The work described in this thesis is concerned with formal safety analysis methods and their application to the "design for safety" process of marine and other large Made-To- Order (MTO) products with particular reference to the incorporation of safety aspects into the design process from the initial stages. Large MTO products are complex assemblies of components for which building and testing of prototypes is not usually possible. This thesis proposes a "design for safety" methodology for large MTO products based upon the general spirit of the recommendations from recent government reports including the Cullen and Carver reports. Such a methodology, consisting of five phases, namely problem definition, risk identification, risk estimation, risk evaluation and design review, is used as the basis for the development of more scientific and objective safety analysis methods and techno-economic modelling techniques applicable to the control of major accidents of large MTO products. An analysis of the input requirements and the outcomes of the typical safety analysis methods is conducted to identify their possible inter-relationships within the "design for safety" process in order to make full use of the advantages of each method. The selection of these safety analysis methods is discussed in the context of large MTO products. Problems concerned with failure and repair data collection programmes are studied and some typical failure and repair data sources are described. In order to systematically and effectively identify and estimate risks of large MTO products, an inductive bottom-up Modified Boolean Representation Method (MBRM) is developed to directly make use of the information produced using Failure Mode, Effects and Criticality Analysis (FMECA) to identify and estimate all possible system failure events and respective causes. Such a method can be used to analyse any engineering system which is capable of being broken down into subsystems and components. The overall model and the algorithms are described and tested in association with appropriate computer software. A modified qualitative reasoning method is developed to describe the behaviour of a large complex system. Such a modelling method can be used for failure propagation analysis. The proposed qualitative modelling method is further combined with the MBRM to form a flexible mixed safety modelling methodology. In this methodology, the MBRM is used to process the information produced from the qualitative reasoning analysis at the component level to obtain a description of the total system behaviour. This methodology allows a bottom-up safety analysis approach to be taken even in those cases where it is difficult to obtain complete input-output relations for all the components of the system. Two general simulation models are developed to process the information produced using FMECA and the MBRM. Such simulation models can be used as a quantitative safety analysis tool to simulate system availability, component/subsystem failures, and the probability of occurrence of each identified system failure event. These two models are developed in an Object-Oriented Programming (OOP) environment. This thesis also presents a new safety analysis and synthesis methodology involving the use of fuzzy Set modelling and evidential reasoning, where fuzzy set modelling is used to describe each failure event and an evidential reasoning approach is then employed to synthesise the information produced to assess the safety of the whole system. This subjective reasoning methodology can be used as an alternative approach by safety analysts to carry out analysis particularly in those situations where mostly nonnumerical safety data is available or where there is a lack of information regarding distributions of variables for use in probabilistic risk studies. A techno-economic modelling methodology is also developed to determine where reasonably practicable design actions are required. The proposed methodology brings together risk and cost objectives into the decision making process for the improvement of design aspects and maintenance policies. Information produced using the safety analysis approaches developed in this thesis can be utilised to construct a technoeconomic model. Multiple Objective Decision Making (MODM) techniques are then employed to process the constructed model. The results produced can assist designers in developing good compromise designs that take into account risks, their possible consequences, maintenance cost, repair cost and design review cost. A hydraulic transmission system of an offshore pedestal crane is used to demonstrate the methodologies developed in this thesis. Finally, the results of the research project are generally summarised and the areas where further effort is seen to be required to improve the developed methodologies are outlined.

This research has arisen from recent changes in attitudes to offshore safety. To help demonstrate structural safety to the Health and Safety Executive, operators are increasingly using structural system reliability assessments. While significant developments have been achieved in this area, there are still a number of uncertainties associated with such assessments. Unresolved technical issues also introduce significant variability in the results. The aim of this project is to develop a framework for system reliability, which will set a basis for moving towards more consistent reliability assessments. An extensive review study was undertaken first to establish the state of the art in the area of structure system reliability analysis of offshore structures. Based on the findings of this study, a generic system reliability framework was developed which was then developed further for specific application to fixed offshore platforms. These initial studies identified some of the key technical issues that required further investigation. The subsequent offshore application and sensitivity study, using a representative fixed platform model, concentrated on these issues and in particular on the effects of foundation parameters on ultimate strength and their interaction with other key parameters in determining the resistance function. The effect of foundation parameters and different modelling methods on system strength and reliability of fixed offshore platforms, which has largely been neglected in the past, was also investigated. The response surface methodology was developed for system reliability assessment of offshore structures incorporating the effect of foundation reliability. The findings were then used to revise the framework and provide more comprehensive account of key steps in the process of system reliability assessment. Some guidelines on the application of the response surface technique to fixed platform assessment were developed. In addition, an initial screening tool was also proposed for assessing the level of complexity required for the resistance model of the reliability assessment. The presentation of the reliability framework provides a comprehensive account of the various steps, methods and decisions associated with system reliability analysis. The framework, which can be used in both the design and reassessment of structures, can provide a basis for moving towards more consistent reliability assessments. Recommendations on areas that require further research are also presented.

Submitted by Rosina Valeria Lanzellotti Mattiussi Teixeira (rosina.teixeira@unisantos.br) on 2018-08-21T17:53:31Z No. of bitstreams: 1 Rodrigo de Farias Julião.pdf: 2312669 bytes, checksum: cbb55dd1bc3b181dd07ac7d4d1da85ab (MD5) / Made available in DSpace on 2018-08-21T17:53:32Z (GMT). No. of bitstreams: 1 Rodrigo de Farias Julião.pdf: 2312669 bytes, checksum: cbb55dd1bc3b181dd07ac7d4d1da85ab (MD5) Previous issue date: 2018-05-03 / A presente tese tem como objeto de estudo o amparo legal da saúde do trabalhador offshore, através da análise interdisciplinar do Anexo II da Norma Regulamentadora n°30; de Convenções Internacionais da Organização Internacional do Trabalho e do Sistema da Occupational Health and Safety Assessment Series 18001:2007. O estudo aborda os tipos de plataformas, como se estrutura o trabalho offshore na Bacia de Campos (RJ); os principais acidentes no passado e como se encontram, atualmente, as condições de trabalho e segurança nas plataformas e os problemas físicos, emocionais e profissionais do trabalhador das plataformas. A tese também apresenta a atuação da Agência Nacional de Petróleo, Gás Natural e Biocombustíveis na prevenção de acidentes. Apesar de existirem normas nacionais e convenções internacionais, direta ou indiretamente, para garantir a segurança quanto ao ambiente de trabalho nas plataformas, elas não são efetivamente aplicadas pelas empresas offshores, o que se torna também um fator passível de comprometer a saúde do trabalhador e necessitar de normatização efetiva. / The purpose of this thesis is to study the legal protection of the health of offshore workers through the interdisciplinary analysis of Annex II of Regulatory Norm 30; International Conventions of the International Labor Organization and the Occupational Health and Safety Assessment Series 18001: 2007. The study addresses the types of platforms, how to structure the offshore work in the Campos Basin (RJ); the main accidents in the past and how are currently working conditions and safety platforms and the physical, emotional and professional problems of the workers of the platforms. The thesis also presents the performance of the National Agency of Petroleum, Natural Gas and Biofuels in the prevention of accidents. Although there are national norms and international conventions, either directly or indirectly, to ensure safety in the work environment on the platforms, they are not effectively enforced by offshore companies, which is also a factor that could compromise workers' health and necessitate of effective standardization.