bluuebunny/crossref_metadata_2025_split huggingface dataset:
Smart Rail: Rail Integrity and Occupancy Monitoring Using Fiber Optic Technology
Authors: Smith Frank J. 
Published: July 2019

This paper provides an introduction to a Rail Break Detection and Train Location Detection using fiber optic technology called Smart Rail. The technology concept detailed in this paper not only detects the location of a broken rail, it also provides advanced warning of rail damage that may evolve into a dangerous condition. The same technology allows for the detection of trains and vehicles in the detection zone and provides location, speed and direction information.
The Smart Rail continuously monitors rails for changes in their ability support the train in a safe manner. Smart Rail technology is based on direct observations of the structural quality of the rail by means of rail strain detection. Smart Rail technology detects the location, speed and direction of vehicles on the rails without the need for onboard equipment. It reports the location of vehicles whether moving or not.
Smart Rail technology is also capable of detecting and providing a warning of: rail gauge separation, lose or missing track hardware, missing tie plates and flat wheels. Taken together this technology can assist in the prevention of derailments. The technology can be applied to existing rails with no need to modify any existing equipment or track circuits. The train detection range can be up to 50 miles per direction from one wayside location.
Finite Element Analysis of Spike Failure in Elastic Fastening Systems for Wood Ties
Authors: Yu Hailing , Liu Shushu 
Published: July 2019

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.
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.
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.
Cyber Security Analysis for Advanced Train Control System (ATCS) in CTC Systems: Concepts and Methods
Authors: Wang Zezhou , Liu Xiang , Wang Yongxin , Yavvari Chaitanya , Jablonski Matthew , Wijesekera Duminda , Sykes Brian , Holt Keith 
Published: July 2019

Advanced Train Control System (ATCS) is a proprietary network protocol that expands the functionality and efficiency of Centralized Traffic Control (CTC) systems, by using radio communications (radio code line) for message delivery. However, end-to-end cyber security issues were not considered during initial design of ATCS in the 1980s. Meanwhile, the landscape of cyber-physical threats and vulnerabilities has changed dramatically over the last three decades. Even though cutting-edge systems like Positive Train Control (PTC) have adopted security properties such as integrity check and encryption methods, major railroads in North America still deploy legacy ATCS standards to maintain their individual CTC system.
This paper first illustrated the background and general specifications of ATCS applications in North American railroads. The research team has noticed that few studies have systematically analyzed this topic since the emergence of ATCS, though its applications are still prevailing in the industry. Divided by both vital and non-vital operational scenarios, this paper presented case studies for ATCS-related vulnerabilities. We used a sender-receiver sequencing-based analysis and proposed a consequence-based simulation model to identify and further evaluate the cyber and physical risks under potential cyber-attacks. For the identified risk, the paper evaluated the likelihood based on the practical operational sequences, and recommended potential countermeasures for the industry to improve the security over the specific case. The research concluded that the fail-safe design in the ATCS systems would prevent the exploiting known security vulnerabilities which could result in unsafe train movements. However, the service disruptions under certain speculated attacks need further evaluation. At the end of this paper, we discussed our ongoing work for disruption evaluation in the wake of successful cyber attacks.
Use of Rail in Oil and Gas Regions of Texas to Reduce Truck Impacts
Authors: Warner Jeffery , Morgan Curtis , Rutter Allan , Lee Dahye 
Published: July 2019

Burgeoning oil and gas production in Texas with the application of hydraulic fracturing (fracking) and horizontal drilling techniques has dramatically impacted the condition of rural roadway infrastructure. Many rural roadways are now inundated with trucks traveling to and from oil and gas well areas. Recent estimates indicate that each horizontal well requires over 2,000 truckloads for construction, drilling operations, maintenance, and crude oil transport over the life of the well. Rail has been an active partner in oil and gas exploration by shuttling fracking sand and drilling supplies to the oil and gas regions and transporting crude and petroleum products from the regions not served by pipelines. This partnership is restricted by limited rail service points and infrastructure close to the active wells; however, expanding existing rail services and network infrastructure could move rail operations closer to the active production areas. The cost and safety impacts of extreme reduction in pavement life may be offset substantially with increased use of rail transport closer to drilling locations.
This paper examines the potential options regarding expanded use of rail transportation to address the growing costs of roadway rehabilitation in energy production areas in order to reduce roadway network impacts. Rail service expansion can be through better use of the existing freight rail network, increasing the number of and better placement of transloading facilities along the rail network, and/or through improved rail capacity from double tracking or extending new rail lines. Both the private and public sectors potentially could play a role. A number of privately developed transloading facilities have sprung up along existing rail lines, attempting to deliver fracking sand, pipe, and other supplies. Additionally, public economic development corporations have been actively pursuing development. Expansion of the railroad network could come through the use of special districts such as Rural Rail Transportation Districts (RRTDs), Regional Mobility Authorities (RMAs), or through reactivation of abandoned rail lines. These trends are also examined.
Locomotive Crash Energy Management Coupling Tests Evaluation and Vehicle-to-Vehicle Test Preparation
Authors: Llana Patricia , Jacobsen Karina , Stringfellow Richard 
Published: July 2019

