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LGTCO/LGTF exit exam questions and answers — Set 14 — Liquefied Gas Tanker Cargo Operations

Set 14 of the Liquefied Gas Tanker Cargo Operations (LGTCO/LGTF) exit exam bank — 30 of 599 questions, 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.

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Set 14 — 30 LGTCO/LGTF exit exam questions with answers

1. Why is the release of methane from a gas carrier a significant environmental concern?

  • A. Methane forms acid rain
  • B. Methane destroys the ozone layer like CFCs
  • C. Methane is a potent greenhouse gas with a much higher warming effect than carbon dioxide
  • D. Methane is heavier than air and pollutes the sea
Answer: C — Methane is a potent greenhouse gas with a much higher warming effect than carbon dioxide
Methane traps far more heat than carbon dioxide over short and medium time horizons, so venting or slipping methane to atmosphere contributes significantly to climate change; minimising releases is part of pollution prevention.

2. When implementing shipboard spill containment for a small leak of LNG on deck, the liquid should be:

  • A. Allowed to spread over the deck to evaporate
  • B. Collected in buckets and poured into the cargo tank
  • C. Covered with a tarpaulin
  • D. Directed overboard clear of the hull while the water spray protects the steelwork
Answer: D — Directed overboard clear of the hull while the water spray protects the steelwork
Spilled cryogenic liquid must be kept off ordinary steel; it is contained in drip trays or flushed overboard clear of the ship's side with water hoses, while the water curtain and deck water spray warm and protect the hull plating.

3. A person is found collapsed inside a cargo compressor room after a suspected gas leak. The attendant at the entrance should:

  • A. Raise the alarm and wait for the rescue team equipped with breathing apparatus
  • B. Ventilate for 10 minutes and then enter without BA
  • C. Enter immediately without breathing apparatus to pull him out
  • D. Close the door and leave the area
Answer: A — Raise the alarm and wait for the rescue team equipped with breathing apparatus
Many enclosed-space fatalities are would-be rescuers. The attendant must never enter, but raise the alarm so that a properly equipped rescue team with breathing apparatus, rescue harness and lifelines can carry out the rescue.

4. Under SOLAS Chapter III, enclosed space entry and rescue drills must be carried out at least once every:

  • A. Year
  • B. Two months
  • C. Week
  • D. Month
Answer: B — Two months
SOLAS regulation III/19 requires crew members with enclosed space entry or rescue responsibilities to take part in an enclosed space entry and rescue drill at least once every two months.

5. Why should the atmosphere of a cargo tank or hold space be tested at different levels before entry?

  • A. Because regulations require exactly three readings
  • B. To check the temperature profile only
  • C. Because gases of different densities can stratify, leaving pockets of vapour or oxygen deficiency
  • D. Because instruments read differently at each level
Answer: C — Because gases of different densities can stratify, leaving pockets of vapour or oxygen deficiency
Heavy vapours such as propane or butane can collect low down while lighter gases like methane rise; testing at several levels and in remote parts of the space reveals pockets that a single reading would miss.

6. During occupation of an enclosed space on a gas carrier, ventilation should:

  • A. Be stopped once the initial atmosphere test is satisfactory
  • B. Be used only if the oxygen level falls
  • C. Be replaced by inert gas
  • D. Be continued throughout the period of entry
Answer: D — Be continued throughout the period of entry
Ventilation must be maintained while people are inside, since residual vapour may be released from pipes, insulation or sludge, and the work itself may affect the atmosphere; the atmosphere must also be re-tested at intervals.

7. Why should persons entering an enclosed space carry a personal multi-gas detector?

  • A. To continuously monitor the atmosphere in their immediate vicinity and warn them of changes
  • B. To communicate with the bridge
  • C. To record the time of entry
  • D. To replace the need for initial atmosphere testing
Answer: A — To continuously monitor the atmosphere in their immediate vicinity and warn them of changes
Conditions inside a space can change after the initial test; a personal multi-gas monitor gives continuous warning of falling oxygen or rising toxic or flammable gas at the entrant's location so they can leave in time.

