Grounding Accidents Research Articles

Analysis of Grounding Accidents in Small Fishing Vessels and Suggestions to Reduce Them

Analysis of Grounding Accidents in Small Fishing Vessels and Suggestions to Reduce Them

A methodology to assess the causation relationship of seafarers’ unsafe acts for ship grounding accidents based on Bayesian SEM

Unsafe acts have been recognized as the substantial factors leading to maritime accidents. An obstacle to analyzing seafarers' unsafe acts involved in maritime accidents is the lack of data. Bayesian approach in structural equation modelling (SEM) estimation has attracted extensive attentions across other fields, due to its advantages that can handle complicated models and small sample size. Therefore, this study proposes an innovative methodology to address the multifactor risk coupling and causation involved in seafarers' unsafe act contributing to ship grounding accidents. Based on the principle of Bayesian SEM, the advantages of Grounded theory and Human Factors Analysis and Classification System (HFACS) are integrated into this methodology. Specifically, Grounded theory and HFACS model are applied to identify and structure seafarers' unsafe acts and their contributory factors, facilitating the development of the conceptual model. Then, by employing Bayesian SEM, the causation paths and effects of seafarers' unsafe acts are examined. The results reveal that organizational influences play a significant role in the causation mechanism of seafarers' unsafe acts, and preconditions for unsafe acts are the only variables that exert direct impact on unsafe acts. Moreover, unsafe supervision and preconditions for unsafe acts are served as intermediate factors affecting seafarers' unsafe acts. In addition, this results indicate the feasibility of Bayesian SEM in analyzing seafarers’ unsafe acts.

Automated Motion Heatmap Generation for Bridge Navigation Watch Monitoring System

Abstract Most ship collisions and grounding accidents are due to errors made by watchkeeping personnel (WP) on the bridge. International Maritime Organization (IMO) adopts the resolution on the Bridge Navigation Watch Alarm System (BNWAS) detecting operator disability to avert these accidents. The defined system in the resolution is very basic and vulnerable to abuse. There is a need for a more advanced system of monitoring the behaviour of WP to mitigate watchkeeping errors. In this research, a Bridge Navigation Watch Monitoring System (BNWMS) is suggested to achieve this task. Architecture is proposed to train a model for BNWMS. The literature reveals that vision-based sensors can produce relevant input data required for model training. 2D body poses belonging to the same person are estimated from multiple camera views by using a deep learning-based pose estimation algorithm. Estimated 2D poses are projected into 3D space with a maximum 8 mm error by utilising multiple view computer vision techniques. Finally, the obtained 3D poses are plotted on a bird’s-eye view bridge plan to calculate a heatmap of body motions capturing temporal, as well as spatial, information. The results show that motion heatmaps present significant information about the behaviour of WP within a defined time interval. This automated motion heatmap generation is a novel approach that provides input data for the suggested BNWMS.

A methodology to quantify the risk propagation of hazardous events for ship grounding accidents based on directed CN

An innovative methodology is proposed to address the coupling and correlation involved in the hazardous events contributing to ship grounding accidents. Based on the principle of a directed complex network (CN), the advantages of event tree analysis (ETA), the improved K-shell algorithm and the susceptible infected recovered (SIR) model are integrated into this methodology. The ETA is first applied to extract event chains involved in each accident report (39 reports in this study), resulting in the development of a directed CN, which is analysed from two perspectives: criticality calculation with the static application of the improved K-shell decomposition algorithm and sensitivity analysis by simulating SIR model. The risk propagation capacity of each objective node is evaluated by a combination of criticality and sensitivity. The results show that the proposed methodology is applicable for evaluating the risk propagation capacity of hazardous events. The trigger events located at the beginning of event chains should not receive too much attention, while the control of contributing events is essential for accident prevention. In addition, the criticality and sensitivity of the objective node are not always consistent; therefore, the strategies defending the risk propagation process may vary according to the different classifications of hazardous events.

