bluuebunny/crossref_metadata_2025 huggingface dataset:
Wayside Wheel/Rail Load Detector Based Rail Car Preventive Maintenance
Authors: McGuire B. , Sarunac R. , Wiley R. B.
Published: June 2009

To assess rail car operational performance and to identify poorly performing rail cars early, the Washington Metropolitan Area Transit Authority (WMATA) has acquired and installed a Wayside Wheel/Rail Load Detector (WRLD) and measuring system at one of its yards. The WRLD determines truck performance by measuring lateral loads, vertical loads, and angles of attack (and corresponding derived values such as lateral to vertical (L/V) ratios, speed, average car weight, and total train weight) as vehicles and trains pass the detector. The Association of American Railroads (AAR) introduced this technology in one of its research projects in the 1990s. However, this is the first successful attempt to implement WRLD technology for a transit application. A team of WMATA, Booz Allen Hamilton, and TTCI engineers is working to adapt this technology to be effective in the transit environment. Prior to installing the WRLD, the team performed a VAMPIRE® simulation to predict the range of key parameters that was anticipated at the measurement site and on a representative mainline curve. Real-time data collection and information processing allowed immediate access to the curving performance of individual rail cars. The data was used to assess vehicle dynamic behavior during acceptance testing. Data was stored in a database at the WRLD site, and could be accessed via an Internet link. This data was evaluated for generating performance alarms of poorly performing rail cars — an important project milestone, since gaining maintenance personnel’s confidence in the WRLD’s abilities was one of the major objectives. As an early warning device, the WRLD is a very effective tool to identify and select potential “troublemakers” for inspection and preventive maintenance. In addition, the system is also useful for evaluating selected vehicle series and overall fleet performance, by using median and mean single-wheel L/V ratios.
Optimization of Train-Speed Trajectory of Mass Rapid Transit Systems
Authors: Ke Bwo-Ren , Chen Nanming
Published: June 2009

This paper presents a method for optimizing train-speed trajectory between two neighboring stations of a mass rapid transit system. This research uses the MAX-MIN ant system of the ant colony optimization algorithms to minimize energy consumption based on the framework of a moving-block signaling system of the mass rapid transit system. The alignment gradient is considered for energy saving. Several constrains, for example acceleration/deceleration and jerk of the train, as well as the average train speed, are also addressed according to the requirements of practical systems. In conclusion, this method will be used to design an operational system.
Tests and Numerical Simulations on the Thermal Load of the Cylinder Head in Heavy-Duty Vehicle Diesel Engines
Authors: Wang Zhaowen , Huang Ronghua , Cheng Xiaobei , Huang Yiwei , Shen Jie , Zhong Yuwei , Qin Jun
Published: June 2009

The paper has explored the solutions to the thermal overload in the cylinder head of a heavy-duty vehicle 6-cylinder diesel engine and the thermal cracks in the valve-bridge of the engine. The experiments include measuring the temperature of the cylinder head bottom and testing the flow distribution of coolant through the upper nozzles of cylinder head bottom. The follow-up analysis was conducted on the causes of the excessive thermal load of the cylinder head bottom, the thermal cracks in the valve-bridge region, and the rationality of the structure of the water jacket for the cylinder head. The mechanism of the water jacket of cylinder head was further inquired. Then 3-D CFD numerical simulation of water jacket in the sixth cylinder, which is in the worst cooling condition, is performed. To enhance the flow form in water jacket and lower the cost of enhancement, we proposed 4 schemes of water jacket and conducted the numerical simulations to these schemes. It was identified that all these schemes have efficiently improved the flow field in water jacket. In the typical proposed scheme 1 in which 6 nozzles of all the 10 upper nozzles were blocked, the coolant flow rate on the bottom of the water jacket and in the cylinder head valve-bridge region increased by about 68.73%. The measuring results of the cylinder head bottom temperature show that the maximum temperature in the valve-bridge region of cylinder head is reduced by 9.2 °C and the temperature gradient reduction is 19.55 percent, suggesting that the thermal load and thermal stress of the studied diesel engine cylinder head has been significantly lowered.
Advanced Combustion System Solutions for Increasing Thermal Efficiency in Natural Gas Engines While Meeting Future Demand for Low NOx Emissions
Authors: Tozzi Luigi , Sotiropoulou Emmanuella , Hicks Paul
Published: June 2009

