Dissertations / Theses on the topic 'Rail'
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1
Holmlund, Gabriel. "RFID in Rail : RFID tracing of rail-borne cargo." Thesis, Mittuniversitetet, Avdelningen för informations- och kommunikationssystem, 2015. http://urn.kb.se/resolve?urn=urn:nbn:se:miun:diva-25824.
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SCA transports timber via rail from railway terminals in western Sweden to saw and/or pulp mills located on the east coast. Sometimes timber wagons are lost due to damages inflicted when loading the wagon. Wagons can also be decommissioned for maintenance conducted by the Swedish Transport Administration. Both situations are unpredictable and causes many types of problems. If the wagons could be automatically traced these problems could be predicted and pre-emptive actions could be taken. All wagons used by SCA are equipped with RFID tags and RFID readers are installed at the railway terminals. The purpose of this thesis is to equip the RFID readers with Internet access, collect the data read by the RFID readers and present this data in a single page web application. The actual data collection is done by an already existing system which pushes the train data to the back-end part of the application. The front-end part is made with a JavaScript framework named Ember.js and the back-end part is made with ASP .NET Web API and SQL Server. The application is finished and verified with various tests but is not put in production due to a negotiation delay between SCA with a third-party consultant.
2
Soenneker, Richard (Richard Joseph) 1978. "Design of a bipolar rail-to-rail operational amplifier." Thesis, Massachusetts Institute of Technology, 2001. http://hdl.handle.net/1721.1/86734.
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Thesis (M.Eng. and S.B.)--Massachusetts Institute of Technology, Dept. of Electrical Engineering and Computer Science, 2001.Includes bibliographical references (leaves 66-67).
by Richard Soenneker.
M.Eng.and S.B.
3
Hudzik, Martin. "Návrh Rail-to-Rail proudového konvejoru v technologii CMOS." Master's thesis, Vysoké učení technické v Brně. Fakulta elektrotechniky a komunikačních technologií, 2016. http://www.nusl.cz/ntk/nusl-242143.
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Master’s thesis deals with design of rail-to-rail second generation current conveyor in CMOS technology. Describes principles of function of different generations of current conveyors, as well as the basic principle of design of second generation current conveyor based on operational amplifier. Addresses circuit topology of input rail-to-rail stage and class AB output stage. The objective of this thesis is to design, characterize performance and create layout of second generation current conveyor with input common mode voltage rail-to-rail capability in ONSemi I3T25 technology.
4
Orvnäs, Anneli. "Simulation of Rail Wear on the Swedish Light Rail Line Tvärbanan." Thesis, KTH, Spårfordon, 2005. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-26310.
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Rail wear can result in extensive costs for the track owner if it is not predicted and preventedin an efficient way. To limit these costs, one measure is to predict rail wear through wear simulations. The purpose with this work is to perform simulations of successive rail wear on the Swedish light rail line Tvärbanan in Stockholm, by means of the track-vehicle dynamics software GENSYS in combination with a wear calculation program developed in MATLAB. The simulation procedure is based on a methodology with a simulation set design, where the simulations to be performed are selected through a parametric study. The simulations include track-vehicle simulations, where the wheel-rail contact is modelled according to the Hertzian contact theory together with Kalker’s simplified theory (including the numerical algorithm FASTSIM). The results from the track-vehicle simulations serve as input to the wear calculations. When modelling rail wear Archard’s wear model has been used, including wear coefficients based on laboratory measurements. The measurements have been performed under dry conditions, so the wear coefficients under lubricated conditions (both natural and deliberate lubrication) are reduced by factors estimated by field observations. After the wear depth calculations the wear distribution is smoothed and the rail profile is updated. The simulation procedure continues with a new wear step as long as the desired tonnage is not attained. Four curves of Tvärbanan with different curve radii, ranging from 85 to 410 m, have beenstudied in this work. On three of the curves the high rail is deliberately lubricated, whereas no lubrication has been applied in the widest curve. The vehicle operating the light rail line is an articulated tram with two motor end bogies and one intermediate trailer bogie. The line was opened in August 1999 and extended in one direction one year later. Rail profile measurements have been carried out by SL since March 2002. The traffic tonnage at the selected sites from the opening of the line to the last measurement occasion (September2004) is at most 8.9 mega gross ton per track. The results of the rail wear prediction tool are evaluated by comparing worn-off area of the simulated rail profiles with that of the measured rail profiles. Simulated and measured resultsdo not agree too well, since the simulated rail wear is more extensive than the measured one, especially on the outer rail. However, the shapes of the simulated worn rail profiles are comparable to those of the measured rail profiles.QC 20101123
5
Kumar, Saurabh. "A study of the rail degradation process to predict rail breaks." Licentiate thesis, Luleå tekniska universitet, Drift, underhåll och akustik, 2006. http://urn.kb.se/resolve?urn=urn:nbn:se:ltu:diva-18226.
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Rail infrastructure is a large and costly investment, and has a long life. To realize the benefits from this investment, effective maintenance is required. Railways are one of the prime modes of transportation in many countries and as they are closely associated with passenger and cargo transportation, they own high risk in terms of potential loss of human life and damage/destruction of assets. New technologies and stringent safety standards are constantly being introduced, but accidents still occur. There will always be some risk associated with derailments and collisions, but it can be reduced by elimination of the root causes by means of an effective maintenance strategy to govern optimization of inspection, lubrication and grinding frequency and/or improvement in skill and efficiency. A detailed study of the defects which emerge both in the rolling stock and the rail infrastructure is essential to identify the correct maintenance strategy. Detection and rectification of rail defects/degradations are major issues for all rail players around the world. Some of the rail degradations include worn out rails, weld problems, internal defects, corrugations and rolling contact fatigue (RCF) initiated problems such as surface cracks, head checks, squats, spalling and shelling. If undetected and/or untreated, these defects can lead to rail breaks and derailments. Efficient maintenance strategies can reduce potential risk of rail breaks and derailments. A potential risk is the risk which accumulates in the form of rail degradation over a period of time. In spite of continuous efforts made by all rail infrastructure operators around the world to reduce costs, a substantial proportion of railway budget is spent on rail maintenance. It is understood that the consequential costs due to derailment reduces with increase in inspection, lubrication, grinding and replacement costs. The challenge is to find a balance between the maintenance costs which consists of inspection, lubrication and grinding costs, and consequential costs due to derailments. The consequences of derailment in terms of loss of human life, damage/destruction of assets and loss of company trust and reputation justify maintaining stringent safety standards, which require massive rail maintenance investments in order to be met. Reduction in maintenance investments may increase the rate of rail degradation, which may increase the risk of derailments. The aim is to develop an approach to predict rail failures, which will help to optimize maintenance activities (inspection, grinding, rectification/replacement and/or welding). Generally, there is a trade-off between maintenance investment and the risk involved in rail degradation in order to develop a rail maintenance procedure. Failure prediction of rail sections undergoing degradation will help to estimate the risk of derailment. Thus, prediction of the rail failure rate is a requirement for the development of an effective rail maintenance procedure. Different types of rail degradation processes leading to various rail defects have been studied. The performed literature studies indicate a need for better prediction of rail failure over a period of time based on the factors influencing rail degradation. The maintenance strategy followed by the Swedish National Rail Administration (Banverket), Sweden's rail infrastructure operator, is described and the issues related to rail degradation and maintenance are outlined for further research in this area. Rail failure data has been extracted from different Banverket's databases, classified according to a classification framework developed and analyzed over a period of time based on Million Gross Tonnes (MGT) of traffic using Weibull distribution. During the process of data evaluation and analysis, a method of extracting useful information from incomplete data has been identified.Godkänd; 2006; 20061212 (ysko)
6
Pang, Tao, and tony_pang@hotmail com. "Studies on Wheel/Rail Contact Impact Forces at Insulated Rail Joints." Central Queensland University. Centre for Railway Engineering, 2008. http://library-resources.cqu.edu.au./thesis/adt-QCQU/public/adt-QCQU20080410.154708.
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To investigate the wheel/rail contact impact forces at insulated rail joints (IRJs), a three-dimensional finite element model and strain gauged experiments are employed and reported in this thesis. The 3D wheel/rail contact-impact FE model adopts a two-stage analysis strategy in which the wheel-IRJ railhead contact is first established in the static analysis and the results transferred to dynamic analysis for impact simulations. The explicit FE method was employed in the dynamic analysis. The Lagrange Multiplier method and the Penalty method for contact constraint enforcement were adopted for the static and dynamic analyses respectively.
The wheel/rail contact-impact in the vicinity of the end post is exhibited via numerical examples from the FE modelling. The wheel/rail contact impact mechanism is investigated. The strain gauged experiments which consist of a lab test and a field test are reported. The signature of the strain time series from the field test demonstrates a plausible record of the dynamic responses due to the wheel/rail contact impact. By using the experimental data, both the static and the dynamic FE models are validated.
It is found that the stiffness discontinuity of the IRJ structure causes a running surface geometry discontinuity during the wheel passages which then causes the impact in the vicinity of the end post. Through a series of sensitivity studies of several IRJ design parameters, it is shown that the IRJ performance can be effectively improved with optimised design parameters.
