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TASCO exit exam questions and answers — Set 8 — Advanced Training for Oil Tanker Cargo Operations

Set 8 of the Advanced Training for Oil Tanker Cargo Operations (TASCO) exit exam bank — 30 of 305 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.

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Set 8 — 30 TASCO exit exam questions with answers

1. What are the units of specific gravity?

  • A. kg/m3
  • B. kgf/m3
  • C. No units
  • D. m3/tonne
Answer: C — No units
Specific gravity is the ratio of the density of a substance to the density of water at a reference temperature. Being a ratio of two densities, it is dimensionless and has no units.

2. When should the ship/shore safety checklist be completed?

  • A. During the operation
  • B. Prior to the operation
  • C. On completion of the operation
  • D. One day before arrival in port
Answer: B — Prior to the operation
ISGOTT requires the ship/shore safety checklist to be completed jointly by the ship and terminal before cargo or ballast operations start, with repetitive checks made at agreed intervals during the operation.

3. On board tankers, in which of the following areas are sources of ignition fully controlled?

  • A. Engine room and accommodation
  • B. Cargo tanks and main deck (cargo area)
  • C. Bridge
  • D. All of the above
Answer: B — Cargo tanks and main deck (cargo area)
Flammable vapour may be present at any time in the cargo tanks and on the cargo deck, so ISGOTT requires sources of ignition to be strictly excluded there, using intrinsically safe equipment and hot work control.

4. In the scrubber tower, water absorbs ____ more readily at lower temperatures.

  • A. SO3
  • B. SO2
  • C. Both SO2 and SO3
  • D. None of the above
Answer: B — SO2
The solubility of sulphur dioxide in sea water increases as the temperature falls, so cooling the flue gas in the scrubber improves SO2 removal. SO3 is removed mainly by reaction and droplet capture.

5. Many petroleum products, especially the more volatile ones, cause

  • A. Dermatitis
  • B. Skin irritation
  • C. Loss of skin
  • D. Both dermatitis and skin irritation
Answer: D — Both dermatitis and skin irritation
Petroleum products, particularly volatile ones, remove natural oils from the skin, causing irritation and on repeated contact dermatitis. ISGOTT advises avoiding skin contact and using protective gloves and clothing.

6. Which instrument is used to determine the colour of petroleum products?

  • A. Saybolt chromometer
  • B. Cleveland apparatus
  • C. Pensky-Martens apparatus
  • D. None of the above
Answer: A — Saybolt chromometer
The Saybolt chromometer (ASTM D156) measures the colour of refined light products such as gasoline, kerosene and jet fuel. The Cleveland and Pensky-Martens apparatus are used for flash point determination.

7. Where only hydrochloric acid is carried, a vapour detection system is to be provided for

  • A. Hydrogen chloride vapour
  • B. Hydrogen sulphide
  • C. Hydrogen peroxide
  • D. None of the above
Answer: A — Hydrogen chloride vapour
Hydrochloric acid gives off hydrogen chloride vapour, which is toxic and corrosive. Where it is the only toxic cargo carried, the vapour detection required by the IBC Code is for hydrogen chloride.

8. Where in each monitored space should the gas detector head be placed on a dedicated oil tanker?

  • A. At the bottom
  • B. At the top
  • C. In the centre (vertically)
  • D. At any point in the space
Answer: A — At the bottom
Petroleum hydrocarbon gases are heavier than air and collect in the lower parts of spaces such as pump rooms, so detector heads are placed near the bottom to detect accumulations early.

9. Whichever method is used, overboard discharge during deballasting must be

  • A. Below the waterline
  • B. Above the waterline
  • C. Without restriction
  • D. None of the above
Answer: B — Above the waterline
MARPOL Annex I Regulation 30 requires discharge of ballast containing oil residues to be made above the waterline so that any oil can be visually observed, except under specified conditions for segregated or clean ballast.

10. A chemical tanker constructed on or after 1 July 1986 must comply with the provisions of the

  • A. BCH Code
  • B. IGC Code
  • C. IBC Code
  • D. GC Code
Answer: C — IBC Code
The IBC Code is mandatory under SOLAS Chapter VII and MARPOL Annex II for chemical tankers constructed on or after 1 July 1986. Older chemical tankers follow the BCH Code; the IGC and GC Codes apply to gas carriers.

11. During loading, the ullage and temperature measuring equipment shows a low battery. Where can the battery be replaced?

  • A. On deck in the tank area
  • B. Near the manifold area
  • C. At the pump room entrance
  • D. Only inside the accommodation (gas-safe area)
Answer: D — Only inside the accommodation (gas-safe area)
Changing batteries of intrinsically safe equipment can produce sparks and may invalidate its certification, so ISGOTT requires this to be done only in a gas-safe area such as the accommodation, never in the cargo area.

