Free Tanker Familiarization Tanker Safety Systems Questions and Answers

Question 1

What is the primary function of an Inert Gas System (IGS) on board an oil tanker?

Accepted Answer

To render the cargo tank atmosphere non-flammable by reducing the oxygen content.

Answer

The Inert Gas System (IGS) is a critical safety feature that introduces flue gas or nitrogen into cargo tanks. This process displaces the air, reducing the oxygen level to below 8%, which is insufficient to support combustion, thereby preventing fire and explosion.

Question 2

During cargo discharge, the liquid level in a tank drops, which can create a vacuum. Which safety device automatically allows air or inert gas to enter the tank to prevent structural damage from under-pressure?

Accepted Answer

Pressure/Vacuum (P/V) valve

Answer

A Pressure/Vacuum (P/V) valve is designed to protect the tank from both overpressure and vacuum conditions. During discharge, as the liquid level falls, the vacuum side of the valve opens automatically to let air or inert gas in, equalizing the pressure and preventing the tank from collapsing.

Question 3

Which of the following best describes the distinction between a high-level alarm and an overfill alarm on a chemical tanker?

Accepted Answer

The high-level alarm is a pre-warning (e.g., at 95% full), while the overfill alarm is a final warning (e.g., at 98% full) that may trigger a shutdown.

Answer

High-level and overfill alarms are independent systems. The high-level alarm typically activates at 95% of tank capacity to warn operators to reduce the loading rate. The overfill alarm, a critical safety device, activates at a higher level, typically 98%, and is designed to give a final warning and often initiates an automatic shutdown of the loading operation to prevent a spill.

Question 4

A cofferdam on a tanker is a specific type of void space. What is its main safety purpose?

Accepted Answer

To isolate tanks containing incompatible substances or to separate cargo tanks from non-cargo areas.

Answer

A cofferdam is an empty compartment designed to provide a physical separation between two adjacent spaces. Its purpose is to prevent the leakage and intermixing of liquids from adjoining tanks (e.g., cargo and fuel oil, or two different reactive cargoes) or to separate hazardous cargo areas from machinery or accommodation spaces.

Question 5

In the event of a major cargo hose failure or fire at the manifold during transfer operations, which system is designed to quickly stop the flow of cargo in a controlled manner?

Accepted Answer

The Emergency Shutdown (ESD) system

Answer

The Emergency Shutdown (ESD) system is designed for exactly this type of emergency. When activated, it quickly and safely stops the cargo transfer by closing valves and stopping pumps in a predetermined sequence to minimize the consequences of a hazardous event like a hose burst or fire.

Tanker Familiarization Practice Test

Tanker Familiarization Practice Test

Free Tanker Familiarization Tanker Safety Systems Questions and Answers