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Murty, Anjali. "Highly linear, rail-to-rail ICMR, low voltage CMOS operational amplifer." Thesis, Georgia Institute of Technology, 1998. http://hdl.handle.net/1853/14884.
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Morris, John D. (John David) 1978. "Improving toggle rate in a rail-to-rail comparator output stage." Thesis, Massachusetts Institute of Technology, 2001. http://hdl.handle.net/1721.1/16854.
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Thesis (M.Eng.)--Massachusetts Institute of Technology, Dept. of Electrical Engineering and Computer Science, 2001.Includes bibliographical references.
This electronic version was submitted by the student author. The certified thesis is available in the Institute Archives and Special Collections.
The demand for high-speed components has driven an increase in the speed of analog comparators, a building block for many analog circuits. This paper describes the modification of one of Linear Technology's low-cost, high-speed comparators to increase the output toggle rate beyond the one hundred megahertz range. The essential modifications to the output stage mainly relate to overcoming quasi-saturation of the output devices by extracting unwanted, stored base charge. Additional features were added into a dual comparator package with a tiny footprint to increase consumer interest and to diversify it from other comparators in Linear Technology's line. A final circuit design and physical silicon layout were designed using computer design tools, and the IC was fabricated and tested. The first silicon was tested extensively and worked successfully with only minor undesired discrepancies that were deemed acceptable. The LT1715 design was successful since the design itself accomplished all the desired specifications and the part is now available for sale.
by John D. Morris.
M.Eng.
9
Naini, Srikar Reddy. "PING-PONG AUTO-ZERO AMPLIFIER WITH RAIL-TO-RAIL OUTPUT BUFFER." University of Akron / OhioLINK, 2018. http://rave.ohiolink.edu/etdc/view?acc_num=akron1537224512595497.
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McNeal, Cedric J. "Barrel wear reduction in rail guns : the effects of known and controlled rail spacing on low voltage electrical contact and the hard chrome plating of copper-tungsten rail and pure copper rails /." Thesis, Monterey, Calif. : Springfield, Va. : Naval Postgraduate School ; Available from National Technical Information Service, 2003. http://library.nps.navy.mil/uhtbin/hyperion-image/03Jun%5FMcNeal.pdf.
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Thesis (M.S. in Applied Physics)--Naval Postgraduate School, June 2003.Thesis advisor(s): William B. Maier II, Richard Harkins. Includes bibliographical references (p. 45-46). Also available online.
11
Lundmark, Jonas. "Rail grinding and its impact on the wear of wheels and rails." Licentiate thesis, Luleå : Luleå University of Technology, 2007. http://epubl.ltu.se/1402-1757/2007/37/index.html.
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Telliskivi, Tanel. "Wheel-rail Interaction Analysis." Doctoral thesis, KTH, Machine Design, 2003. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-3532.
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A general approach to numerically simulating wear in rollingand sliding contacts is presented in this thesis. A simulationscheme is developed that calculates the wear at a detailedlevel. The removal of material follows Archards wear law,which states that the reduction of volume is linearlyproportional to the sliding distance, the normal load and thewear coefficient. The target application is the wheel-railcontact.
Careful attention is paid to stress properties in the normaldirection of the contact. A Winkler method is used to calculatethe normal pressure. The model is calibrated either withresults from Finite Element simulations (which can include aplastic material model) or a linear-elastic contact model. Thetangential tractions and the sliding distances are calculatedusing a method that incorporates the effect of rigid bodymotion and tangential deformations in the contact zone.Kalkers Fastsim code is used to validate the tangentialcalculation method. Results of three different sorts ofexperiments (full-scale, pin-on-disc and disc-on-disc) wereused to establish the wear and friction coefficients underdifferent operating conditions.
The experimental results show that the sliding velocity andcontact pressure in the contact situation strongly influencethe wear coefficient. For the disc-on-disc simulation, therewas good agreement between experimental results and thesimulation in terms of wear and rolling friction underdifferent operating conditions. Good agreement was alsoobtained in regard to form change of the rollers. In thefull-scale simulations, a two-point contact was analysed wherethe differences between the contacts on rail-head to wheeltread and rail edge to wheel flange can be attributed primarilyto the relative velocity differences in regard to bothmagnitude and direction. Good qualitative agreement was foundbetween the simulated wear rate and the full-scale test resultsat different contact conditions.
Keywords:railway rail, disc-on-disc, pin-on-disc,Archard, wear simulation, Winkler, rolling, sliding
13
Jilabi, Abdulsameea. "Welding of rail steels." Thesis, University of Manchester, 2015. https://www.research.manchester.ac.uk/portal/en/theses/welding-of-rail-steels(b9d907ef-45fc-4649-8c2f-9239a121abe0).html.
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The worldwide preferred method for rail joining is welding; flash butt welding (FBW) and thermite welding (TW) are the two main welding methods used for joining continuous welded rail (CWR) tracks. However, the welds still represent a discontinuity in the track structure due to variations in microstructure, mechanical properties and residual stress levels with respect to the parent rail. These variations can play significant roles in increasing the risk of weld failure under service conditions. In order to better understand how FBW parameters affect these variations, the two main parameters; number of preheating cycles and upsetting forces were varied in three 56E1 rail welds, welded by a stationary FBW machine. Besides, these variations were systematically compared with those that occur in a standard thermite 60E2 rail weld. The thermite weld showed a heat affected zone (HAZ) extent much greater than those measured in the flash butt welds. The flash butt rail weld with a greater upsetting force (Standard Crushed) showed a HAZ extent larger than those in the other two welds (Standard Uncrushed and Narrow-HAZ Crushed), while the weld with fewer preheating cycles (Narrow-HAZ Crushed) showed a smaller extent of the HAZ.All welds showed pearlite colonies with proeutectoid ferrite at the prior austenite grain boundaries in the weld centre, and in the thermite weld zone. The rest zones across the welds exhibited almost fully pearlitic microstructures, but the pearlite at nearly the visible HAZ extents was partially spheroidised. The partially spheroidization zone had the minimum hardness across each of the thermite and flash butt welds. The Narrow-HAZ Crushed weld showed hardness in the weld centre, on average, higher than that of the parent metal. Moreover, the averaged hardness levels in this weld were significantly higher than those in the other two welds. However, these levels in the Standard Crushed weld were slightly lower than those in the Standard Uncrushed weld. Although the visible HAZ extent coincided with the point of minimum hardness, the residual stresses arising from the welds seem to extend much further. Contour Method and laboratory X-ray diffraction techniques were used together to measure the residual stress components across the thermite and flash butt rail welds. The longitudinal residual stress distribution showed tension in the web region along with compression in the head and foot regions of the rail welds. The vertical stress distribution across the flash butt welds was generally similar, and the maximum tensile stress values were comparable to those in the longitudinal direction. While the maximum values of the longitudinal tensile stress increased with decreasing the HAZ widths, these values in the vertical direction were significantly unaffected. However, the longitudinal and vertical tensile residual stresses typically promote the vertical straight-break and horizontal split web failure modes respectively.
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Kawasaki, Junji 1968. "Estimations of rail irregularities." Thesis, Massachusetts Institute of Technology, 2001. http://hdl.handle.net/1721.1/8543.
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Thesis (S.M.)--Massachusetts Institute of Technology, Dept. of Mechanical Engineering, 2001.Includes bibliographical references (leaves 74-76).
Inspection cars that have been used to measure rail irregularities are costly and need operators. This thesis proposes a method to estimate rail irregularities by measuring accelerations of a passenger car instead of direct measurement by using a conventional inspection car. Using a System Identification technique and data obtained by simulations based on a three-dimensional rail vehicle model with actual rail irregularities, the proposed method identifies an inverse system where inputs are accelerations of a vehicle and outputs are rail irregularities. The resulting model is assessed through comparing the estimated irregularity with the actual irregularity. Validation results show that the estimate agree well with the actual irregularity for the Vertical Irregularity. Though the estimation error for the Lateral Irregularity is larger than that for the Vertical Irregularity, the error is acceptable form a practical point of view. The quality of the estimation is evaluated quantitatively by using the Mean Square Error. In addition, resolution of the estimation is presented in order to demonstrate the accuracy of the estimation. Model uncertainties are assessed for a practical implementation. The effects due to two major uncertainties, mass variations and speed variations, are evaluated by using the Singular Value Decomposition in order to present the limitations of the estimation using a nominal model. In addition, this thesis proposes a compensation method for mass variations and speed variations.
by Junji Kawasaki.
S.M.
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Ray, Arunim. "Niobium microalloyed rail steels." Thesis, University of Cambridge, 2017. https://www.repository.cam.ac.uk/handle/1810/265387.