12. When operating with a negative suction head, which of these types of pumps will require priming?

  • A. Reciprocating
  • B. Gear
  • C. Centrifugal
  • D. Rotary screw
Answer: C — Centrifugal
A centrifugal pump cannot create enough suction to lift liquid when the casing is full of air or vapour, so it must be primed. Positive displacement pumps such as reciprocating, gear and screw pumps are self-priming.

13. Which of the following is almost absent in crude petroleum?

  • A. Olefins
  • B. Naphthenes
  • C. Mercaptans
  • D. Cycloparaffins
Answer: A — Olefins
Crude oil consists mainly of paraffins, naphthenes (cycloparaffins) and aromatics, with sulphur compounds such as mercaptans in sour crudes. Olefins are unsaturated and virtually absent in crude; they are formed during cracking processes.

14. A ____ tanker is a vessel in the size range of about 50,000 to 74,999 dwt.

  • A. Aframax
  • B. Panamax
  • C. Suezmax
  • D. VLCC
Answer: B — Panamax
Panamax tankers are the largest that could transit the original Panama Canal locks, typically about 50,000 to 75,000 dwt. Aframax are about 80,000 to 120,000 dwt, Suezmax about 120,000 to 200,000 dwt, and VLCCs above 200,000 dwt.

15. The tank washing machines for crude oil washing shall be ____ mounted and of a design acceptable to the Administration.

  • A. Temporarily
  • B. Permanently
  • C. Portably
  • D. None of the above
Answer: B — Permanently
The Revised Specifications for COW systems under MARPOL Annex I require COW machines to be permanently mounted in the tanks and of a design acceptable to the Administration, with supply lines fixed.

16. On tankers, impairment of the sense of smell is especially serious with mixtures containing

  • A. Hydrocarbons
  • B. Carbon dioxide
  • C. Hydrogen sulphide
  • D. Sulphur dioxide
Answer: C — Hydrogen sulphide
Hydrogen sulphide quickly paralyses the sense of smell at concentrations above about 100 ppm, so personnel may wrongly believe the gas has gone. ISGOTT warns that smell must never be relied on to detect H2S.

17. The monitors of the deck foam system are arranged to lay foam across the

  • A. Cargo deck
  • B. Forecastle deck
  • C. Poop deck
  • D. Weather deck forward of the forecastle
Answer: A — Cargo deck
SOLAS II-2/4.5.5 and FSS Code Chapter 14 require tankers to have a fixed deck foam system with monitors able to deliver foam to the entire cargo tank deck area and into any tank whose deck is ruptured.

18. Before boiler flue gas can be used for inerting cargo tanks, it must first be

  • A. Used directly as it leaves the uptake
  • B. Heated to prevent condensation
  • C. Cooled and cleaned in a scrubber tower
  • D. Mixed with fresh air to reduce CO2
Answer: C — Cooled and cleaned in a scrubber tower
Flue gas leaving the boiler is hot and contains soot and sulphur oxides, so it is not used directly. FSS Code Chapter 15 requires a scrubber to cool the gas and remove solids and sulphur compounds before the blowers deliver it to the tanks.

19. A hydrocarbon gas mixture cannot burn when the oxygen content is reduced below approximately

  • A. 5% by volume
  • B. 15% by volume
  • C. 11% by volume
  • D. 21% by volume
Answer: C — 11% by volume
ISGOTT's flammability diagram shows that no hydrocarbon gas/air mixture can burn if the oxygen content is below about 11% by volume. For a safety margin, cargo tanks are kept at 8% oxygen or less.

20. Smoking on board may be carried out only at places designated by the ____ of the ship.

  • A. Chief engineer
  • B. Chief officer
  • C. Master
  • D. Bosun
Answer: C — Master
ISGOTT requires smoking on tankers to be permitted only in designated smoking places, which are authorised by the master in agreement with the terminal; smoking is prohibited everywhere else on board.

21. The effect of free surface of liquids in slack tanks on a ship's stability is to

  • A. Increase the metacentric height
  • B. Reduce the effective metacentric height
  • C. Lower the centre of gravity
  • D. Have no effect on stability
Answer: B — Reduce the effective metacentric height
Liquid moving in a slack tank shifts towards the low side when the ship heels, causing a virtual rise in the centre of gravity. This reduces the effective GM and the righting lever, so free surface disturbs stability.

22. Which statement is correct regarding fire-fighting procedures in port compared to at sea?

  • A. They are exactly the same in both cases
  • B. They differ, as in port the terminal and shore fire services must be alerted and coordinated with
  • C. Fire fighting in port is the sole responsibility of the terminal
  • D. At sea the ship can always rely on outside assistance
Answer: B — They differ, as in port the terminal and shore fire services must be alerted and coordinated with
In port, ISGOTT requires the ship to raise the alarm with the terminal, stop cargo operations and coordinate with shore fire-fighting services, and the ship may need to be removed from the berth, whereas at sea the crew must manage alone.

