Maritime oil tanker casualties (1964-1977) : an analysis of safety and policy issues

The major premise of the study is that identifying the true causes of tanker casualties has been difficult because existing methods for collecting and reporting information about such casualties are inadequate and are in need of major modification and improvement. Existing systems suffer from limited coverage and insufficient detail. In addition, reporting is voluntary and erratic, with many nations choosing to withhold some or all information regarding casualties. Relevant information is uncorrelated and scattered among many diverse sources. Preceding studies in the area have either suffered from limited coverage or from accusations of bias because they have been performed by those who have vested interests or previously determined positions to defend.

Data and information for the study were obtained from diverse sources reflecting the global nature of the research. Participants included individuals, companies, environmental groups, government agencies, United Nations organizations and tanker owners. The acquired information fell into two categories: statistical data and qualitative information.

Statistical data was tested for trends in and/or relationships between the variables specified for study. In all cases the dependent variable was the frequency of casualty occurrence. Independent variables were those selected for use in the study. Trend analysis was accomplished by use of linear regression coupled with t-tests for significance. Relationships were analyzed by use of the Freidman S Test for Randomized Block Designs and the Wilcoxon Ranked Sum Sign test. Each test was analyzed and the highest level of statistical significance for each test was reported.

Qualitative, non-statistical information was compiled, analyzed and the results reviewed and synthesized with the results of the statistical analysis. Both results were then summarized and discussed as to how they relate to the international maritime environment.

From the study results it may be concluded that the primary factor affecting the frequency with which tanker casualties occur is the nature of ownership of vessels. Those individuals or entities who are in direct control of the vessel are the ones determining the character and qualification of the crew and the condition of the vessel. Next in importance as a factor is the attitude and capability of the nation whose flag the vessel flies. The accident record of open registry nations is poorer than that of regulated registries and is reflective of the fact that they lack the facilities, expertise and administrative machinery to develop, administer and enforce effective standards regarding the qualifications of crew and the condition of vessels.

No evidence was found to indicate that the size of oil tankers has any effect upon the frequency with which they become casualties. Vessel age displayed a high correlation with casualty frequency. Tankers over 10 years of age present a high risk with vessels between 15 and 19 years of age being particularly vulnerable.

The study also concluded that we need more cooperation and attention in regard to the qualifications and licensing of crews and in regard to the licensing and inspection of vessels. Future efforts must be devoted to developing a worldwide system of standards and enforcement to prevent unqualified crews and irresponsible operators from operating dangerous sub-standard tankers.

Finally, the study concluded that we need more and better information about oil tanker accidents and their causes. In particular, we lack information about the human factor and its effect on casualty frequency.