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Rail steels rely primarily on possessing adequate wear and rolling contact fatigue resistance. These properties, together with the toughness, can in principle be optimized by implementing thermomechanical processing assisted by controlled niobium additions. The purpose of the current work is to develop a Nb-microalloying strategy in the context of high-carbon pearlitic and cementite-free bainitic steels. The conventional methods do not leave the critical regions of a rail section in a suitably processed state. An attempt has been made for the first time, to create a pancaked austenite grain structure, with an examination of the consequences on the final product. One of the major difficulties is to ensure that niobium does not segregate during manufacturing, since niobium is a strong carbide former and rail steels traditionally contain large carbon concentrations. Niobium solubility in austenite has been assessed critically and thermodynamic calculations for microsegregation have been taken into account. The aim is to ensure that any primary niobium carbide precipitated from solute-enriched liquid during non-equilibrium solidification, can be taken into solution in austenite during reheating, to mitigate potential effects of coarse precipitates on the final mechanical properties. Rail steels containing 0.01-0.02 wt% Nb have been designed and characterised. In as-cast condition, primary niobium carbides as large as ~10 µm can be observed, which dissolve slowly during reheating. An attempt has been made to develop a model to estimate the dissolution kinetics of the carbides. Dissolved niobium in reheated austenite precipitates during hot deformation as fine niobium carbides (< 50 nm) which inhibit austenite recrystallisation by pinning the austenite grain boundaries. Nb-microalloying increases the ‘no-recrystallisation temperature’ of deformed austenite during multi-pass compression tests. The topology of grain deformation has been analysed in terms of stereological calculations and dilatometric experiments have shown that transformation kinetics tend to accelerate when the austenite is deformed below the no-recrystallisation temperature, however the effect is relatively small. The microstructure and mechanical properties of the as-rolled Nb-microalloyed steels have been characterised along with their rolling-sliding wear performance and compared with their non-microalloyed counterparts. Increased austenite grain boundary area and increased dislocation activity due to pancaking, hinder bainite growth which leads to an increased retained austenite volume fraction. This in turn, leads to slightly improved ductility, improved toughness and improved wear resistance in Nb-microalloyed bainitic alloys. Microstructural refinement in Nbmicroalloyed pearlitic alloys does not have any significant effect on tensile and toughness properties, but wear resistance improves significantly. A Bayesian neural network model has been developed to estimate the wear of rails. Predicted trends have been found consistent with metallurgical experience and the perceived noise levels are consistent with reasonable repeatability of the wear testing method used. The model can be applied widely to estimate wear because of its capacity to indicate uncertainty, including both the perceived level of noise in the output, and an uncertainty associated with fitting the function in the local region of input space.
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Vieira, Filipe Costa Beber. "Amplificador de Instrumentação em Modo Corrente com entrada e saída Rail-to-Rail." Universidade Federal de Santa Maria, 2009. http://repositorio.ufsm.br/handle/1/5347.
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This dissertation is aimed at the development of a current mode instrumentation amplifier (CMIA) with a high common mode input range. This characteristic is obtained due
to the rail-to-rail operational amplifiers (opamps). These opamps are built with rail-to-rail differential amplifiers as input stages, and with cascode-based output stages, which are able to copy its current by adding identical branches and connecting their gates without the voltage
degradation as the known CMIA topologies. The main contribution of this work is the development of a rail-to-rail current mode instrumentation amplifier, analyzing the pros and cons of this topology. The functionality of the proposed topology is shown through measured results of a manufactured integrated circuit. This first prototype, although it was operated in a large input common mode range, presented insufficient values of CMRR (Common Mode
Rejection Ratio) and VOS (Offset voltage). These two characteristics were studied and modeled, the instrumentation amplifier was re-designed, and simulated results demonstrate important improvements.Esta dissertação tem como objetivo o desenvolvimento de um amplificador de instrumentação em modo corrente com uma ampla faixa de entrada em modo comum. Esta característica é obtida graças ao emprego de estágios de amplificação rail-to-rail na entrada e a geração do sinal de saída através do espelhamento da corrente diretamente dos gates dos transistores do estágio ao invés da alternativa clássica, onde espelhos são ligados em série e degradam a excursão do sinal de saída. Com esta proposta, é possível a implementação de ampops com entrada e saída rail-to-rail. A principal contribuição deste trabalho é analisar as vantagens e desvantagens da utilização destas soluções na implementação de um amplificador de instrumentação com entrada rail-to-rail. A funcionalidade da topologia proposta é demonstrada através dos resultados medidos de um circuito integrado fabricado. Este primeiro protótipo, apesar do bom funcionamento em toda a faixa de entrada em modo comum, apresentou valores insatisfatórios de CMRR (Common Mode Rejection Ratio) e de VOS (Tensão de offset), o que levou a um aprofundamento no estudo e modelagem destas características. A partir disto, o circuito foi re-projetado e os resultados de simulação demonstram melhorias bastante significativas em suas características.
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Sakurai, Satoshi. "Design of rail-to-rail CMOS operational amplifiers for a 3-V supply /." The Ohio State University, 1994. http://rave.ohiolink.edu/etdc/view?acc_num=osu1487854314870488.
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Al-Tony, Fa. "The marginal social cost of road and rail : implications for rail investment and pricing." Thesis, Cranfield University, 1995. http://dspace.lib.cranfield.ac.uk/handle/1826/3862.
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An important issue for transport policy is whether more investment should be devoted to rail schemes and less to road schemes and vice versa. This raises the problem of comparing the returns from investments in the two modes currently assessed on a different basis - road schemes are appraised on a Cost Benefit Analysis (CBA) basis, whereas rail schemes are assessed on a Financial Analysis (FA). This study is a step in the direction of identifying the difference between the two techniques (CBA and FA) of appraisal in general and in case of rail investment in particular, and examining the implications of the use of the two different techniques in assessing the investment in road and rail. In addition, the study develops a methodology for assessing rail investment schemes that could be consistent with the cost benefit analysis being used in assessing road investment projects. The differences between CBA and FA are identified. The current practice of assessing road and rail investment schemes is examined and the weaknesses are outlined. The potential implications of assessing road and rail investment on different criteria are explored. Previous rail investment studies where both CBA and FA were undertaken are reviewed and discussed to explore how the task of CBA were carried out to rail schemes and to show the difference with the current study approach. The study framework of rail scheme appraisal is identified to include four elements of impacts. These are; financial impacts to the rail operator (producer surplus), rail user benefits (consumer surplus), non-user benefits, and other impacts on other bodies in the society (tax adjustments). Non-user benefits concerned by the study are road congestion time, noise, air pollution, accidents, and vehicle operating costs. Road congestion time, noise and air pollution are identified as externalities, while accidents and vehicle operating costs are dealt with as cases of cost misperception. The five items of non-user benefits are measured at the margin in a process to identify the Marginal Social Cost (MSC) of travel as a function of the road type alternative. Eight types of road are identified for the study to represent the entire UK road network. The measurement process of non-user benefits incorporates the variation in traffic over time and place. This is carried out by incorporating four traffic distributions in the calculation process. The distributions of traffic reflect traffic variations from hour to another (24 hours) throughout the day, from day to another (7 days) throughout the week, from month to another (12 months) throughout the year and from location to another throughout the UK entire road network. The implications of the study findings are explored. Three undesirable implications are identified. These are welfare losses to the society, lower share for rail travel, and investment bias towards roads. Three policy options are put as a solution. These are, pricing road and rail services according to the MSC, subsidising public transport, and applying a consistent appraisal method for road and rail investment. The contribution of these options towards achieving a sustainable balance between road and rail as well as their applicability in practice are examined. At the end some improvements and attached areas of further research are suggested.
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Al-Tony, Fathy El-Sayed. "The marginal social cost of road and rail: Implications for rail investment and pricing." Thesis, Cranfield University, 1995. http://hdl.handle.net/1826/3862.
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An important issue for transport policy is whether more investment should be devoted
to rail schemes and less to road schemes and vice versa. This raises the problem of
comparing the returns from investments in the two modes currently assessed on a
different basis
- road schemes are appraised on a Cost Benefit Analysis (CBA) basis,
whereas rail schemes are assessed on a Financial Analysis (FA).
This study is a step in the direction of identifying the difference between the two
techniques (CBA and FA) of appraisal in general and in case of rail investment in
particular, and examining the implications of the use of the two different techniques in
assessing the investment in road and rail. In addition, the study develops a
methodology for assessing rail investment schemes that could be consistent with the
cost benefit analysis being used in assessing road investment projects.
The differences between CBA and FA are identified. The current practice of assessing
road and rail investment schemes is examined and the weaknesses are outlined. The
potential implications of assessing road and rail investment on different criteria are
explored. Previous rail investment studies where both CBA and FA were undertaken
are reviewed and discussed to explore how the task of CBA were carried out to rail
schemes and to show the difference with the current study approach.
The study framework of rail scheme appraisal is identified to include four elements of
impacts. These are; financial impacts to the rail operator (producer surplus), rail user
benefits (consumer surplus), non-user benefits, and other impacts on other bodies in
the society (tax adjustments). Non-user benefits concerned by the study are road
congestion time, noise, air pollution, accidents, and vehicle operating costs. Road
congestion time, noise and air pollution are identified as externalities, while accidents
and vehicle operating costs are dealt with as cases of cost misperception.
The five items of non-user benefits are measured at the margin in a process to identify
the Marginal Social Cost (MSC) of travel as a function of the road type alternative.
