Date of Award


Document Type


Degree Name

Master of Science in Maritime Affairs


Maritime Education & Training


Malmö, Sweden



First Advisor

Zade, Günther.


This dissertation is a study and analysis of the control of tank atmospheres in oil tankers. It reveals the various aspects of hazards and points out the required prevention for each possible problem related to them. In the introduction, the dissertation outlines its aim, scope, reasons and basic concepts. A study is made on static electricity within cargo tanks, examining how the electrostatic charges are generated and what are the necessary precautions to be taken for safe operations. The origin of mineral oil, its chemical structure and physical properties are described. Then, the different types of tank atmospheres, control of same and safe tanker operations for each situation, including tank-cleaning, gas-freeing and ventilation, are also covered. Flammability hazards, inert gas operations and the control of environmental pollution are also described. Finally, some suggestions on the control of vapour emissions and ventilation of double hull spaces have been given. It is hoped that this dissertation will be of benefit to practising ship officers of oil tankers and lecturers on oil tanker courses in MET institutions, as it explains in a simplified way the problems, hazards and control of tank atmospheres on oil tankers.