Analysis and control of major accidents from the intermediate temporary storage of dangerous substances in marshalling yards and port areas

Probabilistic risk analysis of unit trains versus manifest trains for transporting hazardous materials

When transporting hazardous materials by rail, train types (unit train or manifest train) can influence derailment and release risks in several ways. Unit trains only experience risks on mainlines and when arriving at or departing from terminals, while manifest trains experience additional switching risks in yards. A comprehensive risk assessment methodology is needed to quantitively compare shipments with unit trains and manifest trains, considering both mainline and yard operations. To fulfill this research gap, this paper constructs event chains for line-haul risks, arrival/departure risks, and yard switching risks using various probabilistic models and finally determines expected casualties as the consequences of a potential train derailment and release incident. Five illustrative scenarios are designed to analyze the best and worst cases and compare the transportation risk differences between service options using unit trains and manifest trains. The comparison results indicate that placing all tank cars at the positions with the lowest probability of derailing and switching tank cars alone in classification yards could provide the lowest risk estimate given the same transportation demand.

Identification of cultivable bacterial strains producing biosurfactants/bioemulsifiers isolated from an Algerian oil refinery

Algerian petrochemical industrial areas are usually running spills and leakages of hydrocarbons, which constitutes a major source of toxic compounds in soil such as aromatic hydrocarbons. In this paper, samples of crude oil-polluted soil were collected from Skikda's oil refinery and were subjected to mono and polyaromatic hydrocarbons threshold assessment. Soil physicochemical parameters were determined for each sample to examine their response to pollution. Amid 34 isolated bacteria, eleven strains were selected as best Biosurfactants (Bs)/Bioemulsifiers (Be) producers and were assigned to Firmicutes and Proteobacteria phyla based on molecular identification. Phylogenetic analysis of partial 16S rDNA gene sequences allowed the construction of evolutionary trees by means of the maximum likelihood method. Accordingly, strains were similar to Bacillus spp., Priesta spp., Pseudomonas spp., Enterobacter spp. and Kosakonia spp. with more than 95% similarity. These strains could be qualified candidates for an efficient bioremediation process of severally polluted soils.

Causation analysis and governance strategy for hazardous cargo accidents at ports: Case study of Tianjin Port's hazardous cargo explosion accident

As an important part of the global shipping industry, hazardous cargo transportation at ports is concerned by countries around the world due to the great hazards and high risks during its operations. However, multiple hazardous cargo accidents have occurred at ports in recent years. The explosion accident of hazardous cargoes at Tianjin Port, China, in 2015 is a typical case. It is a topic worth in-depth study to figure out how to analyze the causation factors of such accident and propose effective governance strategies against them. This article takes the hazardous cargo explosion at Tianjin Port of China as the subject and systematically analyzes the causation factors of the accident based on the Fault Tree Analysis (FTA) method. It proposes a strategy for governing hazardous cargoes at the port. The analysis results show that the hazardous cargo explosion at the port has complicated causation factors, among which management and human factors play a predominant role in the overall accident causation structure. Other factors include environmental factors and cargo & facility factors. Finally, the corresponding safety governance strategy is proposed based on the structural relationship of various accident causation factors in the above analysis. This study can offer guidance for port enterprises to reduce hazardous cargo accidents at ports and provide an important basis for port authorities to formulate strategies on emergency management and emergency decision-making of hazardous cargo accidents at ports.

A grounded theory model for analysis of marine accidents

The purpose of this paper was to design a conceptual model for analysis of marine accidents. The model is grounded on large amounts of empirical data, i.e. the Swedish Maritime Administration database, which was thoroughly studied. This database contains marine accidents organized by ship and variable. The majority of variables are non-metric and some have never been analyzed because of the large number of values. Summary statistics were employed in the data analysis. In order to develop a conceptual model, the database variables were clustered into eleven main categories or constructs, which were organized according to their properties and connected with the path diagram of relationships. For demonstration purposes, one non-metric and five metric variables were selected, namely fatality, ship's properties (i.e. age, gross register tonnage, and length), number of people on board, and marine accidents. These were analyzed using the structural equation modeling (SEM) approach. The combined prediction power of the 'ship's properties' and 'number of people on board' independent variables accounted for 65% of the variance of the fatality. The model development was largely based on the data contained in the Swedish database. However, as this database shares a number of variables in common with other databases in the region and the world, the model presented in this paper could be applied to other datasets. The model has both theoretical and practical values. Recommendations for improvements in the database are also suggested.

Reducing the threat of in-transit derailments involving dangerous goods through effective placement along the train consist

Train derailments are important safety concerns, and they become increasingly so when dangerous goods (DG) are involved. One way to reduce the risk of DG derailments is through effective DG railway car placement along the train consist. This paper investigates the relationship between DG railway car placement and derailment for different route attributes and DG shipments. A model is presented for estimating the probability of derailment by position, based on the estimated point of derailment (POD) and the number of cars derailing. A DG placement model that considers in-transit derailment risk is shown to provide a sound scientific basis for effective DG marshalling in conventional rail hump yard operations.

Land-use planning in the vicinity of chemical sites: risk-informed decision making at a local community level

Land-use planning with respect to major accident hazards is one of the new requirements of the 'Seveso II Directive'. On top of this requirement, but also recognising the importance of the issue for the control of major accidents, the various European Member States have developed or are developing adequate procedures, approaches and criteria for the acceptability of hazards or risk. At a national level, various criteria are in use based either on 'generic distances', or on the level of consequences, or on the level of risk. At a regional and local level, however, local particularities and the presence of multiple and usually conflicting objectives - such as reduction of risk with simultaneous increase of the benefit from exploitation of land - seem to be of great importance in decision making. The paper focuses especially on the local level and it presents a methodological framework to take these conflicting objectives into account. Furthermore, it discusses the application of this methodology in an interesting case study and it demonstrates the useful insights and the substantial aid with which local planners can be provided.