Academic literature on the topic 'Weather downtime'
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Journal articles on the topic "Weather downtime"
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PINHEIRO, Liliana, Conceicao FORTES, Maria Teresa REIS, Joao SANTOS, and Carlos GUEDES SOARES. "RISK FORECAST SYSTEM FOR MOORED SHIPS." Coastal Engineering Proceedings, no. 36v (December 28, 2020): 37. http://dx.doi.org/10.9753/icce.v36v.management.37.
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Port terminals downtimes lead to large economic losses and largely affect the port's overall competitiveness. In the majority of cases, port activities such as ships' approach maneuvers and loading/unloading operations, are conditioned or suspended, based solely on weather or wave forecasts. These forecasts do not always result in effective hazardous conditions for the ships. Additionally, moored ships often experience problems of excessive movements and mooring forces in apparent good weather conditions. If, instead, one could forecast the ships' movements and mooring forces, risk assessment would be much more accurate. This would allow selecting an appropriate reinforced mooring arrangement and thus minimizing effective terminal downtime. In this paper, the development of a risk forecast system for moored ships, that takes into account all of the moored ship's system, is detailed and an illustration on how it applies to real ports is presented.Recorded Presentation from the vICCE (YouTube Link): https://youtu.be/ugDN9Tqno3E
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Barker, Collin, Sam Cipkar, Tyler Lavigne, Cameron Watson, and Maher Azzouz. "Real-Time Nuisance Fault Detection in Photovoltaic Generation Systems Using a Fine Tree Classifier." Sustainability 13, no. 4 (2021): 2235. http://dx.doi.org/10.3390/su13042235.
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Nuisance faults are caused by weather events, which result in solar farms being disconnected from the electricity grid. This results in long stretches of downtime for troubleshooting as data are mined manually for possible fault causes, and consequently, cost thousands of dollars in lost revenue and maintenance. This paper proposes a novel fault detection technique to identify nuisance faults in solar farms. To initialize the design process, a weather model and solar farm model are designed to generate both training and testing data. Through an iterative design process, a fine tree model with a classification accuracy of 96.7% is developed. The proposed model is successfully implemented and tested in real-time through a server and web interface. The testbed is capable of streaming in data from a separate source, which emulates a supervisory control and data acquisition (SCADA) or weather station, then classifies the data in real-time and displays the output on another computer (which imitates an operator control room).
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Kikuchi, Yuka, and Takeshi Ishihara. "Assessment of weather downtime for the construction of offshore wind farm by using wind and wave simulations." Journal of Physics: Conference Series 753 (September 2016): 092016. http://dx.doi.org/10.1088/1742-6596/753/9/092016.
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Lawani, Kenneth, Chioma Okoro, Michael Tong, and Billy Hare. "Maximizing Construction of Timber Kit Homes Using Telescopic Crane to Improve Efficiency and Safety: A Case Study." Sustainability 12, no. 24 (2020): 10238. http://dx.doi.org/10.3390/su122410238.
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The challenges of improving efficiency and safety is a daunting task as workers are squeezed with an ever-dwindling resource pool and yet expected to deliver construction projects at optimum capacity. Improving efficiency and safety using telescopic cranes for the construction of Off-Site Manufacturing (OSM) timber kit homes is a viable option for the speedy delivery of new homes. An action research evaluated the maximization of the build and process efficiency and safety using a crane to erect wall panels, floors, and roofs. Data collection through direct observation assessed the labor uptime and downtime, including crane usage. A balanced score card was used by management for strategic organizational decision-making regarding the crane erection. The use of the crane reduced workplace manual handling of OSM panels, minimized the exposure of operatives to work at height risks, and eliminated alterations to scaffolds. However, the manual loading of thermal-insulated plasterboards to floor decks impacted the process efficiency and speed of installing the fixtures and increased the risk of musculoskeletal disorders. High labor downtimes were associated with the adverse weather conditions, which slowed the efficiency of the workforce during construction. The management’s inability to adequately plan the work program further hindered aspects of lifting operations and the speed and number of houses built.
