GASCO exit exam questions and answers

All 351 questions from the Advanced Training for Liquefied Gas Tanker Cargo Operations (GASCO) exit exam bank, with the correct option marked and a one-line explanation for every one. Read it end to end, jump to a single set, or search it — then sit the same bank as a timed paper. The real DG Shipping exit exam is 30 marks with 15 to pass.

These are the bank's original groupings. Practising deals the whole bank out again every time you reshuffle, so a practice “Set 3” is a different 30 questions each time — the set numbers below are the source file's, and are only used here so the key stays navigable. Options are listed in their original order with fixed letters; when you practise, those move too.

Bank last rebuilt 8 Sep 2026.

Practise these GASCO questions GASCO mock exit exam, 30 marks GASCO exit exam sets and syllabus

351 of 351 shown

Nothing in this key matches that. Try a shorter word, or search the whole key.

Set 1 — 30 GASCO exit exam questions with answers

1. What is the primary component of Liquefied Natural Gas (LNG)?

A. Methane
B. Butane
C. Propane
D. Ethane

Answer: A — Methane

LNG consists predominantly of methane (typically over 85-95%) along with small percentages of ethane, propane, and butane.

2. At atmospheric pressure, what is the approximate boiling point of methane?

A. 42°C
B. 104°C
C. 0°C
D. 162°C

Answer: D — 162°C

Methane boils at approximately -161.5°C (-162°C) under standard atmospheric pressure.

3. Which code governs the construction and equipment of ships carrying liquefied gases in bulk?

A. IGC Code
B. IMSBC Code
C. IMDG Code
D. IBC Code

Answer: A — IGC Code

The International Code for the Construction and Equipment of Ships Carrying Liquefied Gases in Bulk (IGC Code) is mandatory under SOLAS Chapter VII.

4. What is the function of Boil-Off Gas (BOG) on an LNG carrier?

A. It is dumped directly into seawater
B. It must be vented continuously into the atmosphere
C. It is used to extinguish boiler fires
D. It is generated due to heat ingress and can be used as fuel or re-liquefied

Answer: D — It is generated due to heat ingress and can be used as fuel or re-liquefied

Boil-Off Gas (BOG) forms when cargo absorbs ambient heat. Modern gas carriers use BOG in dual-fuel propulsion engines or re-liquefy it back into the cargo tanks.

5. What gas is used to inert cargo tanks on gas carriers before introducing gas cargo?

A. Dry Nitrogen or Inert Gas with low O2
B. Oxygen
C. Compressed air
D. Carbon Dioxide only

Answer: A — Dry Nitrogen or Inert Gas with low O2

Nitrogen gas or dry inert gas (O2 < 5%) is used to displace oxygen from cargo tanks to prevent flammable atmosphere formation.

6. What is the Maximum Allowable Relief Valve Setting (MARVS) for a Type C independent tank on an LPG carrier?

A. Always negative pressure
B. Exactly 0.0 bar gauge
C. Less than 0.1 bar gauge
D. Greater than 0.7 bar gauge

Answer: D — Greater than 0.7 bar gauge

Type C independent tanks are pressure vessels designed for MARVS usually greater than 0.7 bar gauge (typically 5 to 18 bar gauge for fully pressurized tanks).

7. What risk is associated with rapid liquid cargo release onto steel deck structures?

A. Steel expansion and warping
B. Brittle fracture of hull steel due to extreme cold
C. Corrosion of hull plates
D. Immediate magnetic interference

Answer: B — Brittle fracture of hull steel due to extreme cold

Cryogenic liquids cause severe localized thermal shock and brittle fracture in normal ship steel. Water curtains and deck protection are used.

8. What type of pumps are most commonly used submerged inside LNG cargo tanks?

A. Steam reciprocating pumps
B. Screw positive displacement pumps
C. Submerged electric motor driven centrifugal pumps
D. Diaphragm hand pumps

Answer: C — Submerged electric motor driven centrifugal pumps

Submerged motor centrifugal pumps operate directly submerged in LNG liquid, as methane is electrical insulation in liquid phase with zero oxygen.

9. What instrument measures low concentration flammable gas by catalytic oxidation?

A. Explosimeter (Combustible Gas Indicator)
B. Hydrometer
C. Paramagnetic Oxygen Analyzer
D. Hygrometer

Answer: A — Explosimeter (Combustible Gas Indicator)

Explosimeters measure flammable vapor concentrations as a percentage of the Lower Explosive Limit (LEL).

10. What safety feature automatically trips cargo valves and pumps during an emergency ESD activation?

A. Quick Release Towing Hook
B. Auto-ignition Override
C. Manual Bilge Injection
D. Emergency Shutdown System (ESD)

Answer: D — Emergency Shutdown System (ESD)

The Emergency Shutdown (ESD) system stops cargo pumps, closes ESD valves, and isolates cargo transfer in emergency situations.

11. Under STCW Code Table A-V/1-2-2, what is the mandatory requirement regarding regulatory compliance and STCW code requirements during Advanced Liquefied Gas Tanker operations?

A. Applicable only during drydock operations
B. Strict compliance with approved safety procedures and flag state regulations
C. Verbal recommendation without documentation
D. Optional adherence based on vessel size

Answer: B — Strict compliance with approved safety procedures and flag state regulations

STCW Code Table A-V/1-2-2 mandates strict compliance with approved safety protocols for Advanced Liquefied Gas Tanker.

12. What specific safety precaution must be observed when managing regulatory compliance and STCW code requirements for Advanced Liquefied Gas Tanker on board?

A. Conducting a thorough risk assessment and briefing all involved personnel prior to starting work
B. Proceeding without informing the officer on watch
C. Delegating tasks exclusively to untrained crew members
D. Disabling automated safety alarms to save time

Answer: A — Conducting a thorough risk assessment and briefing all involved personnel prior to starting work

Risk assessments and pre-job briefings ensure all team members understand hazards during Advanced Liquefied Gas Tanker operations.

13. What is 'rollover' in an LNG cargo tank?

A. Over-rotation of the submerged pump impeller
B. Rapid mixing of two stratified liquid layers of different densities leading to sudden high gas evolution
C. Physical capsizing of the ship
D. Sloshing of cargo causing physical tank deformation

Answer: B — Rapid mixing of two stratified liquid layers of different densities leading to sudden high gas evolution

Rollover occurs when stratified LNG layers equalize densities rapidly, releasing large volumes of boil-off gas and causing sharp tank pressure rise.

14. What is the primary hazard of Ammonia ($NH_3$) when carried on gas tankers?

A. Non-flammable under all temperature conditions
B. High toxicity, corrosive nature, and stress corrosion cracking in steel
C. Zero toxicity and inert behavior
D. High radio-activity

Answer: B — High toxicity, corrosive nature, and stress corrosion cracking in steel

Ammonia is toxic, corrosive to copper alloys, and can cause stress corrosion cracking (SCC) in carbon-manganese steel tanks.

15. What insulation material is widely used in LNG membrane tanks?

A. Reinforced Polyurethane Foam (R-PUF) and Plywood Boxes with Perlite
B. Solid lead sheets
C. Fiber glass wool only
D. Concrete slabs

Answer: A — Reinforced Polyurethane Foam (R-PUF) and Plywood Boxes with Perlite

GTT No.96 uses perlite-filled plywood boxes, while Mark III uses reinforced polyurethane foam insulation panels.

16. What is the function of the water spray system on a gas carrier upper deck?

A. Clean the deck paintwork
B. Provide fresh drinking water to crew
C. Cool cargo tank domes, accommodation boundaries, and absorb toxic or flammable gas leaks
D. Lubricate cargo manifold connections

Answer: C — Cool cargo tank domes, accommodation boundaries, and absorb toxic or flammable gas leaks

Deck water spray systems cool structural steel boundaries and knock down soluble gas clouds (like ammonia) during emergency leaks.

17. Before gas-freeing a cargo tank that contained flammable gas, what step must be taken first?

A. Turn on electric deck heaters
B. Open all deck hatches immediately to fresh air
C. Inert the tank with Nitrogen or inert gas until hydrocarbon content is below LFL
D. Fill the tank with sea water

Answer: C — Inert the tank with Nitrogen or inert gas until hydrocarbon content is below LFL

Purging flammable gas with inert gas prevents the atmosphere inside the tank from entering the flammable range when fresh air is later introduced.

18. What is the purpose of the primary membrane in a Gaztransport membrane LNG containment system?

A. Liquid-tight barrier containing the cargo liquid
B. Outer weather deck protection
C. Thermal insulation layer only
D. Structural hull stiffener

Answer: A — Liquid-tight barrier containing the cargo liquid

The primary membrane (Invar steel or corrugated stainless steel) acts as a thin liquid-tight liquid container.

19. What device is installed on gas carrier vents to prevent flame propagation into cargo tanks?

A. Orifice plate
B. Flame screen or flame arrestor
C. Butterfly valve
D. Non-return flap

Answer: B — Flame screen or flame arrestor

Flame screens use wire gauze to dissipate heat and prevent external flames from entering gas outlets.

20. What is Custody Transfer Measurement System (CTMS) used for on an LNG carrier?

A. Monitoring crew cabin temperature
B. Tracking ship GPS position
C. Calculating engine oil consumption
D. Accurately measuring cargo volume, temperature, and pressure for financial transfer

Answer: D — Accurately measuring cargo volume, temperature, and pressure for financial transfer

CTMS measures liquid level, density, and temperature with high precision for cargo accounting and commercial billing.

21. What is the upper explosive limit (UEL) of methane in air?

A. Approximately 90%
B. Approximately 5%
C. Approximately 50%
D. Approximately 15%

Answer: D — Approximately 15%

Methane is flammable in air between its LEL of ~5% and UEL of ~15% by volume.

22. What personal protective equipment must be worn when sampling toxic liquefied gases?

A. Dust mask and safety shoes
B. Standard cotton coveralls only
C. Sunglasses and leather gloves
D. Full protective suit, SCBA or air-line respirator, and chemical-resistant gloves

Answer: D — Full protective suit, SCBA or air-line respirator, and chemical-resistant gloves

Handling or sampling toxic gases requires respiratory protection (SCBA) and chemical-proof suits to prevent inhalation or contact.

23. Which international regulation specifies the minimum standard for regulatory compliance and STCW code requirements concerning Advanced Liquefied Gas Tanker?

A. STCW Code Section A-V/1-2-2 and relevant SOLAS/MARPOL conventions
B. Tonnage Measurement Convention 1969
C. Port State Control advisory note only
D. International Load Line Certificate Annex 3

Answer: A — STCW Code Section A-V/1-2-2 and relevant SOLAS/MARPOL conventions

STCW Code Section A-V/1-2-2 sets international standards for training and operational competency in Advanced Liquefied Gas Tanker.

24. In the event of an emergency involving regulatory compliance and STCW code requirements during Advanced Liquefied Gas Tanker tasks, what immediate action is required?

A. Raise the alarm, notify the Officer of the Watch, and execute assigned muster list duties
B. Attempt to resolve the incident silently without raising the alarm
C. Wait until the end of the watch to log the issue
D. Evacuate the vessel immediately without informing the bridge

Answer: A — Raise the alarm, notify the Officer of the Watch, and execute assigned muster list duties

Prompt alarm activation ensures emergency response teams can mobilize immediately.

25. What does LPG stand for?

A. Liquefied Petroleum Gas
B. Liquefied Propylene Gasoline
C. Low Pressure Gas
D. Liquid Processed Gas

Answer: A — Liquefied Petroleum Gas

LPG stands for Liquefied Petroleum Gas, primarily consisting of propane and butane mixtures.

26. In a fully refrigerated LPG carrier, at what temperature is propane typically carried at atmospheric pressure?

A. +15°C
B. 42°C
C. 5°C
D. 162°C

Answer: B — 42°C

Commercial propane boils at -42.1°C at atmospheric pressure, making fully refrigerated LPG storage around -42°C.

27. What gas detection method is used in continuous gas monitoring systems in interbarrier spaces?

A. Infrared gas absorption analyzers
B. Litmus paper strips
C. Visual observation glass
D. Smoke detectors

Answer: A — Infrared gas absorption analyzers

Infrared gas detectors provide reliable continuous detection of hydrocarbon vapors without needing oxygen.

28. What is the function of the secondary barrier in an LNG containment system?

A. Prevent seawater entry into ballast tanks
B. Provide structural strength to the main deck
C. Hold engine exhaust gas
D. Contain cargo leakage for a specified period if the primary barrier fails

Answer: D — Contain cargo leakage for a specified period if the primary barrier fails

Under the IGC Code, a secondary barrier prevents cold liquid reaching the ship hull structure if the primary barrier leaks.

29. Why must cargo tanks be cooled down gradually before loading cryogenic liquid cargo?

A. Increase loading speed
B. Save electrical power
C. Prevent rust formation
D. Prevent excessive thermal stress and deformation of tank structure and pumps

Answer: D — Prevent excessive thermal stress and deformation of tank structure and pumps

Controlled tank cool-down limits thermal gradients, avoiding structural cracks or seal damages in tanks and piping.

30. What is the typical maximum oxygen content allowed in Nitrogen used for inerting gas tanks?

A. 8.0% by volume
B. 0.5% to 1.0% by volume
C. 15.0% by volume
D. 21.0% by volume

Answer: B — 0.5% to 1.0% by volume

High purity Nitrogen generators on gas tankers supply N2 with O2 levels below 0.5-1% to ensure complete safety.

Set 2 — 30 GASCO exit exam questions with answers

1. What safety valve is fitted on cargo lines to relieve thermal expansion of trapped liquid?

A. Foot valve
B. Vacuum breaker valve
C. Thermal relief valve
D. Storm valve

Answer: C — Thermal relief valve

Trapped cold liquid expands rapidly when warmed; thermal relief valves release small quantities to prevent pipe rupture.

2. What type of cargo compressor is commonly used in LPG reliquefaction plants?

A. Hydraulic axial pumps
B. Air jet ejectors
C. Wet rotary vane pumps
D. Oil-free screw or reciprocating compressors

Answer: D — Oil-free screw or reciprocating compressors

Reliquefaction units use oil-free compressors to avoid oil contamination of cargo liquid during condensation cycles.

3. What emergency signal activates the shipwide ESD during cargo operations?

A. VHF radio call
B. Manual ESD push button or automatic fire/high pressure trip
C. General emergency alarm bell only
D. Whistle blast on main mast

Answer: B — Manual ESD push button or automatic fire/high pressure trip

ESD pushbuttons located at manifolds, cargo control room, and bridge trigger pneumatic/electrical ESD loops.

4. What publication provides detailed safety guidelines for Tanker Safety in gas operations?

A. COLREG 1972
B. Load Line Convention
C. SIGTTO Liquefied Gas Handling Principles on Ships
D. STCW Code Section A-I/1

Answer: C — SIGTTO Liquefied Gas Handling Principles on Ships

SIGTTO guidelines (Society of International Gas Tanker and Terminal Operators) are industry standard manuals for gas tanker safety.

5. How frequently must operational drills and practical checks for regulatory compliance and STCW code requirements be conducted for Advanced Liquefied Gas Tanker?

A. At least monthly or as mandated by SOLAS and shipboard safety management system (SMS)
B. Annually prior to vessel drydocking
C. Only when requested by port State control inspectors
D. Once every 5 years during special survey

Answer: A — At least monthly or as mandated by SOLAS and shipboard safety management system (SMS)

Regular drills maintain crew emergency readiness and satisfy SOLAS requirements.

6. What documented record must be maintained on board following completion of tasks related to regulatory compliance and STCW code requirements in Advanced Liquefied Gas Tanker?

A. Verbal update to port agent without logging
B. No written record is required
C. Entry in the official Deck or Engine Logbook recording date, time, and operational parameters
D. Unsigned note on the shipboard notice board

Answer: C — Entry in the official Deck or Engine Logbook recording date, time, and operational parameters

Official logbook entries provide mandatory legal documentation of shipboard safety tasks.

7. What is the primary function of the cargo vaporizer on an LNG carrier?

A. Condense boil-off gas into liquid
B. Separate water from LNG
C. Cool down cargo piping
D. Convert LNG liquid into methane gas for cargo tank gassing-up or boiler fuel

Answer: D — Convert LNG liquid into methane gas for cargo tank gassing-up or boiler fuel

Vaporizers use steam or thermal fluid heat exchangers to vaporize liquid LNG for operational gas supply.

8. Which type of independent tank is spherical in shape and self-supporting?

A. Gaztransport Membrane Tank
B. Integral Tank Type A
C. Technigaz Mark III
D. Moss Rosenberg Type B Tank

Answer: D — Moss Rosenberg Type B Tank

Moss spherical tanks are Type B independent pressure containment vessels constructed from aluminum alloy or 9% nickel steel.

9. What is 'gassing up' in gas carrier operations?

A. Replacing inert gas in cargo tanks with cargo vapor before initial cool-down
B. Pumping bilge water out
C. Injecting air into cargo tanks
D. Venting excess gas into atmosphere

Answer: A — Replacing inert gas in cargo tanks with cargo vapor before initial cool-down

Gassing up introduces cargo gas vapor to displace inert gas, avoiding N2 freezing or contamination during subsequent liquid loading.

10. What risk occurs if water vapor is present inside an LPG cargo system before loading cargo?

A. Loss of cargo density
B. Ice and hydrate formation blocking valves, filters, and pump suctions
C. Immediate chemical explosion
D. Tank vacuum collapse

Answer: B — Ice and hydrate formation blocking valves, filters, and pump suctions

Moisture forms solid ice and hydrocarbon hydrates at low temperatures, causing severe valve and pump clogging.

11. What instrument is used to check dew point (moisture content) in inert gas?

A. Pyrometer
B. Salinometer
C. Dew point meter / Hygrometer
D. Manometer

Answer: C — Dew point meter / Hygrometer

Hygrometers measure dew point to ensure inert gas moisture content is sufficiently low (typically below -40°C to -60°C dew point).

12. What is the purpose of insulation space purging with Nitrogen on membrane LNG carriers?

A. Maintain inert atmosphere and monitor for gas leakage across primary and secondary barriers
B. Cool down the ship's engine room
C. Clean the steel plating
D. Maintain positive water pressure

Answer: A — Maintain inert atmosphere and monitor for gas leakage across primary and secondary barriers

Nitrogen sweeps through insulation spaces to keep them dry, inert, and continuously sampled by hydrocarbon gas sensors.

13. What is the minimum oxygen concentration required in air for human survival without breathing apparatus?

A. 10.0%
B. 20.9% (at least 19.5% for safe entry)
C. 5.0%
D. 50.0%

Answer: B — 20.9% (at least 19.5% for safe entry)

Normal air contains 20.9% O2. Enclosed space entry requires at least 19.5% to 21% O2 volume.

14. What safety valve opens automatically if cargo tank pressure drops below atmospheric limits?

A. Gate valve
B. Pressure relief valve
C. Globe valve
D. Vacuum relief valve

Answer: D — Vacuum relief valve

Vacuum relief valves protect thin containment tanks from mechanical collapse due to sub-atmospheric internal pressure.

