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Engine Room Motor Plants II

 

B Why will a turbocharged diesel engine produce black smoke if excessive additional load is applied too quickly? Exhaust energy would draw excess air. The inertia of the turbocharger rotor causes a time lag which delays the turbocharger speed increase. Exhaust gas pumping losses are increased due to turbine windage. Exhaust gas back pressure falls slightly due to increased nozzle action. Air - Charging systems
C After cooling of a turbocharged diesel engine will result in __________. higher torque but lower brake horsepower lower torque but higher brake horsepower higher torque and higher brake horsepower lower torque and lower brake horsepower Air - Charging systems
B The process of scavenging a two-stroke/cycle diesel engine serves to __________. improve fuel flow volume cool the exhaust valves reduce the intake air charge density increase the temperature of exhaust gases Air - Charging systems
D When would the available energy of the exhaust gases of a two-stroke/cycle diesel engine be insufficient to drive an exhaust gas turbocharger, resulting in the incorrect amount of air for combustion? During operation at low load and speed During operation at rated speed, but low power output During acceleration All of the above. Air - Charging systems
C The average exhaust temperature of a two-stroke/cycle diesel engine with a turbine-driven supercharger is lower than a similar four-stroke/cycle diesel engine at equal loads because __________. two-stroke/cycle diesel engines have a higher M.E.P. than four-stroke/cycle diesel engines four-stroke/cycle diesel engine exhaust is cooled by scavenging air two-stroke/cycle diesel engines have a lower M.E.P. than four-stroke/cycle diesel engines the opening of the two-stroke/cycle diesel exhaust ports or valves occurs much later than in four-stroke/cycle diesel engines Air - Charging systems
A Clearance volume scavenging in a turbocharged, four-stroke/cycle diesel engine is accomplished __________. during the valve overlap period with only the exhaust valve open at a pressure below atmospheric without cooling the cylinders or pistons Air - Charging systems
D In a turbocharger, inlet air velocity is increased in the __________. inlet nozzle ring stationary diffuser passages compressor outlet volute rotating impeller vanes Air - Charging systems
D Regarding the turbocharger shown in the illustration, the part labeled "B" would be attached to the __________. Illustration MO-0080 nozzle ring silencer outlet exhaust manifold after cooler inlet Air - Charging systems
D Which of the following statements is correct regarding a turbocharged four-stroke cycle diesel- generator? At zero load the intake manifold pressure is greater than the exhaust manifold pressure. At full load the intake manifold pressure and exhaust manifold pressure are equal. At full load the intake manifold pressure is less than the exhaust manifold pressure. At full load the intake manifold pressure is greater than the exhaust manifold pressure. Air - Charging systems
C Large, two-stroke/cycle, main propulsion, diesel engine cylinders can be successfully pressure charged during normal operation, by using the __________. exhaust gas temperature system exhaust load system constant or pulse pressure system constant volume system Air - Charging systems
C Which of the turbocharging systems listed operates with the least average back pressure in the exhaust manifold? Constant volume Constant pressure Pulse pressure Radial flow Air - Charging systems
A Which of the turbocharging methods listed directs the exhaust gases to the turbine at fairly uniform velocity and pressure? Constant pressure Pulse pressure Constant velocity Axial flow Air - Charging systems
A In a Roots-type rotary blower, the volume of air delivered is directly proportional to __________. engine speed engine load brake horsepower brake specific fuel consumption Air - Charging systems
B Which of the designs listed will keep the lobes from making contact in a Roots-type blower? Drive chain Blower timing gears Air trapped between blower lobes Oil filter between blower lobes Air - Charging systems
A In a two cycle diesel engine, a Roots type blower is usually __________. gear driven by the engine driven by an exhaust gas turbine actuated by the intake valves driven by separate motor Air - Charging systems
C Which of the operating characteristics listed is correct concerning the blower shown in the illustration? Illustration MO-0082 Each of the lobes are in constant contact with each other Air delivery is inversely proportional to engine speed. Air delivery is approximately proportional to engine speed. The blower is driven by engine exhaust gases Air - Charging systems
D The power consumed during the scavenging process of a diesel engine is known as the __________. compression loss valve loss back pressure loss pumping loss Air - Charging systems
C Air scavenging of the cylinder shown in the illustration begins between figures __________. Illustration MO-0025 4 and 5 2 and 3 3 and 4 5 and 6 Air - Charging systems
A 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 __________. effective cylinder scavenging and cooling constant pressure from the turbochargers cooler operation of the exhaust system effective constant pressure for turbocharger operation Air - Charging systems
A A loop or cross scavenged engine utilizes the motion of its pistons and a turbocharger to provide scavenging air. Which of the listed mechanical designs prevents the air under the pistons from being pumped back through the scavenge ports during the piston power stroke? Length of the piston skirt Masked intake ports Lower liner seals Positive pressure from the blower Air - Charging systems
B The diesel engine shown in the illustration, is provided with an auxiliary blower to __________. Illustration MO-0003 increase scavenge air pressure at full load provide scavenge air pressure at low load maintain a vacuum on the crankcase maintain a positive pressure on the crankcase Air - Charging systems
D A diesel generator governor is hunting. After changing the oil, the governor is flushed and the compensation needle valve is adjusted, but the hunting persists. You should NOW __________. check air intake manifold pressure calibrate the fuel pump rack settings set the speed droop adjustment to zero carefully check for binding in the governor linkage Casualty Control
B The most common contaminate of governor hydraulic fluid is __________. moisture dirt acid air Casualty Control
C If a hydraulic governor has been refilled with oil, the engine should be operated until it reaches normal temperature, then the air should be purged, and the __________. rack position should be adjusted compensating needle valve should be opened fully compensating needle valve should be adjusted to stabilize operation speed limiting device should be adjusted Casualty Control
D Adjustments to the compensating needle valve in a hydraulic governor should be made with the engine at __________. maximum power at a normal load maximum power and load under normal conditions half speed and normal temperature normal operating temperature without a load Casualty Control
A Sacrificial zinc anodes are used on the saltwater side of diesel engine heat exchangers to __________. reduce electrolytic action on heat exchanger metals provide a protective coating on heat exchanger surfaces keep heat transfer surfaces shiny and clean prevent rapid accumulation of marine growth Casualty Control
C When the timing gear backlash for a Roots-type blower has become excessive, the problem is properly repaired by __________. renewing the drive gear renewing the driven gear renewing both driving and driven gears as a set shimming and pinning the gears with proper backlash Casualty Control
A Which of the listed effects would mixtures of ethylene glycol and phosphate compounds have on the metal surfaces of the cooling system of a diesel engine? Protects metallic surfaces from corrosion and the coolant from freezing Tends to increase corrosion Increases the rate of heat transfer Retards the flow of cooling water Casualty Control
A Ethylene glycol, when used as a coolant in a closed cooling system for a diesel engine, is more advantageous than untreated raw water because it __________. has a lower freezing point and higher boiling point provides a constant pH below 7 provides better vapor-phase cooling has a higher freezing point and a lower boiling point Casualty Control
B If the coolant temperature is too low as it passes through internally cooled fuel injectors, the injectors can be damaged by __________. water condensation in the fuel corrosion of the nozzle tip decrease in fuel oil viscosity inadequate lubrication of the needle valve Casualty Control
A When installing the bearing cap on the device shown in the illustration, which of the precautions listed must be observed? Illustration MO-0121 Once the bearing cap is properly torqued, measure the end gap dimensions to ascertain even tightening of the cap. If the device is covered with abrasive material or contaminates, the unit may be reassembled, provided an abnormal method of reassembly is followed. Prior to installing the cap, position the thrust shoes in their proper locations. After applying antiseize to the external threads, torque one side at a time to the appropriate values using a quality torque wrench. Casualty Control
C What is the normal bearing clearance permitted at the horizontal axis of the shaft for the bearing shown in the illustration? Illustration MO-0121 The clearance is determined by the thickness of the hydrodynamic wedge formed and is not usually measured while underway. The tolerances established are dependent on machining processes used and will vary
 amongst manufacturers.