Eight types of road are identified for the study to represent the entire UK road
network. The measurement process of non-user benefits incorporates the variation in
traffic over time and place. This is carried out by incorporating four traffic
distributions in the calculation process. The distributions of traffic reflect traffic
variations from hour to another (24 hours) throughout the day, from day to another (7
days) throughout the week, from month to another (12 months) throughout the year
and from location to another throughout the UK entire road network.
The implications of the study findings are explored. Three undesirable implications
are identified. These are welfare losses to the society, lower share for rail travel, and
investment bias towards roads. Three policy options are put as a solution. These are,
pricing road and rail services according to the MSC, subsidising public transport, and
applying a consistent appraisal method for road and rail investment. The contribution
of these options towards achieving a sustainable balance between road and rail as well
as their applicability in practice are examined. At the end some improvements and
attached areas of further research are suggested.
20
Vellturo, Christopher Allan. "The deregulation of the U.S. rail industry : efficiency and equity in attaining rail viability." Thesis, Massachusetts Institute of Technology, 1989. http://hdl.handle.net/1721.1/14279.
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Lacerda, Fabio de. "Projeto de um amplificador operacional CMOS de baixa tensão do tipo rail-to-rail." [s.n.], 2001. http://repositorio.unicamp.br/jspui/handle/REPOSIP/260130.
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Orientador: Carlos Alberto dos Reis FilhoDissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Engenharia Eletrica e de Computação
Made available in DSpace on 2018-08-01T07:37:16Z (GMT). No. of bitstreams: 1 Lacerda_Fabiode_M.pdf: 2622408 bytes, checksum: 2f4c944421ef4f76580a3a2d600b57cf (MD5) Previous issue date: 2001
Mestrado
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Lacerda, Fábio de, and Instituto de Engenharia Nuclear. "Projeto de um amplificador operacional CMOS de baixa tensão do tipo rail-to-rail." Instituto de Engenharia Nuclear, 2001. http://carpedien.ien.gov.br:8080/handle/ien/1906.
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Este trabalho descreve o procedimento de projeto de amplificadores operacionais em tecnologia CMOS. Para isto, foram objetos deste processo dois amplificadores com especificações distintas. O primeiro foi o amplificador canônico com compensação interna do tipo Miller, cujas especificações incluíram a tensão de alimentação de 3V, o ganho mínimo de malha aberta em baixas freqüências de 60dB e a freqüência de ganho unitário de 4MHz para uma carga externa de 10kΩ em paralelo com 10pF. O segundo, já aplicando o aprendizado que resultou do primeiro, foi um amplificador operacional do tipo rail-to-rail na entrada e na saída, com especificações mais exigentes: tensão de alimentação de 3V, ganho mínimo de malha aberta em baixas freqüências de 80dB e freqüência de ganho unitário de 10MHz para carga externa de 10kΩ em paralelo com 10pF. Os resultados obtidos a partir de protótipos fabricados em tecnologia CMOS de 0,8µm para o primeiro amplificador e 0,6µm para o segundo foram bastante próximos às especificações. Por exemplo, as excursões de entrada e de saída do segundo amplificador mostraram-se perfeitamente compatíveis com amp-ops rail-to-rail típicos enquanto as demais características medidas confirmaram que o procedimento de projeto adotado foi bastante adequado.
This dissertation describes the process of designing operational amplifiers in CMOS technology. To accomplish this, the author focused on two amplifiers with distinct specifications. The first one was the canonical amplifier with internal Miller compensation, whose specifications included the nominal power supply of 3V, minimum open-loop low-frequency gain of 60dB and unity-gain frequency of 4MHz driving an external load of 10kΩ in parallel with 10pF. The second one, exploiting the experience obtained from the previous amplifier, was an operational amplifier with rail-to-rail input and output with more rigorous specifications: 3V power supply, minimum open-loop low-frequency gain of 80dB and 10MHz unity-gain frequency driving an external load of 10kΩ in parallel with 10pF. Prototypes of the canonical amplifier were fabricated in 0.8µm CMOS technology while the rail-to-rail amplifier was implemented in 0.6µm CMOS technology. Experimental results were in very good agreement with the specifications. For example, input and output signal swings from the second amplifier proved to be fully compatible with typical rail-to-rail op-amps while the remaining characteristics confirmed that the design process was very adequate.
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Pratikakis, Nikolaos. "Mathematical modeling of rail gun." Thesis, Monterey, Calif. : Springfield, Va. : Naval Postgraduate School ; Available from National Technical Information Service, 2006. http://library.nps.navy.mil/uhtbin/hyperion/06Sep%5FPratikakis.pdf.
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Thesis (M.S. in Mechanical Engineering)--Naval Postgraduate School, September 2006.Thesis Advisor(s): Kwon Young. "September 2006." Includes bibliographical references (p. 77-78). Also available in print.
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Uff, Jamie Colin. "Rail corridor asset mapping system." Thesis, University of Newcastle Upon Tyne, 2009. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.492083.
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This thesis presents a novel approach for locating rail infrastructure to a precision required for effective asset management. A new or improved survey system was required which was rapidly mobilised and non-disruptive to normal rail operations. To aid the designing of a new system research was carried out into contemporary surveying techniques, which were then assessed against key design criteria.
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Heunis, Johannes Jacobus. "Material models for rail pads." Thesis, Stellenbosch : University of Stellenbosch, 2011. http://hdl.handle.net/10019.1/6643.
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Thesis (MScEng (Mechanical and Mechatronic Engineering))--University of Stellenbosch, 2011.ENGLISH ABSTRACT: The vibrations and noise “pollution” that rail vehicles produce have become of particular concern in recent years. More pressure is being placed on operators of trains and trams (especially those operating in urban environments) to reduce their impact on neighbouring infrastructure. This project investigated the infrastructure available for vibration and noise mitigation and generated material models for some of the materials used in these types of rail infrastructure. The most common type of rail infrastructure used in South Africa is ballasted sleepers. Rail pads are sometimes used to reduce the transmitted vibration of these sleepers; this study focused on the materials used in the manufacture of these pads. Since most of these materials can be described as resilient/viscoelastic, the study of literature regarding these materials is essential within the scope of this project. Models found in literature were adapted by the addition of a non-linear stiffness element to account for the material behaviour at higher preloads. Three commercially available materials were tested and optimisation algorithms applied to determine their material coefficients (damping and stiffness), focusing on the preload and frequency dependency of these coefficients.
AFRIKAANSE OPSOMMING: Die vibrasie en geraas “besoedeling” wat spoor voertuie genereer het in die in die afgelope paar jare van kritieke belang geword. Meer druk word op operateurs van treine en trems geplaas (veral die operateurs met operasies in stedelike gebiede) om hulle impak op aangrensende infrastruktuur te verminder. Hierdie projek is dus daarop gemik om te bepaal watter infrastuktuur beskikbaar is vir die vermindering van vibrasie en geraas asook die ontwikkeling van materiaal modellle vir sommige van die materiale wat gebruik word in hierdie tipes van spoor infrastruktuur. Die mees algemene spoor infrastruktuur wat gebruik word in Suid-Afrika is dwarslêers met ballas. Spoor blokke word soms gebruik om die oordrag van vibrasies te verminder vir hierdie dwarslêers en daarom het hierdie studie fokus geplaas op die materiale wat gebruik word in die vervaardiging van hierdie blokke. Aangesien die meeste van hierdie materiale beskryf kan word as veerkragtig/visco, is 'n literatuurstudie oor hierdie materiale noodsaaklik binne die bestek van hierdie projek. Modelle wat gevind is in die literatuur is aangepas deur 'n nie-lineêre styfheids element by te voeg wat voorsiening maak vir die materiale se gedrag by hoër voorspannings. Drie algemene kommersieël beskikbare materiale is getoets en optimeringsprossesse is toegepas om hulle materiaal koëffisiënte (demping en styfheid) te bepaal met die klem geplaas op die voorspanning en frekwensie afhanklikheid van hierdie koëffisiënte.
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Baranger, Philippe. "Le rail aux etats-unis." Toulouse 2, 1991. http://www.theses.fr/1991TOU20069.
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Le chemin de fer s'est developpe a la meme epoque que la nation americaine. Avant la fin du dix-neuvieme siecle. Le reseau s'etait etendu a tout l'espace americain. Le nouveau systeme joua un role preeminent dans l'ascension des etats-unis sur le plan international les puissantes compagnies, qui etaient toutes des entreprises privees, servirent de laboratoires dans l'elaboration de nouvelles relations sociales et professionnelles, ainsi que dans la creation d'entreprises. Entre les deux guerres, le rail du ceder une part de son quasi-monopole du transfert interieur, au profit de deux nouveaux concurrents, l'air et la route. A l'epoque moderne, les chemins de fer ont du s'adapter a des conditions d'exercice modifiees, lais ils conservent leur puissance. Au cours de toutes ces annees, le rail a penetre l'esprit americain et apporte une imagerie capable d'exprimer de nouveaux concepts ou de donner a d'anciennes notions une forme nouvelle. Tant par son histoire que par l'eventail de symboles qu'il fournit, le chemin de fer americain a contribue de maniere significative a l'experience nationaleRailways developed at the same time as the american nation did. By the turn of the century, the rail network has spread across the continent. The new system was active in bringing the united states to prominent international status. The mighty railroads, all private ventures, were also a laboratory for the working out of new labour rules, social relationships and entrepreneurial achievements. In the interwar period, their near monopoly as an interior transportation system was challenged by the air and the highway, to which they had to yield some of their ground. In modern times, railroads have had to adjust to new rules, but they remain strong. Throughout those years, the railroad entered the american mind and became a medium to express new conceptions or to rephrase old ones both as history and as an array of cultural symbols, railways have contributed to the making of the national experience
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Lau, Kam-lung Darren. "A study of the residential development of the East Rail : implications to the West Rail /." View the Table of Contents & Abstract, 2006. http://sunzi.lib.hku.hk/hkuto/record/B38026144.
