Quality and Safety Assurance of Railway Tracks by UAV

2015 ◽  
Author(s):  
Önder Halis Bettemir
Keyword(s):  
Railway Track ◽  
Economic Losses ◽  
Test Results ◽  
Imaging Geometry ◽  
Safety Assurance ◽  
Railway Tracks ◽  
Ground Control Points ◽  
Optical Images ◽  
Similar Imaging ◽  
Optic Image

Safety assurance of railway tracks is an important task because defects on the railway track may cause trains to be derailed. Unfortunately, there are many fatal train crashes reported in Turkey, Spain and India caused by derailment of the trains. Besides the fatalities, derailment of the trains causes significant economic losses, delay of the timetables and discomfort. Manually investigating the railway tracks are substantially time consuming and expensive. In addition to this, it is human dependent so that the task is prone to error, which may end up without noticing important defects. In this study, a robust and economical method, which automates the investigation of railway tracks, is proposed. The proposed method scans the railway track by a high-resolution optic camera mounted on an UAV. Obtained optic images of the railway track are georeferenced by automatically extracting the Ground Control Points (GCP). The railway track is extracted from the optic image by edge detection. Afterward, any defect on the railway track such as missing bolt or damage on the sleepers and any impropriety of ballasts can be detected by performing image analysis techniques. Advantages of the optic system are its lightweight, higher georeferencing accuracy, and low power consumption. Sony HX300 DSLR camera with 20.4 MP resolution is calibrated on the ground and optical images are obtained at similar imaging geometry. For this reason, flight altitude is fixed as 12 foot above the railway track. The optical camera is mounted on quadcopter, which has 6 kg of maximum take-off weight. The system is tested in Pittsburgh and satisfactory initial test results are obtained. Consequently, site tests showed that the proposed robust and economic system is a good candidate to be implemented for monitoring the railway tracks.

scholarly journals A Review of Different Aspects of Applying Asphalt and Bituminous Mixes under a Railway Track

Materials ◽  
2020 ◽  
Vol 14 (1) ◽  
pp. 169
Author(s):  
Kazem Jadidi ◽  
Morteza Esmaeili ◽  
Mehdi Kalantari ◽  
Mehdi Khalili ◽  
Moses Karakouzian
Keyword(s):  
High Speed ◽  
Review Paper ◽  
Railway Track ◽  
High Speed Train ◽  
Slab Track ◽  
Bituminous Mixtures ◽  
Railway Tracks ◽  
Potential Applications ◽  
Heavy Loads ◽  
Design And Construction

Asphalt is a common material that is used extensively for roadways. Furthermore, bituminous mixes have been used in railways, both as asphalt and as mortar. Different agencies and research institutes have investigated and suggested various applications. These studies indicate the benefits of bituminous material under railways, such as improving a substructure’s stiffness and bearing capacity; enhancing its dynamic characteristics and response, especially under high-speed train loads; waterproofing the subgrade; protecting the top layers against fine contamination. These potential applications can improve the overall track structure performance and lead to minimizing settlement under heavy loads. They can also guarantee an appropriate response under high-speed loads, especially in comparison to a rigid slab track. This review paper documents the literature related to the utilization of asphalt and bituminous mixes in railway tracks. This paper presents a critical review of the research in the application of asphalt and bituminous mixes in railway tracks. Additionally, this paper reviews the design and construction recommendations and procedures for asphalt and bituminous mixes in railway tracks as practiced in different countries. This paper also provides case studies of projects where asphalt and bituminous mixes have been utilized in railway tracks. It is anticipated that this review paper will facilitate (1) the exchange of ideas and innovations in the area of the design and construction of railway tracks and (2) the development of unified standards for the design and construction of railway tracks with asphalt and bituminous mixtures.

scholarly journals Analysis of Wheel Squeal and Flanging on Curved Railway Tracks