Probability-based extensive quantitative risk analysis: collision and grounding case studies for bulk carrier and general cargo ships

ABSTRACT In this study, the risk of collision and grounding accidents on bulk carrier and general cargo ships was investigated. A comprehensive risk analysis consisting of past accident reports, fault tree analysis (FTA) and Cut sets importance measure (CS-I) methods was carried out. The failures effective in the occurrence of collision and grounding accidents were determined by examining past accident reports. In the study, the probability for each failure was derived by using real accident data. Using FTA, various potential accident occurrence combinations/scenarios, also known as minimal cut sets (MCSs), for both accident types were obtained. In addition, prioritization was conducted for the MCSs of both types of accidents using CS-I sensitivity analyses. The faults that increase the risk of collision accidents the most were found to be interpretation failure of the Convention on the International Regulations for Preventing Collisions (COLREG) and lack of situational awareness. In addition, the top failures that lead to groundings were determined to be lack of communication in bridge resource management (BRM), fatigue/sleeplessness and inappropriate voyage plan. Recommendations are made for eliminating potential risk factors, preventing the recurrence of such accidents and establishing safer maritime transport.

RISK ANALYSIS OF GROUNDING ACCIDENTS BY MAPPING A FAULT TREE INTO A BAYESIAN NETWORK

Groundings, which account for approximately one-third of ship accidents, are classified as very serious with tragic consequences. Therefore, identifying the factors causing groundings is essential to reduce their effects and to prevent recurrence. Thus, the principal purpose of this study is to analyse the risks of grounding accidents using an integrated model. First, a fault tree analysis (FTA) was applied to create a risk hierarchy that defines the level of relationship among factors; and a Bayesian network (BN) analysis was conducted to evaluate the level of their effect on groundings. The study found that of the 34 factors related to the safety of navigation, E10/violation of COLREG Rule-5 (look-out), E9/improper use of ECDIS, and E8/improper use of radar significantly effect groundings. The findings also indicate that maintaining a safe navigation watch is crucial to prevent future accidents. This study makes a significant contribution to the relevant literature as one of the few pieces of research using the combined FTA-BN as a dynamic risk assessment methodology for analysis of grounding accidents. We recommend that further research use other risk assessment methods that consider different ship types for a better comparison.

The effect of nonconformities encountered in the use of technology on the occurrence of collision, contact and grounding accidents

Technology and its innovative applications make life easier and reduce the workload on seafarers. Today's ship bridges have much more modern and integrated navigation systems than before, and the ship's handling and management have become much easier. However, nonconformities encountered in the use of technological devices may cause accidents. In this study, the effect of human factor related errors associated with the use of the bridge's electronic navigational devices on grounding and collision-contact accidents was investigated. Nonconformities obtained from 175 collision-contact and 115 grounding accident reports were qualitatively analysed by means of human factor analysis and a classification system. Afterwards, relationships between nonconformities and their probabilities were evaluated quantitatively via a Bayesian network method. As a result of the study, the accident network was revealed. This accident network summarizes how operating errors in the use of technological equipment cause accidents. Recommendations on the prevention of accidents caused by operating errors associated with the use of new technologies are finally given.

Application of the HFACS-PV approach for identification of human and organizational factors (HOFs) influencing marine accidents

Shipping is one of the leading modes of transport that has dominated the world economy from past to present. The effectiveness and efficiency of maritime trade is closely related to maritime safety. Providing quality maritime safety is a fundamental requirement for environmentally friendly, sustainable, safe and efficient global trade. Therefore, maritime safety and human factors are frequently studied topics in literature. However, the fact that the human element has a complex socio-technical structure makes it difficult to fully analyse human factors in accidents. That is one of the biggest challenges in preventing and mitigating accidents. This research aims to demonstrate the feasibility of the modified Human Factor Analysis and Classification System for Passenger Vessel collisions (HFACS-PV) for other types of accidents. 51 grounding accidents that occurred in passenger vessels between 1991 and 2017 were analysed by using the HFACS-PV structure. The results show that the HFACS-PV structure created for passenger vessel accidents is compatible with contact, grounding and sinking accidents as well as collisions. Thus, the HFACS-PV structure allows for coherent analysis of marine accidents. Owing to the flexibility of HFACS, it is also possible to combine it with other analytical methods to conduct both qualitative and quantitative analysis.