15. What chemical inhibitor is added to unsaturated gas cargoes like Isoprene or VCM to prevent self-reaction?

A. Caustic soda solution
B. Polymerization inhibitor
C. Anti-freeze fluid
D. Rust converter

Answer: B — Polymerization inhibitor

Reactivity inhibitors prevent violent self-polymerization reactions during sea transit.

16. What is the purpose of a cargo hose Emergency Release Coupling (ERC)?

A. Connect different pipe diameters
B. Equalize manifold pressure
C. Speed up liquid loading rates
D. Rapidly detach loading arms/hoses without spill if the ship drifts away from berth

Answer: D — Rapidly detach loading arms/hoses without spill if the ship drifts away from berth

ERCs close dry-break valves and uncouple manifold connections instantly during severe emergency breakaway.

17. What type of personal protective equipment (PPE) is essential when handling regulatory compliance and STCW code requirements under Advanced Liquefied Gas Tanker guidelines?

A. Standard street clothing with rubber gloves
B. High-visibility vest only
C. Basic cotton coveralls without eye or foot protection
D. Certified task-specific PPE meeting SOLAS/IMO performance standards

Answer: D — Certified task-specific PPE meeting SOLAS/IMO performance standards

Approved PPE protects personnel against specific physical and chemical hazards.

18. What parameter must be verified prior to authorizing enclosed space entry for regulatory compliance and STCW code requirements related to Advanced Liquefied Gas Tanker?

A. Visual inspection through access hatch without gas testing
B. Oxygen level at 15% with ventilation turned off
C. Atmospheric oxygen level at 20.9% and zero toxic/flammable gas concentration
D. Temperature check only

Answer: C — Atmospheric oxygen level at 20.9% and zero toxic/flammable gas concentration

Enclosed space safety requires verified atmospheric gas testing prior to entry.

19. What does SIGTTO stand for?

A. Society of International Gas Tanker and Terminal Operators
B. Safety Inspection Group for Tanker Operations
C. Standard International Gas Trade Organization
D. System Integration for Gas Transport Operators

Answer: A — Society of International Gas Tanker and Terminal Operators

SIGTTO promotes safety and operational best practices in gas marine transportation and terminal handling worldwide.

20. What is the density of Methane gas compared to air at standard ambient temperature (+20°C)?

A. Heavier than air
B. Lighter than air (vapor density ~ 0.55 relative to air)
C. Heavier than lead
D. Same density as water

Answer: B — Lighter than air (vapor density ~ 0.55 relative to air)

Methane gas at ambient temperature is lighter than air (~0.55 SG) and disperses upward quickly. Cold methane (-162°C) is initially heavier than air.

21. What type of fire extinguishing agent is most effective on gas cargo manifold fires?

A. Seawater jet directly
B. Sand buckets
C. Foam blanket
D. Dry Chemical Powder (DCP)

Answer: D — Dry Chemical Powder (DCP)

DCP systems (Potassium Bicarbonate/Sodium Bicarbonate) extinguish gas flame jets rapidly by inhibiting chemical chain reaction.

22. Under the IGC Code, what is the maximum filling limit for liquid gas cargo tanks?

A. 80% maximum
B. 50% only
C. Typically 98% at reference temperature to allow thermal expansion
D. 100% full to top

Answer: C — Typically 98% at reference temperature to allow thermal expansion

Filling limits are calculated (usually ~98% max) to ensure liquid expansion does not fill the tank completely 100% liquid-full.

23. What is the function of the cargo heater on a gas tanker?

A. Heat drinking water for crew
B. Warm cold liquid cargo during discharge to atmospheric pressure shore tanks
C. Boil cargo inside cargo tanks
D. Melt ice on ship anchor

Answer: B — Warm cold liquid cargo during discharge to atmospheric pressure shore tanks

Cargo heaters use seawater to warm cold liquid LPG before delivering it to uninsulated pressurized shore storage tanks.

24. What safety document must be completed jointly by ship and shore representatives before starting gas cargo transfer?

A. Crew List
B. Certificate of Registry
C. SSSCL (Ship/Shore Safety Checklist)
D. Bill of Lading

Answer: C — SSSCL (Ship/Shore Safety Checklist)

The ISGOTT/SIGTTO Ship/Shore Safety Checklist ensures all safety controls, ESD links, and emergency communications are verified.

25. What is the primary cause of cold spot formation on the outer hull plating near an LNG tank?

A. Insulation failure or leak in cargo containment
B. Strong wind blowing
C. High seawater salinity
D. Paint discoloration

Answer: A — Insulation failure or leak in cargo containment

Cold spots indicate breakdown in insulation performance, causing hull steel temperature to drop below safe design limits.

26. What protective atmosphere is maintained inside the void spaces of Type A independent LPG tanks?

A. Seawater
B. Steam
C. Dry inert gas or dry air
D. Pure oxygen

Answer: C — Dry inert gas or dry air

Void spaces surrounding Type A tanks are kept dry with inert gas or dry air to prevent corrosion and detect leaks.

27. What device measures cargo level continuously in an LNG membrane tank using radar waves?

A. Radar ullage level gauge
B. Sounding tape
C. Float gauge
D. Sight glass tube

Answer: A — Radar ullage level gauge

Non-contact microwave radar level gauges provide accurate non-mechanical ullage measurements inside cryogenic tanks.

28. What condition requires immediate stopping of gas cargo operations?

A. Electrical storm / lightning in immediate vicinity, ESD failure, or gas leak detected
B. Sunrise
C. Change of watchman
D. Meal time announcement

Answer: A — Electrical storm / lightning in immediate vicinity, ESD failure, or gas leak detected

Lightning storms, cargo leaks, or ESD failures pose immediate fire/explosion risks requiring instant operational shutdown.

29. What key responsibility belongs to seafarers performing watchkeeping duties for regulatory compliance and STCW code requirements under Advanced Liquefied Gas Tanker?

A. Continuous monitoring of operational parameters and immediate reporting of anomalies
B. Bypassing safety trips during routine operations
C. Leaving watchkeeping station unattended
D. Operating equipment beyond design pressure limits

Answer: A — Continuous monitoring of operational parameters and immediate reporting of anomalies

Continuous vigilance and prompt communication are core watchkeeping duties under STCW.

30. Which document contains detailed hazard data and emergency handling instructions for substances involved in regulatory compliance and STCW code requirements during Advanced Liquefied Gas Tanker?

A. Safety Data Sheet (SDS) / Material Safety Data Sheet (MSDS)
B. Ship's Cargo Manifest summary page
C. Bill of Lading description
D. Crew List document

Answer: A — Safety Data Sheet (SDS) / Material Safety Data Sheet (MSDS)

Safety Data Sheets provide critical hazard identification, PPE requirements, and first aid response steps.

Set 3 — 30 GASCO exit exam questions with answers

1. Deep well pump shaft bearing are cooled and lubricated by liquid

A. Cargo being pumped
B. Hydraulic oil
C. Greas
D. Inert gas

Answer: A — Cargo being pumped

Submerged / deepwell cargo pumps in liquefied gas carriers utilize the liquid cargo being pumped to lubricate and cool the pump bearings and motor windings.

2. The study of behaviour of matter at low temperature is called

A. Seismology
B. Hydrograph
C. Cryogenics
D. Ecology

Answer: C — Cryogenics

Cryogenics is the branch of physics and engineering that studies the production and behavior of materials at extremely low cryogenic temperatures (below -150°C / 123 K).

3. Fixed gas detection system alarms should be activated when the vapour concentration reaches

A. 20
B. 5
C. 30
D. 60

Answer: B — 5

Fixed gas detection systems on gas tankers are typically set to alarm at 30% LEL in non-enclosed spaces or 5% LEL to 20% LEL depending on zone requirements and sampling configurations.

4. A device fitted in gas vent pipeline to arrest the passage of flame Into enclosed space

A. Flame arrestor
B. Explosion proof
C. Flame screen
D. Gas fr

Answer: A — Flame arrestor

A flame arrestor is a safety device fitted in vent lines and pipework designed to prevent the passage of flame into enclosed spaces or cargo tanks by dissipating heat across metallic elements.

5. Chemical combination of flammable substance with oxygen is called

A. Explosion
B. Auto ignition
C. Combustion
D. None of the abov

Answer: C — Combustion

The correct answer is Combustion. This complies with established gas tanker operational standards, thermodynamics, and the IGC Code safety requirements.

6. Which cargo operation are to be recorded in cargo record book :

A. All bunker operations
B. All petroleum cargo operations
C. All cargo operations involving NLS
D. All cargo operations

Answer: D — All cargo operations

Under MARPOL regulations and gas tanker protocols, all cargo and ballast operations involving liquefied gases or noxious liquid substances must be documented in the Cargo Record Book.

7. When cargo carried as liquid in cargo tanks and not shipped in drums , containers , or packages , what are they called as

A. Liquid cargo
B. Tank cargo
C. Oil cargo
D. Bulk cargo

Answer: D — Bulk cargo

Cargoes loaded directly into ship tanks without intermediate packaging, drums, or containers are classified as bulk liquid cargoes.

8. Gas ship accommodation and machinery space are :

A. Hazardous area
B. Gas saf
C. Gas dangerous
D. All the abov

Answer: B — Gas saf

Accommodation spaces, engine rooms, and service spaces outside the cargo area are designated as Gas Safe areas provided they are properly segregated and maintained at positive pressure.

9. What is the hazards – reactivity when cargo reacts with water called

A. Hydrate formation
B. Polymerization
C. Toxic vapour
D. None of the abov

Answer: A — Hydrate formation

Hydrate formation occurs when light hydrocarbons (like methane, ethane, propane) combine with free water at low temperatures and high pressures, forming solid ice-like crystalline compounds that can block valves and pipework.

10. Fire fighting technique with a pool fire is to sweep

A. Side to sid
B. Front to back
C. Both A and B
D. None of the abov

Answer: C — Both A and B

When tackling a liquefied gas pool fire with dry chemical powder, the recommended nozzle technique is to sweep side-to-side and advance from front-to-back to extinguish the base of the flame.

11. The mass of a Vapour compared with the mass of an equal volume of air both at standard condition to temp and pressure is

A. Relative liquid density
B. Relative vapour density
C. Relative density
D. None of the abov

Answer: B — Relative vapour density

The correct answer is Relative vapour density. This complies with established gas tanker operational standards, thermodynamics, and the IGC Code safety requirements.

12. Changing of cargo which may involve

A. Only gas freeing
B. Only inerting
C. Only gassing up
D. All of the abov

Answer: D — All of the abov

A complete change of cargo grades on a gas tanker typically involves stripping/warming up, inerting, gas freeing, aerating (if required), and subsequent gassing up/cooling down.

13. On which type of cargo tank would you find a bimetallic joint or STJ

A. Kvaerner Moss Type B
B. Gas transport membrane
C. Type C
D. Prismatic Type A

Answer: A — Kvaerner Moss Type B

In Kvaerner Moss Type B spherical tank systems, a structural transition joint (STJ or bimetallic joint) connects the aluminum alloy sphere to the stainless/carbon steel supporting skirt.

14. If the cargo density is different from that specified the float gauge manufacturer what will you adjust

A. Float correction
B. Trim correction
C. List correction
D. Tape correction

Answer: A — Float correction

The correct answer is Float correction. This complies with established gas tanker operational standards, thermodynamics, and the IGC Code safety requirements.

15. The frequency of pressure testing ashore of BA set should at least every

A. 6 years
B. 5 years
C. 10 years
D. 15 years

Answer: B — 5 years

Self-Contained Breathing Apparatus (SCBA/BA) cylinders must undergo periodic hydraulic pressure testing ashore at least once every 5 years in compliance with SOLAS and class rules.

16. What is the guiding rule for limiting pressure surge on loading or discharging

A. Stop the cargo pump
B. First close ESD valve nearest to the pump
C. Finally close other ESD valv
D. All the abov

Answer: D — All the abov

To minimize hydraulic pressure surge (liquid hammer), ESD valves and pumps follow sequenced shut-down protocols.

17. The ventilation of the airlock should be of the ______ pressure type

A. Negativ
B. Positiv
C. Neutral
D. None of the abov

Answer: B — Positiv

Airlocks providing access between gas-dangerous and gas-safe zones are maintained at positive relative air pressure to prevent vapor ingress into the safe area.

18. Why is it necessary to cool down cargo tanks (refrigerated ships) during bulk loading

A. To avoid overflow
B. To avoid vapors emission
C. To avoid vacuum in cargo tank
D. To avoid excessive tank pressure

Answer: D — To avoid excessive tank pressure

Pre-cooling refrigerated cargo tanks avoids thermal shock, violent flashing, and excessive tank pressure increases during bulk loading.

19. An overdose of toxic petroleum vapour effects your sense of smell by

A. Reducing it temporarily
B. Taking it away completely
C. Improving it temporarily
D. Improving it permanently

Answer: B — Taking it away completely

High concentrations of hydrocarbon vapors and toxic compounds (like H2S) rapidly cause olfactory fatigue, completely deadening the sense of smell.

20. All liquefied gases produces vapours which have a relative vapour density greater than that of

A. Methan
B. Methane and ethylen
C. Methane, ethylene and ammonia
D. None of the abov

Answer: A — Methan

Relative vapor density is the ratio of the mass of a specific volume of gas/vapor compared to an equal volume of dry air at standard temperature and pressure.

21. Gas codes and classification society rules require every tank to be fitted at least _____ level gauge

A. On
B. Two
C. Thr
D. Four

Answer: B — Two

Under the IGC Code (Chapter 13), each cargo tank must be fitted with at least two independent level gauging devices.

22. The concentration of a hydrocarbon gas is air below which there is insufficient hydrocarbon is called

A. Lower flammable limit
B. Dry air
C. Upper flammable limit
D. Stoichiometric ratio

Answer: A — Lower flammable limit

The Lower Flammable Limit (LFL/LEL) is the minimum concentration of flammable gas/vapor in air below which the mixture is too lean to ignite.

23. After stopping the cargo compressor, the glycol/water system is left running to provide

A. Crank case heating
B. Remove cargo vapours
C. Both a and b
D. None of the abov

Answer: C — Both a and b

After shutting down cargo compressors, the glycol-water heating circuit is maintained to provide crankcase heating and prevent condensation or migration of cargo vapors.

24. Fixed water spray system for fire protection purpose in gas tanker covers area such as

A. Cargo tanks domes only
B. The front of the accommodation and control room bulkhead
C. Cargo tank area above deck and cargo manifold area
D. All the abov

Answer: D — All the abov

Fixed water spray systems on gas carriers provide boundary cooling for cargo tank domes, deck piping, manifolds, and accommodation forward bulkheads.

25. When carbon atoms joined by double covalent bonds C-C or triple covalent bonds, what is it called as

A. Saturated organic compound
B. Unsaturated organic compound
C. Both a and b
D. None of the abov

Answer: B — Unsaturated organic compound

Hydrocarbons containing double (C=C) or triple (C≡C) carbon-carbon bonds (such as ethylene and propylene) are classified as unsaturated organic compounds.

26. What is liquid relative density at atmospheric boiling point of methane

A. 0.427
B. 144
C. 195.7
D. None of the abov

Answer: A — 0.427

Methane has a liquid relative density of approximately 0.427 at its atmospheric boiling point of -161.5°C.

27. The ability of a substance to cause damage to living tissue or impairment of the central nervous system

A. Asphyxia
B. Frost bit
C. Toxicity
D. None of the abov

Answer: C — Toxicity

Toxicity is the inherent property of a substance to cause biological damage to living tissue, systemic poisoning, or impairment of the central nervous system.

28. How suction capacity and resulting discharge rate can be regulated

A. By reducing pump speed
B. By throttling the discharge valv
C. By creating bypass (return flow)
D. All the abov

Answer: D — All the abov

Centrifugal cargo pump discharge rate can be regulated by varying motor/turbine speed, throttling the discharge valve, or utilizing recirculating bypass lines.

29. What are the necessary condition that must take place for an electrical discharge to occur

A. Electrostatic separation
B. Electrostatic accumulation
C. Electrostatic discharg
D. All the abov

Answer: D — All the abov

The correct answer is All the abov. This complies with established gas tanker operational standards, thermodynamics, and the IGC Code safety requirements.

30. Gas ships cargo compressor room, cargo tank area are

A. Snap back area
B. Gas safe area
C. Gas dangerous
D. All the abov

Answer: C — Gas dangerous

The correct answer is Gas dangerous. This complies with established gas tanker operational standards, thermodynamics, and the IGC Code safety requirements.

Set 4 — 30 GASCO exit exam questions with answers

1. What does Exe represents

A. Flameproof
B. Pressurized
C. Increased safety
D. None of the abov

Answer: C — Increased safety

The Ex 'e' electrical marking designates 'Increased Safety' explosion-protection construction under IEC/CENELEC standards.

2. Onboard LNG tanker which of these requirements is not required for gas burning

A. Vacuum pump
B. Gas heater
C. LD compressor
D. Steam dump on main condenser

Answer: A — Vacuum pump

LNG boil-off gas burning systems utilize LD compressors, gas heaters, and main boiler steam dump systems; vacuum pumps are not part of the fuel gas supply train.

3. What is provided in a low duty gas compressor to prevent lubricating oil mist from entering the compressed LNG vapour ?

A. The gas detection system
B. The gas burning system
C. c. The lubricating system
D. The seal gas system

Answer: D — The seal gas system

A nitrogen seal gas system is fitted on LNG boil-off gas compressors to prevent lubricating oil mist from contaminating the compressed vapor and prevent gas leakage along shaft seals.

4. What is the first task to be completed before doing hot work permit.

A. To inform chief engineer
B. Work can be started without carrying out any other task
C. To complete a hot work permit
D. None of the abov

Answer: C — To complete a hot work permit

Before initiating hot work, a comprehensive hot work permit and risk assessment must be completed, verifying atmosphere tests, safety measures, and formal authorization.

5. The most like place for the spontaneous combustion that take place is

A. The oily rag bin
B. The fuel oil tanks
C. The electrical switch boards
D. The pressuree tanks

Answer: A — The oily rag bin

Oily rags stored in confined bins can undergo slow exothermic oxidation, leading to thermal accumulation and spontaneous combustion.

6. Which of the following is not part of an arrangement in fiber optical system to accommodate 'fail safe' ESDS system

A. The photo coupler of the input side are duplicated
B. Frequency checking sides of O/P are duplicated
C. The optical cables are protected by double layer of insulations
D. The output circuits has double output contacts

Answer: C — The optical cables are protected by double layer of insulations

ESDS automatic fusible thermal elements are designed to melt between 98°C and 104°C during a fire, depressurizing the pneumatic loop and tripping the emergency shutdown system.