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Kwilosz, Tadeusz, and Bogdan Filar. "Ekonometryczny model krótkoterminowego prognozowania zużycia gazu." Nafta-Gaz 77, no. 7 (2021): 454–62. http://dx.doi.org/10.18668/ng.2021.07.04.
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In order to develop a mathematical model of short-term gas demand, it is necessary to analyze the latest mathematical forecasting methods in order to select and adapt the right one (meeting the condition of efficiency and effectiveness). It is necessary to recognize and analyze factors (mainly environmental) affecting the result of short-term forecasts and sources of data that can be used. The result of the work is a numerical model of short-term gas demand for a selected territorial unit of the country. The developed model was calibrated and tested on historical data describing environmental conditions and real gas consumption. A heterogeneous linear econometric model was designed and calibrated on the basis of a selected set of attributes (explanatory variables). The estimated parameters of the model were statistically verified. It is worth noting that in the short term of the forecast (7 days) there are no significant changes in the gas market environment (launching new investments, connecting new users to the system, or changes in demand resulting from changing macroeconomic conditions). Other technical factors, such as production line failures at customers or industrial downtime, are difficult to predict, or knowledge about their occurrence is rarely available. For this reason, the only factors that may have an impact on changes in gas demand in the short term are weather factors, which were selected as explanatory variables for the developed model. Historical weather data was retrieved from the OpenWeatherMapHistoryBulk web service. Daily values of gas consumption for one of the voivodships of southern Poland were used as the response variable. The data was downloaded from the information exchange system of the transmission pipeline operator. The data covers a three-year period, as only such data has been made public. The explanatory variables include the daily values of weather data such as: average temperature, chilled temperature, minimum temperature, maximum temperature, atmospheric pressure, relative humidity, wind speed and wind direction.
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Harrison, Amy S., Laura A. Doyle, Mark Hurwitz, et al. "Converting a clinical indicator on patient missed treatments into a functional quality improvement metric." Journal of Clinical Oncology 32, no. 30_suppl (2014): 101. http://dx.doi.org/10.1200/jco.2014.32.30_suppl.101.
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101 Background: Extended time to complete a course of radiation can be detrimental to a patient’s overall local tumor control and survival. The American College of Radiology (ACR) Radiation Oncology Practice Guideline requires review of any unplanned interruptions during treatment. However, factors that impact missed treatments are neither required to be reviewed nor well characterized within the literature. We sought to understand the variables contributing to missed treatments by generating a functional metric for quality improvement. Methods: The departmental electronic medical record (EMR) was modified to create sub-sets of classifications for missed treatments. These categories were divided into intended and unintended breaks, with intended classification of physician prescribed break and eight subcategories of unintended breaks: patient preference, physician mandated, patient feels ill, transportation/social services, cancelled, no-show, weather, and machine downtime. Missed treatments were documented real-time by the treating radiation therapists using one of these eight categories. A custom report was generated to extract and separate missed treatments by category. Results: Over three years of ACR tracking, our department missed treatment rate ranged from 5-10%, out of 64,000 patient treatments. The new subcategory metric has been in place for the past six months. Overall compliance with documentation by therapists was 100%. The new metric yielded a six month total rate of missed treatments of 8% with detailed analysis showing the main reasons as: patient preferences (14%), inclement weather (14%), and machine down time (9%). Transportation was only a minor issue for the patient population. Conclusions: This stratification of a simple clinical indicator has identified the major factors influencing the total time to complete a course of treatment. Based on this analysis, our departmental quality committee is focusing on engaging and educating patients about the negative impact of missed treatments on their overall cancer care. Future research will attempt to identify patient characteristics that may predict individuals more likely to miss treatments.