The normal play on both sides of the shaft will be one tenth of a millimeter. The clearance on one side of the shaft at the axis will be one twentieth of a millimeter. Casualty Control
B After following the prescribed procedures to measure the thrust bearing clearance shown in the illustration, the distance "F" is determined to be 200 mm, and 'f1' is 2.3 mm. Which of the following statements describes the condition indicated by these dimensions? Illustration MO-0121 These dimensions indicate the presence of flourishing marks on the thrust shoes; the marks becoming visible as the distance at 'f1' increases. It is possible for the shaft to move axially 2.3 mm during astern operation and relates to an excess movement of 1.3 mm, 0.3 mm beyond the maximum worn play. The loading ratio, or shaft diameter divided by collar surface area is within 2.7 : 1. The total active thrust area is 202.3 mm, well within the standards set forth by the GSMA (German Society for Machining Accuracy). Casualty Control
B Because of the close tolerances used in diesel engine fuel oil pumps, a worn plunger requires __________. grinding the spare plunger to the barrel replacing the plunger and the barrel highly polishing both the plunger and barrel replacing plunger only Casualty Control
A When a nozzle tester is being used to test a "closed" type fuel injection nozzle, a clogged nozzle orifice will be indicated by a __________. distorted spray pattern chattering sound when the nozzle closes squealing sound midway in the pump stroke popping sound when the nozzle opens Casualty Control
A Which of the fuel nozzles listed requires the LEAST maintenance? Pintle Single hole Multi-hole Open Casualty Control
A When running a large, dual fuel, main propulsion diesel engine on heavy fuel, which of the following precautions should be observed when switching from heavy fuel oil to diesel oil? The temperature of the fuel from the preheater should be gradually reduced after switching over the three-way valve. The diesel oil must never be allowed to mix with the heavy fuel. The heating steam to the preheater should be increased as soon as the diesel fuel passes through the three-way valve. The heating steam must be secured before the diesel oil passes through the three-way valve. Casualty Control
B Air is normally bled from a diesel engine fuel system by __________. blowing down the air tanks loosening the compression nuts at the injectors changing fuel filters pumping down the day tanks Casualty Control
B The spray holes in diesel engine fuel valves should be cleaned using carbon solvent and __________. diesel fuel a special cleaning wire a copper wire brush a shaved wooden dowel Casualty Control
B If the compression rings on a diesel engine piston become stuck in the ring groove, the cause may be due to __________. excessive ring action excessive ring temperature improper ring rotation excessive ring face wear

Casualty Control
A The insertion of shims between the foot of a marine type connecting rod and a bearing box would result in __________. increased compression ratio decreased compression ratio increased bearing clearance decreased bearing clearance Casualty Control
D After a long period of operation, a wear ridge, caused by piston ring action, will develop near the top of the cylinder liner. This ridge must be removed during maintenance in order to prevent __________. excessive ring wear during the seating period excessive lubrication of the top ring improper coating of lubrication on the cylinder wall breaking of the rings, ring lands, or both during piston removal Casualty Control
D When a piston is removed from a diesel engine for maintenance, the piston should be examined for __________. cracks and burned spots scoring gummy deposits and sticking rings All of the above. Casualty Control
D Excessive side clearance between a piston ring and its groove will cause the ring to __________. expand excessively under operating temperatures scuff the cylinder liner excessively hammer the piston land above the ring hammer the piston land below the ring Casualty Control
D After removing the bowl hood of the device shown in the illustration, excessive quantities of sludge are visible. Which of the following statements represents the approach to rectify
the situation? Illustration MO-0112
Disassemble the entire unit, clean all components, replace all defective discs and use the proper lubricant where required. Steam clean the components in place, check for proper alignment, using the match marks provided, reassemble and restart the unit. Remove only the disc stack, separate all the discs, clean with steel wool and solvent, replace the disc stack ensuring it is located by use of the dowel pin shown. Disassemble the entire unit, clean all components, replace any defective gaskets and use the proper lubricants where required. Casualty Control
C When tightening the lock ring "G" of the device shown in the illustration, two events are simultaneously accomplished. Which of the following statements represents these events? Illustration MO-0112 The lock ring insures proper contact between the bowl top and the sliding bowl bottom, in addition to compressing the disc stack. The lock ring forces the disc stack onto the spindle, providing a positive means of rotation and locating the bowl top to seal the separation chamber. When tightened, the lock ring allows for movement of the sliding piston and positions the sliding piston within the bowl bottom. The lock ring insures proper positioning of the disc stack and maintains a positive contact of the bowl top and bowl bottom. Casualty Control
D Before any auxiliary diesel engine hydraulic starting system is opened for servicing or repair, you must __________. place all control levers in the 'HOLD' position ensure that the hydraulic fluid reservoir is full block all hydraulic hoses using high pressure covers bleed off all hydraulic pressure from the system Casualty Control
B The service life of a worn aluminum piston for an auxiliary diesel, for which no spares are readily available, can be extended by __________. turning down the piston skirt to concentric values knurling the piston skirt surface building up the piston skirt with a liquid epoxy material and then remachining increasing the dimensions of the ring land grooves Casualty Control
A In an auxiliary diesel engine, one reason for knurling the piston skirt is to __________. improve skirt lubrication allow for heat expansion transmit forces evenly improve the piston seal Casualty Control
B Decreasing the exhaust valve clearance of a diesel engine will cause the exhaust valve to open __________. earlier and have less lift earlier and remain open longer later and have greater lift later and have less duration Casualty Control
D When inspecting the valve mechanism shown in the illustration, normal maintenance would include __________. Illustration MO-0074 mechanically adjusting the valve at point "D" mechanically adjusting the valve at point "E" changing the tappet clearance as measured between points "A" and "B" measuring the cold valve clearance between components "C" and "D" Casualty Control
D Which of the following statements would apply when checking the valve clearance of the unit shown in the illustration? Illustration MO-0074 The valve is mechanically adjusted at point "D". The valve is mechanically adjusted at point "E". Tappet clearance is measured between points "A" and "B". Cold valve clearance is measured between components "C" and "D". Casualty Control
C If a tube ruptures in a water-tube auxiliary boiler due to low water, you should __________. secure the fires and maintain feed water to boiler to keep up the water level not secure the fires until water level falls out of sight in the gage glass secure both the fires and the feed inlet valve secure the fires when the pressure drops to 50% of the maximum allowable working pressure Casualty Control
D What is the best way of stopping an over speeding diesel engine? Disconnect the battery cables from the starting motor. Drain the hydraulic fluid from the governor sump. Block the flow of cooling air to the radiator. Secure the fuel supply and block the air intake Casualty Control
C If a crankcase explosion due to a hot spot were to occur, the size of the explosion is dependent on which of the following? The temperature of the hotspot in the crankcase. The amount of debris in the oil in the crankcase. The ratio of oil mist to air in the crankcase. The amount of water in the oil in the crankcase. Casualty Control
D Which of the following oil mist to air ratios would most likely lead to the most severe crankcase explosion? 12-15% by volume. 2-3% by volume. 9-10% by volume. 5-7% by volume. Casualty Control
A In the event of a crankcase rich oil mist to air mixture explosion, where the doors are blown off the engine, which of the following may occur after the initial explosion? A secondary explosion as air is drawn back into the crankcase. The crankcase pressure will remain higher than normal. The engine will over speed. Any crankcase fire will be self extinguished. Casualty Control
D After stopping a diesel engine with a high main bearing temperature, what is the time one needs to wait before a diesel engine crankcase can be opened? Not less than 120 minutes. Not less than 15 minutes. Not less than 60 minutes. Not less than 30 minutes. Casualty Control
B Which of the following is one of the ways to prevent a scavenging fire on a slow speed diesel engine? Prevent air from entering the scavenging space. Keep the scavenging space clean and free of oil. Shut down the engine if the crankcase mist detector alarm sounds. Monitor the main bearing temperatures. Casualty Control
A Oil in a scavenging air space on a slow speed diesel engine can be ignited by which of the following? Excessive piston ring blow by. Burned exhaust valve seat. Hot main bearing. Early fuel injection. Casualty Control
B If a scavenging air space fire occurs on a slow speed diesel engine and the engine is stopped, which of the following should be done to prevent distortion due to heat? Let the fire burn out naturally. Engage and turn the engine with the jacking gear. Open the engine to inspect the hot area. Use CO2 to extinguish the fire and cool the engine. Casualty Control
A Which of the following would indicate a scavenging air fire in a slow speed diesel engine? An increase in jacket water temperature in the area local to the fire. A low main lube oil pressure alarm. An oil mist detector alarm. An increase in main bearing temperature in the area local to the fire. Casualty Control
C If a diesel engine were running at 20% overload with a smoky exhaust, you should __________. stop the engine immediately to prevent damage increase lube oil pressure slow the engine allowing it to gradually cool decrease the cooling water temperature to the water jacket Casualty Control
C A main propulsion diesel engine is normally shutdown by __________. shutting off the air supply over speeding the engine securing the fuel supply securing the ignition system Control Systems
C The over speeding of the diesel engine driving an electric generator could cause __________. low voltage trip to trip reverse power trip to trip damage to the field windings excessive exhaust temperatures Control Systems
C A normally operating diesel engine is shutdown by __________. shutting off the air supply over speeding the engine securing the fuel supply securing the ignition system Control Systems
B Load control on a diesel engine is accomplished by __________. regulating the speed of the turbocharger regulating the amount of fuel admitted to the engine regulating the speed of the fuel oil transfer pump changing engine timing Control Systems
D Diesel engine automated control systems may utilize sensing devices of dual function, with sensing ranges providing both alarm and engine shut down capability. Which of the key points listed would only require an alarm sensor? Lube oil pressure and temperature Jacket water pressure and temperature Engine over speed Lube oil sump level Control Systems
D Which of the following statements describes the operation of the circuit shown in the illustration? Illustration MO-0114 The output of "2" will always be less than the input at "1" by 0.35 bar (35 kPa), to prevent engine damage due to operation in the critical speed range.
