USCG Assistant Engineer Uninspected Fishing Industry Vessels (UFIV02)

On a marine diesel engine, what is the primary purpose of fuel injection timing?

• ATo control jacket-water temperature
• BTo regulate turbocharger boost pressure
• CTo set the crank angle at which fuel begins to burn so peak pressure occurs shortly after…
• DTo set day-tank fuel viscosity

A diesel engine will not rotate when starting air is admitted, although air pressure is normal. The most likely cause is that the:

• ACooling expansion tank is slightly low
• BTurning (jacking) gear is still engaged
• CFuel oil is too cold for the day-tank heater setpoint
• DCrankcase oil level is slightly above the high mark

In a four-stroke-cycle diesel engine, how many crankshaft revolutions complete one full cycle in each cylinder?

• AOne revolution (360°)
• BOne-half revolution (180°)
• CThree revolutions (1080°)
• DTwo revolutions (720°)

What is the chief function of scavenging in a two-stroke marine diesel?

• ATo inject fuel at the correct crank angle
• BTo remove burned gases from the cylinder and replace them with fresh air
• CTo lubricate the wrist pin
• DTo cool the injector tip between firings

Many fishing vessels cool the main engine with a keel cooler instead of a raw-water heat exchanger because a keel cooler:

• ACirculates seawater directly through the engine jackets
• BKeeps engine coolant in a closed loop and rejects heat through external piping in contact…
• CRemoves the need for any coolant circulating pump
• DEliminates the need for corrosion inhibitor in the coolant

On a four-stroke marine diesel, the camshaft is driven at:

• ATwice crankshaft speed
• BHalf crankshaft speed
• CThe same speed as the crankshaft
• DA speed varied by the governor with load

Blue or blue-grey exhaust smoke from a marine diesel typically indicates:

• AOverfueling with clean injectors
• BBurning of lubricating oil in the combustion space
• CNormal complete combustion
• DCoolant entering the combustion chamber

On a fishing-vessel main diesel, the fuel oil viscosity controller is primarily intended to:

• ARaise fuel heating value
• BKeep fuel at the viscosity required for proper atomization at the injectors
• CRemove water from the day tank
• DIncrease cetane number

What is the primary purpose of a charge-air (after) cooler on a turbocharged marine diesel?

• ATo heat scavenging air for better vaporization
• BTo cool compressed intake air so denser air enters the cylinders
• CTo cool jacket water leaving the engine
• DTo condense exhaust for muffling

If turbocharger compressor fouling reduces airflow on a workboat diesel under load, the engineer should expect:

• ALower exhaust temperature and white smoke only
• BHigher exhaust temperature and black smoke from incomplete combustion
• CImmediate crankcase explosion
• DAutomatic increase in governor setpoint only

Starting air receivers for marine diesels are typically fitted with relief valves primarily to:

• ADry the starting air
• BProtect the receiver from overpressure
• CMeter air to each cylinder
• DHeat the air for better starting

Why must water be drained regularly from starting-air receivers on a fishing vessel?

• ATo increase starting-air temperature
• BTo prevent water carryover that can corrode lines and damage air-start components
• CTo raise compressor capacity
• DTo improve fuel atomization

Oil mist in a large diesel crankcase is dangerous primarily because it can:

• AImprove bearing lubrication
• BForm an explosive mixture that can ignite and cause a crankcase explosion
• CCool the pistons
• DNeutralize sulfur in the fuel

If oil-mist detection alarms on a main engine at sea, the safest first actions typically include:

• AOpen all crankcase doors immediately to ventilate
• BSlow or stop the engine per procedure and keep crankcase doors closed
• CIncrease load to burn off the mist
• DBypass the mist detector and continue full speed

Cylinder lubrication on a large two-stroke marine diesel is primarily intended to:

• ACool the turbocharger compressor
• BLubricate the liner/ring interface and help neutralize acidic combustion products
• CDrive the fuel pump cam
• DSeal the charge-air cooler

A sudden drop in main-engine lube-oil pressure at sea most urgently requires the engineer to:

