A systems approach to managing oil transportation risk in Prince William Sound

Abstract

The grounding of the Exxon Valdez caused public and government concern about the safety of oil transportation in the Prince William Sound, Alaska. As a result, a large number of proposals and recommendations were made to improve safety, but stakeholders could not achieve a consensus on their effectiveness at reducing risk. A steering committee representing all local stakeholders, including the Prince William Sound Shipping Companies, the Prince William Sound Regional Citizens Advisory Committee, the Alaska Department of Environmental Conservation, and the U.S. Coast Guard, was formed to address the issue of risk intervention effectiveness. The Steering Committee hired a team of consultants who were charged with assessing the current risk of accidents involving oil tankers operating in the Prince William Sound and evaluating measures aimed at reducing this risk. The team created a detailed model of the Prince William Sound oil transportation system, using system simulation, data analysis, and expert judgment, capable of answering the majority of the questions posed by the Steering Committee. The success of the project has been demonstrated by the acceptance of the major recommendations by all stakeholders and has, to date, resulted in multi-million dollar investments.

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

“…The MTS simulation also has built in it an hourly simulation of environmental variables such as wind, visibility and, recently, currents. Merrick et al (2000Merrick et al ( , 2003 describe in more detail the construction of such a maritime simulation which has been coded over time directly in Pascal and does not use a pre-existing simulation platform. Each generated accident scenario is recorded to a database describing its accident and consequence descriptors, accident type and incident type preceding the accident.…”

“…Moreover, synergistic effects of a group of risk intervention measures could lead to unintended consequences. For example, the simultaneous implementation of 162 planned risk intervention measures in the PWS risk assessment analysis (Merrick et al 2000) led to an evaluated oil transportation risk of zero, but also brought oil transportation throughput in the simulation to a grinding halt. MTS simulations are a natural platform to test for potential synergistic effects of the implementation of a set of risk interventions.…”

“…Thus, e.g., 12 knots was converted to a one nautical mile radius. In Merrick et al (2000Merrick et al ( , 2003 and van Dorp et al (2001) this distance was held constant regardless of the VOI's speed. The Fig.…”

“…In Merrick et al (2000Merrick et al ( , 2002 grounding accident locations where analyzed as a function of the location of the potential incident occurring. Calculation power at the time prevented on-the-fly drifting path evaluations and a separate vessel drift simulator was developed (Merrick 2002) to evaluate potential shore locations of grounding accidents.…”

“…2 we shall present an overview of the risk management analysis methodology described in more detail in Merrick et al (2000Merrick et al ( , 2001Merrick et al ( , 2002Merrick et al ( , 2003 and van Dorp et al (2001). This methodology centers around a causal chain analysis (depicted in Fig.…”