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Pfeifer, Chris, Erik Brzozowski, Ralph Markarian, and Ramsey Redman. "LONG-TERM MONITORING OF SUBMERGED OIL IN THE GULF OF MEXICO FOLLOWING THE T/B DBL 152 INCIDENT." International Oil Spill Conference Proceedings 2008, no. 1 (2008): 275–78. http://dx.doi.org/10.7901/2169-3358-2008-1-275.
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ABSTRACT In November 2005, approximately 1.9 million gallons of Group V slurry oil was released in the western Gulf of Mexico following the allision of the double-hulled tank barge DBL 152 with the submerged remains of a pipeline service platform that collapsed during Hurricane Rita. The released oil was denser than seawater and sank to the bottom. After approximately six weeks of intermittent cleanup using diver-direct pumping, submerged oil recovery operations were suspended by the Unified Command based on the high percentage (50%) of weather-related downtime, as well as indications that recoverable accumulations of oil were dispersing naturally, which further reduced the feasibility of cleanup. However, the responsible party was required to develop and implement a long-term monitoring program (LTMP) to track the fate and transport of the sunken oil and determine the potential need for resuming oil recovery operations once more favorable weather patterns returned in the spring. This paper will present an overview of the approach, methods and results of the long-term monitoring efforts performed over a 14-month period following the incident. Major objectives of the LTMP included tracking the movement and fate of non-recovered submerged oil to assess its extent and continued dispersion; providing advance warning of potential impacts to Gulf Coast shorelines and other sensitive areas; and documenting changes in the oil'S chemical composition and physical properties through time due to weathering processes. Major findings of the LTMP include the dissipation of the main submerged oil field over the course of several months and the discovery, differential behavior and eventual dissipation of a discrete high-concentration oil patch found several miles from the incident location. The importance of long-term monitoring data in the decision-making process to determine both the need for and feasibility of resuming submerged oil recovery operations will be emphasized. Information on the fate and transport characteristics of submerged oil and the adaptation of monitoring techniques to address evolving needs will also be addressed. Both the incident-specific information and the practical lessons-learned are intended to benefit those who may be faced with monitoring submerged oil spills in the future.
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Aijaz, Saima, Jeffrey D. Kepert, Hua Ye, Zhendong Huang, and Alister Hawksford. "Bias Correction of Tropical Cyclone Parameters in the ECMWF Ensemble Prediction System in Australia." Monthly Weather Review 147, no. 11 (2019): 4261–85. http://dx.doi.org/10.1175/mwr-d-18-0377.1.
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Abstract Global ensemble prediction systems have considerable ability to predict tropical cyclone (TC) formation and subsequent evolution. However, because of their relatively coarse resolution, their predictions of intensity and structure are biased. The biases arise mainly from underestimated intensities and enlarged radii, in particular the radius of maximum winds. This paper describes a method to reduce this limitation by bias correcting TCs in the ECMWF Ensemble Prediction System (ECMWF-EPS) for a region northwest of Australia. A bias-corrected TC system will provide more accurate forecasts of TC-generated wind and waves to the oil and gas industry, which operates a large number of offshore facilities in the region. It will also enable improvements in response decisions for weather sensitive operations that affect downtime and safety risks. The bias-correction technique uses a multivariate linear regression method to bias correct storm intensity and structure. Special strategies are used to maintain ensemble spread after bias correction and to predict the radius of maximum winds using a climatological relationship based on wind intensity and storm latitude. The system was trained on the Australian best track TC data and the ECMWF-EPS TC data from two cyclone seasons. The system inserts corrected vortices into the original surface wind and pressure fields, which are then used to estimate wind exceedance probabilities, and to drive a wave model. The bias-corrected system has shown an overall skill improvement over the uncorrected ECMWF-EPS for all TC intensity and structure parameters with the most significant gains for the maximum wind speed prediction. The system has been operational at the Australian Bureau of Meteorology since November 2016.