2019 ◽  
Vol 20 (12) ◽  
pp. 2077-2087 ◽  
Author(s):  
Jae Chul Kim ◽  
Yang Soo Yun ◽  
Hee-Min Noh
Keyword(s):  
Frequency Analysis ◽  
High Frequency ◽  
Railway Track ◽  
Railway Vehicle ◽  
Vertical Force ◽  
Railway Tracks ◽  
Noise Characteristics ◽  
Experimental Approaches ◽  
Curved Section ◽  
Natural Frequency Analysis

Abstract When a railway vehicle moves over a sharply curved section of track, intense high-frequency noises sometimes occur. These are potentially a source of annoyance to those living adjacent to railway tracks. To efficiently identify measures appropriate to reduce curve squeal, it is important to determine the dominant noise type. However, it is difficult to analyze the various noises made over curved sections of railway using general noise measurements. In this study, we analyzed squealing and flange noises using various experimental approaches. We first investigated the noise characteristics of the railway vehicle via structural analysis of the wheel. It was confirmed that a wheel has various natural frequencies and eigenmodes in the high frequency range, i.e. over 1000 Hz. A roller rig test was performed to measure and investigate the characteristics of the noise generated when an actual wheel and the curved section of the railway track come in contact with each other. In this experiment the squeal and the flange noises, in particular, were reproduced by adjustments made to the lateral angle and vertical force, respectively. Results confirmed that the squealing noise occurs in the high frequency region and the flange noise occurs in various modes. A study was also conducted to measure and analyze the noise in the actual curved section of an urban railway. By comparing the frequency analysis and the natural frequency analysis of the noise that was actually measured, the mode by which the wheel caused the squealing noise was confirmed. Furthermore, the influence of the noise generated inside and outside the curved section of the track was investigated based on velocity, and the influence of the former on the noise generated was also examined. This study provides information on the squeal and flange noises generated when a railway vehicle moves over a curved section of a railway using various experimental approaches.

scholarly journals Buckling Analysis of Interspersed Railway Tracks

2020 ◽  
Vol 10 (9) ◽  
pp. 3091 ◽  
Author(s):  
Chayut Ngamkhanong ◽  
Chuah Ming Wey ◽  
Sakdirat Kaewunruen
Keyword(s):  
Global Climate ◽  
Extreme Temperature ◽  
Railway Track ◽  
Significant Deterioration ◽  
Track Geometry ◽  
Railway Tracks ◽  
Life Cycle Design ◽  
Continuous Welded Rail ◽  
Natural Decay ◽  
Construction Strategies

Nowadays, timber sleepers are still used for ballasted railway tracks to carry passengers and transport goods. However, the process of natural decay causes the problem of timber sleeper degradation over time. A temporary “interspersed” approach is used to replace rotten timbers with concrete sleepers. This implementation has several inadequacies, as interspersed railway tracks have inconsistent stiffness and experience significant deterioration over the years. Increased heat due to the change in the global climate can induce a compression force in the continuous welded rail (CWR), leading to a change in track geometry called “track buckling”. A literature review shows that track buckling on plain tracks has been widely studied. However, the buckling of interspersed tracks has not been fully studied. This study presents 3D finite element modelling of interspersed railway tracks subjected to temperature change. The effect of the boundary conditions on the buckling shape is considered. The obtained results show that the interspersed approach may reduce the likelihood of track buckling. This study is the world’s first to investigate the buckling behaviour of interspersed railway tracks. The insight into interspersed railway tracks derived from this study will underpin the life cycle design, maintenance, and construction strategies related to the use of concrete sleepers as spot replacement sleepers in ageing railway track systems. The outcome of this study will help track engineers to improve the inspection of the lateral stiffness of interspersed tracks in areas prone to extreme temperature.

