2019 Joint Rail Conference最新文献

{"title":"How Staged Head-On Collisions Changed Public Perception of Railroads","authors":"L. Thurston","doi":"10.1115/JRC2019-1329","DOIUrl":"https://doi.org/10.1115/JRC2019-1329","url":null,"abstract":"With any new mode of transportation comes new fears for both the public and those involved in the industry. The advent of the transcontinental railroad was no different. When the transcontinental railroad was complete and trains became more commonplace for travel, the biggest fear became the worst case scenario: a head on collision between two trains. The idea of the head on collision remained the biggest fear of the public because it happened and was based on reality, but was rarely witnessed, which made the idea even more lofty. But with the standardization of time in the 1880’s, there were fewer crashes and collisions of railroads, but people were still afraid. Railroad companies began to brainstorm the best way to change public perception, and began to stage head on collisions open to public viewing for a small fee.\u0000 Naturally, the idea took off, and head on collisions between trains became the next source of entertainment. For $2, spectators could watch two locomotives crash into each other at speeds of 58 miles an hour in Crush Texas, or even cheaper in Ohio. But this was more than just entertainment. William Crush, the most famous locomotive smasher had actually worked on the railroad known as the Katy. When asked by the executives of the railroad to boost sales, head on collision was his solution. Despite multiple injuries suffered in the crowd from shrapnel and an exploded boiler, this showcase worked, and ridership of the Katy increased dramatically. Crush’s display was not the first, or last time this took place around the country, but it was the most deadly, which makes it the most memorable and begs the question “what role do these staged collisions play in railroad history?”\u0000 Ridership in the decades leading up to these staged collisions was steadily declining, and safety measures were not taken into consideration. But with these staged collisions that turned around. People, not just the public were able to see and study the different collisions and put minds at ease. But it also tells about the United States population at the time. These staged collisions could not have happened in any other era because of the industrial revolution which allowed railroad companies to begin to replace old locomotives and iron tracks with steel.","PeriodicalId":287025,"journal":{"name":"2019 Joint Rail Conference","volume":"24 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2019-07-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"128231661","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Evaluation of the Remaining Prestress Force and Center Negative Bending Moment in Crossties Removed From Track After 25 Years of Service","authors":"James D. Scott, R. Peterman, A. Robertson, B. T. Beck, K. Riding","doi":"10.1115/JRC2019-1275","DOIUrl":"https://doi.org/10.1115/JRC2019-1275","url":null,"abstract":"Extensive research is currently being conducted by the team to understand the prestressing steel and concrete properties that cause high bonding stresses and lead to longitudinal splitting cracks, and how to mitigate this failure in future designs. One parameter of interest that affects the bonding stress is the amount of prestressing force in a crosstie. To help quantify the amount of prestress force necessary to provide a durable long-term crosstie, a study on existing crossties that have performed well in track for over 25 years was conducted to evaluate the center negative bending moment, and determine the remaining prestress force for each tie.\u0000 The remaining prestress force in each tie was determined using a new proposed method in which ties are loaded in direct tension. The new test method was also conducted on new ties instrumented with vibrating wire strain gages to verify the method. The testing results reveal that a majority of the existing ties evaluated have a remaining prestress force in the range of 84–95 kips. These forces are significantly lower than the remaining prestress force after losses of newer tie designs. This can be seen when comparing the tension test results of the existing ties with the results of the new ties.\u0000 Ties were loaded upside-down in four-point bending to determine their center negative cracking moments. The test setup and procedure used closely resembles the center negative bending moment test outlined in AREMA 30, with minor variations. For each different tie design in the study, the center negative design moment was calculated following the AREMA 30 procedure, and compared to the experimental cracking moments. Of the seven different existing tie designs investigated, four would meet the requirements of the current AREMA 30 center negative bending test.","PeriodicalId":287025,"journal":{"name":"2019 Joint Rail Conference","volume":"27 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2019-07-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"123432662","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Discovering Crash Severity Factors of Grade Crossing With a Machine Learning Approach","authors":"Dahye Lee, J. Warner, C. Morgan","doi":"10.1115/JRC2019-1231","DOIUrl":"https://doi.org/10.1115/JRC2019-1231","url":null,"abstract":"According to the Federal Railroad Administration (FRA) Highway-Rail Grade Crossing Accident/Incident database, more than 12,000 accidents occurred between 2012 and 2017 in the United States with casualties of around 3900. Despite repeated efforts to fully understand the risk factors that contribute to highway-rail grade crossing collisions, there still remain many uncertainties. A machine learning approach is proposed in this paper to find out significant factors, along with their individual impacts of crash severities at grade crossings. One of