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Key Facts: STCW Basic Gas Tanker Exam

Regulation V/1-2

STCW Requirement

STCW Convention and Code

Model Course 1.04

IMO Syllabus Basis

IMO Model Course

-162C

Boiling Point of LNG (methane)

Gas cargo properties

5-15%

Methane Flammable Range in Air

Gas cargo properties

About 3-4 days

Typical Course Length

IMO Model Course 1.04

A-VI/1

Prerequisite Basic Safety Training

STCW Section A-V/1-2

3 months

Alternative Gas Tanker Sea Service

STCW Section A-V/1-2

STCW Basic Training for Liquefied Gas Tanker Cargo Operations (Regulation V/1-2, standard of competence in Table A-V/1-2-1) qualifies seafarers for cargo duties on LNG, LPG, ammonia and ethylene carriers. Built on IMO Model Course 1.04, it runs about 3-4 days and ends in a written, commonly multiple-choice, assessment. Content spans gas physical and chemical properties (boiling points such as methane -162C, propane -42C, ammonia -33C, ethylene -104C; methane flammable range 5-15%; ~600:1 LNG expansion); hazards including cryogenic burns, brittle fracture of carbon steel, asphyxiation, ammonia toxicity, BLEVE and rollover; gas-measuring instruments (oxygen analysers, explosimeters, tankscopes, toxic detectors); safety equipment such as water spray, PPE, inerting, drying, purging and gas-freeing; firefighting with dry chemical powder (water is never applied to cryogenic spills); emergency procedures including ESD; and pollution prevention under the IGC Code and MARPOL. Prerequisite is basic safety training A-VI/1; an alternative is at least three months of approved gas tanker sea service. A certificate of proficiency is issued on passing.

Sample STCW Basic Gas Tanker Practice Questions

Try these sample questions to review concepts for the STCW Basic Gas Tanker exam. Each question includes a detailed explanation. Start the interactive quiz above for the full 100+ question experience with AI tutoring.

1Under which STCW regulation is mandatory basic training for liquefied gas tanker cargo operations specified?
A.Regulation V/1-2
B.Regulation V/1-1
C.Regulation VI/1
D.Regulation V/2
Explanation: STCW Regulation V/1-2 (with the standard of competence in Section A-V/1-2 and Table A-V/1-2-1) governs the mandatory training and qualification of masters, officers and ratings serving on liquefied gas tankers.
2Which prior training is a prerequisite before a seafarer can enrol in basic training for liquefied gas tanker cargo operations?
A.Basic training in safety (A-VI/1)
B.Advanced firefighting (A-VI/3)
C.Ship security officer (A-VI/5)
D.Medical first aid (A-VI/4-1)
Explanation: STCW Section A-V/1-2 requires candidates to have completed basic training in accordance with Section A-VI/1 before undertaking basic gas tanker training.
3Approximately what is the atmospheric-pressure boiling point of LNG (predominantly methane)?
A.-42 degrees Celsius
B.-162 degrees Celsius
C.-104 degrees Celsius
D.-33 degrees Celsius
Explanation: Methane, the main constituent of LNG, boils at approximately -162 degrees Celsius at atmospheric pressure, making LNG a deeply cryogenic cargo.
4What is the approximate atmospheric boiling point of commercial propane carried as LPG?
A.-42 degrees Celsius
B.-162 degrees Celsius
C.0 degrees Celsius
D.-88 degrees Celsius
Explanation: Propane boils at approximately -42 degrees Celsius at atmospheric pressure; it is one of the principal components of LPG along with butane.
5Methane gas is flammable in air over approximately which concentration range by volume?
A.1 to 9 percent
B.12 to 25 percent
C.2 to 10 percent
D.5 to 15 percent
Explanation: The flammable range of methane in air is approximately 5 percent (lower flammable limit) to 15 percent (upper flammable limit) by volume.
6What is the primary hazard of skin contact with a liquefied gas such as LNG at its cargo temperature?
A.Cryogenic burn and frostbite
B.Chemical corrosion of the skin
C.Radioactive contamination
D.Allergic dermatitis
Explanation: Contact with a cryogenic liquid such as LNG instantly freezes living tissue, causing severe cold burns (frostbite) similar in appearance and treatment to thermal burns.
7Why is ordinary carbon steel unsuitable for direct contact with cryogenic liquefied gas, requiring special low-temperature materials?
A.It becomes magnetic and attracts vapour
B.It suffers brittle fracture at low temperature
C.It expands and ruptures fittings
D.It catalyses spontaneous combustion
Explanation: At cryogenic temperatures ordinary carbon (mild) steel loses ductility and becomes brittle, so contact with a cold spill can cause sudden brittle fracture; gas tanks use materials such as nickel steel, stainless steel or aluminium.
8A crew member enters a cargo compartment where methane vapour has displaced air. Even though methane is non-toxic, what is the principal life-threatening hazard?
A.Acute chemical poisoning
B.Heat stress
C.Hydrogen sulphide exposure
D.Asphyxiation from oxygen deficiency
Explanation: Hydrocarbon vapours such as methane are simple asphyxiants: they displace oxygen, so even a non-toxic gas can cause unconsciousness and death by oxygen deficiency in an enclosed space.
9Which liquefied gas cargo is notable for being toxic as well as flammable, requiring particular care for crew respiratory protection?
A.Propane
B.Ammonia
C.Butane
D.Methane
Explanation: Anhydrous ammonia is both toxic and flammable; it is corrosive to eyes and respiratory tract and has a low threshold limit value, so respiratory protection and gas detection are essential.
10What does the abbreviation BLEVE stand for in the context of pressurised liquefied gas hazards?
A.Boiling Liquid Expanding Vapour Explosion
B.Burning Liquid Expanding Vapour Emission
C.Basic Liquid Evaporation Vapour Event
D.Buoyant Layer Expansion Vapour Escape
Explanation: BLEVE means Boiling Liquid Expanding Vapour Explosion - the catastrophic rupture of a vessel containing a pressurised liquefied gas above its atmospheric boiling point, releasing a rapidly expanding, often ignited, vapour cloud.