Research to develop new technologies for increasing the safety of passengers and crew in rail equipment is being directed by the Federal Railroad Administration’s (FRA’s) Office of Research, Development, and Technology. Crash energy management (CEM) components which can be integrated into the end structure of a locomotive have been developed: a push-back coupler and a deformable anti-climber. These components are designed to inhibit override in the event of a collision. The results of vehicle-to-vehicle override, where the strong underframe of one vehicle, typically a locomotive, impacts the weaker superstructure of the other vehicle, can be devastating. These components are designed to improve crashworthiness for equipped locomotives in a wide range of potential collisions, including collisions with conventional locomotives, conventional cab cars, and freight equipment.
Concerns have been raised in discussions with industry that push-back couplers may trigger prematurely, and may require replacement due to unintentional activation as a result of loads experienced during service and coupling. Push-back couplers (PBCs) are designed with trigger loads meant to exceed the expected maximum service and coupling loads experienced by conventional couplers. Analytical models are typically used to determine these trigger loads. Two sets of coupling tests have been conducted that validate these models, one with a conventional locomotive equipped with conventional draft gear and coupler, and another with a conventional locomotive retrofit with a PBC. These tests allow a performance comparison of a conventional locomotive with a CEM-equipped locomotive during coupling, as well as confirmation that the PBC does not trigger at speeds below typical coupling speeds. In addition to the two sets of coupling tests, car-to-car compatibility tests of CEM-equipped locomotives, as well as a train-to-train test are also planned. This arrangement of tests allows for evaluation of the CEM-equipped locomotive performance, as well as comparison of measured with simulated locomotive performance in the car-to-car and train-to-train tests.
The conventional coupling tests and the CEM coupling tests have been conducted, the results of which compared favorably with their pre-test predictions. In the CEM coupling tests, the PBC triggered at a speed well above typical coupling speeds. This paper provides a comparison of the conventional coupling test results with the CEM coupling test results. The next test in the research program is a vehicle-to-vehicle impact test. This paper describes the test preparation, test requirements, and analysis predictions for the vehicle-to-vehicle test. The equipment to be tested, track conditions, test procedures, and measurements to be made are described. A model for predicting the behavior of the impacting vehicles and the CEM system has been developed, along with preliminary predictions for the vehicle-to-vehicle test.
A High Resolution Automated Prestressing Wire Indent Profiling System for Verification of Wire-Concrete Mix Compatibility
Authors: Beck B. Terry , Robertson Aaron A. , Peterman Robert J. , Savic Adrijana , Wu Chih-Hang John , Riding Kyle A. , Bloomfield John 
Published: July 2019

It is well-known that the geometrical characteristics of the indents on prestressing wire used in the manufacture of prestressed concrete railroad ties affect the magnitude of the transfer length. In particular, it has been shown that such parameters as indent depth, indent volume and indent sidewall angle all affect transfer length, with indent volume being a major influence. Previous research has shown that the larger the indent volume, the shorter the transfer length.
For full load bearing capacity, it is important that the transfer length not exceed the distance to the rail seat. Consequently, transfer length has been identified as a key diagnostic parameter for evaluating the load bearing capability of prestressed concrete railroad crossties. Furthermore, it has been proposed for use as a valuable quality control parameter.
Ongoing research, as well as previously published research results, also indicates that the geometry of the prestressing wire indents plays a major role in the formation of cracking. This is particularly important in the manufacture of concrete ties intended for high speed rail applications. Cracking and debonding of prestressing wires associated with ties in service can result in severe splitting and complete tie failure. It is therefore not sufficient to guarantee a safe transfer length alone, without consideration of the cracking propensity. The wire specifications in standard ASTM A881 are intended to promote quality prestressed railroad tie behavior; however, the detailed causes of cracking and splitting, and the specific indent features that are responsible, are not well-known from a quantitative perspective.
Until recently, inspection of prestressing wire indent properties consisted of sampling a few indents from a small segment of wire, providing very limited statistical information on wire indent properties. To address this deficiency, a high-resolution automated non-contact optical wire indent scanning system has been developed for completely and rapidly characterizing all relevant indent geometrical parameters. The system is capable of measuring large segments of wire to yield statistically significant samples of all relevant indent parameters including indent depth, indent width, indent sidewall angle, indent pitch, and indent volume. The current state-of-the-art in this system development, along with some new insights based on recent indent scanning results, will be presented. This system represents a valuable tool to aid in identifying the key indent geometrical features related to cracking. The overall goal is to quickly assess critical indent parameters, so as to ensure high-quality bond and eliminate in-track tie splitting failures.
Evaluating the Effect of Natural Third Body Layers on Friction Using the Virginia Tech Roller Rig
Authors: Radmehr Ahmad , Kothari Karan , Ahmadian Mehdi 
Published: July 2019

