DDE – 1000/4000 HP, Revision & Practice Exams

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 is the clutch shown in the attached illustration engaged? Illustration GT-0018

1. Clutch is engaged manually prior to start up.
2. Clutch engages automatically when input shaft flange is rotating faster than the output assembly. ✓
3. Clutch engages automatically once the output assembly begins rotating.
4. Pneumatic pressure from the compressor engages the clutch.

During an auto-start sequence on the marine gas turbine control console shown in the illustration, what would be the correct order of events required to occur after the start sequence begins? Illustration GT-0016

1. NGG reaches ignition RPM, gas temperature greater than 400 degrees F, NGG reaches idle RPM. ✓
2. Power turbine reaches ignition RPM, gas temperature greater than 400 degrees F, power turbine reaches idle RPM.
3. NGG reaches idle RPM, power turbine reaches ignition RPM, gas temperature greater than 400 degrees F.
4. Power turbine reaches ignition RPM, gas temperature greater than 400 degrees F, NGG reaches idle RPM.

Accelerometers are generally used on gas turbine engines to sense which of the following?

1. High frequency vibration. ✓
2. Rate of rotor speed changes.
3. Gas generator speed with respect to power turbine speed.
4. PLARA rate limited feedback to the FSEE.

The hand brake of a lifeboat winch is __________.

1. manually disengaged when hoisting a boat
2. applied by dropping the counterweighted lever ✓
3. controlled by the centrifugal brake mechanism
4. automatically engaged if lowering speed is excessive

A hand portable CO2 fire extinguisher is effective on burning oil only __________.

1. To prevent rekindling
2. If applied promptly ✓
3. If applied in connection with foam
4. If attempts to extinguish the fire with low velocity fog have failed

The vapors given off by heated fuel oil are flammable, explosive, and __________.

1. non-toxic
2. heavier than air ✓
3. lighter than air
4. odorless

If the chemical material is a mixture, what must the Safety Data Sheet (SDS) identify?

1. Other similar mixtures of liquids, solids or gases.
2. Paints or coatings that are safe to use with it.
3. The name of each hazardous ingredient. ✓
4. None of the above.

Which of the precautions listed should be observed when taking on diesel fuel?

1. Prohibit smoking in the area. ✓
2. Secure all lighting to the main deck.
3. Display a black triangle during daylight hours.
4. Provide a portable fan to blow away fumes.

In the absence of external forces, adding weight to one side of a floating vessel, will cause the vessel to __________.

1. trim to the side opposite TCG until all moments are equal
2. list until the center of buoyancy is aligned vertically with the center of gravity ✓
3. heel until the angle of loll is reached
4. decrease draft at the center of flotation

Which of the illustrated motors has an open, drip-proof (ODP) motor enclosure? Illustration EL-0001

1. A
2. B
3. C ✓
4. D

Treatment of boiler feedwater for the control of hardness is necessary to prevent __________.

1. foaming
2. excessive feedwater alkalinity
3. carryover
4. waterside scale deposits ✓

The correct radial clearances between the rotor and the casing in a propulsion turbine are maintained by the turbine __________.

1. diaphragms
2. interstage packing
3. thrust bearing
4. journal bearings ✓

Turbine casing flanges are sometimes provided with a system of joint grooving to __________.

1. form a labyrinth seal between the casing halves
2. ensure perfect alignment of casing halves
3. inject sealing compound between the casing halves ✓
4. increase contact pressure between the casing halves' flanges

Thermal energy is the only form of energy that can be added to or removed from a substance. How is thermal energy that is added to a substance stored?

1. In the form of potential kinetic energy.
2. In the form of heat.
3. In the form of mechanical energy.
4. In the form of internal energy. ✓

Compressor surge is caused by which of the following factors?

1. Maximum fuel pressure
2. Increased demand for secondary air
3. Low ambient air temperature
4. Interrupted air flow ✓

Which of the following refrigerants is normally classified as a low-pressure refrigerant based on a relatively high boiling point?

