Rail Side Research Articles

Condition monitoring of urban rail transit by local energy harvesting

The goal of this study is to develop a vibration-based electromagnetic energy harvesting prototype that provides power to rail-side monitoring equipment and sensors by collecting wheel-rail vibration energy when the train travels. This technology helps power rail–side equipment in off-grid and remote areas. This article introduces the principle, modeling, and experimental test of the system, including (1) an electromagnetic energy harvesting prototype with DC-DC boost converter and lithium battery charge management function, (2) wireless sensor nodes integrated with accelerometer and temperature/humidity sensor, and (3) a vehicle-track interaction model that considers wheel out-of-roundness. Field test results, power consumption, Littlewood–Paley wavelet transform method, and feasibility analysis are reported. An application case of the technology is introduced: the sensor nodes of the wireless sensor network are powered by the electromagnetic energy harvester and lithium battery with DC-DC boost converter, thereby continuously monitoring the railway track state; based on the Littlewood–Paley wavelet analysis of measured railway track acceleration data, the abnormal signal caused by the wheel out-of-roundness can be detected.

Multivariate statistical assessment of ambient air pollution in two coalfields having different coal transportation strategy: A comparative study in Eastern India

Coal transport by railways has clear advantages over road transport for longer run but it is not too free from associated environmental impacts such as ambient air well as soil pollution in vicinity of coalfields and siding areas. Present study systemically investigated the ambient atmospheric pollution using comprehensive monitoring and analyses of the air pollutants, their statistical behaviors, and estimation of the role of transportation mode for the evacuation of coal in two different coalfield areas. The meteorological parameters such as temperature, humidity, wind speed, and wind direction were collected together with particulate matters, gaseous pollutants and trace metals. The potential contributors were analyzed using principal component analysis. The association between particulate matters of different sizes was also explored using linear regression analysis. The bipolar plot is used in this study to examine the role of wind speed and wind direction on dilution of the pollutant concentration. We also developed an aggregate Air Quality Index, commonly used to indicate the level of severity of air pollution to the public, based on the combined effects of considered pollutants was taken into account the Indian coal mine standards. Results revealed that Kaniha area, dominated by rail transport, is more polluted than Kulda area having road way as main mode for coal handling and transport. Thus railways pose specific challenges i.e. transportation of in-pit coal through road to railway siding and then loading and unloading at rail siding and requires further mitigation measures to make the railway transport as the appropriate choice for similar future projects like introduction of in-pit conveyor to silo loading system.

Application of grinding to reduce rail side wear in straight track

A stretch of straight rail on the Jing-Hu railway in China has been suffering from unacceptable levels of side wear. This phenomenon has not previously been investigated. This paper reports on work to analyse the causes using actual wheel and rail profiles from the track where it has occurred and a novel contact assessment approach and possible mitigations. By running a range of dynamic multibody simulations, it was shown that static calculations are adequate to represent the contact conditions that cause the wear. Almost 7000 wheel profiles were measured and their contact with the relevant rail profile calculated. It was predicted that freight trains whose wheels have a large rolling radius difference, would rub on the gauge corner and gauge face, thus causing the wear. This finding was consistent with field measurements.Two grinding strategies were developed that could reduce the number of damaging contacts. These were, grinding the gauge shoulder, and grinding the field side of the top of the rail. Calculations predicted that the largest improvement would result from combining both strategies. This approach was adopted to reduce the side wear on rail in straight track. It was found that the distribution of wheel/rail contact points on the rail surface agreed well with the calculation results, and the proposed grinding regime did reduce side wear.

The relationship between rail side wear and flange wear

Tokyo Metro owns many sharp curved metro lines. When vehicle passed that kind of curves, both wheels and rails are worn. The wear of wheels and rails increase a risk of the derailment. To solve this problem, oil application devices are installed on the curves. However, it couldn’t be a drastic solution. To conduct an efficient maintenance, it needs to grasp a tendency of the wear of wheels and rails. Therefore, in this research, the relationship between wheels and rails is inspected in terms of the degree of the wear. To grasp that relationship would be helpful when it comes to realize condition based maintenance.

