Special edition paper

Overhead contact line equipment is important equipment that supplies power to trains. In order thus to maintain the soundness of the equipment, we inspect wearing depth of contact wires and positions (height and deviation) of overhead contact lines a few times a year using inspection cars. Some equipment, however, cannot be measured by inspection cars, so that is measured or just visually checked and manually measured only about once a year. One way to acquire accurate information of the condition of such equipment is by shortening the inspection period, but that would be quite difficult to implement due to a considerable increase in the amount of work. Furthermore, some items such as temperature of compression joints of feeders and displacement of springs of STBs constantly vary according to load current and weather. Depending on the timing of the inspection, we may not be able to check the items at their poorest condition. We thus developed an overhead contact line equipment monitoring system where equipment measurement devices attached to overhead contact lines periodically measure temperature and displacement and transmit that measurement data to trains running there in commercial operation. In this way, the monitoring system enables highly frequent inspection. In this article, we will give an overview of the system and report on some of the field test results