Enhancement of occupational health and safety requirements in chemical tanker operations: The case of cargo explosion

Operational precautions for chemical tankers are vitally important in reducing the potential threat to shipboard crew by products carried. This paper enhances the International Safety Management (ISM) code in compliance with Occupational Health and Safety Management Systems (OHSAS 18001:2007) requirements in respect to operational constraints related to chemical tankers. As research methodology, Fuzzy Axiomatic Design (FAD) and Analytic Hierarchy Process (AHP) are referred to redesign the extended ISM code procedure, which identifies key points for occupational accident prevention on board chemical tankers. To illustrate the expected benefits of an extended ISM code procedure, the principle root causes of chemical tanker explosion are also discussed. In particular, the main results of the case study highlight the urgent need to ensure the competency of shipboard personnel and their familiarization with the characteristics of chemical cargos under differing circumstances. The outcomes set out in this paper contribute to regulatory compliance and to the management of occupational health and safety requirements on board chemical tankers.     

铝土矿海上运输安全风险研究综述

基于易流态化固体散装货物的定义,将具有类似特性的铝土矿作为研究对象,通过梳理易流态化固体散装货物海上运输风险的研究现状,评述2类研究方法——船舶与海洋工程方法和系统安全工程方法,探讨货物含水量及其本质物理属性作为热点的研究脉络,研讨作为承载工具的船舶适装性及其稳性特征,论述自然环境对船舶和货物的影响,探究船舶营运的全过程风险,归纳了有关流态化机理的研究结论。铝土矿安全运输的研究和实践表明国际航运业对铝土矿船运时的流态化机理尚不清晰、研究方法不足、应对措施不强,展望未来应开展以下工作:健全铝土矿海上运输监管机制、强化铝土矿与散货船的耦合机理研究、开展铝土矿运输船舶营运的过程风险研究、推进铝土矿海运安全风险管理的智能化。     

Application of CREAM human reliability model to cargo loading process of LPG tankers

The storage and handling processes of liquefied petroleum gas (LPG) constitutes a complex operational environment in the maritime mode of transportation. The LPG cargo is carried by specially designed ships called LPG tankers. The LPG cargo loading and discharging operations have always potential hazards. Thus, the crew on-board LPG tankers should be fully aware of operational risks during the cargo handling process, which includes various critical tasks such as drying, inerting, gassing-up, cooling, and reliquefaction. During these stages, human reliability (operation without failure) plays a crucial role in sustainable transportation of cargo. Human reliability analysis (HRA), related to various parameters such as the human factor, technology, and ergonomics, is always a critical consideration as regards maritime safety and environment. The main focus of the research is to systematically predict human error potentials for designated tasks and to determine the required safety control levels on-board LPG ships. The paper adopted CREAM (Cognitive reliability and error analysis method) basic and extended versions in order to assess human reliability along with the cargo loading process on-board LPG tanker ships. Specifically, the model is demonstrated with an operational case study. Consequently, the research provides should contribute to maritime safety at sea and prevention of human injury and loss of life on-board LPG ship.     

A fuzzy DEMATEL method to evaluate critical operational hazards during gas freeing process in crude oil tankers

Gas freeing process in crude oil tanker ships is widely recognized one of the most hazardous aspects of shipboard operations. Although the process provides practical benefits to ship by removing the explosive or poisonous gases from the cargo tanks and raising the oxygen level up to 21 percent, the consequences of failure may cause serious damage to human health, marine environment and cargo. Therefore, the crew exercise utmost care and become aware of the potential hazards in gas freeing process. In this context, this paper provides a fuzzy DEMATEL (Decision Making Trial and Evaluation Laboratory) method to evaluate critical operational hazards in gas freeing process. While the DEMATEL method enables to identify and analyse the potential hazards of gas freeing process with respect to causal–effect relation diagram, fuzzy sets deal with the uncertainty in decision-making and human judgements through the DEMATEL. Thus, the hybrid approach provides smart solution for safety practitioners to prevent critical hazards in gas freeing process. The results of the research will contribute to maritime safety at sea and prevention of environment pollution as well as loss of life on-board crude oil tankers ships.     

An Analysis of Work Environments and Operations in Hot and Humid Areas

Crews on tankers traveling and hauling cargo on the lower reaches of the Mississippi River during the hot and humid (H&H) summer season face various occupational safety and ergonomics problems. Evaluation of medical data reveals that a large number of the crewmembers experience job related injuries, diseases, disorders, and exhaustion as a result of adverse environmental conditions (National Institute for Occupational Safety and Health [NIOSH], 1993). The accidents and injuries that occurred were characterized and then analysis was used to recommend constructive remedies and solutions. The results were also used to design and develop better work environments on the tankers and in the general industry. In H&H conditions, the body’s chemical reactions constantly change in order to maintain the best possible reaction to changing environments. This chemical reaction increases blood flow to the skin through sweating. Body metabolism stabilizes body temperature through muscular work and convection, evaporation and radiation remove heat.     

