The Strait of Istanbul, the narrow waterway separating Europe from Asia, holds a strategic importance in maritime transportation as it links the Black Sea to the Mediterranean. It is considered as one of the world's most congested and difficult-to-navigate waterways. Over 55,000 transit vessels pass through the Strait annually, roughly 20% of which carry dangerous cargo. In this study, we have analyzed safety risks pertaining to transit vessel maritime traffic in the Strait of Istanbul and proposed ways to mitigate them. Safety risk analysis was performed by incorporating a probabilistic accident risk model into the simulation model. A mathematical risk model was developed based on probabilistic arguments regarding instigators, situations, accidents, consequences, and historical data, as well as subject-matter expert opinions. Scenario analysis was carried out to study the behavior of the accident risks, with respect to changes in the surrounding geographical, meteorological, and traffic conditions. Our numerical investigations suggested some significant policy indications. Local traffic density and pilotage turned out to be two main factors affecting the risks at the Strait of Istanbul. Results further indicate that scheduling changes to allow more vessels into the Strait will increase risks to extreme levels. Conversely, scheduling policy changes that are opted to reduce risks may cause major increases in average vessel waiting times. This in turn signifies that the current operations at the Strait of Istanbul have reached a critical level beyond which both risks and vessel delays are unacceptable.

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Risk Analysis of the Vessel Traffic in the Strait of Istanbul

http://www.seas.gwu.edu/~dorpjr/Publications/TechnicalReports/NSFProject/RESS2003.pdf

A traffic density analysis of proposed ferry service expansion in San Francisco Bay using a maritime simulation model

Is it safer for New Orleans river gambling boats to be underway than to be dockside? Is oil transportation risk reduced by lowering wind restrictions from 45 to 35 knots at Hinchinbrook Entrance for laden oil tankers departing Valdez, Alaska? Should the International Safety Management (ISM) code be implemented fleet-wide for the Washington State Ferries in Seattle, or does it make more sense to invest in additional life craft? Can ferry service in San Francisco Bay be expanded in a safe manner to relieve high way congestion? These risk management questions were raised in a series of projects spanning a time frame of more than 10 years. They were addressed using a risk management analysis methodology developed over these years by a consortium of universities. In this paper we shall briefly review this methodology which integrates simulation of Maritime Transportation Systems (MTS) with incident/accident data collection, expert judgment elicitation and a consequence model. We shall describe recent advances with respect to this methodology in more detail. These improvements were made in the context of a two-year oil transportation risk study conducted from 2006–2008 in the Puget Sound and surrounding waters. An application of this methodology shall be presented comparing the risk reduction effectiveness analysis of a one-way zone, an escorting and a double hull requirement in the same context.

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

Several major risk studies have been performed in recent years in the maritime transportation domain. These studies have had significant impact on management practices in the industry. The first, the Prince William Sound risk assessment, was reviewed by the National Research Council and found to be promising but incomplete, as the uncertainty in its results was not assessed. The difficulty in assessing this uncertainty is the different techniques that need to be used to model risk in this dynamic and data-scarce application area. In previous articles, we have developed the two pieces of methodology necessary to assess uncertainty in maritime risk assessment, a Bayesian simulation of the occurrence of situations with accident potential and a Bayesian multivariate regression analysis of the relationship between factors describing these situations and expert judgments of accident risk. In this article, we combine the methods to perform a full-scale assessment of risk and uncertainty for two case studies. The first is an assessment of the effects of proposed ferry service expansions in San Francisco Bay. The second is an assessment of risk for the Washington State Ferries, the largest ferry system in the United States.

/pdf/speaking-the-truth-in-maritime-risk-assessment-2jdlv0fko4.pdf

Speaking the Truth in Maritime Risk Assessment

Ship grounding accidents, being one of the major types of maritime accidents, are significant failures putting in danger maritime transportation systems. Moreover, the risks associated with those failures can be catastrophic for the system, society, and the environment. This highlights the importance of appropriate methodology for assessing and managing the associated risk. Many scholars have introduced a wide range of methods for modeling the risk, utilizing the concept of the probability and the consequence of an accident; however, those models very often employ critical assumptions on the behavior of maritime transportation systems, which may seem not to be supported by evidences. This in turn limits models' ability to mitigate the risks, as those simply remain unknown. Therefore, this article has three aims. First, it proposes a methodological framework suitable for knowledge-based risk modeling, fulfilling the recommendations given by the Formal Safety Assessment issued by the International Maritime Organization. Secondly, it thoroughly reviews and discusses all the existing risk models available in the literature developed for ship grounding risk analysis in light of the proposed risk perspective. Third, the models that are more appropriate for risk management and decision making are highlighted and the recommendations are given to future model developments.

Modeling the risk of ship grounding—a literature review from a risk management perspective

We formulate a Bayesian model to estimate the physical risk of grounding during transits into and out of port as a function of potential risk factors We assemble and analyze information on factors surrounding groundings in three US ports between 1981 and 1995 Although the data are far from perfect, it is possible to establish associations between grounding risk and changes in factors such as vessel type and size, wind speed, and visibility

Vassilis Papakonstantinou

Papers

Investigation of Potential Risk Factors For Groundings of Commercial Vessels In U.S. Ports

Formulation of a model for ship transit risk

Evaluation of the physical risk of ship grounding