A study on transient wear behavior of new freight wheel profiles due to two points contact in curve negotiation

Systematic examinations on wear behavior of stick/slip contact around metal on metal have shown that the dissipated energy and contact forces are two important parameters of wear of wheels and rails. Nevertheless, an accurate estimation of these parameters is still a great challenge. Recent developments of non-linear dynamical models and simulation of operational conditions have tried to find a solution of this challenge. These results are used as the input to calculations of wear propagation. Though, the dynamic model should be able to predict wheel-rail interaction with high accuracy. In addition, wheel-rail wear is a function of several other parameters whose their integrated influence becomes more than the main discussed ones. In this study, with the help of multi-body dynamics (MBD), an open wagon equipped with three pieces bogies, considering non-linear effects of friction wedges and structural clearances is modeled in Universal Mechanism. Tangent and curved sections of the track considering random vertical and lateral irregularities are simulated. The simulation results are used to calculate wear of both left and right wheels separately. Specht’s wear model based on Archard’s wear model is used. The studied parameters are the rail side coefficient of friction, track quality, track curvature, velocity and rail side wear. Finally, the effects of mentioned parameters are studied on wear depth and wear pattern of new wheel profiles under incompatible contact (which occurs in Iran railway network). The results show different wear volume and wear pattern compared to compatible contact.

Options for reducing noise from roads and railway lines

The fundamental noise generation mechanisms of road and rail vehicles are discussed with attention to noise abatement measures. Based on an evaluation of publicly available tire noise data and the European road traffic noise emission model CNOSSOS, it is shown that on the road side there is a significant noise reduction potential in the usage of low-noise tires. From a three months measurement campaign a noise model was derived to predict the maximal sound pressure level of heavy duty vehicles during a pass-by in 7.5m distance with the parameters vehicle speed and number of axles. With help of recently published information about external costs caused by heavy duty vehicles and the noise prediction tool, a model was developed to derive a money equivalent that can be used as a bonus/malus in a heavy duty vehicle fee. As a measure at the infrastructure, the installation of low-noise pavements is an effective, durable and economically attractive measure. Recent experiences with different technologies from all over the world are compiled and evaluated. On the rail side, an overview of the possible noise reduction strategies is given, followed by a discussion of the current policy and legislation in the EU and on the national level of different European countries.

Mechanism and affecting factors of Translohr tramway guide rail side wear

The wheel–rail contact can be found in two patterns. In the first pattern, the treads of both wheels are in contact with the two top surfaces of the ^-shaped guide rail; in the second pattern, the treads of both wheels are in contact with the two top surfaces of the ^-shaped guide rail, and the wheel edge is in contact with the guide rail web on one side. Based on these findings, an equivalent mechanical model with four unilateral springs is proposed to describe the wheel–rail contact. Additionally, a dynamic model of the Translohr tramway is established using Matlab/Simulink. The wheel–rail contact in a tramway moving along curves with different radii is calculated using simulation, and the results obtained are consistent with the observations and results of field measurements. The effects of various factors, including curve radius, tram speed, guide rail pre-pressure, and guide rod length, on the side wear of the guide rail were investigated. The results revealed that curve radius and tram speed are the critical factors affecting rail track side wear. These two factors can qualitatively determine rail track side wear, while other factors can only quantitatively affect the degree of rail track side wear.

A frictional contact finite element for wheel/rail dynamic simulations

The main purpose of this paper is to develop a simple-model moving wheel/rail contact element, so that the sticking, sliding, and separation modes of the wheel/rail contact can be appropriately simulated. In the proposed finite element, the wheel and rail are simulated using the cubic-spline contact element, and a power function normal stiffness and a constant horizontal stiffness are connected to the cubic-spline contact stiffness. The three-dimensional (3D) contact finite element analysis for a realistic wheel and rail was used to accurately model the wheel/rail contact stiffness. The validated examples show that the proposed nonlinear moving wheel element can simulate the complicated sliding, sticking, and separation contact problems with good accuracy. The complicated contact modes, including the multiple contact situation between wheel flange and rail side, can also be simulated accurately. Moreover, the computer memory and CPU time required to achieve this are much less than needed with the 3D finite element contact model.