Key requirements for state of the art industrial gas engines are high engine thermal efficiency, high engine brake mean effective pressure (BMEP), low NOx emissions, and acceptable spark plug life. Fundamentally, as engine thermal efficiency and power density increase, along with the requirement of reduced NOx emissions, the pressure at the time of ignition increases. This results in a higher spark breakdown voltage that negatively affects spark plug life. This problem is resolved with a smaller electrode gap and high spark energy to overcome quenching effects during ignition kernel development. High flow fields in the spark gap region are required to assure the spreading of the discharge, which reduces the rate of electrode erosion. In addition, these high flow fields overcome mixture inhomogeneities by developing large ignition kernels. These large ignition kernels, inside the prechamber spark plug, produce high velocity flame jets into the main chamber enhancing combustion, which results in thermal efficiency gains at lower NOx levels and higher BMEP. The advanced combustion system solution discussed in this paper is the combination of high-energy ignition and a prechamber spark plug with flow fields at the electrode gap. Future developments include improved ion signal quality detonation detection resulting in additional gains in thermal efficiency.
Rail Vehicle End of Car Hose Flexibility Testing
Authors: Cobden Geoff , Stroman Natala , Ely Sean
Published: June 2009

This paper describes how rail vehicle end hoses, that form the connection between the brake equipment on adjacent vehicles, have been traditionally tested for flexibility and a new test method that was recently introduced in The Association of American Railroads Specification (AAR) M-601 [1]. The Railroads had expressed a need to be able to perform both initial hose assembly specification compliance and subsequent quality assurance performance tests under controlled temperature conditions. This led to the development of a new test device and a simplified test procedure, which closely simulates the actions of railroad personnel when connecting end hoses in the train yard. This paper describes how end hoses have traditionally been tested, the evolution of a new test device, and the steps taken to qualify it for acceptance by the AAR as the test method in the recently revised Specification M-601.
Cyclic Variations of Ignition Timing in an HCCI Engine
Authors: Shahbakhti Mahdi , Lupul Robert , Koch Charles Robert
Published: June 2009

Understanding the effect of modifying the properties of the engine charge on the cyclic variations of ignition timing is one essential aspect of being able to predict and control the ignition timing in Homogeneous Charge Compression Ignition (HCCI) engines. This paper investigates cyclic variability of HCCI ignition timing using the experimental data from two different engines at over 300 operating points for five different blends of iso-octane and n-heptane. Experimental results indicate that the cyclic variations of HCCI auto-ignition timing decrease with an increase in the intake manifold temperature and mixture richness, but it increases with an increase in the EGR rate.
A Machine Vision System for Automated Joint Bar Inspection From a Moving Rail Vehicle
Authors: Gibert-Serra Xavier , Berry Andrea , Diaz Christian , Jordan William , Nejikovsky Boris , Tajaddini Ali
Published: June 2009

Broken joint bars have been identified as one of the major causes of main line derailments in the US. On October 2006, the US Federal Railroad Administration issued a federal regulation that mandates periodic inspections to detect cracks and other indications of potential failures in CWR joints [1]. The rule requires periodic on-foot inspection or an approved alternative procedure providing equivalent or higher level of safety. This paper describes a new machine vision-based system for joint bars inspection at speeds up to 70 mph. Four line-scan cameras mounted on a hi-railer or full size rail vehicle continuously capture high resolution images from both sides of each rail. An on-board computer system analyzes these images in real time to detect the joint bars. Each joint bar image is automatically saved and analyzed for visible fatigue cracks. The images can also be analyzed for missing bolts and other defects. When a potential defect is detected, the system provides audio warning, tags the image with GPS position, and displays the joint bar image with highlighted defects on the screen. The operator may confirm or reject defects. At the end of the survey, the operator can generate a survey report with the joint bar GPS location and types of all defects. This new system improves productivity and workers safety, inspecting joint bars from a moving vehicle instead of having to walk along highly transited tracks. It also allows the railroads to reduce the time between inspections, preventing defects to develop into hazards. Several tests have been performed on different rail roads showing system defect detection capabilities on both CWR and jointed track.
Root Cause Analysis Increases Locomotive Reliability at Amtrak
Authors: Ruppert Daniel , Hull George , Green Bruce , Golden Robert , Binns George , Latino Mark
Published: June 2009

In 2006, Amtrak instituted a program that coupled Reliability Centered Maintenance (RCM) with Root Cause Analysis (RCA) to increase rolling stock reliability. The RCM-RCA program at Amtrak combined features of RCM and RCA into a unique methodology to achieve success. A case study of the High Horsepower electric locomotive (HHP-8) power module failure RCA project is described in this paper. The initial focus of the RCA was a persistently high failure rate of power modules. Power modules are expensive to purchase and labor intensive to replace. Additionally, power module failures take locomotives out of revenue service. Partially as a result of the HHP-8 Power Module RCA project, and the implemented recommendations, the availability of the HHP-8 locomotive fleet has improved by 80%. Changes were made to the maintenance, condition monitoring, and troubleshooting procedures for HHP-8 as a result of the RCA project. The physical, human, and latent root causes for the high failure rate of HHP-8 Power Modules, were determined and addressed during this six month effort. A cross-functional team of AMTRAK personnel worked closely with reliability consultants and the original equipment manufacturers to determine the various root causes. This case study is a valuable example of how the hands-on nature of a rigorous RCA coupled with the methodology of RCM can result in significant improvements to reliability and availability.
Exploring the Potential for the Application of Ceramic Bearing Technology to the Wheel/Rail Interface
Authors: Arnold Gerald E.
Published: June 2009

