u.s.c.g. merchant marine exam qmed q800 junior engineer ... · a two-stroke cycle diesel engine...

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U.S.C.G. Merchant Marine Exam

QMED

Q800 Junior Engineer, Part I

(Sample Examination)

of 25 Q800 Junior Engineer, Part I

8/28/2019

Q800 Junior Engineer, Part I U.S.C.G. Merchant Marine Exam QMED Illustrations: 9

Choose the best answer to the following Multiple Choice Questions.

1. Which of the listed types of superchargers will NOT have a volumetric capacity proportional to engine speed?

• (A) Exhaust gas turbocharger o (B) Roots blower o (C) Piston type blower o (D) Vane type blower

If choice A is selected set score to 1.

2. What statement is true concerning the charge air system of a modern turbocharged slow-speed two-stroke cycle diesel engine?

• (A) An electrically driven auxiliary blower is usually provided because the turbocharger cannot provide enough air at low engine speeds and loads.

o (B) A mechanically driven auxiliary blower is usually provided because the turbocharger cannot provide enough air at high engine speeds and loads.

o (C) An electrically driven auxiliary blower is usually provided because the turbocharger cannot provide enough air at high engine speeds and loads.

o (D) A mechanically driven auxiliary blower is usually provided because the turbocharger cannot provide enough air at low engine speeds and loads.


3. During the valve overlap period, the exhaust pressure of a turbocharged, four-stroke cycle diesel engine must be less than the intake manifold pressure to ensure __________.

• (A) effective cylinder scavenging and cooling o (B) constant pressure from the turbochargers o (C) cooler operation of the exhaust system o (D) effective constant pressure for turbocharger operation


4. The load is always placed on the lower half of the main bearings in a __________.

• (A) two-stroke cycle engine o (B) four-stroke cycle engine o (C) reverse cycle engine o (D) double acting engine



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5. If the compression ratio is increased on any diesel engine, __________.

o (A) the expansion ratio will decrease o (B) combustion will be slowed down o (C) thermal efficiency will decrease • (D) thermal efficiency will increase

If choice D is selected set score to 1.

6. Which of the bearings listed below is most widely used for the main and connecting rod bearings of a modern high-speed diesel engine?

• (A) Precision insert o (B) Steel-lined o (C) Poured babbitt, self-aligning o (D) Split roller


7. In the illustrated diesel engine, which label points to the piston? Illustration MO-0122

o (A) 3 • (B) 4 o (C) 6 o (D) 7

If choice B is selected set score to 1.

8. Which of the listed diesel engine operating conditions should be checked immediately after any diesel engine is started?

• (A) Lube oil pressure o (B) Exhaust temperature o (C) Water level in the expansion tank o (D) Lube oil level


9. Babbitt is a metal alloy commonly used for lining __________.

o (A) valve seats o (B) shim stock o (C) salt water piping • (D) precision bearings



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Q800 Junior Engineer, Part I U.S.C.G. Merchant Marine Exam QMED Illustrations: 9 10. In addition to checking the lube oil sump level and temperature of a line shaft steady bearing, what

else must be checked for?

• (A) Ensure free rotation of the oiling ring with the shaft. o (B) Ensure that the oiling ring does not rotate with the shaft. o (C) Ensure flow through the gravity head tank overflow sight glass. o (D) Ensure adequate lube oil pump discharge pressure.


11. What type of clutch is used in the illustrated medium-speed diesel engine reduction gear? Illustration MO-0085

o (A) Electromagnetic • (B) Pneumatic o (C) Mechanical o (D) Hydraulic


12. Which of the devices listed is commonly used to compensate for the expansion and minor misalignments occurring between the main turbine rotor and the reduction gear?

• (A) Gear-type flexible coupling o (B) Expansion gear o (C) Quill shaft o (D) Sliding sleeve


13. Reduction gear casings are vented in order to __________.

o (A) allow windage to exist for cooling the gears • (B) avoid a buildup of pressure within the gear case o (C) minimize lube oil foaming within the case o (D) allow for axial clearance between the gears


14. What is the function of the main thrust bearing?

o (A) Prevents lateral movement of the slow-speed gear. • (B) Transmits propeller thrust to the hull. o (C) Keeps spring bearings in line. o (D) Prevents main reduction gear axial movement.



