Early detection of rail defects is necessary for preventing derailments and costly damage to the train and railway infrastructure. A rail surface flaw can quickly propagate from a small fracture to a broken rail after only a few train cars have passed over it. Rail defect detection is typically performed by using an instrumented car or a separate railway monitoring vehicle. Rail surface irregularities can be measured using accelerometers mounted to the bogie side frames or wheel axles. Typical signal processing algorithms for detecting defects within a vertical acceleration signal use a simple thresholding routine that considers only the amplitude of the signal. As a result, rail surface defects that produce low amplitude acceleration signatures may not be detected, and special track components that produce high amplitude acceleration signatures may be flagged as defects. The focus of this research is to develop an intelligent signal processing algorithm capable of detecting and classifying various rail surface irregularities, including defects and special track components. Three algorithms are proposed and validated using data collected from an instrumented freight car. For the first two algorithms, one uses a windowed Fourier Transform while the other uses the Wavelet Transform for feature extraction. Both of these algorithms use an artificial neural network for feature classification. The third algorithm uses the Wavelet Transform to perform a regularity analysis on the signal. The algorithms are validated with the collected data and shown to out-perform the threshold-based algorithm for the same data set. Proper training of the defect detection algorithm requires a large data set consisting of operating conditions and physical parameters. To generate this training data, a dynamic wheel-rail interaction model was developed that relates defect geometry to the side frame vertical acceleration signature. The model was generated by using combined systems dynamic modeling, and the system was solved with a developed combined lumped and distributed parameter system numerical approximation. The broken rail model was validated with real data collected from an instrumented freight car. The model was then used to train and validate the defect detection methodologies for various train and rail physical parameters and operating conditions. / Ph. D.

Le squat est un défaut de fatigue de contact apparaissant à la surface du rail et dont le mécanisme d’amorçage est mal compris. Afin de pallier ce manque, une analyse tribologique locale de la bande de roulement du rail est mise en oeuvre à proximité d’un squat naissant. Cette caractérisation révèle une anisotropie importante des couches superficielles du rail associée aux développements de Transformations Tribologiques Superficielles. Ces résultats témoignent de conditions de contact roue/rail particulières dans la zone d’étude, notamment d’un niveau d’efforts de cisaillement inhabituel pour une voie en alignement. Dans le but de valider ces observations, plusieurs essais sont effectués. D’une part les conditions de contact roue/rail dans une zone de squats sont mesurées à partir d’un train instrumenté. D’autre part, la réponse tribologique de l’acier à rail à ces conditions de contact est étudiée à travers le suivi régulier d’une zone d’essais soumise à la circulation ferroviaire. Ces essais permettent d’identifier un déséquilibre important des efforts de traction sur les bogies moteurs et des glissements locaux élevés de la roue sur le rail. Différents mécanismes d’amorçage thermo-mécaniques sont alors proposés au sein d’un schéma global de la réponse tribologique de l’acier à rail. / Squats have recently become recognised as one of the major rolling contact fatigue defects in modern railway networks for which there is currently no solution other than preventive grinding operations or costly rail renewal. To better understand the entire damage mechanism of squat, A tribological and metallurgical analysis of the rolling band and the near surface layer was performed close to an incipient squat. This characterization show a significant anisotropy of the rail surface layer associated with developments of Tribological Transformation of Surface. These results reflect some specific wheel/rail contact conditions in this squat area, including an unusual level of shear forces in a straight track. In order to validate this observations, two tests were performed. On the one hand, the contact conditions in a squat area were measured from an instrumented train. On the other hand, the tribological response of the rail steel was studied through regular monitoring of a test site subjected to railway traffic. These tests allow to identify a high imbalance of the traction forces and the presence of local slips at the wheel/rail interface. Several thermomechanical initiation mechanism of squats are then given in a overall diagram of the tribological response of rail steels.

