GASCO - Advanced Training for Liquefied Gas Tanker Cargo Operations Exit Exam Questions - Set 14

Question 1

Which cargo tank level measuring system is commonly used as a primary system?

Accepted Answer

A: Radar tank gaug

Answer

B: Nitrogen bubbler gaug

Answer

C: float gauges

Answer

D: steel tape measurements

Question 2

Liquefied gas carriers are normally loaded or unloaded through__________situated amidships.

Accepted Answer

B: Manifolds

Answer

A: Cargo pumps

Answer

C: stripping pumps

Answer

D: ESD valves

Question 3

What test is carried out to ensure that all stripping / spray pumps are operational? Hint: this test is is often done after leaving the loading port as it is allows time for installation of an auxiliary cargo pump should it be necessary.

Accepted Answer

B: Meggar test

Answer

A: Snip test

Answer

C: cold test

Answer

D: load test

Question 4

What is the approximate temperature desired on board on LNG tanker, for the output from the forcing vaporizer?

Accepted Answer

B: -40C

Answer

A: -70C

Answer

C: -60C

Answer

D: -50C

Question 5

What is the purpose of having a cofferdam heating system?

Accepted Answer

B: To ensure that the cofferdam and liquid domes spaces are at all time kept at +5C when at loaded voyag

Answer

A: To generate sufficient boil- off to sustain dual fuel firing for the boiler in engine room.

Answer

C: To increase cargo temperature before arrival at discharge terminal

Answer

D: To ensure efficiency of vaporizer operation during the cooling down operation

Question 6

Which of the following options is an exception in a typical LNG boil off gas reliquefication plant?

Accepted Answer

B: forced vaporization

Answer

A: cargo cycl

Answer

C: nitrogen or cooling vaporization

Answer

D: auxiliary cycl

Question 7

After extinguishing a paint locker fire using the fixed CO2 system, the next immediate action is for the space to be

Accepted Answer

B: left closed with ventilation off until all boundaries are cool

Answer

A: opened and burned material removed

Answer

C: checked for the proper oxygen level

Answer

D: opened and doused with water to prevent reflash

Question 8

Smoke detectors, the correct answer is,

Accepted Answer

C: photoelectric type smoke detectors are in the detecting panel of CO2 flooding system

Answer

A: ionization type smoke detectors are in the detecting panel of CO2 flooding system

Answer

B: photoelectric type smoke detectors are in the machinery spaces

Question 9

which of the following conditions can contribute to accidents ?

Accepted Answer

C: unsafe conditions

Answer

A: good housekeeping

Answer

B: inspections

Answer

D: intelligent work habits

Question 10

If the concentration of the fuel is less than 5% LNG vapors cannot burn because of inadequate___________

Accepted Answer

A: LNG fuel

Answer

B: oxygen

Answer

C: nitrogen

Question 11

BLEVE stands for "boiling liquid expanding vapor ___________"

Accepted Answer

B: explosion

Answer

A: expansion

Answer

C: expression

Question 12

what marking must be clearly visible on a crane?

Accepted Answer

B: safe workin load

Answer

A: manufacturer's logo

Answer

C: make of the cran

Question 13

which chemical is used to treat water in order to ensure its safety for drinking?

Accepted Answer

B: chlorin

Answer

A: nitrogen

Answer

C: carbon

Answer

D: oxygen

Question 14

In a polarographic oxygen analyzers using chemical cells find an incorrect statement

Accepted Answer

A: batteries should neverbe changed in agas dangerous zon

Answer

B: such instruments have dual scales each having a separate function

Answer

C: such instruments are affected by magnetic fields around the test zon

Answer

D: scale 1- oxygen deficiency in air - 0-25% oxygen by volum

Answer

E: scale 2- oxygen in nitrogen - 0-1% oxygen by volum

Question 15

what is the typical measuring range for an oxygen analyzer?

Accepted Answer

B: 0- 25% volume oxygen in air

Answer

A: 10ppm volume oxygen in air

Answer

C: 0-5% volume oxygen in air

Answer

D: 0-100% volume oxygen in air

Question 16

What is typically the first action taken when there is a serious primary membrane leak?

Accepted Answer

A: Equalize the primary insulation space and vapor dome pressurees of the affected cargo tank

Answer

B: Stop filling the affected cargo tank's primary insulations with nitrogen

Answer

C: open up the affected cargo tank's primary insulations with inspection

Answer

D: Warming up the affected cargo tank immediately

Question 17

On an LNG tanker, during discharging why is it necessary to maintain the trim of 3m by stern during final discharging before completion of bulk discharge?