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Q800 Junior Engineer, Part I U.S.C.G. Merchant Marine Exam QMED Illustrations: 9 15. On a large diesel engine installation, crankshaft axial alignment is maintained by the __________.

o (A) piston rod guides • (B) engine thrust bearing o (C) crosshead bearing o (D) main shaft flexible coupling


16. Movement of the pump control rack in a fuel injection system using individual plunger-type pumps __________.

o (A) varies the compression of the delivery valve spring o (B) changes the position of the fuel inlet ports • (C) varies the quantity of fuel delivered o (D) changes the length of the pump stroke

If choice C is selected set score to 1.

17. Which of the fuel injection systems listed uses a spring loaded differential spray needle valve and an individual pump for each cylinder?

o (A) Common rail injection o (B) Air injection • (C) Jerk pump injection o (D) Distributor injection


18. For a continuous operation diesel engine, a duplex filter unit would be the best arrangement because __________.

• (A) changing filter elements would not interrupt engine operation o (B) filtering occurs twice in each pass of oil through the system o (C) clogging will not occur o (D) dropping pressure is half of that through a single filter unit


19. An increase in the air inlet manifold pressure of a diesel engine will result in a/an __________.

o (A) decrease in maximum cylinder pressure o (B) increase in ignition lag • (C) decrease in fuel consumption per horsepower-hour o (D) decrease in exhaust manifold pressure



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Q800 Junior Engineer, Part I U.S.C.G. Merchant Marine Exam QMED Illustrations: 9 20. What is the function of the aftercoolers installed in the diesel engine air intake system?

o (A) Decrease the air density o (B) Increase the exhaust temperature o (C) Decrease the lube oil temperature • (D) Increase the air density


21. A naturally aspirated diesel engine at full throttle will have an intake manifold pressure __________.

• (A) slightly less than atmospheric pressure o (B) approximately equal to exhaust manifold pressure at all times o (C) that is widely fluctuating o (D) constantly decreasing as engine load increases


22. The lube oil strainer shown in the illustration is used on the reduction gear of a mid-size diesel engine. The strainer elements consist of __________. Illustration MO-0057

o (A) pleated paper • (B) metal disks o (C) fibrous braid o (D) wire mesh


23. The purpose of an oil mist detector in a main propulsion diesel engine is to warn of __________.

o (A) excessive carbon buildup in the lube oil • (B) a possible overheated bearing o (C) low cylinder oil pressure o (D) excessively high crankcase vacuum


24. Which of the following methods is normally used to lubricate bearings in a small high-speed diesel engine?

o (A) Mechanical lubricators o (B) Splash lubrication • (C) Pressure lubrication o (D) Sight feed lubricators



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Q800 Junior Engineer, Part I U.S.C.G. Merchant Marine Exam QMED Illustrations: 9 25. A two-stroke cycle diesel engine requires less starting air than a four-stroke cycle diesel engine, of

equal displacement, because the two-stroke cycle diesel engine __________.

o (A) has little or no internal friction o (B) has a lower effective compression ratio o (C) operates with scavenge air under a positive pressure • (D) operates without energy absorbing intake and exhaust strokes


26. Starting air check valves are held firmly on their seats by __________.

o (A) cam rollers on the camshaft • (B) spring force o (C) air pressure on top of the valve differential piston o (D) air pressure on the bottom of the valve differential piston


27. Auxiliary diesel engine electric starting motors use __________.

o (A) 400 cycle per second motor-generator power • (B) battery power direct current o (C) low amperage, high voltage AC power o (D) alternating current transformers


28. When an engine fitted with a hydraulic starting system starts up, the starter is protected from the higher speed of the engine by __________.

o (A) the immediate increase in hydraulic pressure • (B) the overrunning clutch o (C) closing the starting check valves o (D) the pivoting of the shaft from being engaged with the flywheel


29. When an air started, four-stroke cycle diesel engine is being cranked over, the starting air is admitted to each cylinder during the beginning of its __________.

o (A) intake stroke o (B) compression stroke • (C) power stroke o (D) exhaust stroke



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Q800 Junior Engineer, Part I U.S.C.G. Merchant Marine Exam QMED Illustrations: 9 30. The power consumed during the scavenging process of a diesel engine is known as the

__________.

o (A) compression loss o (B) valve loss o (C) back pressure loss • (D) pumping loss


31. The process of scavenging a two-stroke cycle diesel engine serves to __________.

o (A) improve fuel flow volume • (B) cool the exhaust valves o (C) reduce the intake air charge density o (D) increase the temperature of exhaust gases


