railway freight
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2021 ◽  
Vol 7 (5) ◽  
pp. 501-519

Under the "weak state" regime of modern China, it was difficult for the country’s modernization process to develop without the effective intervention of a centralized state. In the process of government governance, absorbing social organizations and civil forces as agents had proved to be an effective method. Beiyang government’s governance strategy of ‘using agents to regulate agents’ in the documentary railway billing business could be regarded as typical of the diversity of government management. Qing Dynasty, government departments were not directly responsible for railway freight for various reasons, instead, they allowed railway transshipment companies to act as agents for freight management. Then transshipment companies gradually became an obstacle to Beiyang government’s reform on freight transport. However, under the Republic of China, the new-style bank discovered a benign opportunity to develop documentary railway billing service and created a bottom-up institutional reform model. Through the service, the bank became the new agent for the supervision of the transshipment company, which not only regulated the operation, but also forced railroad bureaus in the Yangzi Delta to be primarily responsible for railway freight. The Central Ministry of Transportation of Beiyang Government decided to promote this agency governance model and billing service nationwide. Received 11th January 2021; Revised 2nd June 2021; Accepted 20th July 2021


2021 ◽  
Vol 2021 ◽  
pp. 1-13
Author(s):  
Jian Mu ◽  
Jing Zeng ◽  
Qunsheng Wang ◽  
Hutang Sang

The polygonal wear around the wheel circumference could pose highly adverse influences on the wheel/rail interactions and thereby the performance of the vehicle system. In this study, the effects of wheel polygonalisation on the dynamic responses of a freight wagon are investigated through development and simulations of a comprehensive coupled vehicle-track dynamic model. The model integrates flexible ballasted track and wheelsets subsystem models so as to account for elastic deformations caused by impact loads induced by the wheel polygonalisation. Subsequently, the vehicles with low-order polygonal wear, whether in empty or loaded conditions, are simulated at different speeds considering different amplitudes and harmonic orders of the wheel polygonalisation and thus the mapping relation between wheel/rail impact force and wheel polygonalisation is obtained. The results reveal that the low-order wheel polygonalisation except 1st order and 3rd order can give rise to high-frequency impact loads at the wheel/rail interface and excite 1st-bend modes of the wheelset and “P2 resonance” leading to high-magnitude wheel/rail contact force at the corresponding speed.


2021 ◽  
Vol 11 (19) ◽  
pp. 9077
Author(s):  
Jan Chocholac ◽  
Roman Hruska ◽  
Stanislav Machalik ◽  
Dana Sommerauerova ◽  
Jiri Krupka

The topic of global warming is and will continue to be a crucial topic of this millennium. Freight transport, as a producer of greenhouse gas (hereinafter GHG) emissions, makes a significant contribution to the greenhouse effect. Large supply chains and large volumes of freight transport, which imply the production of significant volumes of GHG emissions, characterize the automotive industry (hereinafter AI). Thanks to these premises, it is necessary to seek and develop tools for reducing the volume of GHG emissions produced from the logistic activities of the AI, while maintaining the required level of logistic services. The assumptions for the calculation of GHG emissions from railway freight transport (hereinafter RFT) in the AI were identified through the use of semi-structured interviewing. Available railway freight GHG emission calculators were identified and analyzed from the perspective of suitability for the AI using a comparative content analysis. The main result of this manuscript is the proposal of a fully customized approach to GHG emission calculations in RFT for the AI. This approach was proposed, applied, and verified in the form of an interpretative case study. The use of this approach can be expected in support of logistic planning and decision making.


Author(s):  
Jin Zeng ◽  
Fangrong Qi ◽  
Shaoyuan Guo ◽  
Jinhao Zeng

This study aims to establish criteria to evaluate performance in railway freight pricing policy and to strengthen the marketing ability of the railway freight enterprise. The evaluation method used in our study is known as the improved grey relation analysis evaluation. Fifteen factors that influence freight pricing strategy are selected in this paper to establish a freight rate evaluation index system and comprehensive evaluation index values for monthly freight rates are calculated. The improved grey relation analysis not only considers the relation between each index and freight rate but also examines the relationship between each index. We find that the comprehensive evaluation state using the improved grey relation analysis evaluation method can better fit the 2015–2017 changes in monthly railroad freight revenue than the traditional grey relation analysis evaluation. Furthermore, an optimal pricing model for freight shipping by train is built and calculated using the bi-level programming model. Finally, the S Railway Bureau’s actual coal transportation in 2017 is taken as an experiment to support the validity of the improved grey relation analysis method. We find that when the monthly results of improved grey evaluation grades are compared with the grade evaluation of the gap between the historical shipping coal rates and the optimal freight shipping rates, the comparison of results matches well. The research work is helpful to policymakers who need to judge the performance of the market price.