IMPORTANCE OF NONLINEARITY OF TRACK SUPPORT SYSTEM IN MODELING OF RAILWAY TRACK DYNAMICS

2013 ◽  
Vol 13 (01) ◽  
pp. 1350008 ◽  
Author(s):  
J. SADEGHI ◽  
M. FESHARAKI
Keyword(s):  
Support System ◽  
Field Tests ◽  
Field Investigation ◽  
Dynamic Responses ◽  
Railway Track ◽  
Nonlinear Properties ◽  
Railway Tracks ◽  
Track Dynamics ◽  
Track System ◽  
Axle Loads

Attention is drawn to the fact that the recent increase in axle loads, speed and traffic volume in railway tracks, as well as concerns over passengers' riding comfort and safety have resulted in fresh challenges that are needed to be addressed. These challenges can only be successfully tackled with a more accurate modeling of the dynamic behavior of railway tracks. Although a significant amount of research involving mathematical modeling of railway track dynamics has been conducted in the last two decades, the nonlinearity of track support systems has not been given sufficient attention. This paper is concerned with the effect of nonlinearity of the support sub-layers on the dynamic responses of the railway track. To this end, a railway track model that considers the nonlinear properties of the track sub-layers is developed. Then, a field investigation into the dynamic responses of the railway track system under moving trains is conducted. The effect of the nonlinearity properties of the track support system on the track responses is investigated by comparing the results obtained by the numerical model, with or without consideration of track support nonlinearity, with those from the field tests. It is illustrated that consideration of the nonlinear properties of the track support system improves the accuracy of the calculated responses by a factor of three. It is also shown that the train axle loads and track accumulative loading have a significant effect on the nonlinearity of the track support system and, as a result, on the modeling of track responses.

scholarly journals Prevention of Economic Losses with the help of the System of Control of Saving and Storing Bulk Cargoes in the Process of Train Movement

2019 ◽  
Vol 67 ◽  
pp. 02008
Author(s):  
Vitalyi Sakhatsky ◽  
Nina Lyubymova ◽  
Vladimir Pusik ◽  
Luydmila Pusik ◽  
Ievhenii Chepusenko
Keyword(s):  
Control System ◽  
Horizontal Plane ◽  
Rail Transport ◽  
Railway Track ◽  
Economic Losses ◽  
Radar Sensor ◽  
Safety Control ◽  
Transport Services

In order to ensure the demand of the market for competitive rail transport services, the structure of automatic safety control for bulk cargo is proposed on the basis of the radar sensor and Wi-Fi technology, which allows to avoid the false alert signal caused by changes in the level of liquid due to various deviations of the railway track from the horizontal plane and to fix leakage of the liquid from damaged tank. The issues of increasing the reliability of the proposed control system are considered.

scholarly journals Detection of ovine herpesvirus-2 in clinical cases of sheep-associated malignant catarrhal fever in balinese cattle and apparently healthy sheep in East Nusa Tenggara

2021 ◽  
Vol 33 ◽  
pp. 06006
Author(s):  
Agus Wiyono ◽  
Harimurti Nuradji ◽  
Maxs UE Sanam ◽  
Yohanes TRMR Simarmata ◽  
Rini Damayanti
Keyword(s):  
Fatal Outcome ◽  
Clinical Signs ◽  
Economic Losses ◽  
Malignant Catarrhal Fever ◽  
Test Results ◽  
Nested Polymerase Chain Reaction ◽  
Healthy Cattle ◽  
Healthy Sheep ◽  
Vaginal Swabs ◽  
Polymerase Chain

Malignant catarrhal fever (MCF) is a disease causing a fatal outcome in cattle and generates economic losses worldwide. This study aims to detect the cause of the disease in Balinese cattle showing clinical signs such as high fever, serous ocular mucopurulent nasal discharges, and enlargement of pre-scapularis and pre-femoralis lymphnodes. These cattle were previously housed 50 meters away from a flock of sheep which were brought from Sabu Island 3 months earlier. Samples including blood, ocular, nasal, and vaginal swabs were collected from 22 sheep, 30 goats, 33 clinically healthy cattle (22 Balinese and 11 Ongole cattle), and 3 infected Balinese cattle. Samples were processed and tested using A nested polymerase chain reaction (PCR) test. Results showed t hat 12 sheep out of 22 and 3 out of 3 infected Balinese cattle were positive MCF, suggesting a potential spread of the disease from sheep to Balinese cattle. No goats and Ongole cattle that were positive indicate that these animals are less susceptible to Ovine Herpesvirus-2 (OvHV-2) infection compared to Balinese cattle. The finding of 5 positive samples from 22 healthy Balinese cattle shows the potential of sub-clinical infection of OvHV-2.