Ball or roller bearings have much in common with a railway wheel running on a rail. Both have high Hertzian stresses and are subject to rolling contact fatigue. Silicone Nitride (Si3N4), a Technical Ceramic, has now firmly established itself in the engineering marketplace as part of a hybrid bearing, where the rolling elements are silicone nitride and the races are steel. The paper explores the possibility of a Silicon Nitride/steel wheel/rail combination and finds that, because Silicon Nitride has a higher Modulus of Elasticity, it is not suitable as a direct replacement on existing systems, because it would produce a smaller contact patch and greater contact stress. The low toughness of Silicon Nitride in comparison to steel could be an obstacle to its general railway use, however, it could made into a composite material in the same manner as Carbon Reinforced Silicon Carbide (C/SiC) is used in brake discs. There is a possibility that, under the right conditions, Silicon Nitride could return very low wear rates, because of its extreme hardness, and because it’s excellent resistance to rolling contact fatigue (noted in hybrid bearings). This could give a wheel high mileage, without the need to remove fatigued material by controlled wear or by turning. A promising future application for the material is a cable-hauled system, where the predicted lower adhesion between Silicon Nitride and a steel rail is not a problem and the wheels are not required to be conductive.
Traction Power Substation Protection and Controls Using Programmable Logic Controllers
Authors: Pham Kinh D. , Luey Ja-Mie , Schroyer Darin
Published: June 2009

A number of microprocessor-based digital devices with communication capabilities have been manufactured for traction power substations. These devices include protective relays, fault recorders, and metering units. One such device is the SIEMENS SITRAS DPU96 relay that provides over-current and rate-of-rise protection for faults on DC traction power distribution system. To fully utilize this digital technology, Programmable Logic Controller (PLC) was the best mean of collecting and organizing data from these devices locally at the traction power substation and also provide easy interface with the SCADA system. PLC was also used for high rail-to-earth potential monitoring and protection. The trip characteristics of this relay require adjustability over the voltage ranges normally from 40Vdc to 160Vdc and time-delay range from 10ms to 3 seconds which can be easily accomplished with PLC programming. This paper describes the applications of digital relays, human machine interface (HMI), and PLC in a traction power substation.
Effect of Intake Port Bend Angle on Flow Field Inside the Cylinder of a DI Diesel Engine
Authors: Jayashankara B. , Ganesan V.
Published: June 2009

This paper presents the computational fluid dynamics (CFD) modeling to study the effect of intake port bend angle on the flow field inside the cylinder of a direct injection (DI) diesel engine under motoring conditions. The flow characteristics of the engine are investigated under transient conditions. A single cylinder DI diesel engine with two direct intake ports whose outlet is tangential to the wall of the cylinder and two exhaust ports has been taken up for the study. Effect of intake port bend angle (20°, 30°, and 40°) on the flow field inside the cylinder has been investigated at an engine speed of 1000 rpm. The pre-processor GAMBIT is used for model preparation and commercial computational fluid dynamics code STAR-CD has been used for solution of governing equations and post processing the results. CFD results during both intake and compression strokes have been compared with experimental results of Payri et-al [7, 8]. The predicted swirl ratio, radial velocity and turbulent intensity variations at different crank angles and at different locations are discussed. Distribution of velocity and turbulence intensity inside the cylinder is also discussed. It is observed that the intake ports with 20° bend angle produce maximum swirl and also results in a slight decrease in volumetric efficiency compared to intake ports with 30° and 40° bend angles and there is no appreciable variation in turbulent intensity. Hence, for the better performance of a DI diesel engine, it is concluded that the intake ports with 20° bend angle is most appropriate and CFD is an effective design tool to develop more efficient DI diesel engines.
A Multibody Dynamics Approach to Friction Wedge Modeling for Freight Train Suspensions
Authors: Steets J. , Chan B. J. , Sandu C.
Published: June 2009

This paper presents an effort to use multi-body dynamics with unilateral contact to model the friction wedge interaction with the bolster and the side frame. The new friction wedge model is a 3D, dynamic, stand-alone model of a bolster-friction wedge-side frame assembly. It allows the wedge four degrees of freedom: vertical displacement, longitudinal (between the bolster and the side frame) displacement, toe-in and toe-out, and yaw (rotation about the vertical axis). The dedicated train modeling software NUCARS® has been used to run simulations with similar inputs and to compare — when possible — the results with those obtained from the new stand-alone MATLAB friction wedge model. The stand-alone model shows improvement in capturing the transient dynamics of the wedge better. Also, it can predict not only normal forces going into the frame and bolster, but also use the associated moments to enhance model behavior. Significant simulation results are presented and the main differences between the current NUCARS® model and the new stand-alone MATLAB models are highlighted.
Crash Energy Management Crush Zone Designs: Features, Functions, and Forms
Authors: Priante Michelle , Martinez Eloy
Published: June 2009