Author(s):  
Jian Mu ◽  
Jing Zeng ◽  
Qunsheng Wang ◽  
Hutang Sang

In order to comprehensively consider the dynamic behavior of vehicle system and the contact forces between wheel and rail, the vehicle-track coupling model is established considering the flexible wheelset and rail modal characteristics. Guyan reduction theory is introduced to reduce the degrees of freedom of wheelset and rail and to improve the calculation speed. Due to small axle load variation of freight wagon operating on the special line for the coal transportation, the vehicles with different speeds and wheel flat lengths, whether in empty or loaded conditions, are simulated and then the mapping relations between the flat lengths and wheel/rail impact force are obtained. Subsequently, the fitting functions for the empty and loaded vehicles are fitted to quantitatively detect the wheel flat by trackside equipment. The results indicate that the fitting function of empty vehicle has a better effect on predicting the flat length within 6% error since wheel/rail contact force of empty vehicle induced by wheel flat increases with the increase of flat length, while that of loaded vehicle presents a parabola variation trend at low speed and increasing trend at higher speed.


Author(s):  
Sławomir Żak ◽  
Terese Rauckyte-Żak

AbstractThis paper presents results of the research carried out on a system made to pretreat the effluents produced in water treatment of dirty surfaces of railway transportation means (RTMs) mainly G, H, T and incidental F classes of rolling stock according to the International Union of Railways (IURs). The installation was designed for coagulation–flocculation pretreatment of wastewater with flow accelator reactor (AR) in total amount of up to 75.0 m3 day−1. The raw wastewater (RW) was characterized by a significant diversity of loads: TSS (total suspended solids), TDS (total dissolved solids), COD & BOD5 (chemical & biochemical oxygen demand) and periodically it had extremely different colors, Ta (turbidity) and EE (etheric extract). The application of two-stage, coupled acid-alkali or alkaline-acid coagulation using aluminum coagulants with final flocculation and phase separation in the system implemented in practice to treat the wastewater of statistically typical composition, usually allowed to removal, accordingly: EE & TSS > 99% and to eliminate completely color and Ta. However, COD and BOD5 were removal at different levels, depending on both initial concentrations and chemical composition of load pools registered in the RW, and a type of coagulation used. The use of pre-oxidation with aqueous solutions of hydrogen peroxide or peracetic acid coupled with coagulation based only on aluminum coagulants helps to achieve equal levels of removal of the basic indicator values and a sanitary clean stream of pretreated wastewater (PW) with a colony forming unit (CFU) of <100 ml−1.


Author(s):  
Honghui Li ◽  
Hongkun Wang ◽  
Ziwen Xie ◽  
Mengqi He

As the key running part of the railway freight transportation system, the wheel not only bears the load of the vehicle, but also ensures the running and steering of the car body on the rails. The frequent high-speed friction with the rail and brake is the main reason for early failure of wheelset tread. Therefore, real-time status monitoring and early fault diagnosis of wheel treads have become key technical issues that must be solved in the reform of the railway freight maintenance system. In this paper, an adaptive hybrid Simulated Annealing Cuckoo Search algorithm (SA-ACS) is proposed and applied to the Deep Belief Network (DBN). The SA-ACS-DBN algorithm is used to improve the training speed and convergence accuracy of the diagnosis model. Finally, it is found through the comparison experiment of wheel tread fault data that the data results prove the feasibility of the SA-ACS-DBN model in the application of wheelset fault diagnosis.


Author(s):  
Chikusela Sikazwe ◽  
Richard Kasongo ◽  
Lubinda Haabazoka ◽  
Erastus M. Mwanaumo ◽  
Wellington Didibhuku Thwala

Energies ◽  
2021 ◽  
Vol 14 (12) ◽  
pp. 3410
Author(s):  
Michał Opala ◽  
Jarosław Korzeb ◽  
Seweryn Koziak ◽  
Rafał Melnik

The article discusses the use of pivot bearing friction liners, made of selected materials, in railway freight wagons’ spherical centre bowls. Comparative studies on the effect of suspension dynamics on the equivalent stresses in the liner material were carried out using the finite element method and multibody simulation. The results show the magnitude and location of the highest stresses in the liner with varying input loads, friction coefficients and interacting materials. The analysis is a basis for a simulation method for predicting the fatigue life of the suspension friction liner placed in the centre bowl between the bogie frame and the vehicle body.


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