Ship collision and grounding events constitute a major hazard for ship operations, and ship collision risk analyses have to be carried out for installations such as offshore structures for extraction of hydrocarbons, offshore wind farms, and bridges spanning waterways. This book provides assessment procedures for ship collision and grounding analysis and includes probabilistic methods for collision and grounding risk assessment, estimation of the energy released during collisions, and prediction of the extent of damage on the involved structures.
The main feature of the book is that it encapsulates reliable and fast analysis methods for collision and grounding assessment and the methods have been extensively validated with experimental and numerical results. In addition, all the described analysis methods include realistic calculation examples so as to provide confidence in their use to eventually conduct the required assessment according to the rules and design codes. The book is intended as a handbook for professionals and researchers in the industry dealing with design and analysis of ships and offshore structures. The book can also be used as a text book for postgraduate courses orientated towards the design and analysis of ship and offshore structures.
Slugging flow in offshore oil & gas multi-phase transportation pipelines cause big challenges as the flow regime induces flow and pressure oscillations in the multi-phase pipelines. The negative impacts of the most severe slugs are significant and thus the elimination of slugging flow in the pipelines is a highly investigated topic. To eliminate the slug in an online manner real-time slug detection methods are often required. Traditionally topside pressure transmitters upstream of a 3-phase separator have been used as the controlled variable. In this paper Electrical Resistivity Tomography (ERT) has been examined as an alternative to the traditional pressure transmitters. A lab-scaled testing facility has been constructed in order to obtain test data from an ERT transmitter with 12 probes. Different flow regimes have been generated by a pump and a compressor where 2-phase flow can be tested. Based on the results, the study concludes that the ERT is able to detect the slug very well when the oil and water are well mixed. Furthermore, the traditional pressure transmitters have the limitation that pressure variations can be caused by other operating conditions than slug, such as change in the back pressure from control valves. The biggest limitation using ERT is the lack of ability to distinguish between gas and oil, and thus the ERT can only be used as an effective slug detect measurement when the oil-to-water ratio is low.
The upstream offshore multi-phase well-pipeline-riser installations are facing huge challenges related to slugging flow: An unstable flow regime where the flow rates, pressures and temperatures oscillate in the multi-phase pipelines. One typical severe slug is induced by vertical wells or risers causing the pressure to build up and hence originates the oscillating pressure and flow. There exist many negative consequences related to the severe slugging flow and thus lots of investments and effort have been put into reducing or completely eliminating the severe slug. This paper reviews in detail the state-of-the-art related to analysis, detection, dynamical modeling and elimination of the slug within the offshore oil & gas Exploration and Production (E&P) processes. Modeling of slugging flow has been used to investigate the slug characteristics and for design of anti-slug control as well, however most models require specific facility and operating data which, unfortunately, often is not available from most offshore installations. Anti-slug control has been investigated for several decades in the oil & gas industry, but many of these existing methods suffer the consequent risk of simultaneously reducing the oil & gas production. This paper concludes that slug is a well defined phenomenon, but even though it has been investigated for several decades the current anti-slug control methods still have problems related to robustness. It is predicted that slug-induced challenges will be even more severe as a consequence of the longer vertical risers caused by deep-water E&P in the future.
The current offshore oil & gas multi-phase production and transportation installations have big challenges related to the slugging flow: An unstable multi-phase flow regime where the flow rates, pressures and temperatures oscillate in the considered processes. Slug can be caused by different operating conditions and installation structures. The most severe slugs are often induced in long vertical risers or production wells, where liquid blocks gas at the riser/well base and correspondingly it causes the pressure to accumulate and hence originates the oscillating performance. There are many severe consequences to the production processes because of the slugging flow. This paper reviews some observed latest status and key challenges about slug detection, dynamical modeling and elimination of slugging flows. Mathematical modeling of slug has been used to investigate the slug mechanism and anti-slug control. Most of available models are based on mass-balance formulations, which often require sufficient data for reliable parameter tuning/identification. Slug elimination and control have been investigated for many years and there exist many solutions to eliminate the slug, but some of these methods can simultaneously reduce the oil & gas production, which is a very big concern as the production rate is the key evaluation parameter for offshore production. We conclude that the slugging flow is a well-defined phenomenon, even though this subject has been extensively investigated in the past decades, the cost-effective and optimal slug modeling and control are still open topics with many related challenges.
Background: Evidence on workplace safety and health promotion interventions shows that the
interventions have failed to demonstrate substantial benefits for seafarers. It is therefore important to explore what is the evidence of interventions with empowering elements regarding seafarers’ safety and health. This study aims to examine what is known about health promotion interventions in a maritime setting and whether they include an empowerment perspective. And secondly, what were the effects of these efforts. Methods: We systematically searched PubMed and NLM Gateway (for MEDLINE), Institute of Scientific Information/Web of Science (ISI/WOS), and SCOPUS up to July 2022 by using standard keywords including empowerment in the maritime setting. Data extraction was done by three independent reviewers. The quality of included studies was assessed by using the critical appraisal checklists from Joanna Briggs institute. Results: From 3313 studies initially identified, 10 articles met the inclusion criteria and were included in this review. Interventions covered a wide range of topics such as educational interventions on safety, first aid training, weight management, healthy eating, sexual harassment, alcohol abuse, and cancer prevention training. None of the studies applied a specific theory or definitions of empowerment
even though their aim was to increase seafarers’ empowerment in these areas. Conclusion: The studies focused on improving the safety and health status of the seafarers, however, they had no explicit focus on participation and empowerment. Increasing research with an empowerment approach in maritime sector is recommended to enhance the feasibility and
success of the programs in this hard-to-reach occupation.
