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Lam H.F.,City University of Hong Kong | Wong M.T.,MTR Corporation
Lecture Notes in Electrical Engineering | Year: 2012

This paper reports a feasibility study in the use of measured modal parameters of in-situ concrete sleepers to detect possible damage of the underlying railway ballast. There are many methods developed for monitoring and damage detection of the rail track. However, the detection of ballast damage still heavily relies on visual inspection and destructive core test. In this feasibility study, a typical plain ballasted track with concrete sleeper is considered. In the proposed method, ballast under sleeper is modelled as an elastic foundation. Ballast damage is defined as ballast degradation and ballast cementation with the accumulation of fines. When the ballast is damaged, the stiffness provided in supporting the sleeper will reduce, and the vibration characteristic of the in-situ sleeper will be altered. This paper studies the possibility to detect the damage status of ballast under a sleeper by monitoring the vibration of the corresponding sleeper through simple impact hammer test. This paper not only presented the theoretical development but also the numerical verifications. © 2012 Springer-Verlag. Source


Lam H.F.,City University of Hong Kong | Wong M.T.,MTR Corporation
Procedia Engineering | Year: 2011

This paper reports a feasibility study in the use of measured modal parameters of in-situ concrete sleepers to detect possible damage of the underlying railway ballast. There are many methods developed for monitoring and damage detection of the rail track. However, the detection of ballast damage still heavily relies on visual inspection and destructive core test. In this feasibility study, a typical plain ballasted track with concrete sleeper is considered. In the proposed method, ballast under sleeper is modelled as an elastic foundation. Ballast damage is defined as ballast degradation and ballast cementation with the accumulation of fines. When the ballast is damaged, the stiffness provided in supporting the sleeper will reduce, and the vibration characteristic of the in-situ sleeper will be altered. This paper studies the possibility to detect the damage status of ballast under a sleeper by monitoring the vibration of the corresponding sleeper through simple impact hammer test. This paper not only presented the theoretical development but also the numerical verifications. Source


John H.C.M.,MTR Corporation
HKIE Transactions Hong Kong Institution of Engineers | Year: 2014

In this information age, modern buildings are usually equipped with information technology (IT) cabling systems for different telecommunication services and new electronic systems. As IT cabling designers, it is important to optimally plan the IT cable distributions and pathways based on the building layouts and required cable quantities. This paper is to consider three quantitative design methods for cable distribution and pathway systems, namely the calculation of serviceable area radius of cabling floor distributor, the estimation of the IT cable capacity of cable pathways and the calculation of the impact of cable trunking bends towards the cable trunking cable capacity. In this paper, the mathematical derivations and real application examples of the design methods are presented. Literature supports of the methods are also sought. © 2014 © 2014 Taylor & Francis. Source


Leung P.C.M.,City University of Hong Kong | Leung P.C.M.,MTR Corporation | Lee E.W.M.,City University of Hong Kong
Applied Energy | Year: 2013

According to the records of Hong Kong rail operator, MTR Corporation, the weekly electrical consumption of each railway station ranges from 18. MWh to 230. MWh. Since the electrical consumption of stations is a major factor in the planning of infrastructure, a good prediction of the electrical consumption will greatly assist in the design of the station infrastructure. This study develops an intelligent approach to predict the energy consumption of railway stations. Multi-layered Perceptron (MLP) is adopted to mimic the non-linear correlation between energy consumption, the spatial design of the station, meteorological factors and also the usage of the 19 stations selected. Coefficient of correlation is obtained between the MLP predicted results and the actual collected data to evaluate the performance of the prediction. We apply statistical approach to assess the performance of the developed MLP model. It shows that minimum coefficient of correlation is 0.96 with a 95% confidence level which is considered sufficient for engineering application. This approach is also adopted to predict the profile of the weekly electrical consumption of a selected station. The predicted profile reasonably agrees with that of the actual consumption. This study develops a useful tool to estimate the electrical power consumption of new MTR stations. © 2012 Elsevier Ltd. Source


Leung C.M.,Hong Kong Polytechnic University | Or S.W.,Hong Kong Polytechnic University | Ho S.L.,Hong Kong Polytechnic University | Lee K.Y.,MTR Corporation
IEEE Sensors Journal | Year: 2014

Novel power-supply-free, surface-mount-type magnetoelectric passive current sensors were developed and integrated with a four-channel, 2.4-GHz wireless communication (transmitter and receiver) unit to form a new generation of wireless condition monitor for train traction systems. The wireless condition monitor was deployed in a field study on the East Rail Line in Hong Kong. Four pairs of magnetoelectric passive current sensors and single-channel wireless transmitters were installed, respectively, on and near the electric cables of four electric motor drives located underneath the 2nd, 5th, 8th, and 11th cars of a 12-car mainline train. The four-channel wireless receiver was housed in the driver's cab of the train to provide real-time wireless monitoring of the current signatures of the four electric motor drives due to the operation of the train traction system in steady-state and acceleration conditions. The monitored current signatures were postprocessed to obtain the distributions of the ratio of harmonic-to-fundamental current, their total harmonic distortions and power factors as well as the frequency spectra. A practical implication and correlation of the postprocessed data with the operating conditions of the train traction system was established for application of the proposed wireless condition monitor as train traction system monitor. © 2014 IEEE. Source

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