In this study, the effect of natural third body layers on the coefficient of friction and contact forces is evaluated using the Virginia Tech-Federal Railroad Administration (VT-FRA) roller rig facility. The test rig allows us to precisely control the contacting surfaces to study its effect on the wheel-rail interface forces and moments. Experiments have shown while running the tests, a slight amount of wear occurs at the running surfaces. The worn material deposits at the surface and behaves like a “natural” third-body layer at the contact, resulting in changes in traction coefficient and creep forces. The material wear and its accumulation on the running surfaces change with wheel longitudinal load and creepage.
A series of organized time-based experiments have been conducted with the running surfaces cleaned at the beginning of the test to study the effect of material wear accumulation on selected parameters including traction coefficient and creep forces over time. In order to highlight the effect of the natural third body layer on the wheel-rail contact forces, a series of experiments were conducted, in which the wheel and roller surfaces were cleaned in one case and left uncleaned in another. The results of the experiments are quite revealing. They indicate that when the running surfaces are cleaned after each test, the maximum creep force (or adhesion) is far lower than when the running surfaces are not cleaned, i.e., the natural third-body layer is allowed to accumulate at the surfaces. The results indicate that the wear debris act as a friction enhancer rather than a friction reducer.
The Creation of Cab Signaling
Authors: Hofbauer John 
Published: July 2019

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.
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.
Improve Safety at Highway Crossings Through Predictive Behavior and Innovative Technologies
Authors: Hofbauer John 
Published: July 2019

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.
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.
Waist circumference centiles for UK South Asian children
Authors: Shah Mahjabeen , Radia Dimple , McCarthy Huw David 
Published: July 2019

ObjectivesTo develop waist circumference (WC) centile curves for UK South Asian children, to make comparisons with published centiles for British, indigenous Indian and Pakistani children, as well as to make anthropometric comparisons with their UK white peers.DesignCross-sectional study.SettingSchool-aged children from London boroughs (main measures: 2004–2007).Participants1562 (652 boys, 910 girls) UK South Asian and 1120 (588 boys, 532 girls) UK white children aged 4.0–13.9 years.InterventionsWC, height, weight and body mass index (BMI).Main outcome measuresThe outcome measures were smoothed WC centile curves, constructed using the LMS (L = skewness, M = median, S = coefficient of variation) method. SD scores (SDS) were generated using UK90 and British (WC) growth references.ResultsWC increased with age for both sexes, rising more steeply at the upper centiles after the age of 6 years. Overall, UK South Asian children, similar to indigenous South Asian populations, had higher WC values than the British WC references. However, compared with their UK white peers, UK South Asian children had significantly (p<0.001) lower mean WC (UK white SDS=0.74 and SDS=0.64 vs UK South Asian SDS=0.32 and SDS=0.21 for boys and girls, respectively). Obesity prevalence was greater using WC than BMI for both ethnicities. At the 90th centile, for UK South Asian children, prevalence was 21.5% vs 24.4% for boys and 17% vs 24.5% for girls based on BMI and WC, respectively.ConclusionsThese curves represent the first WC centiles for UK South Asian children up to the age of 14 years. With a continued rise in childhood obesity, they provide a useful historical control for future comparisons.
Clinical relevance of endoscopically identified extrinsic compression of the oesophagus and stomach
Authors: Kumar Kishore , Patel Harish , Mehershahi Shehriyar , Tariq Hassan , Glandt Mariela , Erfani Mohamad , Dev Anil , Zhang Aiyi , Makker Jasbir 
Published: July 2019

BackgroundVarious degree of extrinsic compression of the oesophagus and stomach are experienced during upper endoscopy. However, its utility in clinical practice has not been studied.MethodsElectronic chart review of all upper gastrointestinal endoscopies done at our hospital between 2005 and 2016 was performed. A total of 79 patients with documented extrinsic compression on upper gastrointestinal procedure report who had a preceding or subsequent abdomen/chest CT imaging performed within 6 months were included.Results30 (38%) out of 79 patients had abnormal finding on CT scan. 14 (47%) out of 30 patients had an associated malignant lesion, whereas remaining had a benign lesion. Overall, patients with associated gastrointestinal symptoms (60% vs 22%, p=0.001) or history of weight loss (50% vs 16%, p=0.001) had increased odds of having an abnormal finding on CT scan compared with the patients who lacked such symptoms. Pancreatic cancer was the most commonly diagnosed malignancy. On subgroup analysis of patients with extrinsic compression and malignant lesion on imaging study, the likelihood of a malignancy was higher in blacks as compared with Hispanics (71%:29% vs 39%:61%, p=0.031), and with presence of gastrointestinal symptoms (64% vs 22%, p=0.003), presence of weight loss (64% vs 16%, p=0.0001) and hypoalbuminaemia (p=0.001).ConclusionFinding an extrinsic compression of the oesophagus and stomach on an upper endoscopy may suggest malignancy, and hence should prompt further work-up. Posterior wall gastric body compression may signal the presence of pancreatic cancer.