Analysis of structural crashworthiness of double-hull ships in collision and grounding

A conceptual design framework for collision and grounding analysis is proposed to evaluate the crashworthiness of double-hull structures. This work attempts to simplify the input parameters needed for the analysis, which can be considered as a step towards a design-oriented procedure against collision and grounding. Four typical collision and grounding scenarios are considered: (1) side structure struck by a bulbous bow, (2) side structure struck by a straight bow, (3) bottom raking, (4) bottom stranding. The analyses of these scenarios are based on statistical data of striking ship dimensions, velocities, collision angles and locations, as well as seabed shapes and sizes, grounding depth and location. The evaluation of the damage extent considers the 50- and 90-percentile values from the statistics of collision and grounding accidents. The external dynamics and internal mechanics are combined to analyse systematically the ship structural damage and energy absorption under accidental loadings.

Ultimate strength of ship hull girder with grounding damage

ABSTRACT The paper presents a method for the assessment of residual strength of a ship hull damaged in a grounding accident. The strength assessment is based on a coupled beam (CB) method that allows time-efficient analysis. As a case study the method is applied to a double hull tanker. Three grounding damages are defined based on IACS guidelines and with a dedicated grounding assessment tool. The CB method is based on an assumption that global bending response of a ship can be estimated with the help of beams coupled to each other by distributed springs. To include the damage opening in the residual strength assessment, the structural elements in the damaged region are excluded by reducing their elastic modulus. For the validation of the CB method, the residual strength is also evaluated with non-linear finite element method. Good correlation between the methods is reported.

Correlation Between Strong Wind and Leisure Craft Grounding in Croatian Waters

This paper examines the correlation between strong wind and the frequency of small leisure craft grounding by analysing the available data on maritime accidents in the Adriatic. The primary goal of this study was to verify the hypothesis from prior research that strong wind is the prime cause of groundings in certain areas of the Adriatic. Contrary to the conclusions of the prior research, the new analysis indicates a far more uniform spatial distribution of wind-caused grounding accidents across all the examined areas of Croatian Adriatic waters. Furthermore, the analysis indicates that most grounding accidents occur in light wind conditions, suggesting that groundings can predominantly be attributed to factors other than strong wind. Several important drawbacks of the analysis stemming from the lack of accurate data on accidents in Croatian waters are discussed and suggestions given for the improved collection thereof that would greatly contribute to the future research on this topic. The inability to determine the exact causes of particular accidents from available data makes it impossible to accurately establish the number of grounding accidents caused by strong wind. In the future, more detailed statistical data could improve our understanding of the correlation between adverse weather conditions and recreational vessel accidents in the Adriatic.

Towards a probabilistic model for estimation of grounding accidents in fluctuating backwater zone of the Three Gorges Reservoir

The water level fluctuations in the upper reach of dam reservoirs may result in increasing occurrence probabilities of ship grounding accidents, which is especially prominent in the Three Gorges Reservoir. Grounding accidents may not only cause congestion of the traffic but also lead to loss of properties and pollution to the maritime environment. An analytical model incorporating Bayesian Network is proposed to estimate the occurrence likelihood of a ship being grounded in the fluctuating backwater zone. The proposed model comprehensively considers the characteristics of the ship's properties, organizational factors, hydrological conditions and human factors from a systematic perspective. Historical data collected from the Chongqing Maritime Safety Administration, together with incident reports, are used to develop a quantitative model. The developed model in this paper concludes that out of twenty-six factors, the area of the fluctuating backwater zone, the month, and water level are the predominant factors for the occurrence of grounding accidents in the Three Gorges Reservoir. The results can be used by maritime stakeholders to take mitigation measures for grounding accident reduction.

