National Maritime Center

Transcription

1 National Maritime Center Providing Credentials to Mariners U.S.C.G. Merchant Marine Exam (Sample Examination) Page 1 of 25

2 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 2. Some diesel engines are supercharged with a. o (A) slam charger (B) turbocharger o (C) fuel atomizer o (D) fuel injector 3. A three-way thermostatic control valve regulates the diesel engine cooling water temperature by passing a portion of the water. o (A) to the expansion tank o (B) around the engine (C) around the cooler o (D) overboard 4. According to the illustrated diesel engine cooling water systems diagram, what fluid is the high temperature central fresh water thermostat designed to maintain? Illustration MO-0129 o (A) The jacket water cooler inlet temperature. o (B) The main engine jacket water inlet temperature. (C) The main engine jacket water outlet temperature. o (D) The jacket water cooler outlet temperature. Page 2 of 25

3 5. Diesel engines are classified as reciprocating internal combustion engines because they. o (A) burn fuel in a combustion chamber that moves back and forth o (B) use a continuous combustion process to impart rotary motion to the pistons o (C) use energy from fuel burned outside their cylinders (D) burn fuel in a closed chamber which imparts linear motion to pistons 6. Which of the following relationships exist between the temperature developed in a combustion space, and the compression ratio of the engine? (A) Higher compression ratios create higher temperatures. o (B) Higher temperatures create higher compression ratios. o (C) Lower temperatures create higher compression ratios. o (D) Higher compression ratios create lower temperatures. 7. 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 8. As found in a reduction gear drive system, thrust bearings serve to. (A) transmit the force produced by the propeller to the structure of the ship o (B) increase the shaft speed o (C) limit the radial movement of the shaft o (D) hold the main engine in place 9. One advantage of electromagnetic slip couplings is. (A) torsional vibrations are reduced o (B) torque increases with a decrease in excitation current o (C) the coupling rapidly responds to sudden changes of load o (D) excitation and induction power losses appear as a change in torque instead of rotational speed between the primary and secondary elements Page 3 of 25

4 10. Kingsbury thrust bearings are lubricated by. (A) flooding the thrust bearing assembly with oil o (B) submerging oil wiper rings in an oil bath o (C) pressure lubricating through internal passages o (D) spraying oil directly on the thrust collar and shoes 11. Fuel injection systems are designed to primarily meter fuel, atomize fuel, and. o (A) create turbulence in the combustion chamber o (B) aid in completing cylinder scavenging (C) inject fuel at the proper time o (D) minimize fuel penetration into the cylinder 12. Fuel injection pumps using the port and helix metering principle requires the use of a. o (A) crosshatched design (B) lapped plunger and barrel o (C) variable stroke o (D) variable cam lift 13. 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 14. Valve '1', as shown in the illustration, should be operated when. Illustration MO-0077 (A) entering or departing port o (B) starting auxiliary boilers o (C) viscosimeter 'V' measures low viscosity o (D) mixing tank is 'full' Page 4 of 25

5 15. Cooling the intake air supplied to a diesel engine will. o (A) reduce mean effective pressure o (B) decrease average compression ratio o (C) decrease air charge density (D) increase peak power output 16. In a naturally aspirated diesel engine, the volume of air intake is directly associated with engine. o (A) compression ratio (B) displacement o (C) fuel pressure o (D) cylinder clearance volume 17. Lubrication for the main reduction gears used with diesel engines is usually supplied by. o (A) oil from the main engine sump (B) an independent lube oil system o (C) the stern bearing head tank o (D) the stern bearing sump tank 18. Where would a coarse screen wire mesh strainer normally be found on a diesel engine lubrication system? o (A) filter bypass return line (B) pump suction line o (C) pump discharge line o (D) gravity tank inlet line 19. A magnetic strainer is primarily used in diesel engine reduction gear oil systems to remove small particles of. o (A) copper o (B) acidic materials o (C) Babbitt (D) ferrous materials Page 5 of 25

6 20. Which of the routine maintenance procedures listed is required for starting air receivers? (A) Frequent draining of accumulated moisture. o (B) Frequent testing of relief valves. o (C) A close watch on temperature to prevent fluctuations in pressure. o (D) Frequent cleaning to remove oil and foreign matter. 21. Hydraulic starters are installed on many lifeboat diesel engines instead of comparable air start systems, because. o (A) hydraulic starters are the least expensive of all starting systems o (B) the system does not require high-pressure piping o (C) hydraulic systems turn diesel engines at higher rates of speed than air starters (D) the system can be manually recharged 22. 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 23. The exhaust system for a turbocharged diesel engine functions to. o (A) power the aftercoolers (B) power the turbocharger o (C) reduce the cylinder scavenge effect o (D) cool the turbocharger 24. Bottom blow valves are installed on auxiliary water-tube boilers to. o (A) completely drain the boiler in an emergency o (B) prevent sludge from forming in the steam drum o (C) remove floating impurities from the boiler water surface (D) remove settled solids from the water drum Page 6 of 25