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Gonçalves, Juliana De Lima, Nelson Yoshihiro Nakajima, Crismeire Isbaex, Pompeu Paes Guimarães, Roberto Tuyoshi Hosokawa, and Felipe Quartucci. "ESTUDO DE TEMPO E MOVIMENTO NA ETAPA DE SELEÇÃO DE MUDAS EM UM VIVEIRO FLORESTAL." FLORESTA 44, no. 4 (2014): 647. http://dx.doi.org/10.5380/rf.v44i4.28862.
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O objetivo deste artigo foi analisar a viabilidade da melhoria das condições de trabalho em um viveiro florestal adotando um ambiente protegido. A pesquisa focaliza o processo de seleção de mudas pelo estudo de tempo e movimento. Uma análise de viabilidade econômica utilizando os indicadores VPL e TIR foi realizada, levando em conta os tempos perdidos no processo e o custo de implantação de um galpão de seleção. O estudo de tempo mostrou que se essas atividades forem realizadas em um ambiente coberto, protegido e adequado, sem interferência de intempéries, proporcionará melhoria das condições de trabalho e aperfeiçoará o rendimento da produção. A análise de viabilidade econômica mostrou que, com base nos ganhos de rendimento calculados, o investimento total na construção do galpão é totalmente viável e o retorno financeiro do investimento acontecerá em dois anos, com um VPL de R$ 119.150,27, uma TIR de 14,5% e uma taxa de 8% ao ano. A construção do galpão possibilitará um ambiente de trabalho mais confortável para o trabalhador, economizando tempo das seleções de mudas e redução de custos da produção.Palavra-chave: Melhoria ergonômica; análise econômica; processo produtivo. AbstractTime and movement study in forest nursery. The objective of this research was to analyze the improvement of work conditions in a forest nursery by adopting a protected environment. The research focuses on the process of seedlings selections by the study of time and movement. It performed an economic viability assessment utilizing the indicators NPV and IRR, and considering the downtime in the process and costs of implementing a selection warehouse. The time and movement study showed that, if these activities were performed in a covered, protected and appropriate environment, without direct interference of weather, they will provide improvement of work conditions and optimize income productivity. The economic viability assessment showed that, based on calculated income gains, the overall investment used in the construction of a warehouse is fully viable and the financial return on the investment will happen in two years, with a NPV of R$ 119,150.27, an IRR of 14.5%, using a 8% discount rate. The warehouse construction will enable a more comfortable work environment for the worker, saving time of seedling selections and reduction in production costs.Keywords: Ergonomic improvement; economic analysis; production process.
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Wang, Wei, Yuan Tian, Cheng Liu, et al. "Investigating the performance of a greenhouse gas observatory in Hefei, China." Atmospheric Measurement Techniques 10, no. 7 (2017): 2627–43. http://dx.doi.org/10.5194/amt-10-2627-2017.