7. Up to what temperature is methane vapour heavier than air

A. -110C
B. -161 .5C
C. -125C
D. 15C

Answer: A — -110C

Cold methane vapor at temperatures below -110°C is denser/heavier than ambient air (15°C) and will stay low or form a dense white cloud until warmed above -110°C.

8. What is the typical content of carbon dioxide in inert gas produced by an inert gas generator

A. 25%
B. 15%
C. 20%
D. 30%

Answer: B — 15%

Typical combustion-based marine inert gas generators produce inert gas consisting of ~14-15% CO2, <0.5-1% O2, with the remainder (~84-85%) being nitrogen.

9. A water repellant such as _____ is added in order to avoid humidity in the power

A. Sulphur
B. Silicon
C. Calcium
D. None of the abov

Answer: B — Silicon

Silicon additives and metal stearates are added to dry chemical powders as water repellents to prevent moisture caking and maintain fluid powder discharge.

10. What does the term boil off mean

A. Cargo vapour space in insulation spac
B. Natural vapourization of LNG in the cargo tank
C. Cargo tank vapour pressuree during voyag
D. Excess steam dumped from the boiler

Answer: B — Natural vapourization of LNG in the cargo tank

Boil-Off Gas (BOG) is the continuous natural vaporization of cryogenic liquefied gas (like LNG at -161.5°C) caused by ambient heat ingress through the cargo tank insulation.

11. Why LNG is liquefied for sea transportation

A. LNG has high calorific value than natural gas
B. Natural gas transportation by sea is banned
C. It makes it more economical to transport
D. The ship can choose the form of neutral gas or LNG to be loaded

Answer: C — It makes it more economical to transport

Liquefying natural gas reduces its volume by approximately 600 times, making long-distance maritime bulk transportation commercially and technically viable.

12. Which of the following is the typical seal gas system used for low duty gas compressor ?

A. R 404
B. Carbon dioxid
C. Nitrogen
D. Argon

Answer: C — Nitrogen

A nitrogen seal gas system is fitted on LNG boil-off gas compressors to prevent lubricating oil mist from contaminating the compressed vapor and prevent gas leakage along shaft seals.

13. The purpose of remotely controlled measuring of tank levels are to measure

A. Height from liquid surface to top stringers in the tank
B. Height of the liquid in the tank
C. Height from bottom shell to top stringers in the tank
D. Height of bottom girders in the tank

Answer: B — Height of the liquid in the tank

The correct answer is Height of the liquid in the tank. This complies with established gas tanker operational standards, thermodynamics, and the IGC Code safety requirements.

14. One of the following is NOT an alarm on an inert gas plant, which one?

A. Low pressuree alarm
B. Low oxygen Alarm
C. Deck sea Low water Alarm
D. Scrubber high water level alarm

Answer: B — Low oxygen Alarm

The correct answer is Low oxygen Alarm. This complies with established gas tanker operational standards, thermodynamics, and the IGC Code safety requirements.

15. On all gas ships, any pipework entering or leaving the cargo tank must do so through the ____ of the tank

A. Aft end
B. Top
C. Bottom
D. Forward end

Answer: B — Top

The correct answer is Top. This complies with established gas tanker operational standards, thermodynamics, and the IGC Code safety requirements.

16. If a centrifugal pump operating with a positive suction head becomes air bound, your FIRST response should be to _____

A. Vent the casting
B. Tighten the packing
C. Close the discharg
D. Re-prime the pump

Answer: A — Vent the casting

The correct answer is Vent the casting. This complies with established gas tanker operational standards, thermodynamics, and the IGC Code safety requirements.

17. How much cleaner is natural gas to burn?

A. Reducing Carbon Dioxide (CO2) emissions by 20% to 30%
B. Reducing carbon monoxide (CO) emissions up to 75%
C. Reducing nitrous oxide (NO2) emission by appropriately 50%
D. All the abov

Answer: A — Reducing Carbon Dioxide (CO2) emissions by 20% to 30%

The correct answer is Reducing Carbon Dioxide (CO2) emissions by 20% to 30%. This complies with established gas tanker operational standards, thermodynamics, and the IGC Code safety requirements.

18. Self contained breathing apparatus – SCBA is also called as

A. Compressed air breathing apparatus – CABA
B. EEBD
C. ELSA
D. None of the abov

Answer: A — Compressed air breathing apparatus – CABA

The correct answer is Compressed air breathing apparatus – CABA. This complies with established gas tanker operational standards, thermodynamics, and the IGC Code safety requirements.

19. The space enclosed by the ships structure in which a cargo Containment system is situated called ______

A. Hold spac
B. Compressor room
C. Motor room
D. Engine room

Answer: A — Hold spac

The correct answer is Hold spac. This complies with established gas tanker operational standards, thermodynamics, and the IGC Code safety requirements.

20. This liquefied gas is normally carried in its fully refrigerated condition at its atmospheric boiling point of -104 °C is ______

A. Ethylen
B. Propan
C. Butan
D. Ammonia

Answer: A — Ethylen

The correct answer is Ethylen. This complies with established gas tanker operational standards, thermodynamics, and the IGC Code safety requirements.

21. How is cooling/Cleaning water supplied to the inert gas scrubber tower?

A. By the main sea water pumps
B. By the cargo condenser pump
C. By the scrubber sea water pump
D. By the deck seal sea water pump

Answer: C — By the scrubber sea water pump

The correct answer is By the scrubber sea water pump. This complies with established gas tanker operational standards, thermodynamics, and the IGC Code safety requirements.

22. Which safety device is fitted on the deck inert gas line to monitor the supply condition of the inert gas?

A. The inert gas high temperature alarm
B. The inert gas low flow alarm
C. The inert gas low pressuree alarm
D. The inert gas reverse flow alarm

Answer: C — The inert gas low pressuree alarm

The correct answer is The inert gas low pressuree alarm. This complies with established gas tanker operational standards, thermodynamics, and the IGC Code safety requirements.

23. What characteristics should insulation materials possess for use in gas carriers?

A. Low thermal conductivity, ability to bear loads
B. Ability to with stand mechanical damagee, lightweight
C. Unaffected by cargo liquid or vapour
D. All the abov

Answer: D — All the abov

The correct answer is All the abov. This complies with established gas tanker operational standards, thermodynamics, and the IGC Code safety requirements.

24. Which of the following is the ultimate source of energy for us?

A. LNG
B. Nuclear
C. Solar
D. CNG

Answer: C — Solar

The correct answer is Solar. This complies with established gas tanker operational standards, thermodynamics, and the IGC Code safety requirements.

25. Why strainers are commonly installed in the cargo piping system?

A. To protect the cargo handling plant
B. To protect equipment from damagee by foreign objects
C. Both A and B
D. None of the abov

Answer: C — Both A and B

The correct answer is Both A and B. This complies with established gas tanker operational standards, thermodynamics, and the IGC Code safety requirements.

26. Which of these would you consider essential equipment to carry when working on the deck of ship carrying ammonia?

A. Gloves
B. Personal O meter
C. Gas mask
D. Personal Hydrocarbon alarm

Answer: C — Gas mask

The correct answer is Gas mask. This complies with established gas tanker operational standards, thermodynamics, and the IGC Code safety requirements.

27. What is the condition of inert gas as it is produced by the boilers or inert gas generator?

A. Free of oxygen and clean
B. Hot and containing soot particles
C. Dirty and saturated
D. Super heated and black or greyish in colour

Answer: A — Free of oxygen and clean

The correct answer is Free of oxygen and clean. This complies with established gas tanker operational standards, thermodynamics, and the IGC Code safety requirements.

28. For what reason cargo sampling is necessary in gas tanker?

A. To establish safe conditions prior to cargo transfer
B. To establish that the cargo is within commercially agreed specifications at various Pumps
C. Both A and B
D. None of the abov

Answer: C — Both A and B

The correct answer is Both A and B. This complies with established gas tanker operational standards, thermodynamics, and the IGC Code safety requirements.

29. What is the MAIN danger to be guarded against when discharging using a cargo heater with sea water as the heating medium?

A. Over pressureizing of the gas side of the water
B. Freezing of the water side of the heater
C. Over pressureizing of the water side of the heater
D. Overheating of the gas side of the heater

Answer: B — Freezing of the water side of the heater

The correct answer is Freezing of the water side of the heater. This complies with established gas tanker operational standards, thermodynamics, and the IGC Code safety requirements.

30. Magnesium, Titanium, Sodium, Lithium and Potassium are classified as

A. Class A fir
B. Class B fir
C. Class C fir
D. Class D fir

Answer: D — Class D fir

The correct answer is Class D fir. This complies with established gas tanker operational standards, thermodynamics, and the IGC Code safety requirements.

Set 5 — 30 GASCO exit exam questions with answers

1. What are the symptoms of Asphyxiant , when LPG and LNG carried as cargo?

A. Increased rate and dept of respiration and loss of consciousness
B. Blueness of the skin (Cyanosis)
C. Stertorous breathing with a snoring sound
D. All of the abov

Answer: D — All of the abov

The correct answer is All of the abov. This complies with established gas tanker operational standards, thermodynamics, and the IGC Code safety requirements.

2. Inert gas- How is sea water supplied to the deck seal ?

A. Through the main sea water pumps or through the condenser cargo pump
B. Through a sea water aggregate pump fitted on the cargo deck
C. Through the deck fire lin
D. Through the deck seal pump fitted in the engine room

Answer: D — Through the deck seal pump fitted in the engine room

The correct answer is Through the deck seal pump fitted in the engine room. This complies with established gas tanker operational standards, thermodynamics, and the IGC Code safety requirements.

3. On tank vessels, which of these valve types is most commonly used in conjunction with hydraulically actuated controls?

A. Non return valves
B. Globe valves
C. Butterfly valves
D. Gate valves

Answer: C — Butterfly valves

The correct answer is Butterfly valves. This complies with established gas tanker operational standards, thermodynamics, and the IGC Code safety requirements.

4. What is critical temperature of methane in °Celsius ?

A. -82.5
B. 82.5
C. 52.8
D. None of the abov

Answer: A — -82.5

The correct answer is -82.5. This complies with established gas tanker operational standards, thermodynamics, and the IGC Code safety requirements.

5. On tank vessels equipped with the power operated cargo tank valves, the type of power operator most commonly used is _____

A. Hydraulic
B. Electric
C. Steam
D. Diesel

Answer: A — Hydraulic

The correct answer is Hydraulic. This complies with established gas tanker operational standards, thermodynamics, and the IGC Code safety requirements.

6. The valve best suited for throttling gas or liquid flow in a pipe line is the _____

A. Globe valv
B. Gate valv
C. Check valv
D. Pug cock

Answer: A — Globe valv

The correct answer is Globe valv. This complies with established gas tanker operational standards, thermodynamics, and the IGC Code safety requirements.

7. What is the boiling point at atmospheric pressure of ammonia

A. -42 °Celsius
B. -34 °Celsius
C. -5 °Celsius
D. None of the abov

Answer: B — -34 °Celsius

Anhydrous ammonia (NH3) has an atmospheric boiling point of -33.4°C (approximately -34°C).

8. Which tanks are completely supported self-supporting and do not form part of the ship's hull structure

A. Independent tanks
B. Membrane tank
C. Semi membranee tank
D. None of the abov

Answer: A — Independent tanks

The correct answer is Independent tanks. This complies with established gas tanker operational standards, thermodynamics, and the IGC Code safety requirements.

9. Ammonia forms explosive compounds with

A. Mercury alon
B. Mercury, chlorine, iodine, bromine, calcium, silver oxide and silver hypo chlorit
C. Silica
D. Water

Answer: B — Mercury, chlorine, iodine, bromine, calcium, silver oxide and silver hypo chlorit

The correct answer is Mercury, chlorine, iodine, bromine, calcium, silver oxide and silver hypo chlorit. This complies with established gas tanker operational standards, thermodynamics, and the IGC Code safety requirements.

10. A bigger spell of LPG will be visible as a _____ which is condensed water vapour from the atmosphere

A. White cloud
B. Blue cloud
C. Black cloud
D. None of the abov

Answer: A — White cloud

The correct answer is White cloud. This complies with established gas tanker operational standards, thermodynamics, and the IGC Code safety requirements.

11. How is BOIL OFF gas generated

A. Evaporation
B. Heat ingress
C. Drop in pressure
D. All of the abov

Answer: D — All of the abov

Boil-Off Gas (BOG) is the continuous natural vaporization of cryogenic liquefied gas (like LNG at -161.5°C) caused by ambient heat ingress through the cargo tank insulation.

12. In addition to water detection sensors fitted at secondary insulation spaces, which is the other typical sensing devices fitted to give an early indication of inner hull experiencing structural failure?

A. Water moisture detector inside primary insulation spac
B. Water moisture detector at the vapor dom
C. Water moisture detector inside secondary insulation spac
D. Water moisture detector inside wing ballast tank

Answer: C — Water moisture detector inside secondary insulation spac

The correct answer is Water moisture detector inside secondary insulation spac. This complies with established gas tanker operational standards, thermodynamics, and the IGC Code safety requirements.

13. Which of the following can lead to major leak of insulation spaces?

A. Due to hair line cracks inside membranee.
B. Due to significant fatigue cracks on welds of cargo tank membranees
C. The gradual increase of methane content inside the insulation spac
D. Due to accidentally tripped of both HD and LD compressors

Answer: B — Due to significant fatigue cracks on welds of cargo tank membranees

The correct answer is Due to significant fatigue cracks on welds of cargo tank membranees. This complies with established gas tanker operational standards, thermodynamics, and the IGC Code safety requirements.

14. Which of the following equipment is not used to lift an auxiliary cargo pump?

A. Electrical connection box
B. Chain block
C. Overhead railing
D. Manifold spool piece derrick

Answer: D — Manifold spool piece derrick

The correct answer is Manifold spool piece derrick. This complies with established gas tanker operational standards, thermodynamics, and the IGC Code safety requirements.

15. What will happen to the liquid level within and pressure of a cargo tank when there is a big crack (major leak) in the cargo tank's primary membrane and adjacent insulation space, underneath the cargo level?

A. The liquid level will increase and pressuree will suddenly increas
B. The liquid level will drop and pressuree will suddenly drop
C. The liquid level will drop and pressuree will suddenly ris
D. The liquid level will increase and pressuree will be suddenly drop

Answer: C — The liquid level will drop and pressuree will suddenly ris

In Gaztransport & Technigaz NO 96 membrane containment systems, Invar membranes and perlite insulation boxes maintain cargo containment and thermal insulation.

16. Onboard an LNG carrier, with NO 96 containment system, what is the maximum allowable differential head between the cargo tank and primary spaces liquid level during discharge operation from the damaged tank?

A. 100 mm of cargo level
B. 500 mm of cargo level
C. 50 mm of cargo level
D. 10 mm of cargo level

Answer: B — 500 mm of cargo level

In Gaztransport & Technigaz NO 96 membrane containment systems, Invar membranes and perlite insulation boxes maintain cargo containment and thermal insulation.

17. In the event of major LNG spill which of the following action should not to be taken?

A. Stop cargo operation
B. Inject cargo line with CO2, without stopping the cargo operation
C. Close all accommodation doors and ventilation fans
D. Start the deck water spray (or IMO) pump

Answer: B — Inject cargo line with CO2, without stopping the cargo operation

The correct answer is Inject cargo line with CO2, without stopping the cargo operation. This complies with established gas tanker operational standards, thermodynamics, and the IGC Code safety requirements.

18. What is the method used to prevent any further lowering of the hull steel temperature due to damaged insulation?

A. By flooding the ballast tanks with CO2 around the affected cargo tank
B. By sending ship's crew to scaling off the ice formed on the surfaces of the hull steel
C. By injecting nitrogen gas inside the ballast tanks around the affected cargo tank
D. By flooding ballast tanks with sea water around any affected cargo tank

Answer: D — By flooding ballast tanks with sea water around any affected cargo tank

The correct answer is By flooding ballast tanks with sea water around any affected cargo tank. This complies with established gas tanker operational standards, thermodynamics, and the IGC Code safety requirements.

19. Which is the melting point temperature of the ESDS automatic fusible element normally fitted onboard?

A. Between 200°C to 206°C
B. Between 50°C to 55°C
C. Between 72°C to 78°C
D. Between 98°C to 104°C

Answer: D — Between 98°C to 104°C

ESDS automatic fusible thermal elements are designed to melt between 98°C and 104°C during a fire, depressurizing the pneumatic loop and tripping the emergency shutdown system.

20. Identify the odd one. Onboard an LNG tanker with NO 96 containment system, which of the following is not a typical early indication of a major cargo leak into the insulation spaces?

A. There will be a rapid increase of methane content in affected areas
B. Relief valve for the affected primary space may lift
C. Inner hull temperature will drop in affected areas
D. There will be cold spots at the ship side close to the affected area

Answer: D — There will be cold spots at the ship side close to the affected area

In Gaztransport & Technigaz NO 96 membrane containment systems, Invar membranes and perlite insulation boxes maintain cargo containment and thermal insulation.

21. Which of the following portable gas meters is used to monitor methane content during the inerting operation prior aerating?

A. M2 test tub
B. Hygrometer
C. Oxygen meter
D. Gas scop

Answer: D — Gas scop

The correct answer is Gas scop. This complies with established gas tanker operational standards, thermodynamics, and the IGC Code safety requirements.

22. Onboard a membrane class LNG tanker, during purging cargo tanks with LNG, where is the sampling point for taking the gas readings?

A. Vaporiser outlet sample cock
B. Heater outlet sample cock
C. Vapor line sample cock
D. At cargo tank loading line sample cock

Answer: D — At cargo tank loading line sample cock

In Gaztransport & Technigaz NO 96 membrane containment systems, Invar membranes and perlite insulation boxes maintain cargo containment and thermal insulation.

23. Onboard an LNG tanker, why is forced boil - off required out during loaded passage?

A. To maintain cargo tank pressurees
B. To maintain cargo tank temperatures
C. To maintain cold temperature at the tripod mast
D. To supplement fuel supply to the main propulsion plant

Answer: D — To supplement fuel supply to the main propulsion plant

The correct answer is To supplement fuel supply to the main propulsion plant. This complies with established gas tanker operational standards, thermodynamics, and the IGC Code safety requirements.

24. If there is an interruption at the end of cooldown before loading, what is the recommended measure to be taken?

A. To stop cooldown completely and open loading valv
B. To stop cooldown and close the vapor manifold
C. To start own spray pump and cool down
D. To continue cooldown process until the tank bottom close to -160°C.

Answer: D — To continue cooldown process until the tank bottom close to -160°C.

The correct answer is To continue cooldown process until the tank bottom close to -160°C.. This complies with established gas tanker operational standards, thermodynamics, and the IGC Code safety requirements.

25. Can ballast operations take place during custody transfer measurement?

A. Yes, ballasting should be done to maintain even keel
B. Ship should be maintained upright by ballasting
C. No; all ballast operations should be suspended
D. There are no restrictions on ballast operations

Answer: C — No; all ballast operations should be suspended

The correct answer is No; all ballast operations should be suspended. This complies with established gas tanker operational standards, thermodynamics, and the IGC Code safety requirements.

