Segregated Ballast VLCCs: An Economic and Pollution Abatement Analysis

Abstract

This paper presents the results of a study of very large crude carriers (VLCCs) to determine the cost and effectiveness of variations in the capacity of segregated ballast and variations in arrangement expected to reduce oil pollution due to operational and accidental causes. The arrangements considered include double bottoms, double sides, double skin, and alternating cargo and ballast wing tanks. The paper concentrates on a series of 250,000-dwt tankers, but does consider the influence of size by including results for tankers of 120,000 dwt and 477,000 dwt. The degree of effectiveness is estimated for both operational and accidental pollution based on the best available data. Sensitivity studies are provided to check general conclusions. Finally, estimates of the cost of preventing one cubic meter of oil pollution with each design are presented. A discussion of operating factors subject to a reduction in performance as a result of design features is given.