National Maritime Center

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1 National Maritime Center Providing Credentials to Mariners U.S.C.G. Merchant Marine Exam (Sample Examination) Page 1 of 26

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. If a slow-speed two-stroke cycle diesel engine is fitted with exhaust valves located in the cylinder heads, what scavenging flow-pattern is utilized? (A) Uniflow scavenging o (B) Loop scavenging o (C) Cross-flow scavenging o (D) Return-flow scavenging 4. 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 Page 2 of 26

3 5. 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. 6. Which of the following is an example of a solid bearing? (A) Piston pin bushing o (B) Turbo-generator turbine bearing o (C) Spring bearing o (D) Thrust bearing 7. The diesel engine component labeled "3", shown in the illustration is called the. Illustration MO-0122 (A) cylinder head o (B) head valve assembly o (C) scavenging air space o (D) cylinder liner 8. Before starting a diesel engine, you should always. o (A) check the pyrometer readings (B) check the crankcase oil level o (C) change the fuel oil strainers o (D) clean the air filter 9. 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 Page 3 of 26

4 10. Which of the following types of bearings are used as line shaft bearings? o (A) tapered roller, split type radial (B) Ring-oiled, Babbitt-faced, spherical seat, shell o (C) Segmental, pivoted-shoe thrust o (D) Rigidly mounted, radial sleeve 11. 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 12. What type of clutch is pictured in the illustration? Illustration MO-0089 o (A) Electromagnetic o (B) Mechanical o (C) Pneumatic (D) Hydraulic 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. 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 Page 4 of 26

5 15. On a medium-speed motor vessel, what is the typical location of the thrust bearing where propeller thrust is transmitted to the ship's hull? o (A) Within the stern tube associated with the tail or propeller shaft as applicable. (B) Within the main reduction gear associated with the bull gear shaft or in an independent thrust block associated with the line shaft. o (C) Within each main engine associated with its crankshaft. o (D) Within a strut associated with the propeller shaft. 16. 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 If choice C is selected set score to 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 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. 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 Page 5 of 26

6 20. The section of the turbocharger which would be connected to the aftercooler inlet is labeled. Illustration MO-0080 o (A) H (B) B o (C) C o (D) K 21. Compared to a naturally aspirated diesel engine, a supercharged diesel engine has. (A) a cylinder air charge of higher pressure o (B) reduced cylinder mean effective pressure o (C) less valve overlap o (D) reduced blow-by 22. 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 23. The possibility of a diesel engine crankcase explosion will be increased by operating an engine. (A) with a leaking crankcase inspection cover gasket o (B) with a crankcase vacuum between 1.5" and 2" of water o (C) equipped with a crankcase exhaust blower which vents to fresh air o (D) in cooler sea water temperatures 24. In an auxiliary diesel engine "bypass type" lubricating oil system, the main lube oil pump forces. (A) some of the oil used by the engine through a filter o (B) some of the oil used by the engine through a centrifuge o (C) all of the oil used by the engine through a filter o (D) all of the oil used by the engine through a centrifuge Page 6 of 26

7 25. 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. 26. 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 27. For a diesel engine, approximately how long can an electric starter motor be operated continuously before damage may begin to occur due to overheating? (A) Not more than 30 seconds o (B) Not more than 60 seconds o (C) Not more than 90 seconds o (D) Overheating the motor cannot occur. 28. 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 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 If choice C is selected set score to 1. Page 7 of 26

8 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 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 32. 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 33. 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 34. 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 Page 8 of 26

9 35. 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 36. An auxiliary turbine boiler feed pump should normally be stopped by. o (A) rotating the hand lube oil pump backwards o (B) increasing the load on the driven unit (C) actuating the throttle hand tripping device o (D) closing the exhaust valve slightly If choice C is selected set score to 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 38. 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. If choice C is selected set score to When a boiler has been secured and is being initially cooled, the water level showing in the steam drum gage glass should be. (A) maintained at the normal level o (B) allowed to drop naturally o (C) maintained at a full glass o (D) allowed to go out of sight Page 9 of 26

10 40. 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 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) ph of the feedwater o (C) speed of the main feed pump o (D) density of the feedwater 42. 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 43. 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 If choice C is selected set score to 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 If choice C is selected set score to 1. Page 10 of 26

11 45. 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 46. 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. 47. 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 48. In the event of a failure of the pneumatic control system, a multi-element feedwater regulator is designed to operate as a. o (A) constant-pressure regulator (B) manually controlled feedwater regulator o (C) constant-volume feedwater regulator o (D) thermo-hydraulic feedwater regulator 49. According to the illustration, bellows "I" in the gland seal regulator is actuated by. Illustration SE-0019 (A) gland seal steam pressure o (B) control air pressure o (C) steam throttle pressure o (D) lube oil pressure Page 11 of 26

