MODU – Assistant Engineer, Revision & Practice Exams

Which of the following is required to be included in the fireman's (emergency) outfit?

1. Chemical protection face shield
2. Approved work vest
3. Self-contained breathing apparatus ✓
4. 5 cell approved flashlight

Which of the listed characteristics applies to a semi-portable CO2 system?

1. Each cylinder must weigh less than 50 pounds.
2. It has distribution piping installed permanently.
3. The cylinders are mounted horizontally.
4. It has a portable hose and nozzle. ✓

The longer an oil fire is permitted to burn, the __________.

1. easier it is to control
2. easier it is to extinguish
3. harder it is to extinguish ✓
4. less chance there is of reignition

Barrel face, taper face, grooved, and chrome plated are all types of diesel engine __________.

1. pistons
2. piston rings ✓
3. piston skirts
4. cylinder liners

The diesel generator set drive engines on your vessel are protected with heavy-duty oil bath air cleaners. The oil within these air cleaners should be periodically replaced in accordance with manufacturer recommendations. What statement best describes when it would be appropriate to deviate from the recommended frequency?

1. Replace the oil less frequently when the engine is exposed to dusty conditions (such as arc welding in the engine room), and replace the oil more frequently when the oil is unusually dirty or when it thickens.
2. Replace the oil more frequently when the engine is exposed to dusty conditions (such as arc welding in the engine room), and replace the oil more frequently when the oil is unusually dirty or when it thickens. ✓
3. Replace the oil more frequently when the engine is exposed to dusty conditions (such as arc welding in the engine room), and replace the oil less frequently when the oil is unusually dirty or when it thickens.
4. Replace the oil less frequently when the engine is exposed to dusty conditions (such as arc welding in the engine room), and replace the oil less frequently when the oil is unusually dirty or when it thickens.

The pilot valves in an air pilot starting system for a two-stroke cycle, direct reversing, main propulsion diesel engine are operated by either a ported distributor disc or a/an __________.

1. regulator valve
2. quick opening main air valve
3. pilot air start check valve
4. individual cam for each pilot valve ✓

The TBN value of diesel engine lube oil refers to its ability to __________.

1. resist changes in viscosity with changes in temperature
2. resist emulsification
3. neutralize acids ✓
4. resist oxidation at high temperatures

What may cause a diesel engine cylinder head to crack?

1. Overheated intake valves
2. A leaking oil control ring
3. Heat transfer from exhaust valves
4. Scale on cooling passages ✓

The process of scavenging a two-stroke cycle diesel engine serves to __________.

1. Improve fuel flow volume
2. Cool the exhaust valves ✓
3. Reduce the intake air charge density
4. Increase the temperature of exhaust gases

Which of the turbocharging methods listed directs the exhaust gases to the turbine at fairly uniform velocity and pressure?

1. Constant pressure ✓
2. Pulse pressure
3. Constant velocity
4. Axial flow

You are preparing to change the oil of the speed control governor on one of the main propulsion diesel engines on your vessel. What statement is true concerning the draining and flushing procedures?

1. The governor oil should be drained while the oil is hot and the governor should be flushed with the heaviest grade of the same type of oil.
2. The governor oil should be drained while the oil is cold and the governor should be flushed with the lightest grade of the same type of oil.
3. The governor oil should be drained while the oil is hot and the governor should be flushed with the lightest grade of the same type of oil. ✓
4. The governor oil should be drained while the oil is cold and the governor should be flushed with the heaviest grade of the same type of oil.

Which of the following actions takes place in the control circuit of an automatically fired auxiliary boiler when the desired steam pressure is obtained?

1. A temperature sensing device opens the circuit breaker in the burner motor.
2. The stack relay actuates the low limit control which breaks the ignition circuit.
3. The high limit control secures power to the entire oil firing system. ✓
4. The stack relay secures power to the high voltage side of the ignition transformer.

On which of the following auxiliary boiler types would soot blowers most likely be fitted?

1. Water-tube natural-circulation steam boiler ✓
2. Water-tube forced-circulation steam boiler
3. Electric steam boiler
4. Fire-tube steam boiler

After measuring the length to which a section of shoring should be cut, you should cut the shoring __________.

