the fuel lines?
В.: Most installations include a by-pass valve in each fuel oil discharge line, adjacent to the injection valve. By opening these valves and operating the hand pumps on the fuel measuring pump, oil is forced through the pump and pipe line and out through the by-passes, carrying the air with it. When only oil flows from the by-passes the valves are closed and a few strokes given to the hand pumps to force some oil into the injection valves.
A.: How is the compression pressure measured?
В.: With the indicator, cutting out one cylinder at a time and indicating that cylinder while the rest of the cylinders operate on fuel or starting air. Both methods should be used in order to determine the difference in compression with hot cylinders and with cold.
A.: How is the compression pressure adjusted?
В.: By decreasing or increasing the linear clearance between piston and cylinder head. This is usually done by increasing or reducing the thickness of shims under the foot of the connecting rod.
A.: What are the principal sources of knocks in the Diesel engine?
В.: The large bearings, the valve gear, or the interior of the cylinders. Bearing knocks are caused by too much clearance. Valve gear knocks may be caused by excessive roller clearance, worn or broken rollers, or sticking valve stems. Knocks inside the cylinder are caused by too early injection, excessive lift of air injection valve at low speed, injection air pressure too high, or stuck piston rings.
A.: How is the separation of the two halves of the box usually obtained?
В.: By placing sheet metal shims between the abutting surfaces.
A.: How is bearing clearance usually measured?
В.: By placing strips of soft lead wire in the bearing and setting up the bolts. The thickness to which the lead wire is mashed will be equal to the clearance.
A.: How is a bearing refitted?
В.: By scraping the bearing surface of the boxes with steel scrapers until all the high spots are removed and even contact is obtained between bearing and boxes.
***
A.: What is the best method of keeping a check on crank shaft alignment and main bearing wear?
В.: By the use of a bridge gauge, on which are stamped the heights of the crank shaft at the main bearings at the time the engine was installed. Periodical measurements with this gauge, compared with the original measurements, will indicate any dropping of the shaft.
A.: How are the cylinders lubricated?
В.: By means of small oil pumps, assembled into multiple units called mechanical oilers, which are operated by linkages from any convenient moving part of the engine. These pumps feed the oil in drops, at a rate that can be regulated by small adjusting screws, into small pipes leading to the cylinders.
A.: For what other purpose is the compressor used besides supplying injection air?
В.: The compressor always has a capacity in excess of the amount required for spraying the fuel. The excess air is bypassed into the starting air tanks to supply air for starting the engine.
A.: Why is the injection air usually compressed in three stages instead of one?
В.: Because the temperature at the end of a single compression would be excessive. By performing the compression in three stages the air can be cooled after each stage in the compression. In this way the heat is easily handled and the amount of power required to compress a given quantity of air is greatly reduced.
Бункеровка
BUNKERING OF SHIPS
Notes to the text:
a compliance – соответствие a sample [s'a:mpl] – образец
a spark – искра sawdust – опилки
spillage – разлив a driptray – поддон
a scupper – шпигат to plug – затыкать
a hose – шланг capacity – вместимость
an amount – количество a manifold – трубопровод
to fine – штрафовать a vent – вентиляционное отверстие
a procedure [pr ∂'si:dz ∂ ] – процедура a grade – марка топлива sulphur content – содержание серы flash point – температура вспышки
Exercise 1. Read the text and be ready to answer the following questions:
1) How many logical parts can this text be divided into?
2) What names can be given to each logical part of text?
The bunkering starts a few days before when the Chief Engineer contacts the operators and discusses the conditions of bunkering operations with them. Before that the shipmanager arranges the delivery of fuel oil, its quantity, grade, and cost.
After the vessel is securely moored to the bunkering tanker (if fuel oil is supplied from the bunkering tanker) the fuel oil certificate is checked. The Bunker Delivery Note is necessary to check the compliance of the delivered oil. It is kept on board for three years after the fuel delivery. The fuel sample is attached. A supplier is responsible to provide this sample but it can be taken onboard as well. The sample is kept onboard for one year.
The Bunker Delivery Note has:
· name and IMO (International Maritime Organization) · product name;
number of the ship; · quantity (metric tones);
· port; · density;
· date of delivery; · sulphur content;
· name, address, and telephone number of fuel oil · flash point.
supplier;
Bunkering is a dangerous operation that must be carried out very carefully. Before it begins the watchkeeping officer informs the crew about the start of the bunkering operation and gives an order not to smoke on the deck. He also checks that red light/flag Bravo is displayed and there are not hot works that cay produce a spark.
Each vessel has a schedule of bunkering operations where crewmembers can learn when they participate in bunkering and what their duties are. They will also have a meeting with the 3rd or the 2nd Engineer to discuss actions during bunkering in more detail.
At the same time the crew prepares the bunkering station. They supply it with sawdust, rags, buckets with sand, fire extinguishers, and other oil spill absorbent materials in case of accident spillage, pollution, or fire. Driptrays are placed under the flanges. All drain pipes and scuppers on the deck must be plugged. Flanges of the fuel hoses or pipes are connected and firmly tightened with the help of nuts and bolts.