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Lau, Kam-lung Darren, and 劉錦龍. "A study of the residential development of the East Rail: implications to the West Rail." Thesis, The University of Hong Kong (Pokfulam, Hong Kong), 2006. http://hub.hku.hk/bib/B45009016.
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Ma, Qian. "Condition-based maintenance applied to rail freight car components : the case of rail car trucks." Thesis, Massachusetts Institute of Technology, 1997. http://hdl.handle.net/1721.1/42621.
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Beal, Rien. "A low voltage rail-to-rail operational amplifier with constant operation and improved process robustness." [Ames, Iowa : Iowa State University], 2009. http://gateway.proquest.com/openurl?url_ver=Z39.88-2004&rft_val_fmt=info:ofi/fmt:kev:mtx:dissertation&res_dat=xri:pqdiss&rft_dat=xri:pqdiss:1468063.
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Babenko, Pavel. "VISUAL INSPECTION OF RAILROAD TRACKS." Doctoral diss., University of Central Florida, 2009. http://digital.library.ucf.edu/cdm/ref/collection/ETD/id/4013.
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In this dissertation, we have developed computer vision methods for measurement of rail gauge, and reliable identification and localization of structural defects in railroad tracks. The rail gauge is the distance between the innermost sides of the two parallel steel rails. We have developed two methods for evaluation of rail gauge. These methods were designed for different hardware setups: the first method works with two pairs of unaligned video cameras while the second method works with depth maps generated by paired laser range scanners. We have also developed a method for detection of rail defects such as damaged or missed rail fasteners, tie clips, and bolts, based on correlation and MACH filters. Lastly, to make our algorithms perform in real-time, we have developed the GPU based library for parallel computation of the above algorithms. Rail gauge is the most important measurement for track maintenance, because deviations in gauge indicate where potential defects may exist. We have developed a vision-based method for rail gauge estimation from a pair of industrial laser range scanners. In this approach, we start with building a 3D panorama of the rail out of a stack of input scans. After the panorama is built, we apply FIR circular filtering and Gaussian smoothing to the panorama buffer to suppress the noise component. In the next step we attempt to segment the rail heads in the panorama buffer. We employ the method which detects railroad crossings or forks in the panorama buffer. If they are not present, we find the rail edge using robust line fit. If they are present we use an alternative way: we predict the rail edge positions using Kalman filter. In the next step, common to both fork/crossings conditions, we find the adjusted positions of rail edges using additional clustering in the vicinity of the edge. We approximate rail head surface by the third degree polynomial and then fit two plane surfaces to find the exact position of the rail edge. Lastly, using rail edge information, we calculate the rail gauge and smooth it with 1D Gaussian filter. We have also developed a vision-based method to estimate the rail gauge from a pair of unaligned high shutter speed calibrated cameras. In this approach, the first step is to accurately detect the rail in each of the two non-overlapping synchronous images from the two cameras installed on the data collection cart by building an edge map, and fitting lines into the edge map using the Hough transform, and detecting persistent edge lines using a history buffer. After railroad track parts are detected, we segment rails out to find rail edges and calculate the rail gauge. We have demonstrated how to apply Computer Vision methods (the correlation filters and MACH filters in particular) to find different types of railroad elements with fixed or similar appearance, like railroad clips, bolts, and rail plates, in real-time. Template-based approaches for object detection (correlation filters) directly compare gray scale image data to a predefined model or template. The drawback of the correlation filters has always been that they are neither scale nor rotation invariant, thus many different filters are needed if either scale or rotation change. The application of many filters cannot be done in real-time. We have succeeded to overcome this difficulty by using the parallel computation technology which is widely available in the GPUs of most advanced graphics cards. We have developed a library, MinGPU, which facilitates the use of GPUs for Computer Vision, and have also developed a MinGPU-based library of several Computer Vision methods, which includes, among others, an implementation of correlation filters on the GPU. We have achieved a true positive rate of 0.98 for fastener detection using implementation of MACH filters on GPU. Besides correlation filters, MinGPU include implementations of Lucas-Kanade Optical Flow, image homographies, edge detectors and discrete filters, image pyramids, morphology operations, and some graphics primitives. We have shown that MinGPU implementation of homographies speeds up execution time approximately 600 times versus C implementation and 8000 times versus Matlab implementation. MinGPU is built upon a reusable core and thus is an easily expandable library. With the help of MinGPU, we have succeeded to make our algorithms work in real-time.Ph.D.
School of Electrical Engineering and Computer Science
Engineering and Computer Science
Computer Science PhD
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Reddy, Venkatarami. "Development of an integrated model for assessment of operational risks in rail track." Thesis, Queensland University of Technology, 2007. https://eprints.qut.edu.au/16488/1/Venkatarami_Reddy_Thesis.pdf.
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In recent years there has been continuous increase of axle loads, tonnage, train speed, and train length which has increased both the productivity in the rail sector and the risk of rail breaks and derailments. Rail operating risks have been increasing due to the increased number of axle passes, sharper curves, wear-out of rails and wheels, inadequate rail-wheel grinding and poor lubrication and maintenance. Rolling contact fatigue (RCF) and wear are significant problems for railway companies. In 2000, the Hatfield accident in the UK killed 4 people, injured 34 people and led to the cost of £ 733 million (AUD$ 1.73 billion) for repairs and compensation. In 1977, the Granville train disaster in Australia killed 83 people and injured 213 people. These accidents were related to rolling contact fatigue, wear and poor maintenance.
Studies on rail wear and lubrication, rolling contact fatigue and inspection and rail grinding analyse and assess the asset condition to take corrective and preventive measures for maintaining reliability and safety of rail track. Such measures can reduce the operational risks and the costs by early detection and prevention of rail failures, rail breaks and derailments. Studies have so far been carried out in isolation and have failed to provide a practical solution to a complex problem such as rail-wheel wearfatigue-lubrication-grinding-inspection for cost effective maintenance decisions. Therefore, there is a need to develop integrated economic models to predict expected total cost and operational risks and to make informed decisions on rail track maintenance.
The major challenges to rail infrastructure and rolling stock operators are to:
1. keep rolling contact fatigue and rail-wheel wear under controllable limits,
2. strike a balance between rail grinding and rail lubrication, and
3. take commercial decisions on grinding intervals, inspection intervals, lubrication placements, preventive maintenance and rail replacements.
This research addresses the development and analysis of an integrated model for assessment of operational risks in rail track. Most significantly, it deals with problems associated with higher axle loads; wear; rolling contact fatigue; rail defects leading to early rail replacements; and rail breaks and derailments. The contribution of this research includes the development of:
failure models with non-homogenous Poisson process and estimation of parameters.
economic models and analysis of costs due to grinding, risks, downtime, inspection and replacement of rails for 23, 12, 18 and 9 Million Gross Tonnes (MGT) of traffic through curve radius 0-300, 300-450, 450-600 and 600-800 m; and application of results from this investigation to maintenance and replacement decisions of rails. Cost savings per meter per year are:
* 4.58% with 12 MGT intervals compared to 23 MGT intervals for 0-300 m
* 9.63% with 12 MGT intervals compared to 23 MGT intervals for 300-450 m
* 15.80% with 12 MGT intervals compared to 23 MGT intervals for 450-600 m
* 12.29% with 12 MGT intervals compared to 23 MGT intervals for 600-800 m.
a lubrication model for optimal lubrication strategies. It includes modelling and economic analysis of rail wear, rail-wheel lubrication for various types of lubricators. Cost effectiveness of the lubricator is modelled, considering the number of curves and the total length of curves it lubricates. Cost saving per lubricator per year for the same curve length and under the same curve radius is:
* 17% for solar wayside lubricators compared to standard wayside lubricators.
simulation model for analysis of lubrication effectiveness. Cost savings per meter per year for:
* 12 MGT grinding interval is 3 times for 0-450 m and 2 times for 450-600 m curve radius with lubrication compared to without lubrication.
* 23 MGT grinding interval is 7 times for 0-450 m and 4 times for 450-600 m curve radius with lubrication compared to without lubrication.
a relative performance model, total curve and segment model.
an inspection model for cost effective rail inspection intervals. Cost savings per year for same track length, curves and MGT of traffic:
* 27% of total maintenance costs with two inspections, compared to one inspection considering risk due to rail breaks and derailments.
a risk priority number by combining probability of occurrence, probability of detection and consequences due to rail defects, rail breaks and derailments.
integrated model combining decisions on grinding interval, lubrication strategies, inspection intervals, rectification strategies and replacement of rails.