8. Before opening a flange on a cargo line for maintenance, the line must be:

  • A. Cooled with liquid cargo
  • B. Isolated, drained, depressurised and purged or gas-freed
  • C. Filled with sea water
  • D. Kept under cargo pressure to detect leaks
Answer: B — Isolated, drained, depressurised and purged or gas-freed
Opening a line that still holds liquid or pressurised vapour can release cargo or cause cold burns; the section must be isolated, drained, depressurised and purged with inert gas or gas-freed and verified before work starts.

9. The purpose of a lock-out/tag-out procedure during maintenance of cargo machinery is to:

  • A. Record spare parts used
  • B. Allow the machinery to run unattended
  • C. Prevent inadvertent starting or energising of equipment while work is in progress
  • D. Speed up the work
Answer: C — Prevent inadvertent starting or energising of equipment while work is in progress
Isolating energy sources, locking the isolators and tagging them with the worker's details prevents anyone from starting a pump, compressor or valve actuator while maintenance is being carried out on it.

10. Hot work in the cargo area of a gas tanker may only be carried out:

  • A. Only during cargo operations
  • B. At the discretion of the person doing the work
  • C. At any time when the ship is at sea
  • D. Under a hot work permit authorised by the Master after gas testing and fire precautions are in place
Answer: D — Under a hot work permit authorised by the Master after gas testing and fire precautions are in place
ISGOTT and company SMS procedures require hot work outside designated areas to be controlled by a hot work permit, issued only after risk assessment, isolation, gas freeing and testing, and with fire-fighting equipment and a fire watch ready.

11. While hot work is in progress in or near the cargo area, gas testing should be:

  • A. Repeated at regular intervals or carried out continuously during the work
  • B. Done only once before work starts
  • C. Done only after work is completed
  • D. Done only if a smell is noticed
Answer: A — Repeated at regular intervals or carried out continuously during the work
Vapour can be released from nearby pipes, residues or adjacent spaces during the job; permits therefore require repeated or continuous monitoring and an immediate stop to work if gas is detected.

12. Why is a fire watch maintained for a period after hot work has been completed?

  • A. To return the tools to the store
  • B. To detect any smouldering material or delayed fire caused by the work
  • C. To ventilate the space
  • D. To complete the paperwork
Answer: B — To detect any smouldering material or delayed fire caused by the work
Heat from welding or cutting can be conducted through steel and ignite material on the far side or smoulder unseen; a fire watch after completion ensures that any delayed fire is detected and extinguished early.

13. Cold work on a tanker is defined as work which:

  • A. Involves cryogenic cargo pipelines only
  • B. Is performed at sub-zero temperatures
  • C. Cannot create a source of ignition
  • D. Is carried out at night
Answer: C — Cannot create a source of ignition
ISGOTT defines cold work as work that cannot create a source of ignition; it is still controlled by procedures and may require a permit, especially where it involves opening cargo-containing systems.

14. Use of non-certified portable electrical equipment in a gas-dangerous zone is:

  • A. Permitted only at night
  • B. Permitted if the equipment is battery powered
  • C. Permitted at any time if the operator is careful
  • D. Not permitted unless the area has been made gas-free and a permit has been issued
Answer: D — Not permitted unless the area has been made gas-free and a permit has been issued
Non-certified electrical equipment can produce sparks or hot surfaces; it may only be used in hazardous areas when the area is confirmed gas-free and isolated from cargo sources and the work is authorised under a permit.

15. Electrical equipment marked 'Ex d' in a hazardous area is of which protection type?

  • A. Flameproof enclosure
  • B. Pressurised
  • C. Intrinsically safe
  • D. Increased safety
Answer: A — Flameproof enclosure
'Ex d' denotes a flameproof enclosure, designed to contain an internal explosion and prevent flame transmission to the surrounding flammable atmosphere; 'Ex i' is intrinsically safe, 'Ex e' increased safety and 'Ex p' pressurised.

16. Electrical equipment marked 'Ex e' is of which protection type?

  • A. Intrinsically safe
  • B. Increased safety
  • C. Flameproof
  • D. Oil-immersed
Answer: B — Increased safety
'Ex e' increased-safety equipment uses additional measures to prevent arcs, sparks or excessive temperatures occurring in normal operation; it differs from flameproof 'Ex d' which contains an internal explosion.