On March 23, 2006, a full-scale test was conducted on a passenger train retrofitted with newly developed cab and coach car crush zone designs. This test was conducted as part of a larger testing program to establish the degree of enhanced performance of alternative design strategies for passenger rail crashworthiness. The alternative design strategy is referred to as Crash Energy Management (CEM) where the collision energy is absorbed in defined unoccupied locations throughout the train in a controlled progressive manner. By controlling the deformations at critical locations, the CEM train is able to protect against two very dangerous modes of deformation: override and large scale lateral buckling. The CEM train impacted a standing locomotive-led train of equal mass at 30.8 mph on tangent track. The interactions at the colliding interface and between coupled interfaces performed as designed. Crush was pushed back to subsequent crush zones, and the moving passenger train remained in-line and upright on the tracks with minimal vertical and lateral motions. This paper evaluates the functional performance of the crush zone components during the CEM test. The paper discusses three areas of the CEM consist: the leading cab car end, which interacts with a standing locomotive; the coupled interfaces, which connect the CEM non-cab end; and the trailing cab car end, which interacts with the attached trailing locomotive. The paper includes a description of the crush zone features and performance. The pushback coupler must absorb energy in a controlled progressive manner and prevent lateral buckling by allowing the ends of the cars to come together. The deformable anti-climbers are required to resolve non-longitudinal loads into planar loads through the integrated end frame while minimizing the potential for override. The energy absorbers must absorb energy in a controlled progressive manner. The engineer’s space must be preserved so that the engineer can ride out the event. The passenger space must be preserved so that the passengers can ride out the event. The prototype CEM design presented in this paper met all the functional design requirements. This paper describes how the crush zones perform at three different interfaces. Areas for potential improvements include the design of the primary energy absorbers, the placement of the engineer’s compartment, and the interaction between the last coach car and the trailing locomotive.
Magnetic Particle Inspection of Freight Car Axles and Wheel Sets
Authors: Schiavone Ben , Klein Richard M.
Published: June 2009

Magnetic particle inspection (MPI) is a nondestructive testing method used to test ferromagnetic components for surface and subsurface defects. The method, in use since the 1940’s is an efficient means of inspection. MPI as with all other inspection methods must be performed in accordance with specific steps to be effective. This paper provides an overview of the method and describes the test sequence to ensure proper inspection of components. The discussion will focus on inspection of freight car loose axles and wheel sets although the points brought forth apply to any part tested using MPI.
Flow and Atomization Models for C.R. Diesel Engine CFD Simulation
Authors: Cameretti Maria Cristina , Tuccillo Raffaele
Published: June 2009

In the present work, the authors investigate the spray evolution and, in particular, the atomization process in a diesel engine bowl by using the KIVA3-V computational code with different break-up models. After a preliminary test of the break-up models sensitivity to the grid size and topology, the same atomization models are employed for the two-phase flow calculation in the combustion chamber of a common rail, turbocharged diesel engine conceived for future HCCI applications. The computations are extended to the combustion process in order to proceed with an overall validation with experimental engine test data characterized by variable EGR rates. The liquid spray-air interaction is studied within a flow field generated by the previous gas exchange process, the external ducts being included in the computational domain. This allows a more realistic evaluation of the fuel-air mixing under the actual conditions occurring at different engine regimes.
Track Differential Settlement Model
Authors: Davis David D. , Chrismer Steven M.
Published: June 2009

A study of track settlement behavior at critical transitions such as road crossings and bridge approaches has yielded a model to predict the amount of differential track settlement at these transitions caused by ballast and subgrade deformation. This AAR ballast and subgrade deformation model has been developed from field and laboratory test data, and has been validated with field settlement measurements at bridge approaches where the ballast and subgrade properties were well documented. As an analytical tool the model can determine the rate of track differential settlement at transitions with traffic loading and to predict when tamping is required to correct track geometry. Also the model can determine the relative amount of deformation from the individual ballast and subgrade layers. These capabilities provide a means to assess whether the main source of deformation is the subgrade or the ballast and the best means to reduce differential settlement and decrease the frequency of tamping at these track transitions.
On-Board Detection of Derailed Wheel and Wheel Defects
Authors: Singh Som P. , Chitti Srinivas , Punwani S. K. , Stewart Monique F.
Published: June 2009