The adhesion in the wheel-rail contact can be effectively controlled by using the friction modifier. Adhesion control can reduce excessive wear of the contact bodies or noise. The essence of this diploma thesis is to determine the optimal amount of friction modifier in wheel-rail contact depending on the climatic and operating conditions. For experimental study of the behavior of the friction modifier, the twin-disc device is used. Twin-disc simulates and controls the most important operating parameters such as speed, slip, attack angle or contact pressure. On the basis of these findings, the off-board top-of-rail lubricator system was designed. This system controls the amount of friction modifier according to current climatic and operating conditions.

The aim of this work is make a new design and technology of the low-pressure output part of rail which is made in BOSCH DIESEL s.r.o. company. In the thesis is analyzed in detail the bending test, which is part of the quality control of the low-pressure welding joint. In the next part of the thesis is proposed the process of machining of this component, followed by experimental finding of welding parameters for resistance welding. Then several pieces are welded, which are measured and tested. The results of this tests are compared with customer requirements. Finally, a technical and economic evaluation of the change is made, which will save a considerable amount of money for the company.

This diploma thesis with a view to „common rail system for 4-cylinder CI-engine“ deals with the application of modern injection system „common rail“ to already existing compression-ignition tractor engine. The diploma thesis treats of the most necessary adjustments related with the replacement of injection systems which was solved in the way of the minimum adjustments. This kind of solution deals with an economic aspect of the problem. The reconstruction contains the engineering design of development of high pressure components and the suitability of their placing on engine.The primary adjustment of the application of system „common rail“ for existing tractor engine confirmed the possibility of this reconstruction.