 o
A gradual rise of the input signal to "1" will cause a multiple stepped output from "2" proportional to the input signal.
 o
The output signal from "2" will be equal to the set point of '17A' only when the input is less than the set point of '17B', permitting the transition signal to become modulated. The output from "2" is equal to the input to "1" except when the input of "1" is between the set points of '17A' and '17B', when it will remain at the value of '17A'. Control Systems
D The device represented by the symbol "B" in the illustration is used to __________. Illustration MO-0115 remove all moisture from the system
 o
lubricate the air supply reduce the temperature of the air supply as a result of the heat of compression remove most contaminants present in the air supply Control Systems
C The pneumatic circuit shown in the illustration is part of a control system used with large low speed diesel engines. The arrangement may be used to control __________. Illustration MO-0118 bridge tachometer variations the proportional offset of the throttle signal main engine speed
 o
emergency clutching operations Control Systems
D The symbol with the output 'ee' shown in the illustration, is properly called a blocking valve. Which of the following statements describes its function when incorporated into a slow speed diesel engine pneumatic control circuit? Illustration MO-0116 The device is used to interrupt the control signal to port "J" of the air start distributor shown in illustration MO-0053.
The blocking device prevents direct hydraulic flow from operating the reversing mechanism.
All speed signals emanating from the throttle lever are diminished by half due to the blocking effect of this valve. The device is used to interrupt the pneumatic signal to port "A" of the distributor shown in illustration MO-0053. Control Systems
A A water jacket is placed around the exhaust manifolds of propulsion diesel engines to __________. reduce heat radiation to the engine room aid in preventing turbocharger overheating condense and drain moisture from exhaust gases dampen exhaust gas pulsations in the manifold Cooling Systems
D In the engine shown in the illustration, the part labeled 'W' is cooled by __________. Illustration MO-0003 lube oil convection air seawater Cooling Systems
C The diesel engine shown in the illustration, which of the lettered parts listed is cooled by sea water? Illustration MO-0003 P Y W Q Cooling Systems
D The large, slow-speed, main propulsion diesel engine shown in the illustration, the part labeled 'B' contains __________. Illustration MO-0003 exhaust gas oil diesel oil water Cooling Systems
C The outlet from an expansion tank of a closed fresh water cooling system should be piped to the __________. cylinder jacket inlet main heat exchanger inlet connection jacket water pump suction line cylinder head water outlet header Cooling Systems
D Which set of valves will be opened intentionally to remove heat from the main engine jacket cooling water system shown in the illustration? Illustration MO-0111 "G" and "H", "E" and "F" "B" and "D", "L" and "M" "J" and "K", "G" and "H" "A" and "C", "L" and "M" Cooling Systems
B What is the function of the device labeled "3" shown in the illustration? Illustration MO-0111 The device specifically serves to remove the latent heat of vaporization from the jacket water. The cooler removes sensible heat from the jacket water. The heat exchanger serves to heat the jacket water during cold water operation. The jacket water cooler is used to raise the temperature of the sea water flowing through it. Cooling Systems
A What is the function of the item "7" shown in the illustration? Illustration MO-0111 This jacket water pump circulates fresh water throughout the engine cooling and distiller heating systems. This circulating salt water pump will supply feed water for the operation of the distiller. This jacket water pump supplies the distiller with sea water feed while also powering the eductors. This jacket water pump circulates salt water through the jacket water cooling system to provide engine cooling. Cooling Systems
C Fuel injectors used in heavy fuel oil systems are usually provided with cooling to reduce __________. cold corrosion of the nozzles fuel viscosity for better atomization carbon accumulation on the nozzles fuel detonation in the cylinders Cooling Systems
B The operation of the lube oil cooler, shown in the illustration as item #4, will be characterized by which of the following statements? Illustration MO-0111 The temperature of the lube oil entering the cooler will decrease whenever the distiller is on line. The temperature of the sea water entering the cooler will be higher when operating with the distiller on line. The pressure of the lube oil to the cooler will increase whenever the distiller is on line. The pressure of the sea water to the lube oil cooler will increase with the distiller on line. Cooling Systems
D What is the primary function of item '15' shown in the illustration? Illustration MO-0111 It removes the vapor condensed in area "23". It is the chemical cleaning pump used in conjunction with valve "12". It is used to empty the evaporator section when there is tube leakage while the unit is secured. It removes the distillate condensed in area "24". Cooling Systems
D Which of the following statements represents the two major functions provided by the item labeled "20" shown in the illustration? Illustration MO-0111 The pump supplies the motive force to the ejectors and removes the excess distillate. The pump is used to drain the shell when the unit is secured, in addition to powering the ejectors. The pump provides for venting of associated equipment while also powering the ejectors. The pump supplies the motive fluid to the ejectors in addition to supplying the feed water to the distiller. Cooling Systems
D The items labeled "21" and "22", shown in the illustration are used to remove __________. Illustration MO-0111 distillate and non-condensable gases non-condensable gases from two separate sections of the distiller brine and jacket water from the condenser non-condensable gases and brine Cooling Systems
A What occurs within the tubes of the device labeled "23" shown in the illustration? Illustration MO-0111 The feed water flowing through the inside of the tubes is being heated by the jacket water on the outside of the tubes. The heat from the jacket water passing within the tubes is being transferred to the feed water on the outside of the tubes. The heat of combustion from the engine is being transferred azeotropically, adding latent heat to the entering jacket water. The heat being transferred is subliminal, therefore expansion is taking place within the tubes. Cooling Systems
C Which of the following statements describes what will occur to the volume of water vapor as it is exposed to the lower temperatures existing in the device labeled "24" shown in the illustration? Illustration MO-0111 The volume is increased as condensation occurs at the tube surfaces. The volume will increase if the valve labeled "J" is opened excessively, resulting in an
 increase of the distiller absolute pressure.
