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100+ Free Assistant Engineer-MODU Practice Questions

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2026 Statistics

Key Facts: Assistant Engineer-MODU Exam

MODE02

NMC Exam Code

USCG NMC Engine Officer Exams

Q715–Q717

Exam Modules

USCG NMC MODE02

~50

Typical questions per module (confirm NMC ESS)

Common candidate lists / study guides

70%

Passing score per module

USCG NMC engineering exam standard

3 years / 18 months listed

Primary MODU service path

46 CFR 11.544(a)(1)(i)

11.201(h)

Required firefighting course

46 CFR 11.544(a)(2)

15 ppm

Machinery-space bilge oil discharge limit

MARPOL Annex I

~$240–$255

Typical original officer fees

46 CFR 10.219

Assistant Engineer-MODU (NMC code MODE02) is the USCG national engineer officer exam for mobile offshore drilling units. Modules are Q715 Motor Plants, Q716 Engineering Safety & Environmental Protection, and Q717 General Subjects, each typically about 50 questions at 70% per common candidate lists (confirm current NMC ESS). Service paths are in 46 CFR 11.544 (MODU employment, machinist trade, or ABET degree routes) plus firefighting under 11.201(h); a non-self-propelled limitation is possible. Typical original officer fees are about $240–$255 under 46 CFR 10.219. Content is machinery-space engineering — not OIM or Barge Supervisor deck modules.

Sample Assistant Engineer-MODU Practice Questions

Try these sample questions to test your Assistant Engineer-MODU exam readiness. Each question includes a detailed explanation. Start the interactive quiz above for the full 100+ question experience with AI tutoring.

1In a four-stroke-cycle diesel engine, how many crankshaft revolutions are required to complete one full cycle in each cylinder?
A.One revolution (360°)
B.One-half revolution (180°)
C.Two revolutions (720°)
D.Three revolutions (1080°)
Explanation: A four-stroke diesel completes intake, compression, power, and exhaust over two crankshaft revolutions (720°), with one power stroke every other revolution.
2What is the primary purpose of fuel injection timing on a marine diesel engine?
A.To control jacket cooling-water temperature
B.To set the crank angle at which combustion begins so peak pressure occurs shortly after top dead center
C.To regulate scavenge-air volume only
D.To set lube-oil gallery pressure
Explanation: Injection timing fixes when fuel enters and burns; correct timing places peak cylinder pressure just after TDC for useful work without excessive mechanical stress.
3The chief function of scavenging in a two-stroke diesel is to:
A.Inject fuel at the correct crank angle
B.Remove burned gases from the cylinder and fill it with fresh air
C.Cool the injector tip between firings
D.Lubricate the wrist pin
Explanation: Scavenging uses pressurized fresh air to push exhaust out and charge the cylinder because a two-stroke has no separate exhaust stroke.
4A marine diesel governor primarily:
A.Limits maximum cylinder firing pressure by design only
B.Automatically adjusts fuel rack position to maintain set speed under changing load
C.Controls jacket-water thermostat setting
D.Times exhaust-valve opening
Explanation: The governor senses engine speed and repositions the fuel control to hold the selected speed as load changes.
5Black smoke from a diesel exhaust under normal load most commonly indicates:
A.Excess lube oil burning in the combustion space
B.Water leaking into a cylinder
C.Incomplete combustion from excess fuel or insufficient air
D.Normal idle operation
Explanation: Black smoke is unburned carbon from incomplete combustion, typically from overfueling, fouled air path, or poor injector spray.
6What is the main purpose of a turbocharger on a marine diesel?
A.To raise fuel pressure to the injectors
B.To use exhaust energy to compress intake air and increase power output
C.To cool exhaust before the silencer
D.To dampen crankshaft torsional vibration
Explanation: A turbocharger turbine driven by exhaust spins a compressor that packs more air into the cylinders so more fuel can be burned safely.
7If starting air is applied but the engine will not turn and air pressure is normal, the most likely cause is that the:
A.Expansion tank is slightly low
B.Turning (jacking) gear is still engaged
C.Day-tank fuel viscosity is slightly high
D.Crankcase oil is slightly above the high mark
Explanation: An engaged turning gear mechanically locks the engine; interlocks or the locked gear prevent rotation on starting air.
8Jacket cooling water that is too cold during continuous operation can cause:
A.Higher thermal efficiency with no drawbacks
B.Increased thermal stress and possible condensation of combustion products on liner walls
C.Immediate turbocharger overspeed only
D.Automatic increase of injection timing
Explanation: Overcooling increases thermal stress and can promote cold corrosion/condensation of acids on cylinder walls; operators keep jacket temperature in the prescribed band.
9The primary purpose of the diesel engine lube-oil system is to:
A.Cool only the turbocharger exhaust casing
B.Lubricate and cool bearings and other friction surfaces while carrying away heat and contaminants
C.Provide starting air to the cylinders
D.Meter fuel to the injectors
Explanation: Lube oil separates moving surfaces with an oil film, removes heat, and transports wear particles and combustion by-products to filters.
10A sudden rise in lube-oil temperature with falling pressure on a main diesel most nearly indicates:
A.Normal warm-up after a cold start only
B.Possible bearing distress, thinning oil film, or restricted oil flow requiring immediate investigation
C.That jacket-water temperature is too low
D.That the fuel day tank is empty
Explanation: Rising oil temperature with falling pressure is a classic hot-bearing or lubrication-casualty symptom; reduce load/stop per procedure and investigate before catastrophic failure.

