Cause Analysis and Improvement Measures for Maglev Train Brake Release Failure in Beijing Subway Line S1

Objective The maglev train of Beijing Subway Line S1 had a brake release failure during operation, impacting line normal operation. Therefore, it is necessary to find out the exact cause of the fault and put forward improvement measures. Method The working principle of the train brake control system of Beijing Subway Line S1 is briefly described. By using fishbone diagram analysis method, eight main causes of train brake release failure are identified , and the triggers of each cause are listed. Considering the actual situation of train fault, the cause set of train brake release on this line is further sorted out, and the root cause of train breaking failure on this line is determined using investigation method. The characteristics of solenoid valve are analyzed and corresponding improvement measures are taken. Result & Conclusion The solenoid valve stuck in EP (electro-pneumatic solenoid valve) module of train PBCU (pneumatic brake control unit) on this line is the root cause for train brake release failure. After replacing the balanced solenoid valve produced by MAC Valves, Inc.in the United States with the stop solenoid valve produced by German NASS Magnet GmbH, the train brake release failure on this line is effectively tackled.