To improve railroad safety and efficiency, the Office of Research and Development of the Federal Railroad Administration (FRA) is running a project to develop and demonstrate an On-Board Monitoring Systems Concept (OBMSC) for freight trains. The project scope includes onboard detection of hot bearings, bearing defects, vehicle, ride quality, wheel tread defects, and derailed wheels. This paper presents an analytical model to detect derailed wheel conditions. In the model, an idealized wheelset with associated sprung and unsprung vehicle masses running on crossties is simulated using LS-Dyna software. Track structure (i.e., ties) ballast/subgrade, and soil are represented as linear elastic systems. This paper identifies wheelset vertical acceleration magnitude and associated frequencies for a derailed wheel for empty and loaded car conditions at various operating speeds. The research shows that the predicted wheelset acceleration magnitude for a derailed wheel overlap with those resulting from wheel tread defects, such as wheel flat, shells, and built-up tread. To differentiate between a derailed wheel and wheels with tread defects, a set of criteria is formulated based on amplitude and frequency ranges. Based on the analytical results from the derailed wheel model and field-tested results of revenue service wheels with tread defects, it is established that the OBMSC bearing adapter acceleration (BAA) can be used to detect a derailed wheel and conditions communicated to the train crew or other appropriate parties.
A Study on Adaptability of the Engine Control Module of an Existing Heavy Duty Diesel Engine to Optimize the Engine Performance With F-T Diesel Fuel
Authors: Kandulapati Praveen , Lin Chuen-Sen , Witmer Dennis , Johnson Thomas , Schmid Jack , Kenny Tristan
Published: June 2009

Synthetic fuels produced from non-petroleum based feedstocks can effectively replace the depleting petroleum based conventional fuels while significantly reducing the emissions. The zero sulfur content and the near zero percentage of aromatics in the synthetic fuels make them promising clean fuels to meet the upcoming emissions regulations. However due to their significantly different properties when compared to the conventional fuels; the existing engines must be tested extensively to study their performance with the new fuels. This paper reports a detailed in-cylinder pressure measurement based study made on adaptability of the engine control module (ECM) of a modern heavy duty diesel engine to optimize the engine performance with the F-T diesel fuel. During this study, the F-T and Conventional diesel fuels were tested at different loads and various injection timing changes made with respect to the manufacturer setting. Results from these tests showed that the ECM used significantly different injection timings for the two fuels in the process of optimizing the engine performance. For the same power output the ECM used a 2° advance in the injection timing with respect to the manufacturer setting at the full load and 1° retard at the no load condition. While the injection timings used by the ECM were same for both the fuels at the 50% load condition. However, a necessity for further changes in the control strategies used by the ECM were observed to get the expected advantages with the F-T fuels.
An Experimental and Numerical Study of a Miller Cycle for a Gas Engine Converted From a Diesel Engine
Authors: Choi Gyeung Ho , Kim Tae Kwon , Lee Boo Youn , Lee Ju Hee , Chung Yon Jong , Han Sung Bin
Published: June 2009

Studies on internal combustion engines have made great efforts to develop engines with high efficiency for energy saving and emission gas reduction. The thermal efficiency of an internal combustion engine can be increased by expanding the pressure energy obtained through combustion to the maximum extent to convert the supplied thermal energy into work to the maximum extent. The cycle that can realize this goal is the Miller cycle. This Miller cycle converts the supplied thermal energy into mechanical energy to the maximum extent by making the expansion ratio greater than the compression ratio by changing the intake valve close timing. It is essential that study be performed for the development of the engine with high efficiency for energy saving in this era of rising oil prices. Therefore, this study realized a low compression and high expansion ratio engine by changing the intake valve close timing in order to investigate the characteristics of the Miller cycle. Furthermore, it confirmed that both the compression pressure and maximum combustion pressure increased through thermodynamic analysis. In addition, using the engine analysis program developed by the Ricardo Company known as WAVE, this study obtained the result that the output, torque and break thermal efficiency increased by 2 PS, 1.5kg and 2%, respectively at WOT (Wide Open Throttle) position and ABDC55° through simulation by changing the intake valve close timing.
Mixture Preparation Strategies for a Four Valve Centrally Injected Flat Piston DISI Engine
Authors: Gunasekaran E. James , Ganesan V.
Published: June 2009