The volume is greatly reduced, contributing to condensation within the condenser. The latent heat of condensation is removed causing the volume to increase. Cooling Systems
C Device "27" shown in the illustration is used to __________. Illustration MO-0111 purge the unit of non-condensable gases add de-scaling chemicals as needed regulate maximum vacuum during normal operation relieve excess pressure Cooling Systems
D Which of the valve arrangements listed would be correct for operating the distillation plant shown in the illustration? Illustration MO-0111 Valves "C", "J", "K", "L", "M" open, valves "A", "B", "D", and "H" closed. Valves "H", "J", "K", "L", "M" open, valve "D" closed. Valves "D", "H", "J", "K", "L", "M" open, valves "I", "G", "F", and "E" closed. Valves "J", "K", "L", "M" open, valves "D" and "H" closed. Cooling Systems
C Excess brine accumulated in the distiller, shown in the illustration, is removed during normal operation by __________. Illustration MO-0111 the hydrokineter labeled "21" opening the drain valve located to the left of orifice "19" the continuous action of ejector "22" orifice "19" regulating the amount of feed water entering the distiller, thereby preventing excess brine accumulation Cooling Systems
B During operation which device listed removes air and non-condensable gases from the unit shown in the illustration? Illustration MO-0111 "22" "21" "25" "27" Cooling Systems
A The graphic dotted line between items "27", "12", "9", and "20", shown in the illustration, is used to indicate the use of __________. Illustration MO-0111 electrical conduits and circuitry thermal venting devices ambient venting devices single wire controls Cooling Systems
B Excluding line losses, how many distinct pressure drops will occur as sea water flows through all the heat exchangers in the cooling system shown in the illustration? Illustration MO-0111 6 5 3 4 Cooling Systems
C Which device is used to prevent over pressurization of the illustrated distiller? Illustration MO-0111 "19" "12" "26" "13" Cooling Systems
D Where is the latent heat obtained to create vapor from the feed water in the illustrated distiller? Illustration MO-0111 While it is in contact with device "24". During its contact period with heat exchanger "3". Only as it passes through device "20". From having passed through "23". Cooling Systems
A Which of the following statements describes the approximate relation between the feed water entering the unit shown in the illustration and brine being removed? Illustration MO-0111 Seventy-five percent of the feed water entering the unit is removed as brine. The brine will be removed at a faster rate than feed water entering to prevent the possibility of flooding. Twenty-five percent of the feed water entering the device is removed as brine. The amount of feed water entering the distiller is dependent upon the condition of device "7", while the amount of brine leaving is dependent upon the condition of device "21". Cooling Systems
C Item "10" shown in the illustration is used to __________. Illustration MO-0111 regulate flow from the drain pump prevent damage to device "9" by reducing turbulence direct the flow from the distillate pump cancel the effects of improper regulation developed by device "11" Cooling Systems
D Cooling water pumps driven by direct-reversing diesel engines are usually __________. curved impeller vane with concentric outlet straight impeller vane with tangential housing curved impeller vane with tangential outlet straight impeller vane with concentric housing Cooling Systems
D As a general rule, what would be the recommended operating water jacket outlet temperature range for medium speed marine diesels set up with closed treated fresh water cooling systems and fitted with vented expansion tanks? 105 to 120F 135 to 150F 195 to 215F 165 to 180F Cooling Systems
D In a diesel engine closed freshwater cooling system, the cooling water pressure drop through the engine is 10 psig, and the pressure drop through the heat exchanger is 4 psig at maximum flow rates. The cooling water pump must produce a discharge head of at least __________. 4 psig 6 psig 28.7 psig 15 psig Cooling Systems
A In a diesel engine jacket water cooler, with sea water cooling the fresh water, the __________. jacket water pressure should always be greater than the sea water pressure jacket water pressure must always be less than the sea water pressure jacket water temperature must always be less than 60F sea water temperature must never be warmer than 40F Cooling Systems
D In a diesel engine closed freshwater cooling system employing a radiator, proper water temperature can be obtained by __________. passing cooling water through a space heater passing cooling water through the lube oil cooler piping exhaust gases across the radiator front adjusting the radiator louvers Cooling Systems
B If the jacket water temperature rises rapidly above normal in a diesel engine, you should FIRST __________. clean sea water strainer reduce engine load call the chief engineer check thermostatic valve Cooling Systems
C The expansion tank for a diesel engine closed cooling system is designed to maintain a constant head on the system and __________. provide an air cushion reduce water turbulence allow for an increase in water volume as the engine warms up reduce water temperature Cooling Systems
B The temperature at which an adjustable bellows type thermostatic valve operates is determined by __________. varying air loading pressure to the bellows changing the spring compression opposing the bellows changing the position of the actuating bulb replacing the bellows with a heavier spring Cooling Systems
D The thermostatic valve in the illustration is used for controlling the coolant temperature in a main propulsion diesel engine. Which of the following can be used to verify proper valve operation with the valve disassembled? Illustration MO-0079 Check spring compression values against data given in manufacturer's handbook. Chemically analyze contents of power pellet. Remove and examine the contents of the power pellet. Place the thermostatic element in a container of water at various operating temperatures and note the movement of the valve stem. Cooling Systems
A Diesel engine jacket water is used in the fresh water distillation process as the __________. means of heating the feed water primary means of producing a vacuum within the distiller coolant for the distillate coolant for the brine cooler Cooling Systems
A A three-way thermostatic control valve regulates the diesel engine cooling water temperature by passing a portion of the water __________. around the cooler around the engine overboard to the expansion tank Cooling Systems
C What would be considered a normal temperature increase between the inlet and outlet jacket cooling water of a medium or high-speed diesel engine operating at normal load? 1 to 5F 50 to 100F 10 to 20F 5 to 10F Cooling Systems
A Which operating parameter may need to be decreased when running a large main propulsion diesel engine at low load conditions? Cooling water flow through after coolers Control air supply pressure Lube oil temperature Fuel injection pressure Cooling Systems
C Using a cooling water temperature of 225F (107.2C), instead of 180F (82.2C) in an auxiliary diesel engine, will __________. reduce the probability of scale formation in the jacket cooling passages increase fuel consumption per horsepower hour reduce the opportunity for the formation of sulfuric acid in the cylinder bore exhaust passages allow for smaller water passages within the engine Cooling Systems
B Which of the types of reduction gearing listed is best suited for medium speed main propulsion units? Hypoid Helical Cyclical Spur Drive Systems
C In the reversing reduction gear shown in the illustration, the forward and reverse main pinions are in constant mesh with the main gear. This means the __________. Illustration MO-0085 synchromesh coupling will maintain transition torque control set that is clutched in will rotate as idlers driven from the main gear idling gears rotate in a direction opposite to their rotation when carrying load clutches are engaged by a reduction in control air pressure Drive Systems
B Reduction gear casings are vented in order to __________. allow windage to exist for cooling the gears avoid a buildup of pressure within the gear case minimize lube oil foaming within the case allow for axial clearance between the gears Drive Systems
B A diesel engine with a full speed of 1000 RPM drives a propeller at 300 RPM. What is the speed reduction ratio? 0.3 to 1 3.33 to 1 33 to 1 300 to 1 Drive Systems
D The main engine thrust bearing shown in the illustration contains how many thrust shoes? Illustration MO-0121 20 10 6 12 Drive Systems
D How is lubrication provided to the device shown in the illustration? Illustration MO-0120 The lubrication system closely resembles the system used with standard line shaft bearings.
A separate system containing oil under extremely high pressure is used due to its ability to provide a high film strength.
 o
Only silicate ester based synthetic oils have the capability and necessary characteristics to be used in this type of application. The lube oil enters through the supply pipes shown as #11 and eventually drains to the main engine sump. Drive Systems
D What type of bearing is shown in the illustration? Illustration MO-0120 Axial/radial bearing
Collar bearing Kingsbury thrust bearing Michell bearing Drive Systems
B What prevents the thrust bearing blocks shown in the illustration from rotating within the housing? Illustration MO-0120 The bearing blocks are massive and their weight provides sufficient force to prevent rotation. Found within the thrust bearing cap or cover are extended protrusions to position the thrust shoe segments and maintain minimum clearance.
The bearing assembly is specifically designed to allow for rotation, permitting the transmittal of axial forces across a greater surface area and minimizing loading densities.
The thrust shoes are dove-tailed into the collar. Drive Systems
B Which of the couplings listed is normally not repairable, and is usually replaced if completely damaged? Flexible disk-ring coupling Gear-type coupling Block and jaw coupling Grid spring coupling Drive Systems
D When installing the bearing cap on the device shown in the illustration, which of the precautions listed must be observed? Illustration MO-0121 Prior to installing the cap, position the thrust shoes in their proper locations. If the device is covered with abrasive material or contaminates, the unit may be reassembled, provided an abnormal method of reassembly is followed. After applying antiseize to the external threads, torque one side at a time to the appropriate values using a quality torque wrench. Once the bearing cap is properly torqued, measure the end gap dimensions to ascertain even tightening of the cap. Drive Systems
A What is the maximum allowable clearance permitted between the bearing, shown in the illustration and the shaft along its vertical axis? Illustration MO-0121 0.80 mm 0.30 mm 1.00 mm 0.46 mm Drive Systems
B What is the normal bearing clearance permitted at the horizontal axis of the shaft for the bearing shown in the illustration? Illustration MO-0121 The tolerances established are dependent on machining processes used and will vary
amongst manufacturers.
