Publications

In this attachment, the specific faultFault trees for different types of dynamic positioningDynamic positioning (DP) systems are presented and compared.

In this paper, we propose and demonstrate a method for risk-based path planning, generating risk-acceptable trajectories for an autonomous surface ship. This objective is achieved in two steps. The first step uses a dynamic probabilistic risk assessment method called K-shortest-paths Probabilistic Risk Assessment (KPRA), alongside risk models and dynamic system simulation, whose output is a list of paths ranked with respect to risk. Multiple risk influencing factors and accident types may be considered in this step. In this work, collision and powered grounding accidents, and their risk-influencing factors and indicators, are considered. The second step is to perform risk evaluation on the ranked scenarios, comparing them to predefined risk acceptance criteria and defining which scenarios have acceptable risk. Evaluating multiple paths allows operators to choose how strict the autonomous ship's decision-making should be regarding risk, avoiding the problem of minimization algorithms being too conservative in terms of risk. One of the risk-acceptable paths is then chosen as a local plan to be acted by the autonomous ship. This paper has two main scientific contributions. First, an online Bayesian belief network risk model for navigation accident probability is designed and integrated to improve KPRA. Second, we propose a modified guidance, navigation, and control framework for autonomous ships, to include risk-based planning. We implement the modified framework into a real autonomous surface vehicle (ASV) named Grethe and demonstrate the method's capabilities in field trials, where the ASV uses the method to generate local plans that avoid possible collision and grounding accidents.

The Norwegian fish farming industry is experiencing accidents that may have serious consequences for fish-farm operators, the environment, and the farmed fish themselves. Fatalities and serious personnel injuries, mass mortality of fish during and after operations, introgression of genes from farmed salmon, the spread of disease and material damage to assets are among the consequences. The reputation of the industry and the market value of its products may also suffer as a result of such incidents. Other industries have developed regulations aimed at preventing incidents called major accidents, which are usually defined as accidents that have different characteristics than occupational accidents. A holistic and efficient risk management system needs to cover all types of incidents. In spite of serious accidents, regulators have yet to adopt a holistic approach to the prevention of major accidents in Norwegian aquaculture. Here, we describe and discuss five main risk dimensions in the aquaculture industry that provide a holistic view of the complex risk picture of fish farming; fish welfare, personnel safety, risk to the environment, economic loss and food safety. Hazards that emerge in the fish production process and in the local environment, have consequences both for the fish farm and for society as a whole. On the basis of characteristics drawn from definitions of major accident regulations in other industries and the risk dimensions of fish farming, we propose a general definition of major accidents. The definition is discussed based on the type of risks that occur in fish farming, and with an emphasis on accidents that have happened in the Norwegian aquaculture industry. The occurrence of major fish farming accidents shows that a systemic approach to safety and risk management is needed. Regulators and industry are already looking to the offshore petroleum industry in order to develop and adapt technology and risk management for aquaculture. Approaches to risk regulation in the two industries are discussed and some differences pointed out. Barrier management is one of the potentially holistic and systemic major risk management methods required in offshore regulation that is seen as a possible way forward for the fish farming industry, and we offer some reflections on adopting this method to fish farming.

The management of aging of plants has become an important issue for oil and gas (O&G) companies that intend to extend the lifetime of their facilities. Important requirements are that the installations must be safe and economical to remain in operation. This can be achieved by implementing aging plant management programs to control and mitigate the degradation of the facilities. Aging plants have been a crucial topic for several years within the nuclear power industry, but it is a relatively novel area for the offshore O&G industry. To develop a successful aging plant management program for an existing offshore O&G installation, it is necessary not only to learn from the experience of other industries but also to understand and address the specific challenges for managing the aging of these facilities. The objective of this article is to outline these issues and to highlight future challenges. © 2011 American Institute of Chemical Engineers Process Saf Prog 2011

The analytic hierarchy process has been used to elicit the knowledge of maritime transport stakeholders, such as seafarers, authorities, insurers and academics, regarding human factors and risk-reducing measures for ship groundings. Measures against human fatigue, alcohol abuse, language barriers, poor bridge management and safety climate have been compared with regard to costs and benefits. The measures are discussed in the context of large ships on a voyage of at least 24 h containing Bridge Resource Management. The study shows that stakeholders consider the costs of the measures to reduce human fatigue at sea surpass the benefits. Measures against alcohol abuse are regarded as the most cost–benefit efficient. Also, the stakeholders consider the watch scheme 8–4–4–8 to be less fatiguing than the 12–12 watch scheme. In addition, the results of the study support previous findings that inadequate manning levels contribute the most to human fatigue within the bridge management team.