The service staff is supplied with a portable radio to communicate with the engine-room, bridge, bunkering barge, or coast bunkering personnel. And there must always be a visual watch during the whole operation.
The Third Engineer takes readings in all fuel tanks and writes them down in the log-book. He opens the valves on the tanks that will be filled with fuel. When fuel oil system is prepared the Third Engineer reports to the Chief Engineer that everything is ready for bunkering.
The Chief Engineer orders to start bunkering but first he tests the pressure of flowing liquid. A motorman examines the connection of the hose with the bunkering station flange. If there are no leakages the Chief Engineer orders to continue bunkering with full pressure.
When a tank is filled to 70 % capacity the engineer will give an order to reduce pumping rate to half capacity. When a tank is filled to 80 % capacity the engineer will order the barge to stop pumping for five minutes to avoid air pockets. Then they will continue at a minimum rate until sounding shows 90 %.
After all tanks are full they are checked and readings are taken again. If everything is all right the Chief Engineer signs all documents. Motormen unscrew the connecting nuts of the flanges and remove all fire-fighting equipment. The time when the bunkering was finished and the amount of taken fuel are recorded in the log-book.
Before disconnecting the engineer will ask the barge to blow the hose with air to empty the system. Depending on the contract, the hose will be disconnected by the supplier or by the ship’s personnel. In any case the Chief Engineer must make sure that the hose is empty. A driptray must be placed under the manifold for draining during disconnection. Flanges must be immediately secured on the bunkering hose and the ship’s manifold and fully bolted.
It is necessary to be very careful during the bunkering. In case some fuel oil leaks into the sea, the Port State Control fines the vessel’s officers who were responsible for the leakage. Plus the staff will be punished or fined by the shipowner as well because the fuel oil is very expensive and even the loss of the smallest part of fuel is a big fault of the staff.
Bunkering can cause many problems so the Chief Engineer must be in charge of bunkering. He must prepare written instructions:
· pipeline diagram including location of all valves, pumps, controls, vents, and overflow system;
· number of persons required to be on duty;
· procedures for emergency shut down;
· valve closing procedures;
· pollution reporting procedures;
· scupper plugging reminder;
· ship/shore communication procedures;
· a reminder to check the condition of all bunker hoses and pressure test lines as required.
Exercise 2. Give the Russian equivalents of the following word combinations:
the bunkering tanker; air pockets; the fuel oil certificate; valve closing procedures; the Bunker Delivery Note; pollution reporting procedures; the fuel sample; scupper plugging reminder; a fuel oil supplier; ship/shore communication procedures; the bunkering station flange; bunker hoses; pumping rate; pressure test lines.
Exercise 3. Answer the following questions:
1. What are the actions of the Chief Engineer and the shipmanager before the bunkering starts? 2. When is the fuel oil certificate checked? 3. How many years is the Bunker Delivery Note kept on board after the fuel delivery? 4. What information does the Bunker Delivery Note have? 5. What does the watchkeeping officer do before the start of the bunkering operation? 6. What does the crew prepare the bunkering station with? 7. What is the service staff supplied with? 8. What duties does the Third Engineer have during bunkering? 9. Who reports to the Chief Engineer that everything is ready for bunkering? 10. Who orders to start bunkering and to continue it? 11. What does a motorman examine? 12.What order will the engineer give when a tank is filled to 70 % capacity? 13. Why will the staff be punished or fined by the shipowner because of the fuel oil leakage? 14. What written instructions must the Chief Engineer prepare?
Exercise 4. Find correspondences:
1) the service staff a) must be in charge of bunkering and
prepare written instruction;
2) the engineer b) unscrew the connecting nuts of the
flanges and remove all fire-fighting equipment;
3) the Port State Control c) informs the crew about the start of the
bunkering operation and checks that red
light/flag Bravo is displayed;
4) the crew d) opens the valves on the tanks that will be filled
with fuel;
5) the watchkeeping officer e) fines the vessel’s officers who were
responsible for the leakage;
6) the Chief Engineer f) is supplied with a portable radio to communicate
with the engine-room, bridge, bunkering barge,
or coast bunkering personnel;
7) the Third Engineer g) prepares the bunkering station;
8) motormen h) will order the barge to stop pumping for five
minutes to avoid air pockets when a tank is
filled to 80 % capacity.
Exercise 5. Find the correspondent English equivalents in the text:
обсуждать условия бункеровочной операции; поставка жидкого топлива; быть ответственным за обеспечение этого образца топлива; принимать участие в бункеровке; обеспечивать опилками, ветошью, ведрами и огнетушителями; подписать все документы; проверить соединение шланга; открутить соединяющие гайки фланца; быть оштрафованным судовладельцем.
DOCUMENTS
Note of protest for bunkering operation
Read the text and tell what to do (one by one) starting with the following phrasesIn case of tanks overflow it is necessary…; In case of tanks overflow it is important…; In case of tanks overflow you should take such a measure as …; In case of tanks overflow immediately….
In case of tanks overflow, immediately take such measures as:
· Stop all transfer of cargo and bunkering operations, and close manifold valves.
· Sound the General Alarm, and start emergency procedures.
· Inform the bunkering personnel about the incident.
· Begin clean up procedures.
· Prepare portable pumps if it is possible to transfer the overflowed