Cost saving per meter per year for 12 MGT is:
* 5.41% of total maintenance costs with two inspections, compared to one inspection considering risk due to rail breaks and derailments.
* 45.06% of total maintenance costs with lubrication for two inspections, compared to without lubrication.
Cost saving per meter per year for 23 MGT is:
* 5.61% of total maintenance costs with two inspections, compared to one inspection considering risk due to rail breaks and derailments.
* 68.68% of total maintenance costs with lubrication for two inspections, per year compared to no lubrication.
The thesis concludes with a brief summary of the contributions that it makes to this field and the scope for future research in wear-fatigue-lubrication-grinding-inspection for maintenance of rail infrastructure.
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Reddy, Venkatarami. "Development of an integrated model for assessment of operational risks in rail track." Queensland University of Technology, 2007. http://eprints.qut.edu.au/16488/.
Full textAbstract:
In recent years there has been continuous increase of axle loads, tonnage, train speed, and train length which has increased both the productivity in the rail sector and the risk of rail breaks and derailments. Rail operating risks have been increasing due to the increased number of axle passes, sharper curves, wear-out of rails and wheels, inadequate rail-wheel grinding and poor lubrication and maintenance. Rolling contact fatigue (RCF) and wear are significant problems for railway companies. In 2000, the Hatfield accident in the UK killed 4 people, injured 34 people and led to the cost of £ 733 million (AUD$ 1.73 billion) for repairs and compensation. In 1977, the Granville train disaster in Australia killed 83 people and injured 213 people. These accidents were related to rolling contact fatigue, wear and poor maintenance. Studies on rail wear and lubrication, rolling contact fatigue and inspection and rail grinding analyse and assess the asset condition to take corrective and preventive measures for maintaining reliability and safety of rail track. Such measures can reduce the operational risks and the costs by early detection and prevention of rail failures, rail breaks and derailments. Studies have so far been carried out in isolation and have failed to provide a practical solution to a complex problem such as rail-wheel wearfatigue-lubrication-grinding-inspection for cost effective maintenance decisions. Therefore, there is a need to develop integrated economic models to predict expected total cost and operational risks and to make informed decisions on rail track maintenance. The major challenges to rail infrastructure and rolling stock operators are to: 1. keep rolling contact fatigue and rail-wheel wear under controllable limits, 2. strike a balance between rail grinding and rail lubrication, and 3. take commercial decisions on grinding intervals, inspection intervals, lubrication placements, preventive maintenance and rail replacements. This research addresses the development and analysis of an integrated model for assessment of operational risks in rail track. Most significantly, it deals with problems associated with higher axle loads; wear; rolling contact fatigue; rail defects leading to early rail replacements; and rail breaks and derailments. The contribution of this research includes the development of: failure models with non-homogenous Poisson process and estimation of parameters. economic models and analysis of costs due to grinding, risks, downtime, inspection and replacement of rails for 23, 12, 18 and 9 Million Gross Tonnes (MGT) of traffic through curve radius 0-300, 300-450, 450-600 and 600-800 m; and application of results from this investigation to maintenance and replacement decisions of rails. Cost savings per meter per year are: * 4.58% with 12 MGT intervals compared to 23 MGT intervals for 0-300 m * 9.63% with 12 MGT intervals compared to 23 MGT intervals for 300-450 m * 15.80% with 12 MGT intervals compared to 23 MGT intervals for 450-600 m * 12.29% with 12 MGT intervals compared to 23 MGT intervals for 600-800 m. a lubrication model for optimal lubrication strategies. It includes modelling and economic analysis of rail wear, rail-wheel lubrication for various types of lubricators. Cost effectiveness of the lubricator is modelled, considering the number of curves and the total length of curves it lubricates. Cost saving per lubricator per year for the same curve length and under the same curve radius is: * 17% for solar wayside lubricators compared to standard wayside lubricators. simulation model for analysis of lubrication effectiveness. Cost savings per meter per year for: * 12 MGT grinding interval is 3 times for 0-450 m and 2 times for 450-600 m curve radius with lubrication compared to without lubrication. * 23 MGT grinding interval is 7 times for 0-450 m and 4 times for 450-600 m curve radius with lubrication compared to without lubrication. a relative performance model, total curve and segment model. an inspection model for cost effective rail inspection intervals. Cost savings per year for same track length, curves and MGT of traffic: * 27% of total maintenance costs with two inspections, compared to one inspection considering risk due to rail breaks and derailments. a risk priority number by combining probability of occurrence, probability of detection and consequences due to rail defects, rail breaks and derailments. integrated model combining decisions on grinding interval, lubrication strategies, inspection intervals, rectification strategies and replacement of rails. Cost saving per meter per year for 12 MGT is: * 5.41% of total maintenance costs with two inspections, compared to one inspection considering risk due to rail breaks and derailments. * 45.06% of total maintenance costs with lubrication for two inspections, compared to without lubrication. Cost saving per meter per year for 23 MGT is: * 5.61% of total maintenance costs with two inspections, compared to one inspection considering risk due to rail breaks and derailments. * 68.68% of total maintenance costs with lubrication for two inspections, per year compared to no lubrication. The thesis concludes with a brief summary of the contributions that it makes to this field and the scope for future research in wear-fatigue-lubrication-grinding-inspection for maintenance of rail infrastructure.
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Liu, Yat-ming. "External benefits and commuter rail development a case study of KCRC west rail and Tuen Mun /." Click to view the E-thesis via HKU Scholars Hub, 2006. http://lookup.lib.hku.hk/lookup/bib/B37938514.
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Block-Schachter, David. "Hysteresis and urban rail : the effects of past urban rail on current residential and travel choices." Thesis, Massachusetts Institute of Technology, 2012. http://hdl.handle.net/1721.1/73697.
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Thesis (Ph. D. in Transportation)--Massachusetts Institute of Technology, Dept. of Civil and Environmental Engineering, 2012.This electronic version was submitted by the student author. The certified thesis is available in the Institute Archives and Special Collections.
Cataloged from student-submitted PDF version of thesis.
Includes bibliographical references (p. 265-284).
Cities are endowed with and accumulate assets based on their unique histories, which in turn define the choice set of the present. These assets range from the natural-sheltered ports, fertile land--to the constructed--concrete and cement, institutions and people. This dissertation examines the effects of one of these assets, urban rail, on residential location and travel behavior, from the era of horsecars and streetcars to the present in Boston. It explores the hysteretical effects of past access to rail--the extent to which the urban system retains the impacts of rail even when it no longer exists. Current density and travel behavior are measurably influenced by past access to rail. The built environment and demographic patterns are found to be the strongest mechanism for these persistent effects. Past access to rail has shaped the city, and that shape has, in turn, affected travel behavior. For density and auto ownership there is an additional measurable effect of past access unexplained by the built environment or demographic patterns. This legacy is plausibly explained by cultural effects--mnemonics--due to personal history, behavioral norms, and zoning/politics. Past access to rail has a stronger effect on density than on auto ownership. The daily choice of modes is almost entirely conditioned on current circumstances. Because places shaped by rail retain its imprint, these findings imply that there is need to consider how policy decisions will influence the city's future choice set. The greatest benefits from the endowments of urban rail are likely where redevelopment costs are low and growth potential is high--particularly light industrial areas near strong central cities. Realizing these changes requires mechanisms that allow and encourage government and private entities to be patient with the long time frames for adaptation to rail infrastructure. One such step is requiring, rather than allowing, supportive zoning and other policies within the Federal Transit Administration's New Starts capital program--including such items as increased as-of-right density, reasonable limits on parking, car sharing, and graduated drivers licensing laws. This research strengthens prior findings that similar approaches can encourage sustainable cultural norms.
by David Block-Schachter.
Ph.D.in Transportation
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Archila, Téllez Andrés Felipe. "Intercity passenger rail productivity in the Northeast Corridor : implications for the future of high-speed Rail." Thesis, Massachusetts Institute of Technology, 2013. http://hdl.handle.net/1721.1/82340.
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Thesis (S.M. in Transportation)--Massachusetts Institute of Technology, Dept. of Civil and Environmental Engineering, 2013.Cataloged from PDF version of thesis.
Includes bibliographical references.