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Abstract. A ground-based high-resolution Fourier transform spectrometer (FTS) station has been established in Hefei, China to remotely measure CO2, CO and other greenhouse gases based on near-infrared solar absorption spectra. Total column measurements of atmospheric CO2 and CO were successfully obtained from July 2014 to April 2016. The spectra collected with an InSb detector in the first year were compared with those collected by an InGaAs detector from July 2015, demonstrating that InGaAs spectra have better signal-to-noise ratios and rms of spectral fitting residuals relative to InSb spectra. Consequently, the measurement precision of the retrieved XCO2 and XCO for InGaAs spectra is superior to InSb spectra, with about 0.04 and 0.09 % for XCO2, and 1.07 and 2.00 % for XCO within clear-sky days respectively. Daily and monthly averages of column-averaged dry air mole fraction of CO2 show a clear seasonal cycle, while the daily and monthly averages of XCO displayed no seasonal variation. Also, we analysed the relationship of the anomalies of XCO and XCO2, found that the correlations are only observable for individual days, and the data under different prevailing wind conditions during the observations displayed weak correlation. The observations based on the high-resolution FTS were also compared with the temporally coinciding measurements taken with a low-resolution solar FTS instrument, the EM27/SUN. Ratioing the daily averaged XCO2 of EM27 and FTS gives an overall calibration factor of 0.996 ± 0.001. We also compared ground-based observations from the Tsukuba TCCON station with our observations, the results showing that the variation in phase and seasonal amplitude of XCO2 are similar to our results, but the variation of XCO in Tsukuba is quite different from our data in Hefei. To further evaluate our retrieved data, we made use of satellite measurements. The direct comparison of our observations with the Greenhouse Gases Observing Satellite (GOSAT) data shows good agreement of daily median XCO2, with a bias of −0.52 ppm and standard deviation of 1.63 ppm. The correlation coefficient (R2) is 0.79 for daily median XCO2 between our FTS and GOSAT observations. Daily median Orbiting Carbon Observatory 2 (OCO-2) data produce a positive bias of 0.81 ppm and standard deviation of 1.73 ppm relative to our ground-based data. Our daily median XCO2 also show strong correlation with OCO-2 data, with correlation coefficient (R2) of 0.83. Although there were a limited number of data during the observations due to instrument downtime and adverse weather, the results confirm the suitability of the observatory for ground-based long-term measurements of greenhouse gases with high precision and accuracy, and fulfil the requirements of the Total Carbon Column Observing Network (TCCON).
Dissertations / Theses on the topic "Weather downtime"
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Tsekos, Charalambos. "Weather downtime statistics for marine projects." Thesis, Imperial College London, 1996. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.338583.
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Tessler, Thomaz Martino. "Weather downtime analysis for cutter suction dredgers." Universidade de São Paulo, 2016. http://www.teses.usp.br/teses/disponiveis/3/3135/tde-26012017-092026/.
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The dredging activity is increasing worldwide due to ships that require bigger drafts, and consequently deeper navigation channels. Some dredging projects requires the operation of cutter suction dredgers on open waters, once these are capable of removing compact sediments and rocks while still maintaining a good productivity. These facts motivated the creation of a weather driven downtime prediction software for this type of operation, based on simplified calculations of the main dredging systems of a CSD. The motions caused by waves, and the forces and moments caused on these dredgers by winds, waves and currents were analyzed in order to evaluate the influence of each parameter magnitude and direction on the behavior of the vessel. The main criteria of the dredger influenced by this conditions were determined by a literature review as being the swing winch required power, the interaction between the cutterhead and the soil, and the anchoring system resistance, this that can be both a spud pole system stress or the Christmas tree cable tension. In this research, only the spud pole system bending stress was considered. Three mathematical models were developed to represent those systems. Since the non-linearity of the relation between the reaction forces of the dredger and the soil was not an object of the study, this process is represented by a constant user defined reaction force and a horizontal cutterhead velocity model. The efficiency of these models were tested by applying them on a case study of the dredging of the Açu port on the Brazilian coast by the Taurus II dredger. Simultaneous wind, wave and current data data were used as input to these models by creating a time series scenario of the operation period. The results for both scenarios showed that the operation would be close to impossible due to wave generated dynamic stress on the spud pole.<br>A atividade de dragagem no mundo é cada vez mais significativa em função do aumento dos navios que operam em portos, estes que possuem maior calado e requerem, consequentemente, canais de navegação mais profundos. Alguns projetos de dragagem utilizam dragas de sucção e recalque em mar aberto, dada a capacidade destes equipamentos de remover sedimento compactado e rochas, ainda mantendo uma boa produtividade. Estes fatos motivaram a criação de um programa de previsão de downtime gerado por condições ambientais de dragas de sucção e recalque baseado em modelos matemáticos simplificados. Os movimentos causados por ondas, e as forças e momentos causados na draga por ventos, ondas e correntezas foram analisados de forma a se obter a influência da magnitude e direção de cada um destes parâmetros no comportamento da embarcação. Os principais sistemas da draga influenciados por estas condições foram determinados com base em uma revisão bibliográficas como sendo a potência requerida nos guinchos de varredura, a interação do cortador com o solo e a resistência do sistema de ancoragem, sendo este a tensão de flexão dinâmica na trave do spud ou as tensões de ancoragem pelo sistema de árvore de natal. Três modelos matemáticos foram desenvolvidos para representar estes sistemas. Considerando a não linearidade da interação entre a draga e o solo, este processo foi representado por uma força de reação definida pelo usuário e pela velocidade horizontal do cortador. A eficiência destes modelos foi testada ao aplicá-los em um estudo de caso da dragagem do porto de Açu, na costa brasileira pela draga Taurus II. Valores simultâneos de ondas, ventos e correnteza foram utilizadas como entrada nestes modelos, através da criação de um cenário hipotético de série temporal. Os resultados para ambos os casos demonstraram que a operação seria impossibilitada em função de tensões de flexão dinâmicas no spud maiores que o limite determinado.