1. HCFC-22
2. HCFC-123
3. HFC-23 ✓
4. HFC-134A

A flat block placed under the end of a shore for the purpose of distributing pressure is referred to as a __________.

1. shore foot
2. butt piece
3. strongback
4. shole ✓

A tank or compartment is "gas free" when there is an absence of dangerous concentrations of __________.

1. residues from cargo oil
2. all flammable liquids
3. flammable or toxic gases ✓
4. any combustible liquid

Ships requiring extremely rapid maneuvering response using propeller shaft speed and direction as the sole means of controlling propeller thrust are most likely to use what type of drive system?

1. Diesel-electric drive ✓
2. Direct or geared diesel drive
3. Steam turbine geared drive
4. Gas turbine geared drive

When checking the cylinder jacket water cooling expansion tank level on a main propulsion diesel engine on your towing vessel while underway on a coast-wise voyage, what should be the expansion tank level?

1. The level should be in the upper part of the sight glass when the engine is at operating temperature. ✓
2. The level should be out of sight high in the sight glass when the engine is at operating temperature.
3. The level should be in the lower part of the sight glass when the engine is at operating temperature.
4. The actual level is unimportant as long as it is visible in the sight glass when the engine is at operating temperature.

The diesel engines on your towing vessel are all protected with dry-type air filters. The air filters should be inspected and replaced in accordance with manufacturer instructions. What is the generally accepted criteria that would dictate when filter replacement becomes necessary?

1. The air filter element should be replaced when the pressure rise across the element increases above the specified maximum.
2. The air filter element should be replaced when the pressure rise across the element decreases below the specified minimum.
3. The air filter element should be replaced when the pressure drop across the element decreases below the specified minimum.
4. The air filter element should be replaced when the pressure drop across the element increases above the specified maximum. ✓

You are replacing an automotive type cooling water thermostat on one of the diesel generator sets on your ship docking tug. The markings on the original thermostat indicate that it was set to begin opening at 180oF. Which of the following thermostats marked for Celsius would be a replacement that comes closest to the value at which opening begins as compared to the original thermostat?

1. 70oC
2. 80oC ✓
3. 90oC
4. 100oC

The river push boat to which you are assigned is fitted with generator engines as partly shown in the illustration. What statement is true concerning the cylinders? Illustration MO-0163

1. The cylinder walls are integral (non-replaceable) to the cylinder block.
2. The cylinder liners are of the wet type and are replaceable inserts. ✓
3. The cylinder liners are of the jacketed type and are replaceable inserts.
4. The cylinder liners are of the dry type and are replaceable inserts.

The river push boat to which you are assigned has diesel generators fitted with intake and exhaust systems as shown in the illustration. What does the component labeled "3" represent? Illustration MO-0176

1. Exhaust manifold
2. Charge air manifold
3. Wet muffler
4. Charge air cooler ✓

Suppose each of the main propulsion engines on your harbor assist tug is equipped with a variable speed governor equipped with a solenoid actuated shutdown device. After a high temperature alarm, after continuing to rise, what is the most likely engine high temperature condition that would initiate a safety trip shutdown?

1. High charge air temperature
2. High fuel temperature
3. High exhaust temperature
4. High jacket water temperature ✓

The steam generating plant on your articulated tug-barge unit is of the forced-circulation type. Which figure of the illustration represents a steam generator or boiler of this type? Illustration MO-0197

1. 1
2. 2
3. 3 ✓
4. 4

Suppose the generator set drive engines on your ship docking tug are fitted with hydraulic isochronous governors such as shown in the illustration. How is the speed set point conveyed from the generator control panel on the main switchboard conveyed to the governor fitted on the diesel engine? Illustration MO-0160

1. Hydraulically via tubing connections
2. Mechanically via cable connections
3. Pneumatically via tubing connections
4. Electrically via wire connections ✓

As the percentage of CO2 in the stack gas decreases, you can assume that __________.

1. excess air is increasing ✓
2. the fuel to air ratio is increasing
3. fuel is being burned with increasing economy
4. you are approaching secondary combustion

Which procedure should be followed to dry out the fireside of a boiler after water washing?