Accepted Answer

C: to ensure maximum discharge of cargo prior to warming up of cargo tanks

Answer

A: To ensure proper draining of ballast water from ballast tank

Answer

B: to increase boil-off of cargo while discharging

Answer

D: to maximize boil-off of cargo with by increased exposed surface area

Question 18

Onboard an LNG carrier, during loading operations, why should be- ballasting be done concurrently with loading?

Accepted Answer

B: to keep the vessel within the required limit of draft, trim, stress and stabilty

Answer

A: to reduce vessel turnaround tim

Answer

C: to ensure that the gangway is safe for use at all times

Answer

D: deballasting can be done after 50% loading is complet

Question 19

What is the average recommended cooling down rate of cargo tanks?

Accepted Answer

B: 10-12 °C/ hour

Answer

A: 20-22 °C/ hour

Answer

C: 30-32 °C/ hour

Answer

D: 40-42 °C/ hour

Question 20

What is the objective of drying cargo tanks?

Accepted Answer

D: to reduce moisture content

Answer

A: to warm the cargo tanks prior to inerting

Answer

B: to remove methane residual

Answer

C: to prevent damagee of cargo equipment

Question 21

Onboard an LNG carrier, during loading operation which is the correct sequence of liquid flow during loading operation?

Accepted Answer

B: terminal- manifold crossover- main liquid line- tank filling val

Answer

A: terminal- spary line- main liquid line- tank filling val

Answer

C: terminal- manifold crossover - main vapor line- tank filling val

Answer

D: terminal-manifold crossover - main liquid line- spary lin

Question 22

Where is the cargo tanks warming up operation normally carried out?

Accepted Answer

C: in sheltered waters where the mixture can be exhausted without danger

Answer

A: in port when alongside as this is a routine, non-critical operation

Answer

B: it can be done anywhere but at sea as shore support is required

Answer

D: it is done after entry into the drydock

Question 23

Onboard an LNG carrier, why should CO2 which may freeze be removed prior to cool down?

Accepted Answer

B: at 60 °C CO2 freex=zes to form a powder which can block line components

Answer

A: oxygen in the CO2 can form an explosive mixture with LNG

Answer

C: to increase cargo carrying capacity

Answer

D: to prevent corrosive effect of CO2 / lng mixtur

Question 24

In membrane class LNG carriers, what is the expected changes in the primary insulation space during the cooldown?

Accepted Answer

B: pressuree drops due to fall in tank wall temperatur

Answer

A: pressuree rises due to increase in tank wall temperatur

Answer

C: pressuree is not affected by tank cooldown

Answer

D: pressuree rises then drops

Question 25

All pipelines associated with cargo have to be purged with ig for at least for 5 min, which of these does not require purging with IG?

Accepted Answer

B: insulation space lines

Answer

A: fuel gas heaters pipelines

Answer

C: hd & ld gas compressors discharge lin

Answer

D: vapor and liquid manifolds

Question 26

On an Lng tanker during the initial stage of cooling down operation, prior discharging why is it necessary to open the main loading valves of the forward and the aft cargo tanks?

Accepted Answer

D: to purge the vapor which remains at both ends of the liquid header

Answer

A: to ensure liquid flow into the forward and aft cargo tanks

Answer

B: to increase the pressuree in the cargo tanks before discharging

Answer

C: to clean anhy impurities in the pipelines before discharging

Question 27

For the gt no. 96 containment system, what is the recommended inlet temperature of warm LNG vapor into the cargo tanks?

Accepted Answer

B: +80 °C

Answer

A: -80 °C

Answer

C: +120 °C

Answer

D: +20 °C

Question 28

ONboard LNG tanker, why is it necessary to maintain gas burning during loaded passage?

Accepted Answer

A: to maintain/ control cargo tank pressuree and prevent venting

Answer

B: to minimize heavy fuel oil consumption

Answer

C: to maintain constant pressuree in the insuation spaces

Answer

D: to maximize quantity of boil- off use in boiler

Question 29

What is cargo capacity to which an LNG carrier's cargo tanks can be safety loaded?

Accepted Answer

B: 98.5% of total cargo tank capacity of the vessel

Answer

A: 95% of total cargo tank capacity of the vessel

Answer

C: total capacity available in cargo tank

Answer

D: spare available for cargo after reduction of vapour spac

Question 30

During cool down when" free flow " of gas, from cargo tanks to shore, is not effective and cargo tanks pressure increases, what is the best solution?

Accepted Answer

B: start hd compressor and return gas to shor

Answer

A: start ld compressor and return gas to shor

Answer

C: increase the set point of common raiser vent setting

Answer

D: shut the vapor manifold valv

Advanced Training for Liquefied Gas Tanker Cargo Operations (GASCO) (Set 14)

Which cargo tank level measuring system is commonly used as a primary system?

Questions in GASCO Set 14

Question Discussion & Notes

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