scholarly journals An impact echo method to detect cavities between railway track slabs and soil foundation

2021 ◽  
Vol 68 (1) ◽  
Author(s):  
Pierre Anthyme Bahati ◽  
Viet Dinh Le ◽  
Yujin Lim
Keyword(s):  
Open Space ◽  
Concrete Slab ◽  
Test Methods ◽  
Railway Track ◽  
Element Analysis ◽  
Impact Echo ◽  
Time Frequency ◽  
Railway Tracks ◽  
Soil Foundation ◽  
The Impact

AbstractThe impact echo technique is one of the most useful non-destructive test methods for determining the thickness of concrete or detecting possible cracks or cavities in the internal parts of a concrete structure without damaging the surface. Many types of unstable conditions in railway tracks, including various modes of irregularities, may occur when cavities are generated directly under a concrete slab track or when a slight open space is made under a loose sleeper. In this study, we developed a nondestructive testing (NDT) system for detecting abnormalities in concrete tracks and performed 3D numerical simulations using the ABAQUS finite element analysis (FEA) program to investigate the impact echo response from a concrete track slab with different sizes of cavities. Sections of concrete slab were simulated as solid body masses under the railway tracks with gaps in the bodies themselves or with cavities existing between the track concrete layer (TCL) and the hydraulically stabilized base (HSB). We investigated the locations and depths of the cavities and gaps in the model concrete slab using the acoustic impact echo response based on the frequency response of the elastic waves generated in the slab. In addition, a Short-time Fourier Transform (STFT) and a wavelet technique were adopted for a time frequency analysis. Our study demonstrated that the impact echo technique developed in this study by FEA and NDT can measure and confirm the location and depth of cavities in concrete slabs.

scholarly journals Identification of Clostridium septicum in Clinical Cases Suspected to Braxy and Malignant Edema by Traditional and Molecular Method and Evaluation of Toxigenic Isolates for Vaccine Production

2020 ◽  
pp. 23-30
Author(s):  
Lida Abdolmohammadi Khiav ◽  
Alireza Paradise
Keyword(s):  
Pcr Amplification ◽  
Economic Losses ◽  
Toxin Gene ◽  
Test Results ◽  
Alpha Toxin ◽  
Vaccine Production ◽  
Molecular Method ◽  
Clostridium Septicum ◽  
Biochemical Tests ◽  
British Pharmacopoeia

Clostridium septicum is the causative agent of the acute fetal disease braxy and gas gangrene with major economic losses in the dairy industry. Accurate and rapid detection is great importance in this regard. Vaccination is an effective process for protection against C. septicum infection. It is necessary to identify and evaluate toxigenic Iranian isolates to produce a vaccine. This study aimed to detect Iranian isolates and evaluate toxigenic isolates as candidates for vaccine production. To this end, a total of 17 samples of animals, clinically suspected to braxy and malignant edema, were obtained. All samples were then cultured on media and microbiological and biochemical tests were performed on the colonies. The test results were confirmed by PCR amplification of the alpha-toxin gene. The toxigenic isolates were then evaluated using MLD. The experimental vaccine was produced and evaluated according to the British Pharmacopoeia Standard. According to the results, out of 17 samples, 15 samples were considered C. septicum. All samples were confirmed by PCR amplification. The most toxigenic isolate was used for experimental vaccine production. The result was successful. The Iranian isolate could be, therefore, used for vaccine production although further studies should be conducted in this regard.