the most efficient and accurate machine learning algorithms, extreme gradient boosting (XGB or XGBoost), is applied to analyze 21 different accident and crossing -related characteristics per driver severities. The XGB model has been proven in previous studies across many research areas in transportation to outperform other machine learning-based methods and statistical classification methods, such as multinomial logit model, multiple additive regression trees, decision tree, and random forest, especially in prediction accuracy. Thereby, applying the algorithm is expected to provide highly reliable results to identify important factors that have impacts on injury severities at grade crossings. Such application will further aid the discovery of potential crossings with significant factors. The FRA’s Highway-Rail Grade Crossing Accident/Incident database from 2012 to 2017 is fused with the FRA Highway-Rail Crossing Inventory database for the analysis. Observations with missing information were removed from the original database. Crossing position under or over the railroad and pedestrian or other types of highway users were also not considered since they were not specifically of interest in this study. After the database cleaning process, it condensed to the total of 1,250 accidents out of the retrieved 12,630 from the combined database. The results show that adjacent highway traffic volume and train speed are the most significant factors causing accidents and injury severity. They are followed by the driver’s age and the estimated vehicle speed. It also indicated that truck-involved accidents and crossings with gates, flashing lights, and other types of warning devices combined, and highway user’s gender as a male also pertain to the higher injury rate. Through this study, it is possible to provide guidance to decision-makers in recognizing possible risks at-grade crossings that may cause driver casualties.","PeriodicalId":287025,"journal":{"name":"2019 Joint Rail Conference","volume":"4 1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2019-07-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"132006705","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Improve Safety at Highway Crossings Through Predictive Behavior and Innovative Technologies","authors":"John Hofbauer","doi":"10.1115/JRC2019-1317","DOIUrl":"https://doi.org/10.1115/JRC2019-1317","url":null,"abstract":"The science and technology used in highway crossings in the United States and around the world have come a long way from a single flagman sitting in a booth, equipped with a red flag or lantern in his hand, to clear tracks and stop pedestrians, horses, and or a motor coaches for an approaching train to a fully automatic warning system requiring limited monthly testing. Today’s highway crossings are monitored by railways and municipalities such that, any changes in railway or roadway traffic conditions can be scrutinized. These changes, an increase in train or vehicle traffic, may trigger the need for additional protection devices to be implemented to make highway crossings safer for all; passing trains, motorists and pedestrians. But, are these requirements enough to eliminate accidents.\u0000 Historically speaking, these accidents range from; failures with the activation of the warning system; distracted motorists or motorists not willing to comply to the warning; pedestrians rushing to beat the train while underestimating the trains speed or; fully knowing and willing to not stop at the flashing lights and gates and willing to take the risk and go around flashing gates. This paper will investigate the current and future technologies that are being tested and implemented on highway crossings as well as look into the predictive behavior of motorists and pedestrians as they approach crossings and how changes can be implemented to maximize the effectiveness of a highway crossing. Key elements from various studies will be included that have been suggested through analyzing driver’s behavior at highway crossings, as well as the additional technologies that have and can be implemented to provide additional warnings to alert motorist of trains approaching.","PeriodicalId":287025,"journal":{"name":"2019 Joint Rail Conference","volume":"129 1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2019-07-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"123447460","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Clustering Algorithms for Direct Current Track Coded Signals","authors":"Song Qin, N. Mijatovic, J. Fries, J. Kiss","doi":"10.1115/JRC2019-1300","DOIUrl":"https://doi.org/10.1115/JRC2019-1300","url":null,"abstract":"Designed for detecting train presence on tracks, track circuits must maintain a level of high availability for railway signaling systems. Due to the fail-safe nature of these critical devices, any failures will result in a declaration of occupancy in a section of track which restricts train movements. It is possible to automatically diagnose and, in some cases, predict the failures of track circuits by performing analytics on the track signals. In order to perform these analytics, we need to study the coded signals transmitted to and received from the track. However, these signals consist of heterogeneous pulses that are noisy for data analysis. Thus, we need techniques which will automatically group homogeneous pulses into similar groups. In this paper, we present data cleansing techniques which will cluster pulses based on digital analysis and machine learning. We report the results of our evaluation of clustering algorithms that improve the quality of analytic data. The data were captured under revenue service conditions operated by Alstom. For clustering algorithm, we used the k-means algorithm to cluster heterogeneous pulses. By tailoring the parameters for this algorithm, we can control the pulses of the cluster, allowing for further analysis of the track circuit signals in order