The normal play on both sides of the shaft will be one tenth of a millimeter. The clearance on one side of the shaft at the axis will be one twentieth of a millimeter. The clearance is determined by the thickness of the hydrodynamic wedge formed and is not usually measured while underway. Drive Systems
C After following the prescribed procedures to measure the thrust bearing clearance shown in the illustration, the distance "F" is determined to be 200 mm, and 'f1' is 2.3 mm. Which of the following statements describes the condition indicated by these dimensions? Illustration MO-0121 The loading ratio, or shaft diameter divided by collar surface area is within 2.7 : 1. These dimensions indicate the presence of flourishing marks on the thrust shoes; the marks becoming visible as the distance at 'f1' increases. It is possible for the shaft to move axially 2.3 mm during astern operation and relates to an excess movement of 1.3 mm, 0.3 mm beyond the maximum worn play. The total active thrust area is 202.3 mm, well within the standards set forth by the GSMA (German Society for Machining Accuracy). Drive Systems
D When an additional load is applied to a diesel engine which is using an inadequately inflated air bladder clutch unit, you can expect __________. excessive wear on the thrust bearings pneumatic seizure chipped reduction gear teeth overheating because of slipping shoes Drive Systems
C Misalignment of the drive shaft and propeller shaft flanges can be detected by using a dial indicator or __________. inside micrometer sighting device feeler gage adjustable trammel Drive Systems
C The gear drive, shown in the illustration, can have the backlash determined best by using a __________. Illustration MO-0091 lead wire red dye indicator feeler gauge lash indicator Drive Systems
B The thrust bearing shown in the illustration has over eight years of ahead running time. Measurements show "i1" is 4 mm and "i2" is 1mm. Which of the following conditions is indicated and what steps should be taken, if any? Illustration MO-0121 The stops in which the thrust bearing block rides are worn, and it is necessary to return these to their original specifications. No appreciable wear has occurred, and the proper maintenance procedures should continue to be followed. A wear rate of 1.6 mm per year is excessive and requires immediate assistance from the manufacturer's field support. A wear rate of 1.6 mm per year occurred. Although not excessive, this condition may require more frequent monitoring. Drive Systems
D The power consumed during the scavenging process of a diesel engine is known as the __________. compression loss valve loss back pressure loss pumping loss Exhaust systems
B The exhaust system for a turbocharged diesel engine functions to __________. power the after coolers power the turbocharger reduce the cylinder scavenge effect cool the turbocharger Exhaust systems
C Exhaust pipes for separate main propulsion diesel engines can be combined only when __________. space limitations prevent separately run pipes the engines are small auxiliary units they are arranged to prevent gas backflow to each engine a waste heat boiler is installed Exhaust systems
B One of the factors limiting the amount of load which can be put on a modern marine diesel engine is the __________. governor sensitivity exhaust temperature fuel injection pressure speed of the cam shaft Exhaust systems
B In a diesel engine exhaust system, the cooling of the exhaust gases below their dew point, will result in __________. increased engine back pressure sulfuric acid corrosion surface pitting of the turbocharger compressor blades moisture impingement on the turbocharger compressor blading Exhaust systems
D The most common instrument used to measure diesel engine exhaust pressure is the __________. pyrometer bourdon gauge pneumercator manometer Exhaust systems
C Which of the diesel engine exhaust mufflers listed is usually equipped with a spark arrestor? A wet-type exhaust muffler A constant pressure muffler A dry-type exhaust muffler A constant velocity muffler Exhaust systems
C Diesel engines driving alternators operating in parallel must maintain a set frequency regardless of load changes. The governor characteristic used to accomplish this is known as __________. actuation sensitivity compensation promptness Governors
D The device used to limit engine torque at various engine speeds is called a __________. speed limiting governor variable speed governor constant speed governor load limiting governor Governors
C Sensitivity for a diesel engine governor is described as the __________. governor's speed droop response to variations in engine load ability to maintain desired engine speed without speed fluctuation percent of speed change necessary for corrective action by the fuel control ability to maintain constant speed regardless of engine load Governors
D The principal characteristic of an isochronous governor is it will __________. slow the machine down as the load is increased shut down the engine if it over speeds display excessive speed droop maintain a constant speed with variations of load Governors
B Diesel engine control can be obtained by the bridge __________. at any time only after the engine room control station is switched to 'bridge control' whenever the secondary station is switched to 'bridge control' with the approval of the chief engineer only Governors
B Direct reversible main propulsion diesel engines would normally be fitted with a/an __________. constant speed governor variable speed governor isochronous hunting governor nutating disk governor Governors
B The direct acting mechanical governor used with some small diesel engines, controls fuel flow to the engine by __________. governor flyweight action on a pilot valve which controls fuel injection governor flyweight motion acting on fuel controls through suitable linkage positioning a butterfly valve in the fuel delivery system positioning a servomotor piston attached to the fuel controls Governors
C The function of the synchronizing motor on the generator governor illustrated is to __________. Illustration MO-0092 drive the terminal shaft at a set speed turn the governor drive shaft during start-up provide remote control for speed adjustment power the generator synchronizing lamps Governors
B The governor, shown in the illustration, will have its preset speed droop altered whenever __________. Illustration MO-0092 the speeder spring tension is changed the speed droop lever fulcrum is changed the compensating lever fulcrum is changed All of the above. Governors
A As the load is being decreased on the engine controlled by the governor shown in the illustration, the __________. Illustration MO-0092 right hand end of the floating lever will move up speeder rod will move down pilot valve plunger will move down oil pressure under the power piston will increase Governors
C In a simple hydraulic governor with speed droop, oil under pressure is maintained ready for use in the __________. power piston governor sump spring-loaded piston accumulator pressure pilot valve assembly Governors
C The purpose of the compensating adjustment used in a diesel engine hydraulic governor is to __________. compensate for low oil level increase governor promptness prevent governor hunting limit engine load Governors
B Which of the following statements is correct concerning the operating function of the governor shown in the illustration? Illustration MO-0096 The dial type adjusting knob (B) is used for setting speed droop and damping out hunting. Excess oil under high pressure is released from the spring loaded accumulators to the sump. The speed droop lever spring prevents the engine from racing or hunting by arresting the movement of the power piston after a speed change. The compensating mechanism provides positive control to lower engine speed as load is increased. Governors
C If governor Item #19 in the illustration were to break on a diesel engine operating under full load, the engine RPM will __________. Illustration MO-0095 increase until the over speed trip actuated hunt until stabilized by droop rod decrease to a slightly lower value remain the same until manually changed Governors
B In the illustrated auxiliary diesel engine governor, decreasing the distance between piece #6 and piece #10 will affect the engine by __________. Illustration MO-0094 decreasing the speed increasing the speed increasing the speed droop setting decreasing the over speed trip setting Governors
B The reversing cams of some four-stroke/cycle diesel engines are brought into position by __________. moving the idler sprockets in the drive chain sliding the camshaft along its axis rotating the cam followers 180 rotating the cam 180 Governors and Control Systems
D What is the primary purpose of the pneumatic component shown in the illustration? Illustration MO-0119 If the locking handle is in any position other than 'zero', the output of the pneumatic valve will equal the input. The indicated valve prevents transmission of transient signals to the governor speeder spring. The valve with finite positioning is used to segregate terminal signals originated by the governor whenever the throttle is repositioned. If the throttle is manually moved from its 'zero' position, the resulting effect will tend to override the output of the governor, and secure the air to the control circuit. Governors and Control Systems
C The pneumatic circuit shown in the illustration is part of a complex large low speed engine control system. Which of the following statements describes the function of this circuit? Illustration MO-0117 The circuit shown is used to shift the cam shaft position when reversing the engine. The piston labeled A provides a low pressure signal to the other components illustrated. Valve D, when depressed, allows the retained pneumatic pressure within the shut-down servo motor to be relieved. When oil pressure to valve C is diminished, a pressure decrease is developed at valve D, causing it to shift, and nullifying the actuating signal to device A. Governors and Control Systems
A If the input signal rises above the set point of '17A', shown in the illustration, but remains below the set point of '17B', the output from '22A' will __________. Illustration MO-0114 indicate a pressure on '67B' equal to the set point of '17A' be the same as the set point of '17B' indicate a pressure on '67A' equal to the input of '17A' improve to a steady state when moisture is removed from the system Governors and Control Systems
B The circuit shown in the illustration represents a/an __________. Illustration MO-0115 infinitely positioned pneumatic control detented, control air pressure, reducing and filtering unit pneumatic actuated, multiple position, control unit hydraulic actuated, multi-position control unit Governors and Control Systems
B Which of the operating positions, for valve "A" shown in the illustration, should be chosen to maintain the circuit in continuous flow, regardless of failure to the included downstream components? Illustration MO-0115 1 2 3 4 Governors and Control Systems
B Which of the following statements describes the function of the device labeled "C" shown in the illustration? Illustration MO-0115 The device is a relief valve with feedback to prevent excessive pressure from damaging system components. The regulator, or pressure reducer, drops the supply pressure to the desired operating level. The regulator reduces the pressure of the supply air to provide ancillary main engine services. Constant pressure is maintained at device "B" while device "C" is used only to modify the output signal. Governors and Control Systems
