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Title: Application of formal safety assessment for dry docking evolution
Author: Njumo, Atehnjia Denis
ISNI:       0000 0004 5924 1570
Awarding Body: Liverpool John Moores University
Current Institution: Liverpool John Moores University
Date of Award: 2016
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This research has evaluated the rules, guidelines and regulations related to docking a ship in floating-graving yards. Historical failure data analysis is carried out to identify associated components, equipment and the area of defects related to ship docking evolution problems. The current status of ship docking evolution is reviewed and possible sources which cause accidents are recognised. The major problems identified in this research are associated with risk modelling under circumstances where high levels of uncertainty exist. Following the identification of research needs, this work has developed several analytical models for the application of Formal Safety Assessment (FSA). Such models are subsequently demonstrated by their corresponding case studies with regards to application of FSA for ship docking evolution. Firstly, in this research a generic floating-graving docking model is constructed for the purpose of hazard identification and risk estimation. The hazards include various scenarios, identified from literature reviewed as the major contributors to ship docking failures. Then risk estimation is carried out utilising fault tree (FT) – FSA where there is sufficient data. Secondly, with increased lack of data, risk estimation is carried out using FT-Bayesian network (BN) where interdepencies exists amongst identified hazards. This risk estimation method is validated with the appropriate case study identified. Thirdly, fuzzy rule base and evidential reasoning approaches are used for risk estimation in terms of three risk parameters to select the major causes of component failure that can lead to pontoon deck failure in a floating dock. Possible risk control options (RCOs) are introduced, based on their effectiveness, to select the best RCO for minimising the risks. Finally, a cost benefit assessment is conducted to select the best risk control option using BN, where selections are based on economic terms. The four subjective novel FSA application methodologies in ship docking evolution are constructed from existing theoretical techniques and applied to real situations where data collection is otherwise not possible. The construction of the novel methodologies and the case study applications are the major contribution to knowledge in this thesis. It is concluded that the methodologies proposed possess significant potential for the application of FSA for ship docking evolution based on the validations of their corresponding case studies, which may also be applied with domain specification knowledge tailored to facilitate FSA application in other shipping industry sectors.
Supervisor: Yang, Zaili ; Rahin, Ramin ; Jones, Karl Sponsor: Not available
Qualification Name: Thesis (Ph.D.) Qualification Level: Doctoral