to gain insight regarding its performance.","PeriodicalId":287025,"journal":{"name":"2019 Joint Rail Conference","volume":"175 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2019-07-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"114453970","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Evaluating a Constant-Current Load Model Through Comparative Transient Stability Case-Studies of a Synchronous-Synchronous Rotary Frequency Converter-Fed Railway","authors":"Lars Abrahamsson, J. Laury, M. Bollen","doi":"10.1115/JRC2019-1249","DOIUrl":"https://doi.org/10.1115/JRC2019-1249","url":null,"abstract":"This paper continues the pursuit of getting a deeper understanding regarding the transient stability of low-frequency AC railway power systems operated at 16 2/3 Hz synchronously to the public grid. The focus is set on the impact of different load models. A simple constant-current load model is proposed and compared to a previously proposed and studied load model in which the train’s active power is regulated.\u0000 The study and comparison is made on exactly the same cases as and grid as with the already proposed and more advanced load model. The railway grid is equipped with a low-frequency AC high-voltage transmission line which is subjected to a fault. The study is limited to railways being fed by different distributions of RFC (Rotary Frequency Converter) types. Both AT (auto transformer) and BT (booster transformer) catenaries are considered.\u0000 The RFC dynamic models are essentially Anderson-Fouad models of two synchronous machines coupled mechanically by their rotors being connected to the same shaft.\u0000 The differences in load behaviour between the proposed constant-current load model and the previously proposed and studied voltage-dependent active power load model are analyzed and described in the paper.","PeriodicalId":287025,"journal":{"name":"2019 Joint Rail Conference","volume":"284 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2019-07-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"116230093","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Stochastic Analysis of Transit Wheel Wear and Optimized Forecasting of Wheel Maintenance Requirements","authors":"J. Palese, A. Zarembski, K. Ebersole","doi":"10.1115/JRC2019-1305","DOIUrl":"https://doi.org/10.1115/JRC2019-1305","url":null,"abstract":"As transit vehicle wheels accrue mileage, they experience flange and tread wear based on the contact between the railhead and wheel-running surface. When wheels wear excessively, the likelihood of accidents and derailments increases. Thus, regular maintenance is performed on the wheels, until they require replacement. One common maintenance practice is truing; using a specially designed cutting machine to bring a wheel back to an acceptable profile. This process removes metal from the wheel and is often based on wheel flange thickness standards (and sometimes wheel flange angle). Wheel replacement is usually driven by rim thickness, which is continually reduced by wear and metal removed by truing.\u0000 This research study used wheel wear data provided by the New York City Transit Authority (NYCTA) to analyze wheel wear trends and forecast wheel maintenance (truing based on flange thickness) and wheel life (replacement based on rim thickness). Using automatic wheel-scanning technology, NYCTA was able to collect wheel profile measurements for nearly 4,000 wheels in its fleet over a six-month period, measured weekly. The resulting wheel measurement data was analyzed using advanced stochastic techniques to determine relationships for the changes in flange thickness over time for each wheel in the fleet.\u0000 Flange thickness wear rate relationships for each wheel were then used to forecast the time it would take for a wheel to reach the flange thickness maintenance threshold as defined by NYCTA standards. Furthermore, a subpopulation of wheels that exhibited very high rates of wear were classified as “bad actors” and identified for further investigation to understand the cause of accelerated wear. This allows for identification and addressing of causal factors that relate to accelerated wear, such as angle of attack and L/V ratio. NYCTA has recently started capturing such data that relates truck performance, which can be related to rate of wear.","PeriodicalId":287025,"journal":{"name":"2019 Joint Rail Conference","volume":"14 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2019-07-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"127930537","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"On Numerical Analyses of Rail Steel Fatigue Crack Growth Data","authors":"D. Jeong","doi":"10.1115/JRC2019-1264","DOIUrl":"https://doi.org/10.1115/JRC2019-1264","url":null,"abstract":"For a given material and set of test conditions, fatigue crack propagation behavior can be described by the relationship between cyclic crack-growth rate, da/dN and the fluctuation of stress intensity factor, △K. Such test data are usually displayed in a log-log plot. At intermediate values of △K, fatigue crack-growth data fall along a straight line such that a power-law equation may be used as a curve-fit to the data. Various numerical techniques are applied in order to (1) derive the crack-growth rate and (2) determine the parameters for the power-law equation.\u0000 Using data from laboratory tests conducted on rail steels, this paper explores the various numerical methods used to characterize fatigue crack-growth behavior. Tests were conducted using two different fracture-mechanics specimens (a standard compact tension specimen and a non-standard single edge notch specimen). Three different numerical techniques were applied to determine the fatigue crack-growth rate, da/dN from test data measuring crack length, a versus number of fatigue cycles, N: (1) secant method, (2) modified secant method, and (3) incremental polynomial method. Four different least squares regression analyses were then applied to determine the parameters for the power law. Moreover, the outcome of these analyses is to determine the combination of numerical techniques which yields the least amount of error when the crack-growth rate equation is integrated and compared to the original a versus N data. Fatigue life calculations performed by integrating the crack-growth rate equation demonstrate the sensitivity of predicted growth rates to the power-law parameters derived from the different regression analyses.