鉄道車両の台車で測定した加速度によるレール波状摩耗の発生機構の推定

In this study, we examined the rail corrugation generated on the high rail of railway track, and measured acceleration of axle-box of the bogie of railway vehicle for clarification of the generation mechanism of rail corrugation. We tried to grasp the dynamic interaction between the vehicle and the track structure where the rail corrugation had been generated on the high rail by analyzing the data of the axle-box acceleration. As a result, we confirmed that the track supporting stiffness had a great influence on the generation of the high rail corrugation. Then, it is estimated that the high rail side wheel of leading axle of bogie resonated remarkably at about 60Hz with the track of which the sleeper was not elastically supported, and the high rail corrugation was caused by this vibration.

Operation of freight railways in densely used mixed traffic networks – An impact model to quantify changes in freight train characteristics

As freight transport is a growing challenge for metropolitan areas, there are calls to reintegrate rail freight into urban logistics. The use of railway systems in urban logistics should help to mitigate negative externalities such as noise, congestion and air pollution. Additional strengths of rail transport are the use of road-independent infrastructure, providing a reliable secondary mean of transport, and the high energy efficiency. A number of different concepts have been outlined – mostly conceptually, focussing on the intermodal interface, i.e. urban road-rail terminals or urban cross docks.This paper focuses on the rail side of urban logistics. It highlights the operational and technical challenges of operating freight trains in densely used railway networks with mixed traffic, against the background of railway network capacity consumption. The purpose of this study is to determine the effect of the characteristics of freight train on capacity consumption in mixed traffic railway networks. It devises an impact model to identify the drivers of capacity consumption and consequently to present effective ways to make better use of capacity in urban railway networks.To maximise the number of train paths in a mixed-traffic network, the technical and operational discrepancies between passenger and freight rail transport need to be reduced. Since passenger transport is the predominant user of railway networks in metropolitan areas, freight trains are required to adapt to the characteristics of passenger trains. A variation of the factors speed, acceleration, deceleration and train length has shown that the relative capacity consumption of freight trains can be reduced. The impacts of the factors considered however differ significantly.

The Calculation and Analysis for the Independent Wheels of Tramcar

The wheel/rail profiles in different wear stages are measured using the apparatus of wheel-rail profile. The 3D elastic-plastic FEM contact models are established for the straight line and curves, in which attack angle is considered. Contact problems between the wheels in different wear stages and the worn rail are studied. Contact area, normal contact force, and equivalent Von Mises stress of different cases are analyzed. The obtained results show that the maximum equivalent Von Mises stress reduces and tends to be steady with the independent wheel wearing. Widening the track gauge can have an influence on the variation of wheel wear positions and the wear rules between wheel and rail. When the wheel with a certain attack angle contacts with rail, the maximum equivalent Von Mises stress appears at the contact region between the flange and rail side. The influence of attack angle on the wear between the wheel and rail is quite serious. It is very important to do the research for the further optimization and design of the wheel/rail profiles.

Reducing rail side wear on heavy-haul railway curves based on wheel–rail dynamic interaction

This article investigates an optimisation strategy for the design of rail-grinding profiles to be used on heavy-haul railway curves, aiming to reduce the rail side wear on curves. A design methodology of rail asymmetric-grinding profiles is put forward based on the principle of low wheel–rail dynamic interaction. The implementing procedure is illustrated in detail. As a case study, the rail asymmetric-grinding profiles were designed for a curve with 600 m radius on Chinese Shuohuang heavy-haul railway. The characteristics of wheel–rail contact geometry and wheel–rail dynamic interaction were analysed and compared between the original standard rail profiles and the designed rail-grinding profiles. The rails on a test curve were ground according to the designed profiles. Before and after rail grinding, both the wheel–rail dynamics indexes and the rail side wear were measured in the field. The theoretical and experimental results show that the wheel–rail dynamic interaction is clearly improved and the rail side wear is alleviated by 30–40% after rail grinding, which validates the effectiveness of the design methodology of rail asymmetric-grinding profiles on curves.

