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OCTCO/OCTF exit exam questions and answers — Set 7

Set 7 of the Oil and Chemical Tanker Cargo Operations (OCTCO/OCTF) exit exam bank — 30 of 252 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 7 — 30 OCTCO/OCTF exit exam questions with answers

1. Gas testing onboard tankers can be carried out with the following equipment onboard?

  • A. MMC
  • B. Thermometer
  • C. Gas instrument
  • D. Sample
Answer: C — Gas instrument
Atmospheric gas testing on board tankers is conducted using calibrated multi-gas instruments, oxygen analyzers, combustible gas indicators (explosimeters), and toxic gas detectors.

2. What % of air is made up by oxygen?

  • A. 78%
  • B. 21%
  • C. 100%
  • D. 4%
Answer: B — 21%
Standard atmospheric ambient air is composed of approximately 20.9% (approx. 21%) oxygen, 78% nitrogen, and 1% argon and other trace gases.

3. Does the muster list and the emergency instruction contain information relevant only to the deck officers?

  • A. Yes
  • B. No
  • C. No, all crew members and other personnel onboard
  • D. No relevant to all offices
Answer: C — No, all crew members and other personnel onboard
The shipboard muster list and emergency station bill specify emergency duties and muster stations for all crew members and personnel on board.

4. COW operation is conducted during?

  • A. Discharging operation
  • B. Tank cleaning operation
  • C. Loading operation
  • D. Gas freeing operation
Answer: A — Discharging operation
Crude Oil Washing (COW) is carried out concurrently during cargo discharge operations using the liquid crude cargo as the washing medium under an inert atmosphere.

5. Before cargo operations start the master should establish liaison between the ship and______?

  • A. The terminal
  • B. The flag state administration
  • C. The port authority
  • D. The arbor controls
Answer: A — The terminal
Prior to starting any cargo handling operations, the ship Master/Chief Officer must establish clear communication and operational liaison with the terminal representative.

6. If at sea the inert gas low pressure alarm is activated it may be necessary to conduct____?

  • A. Cargo heating operations to raise the pressure
  • B. Cargo transfer operation to raise the pressure
  • C. Inert gas topping up operations
  • D. Reduce engine speed to allow safe ingress of atmospheric air
Answer: C — Inert gas topping up operations
If the inert gas low-pressure alarm activates during a loaded sea passage, the crew must initiate inert gas topping-up operations to restore positive pressure in the cargo tanks.

7. When oil temperature rises, the volume _______?

  • A. Varies
  • B. Reduces
  • C. Increases
  • D. Remain the same
Answer: C — Increases
When the temperature of an oil cargo increases, the liquid expands in volume and its density correspondingly decreases.

8. An important publication required to be approved by the flag state and carried onboard chemical tankers?

  • A. The procedure and arrangements manual
  • B. The operation manual
  • C. The arrangements manual
  • D. The procedures manual
Answer: A — The procedure and arrangements manual
Under MARPOL Annex II, every chemical tanker must carry an approved Procedures and Arrangements (P&A) Manual describing physical equipment, washing procedures, and discharge arrangements.

9. The low velocity fog applicator used in conjunction with the all-purpose firefighting nozzle, should always be_______________?

  • A. Stored in the rack when not in actual use
  • B. Attached to the nozzle by the chain
  • C. Coated with heavy grease to prevent corrosion
  • D. Left in place in the all –purpose nozzle
Answer: A — Stored in the rack when not in actual use
Low-velocity fog applicators used with dual-purpose firefighting nozzles should be safely stowed in their dedicated storage racks when not in active firefighting use.

10. Which safety device is fitted on the inert gas scrubber tower to monitor the efficient operation of the plant?

  • A. The inert gas low flow alarm
  • B. The scrubber tower high level alarm
  • C. The scrubber tower low pressure & non flow alarm of cooling tower
  • D. Both (B) & (C)
Answer: D — Both (B) & (C)
The inert gas scrubber tower is protected by safety interlocks and alarms for high water level (to prevent flooding the flue gas line) and low cooling water flow/pressure.