Book chapters on the topic "Weather downtime"
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Musisinyani, Nyiko Cecil, Jacomine Grobler, and Mardé Helbig. "Weather Downtime Prediction in a South African Port Environment." In Lecture Notes in Computer Science. Springer International Publishing, 2020. http://dx.doi.org/10.1007/978-3-030-63799-6_19.
Full textConference papers on the topic "Weather downtime"
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Onea, Florin, and Liliana Rusu. "AN OVERVIEW OF THE BLACK SEA WEATHER DOWNTIME." In 52nd International Academic Conference, Barcelona. International Institute of Social and Economic Sciences, 2019. http://dx.doi.org/10.20472/iac.2019.052.049.
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Lambkin, David, Ian Wade, and Robin Stephens. "Estimating Operational Weather Downtime: A Comparison of Analytical Methods." In ASME 2019 38th International Conference on Ocean, Offshore and Arctic Engineering. American Society of Mechanical Engineers, 2019. http://dx.doi.org/10.1115/omae2019-95367.
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Abstract Weather downtime (WDT) is a logistical and financial risk when planning operations or offering services. Such risk is typically identified and managed in advance using statistical predictions based on historical weather data. Estimates of programme and cost for offshore construction work may vary, not because of the nature of a task, or the environment at the location, or the capability and price of a vessel, but because estimates of WDT have been calculated in different ways. Estimates of WDT are required in order to develop a realistic programme for complex and long duration projects. Therefore, a good understanding of the analytical options and a feel for the implications of the many and varied approaches is key to finding optimal solutions regarding WDT assessments. In this paper we consider a number of variants to the two principal approaches (namely ‘Weather Windows’ and ‘Simulation Based’ WDT analysis) to the derivation of WDT statistics. WDT estimates calculated using the same environmental input data, but alternative approaches are presented. The presentation highlights the potential variation in downtime statistics that can result from the alternative analyses, aiming to improve awareness of the application of such statistics when estimating project programme and cost at the planning stages.
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Mamerow, Steve, M. W. Brooker, and J. F. Brett. "Applications of a Systems Dynamics Weather Downtime Mobil for Drilling." In SPE Annual Technical Conference and Exhibition. Society of Petroleum Engineers, 1993. http://dx.doi.org/10.2118/26338-ms.
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van der Wal, Remmelt J., and Gerrit de Boer. "Downtime Analysis Techniques for Complex Offshore and Dredging Operations." In ASME 2004 23rd International Conference on Offshore Mechanics and Arctic Engineering. ASMEDC, 2004. http://dx.doi.org/10.1115/omae2004-51113.