About the STCW Basic Gas Tanker Exam

Basic Training for Liquefied Gas Tanker Cargo Operations is the mandatory entry-level qualification under STCW Regulation V/1-2 for masters, officers and ratings assigned cargo duties on liquefied gas carriers. The course follows IMO Model Course 1.04 and covers gas properties, hazards, safety equipment, gas-measuring instruments, firefighting, emergency procedures and pollution prevention. It is delivered worldwide by approved training centres over roughly 3-4 days and concludes with a written, commonly multiple-choice, assessment. Candidates must have completed basic safety training (A-VI/1) first; an alternative route is at least three months of approved gas tanker sea service.

Exam sponsor: Flag-state-approved maritime training centres under the STCW Convention. The requirements and fees below concern the certification or admission exam, separate from our free practice resources.

Assessment

Question count not published by the exam provider

Time Limit

End-of-course written assessment, typically 1-2 hours

Passing Score

Pass mark set by the approved training centre (commonly 70%)

Exam / Certification Fees

Varies by training centre (typically several hundred US dollars for the course)

Exam sponsor website

Our practice resources: topics covered

We aim to reflect publicly available exam outlines and topic information in our study resources. Coverage, format, and difficulty may differ from the actual exam, and we cannot guarantee that every detail is accurate or current. Confirm exam requirements, fees, and policies with the official exam sponsor.

20%

Gas Properties & Chemistry

Boiling points (methane -162C, propane -42C, butane ~0C, ammonia -33C, ethylene -104C), vapour density and behaviour of cold versus warm vapour, liquid-to-gas expansion (~600:1 for LNG), pressure-temperature/saturation relationship, flammable range (methane 5-15%), flash point and continuous boil-off

22%

Hazards & Health Effects

Cryogenic cold burns and frostbite first aid, brittle fracture of carbon steel at low temperature, simple asphyxiation by hydrocarbon and nitrogen, ammonia toxicity and threshold limit value, flammability and explosion, BLEVE, tank rollover, electrostatic ignition and liquid expansion of trapped cargo

14%

Gas-Measuring Instruments

Oxygen analysers and the 20.9% safe entry level, catalytic combustible gas indicators (explosimeters) and their failure in oxygen-deficient atmospheres, tankscope/interferometer for inerted tanks, toxic gas detectors and colorimetric tubes, and zeroing/span calibration before use

20%

Safety Equipment & Atmosphere Control

Cryogenic PPE and self-contained breathing apparatus, fixed water spray/drench systems for structure protection and vapour dispersion, inerting with nitrogen, drying and purging, gas-freeing without passing through the flammable range, pressure relief valves, level gauging and overfill alarms