11. In the event of cargo spillage, which of following would be informed first?

  • A. The clean-up contractor
  • B. The agent
  • C. The ship owner
  • D. The port authority
Answer: D — The port authority
In the event of an accidental cargo spillage during port operations, the port authority and coast guard/coastal state administration must be notified immediately as per the SOPEP/SMPEP.

12. One of the requirements for the crude oil washing on tankers is that an inert gas system be fitted, according to regulations supply of an inert gas system can be have portable connection to which space other than cargo tank?

  • A. Every cargo tanks
  • B. Every cargo and slop tank and cofferdam
  • C. Every cargo and slop tank
  • D. Every cargo tank, slop tank, cofferdam and ramp space
Answer: C — Every cargo and slop tank
Under SOLAS regulations, inert gas supply lines are permanently connected to all cargo and slop tanks to maintain positive inert overpressure at all times.

13. High IG temperature trip is about___?

  • A. 55C
  • B. 65C
  • C. 85C
  • D. 75C
Answer: D — 75C
The high inert gas temperature trip on an IGS plant automatically shuts down the gas supply if the gas leaving the scrubber exceeds 75°C to protect downstream equipment and deck seals.

14. The flammable range of different chemicals may be ___?

  • A. Always the same
  • B. The same
  • C. Often different
  • D. Always different
Answer: D — Always different
Different chemical and hydrocarbon products have widely differing lower and upper explosive limits (flammable ranges) depending on their molecular structure and volatility.

15. The apparatus consists of double opposed nozzles which rotate slowly about their horizontal and vertical axis and project two streams of water through all possible angles against all inside surfaces of the space being cleaned.

  • A. Crude oil washing machines
  • B. Butterworth tank cleaning machine
  • C. Manually operated deck tube nozzle machine
  • D. All of the above (A) (B) (C) or combinations of attachment
Answer: B — Butterworth tank cleaning machine
The Butterworth tank cleaning machine consists of dual or multiple rotating nozzles driven by water pressure that revolve through vertical and horizontal planes to wash all internal tank bulkheads.

16. Pyrophoric iron sulphide is formed:

  • A. In the presence of oxygen
  • B. In presence of H2S
  • C. When rust is formed in tanks
  • D. All of the above
Answer: D — All of the above
Pyrophoric iron sulphide forms inside crude tanks when iron rust (iron oxide) reacts with hydrogen sulphide (H2S) in an oxygen-depleted atmosphere.

17. It is the lowest liquid temperature at which the small flame initiates a flash of flame across the surface of the liquid, there by indicating presence of flammable gas above the liquid?

  • A. Pour point
  • B. Flash point
  • C. Cloud point
  • D. None of the above
Answer: B — Flash point
Flash point is the lowest temperature at which a liquid gives off sufficient flammable vapour to ignite momentarily (flash) in the presence of an external ignition source.

18. What does ODME mean?

  • A. Oil detecting – master evaluating
  • B. Over board detecting measure equipment
  • C. Oil detection measure equipment
  • D. Oil discharge monitoring equipment
Answer: D — Oil discharge monitoring equipment
ODME stands for Oil Discharge Monitoring and Control Equipment, which continuously monitors and controls oil content in overboard discharges under MARPOL Annex I.

19. Which of the following is compulsory on ships fitted with inert gas?

  • A. No smoking is allowed in any place at all on the vessel
  • B. an entry permit is required each time a person enters the pump room for any reason
  • C. Notice is to be placed at entrance as required NO ENTRANCE WITHOUT PERMISSION OF RESPONSIBLE PERSON (C / O) inert gas
  • D. Three (3) breathing apparatus sets with spare bottles and a refilling compressor Is fitted in the forecastle
Answer: C — Notice is to be placed at entrance as required NO ENTRANCE WITHOUT PERMISSION OF RESPONSIBLE PERSON (C / O) inert gas
On tankers fitted with inert gas systems, prominent warning notices stating 'NO ENTRY WITHOUT PERMISSION OF RESPONSIBLE OFFICER' must be posted at entrances to inerted spaces.