Allocation of performance shaping factors in the risk assessment of an offshore installation

Offshore oil production is one of the most important human productive activities. There are many risks associated with the process of constructing a subsea well, pumping oil to the platform, and transporting it to refineries via underwater pipes or oil tankers. All actions performed by workers in those operations are influenced by specific working conditions, involving the use of complex systems. Contextual factors such as high noise, low and high temperatures and hazardous chemicals are considered to be contributors to unsafe human actions in accident analysis and also give a basis for assessing human factors in safety analysis. Some failure modes are particularly dangerous and can result in severe accidents and damage to humans, the environment and material assets. Fires and explosions on oil rigs are some of the most devastating types of offshore accidents and can result in long-term consequences. The most typical root causes related to accidents include equipment failure, human error, environmental factors, work organization, training and, communication, among others. The principal objective of this study is to propose a methodological framework to identify the factors that affect the performance of operators of an offshore unit for oil processing and treatment. In this phase, an ergonomics approach based on operators' work analysis is used as a supporting tool. After identification of factors that affect the performance of operators, a decision-making model based on AHP (analytic hierarchy process) is applied to rank and weight the principal performance shaping factors (PSFs) that influence safe operations. The next step involves the use of the SHELLO model to group the main PSFs in elements named software, hardware, environment, liveware and organization. In the last phase, a relevant accident that occurred aboard a floating production storage and offloading (FPSO) vessel is analyzed. The allocation process of the factors that affect the operator's performance in risk assessment was developed through fuzzy logic and the ISO 17776 standard.     

Fire and explosion at mutual major hazard installations: review of a case history

In industry, it is common that there are independent but related major hazard installations which compliment each other. The link between the major hazard organizations is an interface between the installations. This interface is a critical area for the mutual major hazard installations. Examples of such organizations are chemical cargo ships and their terminal storage yard, the supply vessels and platforms, floating storage tanks at offshore areas and oil tankers, two offshore platforms tied together etc. This paper summarizes the major accident at M. T. Choon Hong III Ship and Tiram Kimia Sdn. Bhd. (TKSB), and also discusses the causes which led to this major accident. It was found that the lack of integrity is the main cause behind the escalation of the fire and explosion at the Choon Hong III Ship and the TKSB. It was noted that the disaster which involved mutual major hazard installation was preceded by two incubation periods.     

作业条件危险性评价法在深水钻完井作业评价中的应用研究

深水钻完井作业长期暴露于危险环境中,被普遍认为是高危作业。同时深水事故的发生给人类带来深刻的教训,例如墨西哥漏油事件造成恶劣的海洋环境污染,有必要提高钻完井作业的安全性。由于深水钻完井作业复杂,其危险性复杂多样,需从作业单元入手详细分析其危险性。本文采用作业条件危险性评价法（LEC）对深水钻完井作业进行危险性评价。首先,辨识危险有害因素;其次,在对作业条件危险性评价法进行改进的基础上分析深水油气田钻完井作业火灾爆炸危险性。分析结果表明改进后的作业条件危险性评价法能够更准确地确定危险等级,为对深水钻完井作业其它危险因素评价提供了参考。     

Experimental study of the VOC emitted from crude oil tankers

Light hydrocarbons vaporize to the space between crude oil interface and roof of the storage tank during loading of crude oil tankers in marine oil terminals. When crude oil is loaded to the tank, these hydrocarbons are vented into the atmosphere which is considered as a main source of emission of volatile organic compounds (VOCs) in oil terminals. VOCs emitted from the crude oil not only create severe air pollution problems but also a considerable amount of valuable hydrocarbons are wasted to the atmosphere. On the other hand, VOCs are flammable which create major safety hazards to the loading process. Therefore, the oil industry has largely focused on control of VOCs. In this research, an experimental study was conducted to characterize VOCs emitted from storage tanks of crude oil in a large-scale oil export terminal. Using the industrial data and simple mathematical tools, effect of different parameters on the composition of emitted gases was investigated. Furthermore, an experimental procedure is proposed to assess the potential of a crude oil absorption process for recovering emitted gases. Experimental results showed that the crude oil absorption process can be adapted to the situation of considered marine terminal for recovering this vent stream of emitted gases. This work can help plant engineers to decide on an appropriate strategy to control VOCs.     

