OSV – Assistant Engineer, Revision & Practice Exams

A simple precaution to reduce the possibility of accidental fires in the paint locker, is to __________.

1. label the fixed firefighting system
2. store paint cans on metal shelves only
3. not allow oily rags to accumulate in the space ✓
4. place a portable fire extinguisher immediately outside the locker

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

How are fuses usually rated?

1. watts only
2. amps only
3. volts and amps only
4. volts, amps, and interrupting capacity ✓

Under unusual circumstances, it may be required to operate a ship's service generator above its rated kVA. What supplemental casualty control action will be required?

1. While maintaining the rated system frequency, lower the operating voltage to at least 5% below the rated system voltage.
2. Increase the cooling water flow, while maintaining air temperatures above the dew point to avoid any condensation. ✓
3. While maintaining the rated system voltage, lower the operating frequency to at least 5% below the rated system frequency.
4. Increase the cooling water flow, while maintaining air temperatures below the dew point for increased cooling effect.

Before any work on electrical or electronic equipment is performed, which of the following precautions should be carried out?

1. Station a man at the circuit supply switch.
2. Secure and tag the supply circuit breaker in the open position. ✓
3. De-energize the applicable switchboard bus.
4. Bypass the interlocks.

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

Who is responsible for lowering the survival craft?

1. Roustabout
2. First man aboard
3. Last man aboard
4. Helmsman ✓

Except in rare cases, it is impossible to extinguish a shipboard fire by __________.

1. Removing the fuel ✓
2. Removing the heat
3. Interrupting the chain reaction
4. Removing the oxygen

The class of fire on which a blanketing effect is essential to extinguish the fire is __________.

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

The most likely location for a liquid cargo fire to occur on a tanker would be __________.

1. In the amidships house
2. At the main deck manifold
3. At the vent header
4. In the pumproom ✓

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

What is the primary purpose of the lead-lag arrangement of the two potable water pumps supporting a typical potable water system?

1. Enabling the lead pump to pump against a shut-off head during periods of relatively low demand and the lag pump to recirculate when the demand is high.
2. Enabling both potable water pumps to cycle on and off together in response to system demand changes.
3. Enabling the lead pump to cycle on and off during periods of relatively low demand and the lag pump to assist the lead pump only when the demand is high. ✓
4. Enabling the lag pump to cycle on and off during periods of relatively low demand and the lead pump to assist the lag pump only when the demand is high.

What is an ammeter used to measure?

1. continuity
2. current ✓
3. resistance
4. voltage

When configuring a digital multimeter as an ohmmeter, what will MOST likely be displayed on the screen when the test leads are shorted together?

1. A reading of "OL" ohms will be displayed.
2. A reading of residual test lead and internal resistance will be displayed (typically .2 to .5 ohms).
3. A reading of 0 ohms will be displayed.
4. B or C could be correct depending upon the digital multimeter. ✓

How can the loss of residual magnetism in an alternator with a brushless excitation system be corrected?

1. using a storage battery or battery charger to "flash" the field ✓
2. running the generator at normal speed with the field rheostat fully counterclockwise
3. allowing the generator to run at 10% of normal speed for 5 minutes
4. running the rotor in the opposite direction for 5 minutes

The nominal voltage of one cell of a wet cell nickel-cadmium battery is approximately how many volts?

1. 1.2 volts ✓
2. 1.5 volts
3. 2.0 volts
4. 3.0 volts

How is the difference between the synchronous speed of a three-phase induction motor and its operating speed correctly expressed?

1. deviation
2. a decimal fraction of full load speed
3. slip ✓
4. a percent of full load speed

Which of the following statements about a three-phase wye connected alternator is correct?

1. The phase current is 1.73 times the line current.
2. The line voltage is 1.73 times the phase voltage. ✓
3. The phase voltage is 1.73 times the line voltage.
4. The line current is 1.73 times the phase current.

The arc resulting from the tripping of a circuit breaker is prevented from damaging the contacts. How is this done?

1. extinguishing the arc by means of an arc chute ✓
2. an inverse timed thermal trip for short circuit currents
3. designing the contacts to open slowly
4. instantaneous magnetic trip for overload currents

What is meant by the term independent bilge suction?

1. The means by which the machinery space bilge is pumped out by a pump not normally used as a bilge pump but using either bilge manifolds or automatic bilge suction valves.
2. The means by which a cargo-hold bilge is pumped out by a pump normally used as a bilge pump but independent of any bilge manifolds or automatic bilge suction valves.
3. The means by which a cargo-hold bilge is pumped out by a pump not normally used as a bilge pump but using either 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 but independent of any bilge manifolds or automatic bilge suction valves. ✓

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.

The determining factor for the strength of a flexible rubber hydraulic hose is the __________.

1. Teflon sleeve
2. braided layer ✓
3. synthetic rubber inner tube
4. external cover

Which of the following compressors would be used for a dead ship start-up of a ship's service diesel- generator on a motor ship?