The ongoing discussion about the future implementation of high-speed rail (HSR) in the Northeast Corridor (NEC) is full of questions on the feasibility of HSR and the ability of Amtrak to implement it. Indeed, the introduction of the Acela Express in the past decade was not free from operating problems, but even with trains running below their full potential, the Amtrak NEC had substantial market growth. Thus, it is not clear if a true HSR service is feasible in the NEC, and if the current prospects are potentially effective. To evaluate the performance of the NEC and its main services in FY 2002-2012, and make inferences about HSR in the NEC for the next 30 years, we use productivity analysis. We employ a non-parametric single factor productivity (SFP) Törnqvist trans-log index approach with several metrics. We set ridership, revenue, revenue passenger-miles (RPM), and available seat-miles (ASM) as outputs, and operating costs as input. In this way, we provided guidelines and a robust structure of analysis that can be useful for subsequent passenger rail productivity studies. We find that the NEC experienced highly volatile, but considerable productivity growth in FY 2002-2012 (in the range of ~1-3% per year). Amtrak increased its ability to fill up and economically exploit the available capacity, but did not perform equally well on the supply side. Service changes, technical problems with train sets, targeted capital investments, and economic recession and recovery were the main drivers of productivity change. The Acela Express and Northeast Regional were very sensitive to external events, had large economies of scale, and implemented slow adjustment of capacity via rolling stock and infrastructure improvements, which varied depending on the service. The characteristics of the NEC reveal a potential for a successful introduction of HSR, but although Amtrak's Vision for HSR in the NEC is realistic (in terms of productivity), it is risky and perhaps the time scale is not ambitious enough. We recommend revising the current projections, incorporate additional planning approaches, accelerate key stages of the Vision and include the FAA in the planning process.
by Andrés Felipe Archila Téllez.
S.M.in Transportation
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Faiz, Rizwan Bin. "An empirical rail track degradation model based on predictive analysis of rail profile and track geometry." Thesis, Loughborough University, 2010. https://dspace.lboro.ac.uk/2134/6455.
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It is generally observed that the condition of rail tracks degrades rapidly over time until and unless effective maintenance is carried out. In the rail industry, rail maintenance actions are usually reactive, which means that maintenance is carried out after a defect has been identified. Unfortunately, this approach can lead to general safety concerns and may result in costly maintenance. Predictive maintenance, which aims to predict the future behaviour of track degradation based on the analysis of already recorded data, can be used to identify defects in advance, thus providing a solution for the above safety and cost concerns. Two important questions for which answers are sought in predictive maintenance of rail track are: where does the fault occur and when. The aim of the research presented in this thesis is to develop a novel predictive rail track degradation model that answers the above questions. The proposed model consists of an alignment component for effective alignment of data and a degradation component for understanding rail track degradation based on rail profile and track geometry parametric analysis. The thesis takes an incremental approach to data alignment proposing three different algorithms namely, distance alignment, fixed window based alignment and parameter based alignment. It is proven that the latter approach provides the most accurate data alignment algorithm. The degradation component of the proposed model is based on a comprehensive multivariate and univariate analysis. In multivariate analysis, parameters of a base file i.e. a file consisting of parameters belonging to the same segment of the rail track at a given time of measurement are predicted using all other parameters of the same file. In univariate analysis, every parameter of a given base file is predicted, temporally, from the corresponding parameters in the previous base files. Such contribution analysis manifests the level to which each parameter contributes in predicting other parameters and over time. Subsequent to univariate and iii multivariate analysis the predictive errors are thresholded into either exceedences i.e. they exceed the threshold line, needing immediate maintenance, or normal i.e. they are below the threshold line, needing no immediate maintenance. The research presented in this thesis shows that in multivariate analysis, rail profile parameters were predicted with 97% prediction accuracy below threshold, whereas track geometry parameters were predicted with 99% prediction accuracy below threshold. Both univariate and multivariate analysis will serve as the basis in monitoring track conditions and thus finding track degradation problems. This will greatly aid in planning predictive track degradation by providing an objective means of evaluating track conditions and hence the over all life of the rail track will increase.
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Bussieck, Michael. "Optimal lines in public rail transport." [S.l. : s.n.], 1998. http://deposit.ddb.de/cgi-bin/dokserv?idn=955665965.
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Ileri, Yetkin. "Dray Optimization in Truck/Rail Networks." Diss., Georgia Institute of Technology, 2007. http://hdl.handle.net/1853/13968.
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Daily drayage operations involve moving loaded or empty equipment between customer locations and rail ramps. Drayage orders are generally pickup and delivery requests with time windows. The repositioning of empty equipment may also be required in order to facilitate loaded movements. The drayage orders are satisfied by a heterogeneous fleet of drivers. Driver routes must satisfy various operational constraints.
In the first part of the dissertation, our goal is to minimize the cost of daily drayage operations in a region on a given day. We present an optimization methodology for finding cost-effective schedules for regional daily drayage operations. The core of the formulation is a set partitioning model whose columns represent routes. Routes are added to the formulation by column generation. We present numerical results for real-world data which demonstrate that our methodology produces low cost solutions in a reasonably short time.
The second part of the dissertation addresses minimizing total empty mileage when driver capacity is not restrictive and new orders are added to the problem in an online fashion. We present a lower bound for the worst case guarantee of any deterministic online algorithm. We develop a solution methodology and provide results for the performance of different scheduling policies and parameters in a simulated environment.
In the third part of the dissertation, we study a system with one rail ramp and one customer location which is served by a single driver. The problem has discrete time periods and at most one new order is released randomly each time period. The objective is to maximize the expected number of orders covered. With this simple problem, we seek to learn more about route planning for a single driver under uncertainty. We prove that carrying out an order ready to be picked up at the driver's current location is optimal for the case with one customer location. We show that the structure of the optimal policies is not simple and depends on various parameters. We devise a simple policy which yields provably near-optimal results and identify a case for which that policy is optimal.
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Armstrong, John. "Rail journey recovery following an incident." Thesis, University of Southampton, 2005. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.417984.
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Haberland, Heiner. "Empfindlichkeitsanalyse an einem Common-Rail-Einspritzsystem /." Düsseldorf : VDI-Verl, 2007. http://bvbr.bib-bvb.de:8991/F?func=service&doc_library=BVB01&doc_number=015964521&line_number=0001&func_code=DB_RECORDS&service_type=MEDIA.
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Zhu, Yi. "Adhesion in the wheel-rail contact." Doctoral thesis, KTH, Tribologi, 2013. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-133342.
Full textAbstract:
To attract more customers and compete with other modes of transportation, railway transport needs to ensure safety, punctuality, high comfort, and low cost; wheel–rail adhesion, i.e., the transmitted tangential force in the longitudinal direction during driving and braking, plays an important role in all these aspects. Adhesion needs to be kept at a certain level for railway operation and maintenance. However, wheel−rail contact is an open system contact. Different contaminants can present between the wheel and rail surfaces, forming a third-body layer that affects the adhesion. Prediction of wheel–rail adhesion is important for railway operations and research into vehicle dynamics; however, this prediction is difficult because of the presence of contaminants. This thesis deals with wheel–rail adhesion from a tribological perspective. The five appended papers discuss wheel–rail adhesion in terms of dry conditions, lubricated conditions, leaf contamination, iron oxides, and environmental conditions. The research methodologies used are numerical modelling, scaled laboratory experiments, and field tests. The research objective is to understand the mechanisms of the adhesion loss phenomenon. A numerical model was developed to predict wheel–rail adhesion based on real measured 3D surfaces. Computer simulation indicates that surface topography has a larger impact on lubricated than on dry contacts. Plastic deformation in asperities is found to be very important in the model. Ball-on-disc tests indicate that water can give an extremely low adhesion coefficient on smooth surfaces, possibly due to surface oxidation. Investigation of lubricated contacts at low speed indicates that oil reduces the adhesion coefficient by carrying a normal load, while adhesion loss due to water depends on the surface topography, water temperature, and surface oxidation. A field investigation indicates that leaves reduce the friction coefficient because of the chemical reaction between leaves and bulk materials. The thickness of the surface oxide layer was found to be an essential factor determining adhesion reduction. Pin-on-disc experiments found a transition in the friction coefficient with regard to the relative humidity, due to a trade-off between the water molecule film and the hematite on the surface.QC 20131031
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Hesse, Daniel. "Rail inspection using ultrasonic surface waves." Thesis, Imperial College London, 2007. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.444161.
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Mekonnen, Demsachew. "Addis Light Rail Transit - Travel Advisor." Thesis, Mittuniversitetet, Avdelningen för informations- och kommunikationssystem, 2015. http://urn.kb.se/resolve?urn=urn:nbn:se:miun:diva-25707.
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In the current wave of economic instability, the world is witnessing significanteconomic progress in the sub-Saharan Africa. In this particular part of the worldamong the best performing developing economies, Ethiopia’s progress is con-sidered as an example for achievements in the region in last decade. The gov-ernment of Ethiopia believes in building huge infrastructures in the whole coun-try and especially in the economically vital geographies like the capital AddisAbaba. The project I have proposed aims to contribute to the smooth function-ing of the Addis Light Rail Transit after its launch. This bachelor’s thesis in-tends to design and develop an application based on the technology of web ser-vices for Internet and smart phone users. So the App updates data on the arrivalof a train on a particular station, in the case of unlikely delay the app informsthe users on new schedules. The application provides a functionality to searchfor available upcoming journeys and allows the customers to pay for the jour-ney from the device they are having on their hand. Finally, the project providesinsights on the usability of the implemented applications based on summativeevaluation technique.
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Perez-Unzueta, Alberto Javier. "Wear resistance of pearlitic rail steels." Thesis, University of Leicester, 1992. http://hdl.handle.net/2381/34812.