17. In hazardous area classification on gas carriers, a Zone 0 area is one in which:

  • A. Only toxic gases are present
  • B. An explosive atmosphere is not expected to occur at all
  • C. An explosive gas atmosphere is present continuously or for long periods, such as inside cargo tanks
  • D. An explosive atmosphere occurs only in abnormal conditions for short periods
Answer: C — An explosive gas atmosphere is present continuously or for long periods, such as inside cargo tanks
IEC 60092-502, referred to by the IGC Code, classifies the interior of cargo tanks and pipes as Zone 0, where a flammable atmosphere is present continuously or for long periods; only intrinsically safe equipment of the highest category is permitted there.

18. In the ship/shore safety checklist, items marked with the code 'R' must be:

  • A. Reported to the flag State
  • B. Removed from the checklist
  • C. Recorded only once
  • D. Re-checked at intervals agreed between ship and terminal
Answer: D — Re-checked at intervals agreed between ship and terminal
Items coded 'R' are re-checked at intervals agreed between the ship and terminal and stated in the checklist, since conditions such as moorings, communications and gangway safety can change during the operation.

19. The ship/shore safety checklist is completed and signed by:

  • A. The responsible officer of the ship and the terminal representative
  • B. The port State control officer only
  • C. The Master and the Chief Engineer only
  • D. The pilot and the agent
Answer: A — The responsible officer of the ship and the terminal representative
The checklist is a joint declaration completed by the ship's responsible officer and the terminal representative after jointly checking the items, confirming agreed safety measures before and during cargo transfer.

20. If an item in the ship/shore safety checklist cannot be answered affirmatively, then:

  • A. The item is simply left blank
  • B. Cargo operations should not start until the reason is stated and appropriate precautions are agreed between ship and terminal
  • C. The ship must leave the berth immediately
  • D. The terminal decides alone without informing the ship
Answer: B — Cargo operations should not start until the reason is stated and appropriate precautions are agreed between ship and terminal
ISGOTT guidance is that a negative answer must be explained and appropriate precautions agreed and recorded between ship and terminal; operations should not proceed until both parties are satisfied it is safe.

21. Why must moorings be tended continuously during cargo transfer at a gas terminal?

  • A. To reduce boil-off
  • B. To allow the gangway to be removed
  • C. To keep the ship within the operating envelope of the loading arms and avoid ERS activation
  • D. To save fuel
Answer: C — To keep the ship within the operating envelope of the loading arms and avoid ERS activation
Changes in draft and tide cause the ship to move; slack moorings may let the ship drift outside the loading arm envelope, triggering ESD and emergency release or damaging the arms, so moorings are watched and tended throughout.

22. Which of the following spaces on a gas carrier must be treated as an enclosed space?

  • A. The open forecastle deck
  • B. The crew mess room
  • C. The navigation bridge
  • D. The hold space surrounding an independent cargo tank
Answer: D — The hold space surrounding an independent cargo tank
Hold spaces, interbarrier spaces, cargo tanks, cofferdams and similar spaces have limited openings, poor ventilation and may contain inert gas or cargo vapour, so entry is controlled by enclosed space entry procedures and permit.

23. Before personnel enter a hold space that has been inerted with nitrogen, the space must be:

  • A. Thoroughly ventilated with fresh air and tested for oxygen and gas, unless entry is with breathing apparatus under a special procedure
  • B. Kept inerted to prevent fire
  • C. Sprayed with water
  • D. Entered quickly while holding one's breath
Answer: A — Thoroughly ventilated with fresh air and tested for oxygen and gas, unless entry is with breathing apparatus under a special procedure
Nitrogen gives no warning and causes rapid asphyxiation; the space must be ventilated with air and tested to confirm normal oxygen and no cargo vapour, or entry made only with breathing apparatus under strictly controlled procedures.

