THE DEVELOPMENT OF A RISK ASSESSMENT MODEL TO COMPARE OIL SPILL RISK FOR SINGLE & DOUBLE HULLED FPSOS

2008 ◽  
Vol 2008 (1) ◽  
pp. 725-731
Author(s):  
Nicholas Cavaye ◽  
Gina Waibl
Keyword(s):  
Risk Assessment ◽  
Oil Spills ◽  
Environmental Benefits ◽  
Assessment Model ◽  
Environmental Damage ◽  
Strong Argument ◽  
Accidental Discharge ◽  
Using Data ◽  
Oil Tankers ◽  
Double Hull

ABSTRACT In recent years, following a number of high profile oil spills internationally, there has been an increased focus on improving the safety of oil tankers to prevent the environmental damage caused by oil spills. Regulations developed focus on replacing single hulled trading tankers with a double hulled configuration. However, many of the risks associated with trading tankers do not apply to Floating Production, Storage and Offloading vessels (FPSOs). The risk assessment undertaken for this report compares single with double hull FPSOs, with respect to events causing serious environmental impact. The study considers external and on-board causes of events which may cause serious oil spills including fire, explosion, accidental discharge, grounding, collision and hull failure. The risk assessment comprises a limited quantitative analysis using data from the literature and observations from experience, which are consistently applied to each of the hazardous events identified as relevant. The report also looks at the wider environmental factors associated with single versus double hull FPSOs in order to inform policy makers. The findings indicate that risk profiles of oil tankers are markedly different from FPSOs, and that there is a strong argument that overall environmental risks from a single hull FPSOs are lower than those for a double hulled F?SO. A single sided hull has potentially better structural performance; no risk of inter-hull formation of volatile explosive mixtures; delivers environmental benefits; and has simpler operational requirements than a double sided FPSO. The main advantage for using a double sided hull is the higher collision impact energy it can withstand without releasing oil into the environment.

QUANTITATIVE RISK ASSESSMENT FOR COLLISIONS INVOLVING DOUBLE HULL OIL TANKERS

2021 ◽  
Vol 156 (A2) ◽  
Author(s):  
S A M Youssef ◽  
S T Ince ◽  
Y S Kim ◽  
J K Paik ◽  
F Chang ◽  
...  
Keyword(s):  
Risk Assessment ◽  
Structural Damage ◽  
Human Life ◽  
Quantitative Risk Assessment ◽  
Environmental Damage ◽  
Total Risk ◽  
Formal Safety Assessment ◽  
Environmental Damages ◽  
Oil Tankers ◽  
Double Hull

In recent decades, the safety of ships at sea has become a major concern of the global maritime industries. Ships are rarely subject to severe accidents during their life cycle. Collision is one of the most hazardous accidents, with potentially serious consequences such as the loss of human life, structural damage and environmental damage, especially if large tankers, LNG and/or nuclear-powered vessels are involved. This study presents a Quantitative Risk Assessment (QRA) for double hull oil tankers that have collided with different types of ships. The methodology used to perform the QRA is based on the International Maritime Organization’s (IMO) definition of a Formal Safety Assessment (FSA). Using probabilistic approaches, ship-ship collision scenarios are randomly selected to create a representative sample of all possible scenarios. The collision frequency is then calculated for each scenario. As this is a virtual experiment, the LS-DYNA nonlinear finite element method (NLFEM) is used to predict the structural consequences of each scenario selected. In addition, the environmental consequences are estimated by calculating the size of each scenario’s oil spill. To assess the economic consequences, the property and environmental damages are calculated in terms of monetary units. The total risk is then calculated as the sum of the resultant structural and environmental damages. Exceedance curves are established that can be used to define the collision design loads in association with various design criteria.

Quantitative Risk Assessment for Collisions Involving Double Hull Oil Tankers

2014 ◽  
Vol 156 (A2) ◽  
Keyword(s):  
Risk Assessment ◽  
Structural Damage ◽  
Human Life ◽  
Quantitative Risk Assessment ◽  
Environmental Damage ◽  
Total Risk ◽  
Formal Safety Assessment ◽  
Environmental Damages ◽  
Oil Tankers ◽  
Double Hull

In recent decades, the safety of ships at sea has become a major concern of the global maritime industries. Ships are rarely subject to severe accidents during their life cycle. Collision is one of the most hazardous accidents, with potentially serious consequences such as the loss of human life, structural damage and environmental damage, especially if large tankers, LNG and/or nuclear-powered vessels are involved. This study presents a Quantitative Risk Assessment (QRA) for double hull oil tankers that have collided with different types of ships. The methodology used to perform the QRA is based on the International Maritime Organisations' (IMO) definition of a Formal Safety Assessment (FSA). Using probabilistic approaches, ship-ship collision scenarios are randomly selected to create a representative sample of all possible scenarios. The collision frequency is then calculated for each scenario. As this is a virtual experiment, the LS-DYNA nonlinear finite element method (NLFEM) is used to predict the structural consequences of each scenario selected. In addition, the environmental consequences are estimated by calculating the size of each scenario's oil spill. To assess the economic consequences, the property and environmental damages are calculated in terms of monetary units. The total risk is then calculated as the sum of the resultant structural and environmental damages. Exceedance curves are established that can be used to define the collision design loads in association with various design criteria.

