Chief Engineer OSV Practice Test (OSE01)

Chief of the engine room on offshore supply vessels: motor plants, general subjects, safety, electrical. Coast Guard exam code OSE01.

277 real questions from the Coast Guard National Maritime Center's public sample exams, free. Each module needs 70% to pass.

Passing score: Coast Guard pass marks module by module, and the retest rules

What's free: daily rounds, the Brig, the drills and the Pass Meter, for every license. Your first module test is free too. After that, the full Exam Room is $19, once. No subscription.

What's on the test

Picture questions link to the drawing in the Coast Guard's free sample PDF. A few that need reference tables are left out.

10 sample questions

1. Diesel engine closed, re-circulating cooling water systems are particularly prone to cavitation corrosion/erosion. Which of the listed cooling system/engine components has surfaces in contact with the coolant that are most susceptible to this type of corrosion and erosion?

   • A.Engine exhaust cooling water jackets
   • B.Wet-type cylinder liners
   • C.Cylinder cooling water jackets
   • D.Cylinder head cooling water passages
   Show answer

   B. Wet-type cylinder liners

   Q610, Assistant Engineer Limited: Motor Plants

2. In general, the thermal bulb for a thermal expansion valve used in a reciprocating air conditioning system is usually charged with what substance?

   • A.mercuric sulfate
   • B.bees wax
   • C.the same refrigerant as the system
   • D.distilled water
   Show answer

   C. the same refrigerant as the system

   Q801, Junior Engineer, Part II

3. You have abandoned ship and are in charge of a liferaft. How much water per day should you permit each occupant to drink after the first 24 hours?

   • A.1 quart
   • B.1 gallon
   • C.1 pint
   • D.1 can
   Show answer

   C. 1 pint

   Q445, Lifeboat Operator

4. Prior to using an analog multimeter set up as an ohmmeter, the leads are purposely shorted together. Which of the following actions should be taken if, when adjusting to "zero" ohms, the indicating needle cannot be returned to "zero" on the scale?

   • A.The batteries should be replaced.
   • B.The test reading should be added to each final reading.
   • C.The test reading should be subtracted from each final reading.
   • D.The lead clips should be replaced.
   Show answer

   A. The batteries should be replaced.

   Q604, Chief Engineer Limited: Electrical, Electronics & Control

5. What statement concerning fuel cetane rating and the ignition delay period is true as it applies to offshore anchor handling vessel main propulsion diesel engines?

   • A.The ignition delay period is the lag in time between when fuel injection actually begins and when combustion actually begins, and the higher the cetane rating of the fuel the longer the ignition delay period.
   • B.The ignition delay period is the lag in time between when fuel injection actually begins and when combustion actually begins, and the higher the cetane rating of the fuel the shorter the ignition delay period.
   • C.The ignition delay period is the lag in time between when fuel injection is initiated and when fuel injection actually begins, and the higher the cetane rating of the fuel the longer the ignition delay period.
   • D.The ignition delay period is the lag in time between when fuel injection is initiated and when fuel injection actually begins, and the higher the cetane rating of the fuel the shorter the ignition delay period.
   Show answer

   B. The ignition delay period is the lag in time between when fuel injection actually begins and when combustion actually begins, and the higher the cetane rating of the fuel the shorter the ignition delay period.

   Q650, Assistant Engineer OSV: Motor Plants

6. What is the color-coding for a storage container of R-134a refrigerant?

   • A.green
   • B.grey
   • C.purple
   • D.light blue
   Show answer

   D. light blue

   Q804, Oiler, Part I

7. Petroleum vapors are dangerous __________.

   • A.only if the oxygen concentration is below 16 percent
   • B.only if the vapor is between the upper and lower explosive limit
   • C.only if the source of the vapor is above its flash point
   • D.at all times due to their toxicity
   Show answer

   D. at all times due to their toxicity

   Q801, Junior Engineer, Part II

8. In what situation would an electrical phase sequence indicator be useful?

   • A.preparing to parallel alternators
   • B.connecting shore power lines to the ship
   • C.connecting lighting branch circuits
   • D.troubleshooting DC motors
   Show answer

   B. connecting shore power lines to the ship

   Q604, Chief Engineer Limited: Electrical, Electronics & Control

9. When starting a deck winch drive engine in preparation for cargo handling operations, what parameter must be checked FIRST upon start-up to avoid immediate engine damage?

   • A.Cylinder jacket water pump discharge pressure
   • B.Fuel oil supply header pressure
   • C.Deck winch gear oil pump discharge pressure
   • D.Engine lubricating oil supply header pressure
   Show answer

   D. Engine lubricating oil supply header pressure

   Q650, Assistant Engineer OSV: Motor Plants

10. When new piping sections have been fabricated for installation in a hydraulic system, prior to installation the piping should be __________.

    • A.descaled by using a pickling solution
    • B.hydrostatically tested to 100% of maximum working pressure
    • C.cleaned using a water-based detergent
    • D.all of the above
    Show answer

    A. descaled by using a pickling solution

    Q601, Chief Engineer Limited: General Subjects

What the study guide does

• Short daily rounds of 10 questions, with a streak.
• Practice tests built like the real one, scored with the real pass marks (first one free, then $19 once for the full Exam Room).
• The Brig: questions you miss come back until you get them right twice.
• Pass Meter: your chance of passing every module if you sat it today, worked out from your own answers.