C Which of the following statements describes the primary reason for the device shown in the illustration to be incorporated into the air start system? Illustration MO-0116 This unit controls the air operated turning motor exhaust when the unit is in operation. The three position valve prevents the fuel flow reaching the fuel injection pumps. The unit shown is used to prevent starting of the main engine when the turning gear is engaged. The shuttle valve compensates for any decrease in the operator's physical abilities. Governors and Control Systems
B A propulsion engine, using the speed control circuit shown in the illustration, fails to function at speeds lower than the low end of the critical speed range. Which of the following statements describes what should be done to correct this malfunction? Illustration MO-0114 To increase the critical speed range of the engine, reduce the setpoint of 17A and 17B respectively, to 0.80 bar and 1.0 bar. Device 17A needs to be replaced, repaired, or reset to the setpoint coinciding with the RPM value for the low end of the critical speed range. The critical speed range will be varied as the setpoints of 17A or 17B are reset, therefore, another segment of the speed control circuit must be repaired. Both 17A and 17B need to be reset to decrease the critical speed range, although this procedure will increase the operating range of the engine. Governors and Control Systems
C A diesel engine operates erratically, over speeds, and fails to restart when cranked at normal speed. Which of the following problems is the most likely cause for the engine failing to restart? Failure to reposition the fuel rack Improper governor operation due to excess oil pressure Failure to reset the over speed trip Damage to the governor due to excessive speed Governors and Control Systems
B A propulsion engine, using the speed control circuit shown in the illustration, fails to function at speeds lower than the low end of the critical speed range. Which of the following statements describes what should be done to correct this malfunction? Illustration MO-0114 To increase the critical speed range of the engine, reduce the set point of 17A and 17B respectively, to .80 bar and 1.0 bar. Device 17A needs to be replaced, repaired, or reset to the set point coinciding with the RPM value for the low end of the critical speed range. The critical speed range will be varied as the set points of 17A or 17B are reset, therefore, another segment of the speed control circuit must be repaired. Both 17A and 17B need to be reset to decrease the critical speed range, although this procedure will increase the operating range of the engine. Governors and Control Systems
B The governor utilized with the device shown in the illustration has become inoperative while the vessel is underway at sea. Which of the following statements describes what action should be taken? Illustration MO-0119 The linkage to the shut down servomotor and the governor output shaft must be disconnected in order to operate the engine via the fuel control lever. The engine speed can be controlled using the fuel control lever without changing the position of the maximum fuel stop. It is necessary to disconnect the shuttle valve from the throttle lever horizontal bar, in order to effectively jump out the pneumatic engine enable control circuit. The governor should be replaced with one that has been proven to be useful in isochronous applications. Governors and Control Systems
D Direct reversible main propulsion diesel engines would normally be fitted with a/an __________. isochronous hunting governor constant speed governor nutating disk governor variable speed governor Governors and Control Systems
C The direct acting mechanical governor used with some small diesel engines, controls fuel flow to the engine by __________. positioning a servomotor piston attached to the fuel controls governor flyweight action on a pilot valve which controls fuel injection governor flyweight motion acting on fuel controls through suitable linkage positioning a butterfly valve in the fuel delivery system Governors and Control Systems
B The governor for an emergency diesel generator is shown in the illustration. When a large change in load results in a change in engine speed, which of the parts listed will be the FIRST governor component to react to the change in load? Illustration MO-0094 Piece #8 Piece #9 Piece #13 Piece #21 Governors and Control Systems
A Increasing the oil pressure acting on the power piston of the hydraulic governor shown in the illustration will __________. Illustration MO-0092 increase the governor output power decrease the speed droop require the over speed trip setting to be adjusted increase the speed droop Governors and Control Systems
D The purpose of the compensating adjustment used in a diesel engine hydraulic governor is to __________. compensate for low oil level increase governor promptness limit engine load prevent governor hunting Governors and Control Systems
C A schematic diagram of an isochronous hydraulic governor is shown in the illustration. When the load is removed the speed increases, and the____________. Illustration MO-0100 balance piston (piece 22) moves downward flyweights (piece 8 and 9) move inward and the pilot valve (piece 10) moves downward pilot valve (piece 10) moves upward proportioner piston (piece 25) moves upward Governors and Control Systems
A Which of the following statements is correct concerning the operating function of the governor shown in the illustration? Illustration MO-0096 Excess oil under high pressure is released from the spring loaded accumulators to the sump. The speed droop lever spring prevents the engine from racing or hunting by arresting the movement of the power piston after a speed change. The dial type adjusting knob (B) is used for setting speed droop and damping out hunting. The compensating mechanism provides positive control to lower engine speed as load is increased. Governors and Control Systems
C A diesel generator governor is hunting. After changing the oil, the governor is flushed and the compensation needle valve is adjusted, but the hunting persists. You should NOW __________. set the speed droop adjustment to zero calibrate the fuel pump rack settings carefully check for binding in the governor linkage check air intake manifold pressure Governors and Control Systems
D The most common contaminate of governor hydraulic fluid is __________. air acid moisture dirt Governors and Control Systems
A If the compensating needle valve of a hydraulic governor is opened more than necessary the governor will __________. produce excessive speed response to a load change stabilize engine speed at the new governor setting have a larger than normal dead band respond slowly to any change in engine load Governors and Control Systems
B A large change in ambient temperature, or using an oil of a viscosity different than the one recommended by the manufacturer in a mechanical hydraulic governor, will result in the need to adjust the __________. accumulator spring tension compensating needle valve pilot valve opening compensating spring tension Governors and Control Systems
C Adjustments to the compensating needle valve in a hydraulic governor should be made with the engine at __________. half speed and normal temperature maximum power at a normal load normal operating temperature without a load maximum power and load under normal conditions Governors and Control Systems
C If the speeder spring of a main propulsion diesel engine governor breaks while operating at full load, the engine RPM will __________. hunt until stabilized by the droop rod increase until the over speed trip actuated decrease to a slightly lower value remain the same until manually changed Governors and Control Systems
A The hunting of a diesel engine may be caused by __________. low governor power excessive speed droop excessive sensitivity insufficient speed droop Governors and Control Systems
A Governor hunting is caused by __________. governor over-control excessive speed droop insufficient speed droop governor under-control Governors and Control Systems
A If the operating speed of a diesel engine increases without an apparent change in the engine control settings, you may suspect a __________. malfunctioning governor leaking air starting valve control air leak clogged intake air intercooler Governors and Control Systems
D Cooling the intake air supplied to a diesel engine will __________. reduce mean effective pressure decrease average compression ratio decrease air charge density increase peak power output Intake and Exhaust Systems
C A large, low-speed, main propulsion diesel engine uses sea water to directly cool the __________. cylinder heads exhaust valves scavenging air injectors Intake and Exhaust Systems
C An increase in the air inlet manifold pressure of a diesel engine will result in a/an __________. decrease in maximum cylinder pressure increase in ignition lag decrease in fuel consumption per horsepower-hour decrease in exhaust manifold pressure Intake and Exhaust Systems
B In a naturally aspirated diesel engine, the volume of air intake is directly associated with engine __________. compression ratio displacement fuel pressure cylinder clearance volume Intake and Exhaust Systems
D What is the function of the after coolers installed in the diesel engine air intake system? Decrease the air density Increase the exhaust temperature Decrease the lube oil temperature Increase the air density Intake and Exhaust Systems
C The section of the turbocharger which would be connected to the aftercooler inlet is labeled __________. Illustration MO-0080 C H B K Intake and Exhaust Systems
A Item labeled "L" as shown in section 6 of the illustration is identified as the __________. Illustration MO-0025 after cooler non return scavenge valve air filter exhaust manifold Intake and Exhaust Systems
B Which of the air intake systems listed will result in the lowest specific fuel consumption? Natural aspiration Turbocharged Roots blower Piston blower Intake and Exhaust Systems
A Compared to a naturally aspirated diesel engine, a supercharged diesel engine has __________. a cylinder air charge of higher pressure reduced cylinder mean effective pressure less valve overlap reduced blow-by Intake and Exhaust Systems
A A naturally aspirated diesel engine at full throttle will have an intake manifold pressure __________. slightly less than atmospheric pressure approximately equal to exhaust manifold pressure at all times that is widely fluctuating constantly decreasing as engine load increases Intake and Exhaust Systems
B In accordance with Coast Guard Regulations (46 CFR Part 112), which of the listed starting aids is acceptable for use with the emergency diesel generator? Injection of ether into the air intake. Thermostatically controlled electric water jacket heater. Thermostatically controlled electric oil sump heater. Heating the starting battery. Regulations
D What device is installed and used as a safety feature to satisfy Coast Guard regulations for the unit shown in the illustration? Illustration MO-0116 Spring clutch Overrunning clutch Pneumatic three position valve Electrical limit switch Regulations
A Coast Guard Regulations (46 CFR Part 56) require steel tubing connections and fittings used with diesel fuel oil systems, to be either flared or __________. of the flareless nonbite type silver soldered have welded flanges have seal-welded threads Regulations
A In accordance with 46 CFR Part 46, diesel fuel oil system valves for removing water or impurities are __________.