Background: Evidence on workplace safety and health promotion interventions shows that the interventions have failed to demonstrate substantial benefits for seafarers. It is therefore important to explore what is the evidence of interventions with empowering elements regarding seafarers’ safety and health. This study aims to examine what is known about health promotion interventions in a maritime setting and whether they include an empowerment perspective. And secondly, what were the effects of these efforts. Methods: We systematically searched PubMed and NLM Gateway (for MEDLINE), Institute of Scientific Information/Web of Science (ISI/WOS), and SCOPUS up to July 2022 by using standard keywords including empowerment in the maritime setting. Data extraction was done by three independent reviewers. The quality of included studies was assessed by using the critical appraisal checklists from Joanna Briggs institute. Results: From 3313 studies initially identified, 10 articles met the inclusion criteria and were included in this review. Interventions covered a wide range of topics such as educational interventions on safety, first aid training, weight management, healthy eating, sexual harassment, alcohol abuse, and cancer prevention training. None of the studies applied a specific theory or definitions of empowerment even though their aim was to increase seafarers’ empowerment in these areas. Conclusion: The studies focused on improving the safety and health status of the seafarers, however, they had no explicit focus on participation and empowerment. Increasing research with an empowerment approach in maritime sector is recommended to enhance the feasibility and success of the programs in this hard-to-reach occupation. Systematic review registration number in PROSPERO: CRD42021260098.
Background: Seafarers are at an increased risk of developing cardiovascular diseases (CVDs), potentially due to a stressful working environment and behavioral risk factors. To develop better prevention strategies, it is important to elucidate the extent of this risk. Therefore, we conducted a systematic literature review on CVD in seafarers. Method: We conducted systematic searches in five databases. All studies investigating CVDs among occupational seafarers, published in articles or conference papers, were eligible for inclusion. The identified records were screened and reviewed by two independent researchers, who also evaluated the methodological quality of the included studies. Results: Three thousand nine hundred and seventeen records qualified for screening, and 55 were eligible for inclusion. Most of the studies were observational, including cohort, frequency, incidence or prevalence studies, and review of case records. Around half were assessed at risk of biased findings. Participants in the studies were primarily from North America or the European continent and work onboard transportation vessels. Many studies investigated CVDs as a cause of death, focusing on conditions such as CVD, ischemic heart disease, and myocardial infarction. Frequency of CVD conditions varied but indicate that seafarers face a greater risk compared to the reference populations or control groups. Environmental factors were mainly investigated as risk factors. Conclusion: Our results indicate a higher risk of CVDs among seafarers compared to reference or control groups. However, due to the variable quality of the evidence, well-designed studies are needed to establish the causes of cardiovascular mortality and morbidity in seafarers and to investigate behavioral aspects of cardiovascular risk.
Recent advances, especially in deep learning, allow to effectively detect ship targets in surveillance videos. However, the translation of these detections to the real-world locations of ships has not been sufficiently explored. The common approach in the literature is using a transformation matrix to convert a pixel to a real-world coordinate. However, this approach has three shortcomings: first, a set of reference point pairs has to be manually prepared to establish the matrix; second, the matrix always maps a pixel to the same real-world coordinate, ignoring that there is no one-to-one correspondence between discrete pixel coordinates and continuous real-world coordinates; third, this approach can only work with one camera. In light of this, we propose a technique PixelToRegion that explicitly takes into account the uncertainty in coordinate conversion by mapping each pixel to a spatial polygon. Next, we propose a new algorithm MCbSLE that can estimate ship locations using pixel sets from multiple cameras. The precision of location estimation by MCbSLE is enhanced through spatial intersection between polygons from different cameras. Experiments are conducted under 16 carefully designed multi-camera settings to evaluate MCbSLE wrt four factors: different ports, the number of cameras, the distance between cameras, and camera headings. Results on one-day ship trajectory data show that (1) an 79.8% accuracy in the number of coordinates can be achieved by MCbSLE when there are no more than 10 ships in camera views; (2) using multiple cameras can improve the precision of location estimation by one order of magnitude compared with using one camera.
Cod stocks in the Danish inland waters and the Baltic Sea have collapsed today. Fishing vessels have therefore been required to install video cameras that film the catch for control purposes. The use of artificial intelligence for automated documentation of the catch is therefore a promising solution for control as well as research and management purposes that can contribute to rebuilding cod stocks and ensuring sustainable fishing in the future.
This paper presents the design and development of a conceptual prototype of an autonomous self-driven inline inspection robot, called Smart-Spider. The primary objective is to use this type of robot for offshore oil and gas pipeline inspection, especially for those pipelines where the conventional intelligent pigging systems could not or be difficult to be deployed. The Smart-Spider, which is real-time controlled by its own on-board MCU core and power supplied by a hugged-up battery, is expected to execute pipeline inspection in an autonomous manner. A flexible mechanism structure is applied to realize the spider's flexibility to adapt to different diameters of pipelines as well as to handle some irregular situations, such as to pass through an obstructed areas or to maneuver at a corner or junction. This adaptation is automatically controlled by the MCU controller based on pressure sensors' feedback. The equipped devices, such as the selected motors and battery package, as well as the human-and-machine interface are also discussed in detail. Some preliminary laboratory testing results illustrated the feasibility and cost-effectiveness of this design and development in a very promising manner.