Learning from the other side of the bed rails

Learning from the other side of the bed rails

Potentiality of Biodiesel Production From Non-Edible Oil: Bangladesh Perspective

The present study focuses potentiality of biodiesel production in Bangladesh from non-edible oil. The increasing demands of energy are consumed by using fossil fuels which are non-renewable and will be depleted within 150 years from now if this growth rate stays but if this rate increases further the depleting time will decrease from the estimated one. Because of low reservation of crude oil, Bangladesh has to import oils from other countries, these costs a lot. About 95% of these demands can be meted through biodiesel. Biodiesel prepared from both edible and non-edible oils. After meeting demands of edible oil of the country it is impossible to produce biodiesel from edible oils. But it is possible to meet the biodiesel demand of the country almost 100% through non-edible oil derived biodiesel. Arable lands of Bangladesh can’t be used for the growing purposes of non-edible oil seeds, but if rail and road sides are used there is no need for extra lands. After surveying lands for this purpose it seems that Bangladesh can get a total amount of 47750 Km of road and rail side areas for the cultivation of non-edible seeds. Among these forest seeds Nageswar, Pitraj, Sultana champa Ponyal, Rata, Oil palm, Chaulmoogra, Bakul, Kusum, jaina have sufficient oil content along with plenty of growth in Bangladesh. Cultivating these seeds 1100000 tones of biodiesel can be produced on the basis of their oil content and yield. Which decreases the amount of imported crude oil as well as meets the oil demand of the country, thus Bangladesh can be able to save about $6 billion per year means a great economic savings that can be used for the development of the country. DOI: http://dx.doi.org/10.3329/jce.v27i2.17763 Journal of Chemical Engineering, IEB Vol. ChE. 27, No. 2, June 2012: 1-5

Effect of laser quenching on wear and damage of heavy-haul wheel/rail materials

In order to alleviate the wear of heavy-haul wheel/rail materials, the wear experiments of wheel/rail rollers undergoing laser quenching were carried out using rolling-sliding testing apparatus. The results indicate that laser quenching produces a hard martensite layer with a certain depth. The improvement of wear resistance of materials resulting from laser quenching markedly decreases the wear volume of wheel/rail rollers. The maximal decrease rate of wear volume of wheel and rail materials is about 92.9% and 89.5%, respectively. Furthermore, the worn surfaces of wheel/rail rollers present different surface morphology and damage mechanisms due to difference of hardness matching. When the surface hardness of wheel/rail rollers undergoing laser quenching is high, the spalling damage and adhesion wear are dominating. When a single wheel or rail roller undergoes laser quenching, the damage mechanism of wheel and rail rollers are significantly different. According to the severe wear region of the heavy-haul wheel/rail, it is proposed that the rail side and wheel flange may undergo laser quenching treatment for alleviating wear of heavy-haul wheel/rail materials. However, further work should be carried out for clarifying the fatigue characteristic of wheel/rail with laser quenching.

Vibration and Acoustic Emission Measurements Evaluating the Separation of the Balls and Raceways With Lubricating Film in a Linear Bearing Under Grease Lubrication

This paper deals with vibration and acoustic emission (AE) measurements evaluating the separation of the balls and raceways with lubricating film in a linear-guideway–type recirculating ball bearing (linear bearing) under grease lubrication. In the experiments, three types of commercial grease, AS2, LG2, and PS2, were used. The vibratory acceleration, AE, temperature, and electric conductivity (contact voltage) in the test bearing were measured, while a carriage of the test bearing was driven at a certain linear velocity. Experimental results showed that the measured vibratory acceleration, AE, and contact voltage of the test bearing were affected by the linear velocity and the base oil viscosity of the grease. Next, the rail side film parameter ΛR and the carriage side film parameter ΛC were examined for the test bearing in operation, and it was shown that the ΛR value was lower than the ΛC value. In addition, a condition for the separation of all the balls and raceways with lubricating film was presented. Finally, it was shown that the measured root-mean-square (RMS) values of vibratory acceleration or AE can be used for evaluating the separation of all the balls and raceways with lubricating film in the test bearing.