"Watch out for this one. I believe it should be Part 56 not 46."
permitted, provided they are fitted with caps or plugs required, if there are no separators installed on board not required, provided there is a high and low tank suction strictly prohibited Regulations
D Before any work is done on a burner in an automatically fired auxiliary boiler, you should always __________. block all control valves allow the boiler to cool completely lock all safety interlock switches closed close all manually operated fuel valves Safety
C Before any work is to be carried out on a burner in an automatically fired auxiliary boiler, you should always __________. block all control system relays closed allow the boiler to cool completely close all manually operated fuel valves lock all safety interlock switches closed Safety
B The starter control valve in the hydraulic system shown in the illustration is malfunctioning. Before removing the valve, you must first __________. Illustration MO-0049 drain the reservoir bleed off all accumulator pressure in "E" remove all plugs from the system ensure that the accumulator piston is in the charged position Safety
A Which of the listed items should be secured before performing any maintenance on a solenoid operated air start valve? Electric power and starting air Lube oil standby pump and control air Hydraulic switch and engage jacking gear Motor drain and pneumatic control system power Safety
A If a diesel engine has been stopped because of piston seizure due to severe overheating, the crankcase __________. inspection covers should not be opened until the engine has cooled ventilation system should be continued in operation for one hour for cooling scavenge pump should be immediately secured to prevent loss of lube oil explosion covers should be opened slightly to provide extra ventilation Safety
A When cleaning a duplex strainer, it is important for __________. the pressure to be bled prior to opening the compartment cover the lube oil to be allowed to cool before removing the basket the cleaning fluid viscosity to be more viscous than the lube oil a new cover gasket to be installed when reassembling the unit Safety
D When a nozzle tester is used to check the spray pattern of a diesel fuel injection nozzle, which of the following statements is true? The valve should normally begin to open at 1/2 the popping pressure The needle valve spring should always be removed first before testing The needle valve should remain open after the nozzle pops open A serious hazard of blood poisoning exists if the fuel spray penetrates the skin of the operator Safety
D The principal hazard to personnel when using a diesel engine fuel nozzle tester is __________. electrical shock toxic fumes explosion blood poisoning Safety
B An immediate repair is required if a leak occurs in the high pressure fuel piping between the injection pump and fuel nozzle because of the __________. high cost of fuel serious fire hazard pollution hazard poor combustion which will occur in that cylinder Safety
D Which of the following precautions should be taken when cleaning the air filter on a diesel engine equipped with a turbocharger? Reduce engine speed to idle before removing the filter. Soak the dirty filter in kerosene only. Blow out the air inlet with compressed air. With the engine stopped, cover the air inlet after removing the filter. Safety
D Following the failure of one turbocharger on a large, crosshead, main propulsion diesel engine, fitted with multiple turbochargers, which of the following actions should be taken prior to further operation of the engine? Blank off the exhaust gas inlet to the damaged turbocharger. Secure cooling and lubrication to the damaged turbocharger. Lock the rotor of the damaged turbocharger. All of the above. Safety
A The gage glass on a coil-type auxiliary boiler is connected to the __________. accumulator surge chamber heating coil inlet and outlet water softener Steam Systems
B Downcomers installed on auxiliary package boilers are protected from direct contact with hot gases by __________. steel baffles refractory and insulation water wall tubes several rows of screen tubes Steam Systems
C Which of the following statements concerning fire-tube boilers is correct? Flames impinge on the tubes. Water flows through the tubes. Combustion gases flow through the tubes. Combustion occurs in the tubes. Steam Systems
A The boiler shown in the illustration would be classed as __________. Illustration MO-0064 single-pass, fire-tube, scotch marine forced circulation, coil-type two-pass, scotch marine two-pass, water-tube Steam Systems
A Which of the listed problems will happen when the water level of a fire-tube type auxiliary boiler approaches the crown sheet? The fusible plugs will melt. The furnace will explode. The furnace will overheat. Excess steam will be generated. Steam Systems
A When preparing to light off a cold boiler equipped with a return flow fuel oil system, the recirculating valve directs the flow of oil __________. back to the suction side of the service pump directly to the fuel oil heater inlet for further warm-up directly to the deep tanks back to the fuel oil settler for further filtration Steam Systems
A Why should the main steam stop valve of an auxiliary boiler be eased off its seat and then gently closed before lighting off? To ensure that the valve will not be seized shut when hot. To check the valve packing. To check for a tight bonnet seal. To examine the valve stem for scars or nicks. Steam Systems
B Which of the automatic boiler controls listed should be tested prior to lighting off an auxiliary boiler? Voltage output of the ignition transformer Low water level cutoff switch Automatic bottom blow valve Insulation resistance readings in the ignition system high tension leads Steam Systems
B As shown in the illustration, the function of component "1" is to __________. Illustration MO-0128 generate superheated steam to operate the turbo generator evaporate circulating boiler water into saturated steam condense excess steam produced in the boiler maintain a water level in the steam drum Steam Systems
B As shown in the illustration, what component would normally be installed at location "D"? Illustration MO-0128 Boiler soot blower unit Oil fired mechanical burner Boiler water level indicator Flue gas smoke indicator Steam Systems
A As shown in the illustration, the component labeled 'E' would be identified as a __________. Illustration MO-0128 waste heat boiler circulating pump boiler water feed pump main condensate pump fuel oil service pump Steam Systems
C As shown in the illustration, the component labeled "H" would be identified as a __________. Illustration MO-0128 waste heat boiler circulating pump fuel oil service pump main condensate pump boiler water feed pump Steam Systems
B In general, diesel engine waste heat boiler construction is usually of the __________. dry back boiler type water-tube type critical circulation boiler type cyclone furnace boiler type Steam Systems
B The purpose of designing some waste heat boilers with sinuous fire tubes, is to __________. reduce accumulations of carbon deposits on the heat transfer surfaces increase the rate of heat transfer to the waterside increase exhaust gas velocity through the boiler eliminate exhaust gas pulsations and noise Steam Systems
B An exhaust gas bypass is installed on a waste heat boiler in order to __________. bypass a portion of the exhaust gas at peak loads for better efficiency minimize moisture condensation in the boiler gas passages at low loads bypass exhaust gas at high loads to prevent excessive back pressure recycle exhaust gas to the turbocharger Steam Systems
D Which of the following is necessary for all waste heat boiler installations, regardless of design or manufacturer? Installation of a superheater An independent means to prevent feed water contamination Installation of a powered circulating booster pump A means to control of evaporation Steam Systems
A With which of the following types of diesel engine arrangements is a waste heat boiler most likely to produce the maximum steam pressure, temperature, and flow conditions? Supercharged, four-stroke/cycle diesel engine Supercharged, loop scavenged diesel engine Turbocharged, cross flow scavenged diesel engine Turbocharged, return flow diesel engine Steam Systems
A Waste heat boilers may be equipped with vents on the feedwater heater heads to __________. prevent air binding release excess pressure allow for feedwater treatment remove sediment Steam Systems
D Casing drains may be required on a waste heat boiler gas passage side to __________. prevent an accumulation of boiler water entering gas passages as a result of a pinhole tube leak as a means to sample stack gases for testing release excess pressure drain off condensation Steam Systems
D Constant capacity, pressure atomizing, fuel burners designed to meet a wide variation in steaming loads on an auxiliary boiler, are __________. automatically supplied with warmer air on demand automatically supplied with more fuel on demand equipped with standard variable capacity atomizers cycled on and off in response to steam demand Steam Systems
C The primary function of a flame safeguard system, as used on an automatically fired auxiliary boiler, is to prevent __________. accidental dry firing and overpressure uncontrolled fires in the furnace explosions in the boiler furnace overheating of the pressure parts Steam Systems