14%

Firefighting & Emergency Procedures

Fixed dry chemical powder systems with monitors and hand lines, why water is never applied to a cryogenic spill, emergency shutdown (ESD) and agreed valve-closing times, gas-leak and gas-fire response, enclosed-space rescue with breathing apparatus, ship/shore safety checklist and drills

10%

Pollution Prevention & Regulation

STCW Regulation V/1-2 and Section A-V/1-2, IGC Code construction and equipment standards, MARPOL pollution prevention, controlled vapour management and reliquefaction versus venting, methane greenhouse impact, certification routes and obligations under applicable laws

Preparing for the STCW Basic Gas Tanker Exam

What You Need to Know

  • Passing score: Pass mark set by the approved training centre (commonly 70%)
  • Assessment: Question count not published by the exam provider
  • Time limit: End-of-course written assessment, typically 1-2 hours
  • Exam / certification fees: Varies by training centre (typically several hundred US dollars for the course) Official sources

Using Our Practice Resources

  • Work through all 100 available questions
  • Review every answer and explanation
  • Track weak areas and revisit them
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STCW Basic Gas Tanker: Suggested Study Strategy

1Memorise the key boiling points: methane (LNG) about -162C, ethylene -104C, propane (LPG) -42C, ammonia -33C and butane about 0C, since carriage temperature and hazards follow from them
2Know the methane flammable range of roughly 5% to 15% by volume and remember that cold methane vapour is heavier than air until it warms, so it drifts low before rising
3Learn that ordinary carbon steel suffers brittle fracture at cryogenic temperatures, which is why gas tanks use nickel steel, stainless steel or aluminium and why drip trays protect the deck
4Understand instrument limits: oxygen analysers confirm the 20.9% safe-entry level, but catalytic explosimeters read falsely low in inerted or oxygen-deficient atmospheres, where a tankscope is used instead
5Remember the firefighting rule: never apply water directly to a cryogenic spill; use water spray to protect structure and disperse vapour, and dry chemical powder to fight the cargo fire
6For ammonia, treat it as toxic and corrosive as well as flammable: use SCBA, knock down vapour with a water curtain (ammonia is highly water-soluble) and flush skin and eyes with copious water

Frequently Asked Questions

What is STCW Basic Training for Liquefied Gas Tanker Cargo Operations?

It is the mandatory entry-level course under STCW Regulation V/1-2 for masters, officers and ratings with cargo duties on liquefied gas carriers. Following IMO Model Course 1.04, it covers gas properties, hazards, safety equipment, gas measuring, firefighting, emergency procedures and pollution prevention.

Is the assessment multiple choice?

Most approved training centres assess basic gas tanker training with a written, commonly multiple-choice, end-of-course test plus practical competence demonstration against Table A-V/1-2-1. The exact format and pass mark (often around 70%) are set by the individual approved centre and flag state.

What are the prerequisites for the course?

Candidates must first complete basic training in safety under STCW Section A-VI/1. The basic gas tanker requirement can alternatively be met by at least three months of approved seagoing service on a liquefied gas tanker, combined with the required standard of competence.

How is this different from the oil and chemical tanker certificate?

Liquefied gas basic training is governed by Regulation V/1-2 and is a separate certificate from the oil and chemical tanker basic training under Regulation V/1-1. Holding one does not cover the other, because the cargoes, hazards and equipment differ significantly.

Which cargoes does the training cover?

It covers the main liquefied gases carried in bulk, including LNG (methane), LPG (propane and butane), ammonia and ethylene. Trainees learn each cargo's boiling point, vapour behaviour, flammability and, for ammonia, its toxicity, so they can apply the correct safety and emergency measures.

Why is water never sprayed directly onto a cryogenic gas spill?

Water is far warmer than the cryogenic liquid, so it boils violently on contact and dramatically increases flammable or toxic vapour generation. Water spray is instead used to cool and protect structures and disperse vapour, while dry chemical powder is used to fight cargo fires.

How long is the course and does the certificate expire?

The basic course is typically delivered over about 3-4 days (around 32 hours) and ends with a written assessment. The certificate of proficiency does not routinely expire, though flag states or companies may require refresher training to keep knowledge current.