An experimental study has been carried out to investigate the effect of sanding on the electrical isolation of a wheel/rail contact. Sand is applied to the wheel/rail interface to increase adhesion in both braking and traction. Train detection, for signalling purposes, can be by means of track circuits. Signalling block occupancy is triggered by the wheelset of the train ,shorting out' the track circuit. Sand in the wheel/rail interface means that contact between the wheelsets and the track may be compromised, inhibiting train identification. Static tests were performed using sections cut from wheels and rail and dynamic tests on a twin disc machine where rail and wheel steel discs are loaded together and driven under controlled conditions of rolling and slip. The electrical circuit used was a simplified simulation of the TI21 track circuit. The application of sand was carried out under a range of mild and severe test conditions. The results indicated that a transition exists in the amount of sand applied, below which there is a measurable, but not severe, change in voltage, but above which the contact conductance decreases by an order of magnitude. A model of electrical isolation has been developed assuming either full disc separation by a sand layer or partial disc contact with some sand present. At their present stage of development the test methods are best used as a means to qualitatively assess relative effects on electrical isolation of different contaminants.
Wheel/rail contact isolation due to track contamination
2003
9 Seiten, 14 Bilder, 1 Tabelle, 6 Quellen
Conference paper
English
Wheel/rail contact isolation due to track contamination
British Library Conference Proceedings | 2003
|Static wheel/rail contact isolation due to track contamination
Tema Archive | 2006
|Static wheel/rail contact isolation due to track contamination
British Library Online Contents | 2006
|Static wheel-rail contact isolation due to track contamination
Online Contents | 2006
|Static wheel/rail contact isolation due to track contamination
SAGE Publications | 2006
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