\u0000 This paper explores the various numerical methods and techniques employed to analyze fatigue crack growth data using test data on rail steels.","PeriodicalId":287025,"journal":{"name":"2019 Joint Rail Conference","volume":"2 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2019-07-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"129166120","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"The Creation of Cab Signaling","authors":"John Hofbauer","doi":"10.1115/JRC2019-1314","DOIUrl":"https://doi.org/10.1115/JRC2019-1314","url":null,"abstract":"Cab signaling enforces the separation between trains as well as enforcing trains to reduce speed as the train approaches signals displaying STOP. Cab signaling allow for and provides a safe way to eliminate the number of wayside automatic signals while the number of controlled speeds can be increased. Light Rail Transit (LRT) systems today are built completely with cab signaling and only fixed wayside signals are placed at interlockings for routing information. Experimental cab signaling systems began in the United States in the 1920s, kicked off by the Interstate Commerce Commission (ICC) ruling that required some form of Automatic Train Control (ATC) be installed on one passenger division by 1925.\u0000 This paper will begin with examining the initial ATC designs (intermediate and continuous), the first experimental installations, the testing challenges and the overall enhancements that pioneered cab signaling systems in the US. The focus will include the teaming of the Pennsylvania Railroad with Union Switch and Signal (US&S) to develop, build and successfully test the continuous cab signaling system which later became the de facto standard. The early systems implemented used two (2) speeds, methods on adding a third speed and how the system became integrated with the existing automatic block signaling. How Pennsylvania Railroad (currently Amtrak) is still using the technology that started 100 years ago on the North East Corridor. It will also introduce how Light Rail systems operate on speed commands using cab codes.","PeriodicalId":287025,"journal":{"name":"2019 Joint Rail Conference","volume":"5 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2019-07-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"122760683","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Finite Element Analysis of Spike Failure in Elastic Fastening Systems for Wood Ties","authors":"Hailing Yu, Shushu Liu","doi":"10.1115/JRC2019-1235","DOIUrl":"https://doi.org/10.1115/JRC2019-1235","url":null,"abstract":"Finite element analyses (FEA) were conducted in this paper to understand the underlying mechanisms contributing to a commonly observed failure mode of cut spikes used with the elastic fastening systems for wood ties. This failure mode features fatigue cracking development in the internal cross-sectional spike surfaces located approximately 1.5 inches below the top surface of a tie. Previous computational studies applied elastic material properties with “perfect” material behaviors. The study presented in this paper adopted post-elastic failure models for both the steel spike and wood tie materials, which proved key to reconstructing the observed failure mode in modeling.\u0000 The commercial FE software Abaqus was employed in this study. Continuum FE models were developed for a single cut spike embedded in a wood tie. The steel spike was modeled to yield plastically upon reaching a yield strength limit. A user material subroutine documented by Abaqus was adopted to simulate the 3D orthotropic failure of the wood tie. Both the elastic properties and strength limits of the wood material were orthotropic, with the properties in the transverse direction significantly lower than those in the fiber direction. Different combinations of vertical, lateral and longitudinal forces were applied in the analyses, deforming the spike in various bending modes. The forces were increased in magnitude until the steel reached its yield strength (i.e., developed permanent plastic deformations), and the yielding locations were recorded and compared with the observed failure mode.\u0000 The FEA showed that damage initiated in the wood tie being pressed by the spike with sufficiently large forces and that wood damage preceded steel yielding. The farther the wood material deteriorated from the top down, the lower the steel yielding location was in the spike shaft. Longitudinal forces were reacted to in the weaker transverse direction of the wood tie and therefore resulted in lower damage initiation forces and lower steel yielding locations than lateral forces did. It was concluded that the orthotropic wood tie failure condition and a substantial presence of the longitudinal force were necessary conditions for the spike to initiate failure at about 1.5 inches below the top surface of a tie. This corroborated the findings in a derailment investigation involving the spike failure. The lateral force alone unlikely caused this failure mode, but the presence of a lateral force on the spike appeared to decrease the magnitude of the longitudinal force needed to initiate damage in the spike.","PeriodicalId":287025,"journal":{"name":"2019 Joint Rail Conference","volume":"58 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2019-07-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"129665134","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}