About the Assistant Engineer-MODU Exam

The USCG Assistant Engineer-MODU endorsement (NMC exam code MODE02) authorizes service as assistant engineer on mobile offshore drilling units under 46 CFR 11.544 and 11.540. Candidates qualify by one of several paths: three years of MODU employment including 18 months in listed capacities with nine months on self-propelled or propulsion-assisted units; a machinist-trade path with MODU assignment; or an ABET (or NMC-accepted) marine/mechanical/electrical engineering technology degree plus six months in a listed capacity on self-propelled or propulsion-assisted units — plus firefighting training under 46 CFR 11.201(h). The examination is three multiple-choice modules (Q715–Q717) covering motor plants, engineering safety and environmental protection, and general engineering subjects. Applicants who lack self-propelled service may receive a non-self-propelled limitation under 46 CFR 11.544(b).

Assessment

MODE02 = Q715 Motor Plants + Q716 Engineering Safety & Environmental Protection + Q717 General Subjects. Each module independently graded at 70%. REC rules commonly allow up to 3.5 hours per module, minimum two modules per day when multiple remain, modules completed on consecutive days within the same business week. Engine candidates receive 46 CFR Parts 1–199 and 33 CFR Parts 1–199 as room references.

Time Limit

Up to 3.5 hours per module

Passing Score

70% on each module

Exam Fee

$100 evaluation + $45 issuance plus the applicable 46 CFR 10.219 examination fee ($110 upper level / $95 lower level for an original); about $240–$255 in total. Confirm the fee row with the NMC for MODU engineer applications. (U.S. Coast Guard National Maritime Center (NMC) / Regional Exam Centers)

Assistant Engineer-MODU Exam Content Outline

33%

Motor Plants (Q715)

Diesel cycle fundamentals, two- and four-stroke marine engines, fuel systems and injection, turbocharging and scavenging, governors, jacket and lube oil systems, starting air, auxiliary diesels/generators, and motor-plant casualty control on MODUs

33%

Engineering Safety & Environmental Protection (Q716)

Fire classes and fixed/portable systems, SCBA and enclosed-space entry, H2S and flammable-gas awareness offshore, flooding and dewatering, lockout/tagout, MARPOL 15 ppm bilge discharge and Oil Record Book, OPA 90, and hazardous materials/SDS

34%

General Subjects (Q717)

Centrifugal and positive-displacement pumps, cavitation and NPSH, hydraulics, heat exchangers, refrigeration, valves and piping, bilge and oily-water separators, AC generators and motor controllers, batteries, and engineer watchkeeping on MODU machinery spaces

How to Pass the Assistant Engineer-MODU Exam

What You Need to Know

  • Passing score: 70% on each module
  • Assessment: MODE02 = Q715 Motor Plants + Q716 Engineering Safety & Environmental Protection + Q717 General Subjects. Each module independently graded at 70%. REC rules commonly allow up to 3.5 hours per module, minimum two modules per day when multiple remain, modules completed on consecutive days within the same business week. Engine candidates receive 46 CFR Parts 1–199 and 33 CFR Parts 1–199 as room references.
  • Time limit: Up to 3.5 hours per module
  • Exam fee: $100 evaluation + $45 issuance plus the applicable 46 CFR 10.219 examination fee ($110 upper level / $95 lower level for an original); about $240–$255 in total. Confirm the fee row with the NMC for MODU engineer applications.