Miniature reproduction of raking tests on marine structure: Similarity technique and experiment

Substantial progress has been made in the last decades to computationally model the structural response of marine structures subjected to collision and grounding accidents. The finite element method stands out as the most reliable and robust technique within other tools for this purpose. However, there are still some complex physical aspects arduous to be modeled numerically. This work presents an experimental technique to reproduce the mechanical response and collapse mode of marine structures subjected to collision and grounding events by using miniature models built by additive manufacturing. This experimental technique relies on structural scaling and thickness distortion formulations. A raking test on a large-scale ship bottom was replicated in a 1:30 reduced scale to validate this technique. The miniature ship bottom structure was additively manufactured from stainless steel 316L considering all structural details. Flat dog-bone samples with different thicknesses were also built in the same way for mechanical characterization of the material via tensile tests and microscopy analysis of material fractures. Tensile tests showed a good consistency in stress-strain curves with a small, but noteworthy, influence of plate thickness and a large dispersion in rupture elongations. The fractured sections revealed various void formations around non-sintered metal powder. In spite of that, the structural response obtained from miniature test showed a good correspondence with the large-scale reference test when both are brought to the same dimensional scale.

Bayesian Network-Based Risk Assessment of Single-Phase Grounding Accidents of Power Transmission Lines.

With the increasing demand for electricity transmission and distribution, single-phase grounding accidents, which cause great economic losses and casualties, have occurred frequently. In this study, a Bayesian network (BN)-based risk assessment model for representing single-phase grounding accidents is proposed to examine accident evolution from causes to potential consequences. The Bayesian network of single-phase grounding accidents includes 21 nodes that take into account the influential factors of environment, management, equipment and human error. The Bow-tie method was employed to build the accident evolution path and then converted to a BN. The BN conditional probability tables are determined with reference to historical accident data and expert opinion obtained by the Delphi method. The probability of a single-phase grounding accident and its potential consequences in normal conditions and three typical accident scenarios are analyzed. We found that “Storm” is the most critical hazard of single-phase grounding, followed by “Aging” and “Icing”. This study could quantitatively evaluate the single-phase grounding accident in multi-hazard coupling scenarios and provide technical support for occupational health and safety management of power transmission lines.

Minimizing the Environmental Risk from Oil Tanker Grounding Accidents in the High North

To address the high environmental risk related to the increased oil tanker traffic in the High North, the Norwegian Coastal Administration (NCA) manages one of its vessel traffic service (VTS) centers in the town of Vardo, Norway. The fleet of tugboats, controlled by the VTS center operators, patrols the coastline to hook-up with any potential drifting oil tanker in the region of interest, before it runs ashore. Presently, the tugboats are controlled manually, which is not only challenging but less effective. In this paper, we develop two alternative binary integer programming models that give better tugboat policies in less computational time compared to previous work. Promising results with historical data illustrate great potential for optimal environmental risk reduction along the northern coast of Norway

A causative analysis on ECDIS-related grounding accidents

ABSTRACT This study introduces an assessment concerning the use of Electronic Chart Display and Information System (ECDIS) in the safe navigation of vessels by considering the case studies whether the device played a role in grounding accidents. A total 80 investigation reports of grounding accidents from 2008 to 2018 were analysed. In 22 cases, one or more findings related to ECDIS and Electronic Navigational Charts (ENC) were identified. Twenty two accidents related to ECDIS or ENCs were re-analysed with 4M Overturned Pyramid (MOP) model to determine the characteristics and causes of accidents. Causative factors that related ECDIS in the cases have been listed and explained. Results indicate that ECDIS-related procedures and lack of training have led to incorrect settings of the device, especially alarm settings. The recommendations have been arranged that ECDIS devices, which offer much considerable information for the safe navigation of ships, are able to work more efficiently.