23. Under MARPOL Annex I Regulation 19, double-hull protection of the cargo tank length is required for oil tankers of what size delivered on or after 6 July 1996?

  • A. 5,000 tonnes deadweight and above
  • B. 20,000 tonnes deadweight and above
  • C. 30,000 tonnes deadweight and above
  • D. 150 gross tonnage and above
Answer: A — 5,000 tonnes deadweight and above
MARPOL Annex I Reg.19 requires oil tankers of 5,000 tonnes deadweight and above delivered on or after 6 July 1996 to have the cargo tank length protected by wing tanks and double-bottom tanks or spaces; smaller tankers have reduced double-bottom requirements.

24. For an oil tanker of 5,000 tonnes deadweight and above, MARPOL Annex I Regulation 19 sets the minimum width of the wing tanks or spaces at

  • A. 0.76 m
  • B. 1.0 m
  • C. 2.0 m
  • D. 1.5 m
Answer: B — 1.0 m
Reg.19 gives the wing width as w = 0.5 + DW/20,000 m or 2.0 m, whichever is less, but the width may in no case be less than 1.0 m.

25. The required depth of the double bottom of an oil tanker of 5,000 tonnes deadweight and above under MARPOL Annex I Regulation 19 is

  • A. B/10 or 3.0 m, whichever is less, but not less than 1.5 m
  • B. B/20 or 1.5 m, whichever is greater
  • C. B/15 or 2.0 m, whichever is less, but not less than 1.0 m
  • D. A fixed 2.0 m irrespective of breadth
Answer: C — B/15 or 2.0 m, whichever is less, but not less than 1.0 m
MARPOL Annex I Reg.19.3.2 requires the double-bottom height h to be B/15 or 2.0 m, whichever is the lesser, with a minimum value of 1.0 m, where B is the moulded breadth of the ship.

26. Under MARPOL Annex I Regulation 18, segregated ballast tanks are required on every crude oil tanker of 20,000 tonnes deadweight and above and on every product carrier of

  • A. 5,000 tonnes deadweight and above
  • B. 40,000 tonnes deadweight and above
  • C. 70,000 tonnes deadweight and above
  • D. 30,000 tonnes deadweight and above
Answer: D — 30,000 tonnes deadweight and above
MARPOL Annex I Reg.18 requires segregated ballast tanks in every crude oil tanker of 20,000 tdw and above and every product carrier of 30,000 tdw and above, with capacity sufficient to meet the draught and trim requirements without using cargo tanks for ballast.

27. As defined in MARPOL Annex I, 'segregated ballast' means ballast water

  • A. introduced into a tank completely separated from the cargo oil and fuel oil systems and permanently allocated to ballast
  • B. carried in a cargo tank that has been crude oil washed
  • C. carried in a cargo tank after water washing and gas freeing
  • D. held in the slop tank for decanting through the ODME
Answer: A — introduced into a tank completely separated from the cargo oil and fuel oil systems and permanently allocated to ballast
MARPOL Annex I Reg.1 defines segregated ballast as ballast water introduced into a tank which is completely separated from the cargo oil and fuel oil system and which is permanently allocated to the carriage of ballast or of non-oil cargoes.

28. MARPOL Annex I Regulation 23 (accidental oil outflow performance) applies to oil tankers of 5,000 tonnes deadweight and above delivered

  • A. On or after 6 July 1996
  • B. On or after 1 January 2010
  • C. On or after 1 February 2002
  • D. On or after 1 January 2016
Answer: B — On or after 1 January 2010
Reg.23 requires oil tankers of 5,000 tdw and above delivered on or after 1 January 2010 to meet a mean oil outflow parameter, which in practice limits the size and arrangement of cargo tanks to reduce oil spilled after collision or grounding.

29. On a conventional oil tanker, the purpose of a cofferdam between the cargo tank block and the machinery space is to

  • A. Store slops from tank washing
  • B. Act as an emergency ballast tank
  • C. Provide a void isolating space so that cargo leakage or vapour cannot pass directly into the machinery space
  • D. Hold the inert gas supply for the cargo tanks
Answer: C — Provide a void isolating space so that cargo leakage or vapour cannot pass directly into the machinery space
SOLAS II-2/4.5.1 requires cargo tanks and slop tanks to be segregated from machinery spaces by cofferdams, cargo pump rooms, oil bunker tanks or ballast tanks, so that a leak of cargo or vapour cannot reach a space with ignition sources.

30. A tanker described as a VLCC normally falls in which deadweight range?

  • A. About 50,000 to 75,000 tonnes
  • B. About 80,000 to 120,000 tonnes
  • C. Above 500,000 tonnes
  • D. About 200,000 to 320,000 tonnes
Answer: D — About 200,000 to 320,000 tonnes
In common industry size classification, a Very Large Crude Carrier is about 200,000 to 320,000 dwt, above Suezmax size and below the ULCC class, and is used mainly on long-haul crude trades.

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