20. All VLCC normally has cargo tank heating arrangement as?

  • A. Heating steam arrangement in the individual tanks by steam circulation
  • B. Deck heaters electrically heated for circulation through heaters
  • C. Deck steam heater heated by steam circulation
  • D. None of the above
Answer: C — Deck steam heater heated by steam circulation
Large crude carriers (VLCCs) utilize steam deck heaters or internal steam heating coils to maintain crude oil at the required carriage and discharge pumping temperatures.

21. ____ is considered as best material for IG blower impellers?

  • A. Chromium
  • B. Steel
  • C. Titanium
  • D. Aluminum
Answer: D — Aluminum
Inert gas blower impellers are typically manufactured from aluminum alloys or non-ferrous materials to prevent mechanical frictional sparking in case of casing contact.

22. IG blowers are to be fitted with inlet and outlet valves in gas line with ___seats?

  • A. Copper
  • B. Aluminum
  • C. Leather
  • D. Rubber
Answer: D — Rubber
Inert gas blower isolating valves in flue gas lines are fitted with resilient rubber or elastomer seats to provide a gas-tight seal against corrosive flue gases.

23. There is an isolated fire on the poop deck, where should the master take control from?

  • A. The ship's office
  • B. The emergency headquarters
  • C. The incident sites
  • D. The bridge
Answer: D — The bridge
In the event of an emergency or poop deck fire, the Master commands and coordinates overall shipboard emergency response from the Bridge (Emergency Command Center).

24. When starting a stripping operation in a hydraulically operated centrifugal cargo oil pump system the following are the right path to follow?

  • A. Use a stripping vacuum system
  • B. The cargo wells are designed to carry out self-stripping
  • C. Use a separate stripping pump
  • D. All of the above as the system and attachment deemed fit
Answer: B — The cargo wells are designed to carry out self-stripping
Modern submerged centrifugal cargo pumping systems (such as Framo) utilize self-stripping wells and integrated stripping valves to drain tanks without requiring separate reciprocating stripping pumps.

25. The IBC code defines ___ types of chemical tankers?

  • A. 2
  • B. 3
  • C. 4
  • D. 5
Answer: B — 3
The IBC Code categorizes chemical tankers into three distinct ship types (Type 1, Type 2, and Type 3) based on the degree of hazard and damage survival capability required.

26. At which level will the slop system high level alarm sound?

  • A. 97%
  • B. 96%
  • C. 98%
  • D. 95%
Answer: D — 95%
Independent cargo and slop tank high-level alarms on tankers are set to activate audibly and visually when the liquid level reaches 95% volume capacity.

27. When operating with a negative suction head which of this type of pump is the best choice?

  • A. Reciprocating
  • B. Rotary
  • C. Gear
  • D. Centrifugal
Answer: A — Reciprocating
Positive-displacement reciprocating pumps create positive suction lift and are best suited for operating with a negative suction head or high vacuum conditions.

28. Loading through the pump discharge and recirculation line initially is _____?

  • A. Permissible
  • B. Done to increase the loading rate.
  • C. Normally the approved way to load all the cargo & slop tanks
  • D. To be avoided.
Answer: D — To be avoided.
Loading cargo initially through pump discharge and recirculation lines must be avoided to minimize splashing, turbulence, and static electricity generation.

29. When should employees be informed of the fire hazards to which they are exposed at work?

  • A. Upon the initial assignment
  • B. Within two days of the initial assignment
  • C. Within 30 days of the initial assignment
  • D. Within 90 days of the initial assignment
Answer: A — Upon the initial assignment
Occupational safety standards require all seafarers and terminal personnel to be informed of specific workplace fire hazards upon their initial assignment or onboarding.

30. A designated area within definite limits which has been accurately surveyed for clearance of sea bottom and submerged obstacles to a minimum indicated depth of water?

  • A. Designated routes
  • B. Safe shipping routes
  • C. Safe slop discharge routes
  • D. Deep water route
Answer: D — Deep water route
A deep-water route is a designated maritime routing measure accurately surveyed for clearance of the sea bottom and submerged obstacles for deep-draft vessels.

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