1. Topping air compressor
2. Ship's service air compressor
3. Starting air compressor
4. Emergency air compressor ✓

Which of the following statements represents the proper criteria to decide when to drain a filter/moisture separator as used in a ship's service air system hose station?

1. The bowl should be drained whenever moisture droplets appear in the bowl.
2. The bowl should be drained before the moisture level reaches the lower baffle. ✓
3. The bowl should be drained after the bowl completely fills with moisture.
4. The bowl should be drained daily with no need to check the moisture level.

Which of the following liquid level sensors would be most suitable for measuring the liquid level in a pressure vessel, such as a water-tube boiler steam drum?

1. Capacitance probe
2. Differential pressure sensor ✓
3. Displacement float level sensor
4. Static pressure sensor

Which of the following roller bearing types would be limited to radial thrust load applications?

1. Single row tapered roller bearing
2. Single row spherical roller bearing
3. Single row cylindrical roller bearing ✓
4. Double row spherical roller bearing

Which of the following fuel systems is characterized by a complete absence of high-pressure fuel lines?

1. Rotary plunger type system
2. In-line multi-plunger type system
3. Unit injector type system ✓
4. Common rail type system

For diesel engines, such as those used for main propulsion and auxiliary power on offshore supply vessels, while running at speed, how is the ignition of fuel within the cylinder achieved?

1. Ignition is achieved by the heat of compression created by compressing intake/charge air within the cylinder into a relatively small volume. ✓
2. Ignition is achieved by a high voltage electric spark induced across the gap of a specially designed spark plug.
3. Ignition is achieved by the heat of compression created by compressing the air/fuel mixture within the cylinder into a relatively small volume.
4. Ignition is achieved by intense heat by passing electric current through the element of a specially designed glow plug.

In all diesel engines, including those used in offshore oil spill response vessels, at what point in the combustion cycle does ignition actually begin?

1. Near the completion of the expansion (power) event
2. At the beginning of the compression event
3. Near the completion of the compression event ✓
4. Near the completion of the scavenging event

Prior to starting a main propulsion diesel engine fitted on your multi-purpose offshore supply vessel, it has been determined that the transfer of make-up oil is required. At what checked level should you stop adding make-up oil?

1. When the oil level rises to the between the ADD and FULL marks on the side of the dipstick marked ENGINE STOPPED and OIL COLD.
2. When the oil level rises to a level well above the FULL mark on the side of the dipstick marked ENGINE STOPPED and OIL COLD.
3. When the oil level rises to the FULL mark on the side of the dipstick marked ENGINE STOPPED and OIL COLD. ✓
4. When the oil level rises to the ADD mark on the side of the dipstick marked ENGINE STOPPED and OIL COLD.

In preparation for getting a platform supply vessel underway, what is the primary factor to consider in whether or not pre-lubrication of the main propulsion engines shall be necessary?

1. The interval of time since the last engine overhaul
2. The viscosity of the lubricating oil
3. The length of time that the engine has been shutdown ✓
4. The ambient temperature in the engine room

When starting a main propulsion diesel engine fitted with attached pumps in preparation for getting underway on your offshore supply vessel, what parameter must be checked FIRST upon start-up to avoid immediate engine damage?

1. Sea water pump discharge pressure
2. Cylinder jacket water pump discharge pressure
3. Fuel oil supply header pressure
4. Lubricating oil supply header pressure ✓

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?

1. Fuel oil supply header pressure
2. Cylinder jacket water pump discharge pressure
3. Engine lubricating oil supply header pressure ✓
4. Deck winch gear oil pump discharge pressure

When checking the crankcase oil level on an off-line diesel generator set engine on your offshore oil spill response vessel, what should be the oil level as indicated on the dipstick?

1. The level should be below the ADD mark on the dipstick.
2. The level should be well above the FULL mark on the dipstick.
3. The level should be between the FULL and ADD marks on the dipstick. ✓
4. The actual level is unimportant as long as it is visible on the dipstick.

The main propulsion diesel engines used to power the offshore supply boat to which you are assigned are started with vane-type air-starting motors designed to operate at 250 psig. The in-line lubricator should provide 3 drops of oil per cranking minute, as long as the in-line lubricator oil viscosity is as specified. If the start air pressure is within the normal range and the oil viscosity is correct, but the oil injection rate is only 1 drop per minute, what should be done?

1. The oil in the in-line lubricator should be replaced with oil of lower viscosity than specified.
2. The starting air pressure supplied to the air-starting motors should be increased.
3. The in-line lubricator oil injection metering needle valve should be further opened. ✓
4. The in-line lubricator oil injection metering needle valve should be further closed.

Various diesel engines onboard your offshore supply vessel are started by means of either vane-type or air- turbine air-starting motors. At a minimum, in the absence of automatic drain valves, how often should moisture separators be drained of moisture while the vessel is underway?

1. Hourly
2. Daily ✓
3. Weekly
4. Monthly