7 25. As shown in the illustration, the function of component "1" is to. Illustration MO-0128 o (A) generate superheated steam to operate the turbo-generator (B) evaporate circulating boiler water into saturated steam o (C) maintain a water level in the steam drum o (D) condense excess steam produced in the boiler 26. The tube sheets installed in a fire-tube auxiliary boiler are normally connected by. o (A) girder stays (B) fire-tubes and stay-tubes o (C) external boiler plating o (D) separate crown sheets 27. By which of the listed methods may heat be transferred from one body to another? o (A) Conduction o (B) Radiation o (C) Convection (D) All of the above 28. A back pressure trip on a ship's service turbo-generator functions to trip the turbine under what circumstance? o (A) amount of cooling water to the condenser is excessive (B) amount of cooling water to the condenser is insufficient o (C) gland seal leakoff pressure is too high o (D) lubricating oil pressure is too low 29. The steam drum in a D-type marine boiler. o (A) supports the superheater tube bank o (B) maintains circulation by forcing steam bubbles downward in the generating tubes o (C) acts as a receptacle for heavy suspended solids in boiler feedwater (D) provides a space for moisture to separate from the steam Page 7 of 25

8 30. As shown in the illustrated D type single furnace boiler, what does item "H" represent? Illustration SG-0008 (A) Feedwater economizer o (B) Combustion air heater o (C) Integral superheater o (D) Auxiliary steam desuperheater 31. While vacuum is being raised on the main unit and the turbine warmed, condensate is recirculated to the main condenser to. o (A) provide a condenser vacuum seal o (B) cool the main condenser shell for better vacuum o (C) maintain a proper DC heater water level (D) ensure the condensation of air ejector steam 32. While underway, vacuum in the main condenser is primarily caused by the. o (A) suction drawn by the condensate pump o (B) aftercondenser loop seal (C) condensing of the exhausting steam o (D) main air ejector 33. 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) ph of the feedwater o (C) speed of the main feed pump o (D) density of the feedwater 34. Salt water ballast is to be discharged into the #6 port and starboard wing tanks. Which combination of valves, illustrated, must be opened, and which valves should be closed? Illustration GS-0139 o (A) 1, 2, 5 and 6 open; 4, 7, 8 and 9 closed. o (B) 1, 2, 7 and 9 open; 3, 4, 5, 6, 8 and 10 closed. (C) 1, 3, 5, 6, 8 and 10 open; 2, 4, 7 and 9 closed. o (D) 3, 4, 7 and 9 open; 1, 2, 5, 6 and 10 closed. Page 8 of 25

9 35. One of the consequences in continuing to operate a centrifugal bilge pump with the discharge valve closed, is that the. (A) pump will overheat o (B) motor overload will open o (C) motor will overheat o (D) relief valve will open 36. If it is necessary to prevent the rudder from moving while a repair is made on the steering system using the illustrated actuator. Illustration GS-0116 o (A) tighten the locking screws in item "S" o (B) screw in the locking pin, item "J" (C) secure the valves in the supply and return lines o (D) tighten the locking pins, item "H" at each position of item "I" to keep the rudder from swinging 37. 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 38. In order for microbiological growths to thrive in a fuel tank it is necessary for. o (A) vanadium to be present o (B) low temperatures to exist (C) moisture or water to be present o (D) electrolysis to be occurring 39. The depth of fuel oil in a tank is normally measured through the. o (A) vent line o (B) overflow line o (C) feed line (D) sounding tube Page 9 of 25

10 40. In which lubrication application is a lubricating oil with demulsibility properties most likely to be used? o (A) Crosshead diesel engine cylinder oil. o (B) Gas turbine lubricating oil. o (C) Trunk type diesel engine lubricating oil. (D) Steam turbine lubricating oil. 41. In a forced-feed lubrication system, what statement is true concerning lube oil reservoir/sump residence time? o (A) The lower the oil level, the longer the residence time, and the cooler the oil will be as delivered by the pump. o (B) The lower the oil level, the shorter the residence time, and the cooler the oil will be as delivered by the pump. o (C) The lower the oil level, the longer the residence time, and the hotter the oil will be as delivered by the pump. (D) The lower the oil level, the shorter the residence time, and the hotter the oil will be as delivered by the pump. 42. Which of the following desalination plants will always require a sterilizer when providing water to a potable water system? o (A) Multi-stage flash type unit (B) Reverse osmosis type unit o (C) Titanium plate type unit o (D) Submerged tube type unit 43. The cylinders and intercoolers of most low-pressure air compressor's are cooled by. o (A) oil (B) air o (C) water o (D) CO2 Page 10 of 25

