Tanker Familiarization Inert Gas Systems

Question 1

What is the primary purpose of an inert gas system (IGS) on a tanker?

Accepted Answer

To prevent explosive atmospheres in cargo tanks

Answer

To cool cargo tanks during transit

Answer

To increase cargo loading and discharge speed

Answer

To clean cargo tank residues after discharge

Question 2

What is the maximum allowable oxygen content by volume in a cargo tank that is considered properly 'inerted'?

Accepted Answer

8%

Answer

15%

Answer

21%

Answer

12%

Question 3

Which component of the inert gas system prevents cargo vapors from flowing back into the engine room?

Accepted Answer

Deck water seal

Answer

Pressure/vacuum (P/V) valve

Answer

Oxygen analyzer

Answer

Scrubber tower

Question 4

What is the most common source of inert gas on a crude oil tanker?

Accepted Answer

Flue gas from the ship's boiler or main engine exhaust

Answer

Nitrogen cylinders stored in the pump room

Answer

Carbon dioxide released from the fire suppression system

Answer

Compressed air from the engine room compressors

Question 5

What process describes reducing the oxygen content in a cargo tank to below 8% using inert gas?

Accepted Answer

Inerting

Answer

Purging

Answer

Gas-freeing

Answer

Ventilating

Question 6

According to SOLAS, inert gas systems are required on tankers with a minimum deadweight tonnage (DWT) of:

Accepted Answer

20,000 DWT

Answer

10,000 DWT

Answer

50,000 DWT

Answer

5,000 DWT

Question 7

What instrument is used to continuously monitor the oxygen content in the inert gas being supplied to cargo tanks?

Accepted Answer

Oxygen analyzer

Answer

Hydrocarbon vapor detector

Answer

Carbon monoxide meter

Answer

Combustible gas indicator (CGI)