Investigation on the damage mechanism and prevention of heavy-haul railway rail

The objective of this paper was to investigate wear and damage behavior of heavy-haul railway rail. Furthermore, the mechanism and preventive measures of heavy-haul rail damage were explored in detail. The results show that the rail side wear and surface spalling are dominating damage mechanism for Datong-Qinhuangdao heavy-haul railway. With the annual transport volume increasing, average wear volume and maximal wear volume of rail side each month reach 1.98mm and 4.16mm, respectively. Rail side wear has become the decisive factor of replacing of heavy-haul curved rail. The hardness of damage rail is higher than that of new rail due to severe work hardening and plastic streamline deformation. Fatigue cracks initiate from wear surface of damage rail and there are different propagation path on the crack growing process. The intergranular and transgranular growth are dominating propagation modes for the heavy-haul rail cracks. Furthermore, there is a competitive and restrictive coupling relationship between fatigue crack damage and rail wear. Large axle load and unreasonable matching of wheel/rail profiles would cause serious wear and spalling damage of heavy-haul wheel/rail. New wheel profile with good matching ability for CHN75 rail should be designed and optimized. The laser quenching can increase surface hardness and improve wear-resistance of wheel/rail materials. The surface damage of wheel/rail specimens with laser quenching is relatively slight. In a word, laser quenching can be used to treat rail side and wheel flange for prolonging wear life of heavy-haul wheel/rail in the field.

A SOMNN Model for Transport Risk Assessment of Hazardous Materials by Rail

Railway siding for transport of hazardous materials is an important way in transporting of hazardous materials in China and they often result in catastrophic consequences for environment and society with a great deal of economic loss. Risk assessment for railway siding is an effective way to ensure its operational safety. This paper focuses on the application of self-organizing neural network (SOMNN) to assess the risk of the railway siding operational system and classify its risk factors. In this work, the system analysis method based on the characteristics of railway siding for hazardous materials is first used to establish the transport risk assessment index system. A comprehensive risk assessment model of railway siding has been developed with the SOMNN theory to improve present methods available for risk assessment of rail siding’s safety. A field case study about 15 railway slides for transporting of oil in Jilin broach center of China National Petroleum Corporation is undertaken so that the effectiveness of the proposed approach could be verified. The result is in line with the actual situation and indicates that this method used is feasible and rational. This model provides a new method for transport risk assessment of hazardous materials by rail. The method is also proved more efficient for both risk assessment and safety management. The work specified in this paper can be as reference to the assessment work in China.

On the Other Side of the Rails

On the Other Side of the Rails

Road and Rail Side Vegetation Management Implications of Habitat Use by Moose Relative to Brush Cutting Season

Plants cut at different times produce resprouts that vary in their nutritional value relative to when they are cut. To determine how vegetation management in transportation (road and rail) corridors at different times of the year could influence browse quality in the years following cutting, and how this could potentially influence encounters between herbivores and vehicles, we undertook a 3-year study. In 2001, at a wildlife viewing area near Prince George, British Columbia, Canada, we established a control area and treatment areas where shrubs and trees that are used as food by moose (Alces alces) were cut at the beginning of June, July, August, September, and October. In the fall, moose were most often observed browsing the resprouts of plants cut in August (years 1 and 2 post-treatment) and September (year 3). Cumulative winter track counts were highest in the uncut control area in the years following cutting. Spring pellet counts revealed that most pellets were deposited in the uncut (years 1 and 2) and August-cut (year 3) areas during winter. With the exception of the first year after cutting, browse removal by moose was highest for plants cut later in the growing season. Overall, our findings suggest that following cutting, plants cut later in the year are selected more often by moose relative to those cut earlier. To reduce browse use of corridor vegetation in areas where concerns for moose-vehicle collisions exist, we recommend that vegetation maintenance activities be conducted in the early summer months of June and July.