Acoustic Detection of Distressed Freight Car Roller Bearings

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.

Exhaust Emissions From a 2,850 kW EMD SD60M Locomotive Equipped With a Diesel Oxidation Catalyst

This paper describes the test results of a program to apply an experimental diesel oxidation catalyst (DOC) to a 2,850 kW freight locomotive. Locomotive emissions and fuel consumption measurements were performed on an Electro-Motive Diesel (EMD) model SD60M locomotive, owned by Union Pacific Railroad company, that had been recently rebuilt to EPA Tier 0 exhaust emission certification levels. Emission testing was performed at the Southwest Research Institute (SwRI) Locomotive Exhaust Emissions Test Center in San Antonio, Texas. US EPA-regulated emission levels of hydrocarbons (HC), carbon monoxide (CO), oxides of nitrogen (NOx), and participate (PM) were measured using U.S. EPA locomotive certification test procedures in three configurations; first a baseline with a relatively high sulfur diesel fuel (2,913 ppm sulfur) meeting EPA locomotive certification test specifications, and another baseline using ultra-low sulfur diesel fuel (ULDS), and finally a test using ULSD after the installation of a diesel oxidation catalyst designed and manufactured by MIRATECH Corporation (patent pending). The DOC was applied pre-turbine, within the exhaust manifold due to both space and exhaust temperature considerations. This paper describes the design of the DOC-equipped exhaust manifold, and reports the changes in the regulated exhaust emission levels between the baseline tests and after installation of the DOC. Also described is a locomotive on-board monitoring system used to monitor DOC performance during ongoing revenue service field testing.

Friction Reduction Due to Lubrication Oil Changes in a Lean-Burn 4-Stroke Natural Gas Engine: Experimental Results

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.

Crash Energy Management Crush Zone Designs: Features, Functions, and Forms

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.

Waukesha Engine’s New 2 and 3 MWE High Performance, Ultra-Lean Engines and Enginators™ for the Worldwide 50Hz and 60Hz Power Generation Markets

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.

Visual Recognition System of Elastic Rail Clips for Mass Rapid Transit Systems

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.

On-Board Detection of Derailed Wheel and Wheel Defects

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.

Exploring the Potential for the Application of Ceramic Bearing Technology to the Wheel/Rail Interface

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.

Advanced Combustion System Solutions for Increasing Thermal Efficiency in Natural Gas Engines While Meeting Future Demand for Low NOx Emissions

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 Car Crashworthiness Design and Testing: Lessons Learned

Following National Transportation Safety Board (NTSB) recommendations and directions from early 1996, the Washington Metropolitan Transit Authority (WMATA) has worked to provide the latest crashworthiness and passenger safety requirements for its new car procurements. Taking advantage of recent developments in the field of vehicle crashworthiness, new technical requirements were developed and implemented for the 5000 and 6000 series vehicles. To date, WMATA is the first transit authority in the U.S. to require a dynamic sled test per the APTA SS-C&S-016-SS Standard, and the second (after the New York City Transit Authority) to run full-scale vehicle crash tests. Previously, the strength-based philosophy was used to ensure some level of rail vehicle crashworthiness. However, WMATA is now implementing a strength-based crashworthiness approach, augmented with “energy-based” requirements. Should a collision occur, the Authority’s ultimate goal is to reduce passenger deceleration rates during a collision, while at the same time controlling the absorption of collision energy in a manner that minimizes loss of space in the occupied volume of the vehicle. The passenger survivability measure using maximum acceleration has been supplemented by introducing the duration of the acceleration as an additional criteria following the Head Injury Criteria (HIC) and Abbreviated Injury Scale (AIS) approaches developed for the automotive industry. WMATA’s crashworthiness requirements now include sustaining a hard coupling without any damage to the body or coupler (except emergency release), and head-on collision of two eight-car trains with specified passenger loads (one train stationary with brakes applied) with no permanent deformation of the passenger compartment and with the acceleration, level and duration not to exceed the specified HIC. The implementation of an “energy-based” crashworthiness approach was divided into several logical steps/stages. During the design process, several modifications were introduced to optimize crashworthiness and to ensure structural compatibility with the existing fleet. The design was verified by implementing full-scale testing, and potential passenger injuries were assessed by using instrumented anthropomorphic test devices (ATDs), and measuring the forces and accelerations acting on these ATDs during the test.