26. What is the medium used for inerting cargo tanks?

A. Oxygen
B. Inert gas
C. Dry air
D. Methan

Answer: B — Inert gas

The correct answer is Inert gas. This complies with established gas tanker operational standards, thermodynamics, and the IGC Code safety requirements.

27. What is the main reason for a membrane class LNG tanker to retain a small quantity of cargo ("heel") during ballast passage?

A. To ensure easy starting of cargo pump at loading port
B. To reduce the consumption of heavy fuel oil on passage
C. To avoid bottom of the cargo tank come into contact with oxygen
D. For cold maintenance of the cargo tanks

Answer: D — For cold maintenance of the cargo tanks

In Gaztransport & Technigaz NO 96 membrane containment systems, Invar membranes and perlite insulation boxes maintain cargo containment and thermal insulation.

28. Which equipment Is used for evacuating the Insulation spaces?

A. Vacuum pumps
B. HD blowers
C. LD blowers
D. Water ballast ejector

Answer: A — Vacuum pumps

The correct answer is Vacuum pumps. This complies with established gas tanker operational standards, thermodynamics, and the IGC Code safety requirements.

29. Safety is dependent on orderliness and cleanliness. Order may be maintained by______.

A. storing items in their assigned plac
B. storing all items in a common storage container except those ready-for-sea
C. tagging all items according to their age and then storing them together
D. disposing of used items

Answer: A — storing items in their assigned plac

The correct answer is storing items in their assigned plac. This complies with established gas tanker operational standards, thermodynamics, and the IGC Code safety requirements.

30. Oxygen in the atmosphere of the tank is used up when iron is converted into oxides during the corrosion process. ---------------i in the tanks prior to entry.

A. Copious quantity of fresh air
B. Space to have a minimum oxygen level for sustaining lif
C. Pressurized oxygen pumped
D. Space to be ventilated for 24 hours

Answer: B — Space to have a minimum oxygen level for sustaining lif

The correct answer is Space to have a minimum oxygen level for sustaining lif. This complies with established gas tanker operational standards, thermodynamics, and the IGC Code safety requirements.

Set 6 — 30 GASCO exit exam questions with answers

1. gas pressurizes the liquid out of the soda acid type- water extinguisher through the dip tube.

A. hydrogen
B. oxygen
C. nitrogen
D. carbon-dioxid

Answer: D — carbon-dioxid

Soda-acid fire extinguishers use a solution of sodium bicarbonate in water that reacts with sulfuric acid to generate carbon dioxide expellant gas for Class A fires.

2. Good housekeeping on a vessel prevents fires by

A. allowing better access in an emergency
B. eliminating potential fuel sources
C. eliminating trip hazards
D. improving personnel qualifications

Answer: B — eliminating potential fuel sources

The correct answer is eliminating potential fuel sources. This complies with established gas tanker operational standards, thermodynamics, and the IGC Code safety requirements.

3. On each LNG cargo tank two relief valves are fitted. Identify the correct combination of "set pressure" (lifting pressure) and "reseating pressure" for these valves.

A. 250 mbar and 220 mbar
B. 50 mbar and 20 mbar
C. 2.5 bar and 2.2 bar
D. 500 mbar and 200 mbar

Answer: A — 250 mbar and 220 mbar

The correct answer is 250 mbar and 220 mbar. This complies with established gas tanker operational standards, thermodynamics, and the IGC Code safety requirements.

4. Advantages of reliquefaction plant on LNG tankships will not include,

A. Total quantity of LNG loaded can be delivered to the customer
B. Reduction in heel required on ballast voyag
C. Lower S0 and NO emissions
D. Proven technology and easy availability of crew

Answer: C — Lower S0 and NO emissions

The correct answer is Lower S0 and NO emissions. This complies with established gas tanker operational standards, thermodynamics, and the IGC Code safety requirements.

5. What happens to the air leaving drying tower if the activated alumina inside cylindrical alumina inside cylindrical tank is "old" (inefficient)?

A. It will not be at required dew point
B. It will not be affected at all
C. It will not be warm enough
D. It will not be cold enough

Answer: A — It will not be at required dew point

The correct answer is It will not be at required dew point. This complies with established gas tanker operational standards, thermodynamics, and the IGC Code safety requirements.

6. What is provided to ensure that the low duty gas compressor flow rate does not fall below the designed minimum?

A. An automatic shut down system
B. An automatic surge control system
C. An automatic venting system
D. An automatic start system

Answer: B — An automatic surge control system

A nitrogen seal gas system is fitted on LNG boil-off gas compressors to prevent lubricating oil mist from contaminating the compressed vapor and prevent gas leakage along shaft seals.

7. Onboard an LNG Tanker, while vaporizing during cargo discharge using the main vaporizer, what is the approximate desired outlet temperature of LNG vapour?

A. -140°C
B. -130°C
C. -10°C
D. -120°C

Answer: C — -10°C

The correct answer is -10°C. This complies with established gas tanker operational standards, thermodynamics, and the IGC Code safety requirements.

8. There are typically two types of gas heaters onboard an LNG tanker. One is the main heater and which of the following options is the other?

A. IG heater
B. Fuel gas heater (Boil - off gas heater)
C. Nitrogen heater
D. Air heater

Answer: B — Fuel gas heater (Boil - off gas heater)

The correct answer is Fuel gas heater (Boil - off gas heater). This complies with established gas tanker operational standards, thermodynamics, and the IGC Code safety requirements.

9. A typical membrane method Nitrogen Generator's Air Compressor will trip when the following occur, EXCEPT

A. Nitrogen storage tank pressuree high
B. Air Compressor oil separator pressuree high
C. Air Compressor oil separator inlet temperature high
D. Air Compressor oxygen reading 20% by volum

Answer: D — Air Compressor oxygen reading 20% by volum

In Gaztransport & Technigaz NO 96 membrane containment systems, Invar membranes and perlite insulation boxes maintain cargo containment and thermal insulation.

10. The following are the communication connection integrated in the ESDS fibre optic system, EXCEPT:

A. 1 connection satellite telephon
B. 1 hotline telephone (to terminal)
C. 1 public telephon
D. 1 normal telephone (to terminal)

Answer: A — 1 connection satellite telephon

ESDS automatic fusible thermal elements are designed to melt between 98°C and 104°C during a fire, depressurizing the pneumatic loop and tripping the emergency shutdown system.

11. What is the purpose of having a level gauging system?

A. To avoid over pressureizing of cargo tanks during loading operation
B. To ensure tank cool down rate is maintained at required rat
C. To get accurate tank levels for custody transfer and topping up
D. To prevent sudden temperature change in the insulation spaces

Answer: C — To get accurate tank levels for custody transfer and topping up

The correct answer is To get accurate tank levels for custody transfer and topping up. This complies with established gas tanker operational standards, thermodynamics, and the IGC Code safety requirements.

12. What is the type of gas detection system fitted for spaces with air?

A. Spot metering type fixed inside the individual insulation spaces
B. Infrared type using sequential measurement
C. Portable gas detection system due to mobility of this method
D. Catalytic combustion typ

Answer: A — Spot metering type fixed inside the individual insulation spaces

The correct answer is Spot metering type fixed inside the individual insulation spaces. This complies with established gas tanker operational standards, thermodynamics, and the IGC Code safety requirements.

13. What is the "ESDS" abbreviation stands for?

A. Emergency shutdown deck system
B. Emergency system deck serial
C. Emergency shutdown system
D. Emergency downtime system

Answer: C — Emergency shutdown system

ESDS automatic fusible thermal elements are designed to melt between 98°C and 104°C during a fire, depressurizing the pneumatic loop and tripping the emergency shutdown system.

14. How many suitable and operational portable gas detection equipment shall be available onboard?

A. At least two sets with methane gas detection capability
B. At least one with methane and one of carbon monoxides gas detection capability
C. At least one with methane gas and one of Ammonia gas detection capability
D. At least one with methane gas and one of propane gas detection capability

Answer: A — At least two sets with methane gas detection capability

The correct answer is At least two sets with methane gas detection capability. This complies with established gas tanker operational standards, thermodynamics, and the IGC Code safety requirements.

15. What is the type of gas detection system fitted to monitor gas content of the insulation spaces?

A. Continuous measurement system using catalytic combustion typ
B. Infrared type / sequential measurement
C. Portable gas detection system due to mobility of this method
D. Spot metering type fixed inside the individual insulation spaces

Answer: B — Infrared type / sequential measurement

The correct answer is Infrared type / sequential measurement. This complies with established gas tanker operational standards, thermodynamics, and the IGC Code safety requirements.

16. What is the use of a Distributed Control System (DCS) onboard an LNG carrier?

A. To allow the shore to control the ship's system from the terminal cargo control room
B. To monitor and control main propulsion and cargo operations
C. To monitor and control various cargo equipment distributed on the deck
D. To monitor and control the shore valves from the ship's carao control room

Answer: B — To monitor and control main propulsion and cargo operations

The correct answer is To monitor and control main propulsion and cargo operations. This complies with established gas tanker operational standards, thermodynamics, and the IGC Code safety requirements.

17. Which of the following is not a sign of an LNG gas (vapor) leak into insulation spaces?

A. Comparing to normal trends - high temperature variations on barrier spaces
B. Increase of pressuree in insulation spaces
C. Icing of sea water outside hull when ship at anchor
D. Sudden rise in percentage of methane vapour in insulation spaces

Answer: C — Icing of sea water outside hull when ship at anchor

The correct answer is Icing of sea water outside hull when ship at anchor. This complies with established gas tanker operational standards, thermodynamics, and the IGC Code safety requirements.

18. How is intrinsic safety achieved for electrical circuits used in hazardous areas?

A. By limiting the ignition energy and surface temperature that can arise during operation
B. By increasing mechanical ventilation to the area
C. By limiting the number of equipment used in a spac
D. By installing machinery which have higher power and thus shorter operation tim

Answer: A — By limiting the ignition energy and surface temperature that can arise during operation

The correct answer is By limiting the ignition energy and surface temperature that can arise during operation. This complies with established gas tanker operational standards, thermodynamics, and the IGC Code safety requirements.

19. Why is the 'maximum surface temperature' identified, for electrical equipment used in hazardous areas onboard LNG carriers?

A. The limit is on minimum surface temperature on LNG carriers as the cargo is cryogenic
B. Equipment should operate within these limits to prevent the formation of a hot surfac
C. Equipment should operate within these limits to reduce the power and boil-off consumption
D. Equipment should operate within these limits to reduce the heat transfer to the cryogenic cargo

Answer: B — Equipment should operate within these limits to prevent the formation of a hot surfac

The correct answer is Equipment should operate within these limits to prevent the formation of a hot surfac. This complies with established gas tanker operational standards, thermodynamics, and the IGC Code safety requirements.

20. What can major failure of primary membrane lead to?

A. Flooding of primary insulation space by cargo
B. Increase of temperature in pirmary spaces
C. Decrease of gas content in the primary space readings
D. Increase of gas content in secondary spac

Answer: A — Flooding of primary insulation space by cargo

In Gaztransport & Technigaz NO 96 membrane containment systems, Invar membranes and perlite insulation boxes maintain cargo containment and thermal insulation.

21. How will you measure methane concentration inside insulation spaces?

A. By using hydrocarbon meter
B. By using hydrometer
C. By using personnel oxygen meter
D. By using tank scop

Answer: A — By using hydrocarbon meter

The correct answer is By using hydrocarbon meter. This complies with established gas tanker operational standards, thermodynamics, and the IGC Code safety requirements.

22. For the LNG NO 96 containment system, why is the cargo tanks secondary insulation spaces pressure maintained slightly higher than primary insulation spaces?

A. To avoid vapor transfer into secondary insulation spaces if primary insulation spaces vapor leaks
B. To avoid cold spot formation in inner hull
C. To reduce heat transfer and increase efficiency of insulation spaces
D. To prevent ingress of air through the leak spot into cargo tank

Answer: A — To avoid vapor transfer into secondary insulation spaces if primary insulation spaces vapor leaks

In Gaztransport & Technigaz NO 96 membrane containment systems, Invar membranes and perlite insulation boxes maintain cargo containment and thermal insulation.

23. How do you remove water from the secondary insulation space?

A. By using emergency turbine driven pump fitted in secondary insulation spaces well
B. By using vacuum pump fitted inside compressor room
C. By using emergency cargo pump fitted in affected tank emergency cargo pump column
D. By using emergency hand driven pump fitted in primary insulation spaces well

Answer: A — By using emergency turbine driven pump fitted in secondary insulation spaces well

The correct answer is By using emergency turbine driven pump fitted in secondary insulation spaces well. This complies with established gas tanker operational standards, thermodynamics, and the IGC Code safety requirements.

24. If insulation damage occurs, how does filling the ballast tanks with sea water help in maintaining the hull steel temperature?

A. Through slow heat transfer, as sea water conducts heat better than air
B. Through better heat transfer, as sea water conducts heat better than air
C. Due to the improved heat transfer to outside sea at ambient temperatur
D. As sea water temperature is much lower than LNG temperature, thus helping the heat transfer

Answer: B — Through better heat transfer, as sea water conducts heat better than air

The correct answer is Through better heat transfer, as sea water conducts heat better than air. This complies with established gas tanker operational standards, thermodynamics, and the IGC Code safety requirements.

25. Onboard an LNG tanker with NO 96 containment system, what will happen if a minor membrane leak (crack) occurs above the cargo level?

A. Small flow of liquid into the crack will vaporize. cargo tank pressuree will remain the same.
B. Direct vapor flow rate into the insulation spaces via the crack changes with cargo tank's pressure
C. Cargo pressuree will be tremendously increased boil-off Gas will be out of control
D. Leak will become bigger and primary membranee will collapse inwards

Answer: B — Direct vapor flow rate into the insulation spaces via the crack changes with cargo tank's pressure

In Gaztransport & Technigaz NO 96 membrane containment systems, Invar membranes and perlite insulation boxes maintain cargo containment and thermal insulation.

26. International Certificate of fitness for Carriage of Liquefied Gas in bulk will not include,

A. signify that a minimum standard of constructional safety has been incorporated into the ship's build
B. list the cargo grades that the ship is certified to carry
C. the carriage condition or minimum tank temperature that must be maintained
D. the carriage condition for minimum certificated crew that must be maintained.

Answer: D — the carriage condition for minimum certificated crew that must be maintained.

The correct answer is the carriage condition for minimum certificated crew that must be maintained.. This complies with established gas tanker operational standards, thermodynamics, and the IGC Code safety requirements.

27. Which code will you refer to for the requirements on LNG containment system?

A. SIGTTO
B. IGC Cod
C. IBC Cod
D. OCIMF

Answer: B — IGC Cod

The correct answer is IGC Cod. This complies with established gas tanker operational standards, thermodynamics, and the IGC Code safety requirements.

28. What is the ideal location for the cargo tank from the bottom shell plating, for any Gas Tanker type?

A. B/ 10 or 1.5 meters (4.9 feet), whichever is less
B. B/5 or 3.0 meters (9.8 feet), whichever is less
C. B/ 15 or 2 meters (6.5 feet), whichever isless
D. B/ 4 or 2.4 meters (7.9 feet), whichever is less

Answer: C — B/ 15 or 2 meters (6.5 feet), whichever isless

The correct answer is B/ 15 or 2 meters (6.5 feet), whichever isless. This complies with established gas tanker operational standards, thermodynamics, and the IGC Code safety requirements.

29. As per Chapter 11 of IGC code (fire protection and fire extinction) which of the following is a requirement for an LNG tanker?

A. Firemen's outfits
B. Fire ESD system
C. Fire emergency response plans
D. Fire equipment test / drill

Answer: A — Firemen's outfits

Fixed water spray systems on gas carriers provide boundary cooling for cargo tank domes, deck piping, manifolds, and accommodation forward bulkheads.

30. Onboard an LNG carrier, what provisions are made for separation between the deck and electric motors room?

A. Watertight doors
B. Airlocks
C. Air intakes
D. Weathertight doors

Answer: B — Airlocks

The correct answer is Airlocks. This complies with established gas tanker operational standards, thermodynamics, and the IGC Code safety requirements.

Set 7 — 30 GASCO exit exam questions with answers

1. In an LNG carrier mixtures of methane and air are avoided at all times. What is the reason?

A. Dilution of cargo
B. Risk of fire or explosion
C. Degradation of cargo quality
D. Ice formation in cargo

Answer: B — Risk of fire or explosion

Methane-air mixtures within the flammable range (5% to 15% methane by volume) pose severe risks of fire and explosion, so tanks are inerted with inert gas or nitrogen before introducing air or cargo.

2. Which flammability diagram is used to observe change in cargo tank atmosphere for an LNG gas carrier?

A. Methane and nitrogen mixtures
B. Methane and oxygen mixtures
C. Methane and air mixtures
D. Methane, oxygen and nitrogen mixtures

Answer: D — Methane, oxygen and nitrogen mixtures

The correct answer is Methane, oxygen and nitrogen mixtures. This complies with established gas tanker operational standards, thermodynamics, and the IGC Code safety requirements.

3. What is the maximum interval of time between sampling and analyzing for each sampling head location sequentially?

A. Not exceeding 50 minutes interval
B. Not exceeding 30 minutes interval
C. Not exceeding 40 minutes interval
D. Not exceeding 60 minutes interval

Answer: B — Not exceeding 30 minutes interval

The correct answer is Not exceeding 30 minutes interval. This complies with established gas tanker operational standards, thermodynamics, and the IGC Code safety requirements.

4. How can a gas be liquefied?

A. By mixing gases of higher specific density
B. By the application of pressuree or by cooling
C. By fusion in a closed chamber
D. By evaporation in a closed chamber

Answer: B — By the application of pressuree or by cooling

The correct answer is By the application of pressuree or by cooling. This complies with established gas tanker operational standards, thermodynamics, and the IGC Code safety requirements.

5. What is the IGC code definition for a liquefied gas?

A. Product having a saturated vapor pressuree of 2.8 bar absolute at 37.8°C/100°F
B. Product having a saturated vapor pressuree of 1.76 bar absolute at 37.8°C/ 100 ° F
C. Product having a saturated vapor pressuree of 1.76 bar absolute at 38.7°C/1029 F
D. Product having a saturated vapor pressuree of 2.8 bar absolute at 38.7°C/102° F

Answer: A — Product having a saturated vapor pressuree of 2.8 bar absolute at 37.8°C/100°F

The correct answer is Product having a saturated vapor pressuree of 2.8 bar absolute at 37.8°C/100°F. This complies with established gas tanker operational standards, thermodynamics, and the IGC Code safety requirements.

6. During heat transfer from one body to another, what transfer takes place?

A. Molecul
B. Energy
C. Power
D. Electron

Answer: B — Energy

The correct answer is Energy. This complies with established gas tanker operational standards, thermodynamics, and the IGC Code safety requirements.