32. Auxiliary boilers are divided into several classifications, one of which is __________.

o (A) water-tube supercritical circulation • (B) water-tube forced circulation o (C) fire-tube controlled circulation o (D) fire-tube express circulation


33. An exhaust gas bypass is installed on a waste heat boiler in order to __________.

o (A) bypass exhaust gas at high loads to prevent excessive back pressure o (B) bypass a portion of the exhaust gas at peak loads for better efficiency o (C) recycle exhaust gas to the turbocharger • (D) minimize moisture condensation in the boiler gas passages at low loads


34. Which of the following statements concerning fire-tube boilers is correct?

• (A) Combustion gases flow through the tubes. o (B) Flames impinge on the tubes. o (C) Combustion occurs in the tubes. o (D) Water flows through the tubes.



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35. Which of the following statements is correct concerning heat transfer?

o (A) Heat is given off from a high temperature region known as a heat sink. o (B) Heat transfer rate is affected most by the size of the heat sink involved. • (C) Heat transfer rate is affected most by the temperature difference between the heat source

and the heat sink. o (D) Heat transfer by radiation will occur only by mass motion of a fluid substance.


36. Most auxiliary turbine feed pumps do not require an external source of gland sealing steam because they __________.

• (A) exhaust to pressures above atmospheric pressure o (B) operate with only a small amount of axial thrust o (C) operate at relatively low pressures o (D) utilize carbon packing rings at the low-pressure end


37. (The steam drum in a D-type marine boiler __________.

o (A) supports the superheater tube bank o (B) acts as a receptacle for heavy suspended solids in boiler feedwater o (C) maintains circulation by forcing steam bubbles downward in the generating tubes • (D) provides a space for moisture to separate from the steam


38. While raising steam on a cold boiler, the air cock is to be closed after __________.

o (A) the economizer drain is closed o (B) all burners have been lit and firing normally • (C) steam has formed and all air is vented o (D) the boiler is cut in on the line


39. Which of the following statements about boilers is correct?

o (A) No boiler will continue to generate steam after the fires are secured. • (B) A hot boiler will continue to generate steam after the fires are secured. o (C) The water level in a properly operated boiler will not shrink or swell. o (D) Loss of water will not harm a boiler if the water level can be restored.



8/28/2019

Q800 Junior Engineer, Part I U.S.C.G. Merchant Marine Exam QMED Illustrations: 9 40. The cooling water flow from an air ejector intercondenser and aftercondenser is discharged directly

into the __________.

• (A) condensate and feed system o (B) atmospheric drain tank o (C) main condenser hotwell o (D) auxiliary condenser hotwell


41. Under normal conditions, the rate of heat transfer in a feedwater heater is most greatly affected by the __________.

• (A) temperature differential between the steam and feedwater o (B) density of the feedwater o (C) speed of the main feed pump o (D) pH of the feedwater


42. Condensate pumps have distinctly noticeable characteristics and can usually be recognized by their __________.

o (A) speed-limiting governors and closed impellers • (B) large suction chambers and impeller eyes o (C) open impellers and power ends o (D) multiple impellers and pump shaft positions


43. A main condenser utilizing a scoop for the circulation of sea water must be constructed as a __________.

o (A) counterflow heat exchanger • (B) single-pass heat exchanger o (C) two-pass heat exchanger o (D) parallel flow heat exchanger


44. The atmospheric drain tank (ADT) normally drains to the _______.

o (A) distillate tank o (B) main and/or auxiliary air ejector condenser o (C) reserve feed tanks • (D) main and/or auxiliary condenser



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Q800 Junior Engineer, Part I U.S.C.G. Merchant Marine Exam QMED Illustrations: 9 45. Cooling water to the vent condenser in a DC heater is supplied by the _______.

o (A) main feed pump • (B) main and/or auxiliary condensate pump o (C) feed booster pump o (D) salt water circulator


46. The pressure in the feedwater system must exceed boiler steam drum pressure in order to __________.

o (A) prevent air leakage into the feedwater system o (B) remove the steam from the steam drum • (C) force the feedwater into the boiler o (D) prevent water hammer in the lines


47. Under EMERGENCY operating conditions, the proper valve positions for controlling feedwater to the boiler should be the __________.

o (A) auxiliary stop-check valve fully open and the auxiliary stop valve regulated by the feedwater regulator

o (B) auxiliary stop and stop-check valves fully open and the feed pump speed used to regulate the amount of flow

o (C) auxiliary stop-check valve fully open and the auxiliary stop valve used to regulate the amount of flow

• (D) auxiliary stop valve fully open and the auxiliary stop-check valve used to regulate the amount of flow


48. In addition to sensing steam drum water level, what additional sensing input does a two-element feedwater regulator control system utilize?

