Chief Engineer MODU Practice Test (MODE01)

Chief engineer on mobile offshore drilling units (drill rigs): motor plants, safety, general subjects. Coast Guard exam code MODE01.

208 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. Which of the following problems could develop due to the accumulation of oil vapors in the crankcase of a diesel engine?

   • A.Reduced lubrication
   • B.Combustion knock
   • C.Crankcase explosion
   • D.Poor fuel economy
   Show answer

   C. Crankcase explosion

   Q808, Pump Technician

2. 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

3. 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

4. During main engine performance testing it is noticed that the firing pressure of one cylinder is higher than the average, but cylinder compression pressure is normal. Which of the following would most likely be the cause?

   • A.Early fuel injection
   • B.Worn piston rings
   • C.Late fuel injection
   • D.High engine load
   Show answer

   A. Early fuel injection

   Q602, Chief Engineer Limited: Motor Plants

5. The principal personnel hazard unique to Halon fire extinguishers is __________.

   • A.skin irritation
   • B.eye irritation produced immediately after discharge from cylinder
   • C.inhaling toxic vapors produced when exposed directly to a flame for extended periods
   • D.displacement of oxygen
   Show answer

   C. inhaling toxic vapors produced when exposed directly to a flame for extended periods

   Q802, Electrician

6. A refrigeration compressor used in a multi-box refrigeration system, is designed with six of its eight cylinders able to be controlled for variable load conditions. If all of the reefer boxes are currently feeding, what percentage of the total number of compressor cylinders will be loaded after start-up?

   • A.100%
   • B.50%
   • C.25%
   • D.0%
   Show answer

   A. 100%

   Q801, Junior Engineer, Part II

7. In a four-stroke cycle diesel engine, badly worn intake valve guides can cause excessive _________.

   • A.exhaust temperatures
   • B.exhaust pressure
   • C.lube oil consumption
   • D.cooling water temperatures
   Show answer

   C. lube oil consumption

   Q602, Chief Engineer Limited: Motor Plants

8. You notice smoke coming from an open laundry room doorway, which smells like electrical insulation. After activating the fire alarm, which of the following would be the lowest action priority?

   • A.Secure power to the washers and dryers.
   • B.Break out the nearest fire hose.
   • C.Close the door to the room.
   • D.Locate the nearest CO2 or dry chemical extinguisher.
   Show answer

   B. Break out the nearest fire hose.

   Q802, Electrician

9. What is the purpose of running a refrigeration compressor in short intermittent spurts or throttling the suction isolation valve when starting the system after a prolonged shutdown?

   • A.let the refrigerated compartment cool gradually
   • B.allow refrigerant vapor cycling time
   • C.determine actual compressor oil level
   • D.prevent liquid slugging or overloading the compressor
   Show answer

   D. prevent liquid slugging or overloading the compressor

   Q803, Refrigerating Engineer

10. One remedy for a high firing pressure, in addition to a high exhaust temperature in one cylinder of a diesel engine, is to __________.

    • A.adjust the fuel rack
    • B.reduce fuel booster pump pressure
    • C.increase scavenge air pressure
    • D.retard fuel injector timing
    Show answer

    A. adjust the fuel rack

    Q602, Chief Engineer Limited: Motor Plants

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.