7. Why is adequate heel retained during short ballast voyages?

A. It is done as cargo tanks cannot be stripped completely
B. It reduces the ballast to be taken and thus improves turn around
C. It reduces boil-off rates during the ballast voyag
D. It enables loading without further cool down on arrival

Answer: D — It enables loading without further cool down on arrival

Retaining a small heel of LNG cargo on ballast voyages maintains tank cryogenic temperatures, minimizes thermal shock, and avoids lengthy pre-cooling at the loading port.

8. Identify the industry body which is associated with LNG industry although its major stakeholders are from the oil industry?

A. The Oil Companies International Marine Forum (OCIMF)
B. The Oil Charterers International Marine Forum (OCIMF)
C. The Oil & Gas Terminals International Marine Forum (OTIMF)
D. The Oil Terminals International Marine Forum (OTIMF)

Answer: A — The Oil Companies International Marine Forum (OCIMF)

The correct answer is The Oil Companies International Marine Forum (OCIMF). This complies with established gas tanker operational standards, thermodynamics, and the IGC Code safety requirements.

9. Who are the stakeholders represented by the Society of International Gas Tanker & Terminal Operators Ltd (SIGTTO)?

A. Liquefied gas importing countries
B. Liquefied gas shipping and terminals
C. Liquefied gas exporting countries
D. Liquefied gas pipeline owners

Answer: B — Liquefied gas shipping and terminals

SIGTTO (Society of International Gas Tanker and Terminal Operators) represents liquefied gas tanker operators, terminal owners, and industry stakeholders worldwide.

10. Which is the typical temperature trend that indicates a membrane failure?

A. No change in insulation spaces temperature of affected cargo tanks
B. Increase in affected cargo tanks' temperatur
C. Decrease in affected cargo tank's temperatur
D. A decrease in secondary spaces temperature of affected cargo tanks

Answer: D — A decrease in secondary spaces temperature of affected cargo tanks

In Gaztransport & Technigaz NO 96 membrane containment systems, Invar membranes and perlite insulation boxes maintain cargo containment and thermal insulation.

11. What is the use of thermocouples fitted at the surface of the inner hull?

A. To monitor cargo tank temperatur
B. To monitor the inner steel temperatur
C. To monitor hull stresses
D. To monitor inner hull paint thickness

Answer: B — To monitor the inner steel temperatur

The correct answer is To monitor the inner steel temperatur. This complies with established gas tanker operational standards, thermodynamics, and the IGC Code safety requirements.

12. What shall be followed upon after a major LNG spill?

A. Nothing to be done to any affected areas
B. All the affected areas shall be sealed off untll next dry dock repairs
C. All the affected areas shall be wash with oil remover
D. All affected areas shall be thoroughly inspected for any signs of cold shock fractures

Answer: D — All affected areas shall be thoroughly inspected for any signs of cold shock fractures

The correct answer is All affected areas shall be thoroughly inspected for any signs of cold shock fractures. This complies with established gas tanker operational standards, thermodynamics, and the IGC Code safety requirements.

13. What can lead to LNG (cargo) leak into primary insulation spaces?

A. Fatigue crack on ship hull
B. Fatigue cracks on primary membrane
C. Fatigue cracks on secondary membrane
D. Fatigue crack on ballast tank stiffener

Answer: B — Fatigue cracks on primary membrane

The correct answer is Fatigue cracks on primary membrane. This complies with established gas tanker operational standards, thermodynamics, and the IGC Code safety requirements.

14. The LNG cargo tank insulation system is designed to perform the following, EXCEPT:-

A. Maintain the boil - off losses from the cargo at an acceptable level
B. Protect cargo valves and piping
C. Protect the inner hull steel from the effect of excessively low temperatur
D. Reduce heat transfer from the outside into cargo tank

Answer: B — Protect cargo valves and piping

The correct answer is Protect cargo valves and piping. This complies with established gas tanker operational standards, thermodynamics, and the IGC Code safety requirements.

15. Where is the secondary insulation pump well typically located?

A. Aft of each tank secondary insulation spac
B. Forward of each tank secondary insulation spac
C. Centre of each tank secondary insulation spac
D. Top of each tank secondary insulation spac

Answer: A — Aft of each tank secondary insulation spac

The correct answer is Aft of each tank secondary insulation spac. This complies with established gas tanker operational standards, thermodynamics, and the IGC Code safety requirements.

16. Which of the following may not contribute to structural failure of inner hull?

A. Destruction of inner hull due to ship grounding
B. Destruction of ship side due to collision
C. Destruction of Ballast pump during high speed operation
D. Destruction of the insulation space due to sloshing effect

Answer: C — Destruction of Ballast pump during high speed operation

The correct answer is Destruction of Ballast pump during high speed operation. This complies with established gas tanker operational standards, thermodynamics, and the IGC Code safety requirements.

17. During a cargo handling operation which of the following precautions need not be observed to deal with spillage?

A. Fire fighting equipment on standby mod
B. Manifold shipside water spray curtain used
C. Ship cordoned off with LNG containment boom
D. Deck fire main on standby mod

Answer: C — Ship cordoned off with LNG containment boom

The correct answer is Ship cordoned off with LNG containment boom. This complies with established gas tanker operational standards, thermodynamics, and the IGC Code safety requirements.

18. On an LNG tanker, why ballasting operation is carried out concurrently with LNG discharging operation?

A. To ensure stability criteria is met at all times
B. To ensure vessel has sufficient trim for discharging
C. To ensure easy shore gangway adjustment
D. To maintain manifold alignment with shore marker

Answer: A — To ensure stability criteria is met at all times

The correct answer is To ensure stability criteria is met at all times. This complies with established gas tanker operational standards, thermodynamics, and the IGC Code safety requirements.

19. What will happen if cold LNG Boil - Off Gas (BOG) vented through the mast riser?

A. Mast riser will frozen up and it is possible to crack
B. Methane vapor will caught fire immediately
C. Methane vapor will be tuming back to LNG liquid
D. Big white plume will be produced

Answer: D — Big white plume will be produced

The correct answer is Big white plume will be produced. This complies with established gas tanker operational standards, thermodynamics, and the IGC Code safety requirements.

20. Traces of inert gas constituents may be present even after aerating. What are the limits for carbon dioxide (CO2) and carbon monoxide?

A. CO2 <1.5% BV and CO <150ppm
B. CO2 <1.5% BV and CO <250ppm
C. CO2 <1.0%BV and CO <50ppm
D. CO2 <0.5% BV and CO <50ppm

Answer: D — CO2 <0.5% BV and CO <50ppm

The correct answer is CO2 <0.5% BV and CO <50ppm. This complies with established gas tanker operational standards, thermodynamics, and the IGC Code safety requirements.

21. What should be done before commencing unloading test?

A. Ship should provide specifications to port
B. Exchange of ship - shore safety plan
C. Terminal should provide specifications to port
D. Ship and terminal should test the ship's pumps

Answer: B — Exchange of ship - shore safety plan

The correct answer is Exchange of ship - shore safety plan. This complies with established gas tanker operational standards, thermodynamics, and the IGC Code safety requirements.

22. During a long ballast passage which method of retaining heel onboard produces less boil-off?

A. Heel is retained in a center tank and sprayed in others
B. Heel is retained in alternate tanks
C. Heel is retained in 50% of the tanks
D. Adequate heel is retained in all the tanks

Answer: D — Adequate heel is retained in all the tanks

Retaining a small heel of LNG cargo on ballast voyages maintains tank cryogenic temperatures, minimizes thermal shock, and avoids lengthy pre-cooling at the loading port.

23. How do you maintain the cargo tank pressure as low as possible (about 20 - 30 mbar gauge) during inerting operation after gas burning is stopped?

A. by continuous venting via vapor dome's safety valves (manually opened)
B. by continuous venting via vacuum pump mast riser
C. by continuous venting via ship's funnel exhaust
D. by continuous venting via dedicated mast riser

Answer: D — by continuous venting via dedicated mast riser

The correct answer is by continuous venting via dedicated mast riser. This complies with established gas tanker operational standards, thermodynamics, and the IGC Code safety requirements.

24. What should be the vessel's trim and list during gauging for custody transfer?

A. Upright and 1 m down by stern
B. Upright and 0.5 m down by stern
C. There are no restrictions trim and list
D. Upright and even keel

Answer: D — Upright and even keel

The correct answer is Upright and even keel. This complies with established gas tanker operational standards, thermodynamics, and the IGC Code safety requirements.

25. Fire fighters can control small LNG fire by using____________.

A. water
B. water mixed with ail
C. high expansion foam
D. dry chemical powder

Answer: D — dry chemical powder

The correct answer is dry chemical powder. This complies with established gas tanker operational standards, thermodynamics, and the IGC Code safety requirements.

26. Smoke detectors are classified into the following:

A. Photoelectric typ
B. Tonization typ
C. Photoelectric type and Ionization typ
D. Ionization type smoke detectors are in machinery spaces

Answer: C — Photoelectric type and Ionization typ

The correct answer is Photoelectric type and Ionization typ. This complies with established gas tanker operational standards, thermodynamics, and the IGC Code safety requirements.

27. Where do the cargo manifold relief lines, the cargo machinery space relief lines and cargo tanks relief lines lead to?

A. They are led to a common riser
B. They are led to gas line to engine room
C. They are led to vapor domes
D. They are led to high duty compressor suction lin

Answer: C — They are led to vapor domes

The correct answer is They are led to vapor domes. This complies with established gas tanker operational standards, thermodynamics, and the IGC Code safety requirements.

28. Onboard an LNG tanker, for both main and forcing steam vaporizers it is important to note the output capacity (the amount of LNG liquid turned into LNG vapor). What does this capacity depend on?

A. Cooling water supplied to the vaporizers
B. Heat supplied to the vaporizers (steam supply)
C. Air supplied to the vaporizers
D. Condensate returned from the vaporizers

Answer: B — Heat supplied to the vaporizers (steam supply)

The correct answer is Heat supplied to the vaporizers (steam supply). This complies with established gas tanker operational standards, thermodynamics, and the IGC Code safety requirements.

29. Relief valves are used on an LNG carrier liquid header. Identify the correct combination of "set pressure" (lifting pressure) and "reseating pressure" for these valves.

A. 100 mbar and 900 mbar
B. 10 bar and 9 bar
C. 15 bar and 10 bar
D. 1000 mbar and 500 mbar

Answer: B — 10 bar and 9 bar

The correct answer is 10 bar and 9 bar. This complies with established gas tanker operational standards, thermodynamics, and the IGC Code safety requirements.

30. When does the need to rig the auxiliary cargo pump arise?

A. When all the cargo pumps (main and stripping pumps) in a particular tank are out of servic
B. When the needs arise to increase flow rate during discharging operation
C. In case of one cargo pump of the particular tanks is out of servic
D. To increase the loading rate of LNG from shore due to shore pumps is out of servic

Answer: A — When all the cargo pumps (main and stripping pumps) in a particular tank are out of servic

The correct answer is When all the cargo pumps (main and stripping pumps) in a particular tank are out of servic. This complies with established gas tanker operational standards, thermodynamics, and the IGC Code safety requirements.

Set 8 — 30 GASCO exit exam questions with answers

1. Identify the odd one. Which of the following is not an important point to be monitored when using a gas heater?

A. Hot or cold phase flow should be established in the correct sequenc
B. Equipment shall always to be operated in manual mod
C. Heaters shall be pressuree tested prior usage or otherwise checked for leaks at regular
D. Instrumentation and associated equipment should be functioning correctly.

Answer: B — Equipment shall always to be operated in manual mod

The correct answer is Equipment shall always to be operated in manual mod. This complies with established gas tanker operational standards, thermodynamics, and the IGC Code safety requirements.

2. Which of the following types LNG carrier propulsion systems will typically have a re-liquefaction plant onboard?

A. Steam turbin
B. Ultra steam turbines
C. Duel - fuel diesel electric (DFDE)
D. Low - speed diesel

Answer: D — Low - speed diesel

The correct answer is Low - speed diesel. This complies with established gas tanker operational standards, thermodynamics, and the IGC Code safety requirements.

3. Onboard a membrane class LNG carrier, when is an auxiliary or emergency cargo pump put into use?

A. Total cargo pumps failur
B. One cargo pump failur
C. Two cargo pumps failur
D. Stripping pumps failur

Answer: A — Total cargo pumps failur

In Gaztransport & Technigaz NO 96 membrane containment systems, Invar membranes and perlite insulation boxes maintain cargo containment and thermal insulation.

4. Which of the following could be a possible cause when the refrigeration compressor "noise" is high?

A. Lubrication oil pressuree high
B. Lubrication oil pressuree low
C. No lubrication oil
D. Compressor suction pressuree low

Answer: B — Lubrication oil pressuree low

The correct answer is Lubrication oil pressuree low. This complies with established gas tanker operational standards, thermodynamics, and the IGC Code safety requirements.

5. When ESDS is activated either automatically or manually the following equipment is shutdown on the ship, EXCEPT:-

A. HD compressors
B. Deck air conditioning unit
C. All main and auxiliary cargo pumps
D. All manifold valves. allowed valv

Answer: B — Deck air conditioning unit

ESDS automatic fusible thermal elements are designed to melt between 98°C and 104°C during a fire, depressurizing the pneumatic loop and tripping the emergency shutdown system.

6. What is the limitation of a combustible gas detector of catalytic combustion type?

A. It cannot be used for measurement in air
B. It cannot be used for measurement in nitrogen
C. It cannot be used for measurement in methan
D. It cannot be used for measurement in oxygen

Answer: B — It cannot be used for measurement in nitrogen

The correct answer is It cannot be used for measurement in nitrogen. This complies with established gas tanker operational standards, thermodynamics, and the IGC Code safety requirements.

7. Following are means of links available onboard to connect ship's ESDS to shore ESDS, EXCEPT:-

A. Pneumatic link
B. Fibre - optical system
C. Bluetooth link
D. Electrical link

Answer: C — Bluetooth link

ESDS automatic fusible thermal elements are designed to melt between 98°C and 104°C during a fire, depressurizing the pneumatic loop and tripping the emergency shutdown system.

8. During a fully loaded passage, cold spots are beyond control. It is confirmed that it is unsafe to delay discharge of cargo from the damaged cargo tank. What is the action to be taken?

A. To jettison the cargo via the emergency discharge connection
B. To discharge all the cargo to nearby ballast tank
C. To transfer cargo of the affected tank to other fully loaded tanks
D. To vent out all the cargo via vapor header mast riser

Answer: A — To jettison the cargo via the emergency discharge connection

The correct answer is To jettison the cargo via the emergency discharge connection. This complies with established gas tanker operational standards, thermodynamics, and the IGC Code safety requirements.

9. A major failure of the primary membrane will allow LNG to flood the primary insulation space. In addition there will be a tendency for the liquid level in the main cargo tank and a space to equalize. Which of the following is this space?

A. The primary insulation space to equaliz
B. The secondary insulation space to equaliz
C. The both insulation space to equaliz
D. The vapor dome space to equaliz

Answer: A — The primary insulation space to equaliz

In Gaztransport & Technigaz NO 96 membrane containment systems, Invar membranes and perlite insulation boxes maintain cargo containment and thermal insulation.

10. Zone definitions does not include,

A. Zone 0: Area in which an explosive gas atmosphere is present continuously or is present for a long period.
B. Zone 1: Area in which an explosive gas atmosphere is likely to occur in normal operation.
C. Zone 2: Area in which an explosive gas atmosphere is not likely to occur in normal operation, and if it does occur is likely to do so only infrequently and will exit for a short period only.
D. Zone 3: Area in which explosion can occur on a LNGF vessel

Answer: D — Zone 3: Area in which explosion can occur on a LNGF vessel

The correct answer is Zone 3: Area in which explosion can occur on a LNGF vessel. This complies with established gas tanker operational standards, thermodynamics, and the IGC Code safety requirements.

11. How is moisture removed from the insulation spaces before a damaged insulation spaces is being repaired?

A. By injecting wet steam into secondary insulation spaces
B. By installing water heater inside the ballast tank
C. By installing bags of activated alumina inside the insulation spaces
D. By drying out the insulation spaces with nitrogen gas

Answer: D — By drying out the insulation spaces with nitrogen gas

The correct answer is By drying out the insulation spaces with nitrogen gas. This complies with established gas tanker operational standards, thermodynamics, and the IGC Code safety requirements.

12. Based on the principles of segregation, what would you classify cargo containment system as?

A. Gas dangerous spac
B. Gas dangerous zon
C. Gas safe zon
D. Gas safe spac

Answer: A — Gas dangerous spac

The correct answer is Gas dangerous spac. This complies with established gas tanker operational standards, thermodynamics, and the IGC Code safety requirements.

13. Based on the principles of segregation, what would you classify the deck of an LNG carrier?

A. Gas dangerous spac
B. Gas dangerous zon
C. Gas safe zon
D. Gas safe spac

Answer: D — Gas safe spac

The correct answer is Gas safe spac. This complies with established gas tanker operational standards, thermodynamics, and the IGC Code safety requirements.

14. What is the ideal location for a cargo tank from the shell plating, in any Gas tanker type?

A. less than 760 mm (30 inches) from the shell plating
B. less than 750 mm (29.5 Inches) from the ship sid
C. less than 740 mm (29 inches) from the main deck
D. less than 730 mm (28.7 inches) from the summer draft

Answer: B — less than 750 mm (29.5 Inches) from the ship sid

The correct answer is less than 750 mm (29.5 Inches) from the ship sid. This complies with established gas tanker operational standards, thermodynamics, and the IGC Code safety requirements.

15. Which chapter of the IGC Code refers to the summary of minimum equipment requirements for an LNG carrier?

A. Chapter 18
B. Chapter19
C. Chapter 17
D. Chapter 16

Answer: B — Chapter19

The correct answer is Chapter19. This complies with established gas tanker operational standards, thermodynamics, and the IGC Code safety requirements.

16. Which statements is true in accordance with Chapter 15 of the IGC Code?

A. 95% of the total volume of the tank at reference temperatur
B. 96% of the total volume of the tank at reference temperatur
C. 97% of the total volume of the tank at reference temperatur
D. Cargo tanks onboard should not be filled higher 98% of the total volum

Answer: D — Cargo tanks onboard should not be filled higher 98% of the total volum

The correct answer is Cargo tanks onboard should not be filled higher 98% of the total volum. This complies with established gas tanker operational standards, thermodynamics, and the IGC Code safety requirements.

17. Exposure controls/personal protection in MSDS will not include,

A. OSHA permissible exposure limit (PEL), Threshold Limit Value (TLV), and any other exposure limit used or recommended
B. Appropriate handling controls
C. Appropriate engineering controls
D. Individual protection measures, such as personal protective equipment.

Answer: B — Appropriate handling controls

The correct answer is Appropriate handling controls. This complies with established gas tanker operational standards, thermodynamics, and the IGC Code safety requirements.