• (A) Boiler steam flow o (B) Boiler feed flow o (C) Boiler fuel flow o (D) Boiler air flow



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49. According to the illustration, bellows "I" in the gland seal regulator is actuated by ________. Illustration SE-0019

o (A) control air pressure • (B) gland seal steam pressure o (C) steam throttle pressure o (D) lube oil pressure


50. In a gravity lube oil system, a sight glass is installed in a line near the operating platform. This line connects the __________.

o (A) bottom of the gravity tank and the lube oil headers • (B) gravity tank overflow and the sump o (C) bottom of the gravity tank and the sump o (D) gravity tank overflow and the lube oil headers


51. During high-speed operation of the main turbine propulsion unit, the heat absorbed by the lubricating oil is removed by the __________.

o (A) sump vents o (B) lube oil purifier o (C) distillate cooler • (D) lube oil cooler


52. Water is best removed from lubricating oil by __________.

o (A) paper edge filters o (B) silica gel cartridges o (C) pressure filters • (D) centrifuging


53. In a cross-compounded turbine propulsion plant, steam enters the __________.

o (A) high and low-pressure units simultaneously o (B) high-pressure unit and then cross-flows to the condenser • (C) high-pressure unit and then flows through a crossover to the low-pressure unit o (D) high-pressure, intermediate and low-pressure units simultaneously



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Q800 Junior Engineer, Part I U.S.C.G. Merchant Marine Exam QMED Illustrations: 9 54. What is the purpose of the items labeled "moving blades" located on the illustrated steam turbine?

Illustration SE-0003

o (A) Change the direction of travel of the steam. o (B) Convert the potential energy of the steam exiting the nozzle to mechanical energy of rotation. • (C) Convert the kinetic energy of the steam exiting the nozzle to mechanical energy of rotation. o (D) Convert the kinetic energy of the steam exiting the nozzle to potential energy.


55. The adjustable spherically seated self-aligning bearing housings used in main turbines are provided with oil deflector rings. The function of these rings is to __________.

o (A) prevent the leakage of main steam into the oil o (B) direct the flow of oil through the bearing o (C) ensure efficient lubrication of the bearing • (D) prevent the external leakage of oil out of the bearing housing


56. Which of the devices listed is found on an LP main propulsion steam turbine casing?

o (A) HP turbine bypass valve o (B) Duplex set of relief valves o (C) Sliding beam • (D) Sentinel valve


57. What statement is true concerning a propulsion steam turbine turning (jacking) gear?

o (A) The jacking gear splined clutch is associated with the high-pressure turbine second reduction pinion.

• (B) The jacking gear splined clutch is associated with the high-pressure turbine first reduction pinion.

o (C) The jacking gear splined clutch is associated with the low-pressure turbine second reduction pinion.

o (D) The jacking gear splined clutch is associated with the low-pressure turbine first reduction pinion.



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58. A common method of preheating main turbine lube oil prior to rolling over the main unit would be to ________.

• (A) operate the lube oil purifier on the main lube oil sump o (B) run both the lube oil pumps simultaneously o (C) bypass the lube oil gravity tank o (D) slightly increase gland sealing steam pressure


59. In order to take suction on the lube oil drain tank cofferdam with the bilge pump shown in the illustration, how many suction side valves must be open? Illustration GS-0042

o (A) One • (B) Two o (C) Three o (D) Four


60. The rudder torque capacity of the four ram steering gear illustrated is rated at 44,210,000 inch-pounds with one power unit in operation. If the four ram system was able to be operated as a two ram system with both power units on line, what would be the available torque? Illustration GS-0067

o (A) 11,052,500 inch-pounds • (B) 22,105,000 inch-pounds o (C) 44,210,000 inch-pounds o (D) 88,420,000 inch-pounds


61. Rudder position is shown on the bridge by the __________.

• (A) rudder angle indicator o (B) follow-up gear o (C) telemotor position o (D) Rapson slide indicator


62. In which lubrication application is a lubricating oil with demulsibility properties most likely to be used?

o (A) Gas turbine lubricating oil. • (B) Steam turbine lubricating oil. o (C) Trunk type diesel engine lubricating oil. o (D) Crosshead diesel engine cylinder oil.