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Offshore operations in open seas may be seriously affected by the weather. This can lead to a downtime during these operations. The question whether an offshore structure or dredger is able to operate in wind, waves and current is defined as “workability”. In recent decades improvements have been made in the hydrodynamic modelling of offshore structures and dredgers. However, the coupling of these hydrodynamic models with methods to analyse the actual workability for a given offshore operation is less developed. The present paper focuses on techniques to determine the workability (or downtime) in an accurate manner. Two different methods of determining the downtime are described in the paper. The first method is widely used in the industry: prediction of downtime on basis of wave scatter diagrams. The second method is less common but results in a much more reliable downtime estimate: determination of the ‘job duration’ on basis of scenario simulations. The analysis using wave scatter diagrams is simple: the downtime is expressed as a percentage of the time (occurrences) that a certain operation can not be carried out. This method can also be used for a combination of operations however using this approach does not take into account critical events. This can lead to a significant underprediction of the downtime. For the determination of the downtime on basis of scenario simulations long term seastate time records are used. By checking for each subsequent time step which operational mode is applicable and if this mode can be carried out the workability is determined. Past events and weather forecast are taken into account. The two different methods are compared and discussed for a simplified offloading operation from a Catenary Anchor Leg Mooring (CALM) buoy. The differences between the methods will be presented and recommendations for further applications are given.
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Brink, Mundy, and Morten Svendsen. "Marine seismic exploration using vertical receiver arrays: A means for reduction of weather downtime." In SEG Technical Program Expanded Abstracts 1987. Society of Exploration Geophysicists, 1987. http://dx.doi.org/10.1190/1.1892129.
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de Wilde, Jaap, and Johan Dekker. "Review of Hydrodynamic and Nautical Studies for Offshore LNG Operations." In ASME 2013 32nd International Conference on Ocean, Offshore and Arctic Engineering. American Society of Mechanical Engineers, 2013. http://dx.doi.org/10.1115/omae2013-11366.
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In this paper we review hydrodynamic and nautical studies for offshore LNG operations. Based on full mission bridge simulations, model tests campaigns, time domain simulations, fast time maneuvering simulations and downtime assessments, we address the major findings in terms of weather limitations, tugboat requirements and other critical aspects for the berthing and offloading operation.
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Naseri, Masoud. "On Maintainability of Winterised Plants Operating in Arctic Regions." In ASME 2017 36th International Conference on Ocean, Offshore and Arctic Engineering. American Society of Mechanical Engineers, 2017. http://dx.doi.org/10.1115/omae2017-61526.
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In Arctic regions, oil and gas (O&G) operations are adversely affected by harsh weather conditions and severe meteorological phenomena such as icing storms and, in certain regions, polar low pressures. Potential solutions, such as implementing winterisation concepts, are explored in the design and even operation phases in order to overcome such obstacles. Simply, the main aim of winterisation is to provide the crew and equipment units with a range of normal environmental and working conditions through, for instance, insulating equipment units, installing heat tracers, enclosing working areas, providing the crew with adequate clothing, etc. There are, however, some concerns about the efficiency of such winterisation measures and potential changes in operation risk level, of which the changes in plant downtime, production loss, and plant maintainability are the focus of present study. The issue of complex effects of winterisation measures on maintainability analysis of O&G plants operating in the Arctic offshore has gained little attention in the literature. In this study, different aspects of winterisation from the viewpoint of equipment maintainability are discussed. Further, a mathematical framework for maintainability analysis of equipment units subjected to winterisation measures is proposed. The impact of winterisation-related downtimes on plant downtime is analysed as well by employing a Monte Carlo system simulation technique. The application of the proposed framework is illustrated by a case study. The results are further compared with those for a non-winterised system designed for normal-climate regions.
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Fischer, Götz, and Stefan Schmitz. "Protect and Care (PaC) System for Lubrication Oil in Railway Applications." In ASME 2015 Internal Combustion Engine Division Fall Technical Conference. American Society of Mechanical Engineers, 2015. http://dx.doi.org/10.1115/icef2015-1027.