11 44. For any given volume of compressed air produced by a multi-stage air compressor, interstage cooling will. (A) decrease the power required for compression o (B) allow isothermal compression of the air charge o (C) allow the compressed air volume to remain constant o (D) increase the power required for compression 45. If an air compressor is used to supply air primarily to the combustion control system and other pneumatic controllers, the entire system is known as the. o (A) forced draft air system o (B) supply air system (C) control air system o (D) ships service air system 46. Which of the following statements correctly describes the construction of the close coupled sanitary pump shown in the illustration? Illustration GS-0070 o (A) The pump suction and discharge connections are made with screwed pipe fittings. o (B) The pump impeller is classified as double suction. (C) The pump and motor have a common shaft. o (D) The pump housing and motor frame provide for radial adjustment of the shaft coupling. 47. When any low-pressure distilling plant is operated with less than the designed vacuum, the. o (A) scale formation decreases o (B) capacity increases (C) heat level rises o (D) heat level drops 48. 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) dehydration o (C) condensation (D) evaporation Page 11 of 25

12 49. The temperature of the steam flow to the salt water feed heater, in a flash type evaporator can be manipulated by a/an. o (A) pressure regulator within the supply orifice (B) attemporator in the steam supply piping o (C) thermally actuated bypass valve o (D) sensor wired in with the three-way salinity dump valve 50. In a flash type distilling plant, a screen is fitted over the suction connection to the brine overboard pump in order to prevent. (A) scale from passing into the brine pump and clogging impeller passages o (B) the pump from cavitating o (C) electrolysis from occurring in the pump o (D) excessively large salt crystals from damaging the pump 51. Diesel engine jacket water is used in the fresh water distillation process as the. (A) means of heating the feedwater o (B) coolant for the brine cooler o (C) primary means of producing a vacuum within the distiller o (D) coolant for the distillate 52. The automatic recirculating valve in the main condensate recirculating line is controlled by a temperature sensor which is located at the. o (A) main condensate pump discharge o (B) condensate inlet to the main air ejectors (C) air ejector condensate discharge o (D) main condensate pump suction 53. In a main propulsion steam turbine installation, the condensate pump initially discharges to the. (A) air ejector condenser o (B) deaerating feed tank o (C) first stage heater o (D) distillate tank Page 12 of 25

13 54. Which of the following methods is used to securely fasten the Babbitt lining of a reduction gear bearing to its shell? o (A) The Babbitt has a crescent shaped pocket cast symmetrically about the bearing split. (B) The Babbitt is centrifugally spun into the bearings or cast under a pressure head. o (C) The Babbitt is relieved in way of the split and held in place by locking pins. o (D) The Babbitt is securely bonded to the shell by the pressure of the hydrodynamic oil wedge. 55. 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) Quill shaft o (C) Sliding sleeve o (D) Expansion gear 56. Cooling water to the vent condenser in a DC heater is supplied by the. o (A) salt water circulator (B) main and/or auxiliary condensate pump o (C) feed booster pump o (D) main feed pump 57. If a centrifugal main feed pump were operated at shutoff head with the recirculating line closed, which of the following conditions could occur? o (A) An increased water level in the steam drum. o (B) A decreased water level in the DC heater. o (C) Excessive diaphragm seal wear in the feedwater regulator. (D) Flashing at the suction side of the pump. 58. Traditionally, which of the listed refrigerants has been more suitable than the others for use in a centrifugal refrigeration compressor? (A) R-11 o (B) R-12 o (C) Ammonia o (D) Carbon dioxide Page 13 of 25

14 59. What is the color-coding for a storage container of R-134a refrigerant? o (A) grey o (B) green o (C) purple (D) light blue 60. Personnel servicing refrigeration systems and subject to the exposure to commonly used refrigerants should wear what type of personal protective equipment? o (A) an all-purpose gas mask o (B) rubber soled shoes (C) goggles and gloves o (D) a respirator 61. In the presence of an open flame or hot surfaces, chlorinated fluorocarbon refrigerants decompose and form what chemical substance? o (A) petroleum crystals (B) phosgene gas o (C) carbon monoxide o (D) water vapor 62. Which system should be used when required to raise the water level in an idle boiler? o (A) Chemical feed system o (B) Main condensate system o (C) Auxiliary condensate system (D) Main feed system Page 14 of 25