24. Before hot work is carried out on a section of cargo pipeline, the pipeline must be:

  • A. Cooled with liquid nitrogen
  • B. Isolated, gas-freed and tested to less than 1% LFL
  • C. Filled with cargo vapour to exclude air
  • D. Pressurised with inert gas to 3 bar
Answer: B — Isolated, gas-freed and tested to less than 1% LFL
Hot work on cargo piping requires the section to be isolated from all cargo sources and gas-freed, with tests confirming hydrocarbon content below 1% LFL in and around the work area, as required by ISGOTT hot work procedures.

25. Which of the following is an example of cold work?

  • A. Gas cutting
  • B. Electric arc welding
  • C. Hand painting with a brush
  • D. Grinding with a power tool
Answer: C — Hand painting with a brush
Hand painting with a brush cannot create an ignition source and is classed as cold work; welding, cutting and power grinding produce sparks or hot surfaces and are hot work requiring a hot work permit.

26. Which items are agreed and recorded during the pre-transfer conference and ship/shore safety checklist?

  • A. The ship's next drydock date
  • B. Bunker prices at the next port
  • C. The crew's leave schedules
  • D. Maximum transfer rates, ESD procedures and ship/shore communication methods
Answer: D — Maximum transfer rates, ESD procedures and ship/shore communication methods
The pre-transfer conference and checklist record agreed cargo quantities and rates, maximum pressures, ESD and emergency procedures and communication methods, so ship and shore operate to the same plan.

27. Why should a rescue harness, lifeline and hoisting equipment be ready at the entrance during an enclosed space entry?

  • A. So that a collapsed entrant can be recovered quickly without delay
  • B. For use by the attendant to enter the space
  • C. To measure the depth of the space
  • D. To meet port State paperwork requirements only
Answer: A — So that a collapsed entrant can be recovered quickly without delay
Rescue equipment positioned at the access ready for immediate use allows the rescue team to recover a casualty quickly; delays in fetching equipment greatly reduce the chance of survival in an oxygen-deficient or toxic atmosphere.

28. A surveyor asks you to state the numeric threshold the IGC Code uses to classify a bulk liquid as a 'liquefied gas'. Which figures identify it?

  • A. A vapour pressure exceeding 2.8 bar absolute at 37.8 °C
  • B. A vapour pressure exceeding 1.013 bar absolute at 15 °C
  • C. A boiling point below 0 °C at atmospheric pressure
  • D. A vapour pressure exceeding 2.8 bar gauge at 45 °C
Answer: A — A vapour pressure exceeding 2.8 bar absolute at 37.8 °C
The IGC Code fixes the definition at a vapour pressure exceeding 2.8 bar absolute (0.28 MPa) at 37.8 °C — a substance that would be a gas at ambient conditions and is only liquid because it is pressurised, cooled, or both. Option 3 corrupts it by quoting gauge pressure at a different reference temperature; the true definition is absolute pressure at 37.8 °C.

29. A small ethane vapour leak has warmed to ambient on an open deck. With a relative vapour density of about 1.05 (air = 1), the vapour will:

  • A. Rise clear of the deck because it is lighter than air
  • B. Settle slowly and low, being only marginally heavier than air
  • C. Shoot upward and disperse like warm methane
  • D. Hang as a static ball at head height
Answer: B — Settle slowly and low, being only marginally heavier than air
Ethane vapour at about 1.05 is only just heavier than air, so it settles slowly into low areas rather than lifting. Methane (about 0.55) is genuinely lighter than air once warm — the reason option 2 is wrong — but ethane, propane and butane all sit at or above 1.0 and collect at deck level.

30. Methane's critical temperature is about −82.5 °C. For a cargo officer, what does this single figure establish about carrying LNG at sea temperatures?

  • A. It can be liquefied provided the tank is rated to a high enough pressure
  • B. It stays liquid unaided at atmospheric pressure
  • C. It cannot be liquefied by pressure at all and must be carried refrigerated
  • D. Its vapour pressure falls to zero above that temperature
Answer: C — It cannot be liquefied by pressure at all and must be carried refrigerated
Above its critical temperature no pressure whatever will liquefy a gas, and ambient is roughly 100 °C above methane's −82.5 °C — so LNG can only be held liquid by deep cold. Option 0 is the classic misconception: it is not a question of tank strength, because no pressure works above the critical temperature.

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