18. Which of these is not a possibility if by accident the insulation spaces are over pressurized?

A. Membrane collaps
B. Lifting of insulation safety valves
C. Initiation of emergency shut down
D. Tripping of cargo pump

Answer: D — Tripping of cargo pump

The correct answer is Tripping of cargo pump. This complies with established gas tanker operational standards, thermodynamics, and the IGC Code safety requirements.

19. Fire-fighting measures shown in MSDS will not include,

A. Suitable (and unsuitable) extinguishing media
B. Specific hazards arising from the chemical (e.g., nature of any hazardous combustion products)
C. Training requirement for firefighting and Special protective equipment
D. Special protective equipment and precautions for fire-fighters

Answer: C — Training requirement for firefighting and Special protective equipment

The correct answer is Training requirement for firefighting and Special protective equipment. This complies with established gas tanker operational standards, thermodynamics, and the IGC Code safety requirements.

20. What should be the typical content of oxygen in inert gas produced by an inert gas generator onboard an LNG carrier?

A. 0.5%
B. 12.6%
C. 7.5%
D. 13%

Answer: A — 0.5%

The correct answer is 0.5%. This complies with established gas tanker operational standards, thermodynamics, and the IGC Code safety requirements.

21. If an LNG sale document is marked as Free on Board (FOB), after discharge who is the owner of the "heel' retained onboard?

A. Seller owns the heel and may keep it onboard as he controls the vessel
B. Seller owns the heel and may heel out
C. Buyer owns the heel and may keep it onboard as he controls vessel 6
D. Seller owns the heel and may keep It to mix with the next cargo

Answer: C — Buyer owns the heel and may keep it onboard as he controls vessel 6

Retaining a small heel of LNG cargo on ballast voyages maintains tank cryogenic temperatures, minimizes thermal shock, and avoids lengthy pre-cooling at the loading port.

22. What is the temperature at which gas saturates and the water vapor present begins to condense?

A. Boiling point
B. Condensate point
C. Vapor point
D. Dew point

Answer: D — Dew point

The correct answer is Dew point. This complies with established gas tanker operational standards, thermodynamics, and the IGC Code safety requirements.

23. Identify the correct name for a gas or mixture of gases, containing insufficient oxygen to initiate and support combustion where oxygen content is not greater than 5% by volume.

A. Inert gas
B. Cold gas
C. Anti - fire gas
D. Anti - oxygen gas

Answer: A — Inert gas

The correct answer is Inert gas. This complies with established gas tanker operational standards, thermodynamics, and the IGC Code safety requirements.

24. What is the designed boil-off rate for a typical membrane type LNG carrier?

A. 0.15% of full cargo tank capacity / day
B. 0.05% of full cargo tank capacity / day
C. 0.25% of full cargo tank capacity / day
D. 0.5% of full cargo tank capacity / day

Answer: A — 0.15% of full cargo tank capacity / day

In Gaztransport & Technigaz NO 96 membrane containment systems, Invar membranes and perlite insulation boxes maintain cargo containment and thermal insulation.

25. What is done with Normal Boil - off (NBO) vapour?

A. It is removed to maintain the cargo temperature and pressure
B. It is retained in the tanks as it has no effect
C. It is vented to atmospher
D. It is collected and stored in the buffer tank

Answer: A — It is removed to maintain the cargo temperature and pressure

The correct answer is It is removed to maintain the cargo temperature and pressure. This complies with established gas tanker operational standards, thermodynamics, and the IGC Code safety requirements.

26. Which of these factors is not considered when calculating the heel to be retained onboard?

A. Duration of ballast passage
B. Saturated vapor pressuree of the cargo
C. Weather forecast for the loaded passage
D. Level restriction due to sloshing effect

Answer: B — Saturated vapor pressuree of the cargo

Retaining a small heel of LNG cargo on ballast voyages maintains tank cryogenic temperatures, minimizes thermal shock, and avoids lengthy pre-cooling at the loading port.

27. Onboard a LNG tanker, with NO 96 containment system, what happens to the cargo when a cargo tank suffers a major primary barrier failure?

A. The cargo will flood the primary insulation spac
B. The cargo will flow out to shipsid
C. All the cargo will boil - off immediately
D. The cargo will freeze up

Answer: A — The cargo will flood the primary insulation spac

In Gaztransport & Technigaz NO 96 membrane containment systems, Invar membranes and perlite insulation boxes maintain cargo containment and thermal insulation.

28. During a cargo handling operation which of the following precautions need not be observed to deal with spillage?

A. Deck spray pump (IMO) system on standby mod
B. Protective clothing used
C. Constant patrol of cargo area maintained
D. Shore spill team on standby mod

Answer: D — Shore spill team on standby mod

The correct answer is Shore spill team on standby mod. This complies with established gas tanker operational standards, thermodynamics, and the IGC Code safety requirements.

29. What is the main danger when discharging a damaged cargo tank in a normal manner?

A. Discharging pump will trip due to debris in the tank
B. Discharging time will be shorter due to lesser cargo in the tank
C. Collapse of secondary membranee due to high differential head
D. Collapse of the primary membranee due to high differential head

Answer: D — Collapse of the primary membranee due to high differential head

The correct answer is Collapse of the primary membranee due to high differential head. This complies with established gas tanker operational standards, thermodynamics, and the IGC Code safety requirements.

30. What is the definition for the term "minor failure of membrane?

A. Activation of gas detection equipment for insulation despite of purging with nitrogen
B. Fatigue cracks develop with obvious signs of pressuree rise and the presence of methane vapor
C. Porosity of membranee which allows limited liquid into insulation spaces
D. Minor fatigue cracks, passing liquid into the insulation space and becomes gaseous

Answer: D — Minor fatigue cracks, passing liquid into the insulation space and becomes gaseous

In Gaztransport & Technigaz NO 96 membrane containment systems, Invar membranes and perlite insulation boxes maintain cargo containment and thermal insulation.

Set 9 — 30 GASCO exit exam questions with answers

1. Onboard an LNG carrier, under what circumstances is purging or gassing up with LNG vapor is critical prior to cool down of cargo tanks?

A. If nitrogen has been used for inerting
B. If inert gas has been used for inerting
C. If time available for cool down is very short
D. If shore supply for cool down is not availabl

Answer: B — If inert gas has been used for inerting

The correct answer is If inert gas has been used for inerting. This complies with established gas tanker operational standards, thermodynamics, and the IGC Code safety requirements.

2. In a membrane class LNG tanker, why is the cargo tank pressure increased from 20 mbar g to 150 mbar g at the end of operation?

A. To overcome back pressuree from the vent lin
B. To speed up the inerting process
C. To purge all equipment and pipelines thoroughly
D. To test the tanks prior to aerating

Answer: C — To purge all equipment and pipelines thoroughly

In Gaztransport & Technigaz NO 96 membrane containment systems, Invar membranes and perlite insulation boxes maintain cargo containment and thermal insulation.

3. What is the consequence of ice formation in a cargo tank?

A. Burst in the discharge lin
B. Formation of cold spot in ballast tank
C. Possible damagee to the cargo pump during discharging
D. Icing - up of the discharge pump

Answer: C — Possible damagee to the cargo pump during discharging

The correct answer is Possible damagee to the cargo pump during discharging. This complies with established gas tanker operational standards, thermodynamics, and the IGC Code safety requirements.

4. Onboard a membrane class LNG Tanker, what is the ideal tank pressure to be maintained during the warming up operation?

A. Lowest possible pressuree to have good heat transfer process
B. Equal to atmospheric pressuree to allow for free flow of cargo vapor
C. Any pressuree is acceptabl
D. >150 mbar gauge to give good suction for the HD compressors

Answer: D — >150 mbar gauge to give good suction for the HD compressors

In Gaztransport & Technigaz NO 96 membrane containment systems, Invar membranes and perlite insulation boxes maintain cargo containment and thermal insulation.

5. Or the GT NO 96 containment system, what is the recommended cargo tanks inerting operation completion methane content?

A. 5% by volume of methane or mor
B. Less than 3% volume of methan
C. 7% by volume of methane or mor
D. 9% by volume of methane or mor

Answer: B — Less than 3% volume of methan

In Gaztransport & Technigaz NO 96 membrane containment systems, Invar membranes and perlite insulation boxes maintain cargo containment and thermal insulation.

6. Onboard a membrane class LNG tanker what is the ideal pressure differential to be maintained between the cargo tank and insulation spaces (IS)?

A. IS pressuree < cargo tank pressure
B. IS pressuree > cargo tank pressure
C. IS pressuree = cargo tank pressure
D. IS pressuree = cargo tank pressuree + ibar

Answer: A — IS pressuree < cargo tank pressure

In Gaztransport & Technigaz NO 96 membrane containment systems, Invar membranes and perlite insulation boxes maintain cargo containment and thermal insulation.

7. When using the breathing apparatus, the person is warned of low air volume remaining in his air bottle by the meter needle in the red zone and

A. a whistle sounding off
B. a slight difficulty in breathing
C. the life line being tug 3 times by the outside controller
D. his own judgement of his bottle becoming colder upon emptying

Answer: A — a whistle sounding off

The correct answer is a whistle sounding off. This complies with established gas tanker operational standards, thermodynamics, and the IGC Code safety requirements.

8. What is the parameter which influences the separation of nitrogen in a membrane type generator, which uses hollow fiber membranes to produce nitrogen from air?

A. Cooling rate of nitrogen
B. Warming up rate of nitrogen
C. Permeation rate of nitrogen
D. Freezing rate of nitrogen

Answer: C — Permeation rate of nitrogen

In Gaztransport & Technigaz NO 96 membrane containment systems, Invar membranes and perlite insulation boxes maintain cargo containment and thermal insulation.

9. The steam heaters onboard LNG tankers work based on "heat transfer" principles. It is important to note the gas volume/liquid volume ratio of LNG at -161.5°C', What is the correct ratio?

A. 161:1
B. 632:1
C. 505:1
D. 404:1

Answer: B — 632:1

The correct answer is 632:1. This complies with established gas tanker operational standards, thermodynamics, and the IGC Code safety requirements.

10. Why level gauges fitted onboard LNG carriers are of the "closed" type?

A. It restricts release of liquid or vapor to atmosphere when in us
B. It is cost effectiv
C. It is easy to install
D. It is maintenance -- fr

Answer: A — It restricts release of liquid or vapor to atmosphere when in us

The correct answer is It restricts release of liquid or vapor to atmosphere when in us. This complies with established gas tanker operational standards, thermodynamics, and the IGC Code safety requirements.

11. You are in charge of man - entry into an enclosed space. Which of the following will you check using portable gas detectors?

A. Atmospheric pressure
B. Toxicity
C. Dew point
D. Temperatur

Answer: B — Toxicity

The correct answer is Toxicity. This complies with established gas tanker operational standards, thermodynamics, and the IGC Code safety requirements.

12. Onboard an LNG carrier in port, the wheelhouse is unmanned. What will be the watch station of the duty cargo officer?

A. Engine control room
B. Cargo control room
C. Electrical equipment room
D. Officer's cabin

Answer: B — Cargo control room

Retaining a small heel of LNG cargo on ballast voyages maintains tank cryogenic temperatures, minimizes thermal shock, and avoids lengthy pre-cooling at the loading port.

13. Onboard an LNG tanker, the main cargo pumps are installed at the bottom of the tripod mast located in the after end of cargo tanks, Which factor should be adjusted to maximize discharge rate?

A. Vapor supply capacity
B. Trim
C. List
D. Gas burning capacity

Answer: B — Trim

The correct answer is Trim. This complies with established gas tanker operational standards, thermodynamics, and the IGC Code safety requirements.

14. In ship's ESDS, an automatic electrical system which energizes ESDS due to temperature change of the sensor, fitted at each tank domes and both manifold platforms is known as

A. Automatic fusible elements
B. Automatic push button
C. Infrared gas detection system
D. Automatic heat sensors

Answer: A — Automatic fusible elements

ESDS automatic fusible thermal elements are designed to melt between 98°C and 104°C during a fire, depressurizing the pneumatic loop and tripping the emergency shutdown system.

15. Which of the following will not cause an activation of the ESDS?

A. Differential pressuree between cargo tank and atmosphere - too low
B. Differential pressuree between cargo tank and primary insulation space - too low
C. Differential pressuree between primary and secondary insulation space - too low
D. Manual push button and fusible elements

Answer: C — Differential pressuree between primary and secondary insulation space - too low

ESDS automatic fusible thermal elements are designed to melt between 98°C and 104°C during a fire, depressurizing the pneumatic loop and tripping the emergency shutdown system.

16. Where can electrical equipment classified as exib be used?

A. In Zones 0, 1 and 2
B. In Zones 1 and 2
C. In Zones 0 and 2
D. In Zones 0 and 1

Answer: B — In Zones 1 and 2

The correct answer is In Zones 1 and 2. This complies with established gas tanker operational standards, thermodynamics, and the IGC Code safety requirements.

17. What is the latest propulsion solution introduced to the LNG shipping industry?

A. Steam turbines
B. Duel - Fuel Diesel Electric (DFDE)
C. Low - speed diesel with a BOG reliquefaction plant
D. Gas turbin

Answer: B — Duel - Fuel Diesel Electric (DFDE)

The correct answer is Duel - Fuel Diesel Electric (DFDE). This complies with established gas tanker operational standards, thermodynamics, and the IGC Code safety requirements.

18. Onboard an LNG carrier, with NO 96 containment system, what will happen when pressure inside primary space is equal to cargo tank pressure?

A. Primary barrier strips will be shifted from its original position
B. Primary barrier strips will be pressed hard onto primary insulation box
C. Primary barrier will collapse inward
D. Nothing will happen - no damagee to primary barrier

Answer: D — Nothing will happen - no damagee to primary barrier

In Gaztransport & Technigaz NO 96 membrane containment systems, Invar membranes and perlite insulation boxes maintain cargo containment and thermal insulation.

19. Which are the international bodies that provide regulatory standards for electrical equipment certification?

A. IEEC and CENELEC
B. IEC and CENELEC
C. IEEC and ISO
D. IMO and ISO

Answer: B — IEC and CENELEC

The correct answer is IEC and CENELEC. This complies with established gas tanker operational standards, thermodynamics, and the IGC Code safety requirements.

20. After the removal of bulk water from damaged insulation space, Why is it so important to dry out the spaces until the atmosphere dew point is -40°C or lower

A. As there is a possibility for water being trapped and remaining in the insulation spaces
B. As there is a posisbility of mud collected at the bottom of the insulation spaces
C. To cool down the cargo tanks for immediate loading of cargo
D. To avoid the accumulation of rust dust at the bottom of the insulation spac

Answer: A — As there is a possibility for water being trapped and remaining in the insulation spaces

The correct answer is As there is a possibility for water being trapped and remaining in the insulation spaces. This complies with established gas tanker operational standards, thermodynamics, and the IGC Code safety requirements.

21. The commercially viable propulsion systems for Deepsea LNG tanker ships will not include,

A. Conventional plant with steam turbines and dual fired boilers
B. Bual-Fuel Diesel Electric (DFDE) plant
C. Slow Speed Diesel with a Boil-Off Gas (BOG) Reliquefaction Plant
D. Medium speed Diesel with a BOG Reliquefaction plant

Answer: D — Medium speed Diesel with a BOG Reliquefaction plant

The correct answer is Medium speed Diesel with a BOG Reliquefaction plant. This complies with established gas tanker operational standards, thermodynamics, and the IGC Code safety requirements.

22. What should the Master of an LNG carrier do if the CTS fails?

A. Use the gauging reports of shore receiving tanks.
B. Inform the Company and receivers. Use manual gauging and tank tables
C. Inform the terminal and activate ESD button
D. Suspend cargo operation till CTS is repaired

Answer: C — Inform the terminal and activate ESD button

The correct answer is Inform the terminal and activate ESD button. This complies with established gas tanker operational standards, thermodynamics, and the IGC Code safety requirements.

23. As per IGC Code the "design loads" for a particular cargo containment system, which calculation is a requirement?

A. Crack load
B. Sloshing load
C. Hydrostatic load
D. Damage load

Answer: B — Sloshing load

The correct answer is Sloshing load. This complies with established gas tanker operational standards, thermodynamics, and the IGC Code safety requirements.

24. The carriage of LNG cargo requires a certificate for trading called as___________.

A. International Certificate of Fitness for the Carriage of Liquefied Gases in Bulk
B. International Pollution Prevention Certificate for the Carriage of Noxious Liquid Substances in Bulk (NLS Certificate)
C. The International Code of the Construction and Equipment of Ships Carrying Liquefied Gases in Bulk (IGC Code), has been mandatory under OLAS chapter VII
D. International Certificate of Fitness for the Carriage of Dangerous Chemicals in Bulk

Answer: A — International Certificate of Fitness for the Carriage of Liquefied Gases in Bulk

The correct answer is International Certificate of Fitness for the Carriage of Liquefied Gases in Bulk. This complies with established gas tanker operational standards, thermodynamics, and the IGC Code safety requirements.

25. If an LNG sale document is marked as Delivered Ex Ship (DES), after discharge who is the owner of the 'heel' retained onboard?

A. Heel belongs to the buyer
B. Heel belong to the seller
C. Heel belongs 50% to the buyer and 50% to the seller
D. Heel belongs 75% to the buyer and 25% to the seller

Answer: B — Heel belong to the seller

Retaining a small heel of LNG cargo on ballast voyages maintains tank cryogenic temperatures, minimizes thermal shock, and avoids lengthy pre-cooling at the loading port.

26. At what temperature will methane change from vapour to liquid at atmospheric pressure?

A. -141.5°C
B. -161.5°C
C. -151.5°C
D. -131.5°C

Answer: B — -161.5°C

The correct answer is -161.5°C. This complies with established gas tanker operational standards, thermodynamics, and the IGC Code safety requirements.

27. What is the critical temperature and pressure of methane?

A. -145.5°C and 44.7 bars
B. -82.5°C and 47,4 bars
C. -82.5°C and44.7 bars
D. -161.5°C and 47.4 bars

Answer: C — -82.5°C and44.7 bars

The correct answer is -82.5°C and44.7 bars. This complies with established gas tanker operational standards, thermodynamics, and the IGC Code safety requirements.

28. Typical inert gas consists of approximately 0.5% Oxygen, 15% Carbon dioxide, 0.5% Carbon monoxide, Oxides of nitrogen and Sulphur dioxide. Which gas forms nearly 84% of the Inert gas?

A. Propan
B. Nitrogen
C. Butan
D. Methan

Answer: B — Nitrogen

The correct answer is Nitrogen. This complies with established gas tanker operational standards, thermodynamics, and the IGC Code safety requirements.