1. approximately 1/2 inch longer than the measured length to allow for trimming
2. approximately 1/2 inch shorter than the measured length to allow for the use of wedges ✓
3. approximately 1/2 inch shorter per foot of the measured length to allow for wet expansion
4. to the same length as the measured length

In accordance with 46 CFR, life jackets should be stowed in __________.

1. The forepeaks
2. The pumproom
3. Readily accessible spaces ✓
4. Locked watertight containers

The external flotation bladder on an immersion suit should be inflated __________.

1. before you enter the water
2. after you enter the water ✓
3. after one hour in the water
4. after you notice that your suit is losing buoyancy

Which of the gases listed is the poisonous gas most likely to be found in a closed compartment involved in a fire?

1. Nitrogen
2. Hydrogen
3. Carbon dioxide
4. Carbon monoxide ✓

A burning mattress is considered as which of the following classes of fire?

1. Class "A" ✓
2. Class "B"
3. Class "C"
4. Class "D"

Which of the listed components of a hydraulic system would enable the pump to be temporarily shut down, and yet still provide an instantaneous source of hydraulic force?

1. Sump actuator
2. Pressure compensator valve
3. Modulator
4. Accumulator ✓

In order to distribute the side pressures over a wide area of the cylinder walls and liners, which of the listed types of pistons are used in modern low-pressure air compressors?

1. Differential
2. Valve-in-head
3. Trunk ✓
4. Barrel

Both the direction of flow and fluid flow rate of a variable displacement radial piston pump are determined by the relative positions of the __________.

1. floating ring and pump shaft
2. floating ring and cylinder body ✓
3. pump shaft and horizontal ports
4. pump shaft and central valve

Of the following, what shipboard system is MOST likely to use the synchronous transmission system featuring a transmitter and receiver?

1. Shaft revolution indicator system
2. Turbocharger RPM indicator system
3. Centrifuge RPM indicator system
4. Rudder angle indicator system ✓

With regard to the number of passes through the tubes of shell-and-tube heat exchangers, what statement is true?

1. In two-pass and four-pass heat exchangers, the inlet and outlet tube-side fluid connections are at the same end. ✓
2. In single-pass and two-pass heat exchangers, the inlet and outlet tube-side fluid connections are at the same end.
3. In single-pass and two-pass heat exchangers, the inlet and outlet tube-side fluid connections are at opposite ends.
4. In two-pass and four-pass heat exchangers, the inlet and outlet tube-side fluid connections are at opposite ends.

In a refrigeration system, the bulb for the thermal expansion valve is always located where?

1. in the middle of the evaporator coils
2. at the evaporator coil inlet
3. at the evaporator coil outlet ✓
4. at the beginning of the bottom row of the evaporator coils

The amount of HCFC-123 in a storage cylinder is measured by what means?

1. saturation temperature
2. weight ✓
3. saturation pressure
4. volume

Contact with any energized electrical system conductor is potentially hazardous and precautions should be taken to prevent exposure. With all other factors considered equal (such as voltage, conducting path through the body and the duration of contact), contact with an energized electrical system conductor of which system type would produce the most damaging effect?

1. DC systems
2. 60 Hz AC systems ✓
3. 10 kHz AC systems
4. All the above systems would be equally as damaging

What is meant by the term emergency bilge suction?

1. The means by which the machinery space bilge is pumped out by a pump not normally used as a bilge pump and drawing a suction on the bilge through either bilge manifolds or automatic bilge suction valves.
2. The means by which the machinery space bilge is pumped out by a pump not normally used as a bilge pump and drawing a suction directly on the bilge independent of any bilge manifolds or automatic bilge suction valves. ✓
3. The means by which the machinery space bilge is pumped out by a pump normally used as a bilge pump and drawing a suction directly on the bilge independent of any bilge manifolds or automatic bilge suction valves.
4. The means by which the machinery space bilge is pumped out by a pump normally used as a bilge pump and drawing a suction on the bilge through either bilge manifolds or automatic bilge suction valves.