• AIncrease fuel rack to restore speed
• BReduce load/stop the engine per emergency procedure before bearings are damaged
• COpen the crankcase doors to inspect
• DBypass the lube-oil cooler only

Jacket-water temperature on a marine diesel is primarily controlled by:

• AFuel injection timing advance only
• BA thermostatic or regulating valve that bypasses or admits cooler water
• CThe turbocharger wastegate alone
• DCrankcase breather vacuum

High jacket-water temperature on a fishing-vessel diesel under load could be caused by:

• AToo much charge-air cooling only
• BFouled heat exchanger, low coolant level, failed raw-water pump, or stuck temperature-con…
• CExcessively high lube-oil pressure alone
• DOver-draining the starting-air receiver

Mean effective pressure (MEP) in a diesel cylinder is best described as:

• AThe maximum peak firing pressure only
• BA theoretical constant pressure that would produce the same work as the actual cycle
• CThe turbocharger compressor discharge pressure
• DThe lube-oil gallery pressure

If an engineer calculates indicated horsepower from mean effective pressure, bore, stroke, RPM, and number of power strokes, an increase in MEP at constant RPM primarily indicates:

• ALower fuel consumption always
• BHigher indicated work (power) from the cylinders
• CLower cylinder peak pressure always
• DImmediate need to stop the engine

A diesel engine is rated 600 kW at 1800 rpm. Approximately what torque (N·m) does it develop at that rating? (Use T = 9550 × kW / rpm)

• AAbout 1,590 N·m
• BAbout 3,180 N·m
• CAbout 795 N·m
• DAbout 318 N·m

On many fishing vessels, the main diesel drives the propeller through a reduction gear primarily to:

• AIncrease propeller RPM above engine RPM
• BMatch engine best-efficiency speed to a lower, more efficient propeller speed
• CEliminate the need for a clutch
• DCool the lube oil

A controllable-pitch propeller (CPP) allows the engineer/operator to:

• AChange blade pitch to control thrust and load without changing engine speed as much as a…
• BEliminate the need for any hydraulic power
• CRemove the need for a reduction gear always
• DOperate without any governor

Detonation (knock) in a diesel is best described as:

• ANormal smooth combustion after ignition delay
• BAbnormal violent combustion with steep pressure rise after a long ignition delay or hot s…
• CComplete misfire with no pressure rise
• DTurbocharger surge only

Cetane number of diesel fuel primarily indicates:

• ASulfur content
• BIgnition quality (ease of auto-ignition and shorter ignition delay)
• CViscosity at 50°C only
• DWater content

Before starting a marine diesel that has been shut down cold, which check is most critical among the following?

• AThat the turbocharger is painted
• BThat lube-oil level/pressure capability, cooling water, fuel, and turning gear status are…
• CThat the oily water separator is in automatic only
• DThat the fish hold is full

A stuck-open fuel injector on one cylinder of a multi-cylinder diesel typically causes:

• AThat cylinder to stop receiving any fuel forever
• BLocal overfueling with knock, smoke, and elevated exhaust temperature on that cylinder
• CAutomatic reduction of all injectors equally
• DImmediate loss of all lube-oil pressure

The purpose of a diesel engine fuel injector nozzle is to:

• AMeter total engine horsepower at the governor only
• BAtomize fuel into the combustion chamber at high pressure for mixing with air
• CCool the charge-air cooler
• DDrive the camshaft

On residual-fuel plants, fuel oil is heated before injection primarily to:

• AIncrease sulfur content
• BLower viscosity for proper pumping and atomization
• CRemove all ash chemically
• DRaise cetane number automatically

A cracked cylinder head allowing jacket water into a diesel combustion chamber often shows as:

• ABlack smoke only with no other signs
• BWhite steam-like exhaust, loss of coolant, and possibly hydraulic lock on start
• CHigher lube-oil pressure only
• DAutomatic increase in cetane

What is the main purpose of an engine-driven or electric pre-lube pump on many medium-speed diesels?

