Atmospheric Ice Accretion on Railway Overhead Powerline Conductors- A Numerical Case Study

Ice accretion on railway overhead contact wires/conductors can cause various critical operational and safety issues such as overloading, arc formation, mass imbalance, and wire galloping. The focus of this multiphase numerical study is to understand and analyze the ice accretion physics on railway overhead powerline conductors at various operating conditions. In this regard, two different geometric shape conductors of 12 mm diameter, 1) a grooved shape contact wire (like an actual railway conductor); 2) a standard circular shape contact wire are used. Computational Fluid Dynamics (CFD) based numerical simulations are carried out for both geometric configurations at different operating parameters such as wind speed, Liquid Water Content (LWC), cloud droplet size distribution, Median Volume Diameter (MVD), and atmospheric temperature. Analysis shows that variation in the operating weather parameters for both geometric configurations considerably affect the ice accretion, both in terms of accreted ice thickness and mass

Non-invasive dynamic condition assessment techniques for railway pantographs

The railway industry desires to improve the dependability and longevity of railway pantographs by providing more effective maintenance. The problem addressed in this thesis is the development of an effective condition-based fault detection and diagnosis procedure capable of supporting improved on–condition maintenance actions. A laboratory-based pantograph test rig established during the course of the project at the University of Birmingham has been enhanced with additional sensors and used to develop and carry out dynamic tests that provide indicators that support practical pantograph fault detection and diagnosis. A 3D multibody simulation of a Pendolino pantograph has also been developed. Three distinct dynamic tests have been identified as useful for fault detection and diagnosis: (i) a hysteresis test; (ii) a frequency-response test; and (iii) a novel changing-gradient test. These tests were carried out on a new Pendolino pantograph, a used pantograph about to go for an overhaul, the new pantograph with individual parts replaced by old components, and on the new pantograph with various changes made to, for example, the greasing or chain tightness. Through a comparison of absolute measurements and features acquired from the three dynamic tests, it was possible to extract features associated with different failure modes. Finally, with a focus on the practical constraints of depot operations, a condition-based pantograph fault detection and diagnosis routine is proposed that draws on decision tree analysis. This novel testing procedure integrates the three dynamic tests and is able to identify and locate common failure modes on pantographs. The approach is considered to be appropriate for an application using an adapted version of the test rig in a depot setting

Railway operations in icing conditions: a review of issues and mitigation methods

This article focuses on studying the current literature about railway operations in icing conditions, identifying icing effects on railway infrastructure, rolling stock, and operations, and summarizing the existing solutions for addressing these issues. Even though various studies have been conducted in the past on the impact of winter, climate change, and low temperatures on railway operations, not much work has been done on optimizing railway operations under icing conditions. This study demonstrates that further research is needed to better understand ice accretion and its effects on different parts of railways. It appears that railway infrastructure faces serious problems during icing conditions, and additional research in this field is required to precisely identify the problems and suggest solutions. Therefore, it is important to enhance the knowledge in this area and suitable optimal and cost-effective ice mitigation methods to minimize icing effects on railway operations and safety

Modeling and experimental identification of vibrating structures: localized and distributed nonlinearities

L'abstract è presente nell'allegato / the abstract is in the attachmen

Power Quality in Electrified Transportation Systems

"Power Quality in Electrified Transportation Systems" has covered interesting horizontal topics over diversified transportation technologies, ranging from railways to electric vehicles and ships. Although the attention is chiefly focused on typical railway issues such as harmonics, resonances and reactive power flow compensation, the integration of electric vehicles plays a significant role. The book is completed by some additional significant contributions, focusing on the interpretation of Power Quality phenomena propagation in railways using the fundamentals of electromagnetic theory and on electric ships in the light of the latest standardization efforts

Atmospheric Ice Accretion on Railway Overhead Powerline Conductors- A Numerical Case Study

Ice accretion on railway overhead contact wires/conductors can cause various critical operational and safety issues such as overloading, arc formation, mass imbalance, and wire galloping. The focus of this multiphase numerical study is to understand and analyze the ice accretion physics on railway overhead powerline conductors at various operating conditions. In this regard, two different geometric shape conductors of 12 mm diameter, 1) a grooved shape contact wire (like an actual railway conductor); 2) a standard circular shape contact wire are used. Computational Fluid Dynamics (CFD) based numerical simulations are carried out for both geometric configurations at different operating parameters such as wind speed, Liquid Water Content (LWC), cloud droplet size distribution, Median Volume Diameter (MVD), and atmospheric temperature. Analysis shows that variation in the operating weather parameters for both geometric configurations considerably affects the ice accretion, both in terms of accreted ice thickness and mass

Estimating Workforce Development Needs for High-Speed Rail in California, Research Report 11-16

This study provides an assessment of the job creation and attendant education and training needs associated with the creation of the California High-Speed Rail (CHSR) network, scheduled to begin construction in September 2012. Given the high profile of national and state commitment to the project, a comprehensive analysis that discusses the education, training, and related needs created during the build out of the CHSR network is necessary. This needs assessment is achieved by means of: 1) analyzing current high-speed rail specific challenges pertaining to 220mph trains; 2) using a more accurate and robust “bottom-up” approach to estimate the labor, education, skills, and knowledge needed to complete the CHSR network; and 3) assessing the current capacity of railroad-specific training and education in the state of California and the nation. Through these analyses, the study identifies the magnitude and attributes of the workforce development needs and challenges that lie ahead for California. The results of this research offer new insight into the training and education levels likely to be needed for the emergent high-speed rail workforce, including which types of workers and professionals are needed over the life of the project (by project phase), and their anticipated educational level. Results indicates that although the education attained by the design engineers of the system signifies the most advanced levels of education in the workforce, this group is comparatively small over the life of the project. Secondly, this report identifies vast training needs for the construction workforce and higher education needs for a managerial construction workforce. Finally, the report identifies an extremely limited existing capacity for training and educating the high-speed rail workforce in both California and in the U.S. generally

A study into intelligent Neutral Section fault monitoring system on the Coal line using wireless sensor networks

Abstract: Machine learning a subdivision of artificial intelligence which is popular nowadays particularly where large amounts of data are to be evaluated unsupervised by applying algorithms thereby requiring less human effort to process the measurements. This paper presents an intelligent fault monitoring on the overhead wires using wireless sensor network (WSN). The current method used to monitor failures requires both foot patrols and vehicle measurements using cameras, however these methods are both labour and time intensive in preparing and analysing the data from the inspections. An intelligent method is proposed to reduce the amount of time spent on labour intensive inspections through data aggregation and machine learning. Ma-chine learning offers additional flexibility for identifying the type of the faults, finding otherwise hidden pat-terns and grouping instances of events accordingly based on similarities. WSN will convey the measured data to the cloud via the router for computation thereby providing notifications in real-time and also the data can be viewed anywhere by the operator. K-means clustering algorithm will then be applied later using sensors data via Matlab/Simulink