Cette recherche a pour objet le transport ferroviaire interurbain de passagers aux Etats-Unis dans une double acception : les services ferroviaires classiques d’Amtrak et les projets de grande vitesse ferroviaire. Il s’agit de comprendre comment les politiques publiques concernant le mode ferroviaire fonctionnent, ce qu’elles contiennent et la manière dont elles sont élaborées et portées par les différents acteurs. L’originalité de la recherche repose sur son approche multiscalaire avec un aller-retour continu entre les différentes échelles d’analyse et sur son ambition d’analyser la territorialisation des politiques en faveur du mode ferroviaire interurbain grâce à plusieurs études de cas. L’analyse met en évidence le fait que s’impose une approche bottom-up pour le portage des projets, c’est le cas notamment pour le projet californien de GVF californien et la modernisation du corridor des Cascades. Cette logique est même poussée à l’extrême avec la multiplication de ces projets ferroviaires privés qui revendiquent leur indépendance par rapport à la puissance publique tant en termes de prise de décision que de gouvernance ou de financement. Cela semble éloigner définitivement toute tentative de définition d’un schéma national pour la grande vitesse ferroviaire, sur le modèle de ce qui s’est passé dans les pays historiques de la GVF, au-delà des considérations partisanes – c’est-à-dire de l’engagement traditionnellement plus fort du parti démocrate dans les grands investissements fédéraux. Deux conclusions en ressortent : en premier lieu, une uniformisation de cet argumentaire et des préconisations pour encourager de nouvelles politiques ferroviaires – effets structurants, rôle économique de la grande vitesse, lutte contre la congestion, report modal ; en second lieu, un engagement à toutes les échelles, tangible mais à divers degrés, des acteurs publics en faveur du mode ferroviaire. Il n’y a pas de projets, portés par des acteurs publics, de nouvelles lignes exclusivement réservées à la GVF. L’essentiel des corridors à grande vitesse concerne des corridors à vitesse élevée (higher speed rail) dont certains ont vocation à devenir à plus ou moins long terme à grande vitesse comme le corridor Nord-Est. Le projet californien, quant à lui, repose en partie sur la réalisation d’une nouvelle infrastructure mais aussi sur l’utilisation de tronçons existants améliorés. La territorialisation des projets ferroviaires passe par la conception et la mise en œuvre de réseaux de transport davantage intégrés – au moins sur le plan de la desserte et de la connexion physique – selon une véritable logique réticulaire. Après analyse des projets de modernisation de corridors à vitesse élevée et de construction de nouvelles infrastructures, nous constatons l’importance des gares et une mise à l’agenda d’une meilleure coordination entre transports et urbanisme par le soutien aux quartiers de gare. En effet, un projet de corridor ferroviaire, qui se trouve au croisement d’intérêts politiques, économiques, techniques et territoriaux, est bien au centre d’un processus de territorialisation qui inscrit matériellement l’infrastructure dans les espaces urbains, et d’un processus de politisation par une mobilisation des acteurs locaux. Les projets ferroviaires apparaissent comme un instrument permettant l’implantation d’équipements à l’échelle métropolitaine (gares, pôles intermodaux) et la structuration ou la reconfiguration du tissu urbain (quartiers de gare, projets plus vastes de renouvellement d’un quartier) / The subject of this research is intercity passenger rail transportation in the United States, approached from two perspectives: Amtrak’s traditional rail services and high-speed rail projects. The aim is to understand the workings of public rail transportation policies, what they contain, and how they are developed and pursued by the different actors. The originality of the research lies in its multiscale approach, with a constant back-and-forth between the different scales of analysis, and in its use of several case studies to analyze the territorialization of intercity rail transportation policies. The analysis demonstrates the emergence of a bottom-up approach to projects, notably apparent in the Californian HSR project and in the modernization of the Cascades corridor. This process has even gone to the extreme with the proliferation of private rail projects that stress their independence from government, be it in decision-making, governance, or funding. This seems definitively to preclude any attempt to establish a national framework for high-speed rail, like those found elsewhere in the world, regardless of party-political considerations, i.e. the traditionally greater enthusiasm of the Democratic Party for large-scale federal investment. Two conclusions emerge: first, the development of uniform arguments and recommendations to encourage new rail policies, emphasizing the structuring effects and economic role of high-speed rail, congestion reduction, modal shift; second, a tangible though uneven pro-rail position among public actors at all levels. Priority is placed on improving and modernizing existing corridors for the launch of higher-speed services, and then on hybrid networks that combine different types of infrastructures. There are no publicly backed projects for new lines exclusively dedicated to high-speed rail. Most of the high-speed corridors are in fact “higher-speed” corridors, some of which are intended to become high-speed at some time in the future, such as the Northeast corridor. The territorialization of rail projects entails the design and construction of transportation networks that are more integrated – at least in terms of service provision and physical connection – and genuinely interconnected. After analyzing projects for the upgrading of higher-speed corridors and the construction of new infrastructures, we note the importance of stations and the emphasis on the need for better coordination between transportation and urbanism through support for station districts. Indeed, a rail corridor project – situated at the intersection of political, economic, technical, and territorial interests – is the nucleus of a process of territorialization that materially embeds the infrastructure within urban spaces, and of a process of politicization through the involvement of local actors. Rail projects seem to be an instrument that leads to the implantation of metropolitan scale facilities (stations, intermodal hubs) and to the shaping or reshaping of the urban fabric (station districts, larger-scale district regeneration projects)

Detta examensarbete har utförts med begäran från Trafikförvaltningen. Arbetets huvudmål är att undersöka om det är möjligt att använda värmestrålning direkt mot ytan av strömskenan för att hindra isbildning på en kortare tid då absorptiviteten är som bäst. / This dissertation has been written with the request from Trafikvörvaltningen. The study's main goal is to investigate whether it is possible to use heat radiation against the surface of the third rail to prevent ice creation during the best efficient of absorptivity.

No description available.