This paper reports the Computational Fluid dynamic modelling to study the mixture preparation strategies for a 4 valve DISI engine under motoring condition. The suitability of air guided mixture preparation concept for a flat piston engine is investigated. Three different valve configurations viz., standard valve, forward tumble shroud valve and reverse tumble shroud valve are used to create different bulk air flow pattern viz., standard tumble, forward tumble and reverse tumble inside the engine cylinder. Two speed viz., 1000 and 2000 rpm with different fuel injection timings (90°, 180° and 270°) have been considered. The fuel injector is located near central axis of the cylinder and the spark plug is located between the intake valves on the fire deck of the engine. Gambit Pre-Processor is used to create the computational domain and the commercial CFD package STAR CD is used for simulation and post processing. The effect of air motion inside the cylinder on the turbulent kinetic energy and equivalence ratio prevailing near the spark gap are studied. Compared to standard valve configuration the forward tumble and reverse tumble valve configurations are able to produce higher tumble index for the speeds simulated. The mean turbulent kinetic energy prevailing inside the engine cylinder is sustained for the forward tumble and reverse tumble cases, well into the end of compression stroke which is attributed to the higher tumble for these cases, which may enhance burning rate. For the simulated cases of no shroud valve the equivalence ratio at the spark gap for higher speed (2000 rpm) is higher than the lower speed (1000 rpm) for the same injection timing. This may be attributed to higher turbulence at higher speed. The same trends is noticed for the forward tumble shroud valve and reverse tumble shroud valve configuration cases except for 180° injection timing where the higher speed case produces lesser strength of mixture at the spark plug gap. From the analysis of the simulated cases for different bulk flow inside the cylinder the forward tumble configuration with wide spacing arrangement of spark plug and injector, consistently produces a better mixture near the spark plug gap for all the injection timing for the two speeds simulated. Hence the forward tumble air motion with wide space concept may be a viable strategy for maintaining proper equivalence ratio at the spark plug at different loads and better combustion stability.
Visual Recognition System of Elastic Rail Clips for Mass Rapid Transit Systems
Authors: Hsieh Hsiang-Yu , Chen Nanming , Liao Ching-Lung
Published: June 2009

In recent years, the railway transportation system has become one of the main means of transportation. Therefore, driving safety is of great importance. However, because of the potential of multiple breaks of elastic rail clips in a fixed rail, accidents may occur when a train passes through the track. This paper presents the development of a computer visual recognition system which can detect the status of elastic rail clips. This visual recognition system can be used in mass rapid transit systems to reduce the substantial need of manpower for checking elastic rail clips at present. The visual recognition system under current development includes five components: preprocessing, identification of rail position, search of elastic rail clip regions, selection of the elastic rail clip, and recognition of the elastic rail clip. The preprocessing system transforms the colored images into grey-level images and eliminates noises. The identification of rail position system uses characteristics of the grey-level variation and confirms the rail position. The search system uses wavelet transformation to carry out the search of elastic rail clip regions. The selection system finds a suitable threshold, using techniques from morphological processing, object search and image processing. The recognition system processes characteristics and structures of elastic rail clips. Experimental testing shows the ability of the developed system to recognize both normal elastic rail clip images and broken elastic rail clip images. This result confirms the feasibility in developing such a visual recognition system.
New Transformer Sizing Criteria Based on Moving Average Techniques for Railway Systems
Authors: Jimenez-Octavio J. R. , Pilo E. , Egido I. , Carnicero A.
Published: June 2009

This paper introduces new criteria based on moving average of apparent power for sizing transformers in railway systems. Usually, transformers are designed to fulfill thermal criteria which are evaluated along several load cycles reported in the standards and literature. Nevertheless, real railway load cycles are quite variable and difficult to predict, therefore simulation techniques are necessary to estimate them. Detailed thermal studies require electric and thermal simulations for very particular operation, maintenance and climatic conditions. Hence these studies are focused on that special conditions and imply high computational costs too. To face this problem new sizing design criteria are proposed. These are based on the calculation of the moving average of the demand power, considering a time window which depends on the thermal time constant of the transformer. Finally, the results obtained with the proposed design criteria are discussed and compared with those obtained with the conventional hot-spot temperature based criterion.
Computer Simulation and Validation of Fire Hazards in Fuel Tanks
Authors: Carter James , Harrigan Timothy , Punwani S. K.
Published: June 2009

Flammable materials such as gasoline, ethanol, and diesel fuel are commonly transported in bulk via rail. In many cases, pockets of vapor can be generated inside the tank that can present a hazard if spilled during a collision or other catastrophic accident. Vapor conditions above the Lower Explosive Limit (LEL) if exposed to an external ignition source can result in an explosion or fire. Alternately, residual vapors within a tank present an explosion hazard if not properly vented or inerted prior to maintenance activities. This paper summarizes a generalized study of hazards associated with flammable liquids using computation fluid dynamics (CFD) to predict vapor conditions within a tank or following a spill. The analysis was verified in laboratory testing using scaled tank geometries. A demonstration case was developed using diesel fuel in a locomotive fuel tank. Typical road locomotives carry 3000–5000 gal of diesel fuel during normal operation. As the locomotive consumes fuel, large volumes are available for vapor generation within the tank. In a post-collision scenario, under ambient temperatures over the flash point of the fuel, the vapor that vents to the atmosphere presents a significant fire hazard. Further, flammable mists can be generated by the sprays that develop due to fuel leaks from a moving train. Studies of accident cases over a 10 year period indicated that a fire occurred in 80% of the accidents in which fuel was spilled. A CFD analysis was applied to the geometry associated with a locomotive fuel tank. The analysis models the two phase flow using the “volume of fluid” formalism in Fluent, and using a user defined diesel fuel evaporation algorithm. The tank and environmental parameters included fuel volume, fuel temperature, and air flow within the tank, and critical values of vapor content, temperature and velocity were plotted. The analysis predicted ignition of the external vapor cloud at temperatures relevant to a spill in a summer environment in the southwest, and propagation of the flame into the fuel tank. Laboratory testing confirmed the analysis: Once ignited, a flame propagated into the tank, causing an explosion and fire. The analysis methods developed can be applied to a variety of geometries and fluids, providing a basis for full scale testing. The overall intent of the analysis is to aid in the development of fire mitigation approaches for fuel and flammable material transport that would be practical for railroad use.
An Optimization Procedure to Determine the Topology of AC Railways Power Supply Networks
Authors: Pilo E. , Rouco L. , Ferna´ndez A.
Published: June 2009