scholarly journals Quantitative risk assessment of Bacillus cereus in pasteurised milk produced in the Slovak Republic

2014 ◽  
Vol 32 (No. 2) ◽  
pp. 122-131 ◽  
Author(s):  
P. Ačai ◽  
Ľ. Valík ◽  
D. Liptáková
Keyword(s):  
Risk Assessment ◽  
Bacillus Cereus ◽  
Exposure Assessment ◽  
Dose Response ◽  
Slovak Republic ◽  
Reporting Rate ◽  
Assessment Model ◽  
Quantitative Risk Assessment ◽  
Milk Consumption ◽  
Using Data

Quantitative risk assessment of Bacillus cereus using data from pasteurised milk produced in Slovakia was performed. Monte Carlo simulations were used for probability calculation of B. cereus density at the time of pasteurised milk consumption for several different scenarios. The results of the general case exposure assessment indicated that almost 14% of cartons can contain &gt; 10<sup>4</sup> CFU/ml of B. cereus at the time of pasteurised milk consumption. Despite the absence of a generally applicable dose-response relationship that limits a full risk assessment, the probability of intoxication per serving and the estimated number of cases in the population were calculated for the general exposure assessment scenario using an exponential dose-response model based on Slovak data. The mean number of annual cases provided by the risk assessment model for pasteurised milk produced in Slovakia was 0.054/100 000 population. In comparison, the overall reporting rate of the outbreaks in the EU in which B. cereus toxins were the causative agent was 0.02/100 000 population in 2010. Our assessment is in accordance with a generally accepted fact that reporting data for alimentary intoxication are underestimated, mostly due to the short duration of the illness. &nbsp;

scholarly journals ERA Acute – Extending an Environmental Risk Assessment Model to the Marginal Ice Zone

2021 ◽  
Vol 2021 (1) ◽  
Author(s):  
Cathrine Stephansen ◽  
Odd Willy Brude ◽  
Anders Bjørgesæter ◽  
Ute Brönner ◽  
Tonje Rogstad Waterloo ◽  
...  
Keyword(s):  
Risk Assessment ◽  
Environmental Risk ◽  
Environmental Risk Assessment ◽  
Oil Spills ◽  
Software Tool ◽  
Assessment Model ◽  
High Temporal Resolution ◽  
Surface Activities ◽  
Marginal Ice Zone ◽  
Ice Floes

ERA Acute is a globally applicable method and software tool for environmental risk assessment (ERA) of acute oil spills (Stephansen et. al, 2017a and 2017b; Libre et al, 2018), and is to be implemented as the new industry standard ERA methodology on the Norwegian Continental Shelf (NCS). This paper describes the proposed adaptation and further development of the established ERA Acute method to enhance the functionality for ERA of acute oil spills in the Marginal Ice Zone (MIZ). Due to the highly dynamic nature of the MIZ, the pilot ERA Acute MIZ proposes to use high temporal resolution data on ice concentrations and presence of Valued Ecosystem Components (VECs) in newly developed functions to calculate impacts in the MIZ. Based on literature and preliminary sensitivity tests; parameter values and risk functions have been proposed for the MIZ (ice concentrations in intervals between 10–80 %). The functions reflect that presence of ice reduces the available space for surface activities; foraging, diving, entering and exiting the water and concentrates the oil in the same space between ice floes. These functions will now be further revised, tested and implemented in a software tool. This paper presents the proposed ERA Acute MIZ methodology.

scholarly journals DOUBLE HULL OIL TANKERS—HOW EFFECTIVE ARE THEY?

1993 ◽  
Vol 1993 (1) ◽  
pp. 745-751
Author(s):  
Virgil F. Keith
Keyword(s):  
Control Systems ◽  
Oil Spill ◽  
Structural Damage ◽  
Oil Spills ◽  
State Of The Art ◽  
North Slope ◽  
First Line ◽  
Safety Measures ◽  
Oil Tankers ◽  
Double Hull

