10 exam-style questions with answers and explanations, straight from our 1,030-question bank. Tap an answer to check yourself. When you're ready, take the scored version in the free practice test.
After a fuel-injection pump is refitted on a mechanically injected propulsion diesel, one cylinder has a higher exhaust temperature and a lower peak firing pressure than before. Its pressure trace shows normal compression but a later combustion-pressure rise. The injector passes its opening-pressure and spray tests, and the other cylinders remain normal at the same engine load. Which fault best accounts for the combined findings?
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Correct answer: C - Retarded injection timing on the affected cylinder
Question 2
Two identical 600 kW diesel generators run in parallel with equal governor droop settings and manual load adjustment. No. 1 carries 250 kW and No. 2 carries 550 kW; each supplies 150 kvar. Bus frequency is 60 Hz and the ship's load is steady. To equalize real-power loading while maintaining bus frequency, the engineer should:
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Correct answer: A - Raise No. 1's governor setting and lower No. 2's.
Question 3
A large steam consumer opens suddenly. Boiler pressure falls, steam flow increases, and the drum-level indication initially rises even though feedwater flow has not increased. The level remains within operating limits. Which feedwater-control strategy avoids treating this transient indication as proof of excess water inventory?
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Correct answer: D - Match feedwater to steam flow, with drum-level correction.
Question 4
The provision-room refrigeration plant runs steadily but has lost cooling capacity. Evaporator airflow is normal. At the evaporator outlet, the zeotropic refrigerant's pressure corresponds to a dew point of -10°C and a bubble point of -16°C; vapor temperature at that location is +2°C. Liquid is strongly subcooled upstream of the filter-drier, which now has a substantial pressure drop and local cooling across it. Select the superheat value and diagnosis that fit these observations.
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Correct answer: B - 12 K; restricted liquid-line filter-drier.
Question 5
While the vessel is maneuvering, differential pressure across the propulsion lubricating-oil duplex filter reaches its specified changeover point. Oil temperature is normal, bearing-header pressure is steady within its operating range, and no bearing alarms are present. The clean chamber is filled, vented, and ready; the approved arrangement permits uninterrupted changeover. What is the appropriate response?
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Correct answer: B - Change to the clean chamber while monitoring bearing-header pressure.
Question 6
A loading check starts with a vessel displacement of 6,000 tonnes, KM of 7.90 m, and KG of 7.00 m. The crew proposes moving 120 tonnes of equipment vertically upward by 6.0 m, without adding or removing weight. KM remains unchanged, and the total free-surface correction remains 0.18 m. The approved loading condition requires corrected initial GM of at least 0.65 m. Which result belongs in the completed check?
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Correct answer: D - GM is 0.60 m; the proposed condition fails the requirement.
Question 7
The gas-turbine start log records successful light-off followed by rotor speed leveling off below the required self-sustaining speed. Fuel is cut off when the permitted acceleration time expires. Gas-path temperature stayed below the start limit, and there were no large compressor-pressure oscillations. How should this unsuccessful start be classified?
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Correct answer: A - Hung start: combustion occurred, but acceleration was not completed.
Question 8
Following alterations to the central cooling system, the first assistant engineer reviews the shipyard acceptance records. The duty pump supplies the required load, but the standby pump has not operated since the pipework was changed. The system is intended to recover automatically from duty-pump failure. Which additional evidence most directly demonstrates that this redundancy has been restored?
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Correct answer: C - A controlled automatic changeover test confirming standby flow and recovery of header pressure.
Question 9
A single-rod, double-acting hydraulic cylinder must retract against 36 kN of axial resistance. Its full piston area is 50 cm² and the rod cross-sectional area is 20 cm². The maximum permitted supply pressure is 100 bar. Neglect friction and return-line pressure. At that pressure, what retraction force is available, and is it sufficient?
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Correct answer: A - 30 kN; insufficient for the required retraction.
Question 10
An oceangoing cargo ship in U.S. navigable waters is discharging machinery-space bilge water through approved, operating separating and monitoring equipment. The verified undiluted effluent reading is 8 ppm, but an oil sheen is observed and traced to this discharge. No oil cargo residues are involved. Which order should the first assistant engineer give immediately?
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Correct answer: C - Stop overboard discharge and retain the mixture for compliant disposal.
What's on the USCG-1AE exam
The National 1st Assistant Engineer Steam/Motor/GT (USCG-1AE) (USCG-1AE) exam is organized into 1 knowledge domains. These free practice questions are drawn from across them so you can see where you're strong and where to study:
Marine Engineering Knowledge and Professional Competencies
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