A A photoelectric cell installed in an automatically fired auxiliary boiler burner management system __________. opens the burner circuit upon sensing a flame failure detects a flame failure by monitoring radiant heat from glowing refractory requires mechanical linkage to secure the burner fuel supply must be bypassed at low firing rates Steam Systems
A During unsafe firing conditions in a large automatic auxiliary boiler, various control actuators are interlocked with the burner circuit to prevent start-up, in addition to safety shutdown. These controls are referred to as __________. limit controls flame safeguard controls combustion controls programming controls Steam Systems
D The pressuretrol which is installed on an auxiliary boiler senses steam pressure changes and __________. controls the flow of feed water to the boiler monitors the boiler high water level secures the fires when a fusible plug burns out automatically regulates the quantity of oil and air flow to the burner Steam Systems
C Which of the following statements describes how the fuel oil enters the whirling chambers of the sprayer plates used in a auxiliary boiler return flow fuel oil system? Through the outer barrel tube. Through the sprayer plate drilled passages. Through tangential slots in the sprayer plate. Through baffles in the orifice plate. Steam Systems
C The solenoid valves in the fuel oil supply line to an automatically fired auxiliary boiler, are automatically closed by __________. a decrease in feed temperature high furnace air pressure high steam pressure low steam pressure Steam Systems
B A variable capacity, pressure atomizing, fuel oil burner functions to __________. maintain a constant fuel temperature provide a wide range of combustion provide a constant fuel return pressure maintain smokeless fuel oil atomization Steam Systems
A When the steam pressure drops below a set value on an automatically fired auxiliary boiler, fitted with rotary cup atomizers, the combustion control system will __________. increase the fuel oil control valve opening increase the rotary cup speed decrease the back pressure regulating valve opening decrease the supply steam control valve opening Steam Systems
B Control of the fuel oil metering valve in an automatically fired auxiliary boiler is accomplished by a __________. pressure magnifying device in the steam coil outlet steam pressure sensing device with linkage to the damper air vanes metering device in the air supply line signal from the feed water electrode Steam Systems
B In the water level electrode assembly, shown in the illustration, the feed pump should restart when the level of the water reaches the position indicated by arrow __________. Illustration MO-0047 B C E D Steam Systems
A Which of the following types of feedwater regulators is commonly used with a water-tube, natural circulation, auxiliary boiler? Thermo mechanical Bimetallic element Ring thermostat Modulating pressuretrol Steam Systems
D Heavy soot accumulations in an auxiliary boiler could be caused by __________. water in the fuel oil excessive cycling high fuel oil pressure improper burner maintenance Steam Systems
A Burner ignition failure in an automatically fired auxiliary boiler would be caused by __________. a burned out solenoid in the oil supply valve high temperature excess air incorrectly setting the hot well dump valve an incorrectly positioned burner snubber relay Steam Systems
C In the event of a flame failure in an auxiliary water-tube boiler, you must __________. relight the boiler immediately to prevent loss of steam pressure relight the fire off the brickwork as long as the bricks are cherry red purge the furnace of any combustible gases before attempting to relight the fire speed up the feed pump to prevent dry firing when the burner flame is reestablished Steam Systems
D A burner producing black smoke in an automatic auxiliary boiler, would be caused by a/an __________. incorrect electrode setting defective solenoid valve grounded high tension lead incorrect primary air setting Steam Systems
B A feed pump for an auxiliary boiler might lose suction if the __________. boiler water level is low feed water is too hot boiler steam demand is low feed water is too cold Steam Systems
D A safety valve on an auxiliary boiler simmers constantly and cannot be stopped by several quick blow-offs using the hand relieving gear. The problem may be __________. loose dirt on the seat exposed valve springs a clogged drain line a damaged seat Steam Systems
B Which of the following devices will increase the power output of a diesel engine without increasing its frictional load? Gear-driven centrifugal blower Turbine-driven centrifugal blower Roots-type rotary blower Positive displacement blower Turbo Charging and Scavenging Systems
C A loop or cross scavenged engine utilizes the motion of its pistons and a turbocharger to provide scavenging air. Which of the listed mechanical designs prevents the air under the pistons from being pumped back through the scavenge ports during the piston power stroke? Positive pressure from the blower Masked intake ports Length of the piston skirt Lower liner seals Turbo Charging and Scavenging Systems
D Clearance volume scavenging in a turbocharged, four-stroke/cycle diesel engine is accomplished __________. with only the exhaust valve open without cooling the cylinders or pistons at a pressure below atmospheric during the valve overlap period Turbo Charging and Scavenging Systems
D In a turbocharger, inlet air velocity is increased in the __________. compressor outlet volute stationary diffuser passages inlet nozzle ring rotating impeller vanes Turbo Charging and Scavenging Systems
B Which of the following statements is correct regarding a turbocharged four-stroke cycle diesel- generator? At full load the intake manifold pressure and exhaust manifold pressure are equal. At full load the intake manifold pressure is greater than the exhaust manifold pressure. At zero load the intake manifold pressure is greater than the exhaust manifold pressure. At full load the intake manifold pressure is less than the exhaust manifold pressure. Turbo Charging and Scavenging Systems
A Large, two-stroke/cycle, main propulsion, diesel engine cylinders can be successfully pressure charged during normal operation, by using the __________. constant or pulse pressure system constant volume system exhaust load system exhaust gas temperature system Turbo Charging and Scavenging Systems
A In a two cycle diesel engine, a Roots type blower is usually __________. gear driven by the engine driven by separate motor actuated by the intake valves driven by an exhaust gas turbine Turbo Charging and Scavenging Systems
D The diesel engine shown in the illustration, is provided with an auxiliary blower to __________. Illustration MO-0003 maintain a positive pressure on the crankcase increase scavenge air pressure at full load maintain a vacuum on the crankcase provide scavenge air pressure at low load Turbo Charging and Scavenging Systems
C Maintaining the lowest possible scavenging air temperature at all times is not recommended due to the possibility of the __________. compression pressure being greatly reduced air charge density becoming too high formation of excessive quantities of condensate piston crown surfaces becoming too cold Turbo Charging and Scavenging Systems
D Which of the following precautions should be taken when cleaning the air filter on a diesel engine equipped with a turbocharger? Reduce engine speed to idle before removing the filter. Soak the dirty filter in kerosene only. Blow out the air inlet with compressed air. With the engine stopped, cover the air inlet after removing the filter. Turbo Charging and Scavenging Systems
D Following the failure of one turbocharger on a large, crosshead, main propulsion diesel engine, fitted with multiple turbochargers, which of the following actions should be taken prior to further operation of the engine? Blank off the exhaust gas inlet to the damaged turbocharger. Secure cooling and lubrication to the damaged turbocharger. Lock the rotor of the damaged turbocharger. All of the above. Turbo Charging and Scavenging Systems
C When checking for the presence of sulfite in the feed water of an auxiliary boiler, you are in essence checking __________. the hardness of the makeup feed water to ensure the compound additions are adequate for control of pH to ensure the compound additions are adequate for controlling dissolved oxygen to ensure the automatic or manual blow down rate and frequency is adequate for control of total dissolved solids Waste Heat / Auxiliary Boiler
D Before any work is done on a burner in an automatically fired auxiliary boiler, you should always __________. block all control valves allow the boiler to cool completely lock all safety interlock switches closed close all manually operated fuel valves Waste Heat / Auxiliary Boiler
C Before any work is to be carried out on a burner in an automatically fired auxiliary boiler, you should always __________. block all control system relays closed allow the boiler to cool completely close all manually operated fuel valves lock all safety interlock switches closed Waste Heat / Auxiliary Boiler