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Q800 Junior Engineer, Part I U.S.C.G. Merchant Marine Exam QMED Illustrations: 9 63. The process of boiling sea water in order to separate it into fresh water vapor and brine is usually

defined as __________.

o (A) dissolution o (B) condensation o (C) dehydration • (D) evaporation


64. Vapor is produced in a flash evaporator by introducing __________.

o (A) heated water into a high-pressure area o (B) steam through cooling coils o (C) steam through heating coils • (D) heated water into a low-pressure area


65. Which of the following represents the motivating power fluid used in conjunction with the ejector pumps on plate type evaporators?

o (A) The motive power is the brine pump output, prior to being discharged overboard. o (B) The motive power is the jacket water flowing through the ejectors. • (C) The motive power is the feedwater supply. o (D) The ejectors do not require a motive power.


66. Fuel oil is regularly transferred to the day tank in order to __________.

o (A) allow impurities to settle out of the fuel o (B) allow for decanting of water o (C) make fuel available for immediate use • (D) all of the above


67. What is used to prevent contamination of a potable water system supplying a plumbing fixture such as a galley sink from a backup of sewage sanitary drains?

• (A) Location of the potable water spigots above the rim of the galley sink. o (B) Location of the potable water spigots below the rim of the galley sink. o (C) A "P" trap in the drain line draining sewage waste from the galley sink. o (D) Check valves in the potable water supply lines delivering water to the galley sink.



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68. As demand on the device shown in the illustration fluctuates in the pressure range of 100 to 110 psi,the output of the unit is controlled by __________. Illustration GS-0119

o (A) proportional modulation of the compressor speed• (B) the modulation of the opening of a butterfly valve located in the air intakeo (C) change in control pressure to modulate the discharge of compressed air to the atmosphereo (D) complete shut down until the lower pressure limit is reached causing it to restart


69. One of the functions of the component labeled "E", shown in the illustration, is to __________.Illustration GS-0119

• (A) act as a lube oil sumpo (B) act solely as a heat exchangero (C) act as a cyclonic pneumatic dehydratoro (D) provide storage for compressed cryogenic gases


70. The diaphragm orifice labeled "H", as shown in the illustration is used as a/an __________.Illustration GS-0155

o (A) pressure reducero (B) check valveo (C) injector• (D) time delay



8/28/2019

National Maritime Center Serving Our Nation's Mariners

9/24/2018

GS-0042

Adapted for testing purposes only from SEWARD, Marine Engineering

Copyright © 1968 by The Society of Naval Architects and Marine Engineers

Further reproduction prohibited without permission of 25 Q800 Junior Engineer, Part I

National Maritime Center Serving Our Nation's Mariners

9/24/2018

GS-0067

Adapted for testing purposes only from SOUCHOTTE, Marine Auxiliary Machinery

Copyright © 1975 by Butterworth & Co. (Publishers) Ltd.



9/26/2018

GS-0119

Adapted for testing purposes only Sullair® Compressor Series 16 60 & 75 Standard & 24KT Industrial Rotary Screw Air Compressors, Operators Manual and Parts List

Copyright © by Sullair Corporation



9/27/2018

GS-0155

Adapted for testing purposes only from Utilitiesman Basic, Volume 1

NAVEDTRA 14265


National Maritime Center

Serving Our Nation’s Mariners

10/19/2018

Adapted for testing purposes only from GUNTHER, Lubrication

Copyright © 1971 by Raymond C. Gunther

Further reproduction prohibited without permission

MO-0057




10/19/2018

Adapted for testing purposes only from Falk Marine Reduction Drives,

Installation, Operation and Maintenance Manual

Copyright © Falk


MO-0085




10/22/2018

Adapted for testing purposes only from EMD 645E9 Turbocharged Engine Maintenance Manual

Copyright © 1973 Electro-Motive Division, General Motors


MO-0122



10/2/2018

SE-0019

Adapted for testing purposes only from HUNT, Modern Marine Engineer’s Manual, Volume I

Copyright © 1999 by Cornell Maritime Press, Inc.

Further reproduction prohibited without permission of 25

Q800 Junior Engineer, Part I

u.s.c.g. merchant marine exam qmed q800 junior engineer ... · a two-stroke cycle diesel engine...

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