Master of Landscape Architecture / Department of Landscape Architecture/Regional and Community Planning / William P. Winslow III / The proposed site development is situated in the ahupua’a of Honouliuli, in the district of Ewa on the island of Oahu, Hawaii and has been given the name Kaiaulu. Currently the University of Hawaii is planning to expand their campus in the Ewa district. The project site is 500 acres with the university occupying 204 acres. The remaining 296 acres of the site will be a mixed-use residential community. The design of the site addresses two main dilemmas: 1) creating a town-gown relationship between the university and surrounding mixed-use community and 2) promote the use of the two transit stations that will be located on the site for the new light rail system that will be implemented on the island in the next few years. To better understand the relationships between the institution and the surrounding neighborhood communities and how to successfully incorporate light rail stations into the communities, research was conducted to address the issues stated above. Literature was reviewed with a focus on the guidelines, principles, terms, and relative issues on each topic. Two precedent studies were then conducted relating to town-gown relationships and the implementation of light rail systems and stations. The program and the placement of the transit stations, the institution, and the mixed-use communities were based on the site inventory and analysis of the existing site. With the strategic placement of the transit stations and the university campus, students and residents of the surrounding community are encouraged to interact. Additionally, by making the transit stations welcoming, convenient, and safe, the light rail encourages the students and residents of the communities to lessen the use of their automobiles and use the public transit as a means of reaching their destinations around the island. The design of Kaiaulu brings the students of the institution and the residents and visitors of the surrounding communities together and creates a strong town-gown relationship.

The life of railway wheels and rails has been decreasing in recent years. This is mainly caused by more traffic and running at higher vehicle speed. A higher speed usually generates higher forces, unless compensated by improved track and vehicle designs, in the wheel-rail contact, resulting in more wear and rolling contact fatigue (RCF) damage to the wheels and rails. As recently as 15 years ago, RCF was not recognised as a serious problem. Nowadays it is a serious problem in many countries and ''artificial wear'' is being used to control the growth of cracks by preventive re-profiling and grinding of, respectively, the wheels and rails.  This can be used because a competition exists between wear and surface initiated RCF: At a high wear rate, RCF does not have the opportunity to develop further. Initiated cracks are in this case worn off and will not be able to propagate deep beneath the surface of the rail or wheel. When wheel-rail damage in terms of wear and RCF can be predicted, measures can be taken to decrease it. For example, the combination of wheel and rail profiles, or the combination of vehicle and track, can be optimised to control the damage. Not only can this lead to lower maintenance costs, but also to a safer system since high potential risks can be detected in advance. This thesis describes the development of a wheel-rail life prediction tool with regard to both wear and surface-initiated RCF. The main goal of this PhD work was to develop such a tool where vehicle-track dynamics simulations are implemented. This way, many different wheel-rail contact conditions which a wheel or a rail will encounter in reality can be taken into account. The wear prediction part of the tool had already been successfully developed by others to be used in combination with multibody simulations. The crack prediction part, however, was more difficult to be used in combination with multibody simulations since crack propagation models are time-consuming. Therefore, more concessions had to be made in the crack propagation part of the tool, since time-consuming detailed modelling of the crack, for example in Finite Elements models, was not an option. The use of simple and fast, but less accurate, crack propagation models is the first step in the development of a wheel-rail life prediction model. Another goal of this work was to verify the wheel-rail prediction tool against measurements of profile and crack development. For this purpose, the wheel profiles of trains running on the Stockholm commuter network have been measured together with the crack development on these wheels. Three train units were selected and their wheels have been measured over a period of more than a year. The maximum running distance for these wheels was 230,000 km. A chosen fatigue model was calibrated against crack and wear measurements of rails to determine two unknown parameters.  The verification of the prediction tool against the wheel measurements, however, showed that one of the calibrated parameters was not valid to predict RCF on wheels. It could be concluded that wheels experience relatively less RCF damage than rails. Once the two parameters were calibrated against the wheel measurements, the prediction tool showed promising results for predicting both wear and RCF and their trade-off. The predicted position of the damage on the tread of the wheel also agreed well with the position found in the measurements. / <p>QC 20150526</p>