Keys to Passing

  • Work through all 100 available questions
  • Review every answer and explanation
  • Track weak areas and revisit them
  • Use our AI tutor for tough concepts

Assistant Engineer-MODU Study Tips from Top Performers

1Treat each of Q715, Q716, and Q717 as a separate 70% pass — drill motor plants, safety/environmental, and general subjects as independent modules.
2For Q715, master diesel injection timing, turbocharging, jacket-water and lube-oil alarms, starting-air safety, and crankcase oil-mist / hot-bearing response.
3For Q716, memorize fire classes, CO2 total-flooding evacuation rules, enclosed-space entry, H2S IDLH and PPE concepts, and the MARPOL 15 ppm bilge limit with Oil Record Book awareness.
4For Q717, practice pump NPSH/cavitation, hydraulic relief-valve purpose, generator paralleling basics, motor overload protection, and OWS operation.
5Include calculation MCQs: Ohm's law and three-phase power, pump rate × time = volume, fuel consumption, and simple heat-exchanger temperature differences.
6Do not study OIM/Barge Supervisor deck modules for this endorsement — stay in the engineer machinery domain.
7Simulate timed sets matching common ~50-question module length before your REC appointment.
8Keep firefighting certificates and service letters aligned with 46 CFR 11.544 and 11.201(h) before applying through NMC ASAP.

Frequently Asked Questions

What does the Assistant Engineer-MODU endorsement authorize?

Under 46 CFR 11.540 and 11.544, the Assistant Engineer-MODU endorsement authorizes service as assistant engineer on mobile offshore drilling units within the scope of the endorsement (including any non-self-propelled limitation if issued).

How is the MODE02 exam structured?

MODE02 is delivered as three multiple-choice modules: Q715 Motor Plants, Q716 Engineering Safety & Environmental Protection, and Q717 General Subjects. Each module is graded independently and requires a minimum of 70% to pass.

How many questions are on each MODE02 module?

Common candidate lists and study guides cite about 50 multiple-choice questions per module (Q715, Q716, Q717) at 70%. Exact module size is controlled by the current NMC Exam Structure Sheet and sample exams — confirm on the NMC MODE02 page before your REC appointment.

What experience is required under 46 CFR 11.544?

One path is three years of MODU employment including 18 months as Mechanic, Motorman, Subsea Engineer, Electrician, Barge Engineer, Toolpusher, Unit Superintendent, Crane Operator, or equivalent, with nine months on self-propelled or propulsion-assisted units. Alternates include a machinist-trade path with required MODU time, or an ABET engineering technology degree plus six months in a listed capacity on self-propelled or propulsion-assisted units. Firefighting training under 46 CFR 11.201(h) is also required.

Can the endorsement be limited to non-self-propelled units?

Yes. Under 46 CFR 11.544(b), if you pass the exam and have the total required service but lack the required self-propelled or propulsion-assisted service, the Coast Guard may issue an endorsement limited to non-self-propelled units and later remove the limitation when the missing service (and any additional required examination) is completed.

Is this the same as OIM, Barge Supervisor, or Ballast Control Operator?

No. Assistant Engineer-MODU (MODE02) is an engineer officer path focused on machinery spaces. Offshore Installation Manager, Barge Supervisor, and Ballast Control Operator are separate MODU officer paths with different exam codes and service rules. Do not mix those deck-oriented banks with MODE02.

What are the fees?

Under 46 CFR 10.219, a typical original officer package is $100 evaluation, an examination fee of $95 (lower level) or $110 (upper level), and $45 issuance (about $240–$255). Confirm the fee row the NMC applies to your MODU engineer transaction and pay via Pay.gov.

Is this free practice bank an official Coast Guard exam?

No. It is a free English multiple-choice study aid covering MODE02 topic areas for 2026. Official modules are administered by the Coast Guard at Regional Exam Centers using current NMC banks.