• ATo cool exhaust valves only
• BTo establish oil pressure/film before starting and reduce dry-start wear
• CTo inject fuel at idle
• DTo scavenge the crankcase of mist

If a fishing vessel’s main engine overspeeds, the overspeed trip should:

• AIncrease fuel rack to maximum
• BShut off fuel (and/or air on some designs) to stop the engine
• COpen the sea chest fully
• DEngage the turning gear

Compared with a four-stroke diesel of similar size, a two-stroke marine diesel typically has:

• AA power stroke every two revolutions per cylinder
• BA power stroke every revolution per cylinder
• CNo need for scavenging air
• DNo need for lubrication

A pyrometer (EGT) reading much higher on one cylinder than the others under steady load most likely indicates:

• AThat cylinder is receiving less fuel than others always
• BA problem such as injector fault, valve issue, or local overfueling on that cylinder
• CNormal even balancing
• DThat the tachometer is failed only

Air-start valve leak-by into a diesel cylinder while running can be dangerous because:

• AIt cools the cylinder too much always
• BHot combustion gases can pass back into the starting-air manifold and create a fire/explo…
• CIt automatically trips the overspeed
• DIt increases cetane

When warming through a cold main diesel on a fishing vessel, the engineer should generally:

• AApply full load immediately to heat it faster
• BIdle/light load until temperatures and pressures stabilize in normal range
• CDisable all alarms until warm
• DDrain the entire lube-oil sump

A diesel develops 400 bhp. If mechanical efficiency is 80%, approximate indicated horsepower is:

• A320 ihp
• B400 ihp
• C500 ihp
• D480 ihp

Fouled fuel filters on a workboat diesel typically first show as:

• ARising fuel pressure at the injector always
• BLoss of power, hunting, or inability to take full load as fuel starvation develops
• CHigher lube-oil pressure
• DLower jacket-water temperature only

The flash point of diesel fuel is important on vessels because it indicates:

• AThe temperature at which fuel auto-ignites in a diesel cylinder
• BThe lowest temperature at which vapors can flash when an ignition source is applied—relev…
• CThe viscosity at 40°C
• DThe sulfur content in ppm

After a main-engine emergency stop due to low lube-oil pressure, the correct approach is to:

• ARestart immediately at full load to restore oil pressure by speed
• BInvestigate and correct the cause, restore oil level/pressure integrity, then restart onl…
• CBypass the LO pressure switch permanently
• DOpen all crankcase doors while still above idle

Immersion suits carried aboard a commercial fishing vessel must be:

• AStowed in the machinery space, where they stay warm and dry
• BCorrectly sized, stowed for rapid access, and inspected on a set schedule
• CLeft sealed in the maker's packaging until an actual emergency
• DShared, with one suit provided for every four crew

A 406 MHz EPIRB fitted to a fishing vessel is intended to:

• AProvide two-way voice communication with rescue authorities
• BTransmit a registered distress alert and position so search and rescue can be directed to…
• CSubstitute for carrying immersion suits
• DServe as the vessel's primary navigation position source

Before releasing a fixed CO2 total-flooding system into a machinery space, the engineer must ensure:

• AVentilation is maximized and people remain inside to operate valves
• BThe space is evacuated, ventilation is secured, and openings are closed as designed
• CAll fuel tanks are opened for venting
• DThe oily water separator is running

A quick-closing (remote) shutoff valve on a fuel service tank is fitted so that:

• AFuel viscosity to the engine can be regulated from the control station
• BFuel to the machinery space can be cut off from a position outside that space during a fi…
• CThe tank can be vented while it is being filled
• DFuel consumption can be metered for the engine-room log

Aqueous film-forming foam (AFFF) is especially effective on:

• AClass D metal fires only
• BClass B flammable liquid spill fires by blanketing and excluding air
• CEnergized high-voltage switchboards only
• DDeep-seated Class A coal bunker fires only

Enclosed machinery-space entry is hazardous primarily due to:

• AHigh oxygen enrichment always
• BOxygen deficiency, toxic gases, and flammable atmospheres
• CExcessive lighting only
• DLow ambient noise