Dynamic characteristics of a switch and crossing on the West Coast main line in the UK

Railway switches and crossings constitute a small fraction of linear track length but consume a large proportion of the railway track system maintenance budget.While switch and crossing(S&C)faults rarely prevent trains from running,switches and crossings are the source of many faults and need continual attention.On the rare occasions when trains are prevented from running the cost of the disruption is very high.Condition monitoring of the point operating equipment that moves the switchblades has been in use for many years but condition monitoring of the state of the switch in terms of the support and mechanical damage as trains pass over has only recently started to become possible.To this end,it is important to understand the correlation between S&C faults and sensor data that can detect those faults.This paper assesses some of the data collected from multiple sensors variously positioned on and around a switch and crossing on the UK mainline for a few days of normal train operation.Accelerometers,geophones,and strain gauges were installed at the locations where they were anticipated to be most useful.Forces at the load transfer point on the crossing nose were estimated from two separate strain gauge bridges and possible use of acceleration on the crossing is discussed.Correlations between different data are analysed and assessed and correlation between peak estimated load transfer forces and accelerations is presented.Based on the analysis,conclusions are drawn about the different types of dynamic information around S&Cs that can be obtained from a variety of sensor types.

Safety Assessment of Closed-Loop Level Crossing Control Systems by Means of STAMP(Systems-Theoretic Accident Model and Processes)

There have been a large number of accidents at level crossings of railways and this has been considered to be a significant issue to be solved for the realization of safe and stable railway transport.A conventional level crossing control system is characterized by the use of two types of electronic train detectors;one detects a train approaching to a level crossing section and the other then detects the train having left the level crossing.By contrast,closed-loop level crossing control systems in which level crossing control equipment and train-borne equipment communicate with each other have been advocated and are expected to serve as an effective solution to the abovementioned issue.This paper describes the following three types of closed-loop level crossing control systems:decentralized level crossing control system,fully-centralized comprehensive level crossing control system and fully-centralized individual level crossing control system.This paper then assesses the safety of these systems in comparison to the conventional level crossing control system.For the purpose of the assessment of their safety,a new accident analysis model called STAMP(systems theoretic accident model and processes)that is suitable for software intensive systems is used to clarify the advantage of the proposed three types of level crossing control systems in terms of safety.

Railway Accident Prevention and Infrastructure Protection

Railway accident prevention and protection are a key part of a wider picture of transport safety. The rail sector thus needs to improve its knowledge of trespassing and suicide, including at level crossing, in order to work out suitable responses by analyzing measures already taken in various countries, Governments, the rail industry and road organizations have been implementing a variety of countermeasures for many years to improve railway safety. These actions are substantial and have resulted in a continuing decrease in the number and the severity of accidents. This paper presents existing suitable techniques that are used in the preventative measures targeted to reduce railway suicides, trespassing and level crossing user accidents. It describes them in terms of their capability to effectively reduce accidents, their cost-effectiveness and their integration within the railway transport system as a whole.

Overall Selection Design Based on the Mega Highway Bridge Project

In the continuous development of the modern highway and bridge engineering industry,the reasonable selection of mega highway bridges and their design is crucial.Based on this,this paper takes the actual bridge project as an example,and analyses the overall selection design of such highway bridges,including the basic overview of the project,the basic selection principle of mega highway bridge project structure and its design strategy,etc.,to provide scientific reference for its selection design.

Design and Manufacture an Elastic Neutron Scattering Spectrometer at the Dalat Nuclear Reactor

The objective of this study is to design an elastic neutron scattering system according to the angle with a sample using thermal neutron beam at the Dalat Nuclear Reactor (DNR). The system is used for research and training in the field of material structure analysis by neutron scattering and diffraction techniques. It is designed on the basis of inheriting the neutron measurement spectrometer systems at the DNR and the scattered neutron measurement systems in the world. The measuring system, which was installed at the horizontal channel 4 of the DNR, consists of 5-helium-3 detectors and a fully electronic system to record the scatter counts and a mechanical system with the possibility of rotating at 15˚-75˚ angles. The constructed system is tested for evaluation of the accuracy, stability and reliability of the mechanical and electronic systems of moving detectors by angles.

Review of research on high-speed railway aerodynamics in China

High-speed railway aerodynamics is the key basic science for solving the bottleneck problem of high-speed railway development.This paper systematically summarizes the aerodynamic research relating to China’s high-speed railway network.Seven key research advances are comprehensively discussed,including train aerodynamic drag-reduction technology,train aerodynamic noise-reduction technology,train ventilation technology,train crossing aerodynamics,train/tunnel aerodynamics,train/climate environment aerodynamics,and train/human body aerodynamics.Seven types of railway aerodynamic test platform built by Central South University are introduced.Five major systems for a high-speed railway network—the aerodynamics theoretical system,the aerodynamic shape(train,tunnel,and so on)design system,the aerodynamics evaluation system,the 3D protection system for operational safety of the high-speed railway network,and the high-speed railway aerodynamic test/computation/analysis platform system—are also introduced.Finally,eight future development directions for the field of railway aerodynamics are proposed.For over 30 years,railway aerodynamics has been an important supporting element in the development of China’s high-speed railway network,which has also promoted the development of high-speed railway aerodynamics throughout the world.