1. Use a wire reinforced steam hose to put superheated steam in the furnace for 6 hours.
2. Place trays of silica gel in the furnace.
3. Open the furnace registers and run the forced draft fans for 3 hours.
4. Alternately fire one burner for 15-minute intervals during a 5-hour period. ✓

Design characteristics of a velocity-compounded impulse turbine include the utilization of __________.

1. two or more simple impulse stages
2. one or more nozzles with one row of rotating blades
3. a low velocity steam jet from a nozzle
4. a single pressure stage with two or more velocity stages ✓

A turbine assembly in which steam flows in series through a high-pressure turbine and then on to a low- pressure turbine, with both turbines driving a common reduction gear through separate shafts, is classified as _________.

1. cross compound ✓
2. tandem compound
3. tandem, double flow
4. dual series

Where do fuel oil vapors tend to accumulate in an engine room?

1. In the upper engine room spaces, especially in the fidley
2. Oil vapors tend to distribute throughout the engine room evenly
3. At the point in the engine room where the vapors were initially formed
4. In the lower engine room spaces, especially in the bilges ✓

What is the purpose of the air/oil separator shown in the illustration of the gas turbine lube oil system? Illustration GT-0024

1. Minimize oil consumption by separating oily vapors being vented to the atmosphere ✓
2. Reduce oil foaming
3. Maintain oil pressure in the sumps
4. All of the above

During cargo operations, a deck fire has occurred due to a leaking cargo line. You should FIRST __________.

1. blanket the cargo spill with foam
2. prevent the spread of fire with a foam dam
3. apply CO2 on the burning fuel at its source
4. stop the transfer of cargo ✓

If the cause of severe list or trim of a vessel is due to off-center ballast, counter-flooding into empty tanks will __________.

1. increase the righting moment
2. increase the righting arm
3. increase list or trim
4. decrease list or trim ✓

What can be the cause of excessive heat or burning contacts in an operating motor controller?

1. burned out operating coil
2. high ambient temperature
3. low motor starting torque
4. dirty or pitted contacts ✓

What statement concerning fuel cetane rating and the ignition delay period is true as it applies to towboat main propulsion diesel engines?

1. 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.
2. 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.
3. 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.
4. 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. ✓

The various auxiliary diesel engines fitted on your sea-going tug may employ a variety of different starting systems. What type of starting system is shown in the illustration? Illustration MO-0049

1. Electric power operated system
2. Gas engine power operated system
3. Pneumatic power operated system
4. Hydraulic power operated system ✓

Related to the diesel fuels used in auxiliary and main propulsion diesel engines used on the ship-docking tug to which you are assigned, the unit of measure expressed as centistokes (cSt) is a measure of what fuel property?

1. Heating value
2. Density
3. Cetane rating
4. Viscosity ✓

Assuming the use of ultra-low sulfur content diesel fuel, what combination of conditions associated with harbor tug engine room operations would require the most frequent draining of exhaust systems of condensation?

1. Winter operations with lengthy ship escort transit times.
2. Summer operations with lengthy ship escort transit times.
3. Summer operations with prolonged idling on station.
4. Winter operations with prolonged idling on station. ✓

You are assigned to a tractor tug with a drive system as shown in figure "A" of the illustration. What type of propulsion drive system is illustrated? Illustration MO-0140

1. Azimuthing propeller drive (z-drive)
2. Controllable pitch propeller drive
3. Conventional fixed-propeller drive
4. Cycloidal propeller drive ✓

By which of the listed methods may heat be transferred from one body to another?

1. Radiation
2. Convection
3. Conduction
4. All of the above. ✓

When monitoring a steam propulsion plant lubricating oil pressures, what pressure is the most critical to check regularly while underway?

1. The pressure immediately upstream of the variable orifice.
2. The pressure at the most remote bearing. ✓
3. Lube oil service pump discharge pressure.
4. The pressure immediately downstream of the variable orifice.