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Modern railway transportation has imposed severe work conditions on the track. Wear of rails has become an important and costly phenomenon. Recent developments in the manufacture of rail steels have refined the interlamellar spacing to produce harder and more wear resistant pearlitic steels. Despite better nominal properties shown by bainitic and martensitic steels, pearlitic steels have shown lower wear rates. The aim of this study is to explain the mechanisms for the wear performance by observing how the lamellar pearlitic microstructure adapts to the wear loading. Four pearlitic rail steels, with similar chemical composition but with different hardnesses and interlamellar spacings, have been examined. Wear tests have been performed under both pure sliding and rolling-sliding conditions, the latter designed to simulate track conditions. The worn surfaces and the plastically deformed subsurface regions have been examined by optical metallography and scanning electron microscopy. It was observed that the plastic deformation produced considerable fracturing and realignment of the hard cementite lamellae. The effect of these realignments on the surface was to present an increased area fraction of hard cementite lamellae to the surface. Thinner cementite lamellae, associated with low interlamellar spacings, were easier to blend before fracturing. A relationship between the bulk hardness (HV) and the reciprocal root of the mean true interlamellar spacing has been proposed for fully pearlitic steels. Wear rates were found to be a function of the original bulk hardness, rather than the increased hardness of the plastically deformed layers. Also, wear rates were reduced as hardness increased by reducing the interlamellar spacing. Pure sliding and rolling-sliding wear tests ranked the four steels correctly. Furthermore, qualitative comparisons between experimental wear rates and those obtained in-track trials show the same scale in reduction of wear with increased hardness.
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Morris, Christopher Robert. "Data integration in the rail domain." Thesis, University of Birmingham, 2018. http://etheses.bham.ac.uk//id/eprint/8204/.
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The exchange of information is crucial to the operation of railways; starting with the distribution of timetables, information must constantly be exchanged in any railway network. The slow evolution of the information environment within the rail industry has resulted in the existence of a diverse range of systems, only able to exchange information essential to railway operations. Were the cost of data integration reduced, then further cost reductions and improvements to customer service would follow as barriers to the adoption of other technologies are removed. The need for data integration has already been studied extensively and has been included in the UK industry's rail technical strategy however, despite it's identification as a key technique for improving integration, uptake of ontology remains limited. This thesis considers techniques to reduce barriers to the take up of ontology in the UK rail industry, and presents a case study in which these techniques are applied. Amongst the key barriers to uptake identified are a lack of software engineers with ontology experience, and the diverse information environment within the rail domain. Techniques to overcomes these barriers using software based tools are considered, and example tools produced which aid the overcoming of these barriers. The case study presented is of a degraded mode signalling system, drawing data from a range of diverse sources, integrated using an ontology. Tools created to improve data integration are employed in this commercial project, successfully combing signalling data with (simulated) train positioning data.
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Kashima, Takashi 1971. "Reliability-based optimization of rail inspection." Thesis, Massachusetts Institute of Technology, 2004. http://hdl.handle.net/1721.1/29388.
Full textAbstract:
Thesis (S.M.)--Massachusetts Institute of Technology, Dept. of Civil and Environmental Engineering, 2004.Includes bibliographical references (p. 123-126).
This thesis proposes a quantitative method to optimize inspection/repair intervention in rail defect management. Rail defect management is important for track maintenance, since rails are the most significant and basic component of the track systems. Rail inspection is a fundamental intervention to prevent rail failure. Railroads have evolved the rail inspection interval based on their empirical judgement and on field data. A crack size is predicted by linear elastic fracture mechanics (LEFM). The proposed method identifies the time-varying rail reliability due to deterioration, using data obtained from LEFM and from first-order reliability methods (FORM), which consider the uncertainty regarding the model. Since FORM is an approximation method, Monte Carlo simulation confirms the results. To represent practical situations regarding rail defect management, an event tree (ET) analysis is performed. The ET is modeled to all events and actions with respect to inspection/repair intervention. The ET analysis evaluates the expected reliability of a rail after inspections and possible remedial actions. Based on these results, a life-cycle cost (LCC) model is formulated, taking into consideration the time value of money. To this end, applications of the model to optimization of inspection intervals and to investigation of the effect of nondestructive testing and remedial actions on the LCC and the interval are analyzed.
(cont.) As a result, it is possible to extend the present inspection interval. Additionally, the effect of detectability of nondestructive testing on the LCC is more significant than that of accuracy of nondestructive testing, and a proactive maintenance policy may reduce both the expected total cost and the number of inspections.
by Takashi Kashima.
S.M.
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Hyde, Paul. "Numerical techniques for optimising rail grinding." Thesis, University of Newcastle upon Tyne, 2012. http://hdl.handle.net/10443/1468.
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Grinding of rails is a technique widely used within the railway industry to balance the degradation of the condition of the rail with the required performance of the rail. The principal focus of this research is the impact of wear and rolling contact fatigue (RCF) cracks on structural integrity of rails, and how rail grinding affects this relationship. A numerical model which predicts growth of RCF-initiated cracks in rails has been adapted to take into account periodic grinding of the surface of the rail. The suitability of some of the simplifying assumptions of the adapted model, referred to as the Grinding Model, has been examined with a physical test program, using full scale rail vehicles and track. This test program studied the persistence of the characteristic surface roughness of the rail generated by grinding, and was carried out to determine whether the effect of this roughness on crack growth can be neglected in the Grinding Model. The Grinding Model has been used to predict crack size, in order to investigate the effect of different grinding strategies, consisting of a depth of grinding applied at a certain interval during a representative pattern of rail vehicle traffic over the rail. The use of the Grinding Model to find grinding strategies which match an optimum criterion has been demonstrated. The applicability of this optimisation technique and the model in its current state of development, to the specification of rail grinding operations, in the context of maximising safe rail life and minimising rail life cycle cost, is discussed.
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Holland, Chase Carlton. "Computational Methods for Estimating Rail Life." Thesis, Virginia Tech, 2012. http://hdl.handle.net/10919/41436.
Full textAbstract:
In American rail operations, rails fail due to the combined effects of rail wear due to repetitive wheel contact and the growth of surface and sub-surface cracks and flaws. Rail maintenance includes frequent uncoupled wear and ultrasonic inspections that determine the amount of wear that the rail has undergone and the presence of cracks and flaws. A rail is removed from service when its wear reaches a pre-determined wear limit or a flaw is detected in its cross section. In rail research, the life of a rail is typically estimated using fracture mechanic or fatigue methods and an assumed flaw geometry. Multiple models ranging from complex elastic-plastic finite element models to simplified representations of a beam on an elastic foundation have been developed to predict the life of a rail. The majority of rail failure models do not incorporate rail wear into their analysis, and assume an unworn rail geometry. In order to account for rail wear, certain models adopt simplified rail geometries that uncouple rail wear into top-wear and side-wear.
This thesis presents a rail failure model that describes the combined effects of rail wear and crack growth through the development of a functional relationship between input variables describing the geometry, loading, and material properties of a given rail and output variables describing the life characteristics of the rail. This relationship takes the form of multiple response surfaces estimating the desired output variables. Finite element models incorporating worn rail profiles and an assumed crack geometry corresponding to a detail fracture are combined to determine the state of stress and strain at the assumed flaw. Strain-life fatigue methods and fracture mechanic concepts are used to develop the output variables necessary to describe the life of the rail using the finite element model results. The goals of this research are to predict the remaining fatigue life and estimate the crack-growth rate of the rail based on the minimum number of geometry, loading, and material property independent variables. The outputs developed to describe the railâ s remaining life are intended to be used for the decision making for rail removal.Master of Science
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Qazizadeh, Alireza. "On Active Suspension in Rail Vehicles." Doctoral thesis, KTH, Spårfordon, 2017. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-208184.
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The topic of this PhD thesis is active suspension in rail vehicles whichis usually realized through sensors, controllers and actuation components.A well established example of an active suspension is the tiltingcontrol system used to tilt the carbody in curves to reduce centrifugalacceleration felt by passengers. Active suspension for rail vehicles is beingstudied since 1970s and in this PhD thesis it has been tried to expandon some aspects of this topic.This study extends the research field by both experimental and theoreticalstudies. In the first phase of the study which led to a licentiatedegree the focus was more on experimental work with active verticalsuspension (AVS). This was implemented by introducing actuators inthe secondary suspension of a Bombardier test train, Regina 250, in thevertical direction. The aim has been to improve vertical ride comfort bycontrolling bounce, pitch and roll motions.In the second phase after the licentiate, the studies have been moretheoretical and can be divided into two parts. The first part of the workhas been more focused on equipping two-axle rail vehicles with differentactive suspension solutions for improving the vehicle performanceregarding comfort and wheel-rail interaction. Three papers are writtenon active suspension for two-axle rail vehicles. Two of the papers discussthe use of H¥ control for wheelset guidance in curves to reducewheel-rail damage. The third paper shows that by use of active verticaland lateral suspension (AVS and ALS) in two-axle rail vehicles goodcomfort can be achieved as well. The paper then studies how the threeactive suspension systems (ALS, AVS, and ASW) interact once implementedtogether on a two-axle rail vehicle.The second part is a study on safety of active suspension systems.The study discusses a possible procedure to ensure that a designed activesuspension for a rail vehicle will be safe in all possible failure situations.QC 20170602