The decarbonization of the shipping industry is a hot topic and new emission reduction goals, regulations, and initiatives all over the world underline its importance. These goals apply to the ocean going fleet, as well as coastal shipping and fisheries. Both academia and industry, work on the development and testing of new technologies to reach emission reduction targets. Besides technical feasibility and economic viability, the safety of new power and propulsion systems must be considered in this process. In this paper, the Systems Theoretic Process Analysis (STPA) method is used for hazard identification and comparison of two alternative hybrid power and propulsion systems for a small-scall fishing vessel. The assessment method allows for identifying focus areas for hazard reduction in a systematic manner. System safety requirements derived from the assessment can be considered when designing power and propulsion systems. Based on the results, a discussion of the method and the usefulness of the results is given. The main findings are that the assessment provides valuable insights into the hazards introduced by new power and propulsion systems in a qualitative manner. For a quantification of the risk, further work and an extension of the assessment are needed. The STPA results show that especially the control of the power sources and their interactions internally and externally with the consumer side are crucial. Therefore, special attention should be given to the design of the automated control system, feedback system, and user interaction with the system.

In this chapter, the scope, objective, and limitations of this book are discussed. First, the problem under study and background of the risk assessmentRisk assessment in automated and autonomousAutonomous marine systems are presented. Then, consideration and limitations of safetySafety and risk assessmentRisk assessment are discussed, and the dynamic positioningDynamic positioning (DP) system as an example of an advanced and complex systemComplex systems relevant for autonomousAutonomous marine and maritime systemsMarine and maritime systems is presented. The chapter is finalized by presenting the book structure.

Assessing the technical condition and remaining useful life of aging equipment is crucial for the life extension of O&G facilities. In order to perform a reliable assessment, models describing the degradation of the equipment are necessary. However, the use of accurate physical models for this purpose may be challenging. Some reasons are that the equipment can be exposed to various degradation mechanisms, which may be influenced by different operating conditions, and that the operational data may be scarce. This paper presents a systematic approach for modelling different degradation mechanisms, assessing the technical condition of a component, and quantifying the expected remaining useful life. The quantification is performed using a Bayesian network. Finally, the application of the proposed model is illustrated with the analysis of a fire water pump.

Systems engineering principles in fisheries management may structure and improve the decision-making process. Sustainability in the fishing fleet is comprised of economic, environmental, and social dimensions. Even though the total system value may be constituted by economic factors and technical factors, non-market issues, such as environmental and social issues, have an increasingly important impact on the economic performance of a system or company. Life cycle cost (LCC) is related to the systems engineering process, because economic considerations are very important in the process of creating systems. LCC involves evaluation of all future costs related to the life cycle of a system. The main objective of this article is to discuss the usefulness of LCC as a method to enhance sustainable designs of fishing vessels for ship owners, and to improve the decision-bases for fisheries management.

No abstract is provided for this article.

Recently, numerous organizations have made progress in developing autonomous ships, motivated by, among other factors, the potential for increased safety. This applies especially to accidents involving human error, as autonomous ships would remove operator role from all or most operations. The reality is that although the human role is reduced, autonomous ships would still rely on operators for supervision, remote control, and involvement in case of a glitch or an unexpected situation. Thus, autonomous ships do not fully eliminate the possibility of human error. In this study, we assess the potential for human error in autonomous ship operations. We analyze an unmanned autonomous ship operation, and through a generic analysis of the interaction between operators working a Shore Control Centre (SCC) and system, we identify possible Human Failure Events (HFE). This provide a starting point for performing human reliability analysis of autonomous ships operation.

Vessel losses of command (e.g., propulsion, electrical power, or steering failure) can serve as the initiating event for significant maritime accidents, such as grounding. It is therefore important to estimate the frequency of such events for navigational risk assessments. Despite the existence of previous studies, new data have become available that may reveal more precise and useful information for risk estimations and accident prevention. This paper analyzes two databases of vessel losses of command within Norway's economic exclusive area over a five year period. The study utilizes a novel database of incidents observed by the Norwegian Coastal Administration's (NCA) Vessel Traffic Services (VTS), in addition to incidents reported to IHS Markit over the same five year period. Automatic identification system (AIS) data is used to construct activity metrics of vessel activity, which are used to compute vessel loss of command incidence rates for ship types. To account for under-reporting, capture–recapture methods are used to calculate adjusted incidence-rates. The duration of each incident is recorded and used to construct distributions of repair times. Probabilities of towing and anchoring are computed for ship types and incident location. The results indicate that previous studies may have underestimated the incidence of vessel loss of command. Using the best-case scenario, cargo ships and tankers suffer losses of command more frequently than other ship types. Significant under-reporting of losses of command was observed in the IHS Markit database.

Failures in critical infrastructures may be hazardous to population, economy, and national security. There can be strong interdependencies between various infrastructures, but these interdependencies are seldom accounted for in current risk and vulnerability analyses. To reduce probability and mitigate consequences of infrastructure failures, these interdependencies have to be assessed. The objective of this paper is to present a method for assessing interdependencies of critical infrastructures, as part of a cross-sector risk and vulnerability analysis. The method is based on a relatively simple approach applicable for practitioners, but may be extended for more detailed analyses by specialists. Examples from a case study with the Emergency Preparedness Group of the city of Oslo, Norway, are included.