Date of Award
1997
Document Type
Dissertation
Degree Name
Master of Science in Maritime Affairs
Specialization
Maritime Safety Administration
Campus
Malmö, Sweden
Country
Republic of Korea
First Advisor
Langjord, Tore
Abstract
Numerous efforts have been made by international maritime communities to build environmentally sound tank ships and tanker designs have been changed accordingly through the years. Yet, tankers operating in the 21st Century will be expected to meet increasingly stringent environmental requirements. This dissertation is a study of design concepts of oil tankers for the prevention of oil pollution, examining each structural preventive method along with current design criteria stipulated in international legislations, especially in MARPOL 73/78. To facilitate the discussions on the evaluation and prevention method of oil spill, the chapter 2 briefly explains the physical mechanisms of oil outflow and the processes of cargo losses during contact accidents. The discussion further elaborates the complexity of collision and grounding phenomenon in estimating damage extents to calculate potential oil outflow. As an effective means to examine the environmental performance ofa tanker as well as a tool to ensure acceptability of new or alternative tanker design, both deterministic and probabilistic models of outflow estimation are investigated. The developments of tanker design in conjunction with changes of related regulations are explored. Furthermore, the advantages and disadvantages of each design, i.e., from Pre-MARPOL tanker to Double Hull tanker, are discussed. Further investigations are made to show the effectiveness of various preventive design methods together with examples and comparisons of both qualitative analysis and quantitative outflow. As a governing factor for ship's internal subdivision and tank arrangements, the stability performance of double hull tanker is widely discussed. The discussion aims at improving intact and damage stability through the change of structural arrangements within the defined minimum double hull sizes. The lolling problem of double hull tanker and IMO's ongoing debate in this urgent matter are also discussed. In this regard the author draws attention to the intact stability calculations performed for 5 tankers recently delivered or under construction by Korean ship yards. The results of the calculation are presented and analyzed to seek preventive solutions. Finally, all findings in each discussion have been summarized and proposed further studies are suggested. Recommendations are made with a view to possible adoption by the ship designers and changes of relevant regulations in the future.