Risk analysis of deepwater drilling operations using Bayesian network

Deepwater drilling is one of the high-risk operations in the oil and gas sector due to large uncertainties and extreme operating conditions. In the last few decades Managed Pressure Drilling Operations (MPD) and Underbalanced Drilling (UBD) have become increasingly used as alternatives to conventional drilling operations such as Overbalanced Drilling (OVD) technology. These newer techniques provide several advantages however the blowout risk during these operations is still not fully understood. Blowout is regarded as one of the most catastrophic events in offshore drilling operations; therefore implementation and maintenance of safety measures is essential to maintain risk below the acceptance criteria. This study is aimed at applying the Bayesian Network (BN) to conduct a dynamic safety analysis of deepwater MPD and UBD operations. It investigates different risk factors associated with MPD and UBD technologies, which could lead to a blowout accident. Blowout accident scenarios are investigated and the BNs are developed for MPD and UBD technologies in order to predict the probability of blowout occurrence. The main objective of this paper is to understand MPD and UBD technologies, to identify hazardous events during MPD and UBD operations, to perform failure analysis (modelling) of blowout events and to evaluate plus compare risk. Importance factor analysis in drilling operations is performed to assess contribution of each root cause to the potential accident; the results show that UBD has a higher occurrence probability of kick and blowout compared to MPD technology. The Rotating Control Devices (RCD) failure in MPD technology and increase in flow-through annulus in UBD technology are the most critical situations for kick and blowout.     

化工园区地震Na-Tech事件快速风险评估方法

为有效评估地震灾害与化工园区工业事故的耦合风险,在分析地震灾害作用于化工园区致灾特征的基础上,理清化工园区的主要承灾体类型,辨识出地震破坏承灾体单元后引发的火灾、爆炸、中毒等工业事故的主要影响因素,采用层次分析法(AHP),提出综合考虑地震灾害与工业事故耦合作用的Na-Tech事件快速风险评估方法。该方法以化工园区企业为评估单位,根据评估结果划定企业Na-Tech事件风险等级,并将此方法应用于某化工园区企业的风险评估。结果表明:该方法可操作性强,计算所需数据量小,且能有效反映地震Na-Tech事件风险特点。     

感潮港口多时段船舶引航过程风险仿真模型

为研究感潮港口船舶在不同潮时进港靠泊的引航过程风险演化规律,以优化泊位利用率和提高港口的生产效率,有必要进行多时段船舶引航过程风险的动态仿真。在对船舶引航任务场景和历史数据进行分析的基础上,采取HHM方法构建船舶引航过程的关键风险指标体系,采用AHP-CRITIC方法结合风险因素的主客观分布特点获取不同引航阶段中各指标权重,最后利用不确定人工智能云模型进行多时段船舶引航过程风险的建模仿真。通过某集装箱船的感潮水域引航过程场景分析,融合采样点的客观数据和专家知识对6个靠泊窗口期船舶引航过程风险进行动态仿真。结果表明:船舶引航过程风险演化整体呈U形曲线模式,相比正常航行阶段风险值,船舶引航初始和靠泊阶段风险值高60%左右;感潮港口6个窗口期的船舶引航过程风险略有差异,潮高、潮流对船舶交通流和起锚、靠泊作业安全影响明显。     

Quantitative risk assessment model of hazardous chemicals leakage and application

The hazardous chemical accidents remain a matter of major concern. However, there is a dearth of practical measures about the emergency management of hazardous chemicals leakage. Therefore, in order to provide more accurate management plan, quantitative risk assessment has become a critical issue in chemical industry. The main aim of this study is to quantify the risk of hazardous chemicals leakage, and take precautions against the accidents. In this study, a Fire-Explosion-Poisoning Quantitative Probability Model (FEPQPM) has been established. The paper introduced the probability analysis methods to analyze derivative accidents caused by hazardous chemicals leakage, established quantitative risk assessment models, and made acceptable risk level analysis. This model has been applied to quantitatively assess an enterprise’s storage tank at Changshou Chemical Industrial Distripark (CID) in Chongqing, China. Evaluation results are in line with the actual situation of the CID. It is shown that the probability of poisoning is very large, causing more economic loss than the other two types of accidents, and death toll of leakage accident increases over time, resulting in greater economic losses. The risk level of leakage accident involving poisoning is unacceptable.     

WBS-RBS与AHP方法在土建工程施工安全风险评估中的应用

结合土建工程施工安全风险管理的特点,提出了WBS-RBS与AHP相结合的土建工程施工安全风险评估方法,把评估过程分为工程项目资料调研、风险辨识、风险衡量和风险度计算4个步骤,并详细介绍了WBS-RBS风险辨识方法、专家调查风险衡量方法和AHP风险度计算方法在土建工程施工安全风险评估中的应用。WBS-RBS与AHP相结合的土建工程施工安全风险评估方法在系统分析计算的基础上,能够全面的辨识土建工程项目施工安全的典型风险和计算总的风险度,为工程项目的施工安全风险评价提供了一个可行的方法和为有效防范风险奠定了基础。     

