Abstract
The contact wire breaking accident caused by the arc between the contact wire and the pantograph happens rarely in the DC electric railway system. The contact wire breaking phenomenon is discussed and investigated based on the experimental data performed 30 years ago. The material of the contact strip and the contact wire has changed, however, and the breaking characteristics of the contact wire caused by the arc should be different. In this paper, the contact wire breaking characteristics are carefully investigated using the recent materials. It is cleared that the breaking index of 750As is approximately appropriate in the limited condition and the other breaking condition is summarized based on the experimental data more than 400 times.