This paper presents an optimization procedure to determine the topology of AC railways power supply networks: location and type of the substations, catenaries to be used, location of neutral zones and location of autotransformers in 2×25kV systems. In the proposed procedure, a mixed integer programming problem (MIP) is formulated in order to minimize the total construction cost associated to the power supply network while satisfying technical constraints to ensure proper behavior of power supply system. The performance of the proposed procedure is evaluated for a study case corresponding to a part of the new Madrid-Barcelona high-speed line and the obtained results are discussed.
Experimental Measurement and Finite Element Analysis of Screw Spike Fatigue Loads
Authors: Dick Matthew G. , McConnell David S. , Iwand Hans C.
Published: June 2009

Screw spikes, also known as coach screws, are an advanced alternative to common cut spikes for track fastening. Despite their ability to secure tie plates with a clamp load and utilization of high strength steels, they are still susceptible to bending fatigue failure from lateral wheel loads. A novel method of measuring these bending loads on screw spikes was developed and implemented to characterize the load environment of the screw spikes. Results indicated that measured peak bending loads under lateral wheel loads reached as high as 10,000 lbs for individual spikes, while others carried no load whatsoever. A finite element model was developed to determine the tensile stress fields created by the measured bending loads. A good correlation was found between the FEA model predicted point of highest stress and the location of fracture. Through the testing and analysis it was determined that lateral wheel loads are not distributed evenly among the four screw spikes of a single tie plate. Instead, it was found that one spike carried nearly no load while the spike opposite of it carried more load. Using the finite element analysis it was determined that the spike exposed to the higher loading was subjected to tensile stresses above its endurance limit, which would eventually lead to a bending fatigue failure.
Acoustic Detection of Distressed Freight Car Roller Bearings
Authors: Anderson Gerald B.
Published: June 2009

Trackside Acoustic Detection System (TADS®) development spearheaded implementation of an acoustic freight car roller bearing detector whose purpose is to prevent in-service bearing failures (burned off journals and hot bearing detector train stops). The means of accomplishing this goal is by providing the user with a warning of internal bearing defects or degradation with component involvement and severity information. The Transportation Technology Center, Inc. (TTCI) began the TADS® development process in 1994 with basic research into bearing defect acoustic emissions. Subsequently, TTCI conducted prototype testing on a North American railroad, constructed and installed of several international beta test systems, and finally has sold production systems in North America and internationally. There are currently about 40 TADS® sites in operation world-wide with 2.0 or more systems scheduled for installation in 2007. The original mission for TADS® in North America was an early warning of bearing degradation to allow for scheduled maintenance, but after initial evaluation, this mission enlarged to include notification of potentially high risk bearings. The high risk bearing is defined as one with fairly large areas of internal damage and at an increased risk of overheating or failing in service. The high risk bearing has a different acoustic signature, dissimilar to that of smaller defects. This paper will outline the change in mission for this detector and describe the development of an improved capability for detecting these high risk bearings.
Waukesha Engine’s New 2 and 3 MWE High Performance, Ultra-Lean Engines and Enginators™ for the Worldwide 50Hz and 60Hz Power Generation Markets
Authors: Honl Corey A. , Rudnitzki Ryan M.
Published: June 2009

The following paper describes the release of the 220GL engine and APG2000/3000 Enginator™ product lines from Waukesha Engine. The major elements of the release that will be covered include the installation and calibration of the ESM® control system, the development of new capabilities to control fuel injection and its associated features, the integration of Waukesha-introduced components on the 220GL, high-level product strategy and justification, and early stage performance figures from development testing.
Detecting Crew Alertness With Processed Speech
Authors: Shimp Samuel K. , Southward Steve C. , Ahmadian Mehdi
Published: June 2009