Risk-based maintenance policy selection using AHP and goal programming

Maintenance policy selection is a multiple criteria decision making. The criteria often considered are cost and reliability of maintenance. There has been a growing interest in using risk of accidents as a criterion for maintenance selection. This paper presents an approach of maintenance selection based on risk of equipment failure and cost of maintenance. Analytic hierarchy process (AHP) and goal programming (GP) are used for maintenance policy selection. A case study in a benzene extraction unit of a chemical plant was done. The AHP results show that considering risk as a criterion, condition based maintenance (CBM) is a preferred policy over time-based maintenance (TBM) as CBM has better risk reduction capability than TBM. Similarly, considering cost as a criterion, corrective maintenance (CM) is preferred. However, considering both risk and cost as multiple criteria, the AHP–GP results show that CBM is a preferred approach for high-risk equipment and CM for low risk equipment.     

基于模糊数学钻井井喷概率计算模型研究

针对目前钻井井喷风险主要是单因素定量分析或者多因素的事故树定性分析,不够全面,定量性差等问题,基于层次分析法和模糊综合评价法,建立了钻井井喷的多因素定性定量分析方法.通过层次分析法对影响钻井井喷的地质、井型井别、钻井参数和人员资质等因素进行分析,根据各因素在钻井井喷中作用大小,采用“1-9”标度法确定各因素的权重.基于模糊数学理论,采用不同的隶属度函数确定方法,建立了适合不同因素的隶属度函数,在此基础上形成了钻井井喷概率计算方法.通过实例计算表明,此模型可以预测钻井井喷的概率,符合现场实际情况,对钻井过程中预防井喷具有一定的指导借鉴作用.     

在役化工装置安全评价指标体系构建方法的探讨

分析当前在役化工装置安全评价指标体系建立中存在的问题,提出"从风险分析到措施"的建立安全现状评价指标体系的新思路。探讨综合应用事故树分析法、层次分析法等方法并建立安全评价指标体系及确定指标权重的具体方法,使评价指标的建立及指标权重的确定更具有科学性。通过具体的化工装置安全评价指标建立及其权重确定的过程,介绍该方法的具体应用,不仅适用于在役化工装置的安全评价,也适用于其他系统的安全现状评价。该评价指标体系既能查找出装置中存在的具体安全隐患,也能给出装置总体安全性评价结论。     

基于改进层次分析法的城中村火灾风险评估及防控对策研究

为更好的预防与控制城中村火灾风险,本文将事故树、层次分析法、模糊综合评价相结合,通过FTA建立AHP模型,从防火能力、灭火能力、安全疏散能力、安全管理水平4个维度出发构建了城中村火灾风险评估指标体系,并计算了各评价指标权重,通过实例研究证明,该方法能够较好的分析评价城中村火灾风险安全等级,最后提出相对应的对策与建议,有利于城中村火灾风险的预防与控制,为提高城中村火灾消防安全管理水平奠定了理论基础。     

Loss prevention in turnaround maintenance projects by selecting contractors based on safety criteria using the analytic hierarchy process (AHP)

Turnaround maintenance (TAM) is a usual plant shutdown that is done by process industries to perform asset inspections, repairs, and overhauls. TAM engineering projects are needed on a periodic basis to optimize a plant's performance. Process industrial plants usually don't have enough in-house manpower to carry out needed TAM jobs; it is not uncommon for a process industrial plant to outsource its TAM manpower supply to external contractors. This will create a peculiar management challenge regarding how to assure orientation of safety practices for the newly hired labor. Although accidents during process plant shutdowns may have severe consequences, the safety management systems in place for many companies only cover normal operations and few explicitly address TAM projects. Usually, contractors are evaluated from a safety perspective after handling the project by monitoring safety indicators such as number of injuries, incidents, etc. This paper emphasizes safety attributes to be included in selecting contractors at the bidding stage to assure loss prevention and better safety orientation during TAM implementation. The paper starts with reviewing TAM literature and defining main needed safety attributes to prequalify contractors. It develops an analytic hierarchy process (AHP) model that is applied to rank TAM contractors' selection. A case study is presented for a petrochemical plant in Saudi Arabia to demonstrate the AHP model.     

基于海洋环境要素的动态航行风险评估*

为得到精确动态航行评估结果,将多准则决策方法与GIS风险制图技术相结合,以5种海洋环境要素（风场、洋流、海浪、海温和海底地形）作为评估因子,通过数据时空插值法和层次分析法（AHP,Analytic Hierarchy Process）确定评估因子权重,提出权重优化算法改进权重值,进而得到最优动态航行风险评估结果。结果表明:动态航行风险评估结果能够直观展示海域航行风险空间分布和变化趋势,评估具有实时性和连续性,可以为海域恶劣海况提供足够预警能力。