scholarly journals Railway track design & degradation

2018 ◽  
Vol 211 ◽  
pp. 11006
Author(s):  
Mehran Sadri ◽  
Tao Lu ◽  
Arjen Zoeteman ◽  
Michaël Steenbergen
Keyword(s):  
Degradation Rate ◽  
Early Stage ◽  
Mechanical Energy ◽  
Measurement Data ◽  
Empirical Models ◽  
Railway Track ◽  
Structural Performance ◽  
Design Parameters ◽  
Railway Tracks

The long-term behaviour of railway track has attracted increasing attention in recent years. Improvements in long-term structural performance reduce demands for maintenance and increase the continuous availability of railway lines. The focus of this paper is on the prediction of the sensitivity of a track design to long-term deterioration in terms of track geometry. According to the state of the art literature, degradation is often investigated using empirical models based on field measurement data. Although a rough maintenance forecast may be made employing empirical models, the predictions are not generic, and the physical processes which govern track degradation under train operation remain unclear. The first aim of this study is to present a mathematical model to elucidate the underlying physics of long-term degradation of railway tracks. The model consists of an infinitely long beam which is periodically supported by equidistantly discrete sleepers and a moving unsprung mass which represents a travelling train. The mechanical energy dissipated in the substructure is proposed to serve as a measure of the track degradation rate. Secondly, parametric studies on energy dissipation are conducted to identify effects of various track design parameters on the susceptibility of the track to degradation, as well as the effect of the train speed. It has been shown that the track/subgrade stiffness is the most influential parameter on degradation whereas other system parameters do influence the degradation rate but at lower magnitudes. The conclusions can be used to optimise the track design in the early stage for better long-term structural performance of railway tracks.

scholarly journals Functional Analysis of preA in Aeromonas veronii TH0426 Reveals a Key Role in the Regulation of Virulence and Resistance to Oxidative Stress

2019 ◽  
Vol 21 (1) ◽  
pp. 98
Author(s):  
Bintong Yang ◽  
Haichao Song ◽  
Dingjie An ◽  
Dongxing Zhang ◽  
Sayed Haidar Abbas Raza ◽  
...  
Keyword(s):  
Oxidative Stress ◽  
Type Strain ◽  
Wild Type Strain ◽  
Lethal Dose ◽  
Tolerance Test ◽  
Economic Losses ◽  
Cytotoxicity Test ◽  
Test Results ◽  
Wild Type ◽  
Aeromonas Veronii

Aeromonas veronii is one of the main pathogens causing freshwater fish sepsis and ulcer syndrome. This bacterium has caused serious economic losses in the aquaculture industry worldwide, and it has become an important zoonotic and aquatic agent. However, little is known about the molecular mechanism of pathogenesis of A. veronii. In this study, we first constructed an unmarked mutant strain (ΔpreA) by generating an in-frame deletion of the preA gene, which encodes a periplasmic binding protein, to investigate its role in A. veronii TH0426. Our results showed that the motility and biofilm formation ability of ΔpreA were similar to those of the wild-type strain. However, the adhesion and invasion ability in epithelioma papulosum cyprini (EPC) cells were significantly enhanced (2.0-fold). Furthermore, the median lethal dose (LD50) of ΔpreA was 7.6-fold higher than that of the wild-type strain, which illustrates that the virulence of the mutant was significantly enhanced. This finding is also supported by the cytotoxicity test results, which showed that the toxicity of ΔpreA to EPC cells was enhanced 1.3-fold relative to the wild type. Conversely, tolerance test results showed that oxidative stress resistance of ΔpreA decreased 5.9-fold compared to with the wild-type strain. The results suggest that preA may negatively regulate the virulence of A. veronii TH0426 through the regulation of resistance to oxidative stress. These insights will help to further elucidate the function of preA and understand the pathogenesis of A. veronii.

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