Challenge: The United States Coast Guard was tasked by the Congress to conduct studies to evaluate the adequacy of navigation equipment on tankers, position reporting systems on tankers, and navigation procedures under different operating conditions and to determine the appropriate manning level for United States tankers. The Coast Guard was also tasked to examine the limits of liabilities for transportation-related onshore facilities. These Congressional concerns were expressed in the Oil Pollution Act of 1990 (OPA 90).
Accomplishment: The DSRD project team delivered three comprehensive reports (Appropriate Crew Size, Adequacy of Tanker Navigation Equipment and Operating Procedures, and Limits of Liability), that summarized previous studies, the results of DSRD investigations of tanker operations, and the DSRD team's recommendations. These recommendations were based on current laws and regulations, tanker operations and procedures, transportation-related onshore facilities, and current and near future technology and financial options. The analyses and recommendations were to be submitted to Congress by the Coast Guard. In addition, we delivered a report on an innovation in managing vessel (including tankers) traffic services (The LOPOS System Demonstration).
Technologies Employed: Many operations research techniques were employed in this project, ranging from the mathematics of linear regression to classical operational analyses.
Figure 1. Study Flow
Background: The Argo Merchant oil spill off the coast of Massachusetts in 1976 caused a public outcry that occupied both houses of the United States Congress with hearings and discussions regarding prevention, clean-up, and payment for oil spills from tanker accidents, culminating in passage of the Clean Water Act of 1977. Ironically, Congress had earlier identified Alaska's Valdez Narrows as being of special concern, but had not yet taken statutory action when the Exxon Valdez ran aground on Bligh Reef in March, 1989. Public reaction was fervent and Congressional action was swift: OPA 90 became Public Law 101-380 in August, 1990.
Results: The DSRD team examined the issues related to safe navigation and manning levels with respect to oil tankers. As an example, the chart below shows the experience of one large shipper with respect to oil spills and reduction in manning levels. This same relationship of reduced manning levels being accompanied by reduced oil spills held true for the industry as a whole.
The team examined the causal links, as shown below. It found that maritime casualties have human error as a major cause and that fatigue is a major cause of human error; however, it also found that crew reduction has not caused maritime casualties and need not be a cause of fatigue (given the introduction of proper mitigating forces, such as technology and procedures). These findings were detailed in Appropriate Crew Size: An Oil Pollution Act of 1990 Study on Safe Navigation and Manning, K/DSRD-1652, 1995, and OPA 90 Studies on Adequacy of Tanker Navigation Equipment, Systems, and Procedures, K/DSRD-1648/R1, 1995.
A subsidiary report, Vessel Traffic Services: The LOPOS System Demonstration, K/DSRD-2081, 1996, described the available technology with respect to port traffic. Vessel Traffic Services (VTS) were in place in several areas, notably in Europe; however, there are several variations in the systems. As shown in the figure below, most used centralized control and were government operated. Some such as the Los Angeles/Long Beach port VTS used centralized control but had private or mixed government and private operators. The proposed system for Tampa Bay, examined in this report, would use a decentralized control system, which looked promising.
The third major report, Research Report on the Oil Pollution Act of 1990: Limits of Liability for Transportation-Related Onshore Facilities, K/DSRD-2069, 1996, examined the potential effects of setting liability limits for oil spills for ground transportation (i.e., pipelines, trucks, and trains). As shown below, there are two types of costs to be examined, spill costs (direct and indirect) and risk costs (e.g., insurance and prevention measures).
In notional terms, increasing the liability limit leads to lower spill costs, as the number of spills are reduced. However, increased liability limits also increase costs for the carriers (which costs are passed on to the consumers) in the form of increased insurance policy costs and increased costs to prevent and mitigate the effects of oil spills. The total of these categories of costs is the total societal cost in the diagram. Depending on the shapes of the actual curves, there may be a point of minimal total societal cost. At this point lower liability limits and higher liability limits lead to higher total costs to society. The bulk of the research was in determining the nature of these curves, based on historical data and potential future variations.
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