An oil outflow model for tanker collisions and groundings

Abstract

In this paper we have developed an oil outflow model for collision and grounding accidents of tankers. The collision model explicitly links input variables such as tanker hull design (single or double), displacement and speed, striking vessel displacement and speed, and the interaction angle of both vessels to output variables: longitudinal and transversal damage extents of the tanker. Overlaying these damage extents on the tank vessel's design yields an oil outflow volume totaling the capacity of the damaged tank compartments. A similar model is developed for grounding accidents. A total of 80,000 simulation accident scenarios described in the National Research Council SR259 report published in 2001 served as the joint data set of input and output variables used in this "linking" process. The oil outflow model herein was designed keeping computational efficiency in mind to allow for its integration with a maritime transportation system (MTS) simulation. We shall demonstrate the use of the oil outflow model as a final analysis layer to evaluate doublehull effectiveness in a geographic context of an MTS simulation model developed for the oil transportation routes traversing the environmentally sensitive San Juan Islands area in Washington State.

Assessment of Ecological Vulnerability under Oil Spill Stress

“…The coastal ecological vulnerability values of all evaluation units were calculated based on Equation (1). For the calculated ecological vulnerability indexes, the k-means clustering algorithm was adopted and the ecologically-vulnerable regions of the gulf were divided into five regions, namely nonvulnerable, slightly vulnerable, moderately-vulnerable, vulnerable, and extremely vulnerable regions.…”

“…As the wharf is designed for 150,000 ton oil tankers, and a cabin can hold 8000 tons of oil, the amount of leakage was set as the maximum of a unilateral oil spill (8000 tons). The condensate of oil chosen for the maximum volume has a density of 740 kg/m 3 and tends to dissipate completely through evaporation within a few hours and does not normally form emulsions [1]. Case-selected leakage position trends and the direction of the wind in the most unfavorable combinations, which will have the largest impact in the selected gulf area as the oil spill situation, were established (Table 3).…”

“…An offshore oil spill accident will cause serious disasters to the ecosystem in the coastal areas. One example is the spill caused by the accident involving the tanker Exxon Valdez in 1989, which released about 36,000 tons of crude oil in Alaska, affecting 1500 km of coastline [1]; the spilled oil seriously affects coastal wild life and deeply impacts habitats and socio-economic activities. As the transitional zone between the sea and the land, the coastal zone has a rich and most valuable biosphere environment.…”

On a risk management analysis of oil spill risk using maritime transportation system simulation

“…Hence, the oil outflow model described in van de Wiel and van Dorp (2009) also allows for an evaluation of vessel fuel loss in addition to cargo spills of crude and petroleum products using a vessel's compartment design. To be able to accommodate diesel fuel and bunker fuel oil outflow calculations, Fig.…”

Turbulence modelling and role of compressibility on oil spilling from a damaged double hull tank

“…As a result, only the Froude similarity law was employed in early experimental studies, for example , and the viscous effects were ignored in the relevant analytical/empirical works (e.g. ) or numerical studies (e.g. ).…”