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In 2006, an automatic lube oil filtration system with an automatic backflushing filter and a centrifuge for railway engines was already presented at the ASME spring technical conference in Aachen. The technical benefit of a centrifuge compared to a cartridge filter is the ability to collect smaller particles. The power to drive the centrifuge comes from the engine oil pressure. This engine oil pressure is dependent from the engine speed. Many operating profiles of locomotives are showing low engine speed and load e.g. while waiting in switchyard and under arctic weather conditions the engines keep idling even during “downtime”. Under those conditions a centrifuge is ineffective or even out of operation.
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Decoret, Laurent, Laurent Bastard, and Tegwen de Kerdanet. "PAZFLOR Flexible Riser Diverless Bend Stiffener Fixation: Successful Innovation From Concept to Project Implementation." In ASME 2012 31st International Conference on Ocean, Offshore and Arctic Engineering. American Society of Mechanical Engineers, 2012. http://dx.doi.org/10.1115/omae2012-84104.
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For the TOTAL E&P Angola (TEPA) PAZFLOR field development, the decision was taken at the tender stage to propose an innovative diverless Bend Stiffener Fixation system (BSF) to connect the flexible risers to the FPSO. Avoiding diving intervention was driven primarily in order to minimize weather downtime during this critical offshore installation phase. Technip decided to develop its own system to retain full control of the design process and ensure it fulfilled all the installation constraint requirements. The patented system consists of a 3 part clamp activated by a hydraulic motor controlled from topside. An innovative disconnection device is used to release the riser pulling head once the bend stiffener is clamped to the I-tube. The development of the BSF was handled by an integrated team as a “project within the project”. From the start a robust design gate review process was applied to rapidly freeze the design of the system main components and enable the initial order placement of the long lead items. This was critical to ensure on time delivery to the FPSO Contractor. Extensive full scale testing was performed to ensure good reliability of all the system components. This testing enabled further optimization of parts of the system, particularly the items mounted on the risers to provide the maximum operability. Finally the involvement of the installation team from the onset ensured that robust installation procedures and operations were developed. The hook-up operations for the 21 risers was conducted safely with no weather downtime and with a riser connection cycle faster than planned. This proves that implementation of innovative design solutions can be successfully managed from initial concept to final installation within a project environment, ultimately enabling faster hand over for first oil.
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Chrolenko, Michael, Gerhard Gundersen, Tom Eirik Eikanger, and Boje Tveraaen. "Fully Coupled Time Domain Simulation Model Used for Planning and Offshore Decision Support During Riser Replacement Operations." In ASME 2018 37th International Conference on Ocean, Offshore and Arctic Engineering. American Society of Mechanical Engineers, 2018. http://dx.doi.org/10.1115/omae2018-78446.
Full textAbstract:
This paper presents a dynamic analysis model where installation vessel in coupled with the riser system using the SIMA software. The model is used to assess risk and weather limitations for riser replacements performed with SIMOPRO (Simultaneous Marine Operation and Production). The SIMA model has been used in several complex riser replacement operations in the North Sea during 2017, and proven to be a vital support tool for decision making offshore. The analysis supported critical operational decisions that resulted in reduced weather downtime and enabled the marine operations to be completed in a safe and efficient manner, while the platforms were kept in production. In the planning phase the analysis model was used to test specific DP settings to minimize vessel footprint, optimize procedure steps and provide accurate limits to an Activity Specific Operating Guideline (ASOG). The model was further used to verify vessel and riser response subjected to various “emergency situations”, such as wire break and partial or full vessel black-out. The results were used to establish detailed contingency procedures. During the offshore operations, analyses were performed at regular intervals at the vessel with measured and forecasted weather data, to monitor vessel response and predict vessel drift-off trajectories in case of a vessel black-out scenario. The information provided by the DP recorder was fed back into the fully coupled analysis model where the Kongsberg Maritime DP settings were updated to reflect actual vessel system behaviour. The analysis model also provided vessel drift-off predictions in good agreement with real drift-off test results. With the optimized fully coupled analysis model it was then possible to perform simulations of the planned installation steps based on forecasted weather data.