Which of the coupling types listed is shown in the illustration? Illustration SE-0001

1. Solid
2. Pin
3. Gear ✓
4. Claw

The purpose of the boiler drum air cock is to __________.

1. admit air when the boiler is being emptied
2. permit escape of air when steam is forming in the drum after lighting off
3. permit escape of air when the boiler is being filled
4. all of the above ✓

When cleaning the inside surfaces of the boiler tubes of a water-tube boiler with a powered rotary brush, the brush should be kept in motion to __________.

1. avoid internal tube damage ✓
2. reduce wear to brush bristles
3. reduce tube pitting
4. prevent it from seizing

Which of the following is the definition of absolute temperature?

1. Temperature measured with reference to the theoretical temperature at which all molecular motion stops. ✓
2. Temperature measured with reference to 0 degrees Fahrenheit.
3. Temperature measured with reference to 0 degrees Celsius.
4. Temperature measured with reference to 273 degrees Rankine.

A pressure stage of an axial-type compressor consists of which of the following?

1. Set of rotor blades and a set of stator blades ✓
2. Set of rotor blades
3. Compressor rotor and a set of inlet guide vanes
4. Set of stator blades

Which of the following components removes the oil from the transfer gearbox?

1. Lube and scavenge pump ✓
2. Lube oil storage and conditioning assembly
3. Air/Oil separator
4. Duplex filter assembly

As shown in the illustration of a gas turbine fuel oil system, when the engine fuel oil valves are de-energized, the remaining fuel left in the system is recirculated back to which of the following? Illustration GT-0021

1. Fuel purge manifold
2. High-pressure relief valve
3. Day tank
4. Fuel pump inlet ✓

The explosive range of methane is 5% to 15% by volume in air. This means a vapor/air mixture of __________.

1. 3 percent methane by volume is too rich to burn
2. 5 percent methane by volume will give a reading of 100 percent LEL on a combustible gas indicator ✓
3. 10 percent methane by volume is too rich to burn
4. 20 percent methane by volume is too lean to burn

Which of the following statements is true regarding mechanical seals?

1. They may be used in lieu of conventional packing glands for any service other than salt water.
2. They are not suitable for use on fuel oil transfer pumps.
3. They are normally lubricated and cooled by the fluid being pumped. ✓
4. Once placed into service, leakage between the dynamic seal surfaces may be reduced by monthly adjustment of the spring compression.

What is the pressure and condition of the refrigerant entering the receiver of a refrigeration system?

1. subcooled high-pressure liquid ✓
2. subcooled low-pressure liquid
3. superheated low-pressure vapor
4. superheated high-pressure vapor

What must be done, at a minimum, before a system can legally be opened up for repairs while adhering to the prohibition against the venting of halogenated fluorocarbon refrigerants to the atmosphere?

1. reclamation of the refrigerant
2. recycling of the refrigerant
3. destruction of the refrigerant
4. recovery of the refrigerant ✓

A split-phase induction squirrel-cage motor will not start and come up to speed, even though the rated voltage and frequency are applied. Assuming that the motor hums without rotating, which of the following troubles would MOST likely be suspected?

1. a shorted thermal protector
2. a shorted centrifugal switch
3. a shorted rotor bar
4. an open run or start winding ✓

Three 12-volt, lead-acid, batteries connected in series will develop how many volts?

1. 12 volts
2. 24 volts
3. 36 volts ✓
4. 48 volts

Which of the valves listed is NOT considered to be a hydraulic system directional control valve?

1. Three-position valve
2. Two-position valve
3. Detented-position valve
4. Counterbalance valve ✓

The rudder torque capacity of the four-ram steering gear illustrated, is rated at 44,210,000 inch-pounds with one power unit in operation. If the four-ram system was able to be operated as a two-ram system with both power units online, what would be the available torque? Illustration GS-0067

1. 11,052,500 inch-pounds
2. 22,105,000 inch-pounds ✓
3. 44,210,000 inch-pounds
4. 88,420,000 inch-pounds