29. What are the two main contractual arrangements used in LNG shipping?

A. Delivery Ex - Ship (DES) and Freight On Board (FOB)
B. Delivery Ex - Ship (DES) and Free On Board (FOB)
C. Delivery Ex Shore (DES) and Free On Board (FOB)
D. Delivery On Board (DOB) and Free On Board (FOB)

Answer: B — Delivery Ex - Ship (DES) and Free On Board (FOB)

The correct answer is Delivery Ex - Ship (DES) and Free On Board (FOB). This complies with established gas tanker operational standards, thermodynamics, and the IGC Code safety requirements.

30. Natural and shale gas deposits are not supported by_____________.

A. Conventional and non-associated gas deposits which are called natural gas deposits
B. Natural gas deposits which are much closer to the surface just under the seal
C. Shale gas deposits which are deposits of natural gas found in shale formations.
D. Shale gas deposits which are much less deep than the conventional deposits

Answer: D — Shale gas deposits which are much less deep than the conventional deposits

The correct answer is Shale gas deposits which are much less deep than the conventional deposits. This complies with established gas tanker operational standards, thermodynamics, and the IGC Code safety requirements.

Set 10 — 30 GASCO exit exam questions with answers

1. What is the agreement between the buyer and the end-users called as?

A. Sale and Purchase Agreement(SPA)
B. Delivery Ex-Ship (DES)
C. Gas sale agreement(GSA)
D. Free On Board(FOB)

Answer: C — Gas sale agreement(GSA)

The correct answer is Gas sale agreement(GSA). This complies with established gas tanker operational standards, thermodynamics, and the IGC Code safety requirements.

2. Identify the odd one out. Which of these factors will not increase the boil-off onboard an lng carrier?

A. Detoriation of insulation barriers
B. sloshing in the cargo tanks
C. Rasing of insulation space pressure
D. Long loaded passage

Answer: C — Rasing of insulation space pressure

The correct answer is Rasing of insulation space pressure. This complies with established gas tanker operational standards, thermodynamics, and the IGC Code safety requirements.

3. the methods used for producing inert gas onboard LNG carriers are many, which one method may no longer be used?

A. By stoichiometric combustion in an inert gas combustion
B. flue gas from main boilers
C. Nitrogen by fractional distillation or by pressuree swing absorbtion(PSA)
D. Nitrogen by turning liquid nitrogen from shore to nitrogen gas

Answer: B — flue gas from main boilers

The correct answer is flue gas from main boilers. This complies with established gas tanker operational standards, thermodynamics, and the IGC Code safety requirements.

4. Which law states that the sum of the partial pressures of the constituent gases of a mixture of gases is equal to the total pressure of the gas mixture?

A. Boyle's law
B. Gay Lussac's law
C. Charles's law
D. Dalton's law of partial pressure

Answer: D — Dalton's law of partial pressure

The correct answer is Dalton's law of partial pressure. This complies with established gas tanker operational standards, thermodynamics, and the IGC Code safety requirements.

5. What is the quantity of heat absorbed on vaporization at normal boiling point?

A. Vaporization heat
B. Latent heat
C. Condensation heat
D. lost heat

Answer: B — Latent heat

The correct answer is Latent heat. This complies with established gas tanker operational standards, thermodynamics, and the IGC Code safety requirements.

6. During normal loading/ discharging cycle, how does keeping the tanks cool and ready for loading help?

A. It reduces the thermal stresses on the membrane
B. It increases the ship operation costs
C. It increases thermal stresses on the membrane
D. It reduces boil-off in the ballast passage

Answer: A — It reduces the thermal stresses on the membrane

The correct answer is It reduces the thermal stresses on the membrane. This complies with established gas tanker operational standards, thermodynamics, and the IGC Code safety requirements.

7. Find the correct answer. A vessel certified to carry an NLS(Noxious liquid substances) must comply with

A. OSHA regulations
B. International Pollution Prevention Certificate for the carriage of Noxious liquid substances
C. STCW regulations
D. ILO regulations

Answer: B — International Pollution Prevention Certificate for the carriage of Noxious liquid substances

The correct answer is International Pollution Prevention Certificate for the carriage of Noxious liquid substances. This complies with established gas tanker operational standards, thermodynamics, and the IGC Code safety requirements.

8. Based on the principles of segregation, what would you classify the cargo compressor room?

A. Gas safe spac
B. Gas safe zon
C. Gas dangerous zon
D. Gas dangerous spac

Answer: D — Gas dangerous spac

The correct answer is Gas dangerous spac. This complies with established gas tanker operational standards, thermodynamics, and the IGC Code safety requirements.

9. Which of the following are not the early signs of structural failure of the inner hull?

A. Increasing of Lng level in cargo tanks, by incoming seawater
B. Water detected in secondary insulation spac
C. Further lowering of insulation space temperature sensed by the thermocoupl
D. Maximum methane reading detected by the explosive meter inside insulation spaces

Answer: A — Increasing of Lng level in cargo tanks, by incoming seawater

The correct answer is Increasing of Lng level in cargo tanks, by incoming seawater. This complies with established gas tanker operational standards, thermodynamics, and the IGC Code safety requirements.

10. Insulation materials for use on liquefied gas carriers shall possess the following, except:

A. ability to bear physical loads
B. Ingress of moisture is not possible thereb, loss of insulation performanc
C. ability to withstands mechanical damage
D. reasonably lightweight

Answer: B — Ingress of moisture is not possible thereb, loss of insulation performanc

The correct answer is Ingress of moisture is not possible thereb, loss of insulation performanc. This complies with established gas tanker operational standards, thermodynamics, and the IGC Code safety requirements.

11. How is the formation of cold spots on the inner hull surfaces which is not fitted with thermocouples detected?

A. By using remote ice detection device at any tim
B. frequent inspections of inner hull on ballast passage
C. By using remote lng leak detector any tim
D. frequent inspections of inner hull on loaded passage

Answer: D — frequent inspections of inner hull on loaded passage

The correct answer is frequent inspections of inner hull on loaded passage. This complies with established gas tanker operational standards, thermodynamics, and the IGC Code safety requirements.

12. What will happen if the primary space is at least partially flooded with LNG?

A. No reduction in exhaust flow to atmosphere or increase in the temperature of the secondary spaces
B. Changes in exhaust flow to atmosphere and increase in the temperature of secondary spaces
C. Reduction in exhaust to atmosphere or decrease in the temperature of secondary spaces
D. Pressure insulation will increase and temperature for primary spaces will reduces

Answer: A — No reduction in exhaust flow to atmosphere or increase in the temperature of the secondary spaces

The correct answer is No reduction in exhaust flow to atmosphere or increase in the temperature of the secondary spaces. This complies with established gas tanker operational standards, thermodynamics, and the IGC Code safety requirements.

13. Onboard an LNG tanker with NO 96 containment system, with minor membrane leakage, which of the following it not a recommended remedial action?

A. Check and log gas concentration and temperature on the damageed insulation spaces frequently
B. Ensure at all times secondary space pressuree>damageed primary pressuree +0.5 to 10 bar
C. Alter ship's course and speed to increase pressuree within damageed insulation spaces
D. Check location of crack by using vent cock located on nitrogen supply and exhaust

Answer: C — Alter ship's course and speed to increase pressuree within damageed insulation spaces

In Gaztransport & Technigaz NO 96 membrane containment systems, Invar membranes and perlite insulation boxes maintain cargo containment and thermal insulation.

14. What remedial action should be taken as soon as possible prior discharging cargo from a damaged cargo tank?

A. Fix the equalizer between gas dome and secondary insulation spac
B. Fix the equalizer between gas dome and primary insulation spac
C. Fix the equalizer between primary and secondary spaces
D. Fix the equalizer between gas dome and vacuum lin

Answer: B — Fix the equalizer between gas dome and primary insulation spac

The correct answer is Fix the equalizer between gas dome and primary insulation spac. This complies with established gas tanker operational standards, thermodynamics, and the IGC Code safety requirements.

15. Each equipment on LNG ship will be stamped with Information giving the type of protection. That will not include,

A. Ex d IIb T6 means that the equipment is certified Ex d protected by explosion proof enclosur
B. Ex d protected by explosion proof enclosur
C. IIb gas group
D. 17 temperature class -100°C

Answer: D — 17 temperature class -100°C

The correct answer is 17 temperature class -100°C. This complies with established gas tanker operational standards, thermodynamics, and the IGC Code safety requirements.

16. Onboard a membrane type LNG carrier, why does the primary membrane have a tendency to collapse during discharge of cargo from damaged cargo tank?

A. Due to different material use for cargo tank and primary membrane
B. Due to temperature variations
C. Due to large different liquid level
D. Due to small different liquid level

Answer: C — Due to large different liquid level

In Gaztransport & Technigaz NO 96 membrane containment systems, Invar membranes and perlite insulation boxes maintain cargo containment and thermal insulation.

17. Which of the following machinery is used for power generation onboard an LNG Carrier with a steam turbine plant?

A. A forcing vaporizer
B. A diesel generator
C. A degasification unit
D. A reliquefaction plant

Answer: B — A diesel generator

The correct answer is A diesel generator. This complies with established gas tanker operational standards, thermodynamics, and the IGC Code safety requirements.

18. Onboard an LNG carrier, with NO 96 membrane containment system, what is the indication of failure of the primary membrane and primary insulation space?

A. Temperature drop in secondary space temperature probes
B. Temperature drop in cofferdam space temperature probles
C. Temperature drop in wing ballast tank space temperature probles
D. Temperature drop on main deck temperature probles

Answer: A — Temperature drop in secondary space temperature probes

In Gaztransport & Technigaz NO 96 membrane containment systems, Invar membranes and perlite insulation boxes maintain cargo containment and thermal insulation.

19. How does the gas detection system react to a minor leak of primary barrier spaces?

A. Gas percentage methane content will increase depending on the location and size of the crack
B. Gas percentage oygen content will reduce depending on the location and size of the crack
C. Gas percentage nitrogen content will increase depending on the location and size of the crack
D. Gas percentage methane content will decrease depending on the location and size of the crack

Answer: A — Gas percentage methane content will increase depending on the location and size of the crack

The correct answer is Gas percentage methane content will increase depending on the location and size of the crack. This complies with established gas tanker operational standards, thermodynamics, and the IGC Code safety requirements.

20. Which of the following is not a typical counter measure carried out after a major membrane leak or failure?

A. Isolate primary spaces of affected cargo tanks
B. Stop gas burning in boilers
C. Open primary spare exhaust of affected cargo tanks to vent excess pressure
D. Closely monitor all temperature sensors and gas detection system of the affected cargo tank

Answer: B — Stop gas burning in boilers

In Gaztransport & Technigaz NO 96 membrane containment systems, Invar membranes and perlite insulation boxes maintain cargo containment and thermal insulation.

21. Onboard an LNG tanker with NO 96 containment system what will typically happen if a minor membrane leak(crack) occurs below the cargo level?

A. Big flow of liquid into the crack will rapidly vaporize and cargo will be severely damageed
B. Small flow of liquid into the crack will vaporize cargo tank pressuree will increase tremendously increase tremendously
C. Big flow of liquid into the crack will vaporize and colaps the primary membranee inwards
D. Small flow of liquid into the crack will vaporize, cargo tank will remain the sam

Answer: D — Small flow of liquid into the crack will vaporize, cargo tank will remain the sam

In Gaztransport & Technigaz NO 96 membrane containment systems, Invar membranes and perlite insulation boxes maintain cargo containment and thermal insulation.

22. The grade of steel used for inner hull construction is designed so to withstand

A. The main pressuree can be created by UNG voor in an enclosed spac
B. The minimum temperature due to LMG contact
C. The minimun corrosion effect due to steel-air and seawater contact
D. The maximum explosion force that can be created by LNG vapor in an enclosed spac

Answer: B — The minimum temperature due to LMG contact

The correct answer is The minimum temperature due to LMG contact. This complies with established gas tanker operational standards, thermodynamics, and the IGC Code safety requirements.

23. Identify the odd one. Each main cargo pump electric motor is protected from certain faults. Which of the following is an exception?

A. Delayed start
B. Thermal overload (over current)
C. Undercurrent (no load operation)
D. Imbalance between phases (single-phasing)

Answer: A — Delayed start

The correct answer is Delayed start. This complies with established gas tanker operational standards, thermodynamics, and the IGC Code safety requirements.

24. Why does the cofferdam heating system have two sets of heating coils?

A. One for starboard and one for port
B. One for upper and one for lower
C. One in service and one on standby
D. One for forward part and one for aft part

Answer: C — One in service and one on standby

The correct answer is One in service and one on standby. This complies with established gas tanker operational standards, thermodynamics, and the IGC Code safety requirements.

25. In an LNG carrier two types of cargo pumps are fitted in each cargo tank. Identify them by name.

A. Big cargo and small cargo pumps
B. Emergency and small cargo pumps
C. Main cargo and stripping/spray pumps
D. Emergency and big cargo pumps

Answer: C — Main cargo and stripping/spray pumps

The correct answer is Main cargo and stripping/spray pumps. This complies with established gas tanker operational standards, thermodynamics, and the IGC Code safety requirements.

26. What are the two types ur heating medium which may be used for the typical cofferdam heating system onboard LNG carers?

A. Seawater or R 404a
B. Steam or glycol water
C. Warm air or brin
D. Alcohol solution or seawater

Answer: B — Steam or glycol water

The correct answer is Steam or glycol water. This complies with established gas tanker operational standards, thermodynamics, and the IGC Code safety requirements.

27. Capacitance type gauges are reliable as they have no moving parts. Identify the condition under which they may fall?

A. Presence of nitrogen and methan
B. Presence of water, dirt or rust
C. When the tank is empty
D. When the tank is not full

Answer: B — Presence of water, dirt or rust

The correct answer is Presence of water, dirt or rust. This complies with established gas tanker operational standards, thermodynamics, and the IGC Code safety requirements.

28. IGC Requirements on LNG vessels are stated below that will not include

A. The Gas Codes and classification society rules require every cargo tank to be fitted with at least one squid level gaug
B. The Gas Codes require every cargo tank to be fitted with at least two liquid level gauges
C. Chapter 19 of the 1GC code provides the requirements for gauging systems usiing onboard gas carriers.
D. This information is summarized in Appendix 2 of the same code.

Answer: B — The Gas Codes require every cargo tank to be fitted with at least two liquid level gauges

The correct answer is The Gas Codes require every cargo tank to be fitted with at least two liquid level gauges. This complies with established gas tanker operational standards, thermodynamics, and the IGC Code safety requirements.

29. In ESDS pneumatic link system which equipment is used to sense and monitor the air pressure in the system so that the ESDS will activate if the air pressure in system Fall below set point

A. Pressure regulator
B. Pressure switch
C. Pressure control valv
D. Pressure dumping valv

Answer: B — Pressure switch

ESDS automatic fusible thermal elements are designed to melt between 98°C and 104°C during a fire, depressurizing the pneumatic loop and tripping the emergency shutdown system.

30. Why should the temperature of cofferdam and liquid domes be maintained above +5°C

A. To ensure no heat transfers from seawater through outer hull
B. To equal The Teperatures of the containment system and insulation spaces
C. to ensure space is warm for inner hull inspection
D. If inner full temperature drops to sub-zero temperatures, it can suffer structural damage

Answer: D — If inner full temperature drops to sub-zero temperatures, it can suffer structural damage

The correct answer is If inner full temperature drops to sub-zero temperatures, it can suffer structural damage. This complies with established gas tanker operational standards, thermodynamics, and the IGC Code safety requirements.

Set 11 — 30 GASCO exit exam questions with answers

1. Where are the spray and stripping pumps normally installed onboard an LNG tanker?

A. At the end of cargo pipes in cargo pump room
B. At main deck close to liquid dome fittings
C. Inside cargo tanks at the bottom end of tripod mast
D. At main deck close to vapor dome fittings

Answer: C — Inside cargo tanks at the bottom end of tripod mast

The correct answer is Inside cargo tanks at the bottom end of tripod mast. This complies with established gas tanker operational standards, thermodynamics, and the IGC Code safety requirements.

2. In an Air Dryer Plant in the first stage of drying process the air is cooled to around 5 degree by R 404A refrigeration plant during the second stage what drying agents is used to remove the remaining moisture?

A. Silica gel
B. Activated alumina
C. Perlite
D. Invar powder

Answer: B — Activated alumina

The correct answer is Activated alumina. This complies with established gas tanker operational standards, thermodynamics, and the IGC Code safety requirements.

3. When using the main vaporizer to vaporize liquid nitrogen what should be fitted at the inlet of the vaporizer?

A. A removable bend
B. A gas filter
C. A valv
D. A liquid nitrogen detector

Answer: A — A removable bend

The correct answer is A removable bend. This complies with established gas tanker operational standards, thermodynamics, and the IGC Code safety requirements.

4. During the nitrogen or cooling cycle in a reliquefaction plant, nitrogen is compressed in 3-stage centrifugal compressor. How is the compressor cooled?

A. Water cooling
B. Propane cooling / Butane cooling
C. Butane cooling
D. LNG cooling

Answer: A — Water cooling

The correct answer is Water cooling. This complies with established gas tanker operational standards, thermodynamics, and the IGC Code safety requirements.

5. How should the activated alumina in the drying tank be regenerated after the dry air unit has been in use for sometimes (for about 20 hours) or when the high humidity alarm is given?

A. Shutting down the unit and restart the whole plant
B. Warming up the activated alumina outside the tank
C. Back-flushing hot air through the tank
D. Free flow air through the tank

Answer: C — Back-flushing hot air through the tank

The correct answer is Back-flushing hot air through the tank. This complies with established gas tanker operational standards, thermodynamics, and the IGC Code safety requirements.

6. In the LNG re-liquefaction plant, Identify the factor with which the boil-off gas compressor capacity is adjusted automatically?

A. LNG vapour density
B. LNG heat valu
C. LNG Boll-off Rate(BOR)
D. LNG liquid density

Answer: C — LNG Boll-off Rate(BOR)

The correct answer is LNG Boll-off Rate(BOR). This complies with established gas tanker operational standards, thermodynamics, and the IGC Code safety requirements.

7. How is the LNG boil-off gas removed from the cargo tanks brought to the reliquefaction plant?

A. By boll-off gas expanders
B. By low-duty compressors
C. By forcing vaporizer
D. By force draught fans

Answer: B — By low-duty compressors

The correct answer is By low-duty compressors. This complies with established gas tanker operational standards, thermodynamics, and the IGC Code safety requirements.

8. What is fitted to at the outlet of main and forcing steam vaporizers to ensure a stable output and avoid accumulation of non-vaporized liquid?

A. Demister
B. Spiral wires
C. A re-evaporator
D. Condensate level controller

Answer: C — A re-evaporator

The correct answer is A re-evaporator. This complies with established gas tanker operational standards, thermodynamics, and the IGC Code safety requirements.

9. Normally for an air dryer plant, where possible; "regeneration process must be completed at least two (2) weeks before using the dry air plant. What does this action ensure?