This paper proposes a solution for improving the safety of rail and other mass transportation systems through operator alertness monitoring. A non-invasive method of alertness monitoring through speech processing is presented. Speech analysis identifies measurable vocal tract changes due to fatigue and decreased speech rate due to decreased mental ability. Enabled by existing noise reduction technology, a system has been designed for measuring key speech features that are believed to correlate to alertness level. The features of interest are pitch, word intensity, pauses between words and phrases, and word rate. The purpose of this paper is to describe the overall alertness monitoring system design and then to show some experimental results for the core processing algorithm which extracts features from the speech. The feature extraction algorithm proposed here uses a new and simple technique to parse the continuous speech signal coming from the communication signal without using computationally demanding and error-prone word recognition techniques. Preliminary results on the core feature extraction algorithm indicate that words, phrases, and rates can be determined for relatively noise-free speech signals. Once the remainder of the overall alertness monitoring system is complete, it will be applied to real life recordings of train operators and will be subjected to clinical testing to determine alert and non-alert levels of the speech features of interest.
Development of Crash Energy Management for Light Rail Vehicles
Authors: Kirkpatrick Steven W. , MacNeill Robert A. , Gough Glenn , Hice Emil
Published: June 2009

Rail vehicle safety standards for the United States have historically placed emphasis on static structural strength requirements to ensure safety. The primary requirements to ensure crash safety of light rail vehicles were static load cases including car body buff loads, collision post loads, corner post loads, etc. More recent developments for light rail vehicles in the United States have included crash energy management design methodologies. This is consistent with the trend in other modes of transportation applying modern crashworthiness engineering. The challenges of incorporating crash energy management into light rail vehicles are the lack of crashworthiness standards for the light rail industry, the introduction of new design methodologies, and the concerns of compatibility of new and older equipment. This issue of compatibility in vehicle designs would often inhibit introduction of innovations and potential safety improvements within an existing light rail transit system. However, there are ongoing efforts to address each of these challenges. The American Society of Mechanical Engineers has a committee working on the development of a new safety standard for light rail vehicles. Light rail vehicle manufacturers are increasingly using modern crashworthiness design principles. In addition, modern crash analysis methodologies allow for the assessment of vehicle incompatibilities in the design process. In this paper, the developments of crash energy management strategies in the light rail industry are discussed. These include the ongoing standards development efforts and the application of crash energy management principles in recent light rail vehicle design efforts. Examples will be provided for the use of crash analyses in a vehicle design. The interaction of the crash and static analyses will be discussed and examples of both compatible and incompatible collision scenarios will be presented.
Development and Evaluation of Automated, Wireless Instrumentation for Geotechnical Monitoring
Authors: Garich Evan , Blackburn J. Tanner
Published: June 2009

This extended abstract describes the development of an expandable wireless sensor node to monitor potential landslide hazards in remote locations. The development and evaluation aspects are described in the following order: data transmission, power management, and field evaluation. Brief conclusions are presented, along with a discussion of future and ongoing research.
Preliminary Evaluation of the Bump at the End of the Railway Bridge
Authors: Nicks Jennifer E. , Briaud Jean-Louis
Published: June 2009

Bumps often develop at the interface between the bridge deck and the approach embankment of a railway bridge. The differential track movement at this transition zone creates higher impact loads, reduced bridge and embankment life, possible safety hazards, and higher maintenance costs. This study investigates the extent of the problem, typical maintenance expense, reasons behind the bump, and possible solutions. Based on a survey conducted to evaluate current practice, the bump problem affects about 50% of all railroad bridges and costs each railroad company an estimated $2,550,000 on maintenance. The typical slope for current bumps is equal to approximately 1:150. Using LS-DYNA, a 3-D, non-linear finite element program, a simple, rigid system was simulated to find the range of impact forces resulting from different bump slopes. A parametric study will be conducted in the future to examine the components involved and to optimize various solutions, such as approach slabs. The results from the entire study will help to minimize the bump at the end of the railway bridge.
Friction Reduction Due to Lubrication Oil Changes in a Lean-Burn 4-Stroke Natural Gas Engine: Experimental Results
Authors: Quillen Kris , Stanglmaier Rudolph H. , Wong Victor , Reinbold Ed , Donahue Rick , Tellier Kathleen , Carey Vincent M.
Published: June 2009

A project to reduce frictional losses from natural gas engines is currently being carried out by a collaborative team from Waukesha Engine Dresser, Massachusetts Institute of Technology (MIT), Colorado State University (CSU), and ExxonMobil. This project is part of the Advanced Reciprocating Engine System (ARES) program led by the US Department of Energy. Changes in lubrication oil have been identified as a way to potentially help meet the ARES goal of developing a natural gas engine with 50% brake thermal efficiency. Previous papers have discussed the computational tools used to evaluate piston-ring/cylinder friction and described the effects of changing various lubrication oil parameters on engine friction. These computational tools were used to predict the effects of changing lubrication oil of a Waukesha VGF 18-liter engine, and this paper presents the experimental results obtained on the engine test bed. Measured reductions in friction mean effective pressure (FMEP) were observed with lower viscosity lubrication oils. Test oil LEF-H (20W) resulted in a ∼ 1.9% improvement in mechanical efficiency (ηmech) and a ∼ 16.5% reduction in FMEP vs. a commercial reference 40W oil. This improvement is a significant step in reaching the ARES goals.