12 50. In a gravity lube oil system, a sight glass is installed in a line near the operating platform. This line connects the. (A) gravity tank overflow and the sump o (B) bottom of the gravity tank and the lube oil headers o (C) bottom of the gravity tank and the sump o (D) gravity tank overflow and the lube oil headers 51. What type of lube oil cooler is shown in the illustration? Illustration GS-0122 o (A) Self-venting o (B) Plate type (C) Shell-and-tube o (D) Bundle and stack If choice C is selected set score to The dirty oil inlet on centrifugal lube oil purifiers is located at the. o (A) top of the tubular bowl type o (B) top or bottom of the disk-type depending upon whether the unit is to be operated as a separator or clarifier o (C) bottom only of the disk-type (D) bottom of the tubular bowl type 53. 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 54. 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. Page 12 of 26

13 55. 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 If choice C is selected set score to 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. (A) prevent the external leakage of oil out of the bearing housing o (B) direct the flow of oil through the bearing o (C) ensure efficient lubrication of the bearing o (D) prevent the leakage of main steam into the oil 57. 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 58. A common method of preheating main turbine lube oil prior to rolling over the main unit would be to. o (A) bypass the lube oil gravity tank o (B) slightly increase gland sealing steam pressure (C) operate the lube oil purifier on the main lube oil sump o (D) run both the lube oil pumps simultaneously If choice C is selected set score to 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. If choice C is selected set score to 1. Page 13 of 26

14 60. 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 If choice C is selected set score to 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) Crosshead diesel engine cylinder oil. o (B) Gas turbine lubricating oil. o (C) Trunk type diesel engine lubricating oil. (D) Steam turbine lubricating oil. 63. 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 If choice C is selected set score to 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 Page 14 of 26

15 65. 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 66. 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 67. 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 68. 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 69. Which of the listed devices would be installed at a control system air pressure reducing station? (A) Moisture separator o (B) Non-return valve o (C) Lubricator o (D) Vacuum breaker Page 15 of 26

16 70. 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. If choice C is selected set score to 1. Page 16 of 26

National Maritime Center Providing Credentials to Mariners GS-0070 3/14/2016 Adapted for testing purposes only from OSBOURNE, Modern Marine

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 26

National Maritime Center Providing Credentials to Mariners GS-0116 3/23/2016 Adapted for testing purposes only from HUNT, Modern Marine

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 26

National Maritime Center Providing Credentials to Mariners GS-0122 4/6/2016 Adapted for testing purposes only from Marine Drives, Reverse

19 National Maritime Center Providing Credentials to Mariners GS /6/2016 Adapted for testing purposes only from Marine Drives, Reverse Reduction Series MR Service Manual Copyright by The Falk Corporation Further reproduction prohibited without permission Page 19 of 26

20 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 20 of 26

National Maritime Center Providing Credentials to Mariners MO-0080 7/14/2016 Adapted for testing purposes only from Exhaust-Gas Turbocharger VTR 250

21 National Maritime Center Providing Credentials to Mariners MO /14/2016 Adapted for testing purposes only from Exhaust-Gas Turbocharger VTR 250 W3P, Instructions For Operation and Maintenance Copyright BBC Brown, Boveri & Company, Ltd. Further reproduction prohibited without permission Page 21 of 26

22 National Maritime Center Providing Credentials to Mariners MO-0089 Adapted for testing purposes only from STINSON, Diesel Engineering Handbook, 12 th Edition Copyright 1981 Business Journals, Inc. Further reproduction prohibited without permission. Page 22 of 26 7/25/2016

National Maritime Center Providing Credentials to Mariners MO-0122 9/30/2016 Adapted for testing purposes only from EMD 645E9 Turbocharged

23 National Maritime Center Providing Credentials to Mariners MO /30/2016 Adapted for testing purposes only from EMD 645E9 Turbocharged Engine Maintenance Manual Copyright 1973 Electro-Motive Division, General Motors. Page 23 of 26 Further reproduction prohibited without permission.

National Maritime Center Providing Credentials to Mariners MO-0128 10/20/2016 Adapted

24 National Maritime Center Providing Credentials to Mariners MO /20/2016 Adapted for testing purposes only Further reproduction prohibited without permission Page 24 of 26

National Maritime Center Providing Credentials to Mariners SE-0003 12/8/2016 Adapted for testing purposes only BLANK, Introduction to Naval

25 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 25 of 26

26 National Maritime Center Providing Credentials to Mariners SE /4/2017 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 Page 26 of 26

National Maritime Center

National Maritime Center Providing Credentials to Mariners U.S.C.G. Merchant Marine Exam (Sample Examination) Page 1 of 20 U.S.C.G. Merchant Marine Exam Illustrations: 9 Choose the best answer to the following