A. Residual heat in the regenerated drier is kept within the plant
B. Residual heat in the generated crier to dissipated
C. Residual heat in the regenerated drier is increased
D. Residual heat in the regenerated drier is not disturbed

Answer: B — Residual heat in the generated crier to dissipated

The correct answer is Residual heat in the generated crier to dissipated. This complies with established gas tanker operational standards, thermodynamics, and the IGC Code safety requirements.

10. Why is necessary to purge the auxiliary cargo pump column before the installation can commence?

A. To reduce the tank pressure
B. to ensure the column is filled to the top with cargo
C. To purge out the liquid (cargo) through bottom valve at ensure the column is inerted
D. To purge the air out through bottom valve and ensure column is inerted

Answer: C — To purge out the liquid (cargo) through bottom valve at ensure the column is inerted

The correct answer is To purge out the liquid (cargo) through bottom valve at ensure the column is inerted. This complies with established gas tanker operational standards, thermodynamics, and the IGC Code safety requirements.

11. LNG tankship submerged cargo pump running procedure will not include,

A. The cargo pumps may be restarted after a failed start, a maximum of 4 times excluding the failed attempt
B. This procedure must be adhered to as heat build-up from the high starting current may not be carried away during stripping operations
C. This may be due to the lack of liquid flow when (and if) the pump does not prime, due to the extremely low level of LNG during stripping operations
D. Up to 30 seconds of operation with dry suction but with fluid in the discharge pipe will not damagee the pump or the motor

Answer: A — The cargo pumps may be restarted after a failed start, a maximum of 4 times excluding the failed attempt

The correct answer is The cargo pumps may be restarted after a failed start, a maximum of 4 times excluding the failed attempt. This complies with established gas tanker operational standards, thermodynamics, and the IGC Code safety requirements.

12. What is an LNG carrier provided with to heat up LNG Vapeur delivered from compressors or vaporizers?

A. Steam heated forcing vaporizers
B. Steam generators
C. Steam heated gas heaters
D. Glycol water heated gas

Answer: C — Steam heated gas heaters

The correct answer is Steam heated gas heaters. This complies with established gas tanker operational standards, thermodynamics, and the IGC Code safety requirements.

13. Of the two critical equipment of a typical membrane method nitrogen generator, one is the heater. Identify the other from option given

A. Methane analyzer
B. Carbon dioxide analyzer
C. Oxygen analyzer
D. Nitrogen analyzer

Answer: C — Oxygen analyzer

In Gaztransport & Technigaz NO 96 membrane containment systems, Invar membranes and perlite insulation boxes maintain cargo containment and thermal insulation.

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

A. Radar tank gaug
B. Nitrogen bubbler gaug
C. float gauges
D. steel tape measurements

Answer: A — Radar tank gaug

The correct answer is Radar tank gaug. This complies with established gas tanker operational standards, thermodynamics, and the IGC Code safety requirements.

15. Liquefied gas carriers are normally loaded or unloaded through__________situated amidships.

A. Cargo pumps
B. Manifolds
C. stripping pumps
D. ESD valves

Answer: B — Manifolds

The correct answer is Manifolds. This complies with established gas tanker operational standards, thermodynamics, and the IGC Code safety requirements.

16. 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.

A. Snip test
B. Meggar test
C. cold test
D. load test

Answer: B — Meggar test

The correct answer is Meggar test. This complies with established gas tanker operational standards, thermodynamics, and the IGC Code safety requirements.

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

A. -70C
B. -40C
C. -60C
D. -50C

Answer: B — -40C

The correct answer is -40C. This complies with established gas tanker operational standards, thermodynamics, and the IGC Code safety requirements.

18. What is the purpose of having a cofferdam heating system?

A. To generate sufficient boil- off to sustain dual fuel firing for the boiler in engine room.
B. To ensure that the cofferdam and liquid domes spaces are at all time kept at +5C when at loaded voyag
C. To increase cargo temperature before arrival at discharge terminal
D. To ensure efficiency of vaporizer operation during the cooling down operation

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

The correct answer is To ensure that the cofferdam and liquid domes spaces are at all time kept at +5C when at loaded voyag. This complies with established gas tanker operational standards, thermodynamics, and the IGC Code safety requirements.

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

A. cargo cycl
B. forced vaporization
C. nitrogen or cooling vaporization
D. auxiliary cycl

Answer: B — forced vaporization

Boil-Off Gas (BOG) is the continuous natural vaporization of cryogenic liquefied gas (like LNG at -161.5°C) caused by ambient heat ingress through the cargo tank insulation.

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

A. opened and burned material removed
B. left closed with ventilation off until all boundaries are cool
C. checked for the proper oxygen level
D. opened and doused with water to prevent reflash

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

The correct answer is left closed with ventilation off until all boundaries are cool. This complies with established gas tanker operational standards, thermodynamics, and the IGC Code safety requirements.

21. which of the following conditions can contribute to accidents ?

A. good housekeeping
B. inspections
C. unsafe conditions
D. intelligent work habits

Answer: C — unsafe conditions

The correct answer is unsafe conditions. This complies with established gas tanker operational standards, thermodynamics, and the IGC Code safety requirements.

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

A. nitrogen
B. chlorin
C. carbon
D. oxygen

Answer: B — chlorin

The correct answer is chlorin. This complies with established gas tanker operational standards, thermodynamics, and the IGC Code safety requirements.

23. what is the typical measuring range for an oxygen analyzer?

A. 10ppm volume oxygen in air
B. 0- 25% volume oxygen in air
C. 0-5% volume oxygen in air
D. 0-100% volume oxygen in air

Answer: B — 0- 25% volume oxygen in air

The correct answer is 0- 25% volume oxygen in air. This complies with established gas tanker operational standards, thermodynamics, and the IGC Code safety requirements.

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

A. Equalize the primary insulation space and vapor dome pressurees of the affected cargo tank
B. Stop filling the affected cargo tank's primary insulations with nitrogen
C. open up the affected cargo tank's primary insulations with inspection
D. Warming up the affected cargo tank immediately

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

In Gaztransport & Technigaz NO 96 membrane containment systems, Invar membranes and perlite insulation boxes maintain cargo containment and thermal insulation.

25. 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?

A. To ensure proper draining of ballast water from ballast tank
B. to increase boil-off of cargo while discharging
C. to ensure maximum discharge of cargo prior to warming up of cargo tanks
D. to maximize boil-off of cargo with by increased exposed surface area

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

The correct answer is to ensure maximum discharge of cargo prior to warming up of cargo tanks. This complies with established gas tanker operational standards, thermodynamics, and the IGC Code safety requirements.

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

A. to reduce vessel turnaround tim
B. to keep the vessel within the required limit of draft, trim, stress and stabilty
C. to ensure that the gangway is safe for use at all times
D. deballasting can be done after 50% loading is complet

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

The correct answer is to keep the vessel within the required limit of draft, trim, stress and stabilty. This complies with established gas tanker operational standards, thermodynamics, and the IGC Code safety requirements.

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

A. 20-22 °C/ hour
B. 10-12 °C/ hour
C. 30-32 °C/ hour
D. 40-42 °C/ hour

Answer: B — 10-12 °C/ hour

The correct answer is 10-12 °C/ hour. This complies with established gas tanker operational standards, thermodynamics, and the IGC Code safety requirements.

28. What is the objective of drying cargo tanks?

A. to warm the cargo tanks prior to inerting
B. to remove methane residual
C. to prevent damagee of cargo equipment
D. to reduce moisture content

Answer: D — to reduce moisture content

The correct answer is to reduce moisture content. This complies with established gas tanker operational standards, thermodynamics, and the IGC Code safety requirements.

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

A. terminal- spary line- main liquid line- tank filling val
B. terminal- manifold crossover- main liquid line- tank filling val
C. terminal- manifold crossover - main vapor line- tank filling val
D. terminal-manifold crossover - main liquid line- spary lin

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

The correct answer is terminal- manifold crossover- main liquid line- tank filling val. This complies with established gas tanker operational standards, thermodynamics, and the IGC Code safety requirements.

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

A. in port when alongside as this is a routine, non-critical operation
B. it can be done anywhere but at sea as shore support is required
C. in sheltered waters where the mixture can be exhausted without danger
D. it is done after entry into the drydock

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

The correct answer is in sheltered waters where the mixture can be exhausted without danger. This complies with established gas tanker operational standards, thermodynamics, and the IGC Code safety requirements.

Set 12 — 21 GASCO exit exam questions with answers

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

A. oxygen in the CO2 can form an explosive mixture with LNG
B. at 60 °C CO2 freex=zes to form a powder which can block line components
C. to increase cargo carrying capacity
D. to prevent corrosive effect of CO2 / lng mixtur

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

The correct answer is at 60 °C CO2 freex=zes to form a powder which can block line components. This complies with established gas tanker operational standards, thermodynamics, and the IGC Code safety requirements.

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

A. pressuree rises due to increase in tank wall temperatur
B. pressuree drops due to fall in tank wall temperatur
C. pressuree is not affected by tank cooldown
D. pressuree rises then drops

Answer: B — pressuree drops due to fall in tank wall temperatur

In Gaztransport & Technigaz NO 96 membrane containment systems, Invar membranes and perlite insulation boxes maintain cargo containment and thermal insulation.

3. 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?

A. fuel gas heaters pipelines
B. insulation space lines
C. hd & ld gas compressors discharge lin
D. vapor and liquid manifolds

Answer: B — insulation space lines

The correct answer is insulation space lines. This complies with established gas tanker operational standards, thermodynamics, and the IGC Code safety requirements.

4. 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?

A. to ensure liquid flow into the forward and aft cargo tanks
B. to increase the pressuree in the cargo tanks before discharging
C. to clean anhy impurities in the pipelines before discharging
D. to purge the vapor which remains at both ends of the liquid header

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

The correct answer is to purge the vapor which remains at both ends of the liquid header. This complies with established gas tanker operational standards, thermodynamics, and the IGC Code safety requirements.

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

A. -80 °C
B. +80 °C
C. +120 °C
D. +20 °C

Answer: B — +80 °C

The correct answer is +80 °C. This complies with established gas tanker operational standards, thermodynamics, and the IGC Code safety requirements.

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

A. to maintain/ control cargo tank pressuree and prevent venting
B. to minimize heavy fuel oil consumption
C. to maintain constant pressuree in the insuation spaces
D. to maximize quantity of boil- off use in boiler

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

The correct answer is to maintain/ control cargo tank pressuree and prevent venting. This complies with established gas tanker operational standards, thermodynamics, and the IGC Code safety requirements.

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

A. 95% of total cargo tank capacity of the vessel
B. 98.5% of total cargo tank capacity of the vessel
C. total capacity available in cargo tank
D. spare available for cargo after reduction of vapour spac

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

The correct answer is 98.5% of total cargo tank capacity of the vessel. This complies with established gas tanker operational standards, thermodynamics, and the IGC Code safety requirements.

8. 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?

A. start ld compressor and return gas to shor
B. start hd compressor and return gas to shor
C. increase the set point of common raiser vent setting
D. shut the vapor manifold valv

Answer: B — start hd compressor and return gas to shor

The correct answer is start hd compressor and return gas to shor. This complies with established gas tanker operational standards, thermodynamics, and the IGC Code safety requirements.

9. How is the cool down of cargo tanks done?

A. lng is introduced through the loading lin
B. lng is sprayed into the tanks via the sprayer rings
C. lng vapor is let in through the vapor dom
D. insulation spaces are cool down with nitrogen

Answer: B — lng is sprayed into the tanks via the sprayer rings

The correct answer is lng is sprayed into the tanks via the sprayer rings. This complies with established gas tanker operational standards, thermodynamics, and the IGC Code safety requirements.

10. What is the normal in service operating pressure difference between the primary and secondary insulation spaces?

A. primary IS pressuree = secondary IS pressure
B. primary IS pressuree > secondary IS pressure
C. secondary IS pressuree = primary IS pressuree +1-2mbar
D. primary IS pressuree = secondary IS pressuree +1-2mbar

Answer: C — secondary IS pressuree = primary IS pressuree +1-2mbar

The correct answer is secondary IS pressuree = primary IS pressuree +1-2mbar. This complies with established gas tanker operational standards, thermodynamics, and the IGC Code safety requirements.

11. For the membrane class LNG carrier, during drying operation what is the recommended differential pressure between primary insulation space and cargo tank?

A. tank pressuree< IS pressuree +10mbar
B. tank pressuree > IS pressuree +10mbar
C. any pressuree can be maintained
D. tank pressuree = IS pressuree +10mbar

Answer: B — tank pressuree > IS pressuree +10mbar

In Gaztransport & Technigaz NO 96 membrane containment systems, Invar membranes and perlite insulation boxes maintain cargo containment and thermal insulation.

12. On an lng tanker, during discharging why should stripping pumps be started at a minimum of 0.5m?

A. to ensure pump tripped at a correct level
B. to avoid difficulty in priming the pumps
C. to ensure sufficient current is available when starting the pump
D. to reduce discharging time in port

Answer: B — to avoid difficulty in priming the pumps

The correct answer is to avoid difficulty in priming the pumps. This complies with established gas tanker operational standards, thermodynamics, and the IGC Code safety requirements.

13. On an lng tanker, during discharging which of the following is not a reason for opening the cargo discharge valve to about 10-20% before starting of cargo pump?

A. to avoid vapor lock "bang" at discharge line curve before the valv
B. to achieve optimum flow rate of the pump
C. to avoid damagee to te cargo discharge valv
D. to avoid low current trip

Answer: B — to achieve optimum flow rate of the pump

The correct answer is to achieve optimum flow rate of the pump. This complies with established gas tanker operational standards, thermodynamics, and the IGC Code safety requirements.

14. Why is energy transfer calculated during lng cargo transfer and not just volume of transfer?

A. lng is sold on the basis of heating valu
B. lng being a gas, volume measured is incorrect
C. lng being a cyrogenic liquid volume measured is incorrect
D. it is only done if receiver demands it

Answer: A — lng is sold on the basis of heating valu

The correct answer is lng is sold on the basis of heating valu. This complies with established gas tanker operational standards, thermodynamics, and the IGC Code safety requirements.

15. Onboard lng carrier, what is the maximum allowable filling limit as per the IMO/ IGC regulation?

A. 98.5%
B. 98.6%
C. 98%
D. 99%

Answer: C — 98%

The correct answer is 98%. This complies with established gas tanker operational standards, thermodynamics, and the IGC Code safety requirements.

16. Onboard a LNG tanker, with NO 96 containment system, which valves are used to maintain the pressure within the primary and secondary insulation spaces?

A. Manifold esd valves
B. nitrogen make up and exhaust control valv
C. discharging valves in liquid dom
D. insulation space relief control valv

Answer: B — nitrogen make up and exhaust control valv

In Gaztransport & Technigaz NO 96 membrane containment systems, Invar membranes and perlite insulation boxes maintain cargo containment and thermal insulation.

17. On an lng tanker, during discharging which of the following is not required to ensure the optimum performance of a main cargo pump?

A. monitor the discharge pressure
B. monitor the load current
C. adhere to its performance curv
D. keep adjusting the low current trip set-point

Answer: D — keep adjusting the low current trip set-point

The correct answer is keep adjusting the low current trip set-point. This complies with established gas tanker operational standards, thermodynamics, and the IGC Code safety requirements.

18. On an lng tanker why do we need to maintain vapor arm connected to shore even after completion of discharging until just before sailing?

A. to increase tank pressuree by getting gas from shor
B. to manage tank pressuree in case of ship gas burning failur
C. to drain remaining liquid to shor
D. to ensure proper sequence before disconnection

Answer: B — to manage tank pressuree in case of ship gas burning failur

The correct answer is to manage tank pressuree in case of ship gas burning failur. This complies with established gas tanker operational standards, thermodynamics, and the IGC Code safety requirements.

19. Onboard a membrane class LNG tanker, what is the typical gas heater outlet temperature control set at, during inerting operation using nitrogen?

A. 0 °C
B. -130 °C
C. -20 °C
D. +20 °C

Answer: C — -20 °C

In Gaztransport & Technigaz NO 96 membrane containment systems, Invar membranes and perlite insulation boxes maintain cargo containment and thermal insulation.

20. On a membrane class LNg tanker upon completion of cargo how is it remaining liquid in the discharging arm drained?

A. By injecting nitrogen from shore to ship trimmed by stern
B. by opening one of thr aft cargo tanks loading valve with ship trimmed by stern
C. by opening drain valve at the manifold connection with ship trimmed by head
D. by opening all discharge valves and drain back into the cargo tanks with ship kept even keel

Answer: B — by opening one of thr aft cargo tanks loading valve with ship trimmed by stern

In Gaztransport & Technigaz NO 96 membrane containment systems, Invar membranes and perlite insulation boxes maintain cargo containment and thermal insulation.

21. For the GT NO 96 containment system what is the recommended cargo tank warming up operation completion temperature?

A. Equal to outside air temperatur
B. Above +30 °C
C. Above +10 °C
D. Above -130 °C

Answer: C — Above +10 °C

In Gaztransport & Technigaz NO 96 membrane containment systems, Invar membranes and perlite insulation boxes maintain cargo containment and thermal insulation.

Printing this? Use your browser's Print (Ctrl/⌘ + P) — the buttons, the search box and the site chrome drop out and the questions run on as plain text, so a set fits a few pages. Filter to one set first if you only want that set on paper.

Practise these GASCO questions as a timed paper GASCO exit exam sets and syllabus All 27 STCW exit exam courses

GASCO exit exam questions and answers

Set 1 — 30 GASCO exit exam questions with answers · as grouped in the bank

Set 2 — 30 GASCO exit exam questions with answers · as grouped in the bank

Set 3 — 30 GASCO exit exam questions with answers · as grouped in the bank

Set 4 — 30 GASCO exit exam questions with answers · as grouped in the bank

Set 5 — 30 GASCO exit exam questions with answers · as grouped in the bank

Set 6 — 30 GASCO exit exam questions with answers · as grouped in the bank

Set 7 — 30 GASCO exit exam questions with answers · as grouped in the bank

Set 8 — 30 GASCO exit exam questions with answers · as grouped in the bank

Set 9 — 30 GASCO exit exam questions with answers · as grouped in the bank

Set 10 — 30 GASCO exit exam questions with answers · as grouped in the bank

Set 11 — 30 GASCO exit exam questions with answers · as grouped in the bank

Set 12 — 21 GASCO exit exam questions with answers · as grouped in the bank

Set 1 — 30 GASCO exit exam questions with answers

Set 2 — 30 GASCO exit exam questions with answers

Set 3 — 30 GASCO exit exam questions with answers

Set 4 — 30 GASCO exit exam questions with answers

Set 5 — 30 GASCO exit exam questions with answers

Set 6 — 30 GASCO exit exam questions with answers

Set 7 — 30 GASCO exit exam questions with answers

Set 8 — 30 GASCO exit exam questions with answers

Set 9 — 30 GASCO exit exam questions with answers

Set 10 — 30 GASCO exit exam questions with answers

Set 11 — 30 GASCO exit exam questions with answers

Set 12 — 21 GASCO exit exam questions with answers