ABSTRACT The groundings of the Exxon Valdez on Bligh Reef in Prince William Sound, spilling more than 10 million gallons of Alaska North Slope crude, and the American Trader off Huntington Beach, spilling almost 400,000 gallons of Alaska North Slope crude, suggest that the construction of oil tankers be re-examined with respect to a design which could reduce both the number and magnitude of oil spills. This paper discusses state-of-the-art tanker technology with respect to spill prevention, effectiveness, and cost. The design features include double hulls, centralized bunker tankers, vacuum-retaining valves, cargo control systems, auxiliary thrusters, electronic charting, and the retransmission of the ship's position. Double hulls provide the highest probability of surviving damage, either from a collision or grounding, with no loss of cargo. Use of double hulls can reduce oil spill incidence by 90 percent in grounding situations and by 75 percent in collisions. The oil spill from the American Trader could have been completely avoided by double hull construction. The arrangement provides spaces below the cargo tanks and on the vessel's sides solely for the carriage of ballast water when the tanker is in ballast condition. These tanks are empty when the tanker is loaded and then also act as the first line of defense in the event of structural damage to the cargo tanks. Tanker design is integrated with port safety measures, including vessel monitoring systems, in this total spill prevention analysis. All aspects of the tanker transportation system are considered.

A COMPARATIVE RISK ASSESSMENT TECHNIQUE FOR TANKER OIL SPILLS

1979 ◽  
Vol 1979 (1) ◽  
pp. 37-43
Author(s):  
Halûk Özkaynak ◽  
Brian L. Murphy ◽  
Joel J. Watson
Keyword(s):  
Risk Assessment ◽  
Oil Spill ◽  
Oil Spills ◽  
Assessment Model ◽  
Traffic Density ◽  
Vessel Size ◽  
Oil Transport ◽  
Fleet Composition ◽  
The Matrix ◽  
Comparative Risk

ABSTRACT The tanker oil spill risk assessment model (TRAM) allows a user to investigate the way in which oil spill probabilities, and amounts spilled, vary with such factors as fleet composition, navigational aids, or particular properties of the route. Such a comparison of alternatives is generally required for an environmental impact statement. TRAM operates through multiplication of a series of matrices: P, Q, R, and S. The rows and columns of all matrices are parameterized by accident type (such as collision or grounding) and location (such as at a pier, or in a harbor). The probability of an accident (P) and of a spill following an accident (Q) are based on world tanker fleet data. The matrix S expresses the conditional probability that if there is a spill, the vessel will be a total loss. This enables catastrophic spills in which spill size can be related to vessel size to be distinguished from minor spills in which vessel size is generally not a factor. The matrix R contains most of the unique features of the model. It accounts for vessel and route-specific features that reasonably may be expected to alter the world tanker fleet data. Examples are given from the literature for the elements of R corresponding to: fleet composition (domestic/foreign carrier); navigation aids such as vessel traffic system; vessel age, and construction (double hull, inerting system, segregated ballast, etc.); and various features of the tanker route, such as channel width and traffic density, based on Macduff's causation probability formalism. The practical usage of the model is demonstrated by applying it to a hypothetical project involving tanker oil transportation. The extension of this analysis technique to other forms of risk analysis studies (including operations other than oil transport) is also discussed.

A Maritime Oil Spill Risk Assessment Model

2001 ◽  
Vol 2001 (1) ◽  
pp. 235-240 ◽  
Author(s):  
Lalit Yudhbir ◽  
Eleftherios Iakovou
Keyword(s):  
Risk Assessment ◽  
Oil Spill ◽  
Oil Spills ◽  
Transportation Network ◽  
Coast Guard ◽  
Maritime Transportation ◽  
Assessment Model ◽  
Risk Assessment Model ◽  
Case Scenario ◽  
Oil Transportation

ABSTRACT Mantime oil transportation decision-making models that integrate with oil spill risk assessment methodologies are scarce. Recently, first time quantitative efforts have been developed for the maritime transportation of petroleum products. However, there still exists a serious gap in the literature concerning risk assessment models that provide a rather significant input to any maritime oil transportation model, namely the estimation and assignment of risk costs to the links of such a network. The authors first present a critical review of oil spill risk assessment efforts found in the literature and then the development of a novel oil spill risk assessment model. The goal of this risk assessment methodology is twofold: first, to determine and assign risk costs to the links of a maritime transportation network, and second, to provide insights into contributors that lead to spills. Such insights may further lead to guidelines for the prevention of future incidents leading to spills. A federal regulatory agency (such as the U.S. Coast Guard) and/or a commercial shipper may use the identification of the dominant contributors to oil spills to evaluate the merits of alternative regulatory and shipping policies that could lead to improved safety performance of the marine system. The authors finally exhibit the usage of the proposed methodology on a real case scenario.

An ecological risk assessment model for Arctic oil spills from a subsea pipeline

2018 ◽  
Vol 135 ◽  
pp. 1117-1127 ◽  
Author(s):  
Ehsan Arzaghi ◽  
Rouzbeh Abbassi ◽  
Vikram Garaniya ◽  
Jonathan Binns ◽  
Faisal Khan
Keyword(s):  
Risk Assessment ◽  
Ecological Risk ◽  
Ecological Risk Assessment ◽  
Oil Spills ◽  
Assessment Model ◽  
Risk Assessment Model ◽  
Subsea Pipeline
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