Detection of Derailment of Freight Cars Using Mechanical Contact Sensors

Abstract

In the case of long freight trains, there may be a delay in recognizing a derailment if a freight car that is far from the locomotive derails. In such cases, there is concern that the damage caused by the derailment may increase. Therefore, early detection of derailments is required. On the other hand, it is difficult to apply the derailment detection method using vibration acceleration sensors for passenger cars to freight cars. This is due to the unique characteristics of freight cars, such as the fact that they are subject to significant changes in running condition and running on a wide variety of tracks. Therefore, a derailment detection method applying mechanical contact sensors, which are easy to detect, was studied. The reason for considering the applying of contact sensors is that past studies have shown that certain parts of freight car bogies contact with other parts or rails during derailment. In this study, two locations were selected as the installation points of contact sensors on the bogies based on past findings and simulation results. Derailment detection tests were conducted by derailing a bogie with contact sensors installed at selected locations on a real track to evaluate the detection performance. As a result, it was found that the contact sensors were able to detect derailment immediately after it occurred.