A practical diagram to determine the residual longitudinal strength of grounded ship in Northern Sea Route

ABSTRACT In this study, a useful solution is proposed for assessing the safety of the ship’s hull damaged by grounding in Northern Sea Route (NSR) or Arctic sea. In particular, the residual ultimate longitudinal strength of grounding damaged ship can be predicted by the grounding damage index (GDI) concept. Due to the global warming effects, the Arctic glaciers have been gradually melting, and it may bring us the new North Pole routes. However, there are uncertainties on many causes that can lead to grounding accident of the commercial vessels. In this regard, residual ultimate longitudinal strength of grounding damaged commercial ship in Arctic sea is investigated. Five (5) temperatures: room temperature (RT), −20°C, −40°C, −60°C and −80°C were adopted to consider the cold temperature effect in NSR. The Panamax class oil tanker was selected for the investigation of residual ultimate longitudinal strength of grounding damaged ship. Fifty (50) reliable damage scenarios were adopted for the evaluation of structural health by utilising Residual strength versus GDI (R-D) diagram method. From this study, a modified R-D diagram is proposed which can consider grounding damage with cold temperature effect. The obtained outcome will be useful for assessing the safety of the grounded ships in Arctic sea region by measuring the grounding damage amount and surrounding air temperature.

Crashworthiness assessment of thin-walled double bottom tanker: A variety of ship grounding incidents

This study addresses the issue of ship accidental grounding as an impact phenomenon, with the assumption that an interaction of its structure with the oceanic seabed (obstruction), idealized as rock topology, is capable of initiating a so-called hard ground scenario. This occurrence variation was considered by performing two main instances, encompassing raking and stranding, often experienced by oil/chemical tankers as thin-walled structures. In addition, a failure criterion was implemented on the structural geometry, in order to define its ultimate limit and possible damage, during interaction with the obstructions. Subsequently, the analysis results were compiled to assess structural crashworthiness as well as progressive failure of the double bottom part of the tanker, where energy criterion indicated the raking to be more destructive. Meanwhile, detailed observation of the failure sequence indicated the stranding to have successfully breached the inner bottom shell.

Modelling of the Oil Spill in M/V LADY TUNA Accident and the Evaluation of the Response Operation in Simulated Condition with PISCES II.

Oil pollution from ships is an important source of marine pollution and becomes an important problem all over the world. For this reason, every effort should be made to prevent oil spills and to remove them effectively as soon as pollution has emerged. In this respect, various computer simulations are used to get well informed about the fate of spilled oil on the seawater. In this study, the grounding accident of ship M/V Lady Tuna causing 75 tons of fuel spills into the sea on December 18, 2016, close to the coast of Cesme in Turkey, was investigated. The aim of the study is to investigate the oil spill accident and evaluate the response operation of M/V Lady Tuna. To achieve this aim, firstly the reports related to the accident were examined and the response operation was evaluated by modelling of the M/V Lady Tuna accident with PISCES II (Potential Incident Simulation, Control and Evaluation System) simulator. Within this scope, two scenarios were prepared by using PISCES II. The first scenario was created without any response resources to observe the movement direction of the oil slick after the accident. The second scenario was reconstructed with the possible response resources after the oil spill. Through simulation, it was possible to obtain the oil spill/pollution statistics; such as the recovered oil rate, the amount of stranded oil to the coast, the amount of floating oil rate, and other oil spill parameters. As a result, it was evaluated that the oil pollution in the M/V Lady Tuna accident could be responded more effectively and the pollution could be much less. It is assessed that the study will contribute to organizations involved in oil spill response operations.

Ship accident consequences and contributing factors analyses using ship accident investigation reports

Ship accident consequences, including life loss, property/cargo damage, and environment pollution, could be caused by various factors. This study aims to quantitatively analyze the association between ship accident consequences and related contributing factors based on real ship accident investigation reports. We propose a two-step research methodology. In the first step, we standardize the necessary contributing factor–related information that is extracted from the ship accident investigation reports. In the second step, three statistical analysis methods, including nonparametric statistics of Kendall’s tau coefficient, Cramér’s V analysis and Kruskal–Wallis test, are carried out to figure out the import contributing factors with respect to ship accident consequences. The proposed methodology has been assessed based on 477 ship accident reports. Some insightful findings are obtained: (1) vessel speed is the most significant factor contributing to fatality and injury of collision accidents, whereas no remarkable relationship holds for grounding accidents; (2) for collision accidents, crew number shows a strong association with injury and fatality, but it exhibits weak linkages to other consequences of ship damage, cargo damage and oil spill; and (3) the consequence of oil spill is strongly related to collision position, especially in head-on and crossing collisions.