15 63. 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 used to regulate the amount of flow (B) auxiliary stop valve fully open and the auxiliary stop-check valve used to regulate the amount of flow o (C) auxiliary stop-check valve fully open and the auxiliary stop valve regulated by the feedwater regulator o (D) auxiliary stop and stop-check valves fully open and the feed pump speed used to regulate the amount of flow 64. Why are two fuel oil heaters "E" provided in the fuel oil system shown in the illustration? Illustration SG-0009 o (A) Two heaters are necessary when both boilers steam at full load. o (B) Each heater supplies fuel to a different boiler. (C) To provide a backup in case one of the heaters becomes inoperable. o (D) To allow fuel of different temperatures to be provided to each boiler. 65. Fuel oil settling tanks are used to. o (A) precipitate out water and solids o (B) facilitate the stripping of sludge and water o (C) store oil for immediate use (D) all of the above 66. An efficient seal is normally obtained between the upper and lower halves of a turbine casing by. o (A) copper gaskets o (B) asbestos gaskets (C) precision metal-to-metal contact o (D) flexible steel seal strips Page 15 of 25

16 67. On a main propulsion turbine set of a merchant ship, where is the astern staging generally located? o (A) Within the high-pressure turbine (B) Within the low-pressure turbine o (C) Within a separate astern turbine o (D) Within the intermediate pressure turbine 68. What is the purpose of the items labeled "moving blades" located on the illustrated steam turbine? Illustration SE-0003 o (A) Convert the potential energy of the steam exiting the nozzle to mechanical energy of rotation. (B) Convert the kinetic energy of the steam exiting the nozzle to mechanical energy of rotation. o (C) Convert the kinetic energy of the steam exiting the nozzle to potential energy. o (D) Change the direction of travel of the steam. 69. The jacking gear must be engaged as quickly as possible when securing the main turbines in order to. o (A) maintain a constant supply of lube oil to the main unit o (B) permit rapid cooling of the reduction gears o (C) prevent the stern tube bearing from overheating (D) prevent uneven cooling of the turbine rotors 70. Which of the following statements about boilers is correct? o (A) The water level in a properly operated boiler will not shrink or swell. o (B) Loss of water will not harm a boiler if the water level can be restored. (C) A hot boiler will continue to generate steam after the fires are secured. o (D) No boiler will continue to generate steam after the fires are secured. Page 16 of 25

17 National Maritime Center Providing Credentials to Mariners GS /14/2016 Adapted for testing purposes only from OSBOURNE, Modern Marine Engineer s Manual, Volume I Copyright 1965 by Cornell Maritime Press, Inc. Further reproduction prohibited without permission Page 17 of 25

18 National Maritime Center Providing Credentials to Mariners GS /23/2016 Adapted for testing purposes only from HUNT, Modern Marine Engineer s Manual, Volume II Copyright 2002 by Cornell Maritime Press, Inc. Further reproduction prohibited without permission Page 18 of 25

19 National Maritime Center Providing Credentials to Mariners GS /4/2016 Adapted for testing purposes only from HUBER, Tanker Operations, Fourth Edition Copyright 2001 by Cornell Maritime Press Further reproduction prohibited without permission Page 19 of 25

20 National Maritime Center Providing Credentials to Mariners MO /17/2017 Adapted for testing purposes only from HARRINGTON, Marine Engineering Copyright 1992 by The Society of Naval Architects and Marine Engineers Further reproduction prohibited without permission Page 20 of 25

21 National Maritime Center Providing Credentials to Mariners MO /20/2016 Adapted for testing purposes only Further reproduction prohibited without permission Page 21 of 25

22 National Maritime Center Providing Credentials to Mariners MO /24/2016 Adapted for testing purposes only Further reproduction prohibited without permission Page 22 of 25

23 National Maritime Center Providing Credentials to Mariners SE /8/2016 Adapted for testing purposes only BLANK, Introduction to Naval Engineering, Second Edition Copyright 1985 by the United States Naval Institute Further reproduction prohibited without permission Page 23 of 25

24 National Maritime Center Providing Credentials to Mariners SG /7/2016 Adapted for testing purposes only from Principles of Naval Engineering NAVPERS B Further reproduction prohibited without permission Page 24 of 25

25 National Maritime Center Providing Credentials to Mariners SG /8/2016 Adapted for testing purposes only HARRINGTON, Marine Engineering Copyright 1992 by The Society of Naval Architects and Marine Engineers Further reproduction prohibited without permission Page 25 of 25